@techreport{StawskiLauth2024, type = {Working Paper}, author = {Stawski, Theresa Paola and Lauth, Hans-Joachim}, title = {The Stateness Index (StIx) - Conceptual Design and Empirical Results}, doi = {10.25972/OPUS-34761}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347616}, pages = {32}, year = {2024}, abstract = {Exploring and explaining diversity and patterns of stateness is crucial for understanding causes of efficiency, duration, or the collapse of a state. The new Stateness Index (StIx) contributes to the conceptual and analytical debate on stateness and state fragility. StIx is a tool for measuring stateness and state quality since 1950 that includes country-ranking through aggregated and disaggregated data to advance performance comparison and policy analysis. This article first sums up the main theoretical aspects, followed by descriptive results.}, subject = {Begrenzte Staatlichkeit}, language = {en} } @phdthesis{Kleineisel2024, author = {Kleineisel, Jonas}, title = {Variational networks in magnetic resonance imaging - Application to spiral cardiac MRI and investigations on image quality}, doi = {10.25972/OPUS-34737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347370}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Acceleration is a central aim of clinical and technical research in magnetic resonance imaging (MRI) today, with the potential to increase robustness, accessibility and patient comfort, reduce cost, and enable entirely new kinds of examinations. A key component in this endeavor is image reconstruction, as most modern approaches build on advanced signal and image processing. Here, deep learning (DL)-based methods have recently shown considerable potential, with numerous publications demonstrating benefits for MRI reconstruction. However, these methods often come at the cost of an increased risk for subtle yet critical errors. Therefore, the aim of this thesis is to advance DL-based MRI reconstruction, while ensuring high quality and fidelity with measured data. A network architecture specifically suited for this purpose is the variational network (VN). To investigate the benefits these can bring to non-Cartesian cardiac imaging, the first part presents an application of VNs, which were specifically adapted to the reconstruction of accelerated spiral acquisitions. The proposed method is compared to a segmented exam, a U-Net and a compressed sensing (CS) model using qualitative and quantitative measures. While the U-Net performed poorly, the VN as well as the CS reconstruction showed good output quality. In functional cardiac imaging, the proposed real-time method with VN reconstruction substantially accelerates examinations over the gold-standard, from over 10 to just 1 minute. Clinical parameters agreed on average. Generally in MRI reconstruction, the assessment of image quality is complex, in particular for modern non-linear methods. Therefore, advanced techniques for precise evaluation of quality were subsequently demonstrated. With two distinct methods, resolution and amplification or suppression of noise are quantified locally in each pixel of a reconstruction. Using these, local maps of resolution and noise in parallel imaging (GRAPPA), CS, U-Net and VN reconstructions were determined for MR images of the brain. In the tested images, GRAPPA delivers uniform and ideal resolution, but amplifies noise noticeably. The other methods adapt their behavior to image structure, where different levels of local blurring were observed at edges compared to homogeneous areas, and noise was suppressed except at edges. Overall, VNs were found to combine a number of advantageous properties, including a good trade-off between resolution and noise, fast reconstruction times, and high overall image quality and fidelity of the produced output. Therefore, this network architecture seems highly promising for MRI reconstruction.}, subject = {Kernspintomografie}, language = {en} } @phdthesis{Berberich2024, author = {Berberich, Oliver}, title = {Lateral Cartilage Tissue Integration - Evaluation of Bonding Strength and Tissue Integration \(in\) \(vitro\) Utilizing Biomaterials and Adhesives}, doi = {10.25972/OPUS-34602}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346028}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Articular cartilage defects represent one of the most challenging clinical problem for orthopedic surgeons and cartilage damage after trauma can result in debilitating joint pain, functional impairment and in the long-term development of osteoarthritis. The lateral cartilage-cartilage integration is crucial for the long-term success and to prevent further tissue degeneration. Tissue adhesives and sealants are becoming increasingly more popular and can be a beneficial approach in fostering tissue integration, particularly in tissues like cartilage where alternative techniques, such as suturing, would instead introduce further damage. However, adhesive materials still require optimization regarding the maximization of adhesion strength on the one hand and long-term tissue integration on the other hand. In vitro models can be a valuable support in the investigation of potential candidates and their functional mechanisms. For the conducted experiments within this work, an in vitro disc/ring model obtained from porcine articular cartilage tissue was established. In addition to qualitative evaluation of regeneration, this model facilitates the implementation of biomechanical tests to quantify cartilage integration strength. Construct harvesting for histology and other evaluation methods could be standardized and is ethically less questionable compared to in vivo testing. The opportunity of cell culture technique application for the in vitro model allowed a better understanding of cartilage integration processes. Tissue bonding requires chemical or physical interaction of the adhesive material and the substrate. Adhesive hydrogels can bind to the defect interface and simultaneously fill the gap of irregularly shaped defect voids. Fibrin gels are derived from the physiological blood-clot formation and are clinically applied for wound closure. Within this work, comparisons of different fibrin glue formulations with the commercial BioGlue® were assessed, which highlighted the need for good biocompatibility when applied on cartilage tissue in order to achieve satisfying long-term integration. Fibrin gel formulations can be adapted with regard to their long-term stability and when applied on cartilage disc/ring constructs improved integrative repair is observable. The kinetic of repairing processes was investigated in fibrin-treated cartilage composites as part of this work. After three days in vitro cultivation, deposited extracellular matrix (ECM) was obvious at the glued interface that increased further over time. Interfacial cell invasion from the surrounding native cartilage was detected from day ten of tissue culture. The ECM formation relies on molecular factors, e.g., as was shown representatively for ascorbic acid, and contributes to increasing integration strengths over time. The experiments performed with fibrin revealed that the treatment with a biocompatible adhesive that allows cartilage neosynthesis favors lateral cartilage integration in the long term. However, fibrin has limited immediate bonding strength, which is disadvantageous for use on articular cartilage that is subject to high mechanical stress. The continuing aim of this thesis was to further develop adhesive mechanisms and new adhesive hydrogels that retain the positive properties of fibrin but have an increased immediate bonding strength. Two different photochemical approaches with the advantage of on-demand bonding were tested. Such treatment potentially eases the application for the professional user. First, an UV light induced crosslinking mechanism was transferred to fibrin glue to provide additional bonding strength. For this, the cartilage surface was functionalized with highly reactive light-sensitive diazirine groups, which allowed additional covalent bonds to the fibrin matrix and thus increased the adhesive strength. However, the disadvantages of this approach were the multi-step bonding reactions, the need for enzymatic pretreatment of the cartilage, expensive reagents, potential UV-light damage, and potential toxicity hazards. Due to the mentioned disadvantages, no further experiments, including long-term culture, were carried out. A second photosensitive approach focused on blue light induced crosslinking of fibrinogen (RuFib) via a photoinitiator molecule instead of using thrombin as a crosslinking mediator like in normal fibrin glue. The used ruthenium complex allowed inter- and intramolecular dityrosine binding of fibrinogen molecules. The advantage of this method is a one-step curing of fibrinogen via visible light that further achieved higher adhesive strengths than fibrin. In contrast to diazirine functionalization of cartilage, the ruthenium complex is of less toxicological concern. However, after in vitro cultivation of the disc/ring constructs, there was a decrease in integration strength. Compared to fibrin, a reduced cartilage synthesis was observed at the defect. It is also disadvantageous that a direct adjustment of the adhesive can only be made via protein concentration, since fibrinogen is a natural protein that has a fixed number of tyrosine binding sites without chemical modification. An additional cartilage adhesive was developed that is based on a mussel-inspired adhesive mechanism in which reactivity to a variety of substrates is enabled via free DOPA amino acids. DOPA-based adhesion is known to function in moist environments, a major advantage for application on water-rich cartilage tissue surrounded by synovial liquid. Reactive DOPA groups were synthetically attached to a polymer, here POx, to allow easy chemical modifiability, e.g. insertion of hydrolyzable ester motifs for tunable degradation. The possibility of preparing an adhesive hybrid hydrogel of POx in combination with fibrinogen led to good cell compatibility as was similarly observed with fibrin, but with increased immediate adhesive strength. Degradation could be adjusted by the amount of ester linkages on the POx and a direct influence of degradation rates on the development of integration in the in vitro model could be shown. Hydrogels are well suited to fill defect gaps and immediate integration can be achieved via adhesive properties. The results obtained show that for the success of long-term integration, a good ability of the adhesive to take up synthesized ECM components and cells to enable regeneration is required. The degradation kinetics of the adhesive must match the remodeling process to avoid intermediate loss of integration power and to allow long-term firm adhesion to the native tissue. Hydrogels are not only important as adhesives for smaller lesions, but also for filling large defect volumes and populating them with cells to produce tissue engineered cartilage. Many different hydrogel types suitable for cartilage synthesis are reported in the literature. A long-term stable fibrin formulation was tested in this work not only as an adhesive but also as a bulk hydrogel construct. Agarose is also a material widely used in cartilage tissue engineering that has shown good cartilage neosynthesis and was included in integration assessment. In addition, a synthetic hyaluronic acid-based hydrogel (HA SH/P(AGE/G)) was used. The disc/ring construct was adapted for such experiments and the inner lumen of the cartilage ring was filled with the respective hydrogel. In contrast to agarose, fibrin and HA-SH/P(AGE/G) gels have a crosslink mechanism that led to immediate bonding upon contact with cartilage during curing. The enhanced cartilage neosynthesis in agarose compared to the other hydrogel types resulted in improved integration during in vitro culture. This shows that for the long-term success of a treatment, remodeling of the hydrogel into functional cartilage tissue is a very high priority. In order to successfully treat larger cartilage defects with hydrogels, new materials with these properties in combination with chemical modifiability and a direct adhesion mechanism are one of the most promising approaches.}, subject = {Knorpel}, language = {en} } @phdthesis{Shaikh2024, author = {Shaikh, Muhammad Haroon}, title = {Nicht-h{\"a}matopoetische lymphoide Stromazellen aktivieren alloreaktive CD4\(^+\) T-Zellen in der Initiierung der akuten Graft-versus-Host Disease}, doi = {10.25972/OPUS-25201}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252015}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In der Initiationsphase der akuten Graft-versus-Host Erkrankung (GvHD) werden CD4+ T-Zellen in den lymphatischen Organen durch h{\"a}matopoietische Antigen-pr{\"a}sentierende Zellen aktiviert. Im Gegensatz dazu, werden in der Effektorphase CD4+ T-Zellen von nicht-h{\"a}matopoetischen Zellen im D{\"u}nndarm aktiviert. Wir stellten die Hypothese auf, dass alloreaktive CD4+ T-Zellen nach allogener h{\"a}matopoetischer Zelltransplantation, welche in der Initiationsphase der aGvHD vorwiegend in die sekund{\"a}ren lymphatischen Organe migrieren, dort durch nicht-h{\"a}matopoetische Lymphknoten-Stromazellen {\"u}ber die Erkennung von MHC-Klasse II aktiviert werden. Um diese Hypothese zu testen, setzten wir ein von allogenen CD4+ T-Zellen-abh{\"a}ngiges MHC Major Mismatch aGvHD Mausmodell ein, um diese Zusammenh{\"a}nge n{\"a}her zu erforschen. Mittels Biolumineszenz-Bildgebung und dreidimensionale Lichtblattmikroskopie und Durchflusszytometrie-Analysen von fr{\"u}heren Zeitpunkten nach einer alloHCT bzw. im Anfangsstadium der aGvHD konnten wir zeigen, dass allogene T-Zellen exklusiv in die Milz, Lymphknoten und die Peyerschen Plaques migrieren und nicht in die intestinale Lamina propria. Indem wir transgene Mauslinien verwendeten, die keine oder eine nur partielle komplette h{\"a}matopoietische Antigenpr{\"a}sentation aufwiesen, konnten wir eine sehr fr{\"u}h auf die alloHCT folgende allogene CD4+ T-Zellaktivierung in den lymphoiden Organen von MHCIIΔCD11c and MHCIIΔ Knochenmark-Chim{\"a}ren nachweisen. Aufgrund des, bei den MHCIIΔ Knochenmarks-Chim{\"a}ren auftretenden Versagens der negativen Thymusselektion und die daraus resultierende autoreaktive Immunreaktionen nach einer syngenen HCST stellte sich heraus, dass dies ein ungeeignetes Modell f{\"u}r die Untersuchung der Pr{\"a}sentation nicht-h{\"a}matopoetischer Antigene bei GvHD ist. Um diese Herausforderung zu bew{\"a}ltigen, generierten wir MHCIIΔVav1 M{\"a}use bei denen die MHC-Klasse-II-Expression auf allen h{\"a}matopoetischen Zellen fehlt. MHCIIΔVav1 M{\"a}use entwickelten eine aGvHD, wobei die Lymphknoten-Stromazellen dieser Tiere allogene CD4+ T-Zellen in gemischten Lymphozytenreaktionen aktivieren konnten. Ebenso konnten mesenteriale Lymphknoten von CD11c.DTR-M{\"a}usen, die zuvor in eine MHCIIΔ Maus transplantiert wurden, CD4+ T-Zellen in vivo aktivieren, wodurch die Lymphknoten-Stromazellen eindeutig als nicht-h{\"a}matopoetische Antigen-pr{\"a}sentierende Zellen der lymphoiden Organe nachgewiesen werden konnten. {\"U}ber das Cre/loxP-System konnten wir Knockout-M{\"a}use mit fehlender MHCII-Expression in Subpopulationen von Lymphknoten-Stromazellen generieren und verwendeten dann Einzelzell-RNA-Sequenzierung. Hier w{\"a}hlten wir Ccl19 und VE-Cadherin aus, um unsere Analyse spezifisch auf die fibroblastischen retikul{\"a}ren Zellen bzw. Endothelzellen der Lymphknoten zu konzentrieren. Bei MHCIIΔCcl19 M{\"a}usen war die Aktivierung alloreaktiver CD4+ T-Zellen in der Initiationsphase der aGvHD m{\"a}ßig reduziert, w{\"a}hrend das Fehlen von MHCII auf den fibroblastischen retikul{\"a}ren Zellen zu einer Hyperaktivierung allogener CD4+ T-Zellen f{\"u}hrte, was wiederum eine schlechtere {\"U}berlebensrate der M{\"a}use zur Folge hatte. Dieser Ph{\"a}notyp wurde durch regulatorische T-Zellen moduliert, die in der Lage waren, H2-Ab1fl M{\"a}use von den Folgen von GvHD zu retten, jedoch nicht die MHCIIΔCcl19. Ein Knock-out von MHCII auf Endothelzellen von MHCIIΔVE-Cadherin M{\"a}usen, f{\"u}hrte in der Initiationsphase der GvHD nur zu einer m{\"a}ßig reduzierten Aktivierung von CD4+ T-Zellen. Umgekehrt zeigten MHCIIΔVE-Cadherin M{\"a}use im Langzeit{\"u}berleben jedoch einen protektiven Ph{\"a}notyp verglichen mit wurfgeschwister H2-Ab1fl M{\"a}usen. Um die Bedeutung der MHCII-Antigenpr{\"a}sentation der Endothelzellen zu untersuchen, generierten wir außerdem MHCIIΔVE-CadherinΔVav1 M{\"a}use, bei welchen eine Antigenpr{\"a}sentation, weder im endothelialen noch im h{\"a}matopoetischen Kompartiment m{\"o}glich war. Lymphknoten-Stromazellen von MHCIIΔVE-CadherinΔVav1 M{\"a}usen waren nicht in der Lage, alloreaktive CD4+ T-Zellen in einer gemischten Lymphozytenreaktion zu aktivieren. Insgesamt konnten wir zum ersten Mal beweisen, dass die MHC-Klassse II auf den Lymphknoten-Stromazellen eine entscheidende Rolle bei der Modulation allogener CD4+ T-Zellen in der Initiations- und schließlich in der Effektorphase der Graft-versus-Host-Disease spielt.}, subject = {Transplantat-Wirt-Reaktion}, language = {en} } @techreport{GrunewaldKlockmannvonSchenketal.2024, type = {Working Paper}, author = {Grunewald, Andreas and Klockmann, Victor and von Schenk, Alicia and von Siemens, Ferdinand A.}, title = {Are Biases Contagious? The Influence of Communication on Motivated Beliefs}, doi = {10.25972/OPUS-34893}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348936}, pages = {1-38}, year = {2024}, abstract = {This paper examines the potential reinforcement of motivated beliefs when individuals with identical biases communicate. We propose a controlled online experiment that allows to manipulate belief biases and the communication environment. We find that communication, even among like-minded individuals, diminishes motivated beliefs if it takes place in an environment without previously declared external opinions. In the presence of external plural opinions, however, communication does not reduce but rather aggravates motivated beliefs. Our results indicate a potential drawback of the plurality of opinions - it may create communication environments wherein motivated beliefs not only persist but also become contagious within social networks.}, subject = {Bias}, language = {en} } @phdthesis{Hanio2024, author = {Hanio, Simon}, title = {The impact of bile on intestinal permeability of drug substances}, doi = {10.25972/OPUS-34890}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348906}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Most medicines are taken orally. To enter the systemic circulation, they dissolve in the intestinal fluid, cross the epithelial barrier, and pass through the liver. Intestinal absorption is driven by the unique features of the gastrointestinal tract, including the bile colloids formed in the lumen and the mucus layer covering the intestinal epithelium. Neglecting this multifaceted environment can lead to poor drug development decisions, especially for poorly water-soluble drugs that interact with bile and mucus. However, there is a lack of a rationale nexus of molecular interactions between oral medicines and gastrointestinal components with drug bioavailability. Against this background, this thesis aims to develop biopharmaceutical strategies to optimize the presentation of oral therapeutics to the intestinal epithelial barrier. In Chapter 1, the dynamics of bile colloids upon solubilization of the poorly-water soluble drug Perphenazine was studied. Perphenazine impacted molecular arrangement, structure, binding thermodynamics, and induced a morphological transition from vesicles to worm-like micelles. Despite these dynamics, the bile colloids ensured stable relative amounts of free drug substance. The chapter was published in Langmuir. Chapter 2 examined the impact of pharmaceutical polymeric excipients on bile-mediated drug solubilization. Perphenazine and Imatinib were introduced as model compounds interacting with bile, whereas Metoprolol did not. Some polymers altered the arrangement and geometry of bile colloids, thereby affecting the molecularly soluble amount of those drugs interacting with bile. These insights into the bile-drug-excipient interplay provide a blueprint to optimizing formulations leveraging bile solubilization. The chapter was published in Journal of Controlled Release. Chapter 3 deals with the impact of bile on porcine intestinal mucus. Mucus exposed to bile solution changed transiently, it stiffened, and the overall diffusion rate increased. The bile-induced changes eased the transport of the bile-interacting drug substance Fluphenazine, whereas Metoprolol was unaffected. This dichotomous pattern was linked to bioavailability in rats and generalized based on two previously published data sets. The outcomes point to a bile-mucus interaction relevant to drug delivery. The chapter is submitted. The Appendix provides a guide for biopharmaceutical characterization of drug substances by nuclear magnetic resonance spectroscopy aiming at establishing a predictive algorithm. In summary, this thesis deciphers bile-driven mechanisms shaping intestinal drug absorption. Based on these molecular insights, pharmaceuticals can be developed along a biopharmaceutical optimization, ultimately leading to better oral drugs of tomorrow.}, subject = {Solubilisation}, language = {en} } @phdthesis{SchukraftgebScheffler2024, author = {Schukraft [geb. Scheffler], Nina}, title = {Integrated defensive states and their neuronal correlates in the Periaqueductal Gray}, doi = {10.25972/OPUS-34745}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347458}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In the face of threat, animals react with a defensive reaction to avoid or reduce harm. This defensive reaction encompasses apart from behavioral changes also physiological, analgetic, and endocrine adaptations. Nonetheless, most animal studies on fear and anxiety are based on behavioral observations only, disregarding other aspects of the defensive reaction, or integrating their inter-related dynamics only insufficiently. The first part of this thesis aimed in characterizing patterned associations of behavioral and physiological responses, termed integrated defensive states. Analyzing cardiac and behavioral responses in mice undergoing multiple fear and anxiety paradigms revealed a complex and dynamic interaction of those readouts on both, short and long timescales. Microstates, stereotypical combinations of i.e. freezing and decelerating heart rates, are short-lasting and were, in turn, shown to be influenced by slow acting macrostate changes. One of those higher order macrostates, called `rigidity`, was defined as a latent process that constrains the range of momentary displayed heart rate values. Furthermore, integrated defensive states were found to be highly dependent on the cue and the context the animals are confronted with. Importantly, same behavioral observations, i.e. freezing, were associated with distinct cardiac responses, highlighting the importance of multivariate analysis of integrated defensive states. Defensive states are orchestrated by the brain, which has evolved evolutionary conserved survival circuits. A central brain area of these circuits is the periaqueductal gray (PAG) in the midbrain. It plays a pivotal role in mediating defensive states, as it receives signals about external and internal information from multiple brain regions and sends information to both, higher order brain areas as well as to the brainstem ultimately causing the execution of threat responses. In the second part of this thesis, different neuronal circuit elements in the PAG were optically manipulated in order to gain mechanistic insight into the defense network in the brain underlying the previously delineated cardio-behavioral defensive states. Optical activation of glutamatergic PAG neurons evoked heterogeneous, light-intensity dependent responses. However, a further molecular restriction of the glutamatergic neuronal population targeting only Chx10+ neurons, led to a cardio-behavioral state that resembled spontaneous freezing-bradycardia bouts. In summary, this thesis presents a multivariate description of defensive states, which includes the complex interaction of cardiac and behavioral responses on different timescales and, furthermore, functionally dissects different excitatory and inhibitory PAG circuit elements mediating these defensive states.}, subject = {Perianova, Irina}, language = {en} } @phdthesis{Rumpel2024, author = {Rumpel, Matthias}, title = {Development of Components for Solid-State Batteries and their Characterization}, doi = {10.25972/OPUS-34715}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347154}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {This Ph.D. thesis has addressed several main issues in current ASSB research within four studies. Ceramic ASSBs are meant to enable the implementation of Li-metal anodes and high voltage cathode materials, which would increase energy density, power density, life time as well as safety aspects in comparison with commercially available liquid electrolyte LiBs. In this thesis, several scientific questions arising on the cathode side of ASSBs have been focused on. With respect to the target system of a ternary composite bulk cathode consisting of ceramic active material, ceramic SSE and an electrically conductive component, studies about the thermal stabilities of these components and their impact on the electrochemical performance have been conducted. Particulate bulk cathode composites have to fulfil electrochemical, chemical, mechanical and structural requirements in order to compete with commercial LiBs. Particularly, the production process requires high-temperature sintering to obtain firmly bonded contacts in order to maximize the electrochemically active area, charge transfer and ionic conduction. However, interdiffusion, intermixing and decomposition of the initial components during sintering result in low-performing ASSBs so far. These side reactions during high-temperature treatment have been investigated in order to gain a better understanding of these mechanisms and to enable a better controlling of the manufacturing process as well as to simplify the choice of material combinations. The first two parts of this thesis deal with the thermal stability of the ceramic SSE LATP in combination with various active materials and with the validation of a probable improvement of the sintering process due to liquid phase sintering of LATP by adding Li3PO4. In the third and fourth parts, the impact of interdiffusion, intermixing and decomposition on the electrochemical performance of TF-SSBs based on the active material LMO and the ceramic SSE Ga-LLZO has been investigated.}, subject = {Elektrochemie}, language = {en} } @phdthesis{Janz2024, author = {Janz, Anna}, title = {Human induced pluripotent stem cells (iPSCs) in inherited cardiomyopathies: Generation and characterization of an iPSC-derived cardiomyocyte model system of dilated cardiomyopathy with ataxia (DCMA)}, doi = {10.25972/OPUS-24096}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240966}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The emergence of human induced pluripotent stem cells (iPSCs) and the rise of the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) gene editing technology innovated the research platform for scientists based on living human pluripotent cells. The revolutionary combination of both Nobel Prize-honored techniques enables direct disease modeling especially for research focused on genetic diseases. To allow the study on mutation-associated pathomechanisms, we established robust human in vitro systems of three inherited cardiomyopathies: arrhythmogenic cardiomyopathy (ACM), dilated cardiomyopathy with juvenile cataract (DCMJC) and dilated cardiomyopathy with ataxia (DCMA). Sendai virus vectors encoding OCT3/4, SOX2, KLF4, and c-MYC were used to reprogram human healthy control or mutation-bearing dermal fibroblasts from patients to an embryonic state thereby allowing the robust and efficient generation of in total five transgene-free iPSC lines. The nucleofection-mediated CRISPR/Cas9 plasmid delivery in healthy control iPSCs enabled precise and efficient genome editing by mutating the respective disease genes to create isogenic mutant control iPSCs. Here, a PKP2 knock-out and a DSG2 knock-out iPSC line were established to serve as a model of ACM. Moreover, a DNAJC19 C-terminal truncated variant (DNAJC19tv) was established to mimic a splice acceptor site mutation in DNAJC19 of two patients with the potential of recapitulating DCMA-associated phenotypes. In total eight self-generated iPSC lines were assessed matching internationally defined quality control criteria. The cells retained their ability to differentiate into cells of all three germ layers in vitro and maintained a stable karyotype. All iPSC lines exhibited a typical stem cell-like morphology as well as expression of characteristic pluripotency markers with high population purities, thus validating the further usage of all iPSC lines in in vitro systems of ACM, DCMA and DCMJC. Furthermore, cardiac-specific disease mechanisms underlying DCMA were investigated using in vitro generated iPSC-derived cardiomyocytes (iPSC-CMs). DCMA is an autosomal recessive disorder characterized by life threatening early onset cardiomyopathy associated with a metabolic syndrome. Causal mutations were identified in the DNAJC19 gene encoding an inner mitochondrial membrane (IMM) protein with a presumed function in mitochondrial biogenesis and cardiolipin (CL) remodeling. In total, two DCMA patient-derived iPSC lines (DCMAP1, DCMAP2) of siblings with discordant cardiac phenotypes, a third isogenic mutant control iPSC line (DNAJC19tv) as well as two control lines (NC6M and NC47F) were directed towards the cardiovascular lineage upon response to extracellular specification cues. The monolayer cardiac differentiation approach was successfully adapted for all five iPSC lines and optimized towards ventricular subtype identity, higher population purities and enhanced maturity states to fulfill all DCMA-specific requirements prior to phenotypic investigations. To provide a solid basis for the study of DCMA, the combination of lactate-based metabolic enrichment, magnetic-activated cell sorting, mattress-based cultivation and prolonged cultivation time was performed in an approach-dependent manner. The application of the designated strategies was sufficient to ensure adult-like characteristics, which included at least 60-day-old iPSC-CMs. Therefore, the novel human DCMA platform was established to enable the study of the pathogenesis underlying DCMA with respect to structural, morphological and functional changes. The disease-associated protein, DNAJC19, is constituent of the TIM23 import machinery and can directly interact with PHB2, a component of the membrane bound hetero-oligomeric prohibitin ring complexes that are crucial for phospholipid and protein clustering in the IMM. DNAJC19 mutations were predicted to cause a loss of the DnaJ interaction domain, which was confirmed by loss of full-length DNAJC19 protein in all mutant cell lines. The subcellular investigation of DNAJC19 demonstrated a nuclear restriction in mutant iPSC-CMs. The loss of DNAJC19 co-localization with mitochondrial structures was accompanied by enhanced fragmentation, an overall reduction of mitochondrial mass and smaller cardiomyocytes. Ultrastructural analysis yielded decreased mitochondria sizes and abnormal cristae providing a link to defects in mitochondrial biogenesis and CL remodeling. Preliminary data on CL profiles revealed longer acyl chains and a more unsaturated acyl chain composition highlighting abnormities in the phospholipid maturation in DCMA. However, the assessment of mitochondrial function in iPSCs and dermal fibroblasts revealed an overall higher oxygen consumption that was even more enhanced in iPSC-CMs when comparing all three mutants to healthy controls. Excess oxygen consumption rates indicated a higher electron transport chain (ETC) activity to meet cellular ATP demands that probably result from proton leakage or the decoupling of the ETC complexes provoked by abnormal CL embedding in the IMM. Moreover, in particular iPSC-CMs presented increased extracellular acidification rates that indicated a shift towards the utilization of other substrates than fatty acids, such as glucose, pyruvate or glutamine. The examination of metabolic features via double radioactive tracer uptakes (18F-FDG, 125I-BMIPP) displayed significantly decreased fatty acid uptake in all mutants that was accompanied by increased glucose uptake in one patient cell line only, underlining a highly dynamic preference of substrates between mutant iPSC-CMs. To connect molecular changes directly to physiological processes, insights on calcium kinetics, contractility and arrhythmic potential were assessed and unraveled significantly increased beating frequencies, elevated diastolic calcium concentrations and a shared trend towards reduced cell shortenings in all mutant cell lines basally and upon isoproterenol stimulation. Extended speed of recovery was seen in all mutant iPSC-CMs but most striking in one patient-derived iPSC-CM model, that additionally showed significantly prolonged relaxation times. The investigations of calcium transient shapes pointed towards enhanced arrhythmic features in mutant cells comprised by both the occurrence of DADs/EADs and fibrillation-like events with discordant preferences. Taken together, new insights into a novel in vitro model system of DCMA were gained to study a genetically determined cardiomyopathy in a patient-specific manner upon incorporation of an isogenic mutant control. Based on our results, we suggest that loss of full-length DNAJC19 impedes PHB2-complex stabilization within the IMM, thus hindering PHB-rings from building IMM-specific phospholipid clusters. These clusters are essential to enable normal CL remodeling during cristae morphogenesis. Disturbed cristae and mitochondrial fragmentation were observed and refer to an essential role of DNAJC19 in mitochondrial morphogenesis and biogenesis. Alterations in mitochondrial morphology are generally linked to reduced ATP yields and aberrant reactive oxygen species production thereby having fundamental downstream effects on the cardiomyocytes` functionality. DCMA-associated cellular dysfunctions were in particular manifested in excess oxygen consumption, altered substrate utilization and abnormal calcium kinetics. The summarized data highlight the usage of human iPSC-derived CMs as a powerful tool to recapitulate DCMA-associated phenotypes that offers an unique potential to identify therapeutic strategies in order to reverse the pathological process and to pave the way towards clinical applications for a personalized therapy of DCMA in the future.}, subject = {Induzierte pluripotente Stammzelle}, language = {en} } @phdthesis{Hock2024, author = {Hock, Michael}, title = {Methods for Homogenization of Spatio-Temporal B\(_0\) Magnetic Field Variations in Cardiac MRI at Ultra-High Field Strength}, doi = {10.25972/OPUS-34821}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348213}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Cardiovascular disease is one of the leading causes of death worldwide and, so far, echocardiography, nuclear cardiology, and catheterization are the gold standard techniques used for its detection. Cardiac magnetic resonance (CMR) can replace the invasive imaging modalities and provide a "one-stop shop" characterization of the cardiovascular system by measuring myocardial tissue structure, function and perfusion of the heart, as well as anatomy of and flow in the coronary arteries. In contrast to standard clinical magnetic resonance imaging (MRI) scanners, which are often operated at a field strength of 1.5 or 3 Tesla (T), a higher resolution and subsequent cardiac parameter quantification could potentially be achieved at ultra-high field, i.e., 7 T and above. Unique insights into the pathophysiology of the heart are expected from ultra-high field MRI, which offers enhanced image quality in combination with novel contrast mechanisms, but suffers from spatio-temporal B0 magnetic field variations. Due to the resulting spatial misregistration and intra-voxel dephasing, these B0-field inhomogeneities generate a variety of undesired image artifacts, e.g., artificial image deformation. The resulting macroscopic field gradients lead to signal loss, because the effective transverse relaxation time T2* is shortened. This affects the accuracy of T2* measurements, which are essential for myocardial tissue characterization. When steady state free precession-based pulse sequences are employed for image acquisition, certain off-resonance frequencies cause signal voids. These banding artifacts complicate the proper marking of the myocardium and, subsequently, systematic errors in cardiac function measurements are inevitable. Clinical MR scanners are equipped with basic shim systems to correct for occurring B0-field inhomogeneities and resulting image artifacts, however, these are not sufficient for the advanced measurement techniques employed for ultra-high field MRI of the heart. Therefore, this work focused on the development of advanced B0 shimming strategies for CMR imaging applications to correct the spatio-temporal B0 field variations present in the human heart at 7 T. A novel cardiac phase-specific shimming (CPSS) technique was set up, which featured a triggered B0 map acquisition, anatomy-matched selection of the shim-region-of-interest (SROI), and calibration-based B0 field modeling. The influence of technical limitations on the overall spherical harmonics (SH) shim was analyzed. Moreover, benefits as well as pitfalls of dynamic shimming were debated in this study. An advanced B0 shimming strategy was set up and applied in vivo, which was the first implementation of a heart-specific shimming approach in human UHF MRI at the time. The spatial B0-field patterns which were measured in the heart throughout this study contained localized spots of strong inhomogeneities. They fluctuated over the cardiac cycle in both size and strength, and were ideally addressed using anatomy-matched SROIs. Creating a correcting magnetic field with one shim coil, however, generated eddy currents in the surrounding conducting structures and a resulting additional, unintended magnetic field. Taking these shim-to-shim interactions into account via calibration, it was demonstrated for the first time that the non-standard 3rd-order SH terms enhanced B0-field homogeneity in the human heart. However, they were attended by challenges for the shim system hardware employed in the presented work, which was indicated by the currents required to generate the optimal 3rd-order SH terms exceeding the dynamic range of the corresponding shim coils. To facilitate dynamic shimming updated over the cardiac cycle for cine imaging, the benefit of adjusting the oscillating CPSS currents was found to be vital. The first in vivo application of the novel advanced B0 shimming strategy mostly matched the simulations. The presented technical developments are a basic requirement to quantitative and functional CMR imaging of the human heart at 7 T. They pave the way for numerous clinical studies about cardiac diseases, and continuative research on dedicated cardiac B0 shimming, e.g., adapted passive shimming and multi-coil technologies.}, subject = {Kernspintomografie}, language = {en} } @phdthesis{SpaethgebLutz2024, author = {Sp{\"a}th [geb. Lutz], Johanna}, title = {Oberfl{\"a}chenfunktionalisierte Gold- und Silbernanopartikel auf Basis von Thioether-Poly(glycidol) f{\"u}r potenzielle biomedizinische Anwendungen - Auswirkungen auf Stabilit{\"a}t, Proteinkoronabildung und Biodistribution}, doi = {10.25972/OPUS-35066}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350662}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Based on previous results showing that thioether modification of gold nanoparticles (AuNPs), especially coating with a multivalent system, yielded in excellent colloidal stability, the first aim of this thesis was to prove whether functionalization of silver nanoparticles (AgNPs) with thioether also has a comparable or even enhanced stabilization efficacy compared with the gold standard of coating with thiols and, particularly, whether the multivalency of polymers leads to stable AgNPs conjugates. Herein, AgNPs coated with mono- and multivalent thiol- and thioether polymers were prepared to systematically investigate the adsorption kinetics onto the silver surface as well as the colloidal stability after exposure to different conditions relevant for biomedical application. Although the thioether-polymers showed a slower immobilization onto AgNPs, same or mostly even better stabilization was exhibited than for the thiol analogs. As multivalent thioether-poly(glycidol) (PG) is already proven as a promising candidate for AuNP modification and stabilization, the second aim of this thesis was to examine the stealth behavior of thioether-PG, side-chain functionalized with various hydrophobic (alkyl and cholesteryl) units, to gain a deeper understanding of AuNP surface functionalization in terms of protein adsorption and their subsequent cellular uptake by human monocyte-derived macrophages. For this purpose, citrate-stabilized AuNPs were modified with the amphiphilic polymers by ligand exchange reaction, followed by incubation in human serum. The various surface amphiphilicities affected protein adsorption to a certain extent, with less hydrophobic particle layers leading to a more inhibited protein binding. Especially AuNPs functionalized with PG carrying the longest alkyl chain showed differences in the protein corona composition compared to the other polymer-coated NPs. In addition, PGylation, and especially prior serum incubation, of the NPs exhibited reduced macrophage internalization. As the use of mammals for in vivo experiments faces various challenges including increasing regulatory hurdles and costs, the third aim of this thesis was to validate larvae of the domestic silkworm Bombyx mori as an alternative invertebrate model for preliminary in vivo research, using AuNPs with various surface chemistry (one PEG-based modification and three PG-coatings with slightly hydrophobic functionalization, as well as positively and negatively charges) for studying their biodistribution and elimination. 6 h and 24 h after intra-hemolymph injection the Au content in different organ compartments was measured with ICP-MS, showing that positively charged particles appeared to be eliminated most rapidly through the midgut, while AuNPs modified with PEG, alkyl-functionalized PG and negatively charged PG exhibited long-term bioavailability in the silkworm body.}, subject = {Nanopartikel}, language = {en} } @phdthesis{Kobs2024, author = {Kobs, Konstantin}, title = {Think outside the Black Box: Model-Agnostic Deep Learning with Domain Knowledge}, doi = {10.25972/OPUS-34968}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349689}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Deep Learning (DL) models are trained on a downstream task by feeding (potentially preprocessed) input data through a trainable Neural Network (NN) and updating its parameters to minimize the loss function between the predicted and the desired output. While this general framework has mainly remained unchanged over the years, the architectures of the trainable models have greatly evolved. Even though it is undoubtedly important to choose the right architecture, we argue that it is also beneficial to develop methods that address other components of the training process. We hypothesize that utilizing domain knowledge can be helpful to improve DL models in terms of performance and/or efficiency. Such model-agnostic methods can be applied to any existing or future architecture. Furthermore, the black box nature of DL models motivates the development of techniques to understand their inner workings. Considering the rapid advancement of DL architectures, it is again crucial to develop model-agnostic methods. In this thesis, we explore six principles that incorporate domain knowledge to understand or improve models. They are applied either on the input or output side of the trainable model. Each principle is applied to at least two DL tasks, leading to task-specific implementations. To understand DL models, we propose to use Generated Input Data coming from a controllable generation process requiring knowledge about the data properties. This way, we can understand the model's behavior by analyzing how it changes when one specific high-level input feature changes in the generated data. On the output side, Gradient-Based Attribution methods create a gradient at the end of the NN and then propagate it back to the input, indicating which low-level input features have a large influence on the model's prediction. The resulting input features can be interpreted by humans using domain knowledge. To improve the trainable model in terms of downstream performance, data and compute efficiency, or robustness to unwanted features, we explore principles that each address one of the training components besides the trainable model. Input Masking and Augmentation directly modifies the training input data, integrating knowledge about the data and its impact on the model's output. We also explore the use of Feature Extraction using Pretrained Multimodal Models which can be seen as a beneficial preprocessing step to extract useful features. When no training data is available for the downstream task, using such features and domain knowledge expressed in other modalities can result in a Zero-Shot Learning (ZSL) setting, completely eliminating the trainable model. The Weak Label Generation principle produces new desired outputs using knowledge about the labels, giving either a good pretraining or even exclusive training dataset to solve the downstream task. Finally, improving and choosing the right Loss Function is another principle we explore in this thesis. Here, we enrich existing loss functions with knowledge about label interactions or utilize and combine multiple task-specific loss functions in a multitask setting. We apply the principles to classification, regression, and representation tasks as well as to image and text modalities. We propose, apply, and evaluate existing and novel methods to understand and improve the model. Overall, this thesis introduces and evaluates methods that complement the development and choice of DL model architectures.}, subject = {Deep learning}, language = {en} } @phdthesis{BakariSoale2024, author = {Bakari Soale, Majeed}, title = {Regulation of the Variant Surface Glycoprotein (VSG) Expression and Characterisation of the Nucleolar DExD/H box Protein Hel66 in \(Trypanosoma\) \(brucei\)}, doi = {10.25972/OPUS-25809}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258090}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The variant surface glycoprotein (VSG) of African trypanosomes plays an essential role in protecting the parasites from host immune factors. These trypanosomes undergo antigenic variation resulting in the expression of a single VSG isoform out of a repertoire of around 2000 genes. The molecular mechanism central to the expression and regulation of the VSG is however not fully understood. Gene expression in trypanosomes is unusual due to the absence of typical RNA polymerase II promoters and the polycistronic transcription of genes. The regulation of gene expression is therefore mainly post-transcriptional. Regulatory sequences, mostly present in the 3´ UTRs, often serve as key elements in the modulation of the levels of individual mRNAs. In T. brucei VSG genes, a 100 \% conserved 16mer motif within the 3´ UTR has been shown to modulate the stability of VSG transcripts and hence their expression. As a stability-associated sequence element, the absence of nucleotide substitutions in the motif is however unusual. It was therefore hypothesised that the motif is involved in other essential roles/processes besides stability of the VSG transcripts. In this study, it was demonstrated that the 100 \% conservation of the 16mer motif is not essential for cell viability or for the maintenance of functional VSG protein levels. It was further shown that the intact motif in the active VSG 3´ UTR is neither required to promote VSG silencing during switching nor is it needed during differentiation from bloodstream forms to procyclic forms. Crosstalk between the VSG and procyclin genes during differentiation to the insect vector stage is also unaffected in cells with a mutated 16mer motif. Ectopic overexpression of a second VSG however requires the intact motif to trigger silencing and exchange of the active VSG, suggesting a role for the motif in transcriptional VSG switching. The 16mer motif therefore plays a dual role in VSG in situ switching and stability of VSG transcripts. The additional role of the 16mer in the essential process of antigenic variation appears to be the driving force for the 100 \% conservation of this RNA motif. A screen aimed at identifying candidate RNA-binding proteins interacting with the 16mer motif, led to the identification of a DExD/H box protein, Hel66. Although the protein did not appear to have a direct link to the 16mer regulation of VSG expression, the DExD/H family of proteins are important players in the process of ribosome biogenesis. This process is relatively understudied in trypanosomes and so this candidate was singled out for detailed characterisation, given that the 16mer story had reached a natural end point. Ribosome biogenesis is a major cellular process in eukaryotes involving ribosomal RNA, ribosomal proteins and several non-ribosomal trans-acting protein factors. The DExD/H box proteins are the most important trans-acting protein factors involved in the biosynthesis of ribosomes. Several DExD/H box proteins have been directly implicated in this process in yeast. In trypanosomes, very few of this family of proteins have been characterised and therefore little is known about the specific roles they play in RNA metabolism. Here, it was shown that Hel66 is involved in rRNA processing during ribosome biogenesis. Hel66 localises to the nucleolus and depleting the protein led to a severe growth defect. Loss of the protein also resulted in a reduced rate of global translation and accumulation of rRNA processing intermediates of both the small and large ribosomal subunits. Hel66 is therefore an essential nucleolar DExD/H protein involved in rRNA processing during ribosome biogenesis. As very few protein factors involved in the processing of rRNAs have been described in trypanosomes, this finding represents an important platform for future investigation of this topic.}, subject = {Trypanosoma brucei}, language = {en} } @phdthesis{Massih2024, author = {Massih, Bita}, title = {Human stem cell-based models to analyze the pathophysiology of motor neuron diseases}, publisher = {Frontiers in Cell and Developmental Biology}, doi = {10.25972/OPUS-34637}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346374}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Motor neuron diseases (MNDs) encompass a variety of clinically and genetically heterogeneous disorders, which lead to the degeneration of motor neurons (MNs) and impaired motor functions. MNs coordinate and control movement by transmitting their signal to a target muscle cell. The synaptic endings of the MN axon and the contact site of the muscle cell thereby form the presynaptic and postsynaptic structures of the neuromuscular junction (NMJ). In MNDs, synaptic dysfunction and synapse elimination precede MN loss suggesting that the NMJ is an early target in the pathophysiological cascade leading to MN death. In this study, we established new experimental strategies to analyze human MNDs by patient derived induced pluripotent stem cells (iPSCs) and investigated pathophysiological mechanisms in two different MNDs. To study human MNDs, specialized cell culture systems that enable the connection of MNs to their target muscle cells are required to allow the formation of NMJs. In the first part of this study, we established and validated a human neuromuscular co-culture system consisting of iPSC derived MNs and 3D skeletal muscle tissue derived from myoblasts. We generated 3D muscle tissue by culturing primary myoblasts in a defined extracellular matrix in self-microfabricated silicone dishes that support the 3D tissue formation. Subsequently, iPSCs from healthy donors and iPSCs from patients with the progressive MND Amyotrophic Lateral Sclerosis (ALS) were differentiated into MNs and used for 3D neuromuscular co-cultures. Using a combination of immunohistochemistry, calcium imaging, and pharmacological stimulations, we characterized and confirmed the functionality of the 3D muscle tissue and the 3D neuromuscular co-cultures. Finally, we applied this system as an in vitro model to study the pathophysiology of ALS and found a decrease in neuromuscular coupling, muscle contraction, and axonal outgrowth in co-cultures with MNs harboring ALS-linked superoxide dismutase 1 (SOD1) mutation. In summary, this co-culture system presents a human model for MNDs that can recapitulate aspects of ALS pathophysiology. In the second part of this study, we identified an impaired unconventional protein secretion (UPS) of Sod1 as pathological mechanisms in Pleckstrin homology domain-containing family G member 5 (Plekhg5)-associated MND. Sod1 is a leaderless cytosolic protein which is secreted in an autophagy-dependent manner. We found that Plekhg5 depletion in primary MNs and NSC34 cells leads to an impaired secretion of wildtype Sod1, indicating that Plekhg5 drives the UPS of Sod1 in vitro. By interfering with different steps during the biogenesis of autophagosomes, we could show that Plekhg5-regulated Sod1 secretion is determined by autophagy. To analyze our findings in a clinically more relevant model we utilized human iPSC MNs from healthy donors and ALS patients with SOD1 mutations. We observed reduced SOD1 secretion in ALS MNs which coincides with reduced protein expression of PLEKHG5 compared to healthy and isogenic control MNs. To confirm this correlation, we depleted PLEKHG5 in control MNs and found reduced extracellular SOD1 levels, implying that SOD1 secretion depends on PLEKHG5. In summary, we found that Plekh5 regulates the UPS of Sod1 in mouse and human MNs and that Sod1 secretion occurs in an autophagy dependent manner. Our data shows an unreported mechanistic link between two MND-associated proteins.}, subject = {Tissue Engineering}, language = {en} } @phdthesis{Daeullary2024, author = {D{\"a}ullary, Thomas}, title = {Establishment of an infection model of the human intestinal epithelium to study host and pathogen determinants during the \(Salmonella\) Typhimurium infection process}, doi = {10.25972/OPUS-31154}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311548}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {According to the WHO, foodborne derived enteric infections are a global disease burden and often manifest in diseases that can potentially reach life threatening levels, especially in developing countries. These diseases are caused by a variety of enteric pathogens and affect the gastrointestinal tract, from the gastric to the intestinal to the rectal tissue. Although the complex mucosal structure of these organs is usually well prepared to defend the body against harmful agents, specialised pathogens such as Salmonella enterica can overcome the intestinal defence mechanism. After ingestion, Salmonella are capable of colonising the gut and establishing their proliferative niche, thereby leading to inflammatory processes and tissue damage of the host epithelium. In order to understand these processes, the scientific community in the last decades mostly used cell line based in vitro approaches or in vivo animal studies. Although these approaches provide fundamental insights into the interactions between bacteria and host cells, they have limited applicability to human pathology. Therefore, tissue engineered primary based approaches are important for modern infection research. They exhibit the human complexity better than traditional cell lines and can mimic human-obligate processes in contrast to animal studies. Therefore, in this study a tissue engineered human primary model of the small intestinal epithelium was established for the application of enteric infection research with the exemplary pathogen Salmonella Typhimurium. To this purpose, adult stem cell derived intestinal organoids were used as a primary human cell source to generate monolayers on biological or synthetic scaffolds in a Transwell®-like setting. These tissue models of the intestinal epithelium were examined for their comparability to the native tissue in terms of morphology, morphometry and barrier function. Further, the gene expression profiles of organotypical mucins, tight junction-associated proteins and claudins were investigated. Overall, the biological scaffold-based tissue models showed higher similarity to the native tissue - among others in morphometry and polarisation. Therefore, these models were further characterised on cellular and structural level. Ultrastructural analysis demonstrated the establishment of characteristic microvilli and tight-junction connections between individual epithelial cells. Furthermore, the expression pattern of typical intestinal epithelial protein was addressed and showed in vivo-like localisation. Interested in the cell type composition, single cell transcriptomic profiling revealed distinct cell types including proliferative cells and stem cells, progenitors, cellular entities of the absorptive lineage, Enterocytes and Microfold-like cells. Cells of the secretory lineage were also annotated, but without distinct canonical gene expression patterns. With the organotypical polarisation, protein expression, structural features and the heterogeneous cell composition including the rare Microfold-like cells, the biological scaffold-based tissue model of the intestinal epithelium demonstrates key requisites needed for infection studies with Salmonella. In a second part of this study, a suitable infection protocol of the epithelial tissue model with Salmonella Typhimurium was established, followed by the examination of key features of the infection process. Salmonella adhered to the epithelial microvilli and induced typical membrane ruffling during invasion; interestingly the individual steps of invasion could be observed. After invasion, time course analysis showed that Salmonella resided and proliferated intracellularly, while simultaneously migrating from the apical to the basolateral side of the infected cell. Furthermore, the bacterial morphology changed to a filamentous phenotype; especially when the models have been analysed at late time points after infection. The epithelial cells on the other side released the cytokines Interleukin 8 and Tumour Necrosis Factor α upon bacterial infection in a time-dependent manner. Taken together, Salmonella infection of the intestinal epithelial tissue model recapitulates important steps of the infection process as described in the literature, and hence demonstrates a valid in vitro platform for the investigation of the Salmonella infection process in the human context. During the infection process, intracellular Salmonella populations varied in their bacterial number, which could be attributed to increased intracellular proliferation and demonstrated thereby a heterogeneous behaviour of Salmonella in individual cells. Furthermore, by the application of single cell transcriptomic profiling, the upregulation of Olfactomedin-4 (OLFM4) gene expression was detected; OLFM4 is a protein involved in various functions including cell immunity as well as proliferating signalling pathways and is often used as intestinal stem cell marker. This OLFM4 upregulation was time-dependent, restricted to Salmonella infected cells and seemed to increase with bacterial mass. Investigating the OLFM4 regulatory mechanism, nuclear factor κB induced upregulation could be excluded, whereas inhibition of the Notch signalling led to a decrease of OLFM4 gene and protein expression. Furthermore, Notch inhibition resulted in decreased filamentous Salmonella formation. Taken together, by the use of the introduced primary epithelial tissue model, a heterogeneous intracellular bacterial behaviour was observed and a so far overlooked host cell response - the expression of OLFM4 by individual infected cells - could be identified; although Salmonella Typhimurium is one of the best-studied enteric pathogenic bacteria. This proves the applicability of the introduced tissue model in enteric infection research as well as the importance of new approaches in order to decipher host-pathogen interactions with higher relevance to the host.}, subject = {Salmonella typhimurium}, language = {en} } @phdthesis{Isasa2024, author = {Isasa, Emilie}, title = {Relationship between wood properties, drought-induced embolism and environmental preferences across temperate diffuse-porous broadleaved trees}, doi = {10.25972/OPUS-30356}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303562}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In the scope of climate warming and the increase in frequency and intensity of severe heat waves in Central Europe, identification of temperate tree species that are suited to cope with these environmental changes is gaining increasing importance. A number of tree physiological characteristics are associated with drought-stress resistance and survival following severe heat, but recent studies have shown the importance of plant hydraulic and anatomical traits for predicting drought-induced tree mortality, such as vessel diameter, and their potential to predict species distribution in a changing climate. A compilation of large global datasets is required to determine traits related to drought-induced embolism and test whether embolism resistance can be determined solely by anatomical traits. However, most measurements of plant hydraulic traits are labour-intense and prone to measurement artefacts. A fast, accurate and widely applicable technique is necessary for estimating xylem embolism resistance (e.g., water potential at 50\% loss of conductivity, P50), in order to improve forecasts of future forest changes. These traits and their combination must have evolved following the selective pressure of the environmental conditions in which each species occurs. Describing these environmental-trait relationships can be useful to assess potential responses to environmental change and mitigation strategies for tree species, as future warmer temperatures may be compounded by drier conditions.}, subject = {Pflanzen{\"o}kologie}, language = {en} } @phdthesis{Kibe2024, author = {Kibe, Anuja}, title = {Translational landscape and regulation of recoding in virus-infected cells}, doi = {10.25972/OPUS-31099}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310993}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {RNA viruses rely entirely on the host machinery for their protein synthesis and harbor non-canonical translation mechanisms, such as alternative initiation and programmed -1 ribosomal frameshifting (-1PRF), to suit their specific needs. On the other hand, host cells have developed a variety of defensive strategies to safeguard their translational apparatus and at times transiently shut down global translation. An infection can lead to substantial translational remodeling in cells and translational control is critical during antiviral response. Due to their sheer diversity, this control is likely unique to each RNA virus and the intricacies of post-transcriptional regulation are unclear in certain viral species. Here, we explored different aspects of translational regulation in virus-infected cells in detail. Using ribosome profiling, we extensively characterized the translational landscape in HIV-1 infected T cells, uncovering novel features of gene regulation in both host and virus. Additionally, we show that substantial pausing occurs prior to the frameshift site indicating complex regulatory mechanisms involving upstream viral RNA elements that can act as cis- regulators of frameshifting. We also characterized the mechanistic details of trans- modulation of frameshifting by host- and virus-encoded proteins. Host antiviral protein ZAP-S binds to the SARS-CoV-2 frameshift site and destabilizes the stimulatory structure, leading to frameshift inhibition. On the other hand, EMCV 2A protein stabilizes the viral frameshift site, thereby, activating EMCV frameshifting. While both proteins were shown to be antagonistic in their mechanism, they interact with the host translational machinery. Furthermore, we showed that frameshifting can be regulated not just by proteins, but also by small molecules. High-throughput screening of natural and synthetic compounds identified two potent frameshift inhibitors that also impeded viral replication, namely trichangion and compound 25. Together, this work largely enhances our understanding of gene regulation mechanisms in virus-infected cells and further validates the druggability of viral -1 PRF site.}, subject = {Zelle}, language = {en} } @phdthesis{Hoerner2024, author = {H{\"o}rner, Michaela}, title = {The role of inflammation in hereditary spastic paraplegia type 11}, doi = {10.25972/OPUS-30336}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303368}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Hereditary spastic paraplegias (HSPs) are genetically-determined, neurodegenerative disorders characterized by progressive weakness and spasticity of the lower limbs. Spastic paraplegia type 11 (SPG11) is a complicated form of HSP, which is caused by mutations in the SPG11 gene encoding spatacsin, a protein possibly involved in lysosomal reformation. Based on our previous studies demonstrating that secondary neuroinflammation can be a robust amplifier of various genetically-mediated diseases of both the central and peripheral nervous system, we here test the possibility that neuroinflammation may modify the disease outcome also in a mouse model for SPG11. Spg11-knockout (Spg11-/-) mice develop early walking pattern and behavioral abnormalities, at least partially reflecting motor, and behavioral changes typical for patients. Furthermore, we detected a progressive increase in axonal damage and axonal spheroid formation in the white and grey matter compartments of the central nervous system of Spg11-/- mice. This was accompanied by a concomitant substantial increase of secondary inflammation by cytotoxic CD8+ and CD4+ T-lymphocytes. We here provide evidence that disease-related changes can be ameliorated/delayed by the genetic deletion of the adaptive immune system. Accordingly, we provide evidence that repurposing clinically approved immunomodulators (fingolimod/FTY720 or teriflunomide), that are in use for treatment of multiple sclerosis (MS), also improve disease symptoms in mice, when administered in an early (before neural damage) or late (after/during neural damage) treatment regime. This work provides strong evidence that immunomodulation can be a therapeutic option for the still untreatable SPG11, including its typical neuropsychological features. This poses the question if inflammation is not only a disease amplifier in SPG11 but can act as a unifying factor also for other genetically mediated disorders of the CNS. If true, this may pave the way to therapeutic options in a wide range of still untreatable, primarily genetic, neurological disorders by repurposing approved immunomodulators.}, subject = {Entz{\"u}ndung}, language = {en} } @phdthesis{Loh2024, author = {Loh, Frank}, title = {Monitoring the Quality of Streaming and Internet of Things Applications}, edition = {korrigierte Version}, issn = {1432-8801}, doi = {10.25972/OPUS-35096}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350969}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The ongoing and evolving usage of networks presents two critical challenges for current and future networks that require attention: (1) the task of effectively managing the vast and continually increasing data traffic and (2) the need to address the substantial number of end devices resulting from the rapid adoption of the Internet of Things. Besides these challenges, there is a mandatory need for energy consumption reduction, a more efficient resource usage, and streamlined processes without losing service quality. We comprehensively address these efforts, tackling the monitoring and quality assessment of streaming applications, a leading contributor to the total Internet traffic, as well as conducting an exhaustive analysis of the network performance within a Long Range Wide Area Network (LoRaWAN), one of the rapidly emerging LPWAN solutions.}, subject = {Leistungsbewertung}, language = {en} } @phdthesis{Loh2024, author = {Loh, Frank}, title = {Monitoring the Quality of Streaming and Internet of Things Applications}, issn = {1432-8801}, doi = {10.25972/OPUS-34783}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347831}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The ongoing and evolving usage of networks presents two critical challenges for current and future networks that require attention: (1) the task of effectively managing the vast and continually increasing data traffic and (2) the need to address the substantial number of end devices resulting from the rapid adoption of the Internet of Things. Besides these challenges, there is a mandatory need for energy consumption reduction, a more efficient resource usage, and streamlined processes without losing service quality. We comprehensively address these efforts, tackling the monitoring and quality assessment of streaming applications, a leading contributor to the total Internet traffic, as well as conducting an exhaustive analysis of the network performance within a Long Range Wide Area Network (LoRaWAN), one of the rapidly emerging LPWAN solutions.}, subject = {Leistungsbewertung}, language = {en} } @phdthesis{KosergebKretzschmar2024, author = {Koser [geb. Kretzschmar], Charlotte Ursula}, title = {\(Mon\) \(Aprendisage\) - Midwifery Training at the H{\^o}tel-Dieu de Paris 1704}, doi = {10.25972/OPUS-34952}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349520}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {This thesis provides an edition and commentary of a manuscript discovered by Michael Stolberg in the archives of the central library in Zurich under the title "Mon aprendisage {\`a} l'H{\^o}tel Dieu de Paris 1704." (My apprenticeship at the H{\^o}tel-Dieu de Paris 1704). The manuscript contains records of a midwifery student at the H{\^o}tel-Dieu de Paris, an old hospital famous among others for its education in midwifery in the maternity ward. We read about managing different births, recipes for common remedies, direct questions answered by the ma{\^i}tresse sage-femme, the leading midwife at the H{\^o}tel-Dieu de Paris and more. Although other accounts exist of the maternity ward at the H{\^o}tel-Dieu de Paris, \(Mon\) \(Aprendisage\) is the first and only account from a midwife's perspective that gives more than just instructions on obstetrical techniques. It takes us into the day-to-day experience of a woman as she progressed through her training at the H{\^o}tel-Dieu.}, subject = {Hebamme}, language = {en} } @phdthesis{Krampert2024, author = {Krampert, Laura}, title = {Dynamics of cardiac neutrophil diversity in murine myocardial infarction}, doi = {10.25972/OPUS-34957}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349576}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {After myocardial infarction, an inflammatory response is induced characterized by a sterile inflammation, followed by a reparative phase in order to induce cardiac healing. Neutrophils are the first immune cells that enter the ischemic tissue. Neutrophils have various functions in the ischemic heart, such as phagocytosis, production of reactive oxygen species or release of granule components. These functions can not only directly damage cardiac tissue, but are also necessary for initiating reparative effects in post-ischemic healing, indicating a dual role of neutrophils in cardiac healing after infarction. In recent years, evidence has been growing that neutrophils show phenotypic and functional differences in distinct homeostatic and pathogenic settings. Preliminary data of my working group using single-cell RNA-sequencing revealed the time- dependent heterogeneity of neutrophils, with different populations showing distinct gene expression profiles in ischemic hearts of mice, including the time-dependent appearance of a SiglecFhigh neutrophil population. To better understand the dynamics of neutrophil heterogeneity in the ischemic heart, my work aimed to validate previous findings at the protein level, as well as to investigate whether the distinct neutrophil populations show functional differences. Furthermore, in vivo depletion experiments were performed in order to modulate circulating neutrophil levels. Hearts, blood, bone marrow and spleens were processed and analyzed from mice after 1 day and 3 days after the onset of cardiac ischemia and analyzed using flow cytometry. Results showed that the majority of cardiac neutrophils isolated at day 3 after myocardial infarction were SiglecFhigh, whereas nearly no SiglecFhigh neutrophils could be isolated from ischemic hearts at day 1 after myocardial infarction. No SiglecFhigh neutrophils could be found in the blood, spleen and bone marrow either after 1 day or 3 days after myocardial infarction, indicating that the SiglecFhigh state of neutrophils is unique to the ischemic cardiac tissue. When I compared SiglecFhigh and SiglecFlow neutrophils regarding their phagocytosis activity and ROS production, SiglecFhigh neutrophils showed a higher phagocytosis ability than their SiglecFlow counterparts, as well as higher ROS production capacity. In vivo depletion experiments could not achieve successful and efficient depletion of cardiac neutrophils either 1 day or 3 days after myocardial infarction, but led to a shift of a higher percentage of SiglecFhigh expressing neutrophils in the depletion group. Bone marrow neutrophil levels only showed partial depletion at day 3 after MI. Regarding blood neutrophils, depletion efficiently reduced circulating neutrophils at both time points, 1 and 3 days after MI. To summarize, this work showed the time-dependent presence of different neutrophil states in the ischemic heart. The main population of neutrophils isolated 3 days after MI showed a high expression of SiglecF, a unique state that could not be detected at different time points or other organs. These SiglecFhigh neutrophils showed functional differences regarding their phagocytosis ability and ROS production. Further investigation is needed to reveal what role these SiglecFhigh neutrophils could play within the ischemic heart. To better target neutrophil depletion in vivo, more efficient or different anti-neutrophil strategies are needed.}, subject = {Neutrophiler Granulozyt}, language = {en} } @phdthesis{Aido2024, author = {Aido, Ahmed}, title = {Development of anti-TNF antibody-gold nanoparticles (anti-TNF-AuNPs)}, doi = {10.25972/OPUS-34921}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349212}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Gold nanoparticles of diameter ca. 60 nm have been synthesized based on Turkevich and Frens protocols. We have demonstrated that the carboxyl-modified gold nanoparticles can be coupled covalently with antibodies (Ab) of interest using the EDC/NHS coupling procedure. Binding studies with Ab-grafted AuNPs and GpL fusion proteins proved that conjugation of AuNPs with antibodies enables immobilization of antibodies with preservation of a significant antigen binding capacity. More importantly, our findings showed that the conjugation of types of anti-TNF receptors antibodies such as anti-Fn14 antibodies (PDL192 and 5B6) (Aido et al., 2021), anti-CD40, anti-4-1BB and anti-TNFR2 with gold nanoparticles confers them with potent agonism. Thus, our results suggest that AuNPs can be utilized as a platform to immobilize anti-TNFR antibodies which, on the one hand, helps to enhance their agonistic activity in comparison to "free" inactive antibodies by mimicking the effect of cell-anchored antibodies or membrane-bound TNF ligands and, on the other hand, allows to develop new generations of drug delivery systems. These constructs are characterized with their biocompatibility and their tunable synthesis process. In a further work part, we combined the benefits of the established system of Ab-AuNPs with materials used widely in the modern biofabrication approaches such as the photo-crosslinked hydrogels, methacrylate-modified gelatin (GelMA), combined with embedded variants of human cell lines. The acquired results demonstrated clearly that the attaching of proteins like antibodies to gold nanoparticles might reduce their release rate from the crosslinked hydrogels upon the very low diffusion of gold nanoparticles from the solid constructs to the surrounding medium yielding long-term local functioning proteins-attached particles. Moreover, our finding suggests that hydrogel-embedded AuNP-immobilized antibodies, e.g. anti-TNFα-AuNPs or anti-IL1-AuNPs enable local inhibitory functions, To sum up, our results demonstrate that AuNPs can act as a platform to attach anti-TNFR antibodies to enhance their agonistic activity by resembling the output of cell-anchoring or membrane bounding. Gold nanoparticles are considered, thus, as promising tool to develop the next generation of drug delivery systems, which may contribute to cancer therapy. On top of that, the embedding of anti-inflammatory-AuNPs in the biofabricated hydrogel presents new innovative strategy of the treatment of autoinflammatory diseases.}, subject = {Nanopartikel}, language = {en} } @phdthesis{Prell2024, author = {Prell, Andreas}, title = {The effects of paternal age on DNA methylation of developmentally important genes in human and bovine sperm}, doi = {10.25972/OPUS-34786}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347866}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Western societies are steadily becoming older undergoing a clear trend of delayed parenthood. Children of older fathers have an undeniably higher risk for certain neurodevelopmental disorders and other medical conditions. Changes in the epigenetic landscape and especially in DNA methylation patterns are likely to account for a portion of this inherited disease susceptibility. DNA methylation changes during the ageing process are a well-known epigenetic feature. These so-called age-DMRs exist in developmentally important genes in the methylome of several mammalian species. However, there is only a minor overlap between the age-DMR datasets of different studies. We therefore replicated age-DMRs (which were obtained from a genome wide technique) by applying a different technical approach in a larger sample number. Here, this study confirmed 10 age-DMRs in the human and 4 in the bovine sperm epigenome from a preliminary candidate list based on RRBS. For this purpose, we used bisulphite Pyrosequencing in 94 human and 36 bovine sperm samples. These Pyrosequencing results confirm RRBS as an effective and reliable method to screen for age-DMRs in the vertebrate genome. To decipher whether paternal age effects are an evolutionary conserved feature of mammalian development, we compared methylation patterns between human and bovine sperm in orthologous regulatory regions. We discovered that the level of methylation and the age effect are both species-specific and speculate that these methylation marks reflect the lineage-specific development of each species to hit evolutionary requirements and adaptation processes. Different methylation levels between species in developmentally important genes also imply a differing mutational burden, representing a potential driver for point mutations and consequently deviations in the underlying DNA sequence of different species. Using the example of different haplotypes, this study showed the great effect of single base variations on the methylation of adjacent CpGs. Nonetheless, this study could not provide further evidence or a mechanism for the transfer of epigenetic marks to future generations. Therefore, further research in tissues from the progeny of old and young fathers is required to determine if the observed methylation changes are transmitted to the next generation and if they are associated with altered transcriptional activity of the respective genes. This could provide a direct link between the methylome of sperm from elderly fathers and the development potential of the next generation.}, subject = {Epigenetik}, language = {en} } @phdthesis{Endres2024, author = {Endres, Leo Maximilian}, title = {Development of multicellular \(in\) \(vitro\) models of the meningeal blood-CSF barrier to study \(Neisseria\) \(meningitidis\) infection}, doi = {10.25972/OPUS-34621}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346216}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Neisseria meningitidis (the meningococcus) is one of the major causes of bacterial meningitis, a life-threatening inflammation of the meninges. Traversal of the meningeal blood-cerebrospinal fluid barrier (mBCSFB), which is composed of highly specialized brain endothelial cells (BECs), and subsequent interaction with leptomeningeal cells (LMCs) are critical for disease progression. Due to the human-exclusive tropism of N. meningitidis, research on this complex host-pathogen interaction is mostly limited to in vitro studies. Previous studies have primarily used peripheral or immortalized BECs alone, which do not retain relevant barrier phenotypes in culture. To study meningococcal interaction with the mBCSFB in a physiologically more accurate context, BEC-LMC co-culture models were developed in this project using BEC-like cells derived from induced pluripotent stem cells (iBECs) or hCMEC/D3 cells in combination with LMCs derived from tumor biopsies. Distinct BEC and LMC layers as well as characteristic expression of cellular markers were observed using transmission electron microscopy (TEM) and immunofluorescence staining. Clear junctional expression of brain endothelial tight and adherens junction proteins was detected in the iBEC layer. LMC co-culture increased iBEC barrier tightness and stability over a period of seven days, as determined by sodium fluorescein (NaF) permeability and transendothelial electrical resistance (TEER). Infection experiments demonstrated comparable meningococcal adhesion and invasion of the BEC layer in all models tested, consistent with previously published data. While only few bacteria crossed the iBEC-LMC barrier initially, transmigration rates increased substantially over 24 hours, despite constant high TEER. After 24 hours of infection, deterioration of the barrier properties was observed including loss of TEER and altered expression of tight and adherens junction components. Reduced mRNA levels of ZO-1, claudin-5, and VE-cadherin were detected in BECs from all models. qPCR and siRNA knockdown data suggested that transcriptional downregulation of these genes was potentially but not solely mediated by Snail1. Immunofluorescence staining showed reduced junctional coverage of occludin, indicating N. meningitidis-induced post-transcriptional modulation of this protein, as previous studies have suggested. Together, these results suggest a potential combination of transcellular and paracellular meningococcal traversal of the mBCSFB, with the more accessible paracellular route becoming available upon barrier disruption after prolonged N. meningitidis infection. Finally, N. meningitidis induced cellular expression of pro-inflammatory cytokines and chemokines such as IL-8 in all mBCSFB models. Overall, the work described in this thesis highlights the usefulness of advanced in vitro models of the mBCSFB that mimic native physiology and exhibit relevant barrier properties to study infection with meningeal pathogens such as N. meningitidis.}, subject = {Bakterielle Hirnhautentz{\"u}ndung}, language = {en} } @phdthesis{Werthmueller2024, author = {Werthm{\"u}ller, Dominic Pascal}, title = {Relevance of bioaccessibility for the oral bioavailability of poorly water-soluble drugs}, doi = {10.25972/OPUS-29920}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299200}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Poor or variable oral bioavailability is of major concern regarding safety and efficacy for the treatment of patients with poorly water-soluble drugs (PWSDs). The problem statement of this work involves a pharmaceutical development perspective, the physicochemical basis of the absorption process and physiological / biopharmaceutical aspects. A methodology was developed aiming at closing the gap between drug liberation and dissolution on the one hand and the appearance of drug in the blood on the other. Considering what is out of control from a formulation development perspective, a clear differentiation between bioavailability and bioaccessibility was necessary. Focusing on the absorption process, bioaccessibility of a model compound, a poorly soluble but well permeable weak base, was characterized by means of flux across artificial biomimetic membranes. Such setups can be considered to reasonably mimic relevant oral absorption resistances in vitro in terms of diffusion through an unstirred water layer (UWL) and a lipidic barrier. Mechanistic understanding of the driving force for permeation was gained by differentiating drug species and subsequently linking them to the observed transfer rates using a bioaccessibility concept. The three key species that need to be differentiated are molecularly dissolved drug, drug associated in solution with other components (liquid reservoir) and undissolved drug (solid reservoir). An innovative approach to differentiate molecularly dissolved drug from the liquid reservoir using ultracentrifugation in combination with dynamic light scattering as control is presented. A guidance for rational formulation development of PWSDs is elaborated based on the employed model compound. It is structured into five guiding questions to help drug formulation scientists in selecting drug form, excipients and eventually the formulation principle. Overall, the relevance but also limitations of characterizing bioaccessibility were outlined with respect to practical application e.g. in early drug formulation development.}, subject = {Bioverf{\"u}gbarkeit}, language = {en} } @unpublished{SeitzJungnickelKleiberetal.2024, author = {Seitz, Florian and Jungnickel, Tina and Kleiber, Nicole and Kretschmer, Jens and Dietzsch, Julia and Adelmann, Juliane and Bohnsack, Katherine E. and Bohnsack, Markus T. and H{\"o}bartner, Claudia}, title = {Atomic mutagenesis of N\(^6\)-methyladenosine reveals distinct recognition modes by human m\(^6\)A reader and eraser proteins}, series = {Journal of the American Chemical Society}, journal = {Journal of the American Chemical Society}, doi = {10.1021/jacs.4c00626}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352376}, year = {2024}, abstract = {N\(^6\)-methyladenosine (m\(^6\)A) is an important modified nucleoside in cellular RNA associated with multiple cellular processes and is implicated in diseases. The enzymes associated with the dynamic installation and removal of m\(^6\)A are heavily investigated targets for drug research, which requires detailed knowledge of the recognition modes of m\(^6\)A by proteins. Here, we use atomic mutagenesis of m\(^6\)A to systematically investigate the mechanisms of the two human m\(^6\)A demethylase enzymes FTO and ALKBH5 and the binding modes of YTH reader proteins YTHDF2/DC1/DC2. Atomic mutagenesis refers to atom-specific changes that are introduced by chemical synthesis, such as the replacement of nitrogen by carbon atoms. Synthetic RNA oligonucleotides containing site-specifically incorporated 1-deaza-, 3-deaza-, and 7-deaza-m\(^6\)A nucleosides were prepared by solid-phase synthesis and their RNA binding and demethylation by recombinant proteins were evaluated. We found distinct differences in substrate recognition and transformation and revealed structural preferences for the enzymatic activity. The deaza m\(^6\)A analogues introduced in this work will be useful probes for other proteins in m\(^6\)A research.}, language = {en} } @phdthesis{Held2024, author = {Held, Helena}, title = {The effectiveness of non-occlusal therapies in relation to the chronicity of temporomandibular disorders: a systematic review with meta-analysis}, doi = {10.25972/OPUS-34799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347990}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Background: That a differentiated treatment of subjects with low and high levels of disabling pain might be necessarily has only been suspected but not sufficiently confirmed so far. Furthermore, the effectiveness of extraoral therapy methods for TMD is still controversial in the literature. The present work could make an important contribution to this. Objectives: Five systematic reviews with meta-analysis were conducted to investigate the efficacy of extraoral therapies (acupuncture, laser, medication, psychosocial interventions, and physiotherapy) in the treatment of TMD in relation to the degree of chronicity of pain. Literature sources: With this objective, the databases Pubmed/MEDLINE, EMBASE, Cochrane Library, Livivo, OpenGrey, drks.de, Clinicaltrials.gov. were searched. Criteria for the selection of suitable studies: Adults suffering from painful TMD and treated with either acupuncture, laser, medication, psychosocial interventions, or physiotherapy. The studies were then examined for evidence in the subjects' characteristics suggesting that they were suffering from chronic TMD in terms of pain dysfunction. These included a high score on the GCPS, resistance to undergone treatments, multilocular pain, depression, and regular use of pain medication. The effectiveness of the five interventions was then differentiated according to the suspected degree of chronicity. Effectiveness was assessed by the following outcomes: patient- related current pain intensity, MMO, pain on palpation, temporomandibular joint sounds, depression, and somatization. Study evaluation: After the assessment of the studies, the quality assessment (Risk of Bias Tool of the Cochrane Institute) and the extraction of the data were conducted. After that five meta-analyses were carried out for each of the five interventions using the Review Manager of the Cochrane Institute (RevMan 5.3) Results: Acupuncture and dry needling were statistically significantly more effective in providing short-term pain relief compared to the control group in patients with low disability pain (p=0.04) and (p=0.02), respectively. Acupuncture or dry needling did not show a significant result in the improvement of MMO in the short-term period. Laser therapy is more effective in relieving pain (p<0.0001) and functional outcomes (p=0.03) in the short term compared to placebo for low disability pain. Botulinum toxin (p=0.003) and NSAIDs (p=0.03) showed significantly better short-term improvement in pain intensity for high disability pain. Low disability pain is significantly better treated by psychosocial interventions than by other treatments in terms of long-term pain relief (more than 12 months) (p=0.02). Patients with high disability pain had significantly lower depression scores after psychosocial interventions than after other treatments (p=0.008). Physiotherapy showed a statistically significant short-term analgesic effect in patients with high disability pain compared to placebo (p=0.04). Manual Therapy (MT) showed a statistically significant short-term analgesic effect in high disability pain compared to the control group (p=0.01). Patients with low disability pain showed a statistically significant short-term pain-relieving effect with the single intervention of MT in combination with exercise compared to the control groups (p=0.003). A statistically significant result in the improvement of MMO was found in the short-term period in low disability pain for the single interventions of physiotherapy (p=0.008) and physiotherapy in combination with another treatment compared to other treatments (p=0.03), MT compared to the control group (p=0.03) and physiotherapy compared to splint therapy (p=0.03). Clinical conclusion: Individual interventions of the five extraoral therapies confirm the hypothesis that painful TMDs respond differently to established therapies depending on the degree of chronic pain-related disability and that the prognosis of therapy is significantly influenced by the degree of chronic pain- related disability of the condition, according to the GCPS. Registration number of the review at PROSPERO: CRD42020202558 Keywords: meta-analysis, systematic review, temporomandibular disorders, extra oral therapy, acupuncture, laser, medication, psychosocial interventions, physiotherapy, low disability, high disability, pain, chronification}, subject = {Metaanalyse}, language = {en} } @phdthesis{Maier2024, author = {Maier, Matthias}, title = {Inorganic and Inorganic-Organic Hybrid Polymers Containing BN Units in the Main Chain}, doi = {10.25972/OPUS-35153}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351536}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {π-Conjugated organic polymers have attracted tremendous attention in the last decades, and the interest in these materials is mainly driven by their applicability in next-generation electronic and optoelectronic devices (OLEDs, OFETs, photovoltaics). The partial or complete replacement of carbon atoms by main group elements in conjugated polymers can significantly change the characteristics and applications of these macromolecules. In this work, a class of inorganic polymers comprising a backbone of exclusively boron and nitrogen atoms (poly(iminoborane)s, PIBs) and their monodisperse oligomers is described. In addition, novel inorganic-organic hybrid polymers containing BN units in their polymer backbone were synthesized and characterized. In chapter 2.1, the development of catalytic B-N coupling routes for the controlled synthesis of macromolecular materials is described. While the reaction of an N-silyl-B-chloro-aminoborane with the electrophilic reagent trimethylsilyl triflate led to effective B-N coupling, the reaction with a silver(I) salt resulted in an intramolecular Cl/Me exchange between the boron and silicon centers. In chapter 2.2-2.4, the study of oligo- and poly(iminoborane)s is discussed. Monodisperse and cyclolinear oligo(iminoborane)s based on diazaborolidines with up to 7 boron and 8 nitrogen atoms were synthesized by successively extending the B-N main chain. However, the use of benzodiazaborolines only led to limited BN catenation. Furthermore, the redistribution processes resulting from the reaction of longer oligomers with non-stoichiometric amounts of (di)halogenated boranes is reported. In chapter 2.5-2.6, the synthesis of 1,2,5-azadiborolanes as building blocks for the synthesis of poly(iminoborane)s and inorganic-organic hybrid polymers is described. While the attempt to apply an azadiborolane with sterically demanding groups on the boron-bridging ethylene unit for the construction of PIB was unfeasible, it was successfully incorporated in inorganic-organic hybrid polymers. Photophysical studies indicated π-conjugation along the polymer chain. A first attempt to synthesize PIBs based on azadiborolanes with unsubstituted ethylene units showed promising results. In chapter 2.7-2.8, a comprehensive study of poly(arylene iminoborane)s, which are BN analogs of poly(arylene vinylene)s is described, and the properties of four polymers as well as twelve monodisperse oligomers were investigated. Photophysical investigations of the monomers, dimers and polymers showed a systematic bathochromic shift of the absorption maximum with increasing chain length and thiophene content. Based on TD-DFT calculations of the model oligomers, the lowest-energy absorption band could be assigned to HOMO to LUMO transitions with π-π* character. The oligo- and poly(arylene iminoborane)s showed only very weak to no emission in solution but they were emissive in the solid state. For four oligomers the aggregation induced emission (AIE) in a THF/water mixture was investigated and DLS studies confirmed the formation of nanoaggregates. In chapter 2.9, oligo- and polymerizations of sulfur-containing building blocks and subsequent pH-triggered degradation of the products is described. While a sulfilimine-containing oligomer could not be isolated, the sulfone-, sulfoximine-, and sulfoxide-containing molecular oligomers and polymers could be successfully synthesized by B=N or B-O bond formation reactions. The sulfur-containing building blocks were successfully released under acidic or basic conditions, which was confirmed by NMR spectroscopy and mass spectrometry.}, subject = {Anorganische Polymere}, language = {en} } @phdthesis{Schmid2024, author = {Schmid, Kerstin}, title = {Integrative, three-dimensional \(in\) \(silico\) modeling of gas exchange in the human alveolus}, doi = {10.25972/OPUS-35182}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351823}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die Lunge erf{\"u}llt durch den Austausch von Atemgasen eine {\"u}berlebenswichtige Aufgabe. Der Gasaustausch erfolgt durch einen einfachen, aber entscheidenden passiven Diffusionsprozess. Dieser findet in den Alveolen statt, ballonartigen Strukturen, die an die peripheren Atemwege grenzen. Alveolen sind von einem dichten Netz aus kleinen Kapillaren umgeben. Hier kommt die eingeatmete Luft in unmittelbare N{\"a}he zu dem vom Herzen kommenden sauerstoffarmen Blut und erm{\"o}glicht den Austausch von Sauerstoff und Kohlenstoffdioxid {\"u}ber deren Konzentrationsgradienten. Die Effizienz des Gasaustauschs kann anhand von Indikatoren wie der Sauerstoffdiffusionskapazit{\"a}t der Lunge und der Reaktionshalbzeit gemessen werden. Beim Menschen besteht eine betr{\"a}chtliche Diskrepanz zwischen physiologischen Sch{\"a}tzungen der Diffusionskapazit{\"a}t und der theoretischen Maximalkapazit{\"a}t unter optimalen strukturellen Bedingungen (der morphologischen Sch{\"a}tzung). Diese Diskrepanz wird durch eine Reihe ineinandergreifender Faktoren beeinflusst, darunter strukturelle Elemente wie die Oberfl{\"a}che und die Dicke der Diffusionsbarriere sowie physiologische Faktoren wie die Blutflussdynamik. Um die verschiedenen Rollen dieser Faktoren zu entschl{\"u}sseln, untersuchten wir, wie die morphologischen und physiologischen Eigenschaften der menschlichen alveol{\"a}ren Mikroumgebung kollektiv und individuell den Prozess des Gasaustauschs beeinflussen. Zu diesem Zweck entwickelten wir einen integrativen in silico Ansatz, der 3D morphologische Modellierung und Simulation von Blutfluss und Sauerstofftransport kombiniert. Im Mittelpunkt unseres Ansatzes steht die Simulationssoftware Alvin, die als interaktive Plattform f{\"u}r das zugrundeliegende mathematische Modell des Sauerstofftransports in der Alveole dient. Unser r{\"a}umlich-zeitliches Modell wurde durch die Integration und Erweiterung bestehender mathematischer Modelle entwickelt und liefert Ergebnisse, die mit experimentellen Daten im Einklang stehen. Alvin erm{\"o}glicht eine immersive Auseinandersetzung mit dem simulierten Gasaustausch, indem sie Parameter{\"a}nderungen in Echtzeit und die Ausf{\"u}hrung mehrerer Simulationsinstanzen gleichzeitig erm{\"o}glicht w{\"a}hrend sie ein detailliertes quantitatives Feedback liefert. Die beteiligten morphologischen und physiologischen Parameter wurden mit einem Fokus auf der Mikrovaskulatur weiter untersucht. Durch die Zusammenstellung stereologischer Daten aus der Literatur und geometrischer 3D-Modellierung erstellten wir ein "sheet-flow" Modell als realistische Darstellung des menschlichen alveol{\"a}ren Kapillarnetzwerks. Blutfluss wurde mit Hilfe numerischer Str{\"o}mungsdynamik simuliert. Unsere Ergebnisse stimmen mit fr{\"u}heren Sch{\"a}tzungen {\"u}berein und unterstreichen die entscheidende Rolle von Viskosit{\"a}tsmodellen bei der Vorhersage des Druckabfalls in der Mikrovaskulatur. Dar{\"u}ber hinaus zeigten wir, wie unser Ansatz genutzt werden kann, um strukturelle Details wie die Konnektivit{\"a}t des alveol{\"a}ren Kapillarnetzes mit dem Gef{\"a}ßbaum anhand von Blutflussindizes zu untersuchen. Es ist wichtig zu betonen, dass wir uns bislang auf verschiedene Datenquellen st{\"u}tzten und dass f{\"u}r weitere Fortschritte eine experimentelle Vailidierung erforderlich ist. Die Integration unserer Ergebnisse in Alvin erm{\"o}glichte die Quantifizierung des simulierten Gasaustauschprozesses {\"u}ber die Sauerstoffdiffusionskapazit{\"a}t und die Reaktionshalbzeit. Neben der Bewertung der kollektiven Einfl{\"u}sse der morphologischen und physiologischen Eigenschaften erleichterte unsere interaktive Software auch die Bewertung einzelner Parameter{\"a}nderungen. Die Betrachtung des Blutvolumens und der f{\"u}r den Gasaustausch zur Verf{\"u}gung stehenden Oberfl{\"a}che ergab lineare Korrelationen mit der Diffusionskapazit{\"a}t. Die Blutflussgeschwindigkeit hatte einen positiven, nichtlinearen Effekt auf die Diffusionskapazit{\"a}t. Die Reaktionshalbzeit best{\"a}tigte, dass der Gasaustauschprozess in der Regel nicht diffusionslimitiert ist. Insgesamt lieferte unser Alveolenmodell einen Wert f{\"u}r die Diffusionskapazit{\"a}t, der in der Mitte der fr{\"u}heren physiologischen und morphologischen Sch{\"a}tzung lag. Daraus l{\"a}sst sich schließen, dass Ph{\"a}nomene auf Alveolarebene zu 50\% der Limitierung der Diffusionskapazit{\"a}t beitragen, die in vivo eintreten. Zusammenfassend l{\"a}sst sich sagen, dass unser integrativer in silico Ansatz verschiedene strukturelle und funktionelle Einfl{\"u}sse auf den alveol{\"a}ren Gasaustausch aufschl{\"u}sselt und damit die traditionelle Forschung in der Atemwegsforschung erg{\"a}nzt. Zus{\"a}tzlich zeigen wir seinen Nutzen in der Lehre oder bei der Interpretation ver{\"o}ffentlichter Daten auf. Um unser Verst{\"a}ndnis zu verbessern, sollten k{\"u}nftige Arbeiten vorrangig darauf ausgerichtet sein, einen zusammenh{\"a}ngenden experimentellen Datensatz zu erhalten und ein geeignetes Viskosit{\"a}tsmodell f{\"u}r Blutflusssimulationen zu finden.}, subject = {Gasaustausch}, language = {en} } @phdthesis{Scherz2024, author = {Scherz, Jan}, title = {Weak Solutions to Mathematical Models of the Interaction between Fluids, Solids and Electromagnetic Fields}, doi = {10.25972/OPUS-34920}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349205}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {We analyze the mathematical models of two classes of physical phenomena. The first class of phenomena we consider is the interaction between one or more insulating rigid bodies and an electrically conducting fluid, inside of which the bodies are contained, as well as the electromagnetic fields trespassing both of the materials. We take into account both the cases of incompressible and compressible fluids. In both cases our main result yields the existence of weak solutions to the associated system of partial differential equations, respectively. The proofs of these results are built upon hybrid discrete-continuous approximation schemes: Parts of the systems are discretized with respect to time in order to deal with the solution-dependent test functions in the induction equation. The remaining parts are treated as continuous equations on the small intervals between consecutive discrete time points, allowing us to employ techniques which do not transfer to the discretized setting. Moreover, the solution-dependent test functions in the momentum equation are handled via the use of classical penalization methods. The second class of phenomena we consider is the evolution of a magnetoelastic material. Here too, our main result proves the existence of weak solutions to the corresponding system of partial differential equations. Its proof is based on De Giorgi's minimizing movements method, in which the system is discretized in time and, at each discrete time point, a minimization problem is solved, the associated Euler-Lagrange equations of which constitute a suitable approximation of the original equation of motion and magnetic force balance. The construction of such a minimization problem is made possible by the realization that, already on the continuous level, both of these equations can be written in terms of the same energy and dissipation potentials. The functional for the discrete minimization problem can then be constructed on the basis of these potentials.}, subject = {Fluid-Struktur-Wechselwirkung}, language = {en} } @phdthesis{Allgaier2024, author = {Allgaier, Johannes}, title = {Machine Learning Explainability on Multi-Modal Data using Ecological Momentary Assessments in the Medical Domain}, doi = {10.25972/OPUS-35118}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351189}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Introduction. Mobile health (mHealth) integrates mobile devices into healthcare, enabling remote monitoring, data collection, and personalized interventions. Machine Learning (ML), a subfield of Artificial Intelligence (AI), can use mHealth data to confirm or extend domain knowledge by finding associations within the data, i.e., with the goal of improving healthcare decisions. In this work, two data collection techniques were used for mHealth data fed into ML systems: Mobile Crowdsensing (MCS), which is a collaborative data gathering approach, and Ecological Momentary Assessments (EMA), which capture real-time individual experiences within the individual's common environments using questionnaires and sensors. We collected EMA and MCS data on tinnitus and COVID-19. About 15 \% of the world's population suffers from tinnitus. Materials \& Methods. This thesis investigates the challenges of ML systems when using MCS and EMA data. It asks: How can ML confirm or broad domain knowledge? Domain knowledge refers to expertise and understanding in a specific field, gained through experience and education. Are ML systems always superior to simple heuristics and if yes, how can one reach explainable AI (XAI) in the presence of mHealth data? An XAI method enables a human to understand why a model makes certain predictions. Finally, which guidelines can be beneficial for the use of ML within the mHealth domain? In tinnitus research, ML discerns gender, temperature, and season-related variations among patients. In the realm of COVID-19, we collaboratively designed a COVID-19 check app for public education, incorporating EMA data to offer informative feedback on COVID-19-related matters. This thesis uses seven EMA datasets with more than 250,000 assessments. Our analyses revealed a set of challenges: App user over-representation, time gaps, identity ambiguity, and operating system specific rounding errors, among others. Our systematic review of 450 medical studies assessed prior utilization of XAI methods. Results. ML models predict gender and tinnitus perception, validating gender-linked tinnitus disparities. Using season and temperature to predict tinnitus shows the association of these variables with tinnitus. Multiple assessments of one app user can constitute a group. Neglecting these groups in data sets leads to model overfitting. In select instances, heuristics outperform ML models, highlighting the need for domain expert consultation to unveil hidden groups or find simple heuristics. Conclusion. This thesis suggests guidelines for mHealth related data analyses and improves estimates for ML performance. Close communication with medical domain experts to identify latent user subsets and incremental benefits of ML is essential.}, subject = {Maschinelles Lernen}, language = {en} } @phdthesis{Daubinger2024, author = {Daubinger, Philip}, title = {Electrochemical and Mechanical Interplay of State-of-the-Art and Next-Generation Lithium-Ion Batteries}, doi = {10.25972/OPUS-35125}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351253}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The demand for LIB with enhanced energy densities leads to increased utilization of the space within the confinements of the battery housing or to the use of electrode material with increased intrinsic specific energy densities. Both requirements result in more stress on the battery electrodes and separator during cycling or aging. However, the effect of mechanical strain on the cell's electrochemistry and thus the performance of batteries is rather unexplored compared to the impact of current or temperature, for example. The objective of this thesis was to give a better understanding of the electrochemical and mechanical interplay in current- and next-generation lithium based battery cells. Therefore, the thesis was structured into the investigations on SoA and next-generation LIBs. For SoA LIBs, the investigations of the interplay started at laboratory scale. Here, the expansion of various electrodes and also the impact of mechanical pressure and its distribution on the performance of the cells were studied. The investigations at laboratory scale was followed by an examination of the electrochemical and mechanical interactions on large format commercial LIBs which are used in BEVs. Accordingly, the effect of bracing and its effect on the performance was studied in an aging and post-mortem study. To gain a deeper understanding of the mechanical changes in LIBs, an ultrasonic study was performed for pouch cells. Here, the mechanical changes were further investigated in dependence of SoC and SoH. The effects of the mechanical stress on the performance for next-generation batteries were studied at laboratory scale. In the beginning, the expansion of next-generation anode materials such as silicon and lithium was compared with today's anode materials. Furthermore, the effect of mechanical pressure and electrolyte on the irreversible dilation and performance was investigated for lithium metal cells. Overall, it was shown that pressure has a significant effect on the performance of today's and also future LIBs. The interplay of the electrochemical and mechanical effects inside a LIB has a considerable impact on the lifetime, capacity fading and impedance increase of the batteries.}, subject = {Lithium-Ionen-Akkumulator}, language = {en} } @phdthesis{Seitzer2024, author = {Seitzer, Moritz}, title = {Quality and composition of anthelmintic medicines available in Eastern and Western Africa: an \({in-vitro}\) analysis of Albendazole, Mebendazole and Praziquantel}, doi = {10.25972/OPUS-35094}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350947}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Even though the international combat against Neglected Tropical Diseases such as schistosomiasis or soil-transmitted helminthiases depends on reliable therapeutics, anthelminthic pharmacovigilance has been neglected on many national African drug markets. Therefore, quality and composition of 88 different batches of Albendazole, Mebendazole and Praziquantel locally collected from randomly selected facilities in Western Burkina Faso, Southeast C{\^o}te d'Ivoire, Southwest Ghana and Northwest Tanzania were analysed. Visual examination of both packaging and samples was performed according to the WHO 'Be Aware' tool. Products were then screened with the GPHF Minilab, consisting of tests of mass uniformity, disintegration times and thin-layer chromatography (TLC). Confirmatory tests were performed according to international pharmacopoeiae, applying assays for dissolution profiles and high-performance liquid chromatography (HPLC). Despite minor irregularities, appearance of the products did not hint at falsified medicines. However, 19.6 \% of the brands collected in Ghana and Tanzania were not officially licensed for sale. Mass uniformity was confirmed in 53 out of 58 brands of tablets. 41 out of 56 products passed disintegration times; 10 out of the 15 failing products did not disintegrate at all. TLC results did not reveal any falsifications or pronounced dosing errors. HPLC findings confirmed the TLC results despite shifted specification limits: ten of the 83 tested batches contained less than 90 \%, none more than 110 \% label claim. However, no more than 46.3 \% (31 / 67) of the tablet batches assayed passed the respective criteria for dissolution. In the four study countries, no falsified anthelminthic medicine was encountered. The active pharmaceutical ingredient was not found to either exceed or distinctively fall below specification limits. Galenic characteristics as most critical criteria however, especially dissolution profiles, revealed substantial deficits.}, subject = {Wurmmittel}, language = {en} } @phdthesis{Behne2024, author = {Behne, Robert Stefan Friedrich}, title = {Development Of A Human iPSC-Derived Cortical Neuron Model Of Adaptor- Protein-Complex-4-Deficiency}, doi = {10.25972/OPUS-35139}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351390}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Adaptor-protein-4-deficiency (AP-4-deficiency) is an autosomal-recessive childhood- onset form of complicated hereditary spastic paraplegia (HSP) caused by bi-allelic loss- of-function mutations in one of the four subunits of the AP-4-complex. These four conditions are named SPG47 (AP4B1, OMIM \#614066), SPG50 (AP4M1, OMIM \#612936), SPG51 (AP4E1, OMIM \#613744) and SPG52 (AP4S1, OMIM \#614067), respectively and all present with global developmental delay, progressive spasticity and seizures. Imaging features include a thinning of the corpus callosum, ventriculomegaly and white matter changes. AP-4 is a highly conserved heterotetrameric complex, which is responsible for polarized sorting of transmembrane cargo including the autophagy- related protein 9 A (ATG9A). Loss of any of the four subunits leads to an instable complex and defective sorting of AP-4-cargo. ATG9A is implicated in autophagosome formation and neurite outgrowth. It is missorted in AP-4-deficient cells and CNS-specific knockout of Atg9a in mice results in a phenotype reminiscent of AP-4-deficiency. However, the AP-4-related cellular phenotypes including ATG9A missorting have not been investigated in human neurons. Thus, the aim of this study is to provide the first human induced pluripotent stem cell- derived (iPSC) cortical neuron model of AP-4-deficiency to explore AP-4-related phenotypes in preparation for a high-content screening. Under the hypothesis that AP-4- deficiency leads to ATG9A missorting, elevated ATG9A levels, impaired autophagy and neurite outgrowth in human iPSC-derived cortical neurons, in vitro biochemical and imaging assays including automated high-content imaging and analysis were applied. First, these phenotypes were investigated in fibroblasts from three patients with compound heterozygous mutations in the AP4B1 gene and their sex-matched parental controls. The same cell lines were used to generate iPSCs and differentiate them into human excitatory cortical neurons. This work shows that ATG9A is accumulating in the trans-Golgi-network in AP-4- deficient human fibroblasts and that ATG9A levels are increased compared to parental controls and wild type cells suggesting a compensatory mechanism. Protein levels of the AP4E1-subunit were used as a surrogate marker for the AP-4-complex and were decreased in AP-4-deficient fibroblasts with co-immunoprecipitation confirming the instability of the complex. Lentiviral re-expression of the AP4B1-subunit rescues this corroborating the fact that a stable AP-4-complex is needed for ATG9A trafficking. Surprisingly, autophagic flux was present in AP-4-deficient fibroblasts under nutrient- rich and starvation conditions. These phenotypic markers were evaluated in iPSC-derived cortical neurons and here, a robust accumulation of ATG9A in the juxtanuclear area was seen together with elevated ATG9A protein levels. Strikingly, assessment of autophagy markers under nutrient-rich conditions showed alterations in AP-4-deficient iPSC- derived cortical neurons indicating dysfunctional autophagosome formation. These findings point towards a neuron-specific impairment of autophagy and need further investigation. Adding to the range of AP-4-related phenotypes, neurite outgrowth and branching are impaired in AP-4-deficient iPSC-derived cortical neurons as early as 24h after plating and together with recent studies point towards a distinct role of ATG9A in neurodevelopment independent of autophagy. Together, this work provides the first patient-derived neuron model of AP-4-deficiency and shows that ATG9A is sorted in an AP-4-dependent manner. It establishes ATG9A- related phenotypes and impaired neurite outgrowth as robust markers for a high-content screening. This disease model holds the promise of providing a platform to further study AP-4-deficiency and to search for novel therapeutic targets.}, subject = {Adaptorproteine}, language = {en} } @phdthesis{Bieniussa2024, author = {Bieniussa, Linda Ilse}, title = {Different effects of conditional Knock-Out of Stat3 on the sensory epithelium of the Organ of Corti}, doi = {10.25972/OPUS-35143}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351434}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die Cochlea von S{\"a}ugetieren nimmt Schall als Reaktion auf Vibrationen an frequenzabh{\"a}ngigen Positionen entlang des Cochlea-Kanals wahr. Die sensorischen {\"a}ußeren Haarzellen, die von St{\"u}tzzellen umgeben sind, wirken als Signalverst{\"a}rker, indem sie ihre Zelll{\"a}nge ver{\"a}ndern k{\"o}nnen. Dies wird als Elektromotilit{\"a}t bezeichnet. Um eine korrekte elektrische {\"U}bertragung bei mechanischen Kr{\"a}ften zu gew{\"a}hrleisten, ist ein gewisser Widerstand des sensorischen Epithels eine Voraussetzung f{\"u}r die fehlerfreie Weiterleitung von H{\"o}rinformationen. Dieser Widerstand wird durch Mikrotubuli und deren posttranslationalen Modifikationen in den St{\"u}tzzellen des sensorischen Epithels der Cochlea gew{\"a}hrleistet. Stat3 ist ein Transkriptionsfaktor, der an verschiedenen Phosphorylierungsstellen, sowie je nach Zelltyp und aktiviertem Signalweg an vielen zellul{\"a}ren Prozessen wie Differenzierung, Entz{\"u}ndung, Zell{\"u}berleben und Mikrotubuli-Dynamik beteiligt ist. W{\"a}hrend Stat3 ein breites Spektrum an intrazellul{\"a}ren Funktionen hat, stellte sich die Frage, wie und ob Stat3 in den Zellen des Cortischen Organ einen Einfluss auf den H{\"o}rprozess hat. Um dies zu testen, wurde das Cre/loxp-System verwendet, um Stat3 in den {\"a}ußeren Haarzellen oder den St{\"u}tzzellen entweder vor oder nach H{\"o}rbeginn von M{\"a}usen konditional auszuschalten. Um das H{\"o}rverm{\"o}gen zu erfassen, wurden DPOAE- und ABR-Messungen durchgef{\"u}hrt, w{\"a}hrend molekulare und morphologische Untersuchungen mittels Sequenzierung und Immunhistochemie durchgef{\"u}hrt wurden. Eine konditioneller Knock-Out von Stat3 vor und nach dem Beginn des H{\"o}rens in {\"a}ußeren Haarzellen f{\"u}hrt zu leichten H{\"o}rsch{\"a}den, w{\"a}hrend Synapsen, Nervenfasern und Mitochondrien nicht betroffen waren. Die Analyse der Sequenzierung von {\"a}ußeren Haarzellen aus M{\"a}usen mit konditionellem Knock-Out vor dem Beginn des H{\"o}rens ergab eine St{\"o}rung der zellul{\"a}ren Hom{\"o}ostase und der extrazellul{\"a}ren Signale. Ein konditioneller Knock-Out von Stat3 in den {\"a}ußeren Haarzellen nach Beginn des H{\"o}rens f{\"u}hrte zu einem fr{\"u}h-entz{\"u}ndlichen Signalweg mit erh{\"o}hter Zytokinproduktion und der Hochregulierung des NF-κB-Wegs. In den St{\"u}tzzellen f{\"u}hrte ein kondioneller Knock-Out von Stat3 nur nach dem Beginn des H{\"o}rens zu einer H{\"o}rbeeintr{\"a}chtigung. Synapsen, Nervensoma und -fasern waren jedoch von einem konditionellen Knock-Out von Stat3 in St{\"u}tzzellen nicht betroffen. Dennoch war die detyronisierte Modifikation der Mikrotubuli ver{\"a}ndert, was zu einer Instabilit{\"a}t der St{\"u}tzzellen, insbesondere der Phalangealforts{\"a}tze, f{\"u}hrte, was wiederum zu einer Instabilit{\"a}t des Epithels w{\"a}hrend des H{\"o}rvorgangs f{\"u}hrte. Zusammenfassend l{\"a}sst sich sagen, dass ein konditioneller Knock-Out von Stat3 in Zellen des Cortischen Organs zu einer H{\"o}rst{\"o}rung f{\"u}hrte. W{\"a}hrend ein konditioneller Knock-Out in {\"a}ußeren Haarzellen eine erh{\"o}hte Zytokinproduktion zur Folge hatte, verloren die St{\"u}tzzellen ihre Zellstabilit{\"a}t aufgrund einer verminderten detyronisierten Modifikation der Mikrotubuli. Insgesamt deuten die Ergebnisse darauf hin, dass Stat3 ein wichtiges Protein f{\"u}r die H{\"o}rleistung ist. Es sind jedoch weitere Untersuchungen des molekularen Mechanismus erforderlich, um die Rolle von Stat3 in den Zellen des Corti-Organs zu verstehen.}, subject = {Audiologie}, language = {en} } @phdthesis{Pekarek2024, author = {Pek{\´a}rek, Luk{\´a}š}, title = {Single-Molecule Approaches To Study Frameshifting Mechanisms}, doi = {10.25972/OPUS-34611}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346112}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The RNAs of many viruses contain a frameshift stimulatory element (FSE) that grants access to an alternate reading frame via -1 programmed ribosomal frameshifting (PRF). This -1PRF is essential for effective viral replication. The -1PRF efficiency relies on the presence of conserved RNA elements within the FSE, such as a slippery sequence, spacer, and a downstream secondary structure - often a hairpin or a pseudoknot. The PRF efficiency is also affected by trans-acting factors such as proteins, miRNAs and metabolites. The interactions of these factors with the RNA and the translation machinery have not yet been completely understood. Traditional ensemble methods used previously to study these events focus on the whole population of molecular species. This results in innate averaging of the molecular behavior and a loss of heterogeneity information. Here, we first established the experimental workflow to study the RNA structures and the effect of potential trans-acting factors using single-molecule force spectroscopy technique, optical tweezers. Additionally, to streamline the data analysis, we developed an algorithm for automatized data processing. Next, we harnessed this knowledge to study viral RNA elements responsible for stimulation of PRF and how the presence of trans-acting factors affects the RNA behavior. We further complemented these single-molecule structural data with ensemble functional assays to gain a complex view on the dynamics behind the programmed ribosomal frameshifting. Specifically, two different viral RNA elements have been studied in the presented work. First, the dynamics of SARS-CoV-2 FSE and the role of extended sequences have been explored. Then, the mode of action of the host-encoded trans-acting factor ZAP-S inhibition of SARS-CoV-2 PRF has been examined. Finally, the mechanism of the trans-acting viral factor induced PRF in Encephalomyocarditis virus (EMCV) has been uncovered.}, language = {en} } @phdthesis{Cronje2024, author = {Cronj{\´e}, Johrine}, title = {Trust towards Virtual Humans in Immersive Virtual Reality and Influencing Factors}, doi = {10.25972/OPUS-34814}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348143}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Virtual humans (VHs) hold immense potential for collaboration in social virtual reality (VR). As VR technology advances, it's vital to assess the psychological effects on VH trust and user privacy to build meaningful social interactions in VR. In social VR, users must be able to trust the VHs they interact with as they navigate through socio-cultural activities. The evaluation of trustworthiness in VHs profoundly impacts interaction quality and user willingness to engage. Conversely, untrustworthy VHs can harm user experiences, privacy, and VR engagement. To address this, we conducted immersive VR studies, exploring how psychological factors influence user's VH trust evaluation under various psychological conditions. This research is pivotal for developing strategies to enhance user privacy, establish secure VR environments, and create a foundation of trust that supports immersive socio-cultural experiences in VR. To date, there are no established interpersonal trust measurement tools specifically for VHs in VR. In study 1 (the familiarity study) of the current thesis the VR-adjusted version of the social conditioned place preference paradigm (SCPP) by Kiser et al., (2022) was identified as a potential trust measurement tool. We tested whether the familiarity of a VH influenced trust as measured with the SCPP paradigm and other self-defined outcome measures, in a Computer Augmented Virtual Environment (CAVE). The CAVE is a VR system that combines immersive VR with real-world elements. It consists of a room-sized space where the walls are used as projection screens to display virtual scenes and objects. In this within - subject design (n = 20), half of the participants were familiarized with one VH and tasked to explore and interact in a realistic looking virtual art museum environment. The participant's evaluation of the VH's trustworthiness was measured as well as their subsequent trust behaviours. Results revealed no significant differences in the evaluation of the VH's trustworthiness nor any behavioural differences between conditions. The findings of the impact of a VH's familiarity on trust is inconclusive due to the major limitations of the paradigm. We concluded that the SCPP paradigm needs further validation and the proposed proxies of trust need to be re-evaluated. The findings were considered in the following study. The virtual maze paradigm design of Hale, (2018) was identified as a potential trust measurement tool, however several limitations are associated with its use to measure trust in VR. In study 2 (a validation study), improvements were made to the virtual maze paradigm of Hale, (2018) and a variant of this paradigm was implemented. We conducted a validation study with 70 participants in a between-subject design with VH trustworthiness as the between-subject factor. Participants wore a head-mounted display (HMD), to deliver an immersive VR experience. In our version of the virtual maze, it was the task of the users (the trustors) to navigate through a maze in VR, where they could interact with a VH (the trustee). They could choose to ask for advice and follow the advice from the VH if they wanted to. The number of times participants asked and followed advice and the time it took to respond to the given advice served as behavioural proxies/measures of trust. The two conditions (trustworthy vs. untrustworthy) did not differ in the content of the advice but in the appearance, tone of voice and engagement of the trustees (allegedly an avatar controlled by other participants). Results indicated that the experimental manipulation was successful, as participants rated the VH as more trustworthy in the trustworthy condition compared with the VH in the untrustworthy condition. Importantly, this manipulation affected the trust behaviour of participants, who, in the trustworthy condition, asked for advice and followed advice more often, indicating that the paradigm is sensitive to differences in VH's trustworthiness. Thus, our paradigm can be used to measure differences in interpersonal trust towards VHs and may serve as a valuable research tool for researchers who study trust in VR. Therefore, study 2 fills the gap in the literature, for an interpersonal trust measurement tool specifically for VHs in VR. Two experimental studies, with a sample size of 50 participants each, utilized the virtual maze paradigm where participants entered 12 rooms under different conditions. We examined the influence of cognitive load (CL) on trust towards VH in VR in study 3 (Cognitive load study), and the influence of emotional affect (Emotional affect study) on trust towards VH in VR in study 4 (EA study). In both studies, we assessed participant's evaluation of a VH's trustworthiness, along with three behavioural indicators of trust in the maze task: 1) frequency of advice asked, 2) frequency of advice followed, and 3) the time taken by participants to execute the received advice. In study 3, the CL was manipulated with the auditory 1-back task in the high cognitive load condition (HCL). In study 4, the Autobiographical Emotional Memory Task (AEMT) was used to manipulate the EA of participants in the negative emotional affect (NEA) condition. As an additional manipulation, while participants were immersed in VR, they were exposed to 12 negative pictures and sounds that was presented simultaneously to strengthen the initial manipulation. The manipulation of the within-subject factors (CL and EA) was successful in both studies, as significant differences between conditions were observed in both studies (higher CL in the HCL condition and a more negative EA in the NEA condition). However, only CL influenced participant's evaluation of the VH's trustworthiness. The VH were evaluated as significantly more trustworthy after the HCL condition. Despite the difference in trust evaluation, there was no difference in advice asking or following. Participants in study 4 asked and followed advice due to their trust in the VH and asked and followed advice equally often in both conditions. Importantly, significant differences were observed in the participants response times in both studies. In study 3 during the HCL condition participants followed advice quicker. The order in which the conditions were presented influenced the experience of CL. Participants experienced higher levels of CL and responded to advice significantly faster when low cognitive load (LCL) was presented as the first condition compared with LCL as the second condition. In study 4 participants in the NEA condition followed advice slower similar to the findings of study 3. The order in which the conditions were presented had a significant effect on the EA. Participants asked and followed advice less when the NEA condition was presented first compared with when it is presented second. Possible explanations for the findings are discussed in the thesis. Overall, this thesis offers a novel tool for trust measurement (the virtual maze paradigm) and contributes to understanding the role of psychological factors in trust towards virtual humans in virtual reality.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Lu2024, author = {Lu, Jinping}, title = {The vacuolar TPC1 channel and its luminal calcium sensing site in the luminal pore entrance}, doi = {10.25972/OPUS-25135}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251353}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The slowly activating vacuolar SV/TPC1 channel is ubiquitously expressed in plants and provides a large cation conductance in the vacuolar membrane. Thereby, monovalent (K+, Na+) and in principle also divalent cations, such as Ca2+, can pass through the channel. The SV/TPC1 channel is activated upon membrane depolarization and cytosolic Ca2+ but inhibited by luminal calcium. With respect to the latter, two luminal Ca2+ binding sites (site 1 Asp240/Asp454/Glu528, site 2 Glu239/Asp240/Glu457) were identified to coordinate luminal Ca2+. In this work, the characteristics of the SV/TPC1 channels in terms of regulation and function were further elucidated, focusing on the TPC1s of Arabidopsis thaliana and Vicia faba. For electrophysiological analysis of the role of distinct pore residues for channel gating and luminal Ca2+ sensing, TPC1 channel variants were generated by site-directed mutagenesis and transiently expressed as eGFP/eYFP-fusion constructs in Arabidopsis thaliana mesophyll protoplasts of the TPC1 loss-of-function mutant attpc1-2. 1. As visualized by confocal fluorescence laser-scanning microscopy, all AtTPC1 (WT, E605A/Q, D606N, D607N, E605A/D606N, E605Q/D606N/D607N, E457N/E605A/D606N) and VfTPC1 channel variants (WT, N458E/A607E/ N608D) were correctly targeted to the vacuole membrane. 2. Patch-clamp studies revealed that removal of one of the negative charges at position Glu605 or Asp606 was already sufficient to promote voltage-dependent channel activation with higher voltage sensitivity. The combined neutralization of these residues (E605A/D606N), however, was required to additionally reduce the luminal Ca2+ sensitivity of the AtTPC1 channel, leading to hyperactive AtTPC1 channels. Thus, the residues Glu605/Asp606 are functionally coupled with the voltage sensor of AtTPC1 channel, thereby modulating channel gating, and form a novel luminal Ca2+ sensing site 3 in AtTPC1 at the luminal entrance of the ion transport pathway. 3. Interestingly, this novel luminal Ca2+ sensing site 3 (Glu605/Asp606) and Glu457 from the luminal Ca2+ sensing site 2 of the luminal Ca2+-sensitive AtTPC1 channel were neutralized by either asparagine or alanine in the TPC1 channel from Vicia faba and many other Fabaceae. Moreover, the VfTPC1 was validated to be a hyperactive TPC1 channel with higher tolerance to luminal Ca2+ loads which was in contrast to the AtTPC1 channel features. As a result, VfTPC1 but not AtTPC1 conferred the hyperexcitability of vacuoles. When AtTPC1 was mutated for the three VfTPC1-homologous polymorphic site residues, the AtTPC1 triple mutant (E457N/E605A/D606N) gained VfTPC1-like characteristics. However, when VfTPC1 was mutated for the three AtTPC1-homologous polymorphic site residues, the VfTPC1 triple mutant (N458E/A607E/N608D) still sustained VfTPC1-WT-like features. These findings indicate that the hyperactivity of VfTPC1 is achieved in part by the loss of negatively charged amino acids at positions that - as part of the luminal Ca2+ sensing sites 2 and 3 - are homologous to AtTPC1-Glu457/Glu605/Asp606 and are likely stabilized by other unknown residues or domains. 4.The luminal polymorphic pore residues (Glu605/Asp606 in AtTPC1) apparently do not contribute to the unitary conductance of TPC1. Under symmetrical K+ conditions, a single channel conductance of about 80 pS was determined for AtTPC1 wild type and the AtTPC1 double mutant E605A/D606A. This is in line with the three-fold higher unitary conductance of VfTPC1 (232 pS), which harbors neutral luminal pore residues at the homologous sites to AtTPC1. In conclusion, by studying TPC1 channel from Arabidopsis thaliana and Vicia faba, the present thesis provides evidence that the natural TPC1 channel variants exhibit differences in voltage gating, luminal Ca2+ sensitivity and luminal Ca2+ binding sites.}, language = {en} } @phdthesis{ZimmermannneePapp2024, author = {Zimmermann [n{\´e}e Papp], Lena}, title = {Platelets as modulators of blood-brain barrier disruption and inflammation in the pathophysiology of ischemic stroke}, doi = {10.25972/OPUS-30285}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302850}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Ischemia-reperfusion injury (I/R injury) is a common complication in ischemic stroke (IS) treatment, which is characterized by a paradoxical perpetuation of tissue damage despite the successful re-establishment of vascular perfusion. This phenomenon is known to be facilitated by the detrimental interplay of platelets and inflammatory cells at the vascular interface. However, the spatio-temporal and molecular mechanisms underlying these cellular interactions and their contribution to infarct progression are still incompletely understood. Therefore, this study intended to clarify the temporal mechanisms of infarct growth after cerebral vessel recanalization. The data presented here could show that infarct progression is driven by early blood-brain-barrier perturbation and is independent of secondary thrombus formation. Since previous studies unravelled the secretion of platelet granules as a molecular mechanism of how platelets contribute to I/R injury, special emphasis was placed on the role of platelet granule secretion in the process of barrier dysfunction. By combining an in vitro approach with a murine IS model, it could be shown that platelet α-granules exerted endothelial-damaging properties, whereas their absence (NBEAL2-deficiency) translated into improved microvascular integrity. Hence, targeting platelet α-granules might serve as a novel treatment option to reduce vascular integrity loss and diminish infarct growth despite recanalization. Recent evidence revealed that pathomechanisms underlying I/R injury are already instrumental during large vessel occlusion. This indicates that penumbral tissue loss under occlusion and I/R injury during reperfusion share an intertwined relationship. In accordance with this notion, human observational data disclosed the presence of a neutrophil dominated immune response and local platelet activation and secretion, by the detection of the main components of platelet α-granules, within the secluded vasculature of IS patients. These initial observations of immune cells and platelets could be further expanded within this thesis by flow cytometric analysis of local ischemic blood samples. Phenotyping of immune cells disclosed a yet unknown shift in the lymphocyte population towards CD4+ T cells and additionally corroborated the concept of an immediate intravascular immune response that is dominated by granulocytes. Furthermore, this thesis provides first-time evidence for the increased appearance of platelet-leukocyte-aggregates within the secluded human vasculature. Thus, interfering with immune cells and/or platelets already under occlusion might serve as a potential strategy to diminish infarct expansion and ameliorate clinical outcome after IS.}, subject = {Schlaganfall}, language = {en} } @phdthesis{Abbas2024, author = {Abbas, Eid Nagy Eid}, title = {Demotic Texts from Medinet Habu (Philological, Paleographical, and Cultural Study)}, doi = {10.25972/OPUS-35265}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352653}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The current study presents a new a group of Demotic ostraca in the belongings of the Cairo Museum. A large part of this group stem from Medinet Habu in the western bank of modern Luxor in Upper Egypt and was discovered in the beginning of the thirties of the last century by the Chicago Oriental Institute (recently renamed as Institute for the Study of Ancient Cultures 'ISAC'). A small portion of the collection under consideration come from other Upper Egyptian provenances including Gebelein, Edfu, Kom Ombo, and possibly elsewhere in Thebes. The main goal of the present dissertation is to decipher, translate, and provide a philological, paleographical, and cultural analysis of the group of texts in question. The results of this study are spread over two main parts, the first of which is dedicated to the main and largest part of the collection, i.e. ostraca from Medinet Habu, while the second is concerned with ostraca from other places. The first part comprises of five sections beginning with receipts of money and in-kind payments including some receipts for the payments of the different capitation charges in the Ptolemaic and Roman Periods, a few for land-related payments, as well as others related to different Ptolemaic monopolies or trades such as a receipt for the price of oil, one for the linen tax, in addition to a unique receipt for the rarely attested fish tax. The second section includes accounts and lists of different kinds be it monetary, in-kind, agriculture, or any other type of lists or accounts that record different everyday transactions. The following section presents a relatively different type of lists, namely lists of personal names. The fourth section incorporates a variety of texts of different concerns, e.g. texts of religious nature, letters, temples oaths, or other private documents. Unidentified texts occupy the fifth and final section of the first part. The second part of the study, which comprises texts that originate from different Upper Egyptian localities, includes three sections, i.e. receipts, accounts, and lists of names.}, language = {en} } @phdthesis{Andelovic2024, author = {Andelovic, Kristina}, title = {Characterization of arterial hemodynamics using mouse models of atherosclerosis and tissue-engineered artery models}, doi = {10.25972/OPUS-30360}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303601}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Within this thesis, three main approaches for the assessment and investigation of altered hemodynamics like wall shear stress, oscillatory shear index and the arterial pulse wave velocity in atherosclerosis development and progression were conducted: 1. The establishment of a fast method for the simultaneous assessment of 3D WSS and PWV in the complete murine aortic arch via high-resolution 4D-flow MRI 2. The utilization of serial in vivo measurements in atherosclerotic mouse models using high-resolution 4D-flow MRI, which were divided into studies describing altered hemodynamics in late and early atherosclerosis 3. The development of tissue-engineered artery models for the controllable application and variation of hemodynamic and biologic parameters, divided in native artery models and biofabricated artery models, aiming for the investigation of the relationship between atherogenesis and hemodynamics Chapter 2 describes the establishment of a method for the simultaneous measurement of 3D WSS and PWV in the murine aortic arch at, using ultra high-field MRI at 17.6T [16], based on the previously published method for fast, self-navigated wall shear stress measurements in the murine aortic arch using radial 4D-phase contrast MRI at 17.6 T [4]. This work is based on the collective work of Dr. Patrick Winter, who developed the method and the author of this thesis, Kristina Andelovic, who performed the experiments and statistical analyses. As the method described in this chapter is basis for the following in vivo studies and undividable into the sub-parts of the contributors without losing important information, this chapter was not split into the single parts to provide fundamental information about the measurement and analysis methods and therefore better understandability for the following studies. The main challenge in this chapter was to overcome the issue of the need for a high spatial resolution to determine the velocity gradients at the vascular wall for the WSS quantification and a high temporal resolution for the assessment of the PWV without prolonging the acquisition time due to the need for two separate measurements. Moreover, for a full coverage of the hemodynamics in the murine aortic arch, a 3D measurement is needed, which was achieved by utilization of retrospective navigation and radial trajectories, enabling a highly flexible reconstruction framework to either reconstruct images at lower spatial resolution and higher frame rates for the acquisition of the PWV or higher spatial resolution and lower frame rates for the acquisition of the 3D WSS in a reasonable measurement time of only 35 minutes. This enabled the in vivo assessment of all relevant hemodynamic parameters related to atherosclerosis development and progression in one experimental session. This method was validated in healthy wild type and atherosclerotic Apoe-/- mice, indicating no differences in robustness between pathological and healthy mice. The heterogeneous distribution of plaque development and arterial stiffening in atherosclerosis [10, 12], however, points out the importance of local PWV measurements. Therefore, future studies should focus on the 3D acquisition of the local PWV in the murine aortic arch based on the presented method, in order to enable spatially resolved correlations of local arterial stiffness with other hemodynamic parameters and plaque composition. In Chapter 3, the previously established methods were used for the investigation of changing aortic hemodynamics during ageing and atherosclerosis in healthy wild type and atherosclerotic Apoe-/- mice using the previously established methods [4, 16] based on high-resolution 4D-flow MRI. In this work, serial measurements of healthy and atherosclerotic mice were conducted to track all changes in hemodynamics in the complete aortic arch over time. Moreover, spatially resolved 2D projection maps of WSS and OSI of the complete aortic arch were generated. This important feature allowed for the pixel-wise statistical analysis of inter- and intragroup hemodynamic changes over time and most importantly - at a glance. The study revealed converse differences of local hemodynamic profiles in healthy WT and atherosclerotic Apoe-/- mice, with decreasing longWSS and increasing OSI, while showing constant PWV in healthy mice and increasing longWSS and decreasing OSI, while showing increased PWV in diseased mice. Moreover, spatially resolved correlations between WSS, PWV, plaque and vessel wall characteristics were enabled, giving detailed insights into coherences between hemodynamics and plaque composition. Here, the circWSS was identified as a potential marker of plaque size and composition in advanced atherosclerosis. Moreover, correlations with PWV values identified the maximum radStrain could serve as a potential marker for vascular elasticity. This study demonstrated the feasibility and utility of high-resolution 4D flow MRI to spatially resolve, visualize and analyze statistical differences in all relevant hemodynamic parameters over time and between healthy and diseased mice, which could significantly improve our understanding of plaque progression towards vulnerability. In future studies the relation of vascular elasticity and radial strain should be further investigated and validated with local PWV measurements and CFD. Moreover, the 2D histological datasets were not reflecting the 3D properties and regional characteristics of the atherosclerotic plaques. Therefore, future studies will include 3D plaque volume and composition analysis like morphological measurements with MRI or light-sheet microscopy to further improve the analysis of the relationship between hemodynamics and atherosclerosis. Chapter 4 aimed at the description and investigation of hemodynamics in early stages of atherosclerosis. Moreover, this study included measurements of hemodynamics at baseline levels in healthy WT and atherosclerotic mouse models. Due to the lack of hemodynamic-related studies in Ldlr-/- mice, which are the most used mouse models in atherosclerosis research together with the Apoe-/- mouse model, this model was included in this study to describe changing hemodynamics in the aortic arch at baseline levels and during early atherosclerosis development and progression for the first time. In this study, distinct differences in aortic geometries of these mouse models at baseline levels were described for the first time, which result in significantly different flow- and WSS profiles in the Ldlr-/- mouse model. Further basal characterization of different parameters revealed only characteristic differences in lipid profiles, proving that the geometry is highly influencing the local WSS in these models. Most interestingly, calculation of the atherogenic index of plasma revealed a significantly higher risk in Ldlr-/- mice with ongoing atherosclerosis development, but significantly greater plaque areas in the aortic arch of Apoe-/- mice. Due to the given basal WSS and OSI profile in these two mouse models - two parameters highly influencing plaque development and progression - there is evidence that the regional plaque development differs between these mouse models during very early atherogenesis. Therefore, future studies should focus on the spatiotemporal evaluation of plaque development and composition in the three defined aortic regions using morphological measurements with MRI or 3D histological analyses like LSFM. Moreover, this study offers an excellent basis for future studies incorporating CFD simulations, analyzing the different measured parameter combinations (e.g., aortic geometry of the Ldlr-/- mouse with the lipid profile of the Apoe-/- mouse), simulating the resulting plaque development and composition. This could help to understand the complex interplay between altered hemodynamics, serum lipids and atherosclerosis and significantly improve our basic understanding of key factors initiating atherosclerosis development. Chapter 5 describes the establishment of a tissue-engineered artery model, which is based on native, decellularized porcine carotid artery scaffolds, cultured in a MRI-suitable bioreactor-system [23] for the investigation of hemodynamic-related atherosclerosis development in a controllable manner, using the previously established methods for WSS and PWV assessment [4, 16]. This in vitro artery model aimed for the reduction of animal experiments, while simultaneously offering a simplified, but completely controllable physical and biological environment. For this, a very fast and gentle decellularization protocol was established in a first step, which resulted in porcine carotid artery scaffolds showing complete acellularity while maintaining the extracellular matrix composition, overall ultrastructure and mechanical strength of native arteries. Moreover, a good cellular adhesion and proliferation was achieved, which was evaluated with isolated human blood outgrowth endothelial cells. Most importantly, an MRI-suitable artery chamber was designed for the simultaneous cultivation and assessment of high-resolution 4D hemodynamics in the described artery models. Using high-resolution 4D-flow MRI, the bioreactor system was proven to be suitable to quantify the volume flow, the two components of the WSS and the radStrain as well as the PWV in artery models, with obtained values being comparable to values found in literature for in vivo measurements. Moreover, the identification of first atherosclerotic processes like intimal thickening is achievable by three-dimensional assessment of the vessel wall morphology in the in vitro models. However, one limitation is the lack of a medial smooth muscle cell layer due to the dense ECM. Here, the utilization of the laser-cutting technology for the generation of holes and / or pits on a microscale, eventually enabling seeding of the media with SMCs showed promising results in a first try and should be further investigated in future studies. Therefore, the proposed artery model possesses all relevant components for the extension to an atherosclerosis model which may pave the way towards a significant improvement of our understanding of the key mechanisms in atherogenesis. Chapter 6 describes the development of an easy-to-prepare, low cost and fully customizable artery model based on biomaterials. Here, thermoresponsive sacrificial scaffolds, processed with the technique of MEW were used for the creation of variable, biomimetic shapes to mimic the geometric properties of the aortic arch, consisting of both, bifurcations and curvatures. After embedding the sacrificial scaffold into a gelatin-hydrogel containing SMCs, it was crosslinked with bacterial transglutaminase before dissolution and flushing of the sacrificial scaffold. The hereby generated channel was subsequently seeded with ECs, resulting in an easy-to-prepare, fast and low-cost artery model. In contrast to the native artery model, this model is therefore more variable in size and shape and offers the possibility to include smooth muscle cells from the beginning. Moreover, a custom-built and highly adaptable perfusion chamber was designed specifically for the scaffold structure, which enabled a one-step creation and simultaneously offering the possibility for dynamic cultivation of the artery models, making it an excellent basis for the development of in vitro disease test systems for e.g., flow-related atherosclerosis research. Due to time constraints, the extension to an atherosclerosis model could not be achieved within the scope of this thesis. Therefore, future studies will focus on the development and validation of an in vitro atherosclerosis model based on the proposed bi- and three-layered artery models. In conclusion, this thesis paved the way for a fast acquisition and detailed analyses of changing hemodynamics during atherosclerosis development and progression, including spatially resolved analyses of all relevant hemodynamic parameters over time and in between different groups. Moreover, to reduce animal experiments, while gaining control over various parameters influencing atherosclerosis development, promising artery models were established, which have the potential to serve as a new platform for basic atherosclerosis research.}, subject = {H{\"a}modynamik}, language = {en} } @phdthesis{He2024, author = {He, Feng}, title = {Drug Discovery based on Oxidative Stress and HDAC6 for Treatment of Neurodegenerative Diseases}, doi = {10.25972/OPUS-25349}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-253497}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Most antioxidants reported so far only achieved limited success in AD clinical trials. Growing evidences suggest that merely targeting oxidative stress will not be sufficient to fight AD. While multi-target directed ligands could synergistically modulate different steps in the neurodegenerative process, offering a promising potential for treatment of this complex disease. Fifteen target compounds have been designed by merging melatonin and ferulic acid into the cap group of a tertiary amide HDAC6 inhibitor. Compound 10b was screened as the best hybrid molecule exhibit potent HDAC6 inhibition and potent antioxidant capacity. Compound 10b also alleviated LPS-induced microglia inflammation and led to a switch from neurotoxic M1 to the neuroprotective M2 microglial phenotype. Moreover, compound 10b show pronounced attenuation of spatial working memory and long-term memory damage in an in vivo AD mouse model. Compound 10b can be a potentially effective drug candidate for treatment of AD and its druggability worth to be further studied. We have designed ten novel neuroprotectants by hybridizing with several common antioxidants, including ferulic acid, melatonin, lipoic acid, and trolox. The trolox hybrid compound exhibited the most potent neuroprotective effects in multiple neuroprotection assays. Besides, we identified the synergistic effects between trolox and vitamin K derivative, and our trolox hybrid compound showed comparable neuroprotection with the mixture of trolox and vitamin K derivative. We have designed and synthesized 24 quinone derivatives based on five kinds of different quinones including ubiquinone, 2,3,5-trimethyl-1,4-benzoquinone, memoquin, thymoquinone, and anthraquinone. Trimethylbenzoquinone and thymoquinone derivatives showed more potent neuroprotection than other quinones in oxytosis assay. Therefore, trimethylbenzoquinone and thymoquinone derivatives can be used as lead compounds for further mechanism study and drug discovery for treatment of neurodegenerative disease. We designed a series of photoswitchable HDAC inhibitors, which could be effective molecular tools due to the high spatial and temporal resolution. In total 23 target compounds were synthesized and photophysicochemically characterized. Azoquinoline-based compounds possess more thermally stable cis-isomers in buffer solution, which were further tested in enzyme-based HDAC inhibition assay. However, none of those tested compounds show significant differences in activities between trans-isomers and corresponding cis-isomers.}, subject = {Alzheimerkrankheit}, language = {en} } @phdthesis{XavierdeSouza2024, author = {Xavier de Souza, Aline}, title = {Ecophysiological adaptations of the cuticular water permeability within the Solanaceae family}, doi = {10.25972/OPUS-22539}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225395}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The cuticle, a complex lipidic layer synthesized by epidermal cells, covers and protects primary organs of all land plants. Its main function is to avoid plant desiccation by limiting non-stomatal water loss. The cuticular properties vary widely among plant species. So far, most of the cuticle-related studies have focused on a limited number of species, and studies addressing phylogenetically related plant species are rare. Moreover, comparative studies among organs from the same plant species are still scarce. Thus, this study focus on organ-specificities of the cuticle within and between plant species of the Solanaceae family. Twenty-seven plant species of ten genera, including cultivated and non- cultivated species, were investigated to identify potential cuticular similarities. Structural, chemical and functional traits of fully expanded leaves, inflated fruiting calyces, and ripe fruits were analyzed. The surface morphology was investigated by scanning electron microscopy. Leaves were mainly amphistomatic and covered by an epicuticular wax film. The diversity and distribution of trichomes varied among species. Only the leaves of S. grandiflora were glabrous. Plant species of the Leptostemonum subgenus had numerous prickles and non-glandular stellate trichomes. Fruits were stomata-free, except for S. muricatum, and a wax film covered their surface. Last, lenticel- like structures and remaining scars of broken trichomes were found on the surface of some Solanum fruits. Cuticular water permeability was used as indicators of the cuticular transpiration barrier efficiency. The water permeability differed among plant species, organs and fruit types with values ranging up to one hundred-fold. The minimum leaf conductance ranged from 0.35 × 10-5 m s-1 in S. grandiflora to 31.54 × 10-5 m s-1 in S. muricatum. Cuticular permeability of fruits ranged from 0.64 × 10-5 m s-1 in S. dulcamara (fleshy berry) to 34.98 × 10-5 m s-1 in N. tabacum (capsule). Generally, the cuticular water loss of dry fruits was about to 5-fold higher than that of fleshy fruits. Interestingly, comparisons between cultivated and non-cultivated species showed that wild species have the most efficient cuticular transpiration barrier in leaves and fruits. The average permeability of leaves and fruits of wild plant species was up to three-fold lower in comparison to the cultivated ones. Moreover, ripe fruits of P. ixocarpa and P. peruviana showed two-times lower cuticular transpiration when enclosed by the inflated fruiting calyx. The cuticular chemical composition was examined using gas chromatography. Very-long-chain aliphatic compounds primarily composed the cuticular waxes, being mostly dominated by n- alkanes (up to 80\% of the total wax load). Primary alkanols, alkanoic acids, alkyl esters and branched iso- and anteiso-alkanes were also frequently found. Although in minor amounts, sterols, pentacyclic triterpenoids, phenylmethyl esters, coumaric acid esters, and tocopherols were identified in the cuticular waxes. Cuticular wax coverages highly varied in solanaceous (62- fold variation). The cuticular wax load of fruits ranged from 0.55 μg cm-2 (Nicandra physalodes) to 33.99 μg cm-2 (S. pennellii), whereas the wax amount of leaves varied from 0.90 μg cm-2 (N. physalodes) to 28.42 μg cm-2 (S. burchellii). Finally, the wax load of inflated fruiting calyces ranged from 0.56 μg cm-2 in P. peruviana to 2.00 μg cm-2 in N. physalodes. For the first time, a comparative study on the efficiency of the cuticular transpiration barrier in different plant organs of closely related plant species was conducted. Altogether, the cuticular chemical variability found in solanaceous species highlight species-, and organ-specific wax biosynthesis. These chemical variabilities might relate to the waterproofing properties of the plant cuticle, thereby influencing leaf and fruit performances. Additionally, the high cuticular water permeabilities of cultivated plant species suggest a potential existence of a trade-off between fruit organoleptic properties and the efficiency of the cuticular transpiration barrier. Last, the high cuticular water loss of the solanaceous dry fruits might be a physiological adaptation favouring seed dispersion.}, subject = {Kutikula}, language = {en} } @phdthesis{Neitz2024, author = {Neitz, Hermann}, title = {Hydrophobic recognition motifs in functionalized DNA}, doi = {10.25972/OPUS-34838}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348382}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In w{\"a}ssriger Umgebung spielen hydrophobe Wechselwirkungen eine wichtige Rolle f{\"u}r die DNA. Die Einf{\"u}hrung von Modifikationen, die auf hydrophoben aromatischen Einheiten basieren, kann die Erkennung und Reaktivit{\"a}t von funktionellen Gruppen in der DNA steuern. Modifikationen k{\"o}nnen durch ein k{\"u}nstliches R{\"u}ckgrat oder in Form einer Erweiterung der Nukleobasen eingebracht werden und so zu zus{\"a}tzlichen Eigenschaften der DNA f{\"u}hren. Diese Dissertation befasst sich mit der Verwendung von hydrophoben Einheiten zur Funktionalisierung von DNA. Im ersten Teil der Arbeit wurde das Tolanmotiv (Diphenylacetylen) in Kombination mit dem acyclischen R{\"u}ckgrat von GNA und BuNA verwendet, um Erkennungseinheiten im DNA-Kontext zu erzeugen. Die gezielte Fluorierung der aromatischen Ringe des Tolan-Bausteins bildete die Grundlage f{\"u}r eine supramolekulare Sprache, die auf Aren-Fluoroaren-Wechselwirkungen basiert. Die spezifische Erkennung wurde mittels thermodynamischer, kinetischer und NMR-spektroskopischer Methoden untersucht. Im zweiten Teil der Arbeit wurden Desoxyuridin-Derivate mit einer hydrophoben aromatischen Modifikation hergestellt und in die DNA-Doppelhelix eingebaut. Die Bestrahlung mit UV-Licht f{\"u}hrte zu einer [2+2]-Cycloaddition zwischen zwei modifizierten Nukleosiden in der DNA. Das Reaktionsprodukt wurde strukturell charakterisiert und die Reaktion in verschiedenen biochemischen und nanotechnologischen DNA-Anwendungen eingesetzt.}, subject = {Supramolekulare Chemie}, language = {en} } @phdthesis{Wenderoth2024, author = {Wenderoth, Sarah}, title = {Synthesis and characterization of shear stress indicator supraparticles}, doi = {10.25972/OPUS-35281}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352819}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The detection of smallest mechanical loads plays an increasingly important role in many areas of advancing automation and manufacturing technology, but also in everyday life. In this doctoral thesis, various microparticle systems were developed that are able to indicate mechanical shear stress via simple mechanisms. Using a toolbox approach, these systems can be spray-dried from various nanoscale primary particles (silica and iron oxide) to micrometer-sized units, so-called supraparticles. By varying the different building blocks and in combination with different dyes, a new class of mechanochromic shear stress indicators was developed by constructing hierarchically structured core-shell supraparticles that can indicate mechanical stress via an easily detectable color change. Three different mechanisms can be distinguished. If a signal becomes visible only by a mechanical load, it is a turn-on indicator. In the opposite case, the turn-off indicator, the signal is switched off by a mechanical load. In the third mechanism, the color-change indicator, the color changes as a result of a mechanical load. In principle, these indicators can be used in two different ways. First, they can be incorporated into a coating as an additive. These coatings can be applied to a wide range of products, including food packaging, medical devices, and generally any sensitive surface where mechanical stress, such as scratches, is difficult to detect but can have serious consequences. Second, these shear stress indicators can also be used directly in powder form and for example then applied in 3D-printing or in ball mills. A total of six different shear stress indicators were developed, three of which were used as additives in coatings and three were applied in powder form. Depending on their composition, these indicators were readout by fluorescence, UV-Vis or Magnetic Particle Spectroscopy. The development of these novel shear stress indicator supraparticles were successfully combined molecular chemistry with the world of nano-objects to develop macroscopic systems that can enable smart and communicating materials to indicate mechanical stress in a variety of applications.}, subject = {Nanopartikel}, language = {en} } @phdthesis{Peindl2024, author = {Peindl, Matthias}, title = {Refinement of 3D lung cancer models for automation and patient stratification with mode-of-action studies}, doi = {10.25972/OPUS-31069}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310693}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Lung cancer is the main cause of cancer-related deaths worldwide. Despite the availability of several targeted therapies and immunotherapies in the clinics, the prognosis for lung cancer remains poor. A major problem for the low benefit of these therapies is intrinsic and acquired resistance, asking for pre-clinical models for closer investigation of predictive biomarkers for refined personalized medicine and testing of possible combination therapies as well as novel therapeutic approaches to break resistances. One third of all lung adenocarcinoma harbor mutations in the KRAS gene, of which 39 \% are transitions from glycine to cysteine in codon 12 (KRASG12C). Being considered "undruggable" in previous decades, KRASG12C-inhibitors now paved the way into the standard-of-care for lung adenocarcinoma treatment in the clinics. Still, the overall response rates as well as overall survival of patients treated with KRASG12C-inhibitors are sobering. Therefore, 3D KRASG12C-biomarker in vitro models were developed based on a decellularized porcine jejunum (SISmuc) using commercial and PDX-derived cell lines and characterized in regards of epithelial-mesenchymal-transition (EMT), stemness, proliferation, invasion and c-MYC expression as well as the sensitivity towards KRASG12C-inhibiton. The phenotype of lung tumors harboring KRAS mutations together with a c-MYC overexpression described in the literature regarding invasion and proliferation for in vivo models was well represented in the SISmuc models. A higher resistance towards targeted therapies was validated in the 3D models compared to 2D cultures, while reduced viability after treatment with combination therapies were exclusively observed in the 3D models. In the test system neither EMT, stemness nor the c-MYC expression were directly predictive for drug sensitivity. Testing of a panel of combination therapies, a sensitizing effect of the aurora kinase A (AURKA) inhibitor alisertib for the KRASG12C-inhibitor ARS-1620 directly correlating with the level of c-MYC expression in the corresponding 3D models was observed. Thereby, the capability of SISmuc tumor models as an in vitro test system for patient stratification was demonstrated, holding the possibility to reduce animal experiments. Besides targeted therapies the treatment of NSCLC with oncolytic viruses (OVs) is a promising approach. However, a lack of in vitro models to test novel OVs limits the transfer from bench to bedside. In this study, 3D NSCLC models based on the SISmuc were evaluated for their capability to perform efficacy and risk assessment of oncolytic viruses (OVs) in a pre-clinical setting. Hereby, the infection of cocultures of tumor cells and fibroblasts on the SISmuc with provided viruses demonstrated that in contrast to a wildtype herpes simplex virus 1 (HSV-1) based OV, the attenuated version of the OV exhibited specificity for NSCLC cells with a more advanced and highly proliferative phenotype, while fibroblasts were no longer permissive for infection. This approach introduced SISmuc tumor models as novel test system for in vitro validation of OVs. Finally, a workflow for validating the efficacy of anti-cancer therapies in 3D tumor spheroids was established for the transfer to an automated platform based on a two-arm-robot system. In a proof-of-concept process, H358 spheroids were characterized and treated with the KRASG12C-inhibitor ARS-1620. A time- and dose-dependent reduction of the spheroid area after treatment was defined together with a live/dead-staining as easy-to-perform and cost-effective assays for automated drug testing that can be readily performed in situ in an automated system.}, subject = {Krebs }, language = {en} } @phdthesis{Issler2024, author = {Issler, Kevin}, title = {Theory and simulation of ultrafast autodetachment dynamics and nonradiative relaxation in molecules}, doi = {10.25972/OPUS-35223}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352232}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In this thesis, theoretical approaches for the simulation of electron detachment processes in molecules following vibrational or electronic excitation are developed and applied. These approaches are based on the quantum-classical surface-hopping methodology, in which nuclear motion is treated classically as an ensemble of trajectories in the potential of quantum-mechanically described electronic degrees of freedom.}, subject = {Theoretische Chemie}, language = {en} } @phdthesis{Schuerger2024, author = {Sch{\"u}rger, Peter}, title = {Information-Theoretical Studies on Time-Dependent Quantum Systems}, doi = {10.25972/OPUS-35221}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352215}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In this thesis, we apply the information-theoretic approach in the context of quantum dynamics and wave packet motion: Information-theoretic measures are calculated from position and momentum densities, which are obtained from time-dependent quantum wave functions. The aim of this thesis is to benchmark, analyze and interpret these quantities and relate their features to the wave packet dynamics. Firstly, this is done for the harmonic oscillator (HO) with and without static disorder. In the unperturbed HO, the analytical study of coherent and squeezed states reveals time-dependent entropy expressions related to the localization of the wave function. In the disordered HO, entropies from classical and quantum dynamics are compared for short and long times. In the quantum case, imprints of wave packet revivals are found in the entropy. Then, the energy dependence of the entropy for very long times is discussed. Secondly, this is donefor correlated electron-nuclear motion. Here, entropies derived from the total, electronic and nuclear density, respectively, are calculated in position and momentum space for weak and strong adiabatic electronic coupling. The correlation between electron and nucleus is investigated using different correlation measures, where some of these functions are sensitive to the nodal structure of the wave function. An analytic ansatz to interpret the information-theoretical quantities is applied as well.}, subject = {St{\"o}rungstheorie}, language = {en} } @phdthesis{PenaMosca2024, author = {Pe{\~n}a Mosca, Mar{\´i}a Josefina}, title = {Local regulation of T-cell immunity in the intestinal mucosa}, doi = {10.25972/OPUS-35266}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352665}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {After priming in Peyer's patches (PPs) and mesenteric lymph nodes (mLN) T- cells infiltrate the intestine through lymphatic draining and homing through the bloodstream. However, we found that in mouse models of acute graft-versus-host disease (GvHD), a subset of alloreactive T-cells directly migrates from PPs to the adjacent intestinal lamina propria (LP), bypassing the normal lymphatic drainage and vascular trafficking routes. Notably, this direct migration occurred in irradiated and unirradiated GvHD models, indicating that irradiation is not a prerequisite for this observed behavior. Next, we established a method termed serial intravascular staining (SIVS) in mouse models to systematically investigate the trafficking and migration of donor T- cells in the early stages of acute GvHD initiation. We found that the direct migration of T-cells from PPs to LP resulted in faster recruitment of cells after allogeneic hematopoietic cell transplantation (allo-HCT). These directly migrating T-cells were found to be in an activated and proliferative state, exhibiting a TH1/TH17-like phenotype and producing cytokines such as IFN-γ and TNF-α. Furthermore, we observed that the directly migrating alloreactive T-cells expressed specific integrins (α4+, αE+) and chemokine receptors (CxCR3+, CCR5+, and CCR9+). Surprisingly, blocking these integrins and chemokine-coupled receptors did not hinder the direct migration of T- cells from PPs to LP, suggesting the involvement of alternative mechanisms. Previous experiments ruled out the involvement of S1PR1 and topographical features of macrophages, leading us to hypothesize that mediators of cytoskeleton reorganization, such as Coro1a, Dock2, or Cdc42, may play a role in this unique migration process. Additionally, we observed that directly migrating T-cells created a local inflammatory microenvironment, which attracts circulating T-cells. Histological analysis confirmed that alloreactive PPs-derived T-cells and bloodborne T-cells colocalized. We employed two experimental approaches, including either photoconversion of T-cells in PPs or direct transfer of activated T-cells into the vasculature, to demonstrate this colocalization. We hypothesize that cytokines released by migrating T-cells, such as IFN-γ and TNF-α, may play a role in recruiting T-cells from the vasculature, as inhibiting chemokine-coupled receptors did not impair recruitment.}, subject = {T-Lymphozyt}, language = {en} } @phdthesis{Herok2024, author = {Herok, Christoph}, title = {Quantum Chemical Exploration of Potential Energy Surfaces: Reaction Cycles and Luminescence Phenomena}, doi = {10.25972/OPUS-35218}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352185}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {This work aims at elucidating chemical processes involving homogeneous catalysis and photo-physical relaxation of excited molecules in the solid state. Furthermore, compounds with supposedly small singlet-triplet gaps and therefore biradicaloid character are investigated with respect to their electro-chemical behavior. The work on hydroboration catalysis via a reduced 9,10-diboraanthracene (DBA) was preformed in collaboration with the Wagner group in Frankfurt, more specifically Dr. Sven Prey, who performed all laboratory experiments. The investigation of delayed luminescence properties in arylboronic esters in their solid state was conducted in collaboration with the Marder group in W{\"u}rzburg. The author of this work took part in the synthesis of the investigated compounds while being supervised by Dr. Zhu Wu. The final project was a collaboration with the group of Anukul Jana from Hyderabad, India who provided the experimental data.}, subject = {Simulation}, language = {en} } @phdthesis{Weisert2024, author = {Weisert, Nadine}, title = {Characterization of telomere-associated proteins in \(Trypanosoma\) \(brucei\)}, doi = {10.25972/OPUS-35273}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352732}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The unicellular pathogen Trypanosoma brucei is the causative agent of African trypanosomiasis, an endemic disease prevalent in sub-Saharan Africa. Trypanosoma brucei alternates between a mammalian host and the tsetse fly vector. The extracellular parasite survives in the mammalian bloodstream by periodically exchanging their ˈvariant surface glycoproteinˈ (VSG) coat to evade the host immune response. This antigenic variation is achieved through monoallelic expression of one VSG variant from subtelomeric ˈbloodstream form expression sitesˈ (BES) at a given timepoint. During the differentiation from the bloodstream form (BSF) to the procyclic form (PCF) in the tsetse fly midgut, the stage specific surface protein is transcriptionally silenced and replaced by procyclins. Due to their subtelomeric localization on the chromosomes, VSG transcription and silencing is partly regulated by homologues of the mammalian telomere complex such as TbTRF, TbTIF2 and TbRAP1 as well as by ˈtelomere-associated proteinsˈ (TelAPs) like TelAP1. To gain more insights into transcription regulation of VSG genes, the identification and characterization of other TelAPs is critical and has not yet been achieved. In a previous study, two biochemical approaches were used to identify other novel TelAPs. By using ˈco-immunoprecipitationˈ (co-IP) to enrich possible interaction partners of TbTRF and by affinity chromatography using telomeric repeat oligonucleotides, a listing of TelAP candidates has been conducted. With this approach TelAP1 was identified as a novel component of the telomere complex, involved in the kinetics of transcriptional BES silencing during BSF to PCF differentiation. To gain further insights into the telomere complex composition, other previously enriched proteins were characterized through a screening process using RNA interference to deplete potential candidates. VSG expression profile changes and overall proteomic changes after depletion were analyzed by mass spectrometry. With this method, one can gain insights into the functions of the proteins and their involvement in VSG expression site regulation. To validate the interaction of proteins enriched by co-IP with TbTRF and TelAP1 and to identify novel interaction proteins, I performed reciprocal affinity purifications of the four most promising candidates (TelAP2, TelAP3, PPL2 and PolIE) and additionally confirmed colocalization of two candidates with TbTRF via immunofluorescence (TelAP2, TelAP3). TelAP3 colocalizes with TbTRF and potentially interacts with TbTRF, TbTIF2, TelAP1 and TelAP2, as well as with two translesion polymerases PPL2 and PolIE in BSF. PPL2 and PolIE seem to be in close contact to each other at the telomeric ends and fulfill different roles as only PolIE is involved in VSG regulation while PPL2 is not. TelAP2 was previously characterized to be associated with telomeres by partially colocalizing with TbTRF and cells show a VSG derepression phenotype when the protein was depleted. Here I show that TelAP2 interacts with the telomere-binding proteins TbTRF and TbTIF2 as well as with the telomere-associated protein TelAP1 in BSF and that TelAP2 depletion results in a loss of TelAP1 colocalization with TbTRF in BSF. In conclusion, this study demonstrates that characterizing potential TelAPs is effective in gaining insights into the telomeric complex's composition and its role in VSG regulation in Trypanosoma brucei. Understanding these interactions could potentially lead to new therapeutic targets for combatting African trypanosomiasis.}, subject = {Telomer }, language = {en} } @phdthesis{Nadernezhad2024, author = {Nadernezhad, Ali}, title = {Engineering approaches in biofabrication of vascularized structures}, doi = {10.25972/OPUS-34589}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-345892}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Biofabrication technologies must address numerous parameters and conditions to reconstruct tissue complexity in vitro. A critical challenge is vascularization, especially for large constructs exceeding diffusion limits. This requires the creation of artificial vascular structures, a task demanding the convergence and integration of multiple engineering approaches. This doctoral dissertation aims to achieve two primary objectives: firstly, to implement and refine engineering methods for creating artificial microvascular structures using Melt Electrowriting (MEW)-assisted sacrificial templating, and secondly, to deepen the understanding of the critical factors influencing the printability of bioink formulations in 3D extrusion bioprinting. In the first part of this dissertation, two innovative sacrificial templating techniques using MEW are explored. Utilizing a carbohydrate glass as a fugitive material, a pioneering advancement in the processing of sugars with MEW with a resolution under 100 microns was made. Furthermore, by introducing the "print-and-fuse" strategy as a groundbreaking method, biomimetic branching microchannels embedded in hydrogel matrices were fabricated, which can then be endothelialized to mirror in vivo vascular conditions. The second part of the dissertation explores extrusion bioprinting. By introducing a simple binary bioink formulation, the correlation between physical properties and printability was showcased. In the next step, employing state-of-the-art machine-learning approaches revealed a deeper understanding of the correlations between bioink properties and printability in an extended library of hydrogel formulations. This dissertation offers in-depth insights into two key biofabrication technologies. Future work could merge these into hybrid methods for the fabrication of vascularized constructs, combining MEW's precision with fine-tuned bioink properties in automated extrusion bioprinting.}, subject = {3D-Druck}, language = {en} } @phdthesis{Weber2024, author = {Weber, Justus C.}, title = {Development and preclinical assessment of ROR2-specific CAR-T cells for the treatment of clear cell renal cell carcinoma and multiple myeloma}, doi = {10.25972/OPUS-31039}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310399}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Adoptive immunotherapy using chimeric antigen receptor (CAR)-modified T cells is an effective treatment for hematological malignancies that are refractory to conventional chemotherapy. To address a wider variety of cancer entities, there is a need to identify and characterize additional target antigens for CAR-T cell therapy. The two members of the receptor tyrosine kinase-like orphan receptor family, ROR1 and ROR2, have been found to be overexpressed on cancer cells and to correlate with aggressive cancer phenotypes. Recently, ROR1-specific CAR-T cells have entered testing in phase I clinical trials, encouraging us to assess the suitability of ROR2 as a novel target for CAR-T cell therapy. To study the therapeutic potential of targeting ROR2 in solid and hematological malignancies, we selected two representative cancer entities with high unmet medical need: renal cell carcinoma and multiple myeloma. Our data show that ROR2 is commonly expressed on primary samples and cell lines of clear cell renal cell carcinoma and multiple myeloma. To study the efficacy of ROR2-specific CAR T cell therapy, we designed two CAR constructs with 10-fold binding affinity differences for the same epitope of ROR2. We found both cell products to exhibit antigen-specific anti-tumor reactivity in vitro, including tumor cell lysis, secretion of the effector cytokines interleukin-2 (IL-2) and interferon-gamma (IFNγ), and T cell proliferation. In vivo studies revealed ROR2 specific CAR-T cells to confer durable responses, significant survival benefits and long-term persistence of CAR-expressing T cells. Overall, there was a trend towards more potent anti-tumor efficacy upon treatment with T cells that expressed the CAR with higher affinity for ROR2, both in vitro and in vivo. We performed a preclinical safety and toxicology assessment comprising analyses of ROR2 expression in healthy human and murine tissues, cross-reactivity, and adoptive T cell transfer in immunodeficient mice. We found ROR2 expression to be conserved in mice, and low-level expression was detectable in the male and female reproductive system as well as parts of the gastrointestinal tract. CAR-T cells targeting human ROR2 were found to elicit similarly potent reactivity upon recognition of murine ROR2. In vivo analyses showed transient tissue-specific enrichment and activation of ROR2-specific CAR-T cells in organs with high blood circulation, such as lung, liver, or spleen, without evidence for clinical toxicity or tissue damage as determined by histological analyses. Furthermore, we humanized the CAR binding domain of ROR2-specific CAR-T cells to mitigate the risk of adverse immune reactions and concomitant CAR-T cell rejection. Functional analyses confirmed that humanized CARs retained their specificity and functionality against ROR2-positive tumor cells in vitro. In summary, we show that ROR2 is a prevalent target in RCC and MM, which can be addressed effectively with ROR2-specific CAR-T cells in preclinical models. Our preliminary toxicity studies suggest a favorable safety profile for ROR2-specific CAR-T cells. These findings support the potential to develop ROR2-specific CAR-T cells clinically to obtain cell products with broad utility.}, subject = {CAR-T-Zell-Therapie}, language = {en} } @phdthesis{Pres2024, author = {Pres, Sebastian}, title = {Detection of a plasmon-polariton quantum wave packet by coherent 2D nanoscopy}, doi = {10.25972/OPUS-34824}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348242}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Plasmonic nanostructures are considered promising candidates for essential components of integrated quantum technologies because of their ability to efficiently localize broad-band electromagnetic fields on the nanoscale. The resulting local near field can be understood as a spatial superposition of spectrally different plasmon-polariton modes due to the spectrally broad optical excitation, and thus can be described as a classical wave packet. Since plasmon polaritons, in turn, can transmit and receive non-classical light states, the exciting question arises to what extent they have to be described as quantum mechanical wave packets, i.e. as a superposition of different quantum states. But how to probe, characterize and eventually manipulate the quantum state of such plasmon polaritons? Up to now, probing at room temperatures relied completely on analyzing quantum optical properties of the corresponding in-going and out-going far-field photon modes. However, these methods so far only allow a rather indirect investigation of the plasmon-polariton quantum state by means of transfer into photons. Moreover, these indirect methods lack spatial resolution and therefore do not provide on-site access to the plasmon-polariton quantum state. However, since the spectroscopic method of coherent two-dimensional (2D) nanoscopy offers the capability to follow the plasmon- polariton quantum state both in Hilbert space and in space and time domain a complete characterization of the plasmon polariton is possible. In this thesis a versatile coherent 2D nanoscopy setup is presented combining spectral tunability and femtosecond time resolution with spatial resolution on the nanometer scale due to the detection of optically excited nonlinear emitted electrons via photoemission electron microscopy (PEEM). Optical excitation by amplitude- and phase-shaped, systematically-modified and interferometric-stable multipulse sequences is realized, and characterized via Fourier-transform spectral interferometry (FTSI). This linear technique enables efficient data acquisition in parallel to a simultaneously performed experiment. The full electric-field reconstruction of every generated multipulse sequence is used to analyze the effect of non-ideal pulse sequences on the two-dimensional spectral data of population-based multidimensional spectroscopy methods like, e.g., the coherent 2D nanoscopy applied in this thesis. Investigation of the spatially-resolved nonlinear electron emission yield from plasmonic gold nanoresonators by coherent 2D nanoscopy requires a quasi-particle treatment of the addressed plasmon-polariton mode and development of a quantum model to adequately describe the plasmon-assisted multi-quantum electron emission from nanostructures. Good agreement between simulated and experimental data enables to connect certain spectral features to superpositions of non-adjacent plasmon-polariton quantum states, i.e, non-adjacent occupation-number states of the underlying quantized, harmonic oscillator, thus direct probing of the plasmon-polariton quantum wave packet at the location of the nanostructure. This is a necessary step to locally control and manipulate the plasmon-polariton quantum state and thus of general interest for the realization of nanoscale quantum optical devices.}, subject = {Coherent Multidimensional Spectroscopy}, language = {en} } @phdthesis{Ibrahim2024, author = {Ibrahim, Eslam Samir Ragab}, title = {Unraveling the function of the old yellow enzyme OfrA in \(Staphylococcus\) \(aureus\) stress response}, doi = {10.25972/OPUS-28960}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289600}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Biological systems are in dynamic interaction. Many responses reside in the core concepts of biological systems interplay (competition and cooperation). In infection situation, the competition between a bacterial system and a host is shaped by many stressors at spatial and temporal determinants. Reactive chemical species are universal stressors against all biological systems since they potentially damage the basic requirements of these systems (nucleic acids, proteins, carbohydrates, and lipids). Either produced endogenously or exogenously, reactive chemical species affect the survival of pathogens including the gram-positive Staphylococcus aureus (S. aureus). Therefore, bacteria developed strategies to overcome the toxicity of reactive species. S. aureus is a widely found opportunistic pathogen. In its niche, S. aureus is in permanent contact with surrounding microbes and host factors. Deciphering the deterministic factors in these interactions could facilitate pinpointing novel bacterial targets. Identifying the aforementioned targets is crucial to develop new strategies not only to kill the pathogenic organisms but also to enhance the normal flora to minimize the pathogenicity and virulence of potential pathogens. Moreover, targeting S. aureus stress response can be used to overcome bacterial resistance against host-derived factors. In this study, I identify a novel S. aureus stress response factor against reactive electrophilic, oxygen, and hypochlorite species to better understand its resilience as a pathogen. Although bacterial stress response is an active research field, gene function is a current bottleneck in characterizing the understudied bacterial strategies to mediate stress conditions. I aimed at understanding the function of a novel protein family integrated in many defense systems of several biological systems. In bacteria, fungi, and plants, old yellow enzymes (OYEs) are widely found. Since the first isolation of the yellow flavoprotein, OYEs are used as biocatalysts for decades to reduce activated C=C bonds in α,β-unsaturated carbonyl compounds. The promiscuity of the enzymatic catalysis is advantageous for industrial applications. However, the physiological function of OYEs, especially in bacteria, is still puzzling. Moreover, the relevance of the OYEs in infection conditions remained enigmatic.   Here, I show that there are two groups of OYEs (OYE flavin oxidoreductase, OfrA and OfrB) that are encoded in staphylococci and some firmicutes. OfrA (SAUSA300_0859) is more conserved than OfrB (SAUSA300_0322) in staphylococci and is a part of the staphylococcal core genome. A reporter system was established to report for ofrA in S. aureus background. The results showed that ofrA is induced under electrophilic, oxidative, and hypochlorite stress. OfrA protects S. aureus against quinone, methylglyoxal, hydrogen peroxide, and hypochlorite stress. Additionally, the results provide evidence that OfrA supports thiol-dependent redox homeostasis. At the host-pathogen interface, OfrA promotes S. aureus fitness in murine macrophage cell line. In whole human blood, OfrA is involved in S. aureus survival indicating a potential clinical relevance to bacteraemia. In addition, ofrA mutation affects the production of the virulence factor staphyloxanthin via the upper mevalonate pathway. In summary, decoding OfrA function and its proposed mechanism of action in S. aureus shed the light on a conserved stress response within multiple organisms.}, subject = {Staphylococcus aureus}, language = {en} } @phdthesis{Kopic2024, author = {Kopic, Eva}, title = {On the physiological role of post-translational regulation of the \(Arabidopsis\) guard cell outward rectifying potassium channel GORK}, doi = {10.25972/OPUS-34880}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348806}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Das streng regulierte Gleichgewicht zwischen CO2-Aufnahme und Transpiration ist f{\"u}r Pflanzen essentiell und h{\"a}ngt von kontrollierten Turgor{\"a}nderungen ab, die durch die Aktivit{\"a}t verschiedener Anionen- und Kationenkan{\"a}le verursacht werden. Diese Kan{\"a}le sind Teil von Signalkaskaden, die z. B. durch Phytohormone wie ABA (Abscisins{\"a}ure) und JA (Jasmonat) ausgel{\"o}st werden, die beide bei Trockenstress in den Schließzellen wirken. Dar{\"u}ber hinaus ist bekannt, dass JA an der Reaktion der Pflanze auf Pathogenbefall oder Verwundung beteiligt ist. GORK (guard cell outward rectifying K+ channel) ist der einzige bekannte, ausw{\"a}rts gleichrichtende K+-Kanal in Schließzellen und somit f{\"u}r den K+-Efflux beim Schließen der Stomata verantwortlich. Im Rahmen dieser Arbeit konnte nachgewiesen werden, dass GORK ein wesentlicher Bestandteil des JA-induzierten Stomatschlusses ist. Dies gilt f{\"u}r beide Ausl{\"o}ser, sowohl die Blattverwundung als auch die direkte Anwendung von JA. Patch-Clamp-Experimente an Protoplasten von Schließzellen untermauerten dieses Ergebnis, indem sie GORK-K+-Ausw{\"a}rtsstr{\"o}me als direktes Ziel von JA-Signalen entlarvten. Da bekannt ist, dass zytosolische Ca2+-Signale sowohl bei ABA- als auch bei JA-Signalen eine Rolle spielen, wurde die Interaktion von GORK mit Ca2+-abh{\"a}ngigen Kinasen untersucht. Eine antagonistische Regulation von GORK durch CIPK5-CBL1/9-Komplexe und ABI2 konnte durch DEVC (double electrode voltage clamp) sowie Protein-Protein-Interaktions-Experimente identifiziert und durch in-vitro Kinase-Assays untermauert werden. Patch-Clamp-Aufzeichnungen an Protoplasten von Schließzellen der cipk5-2 Funktions-Verlust-Mutante zeigten die Bedeutung von CIPK5 f{\"u}r den JA-induzierten Stomaschluss via Aktivierung von GORK. Die Interaktion verschiedener CDPKs (Ca2+-abh{\"a}ngige Proteinkinasen) mit GORK wurde ebenfalls untersucht. Neben der Ca2+-Signal{\"u}bertragung ist auch die Produktion von ROS (reaktive Sauerstoffspezies) f{\"u}r die ABA- und MeJA-Signal{\"u}bertragung von Bedeutung. In DEVC-Experimenten konnte ein reversibler Effekt von ROS auf die GORK-Kanalaktivit{\"a}t nachgewiesen werden, was ein Teil der Erkl{\"a}rung f{\"u}r diese ROS-Effekte bei ABA- und MeJA-Signalen sein k{\"o}nnte.}, subject = {Spalt{\"o}ffnung}, language = {en} } @phdthesis{Triyasmono2024, author = {Triyasmono, Liling}, title = {Development and Application of Quantitative \(^1\)H NMR Spectroscopy and Chemometrics for Quality Determination of Red Fruit (\(Pandanus\) \(conoideus\), Lam.) Oil}, doi = {10.25972/OPUS-30272}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302726}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {In this thesis, a new approach of a qNMR method has been investigated to demonstrate the reliability and importance of this method as an alternative solution for analyzing oil quality parameters, especially in RFO, which has particular characteristics (red color). This study also includes the chemometric evaluation of spectral data for authentication, visual grouping, and prediction of RFO quality based on the degree of unsaturation, FFA value, and unsaturated fatty acid content. The analytical measurement procedure of NMR spectroscopy begins with optimization of the analytical acquisition parameters, including effect of solvent, effect of sample concentration, selection of appropriate internal standards, determination of T1, and method validation. Furthermore, the results of the method development were interpreted to RFO samples evaluation, which began with determining the assignment of signal spectra for the determination of AV, SV, EV, and IV simultaneously with: the hydrolysis approach and standard addition of palmitic acid.}, subject = {NMR-Spektroskopie}, language = {en} } @phdthesis{Trinks2024, author = {Trinks, Nora Isabel}, title = {Super-resolution fluorescence microscopic visualization and analysis of interactions between human immune cells and \(Aspergillus\) \(fumigatus\)}, doi = {10.25972/OPUS-26640}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266407}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The mold Aspergillus fumigatus (A. fumigatus) is known as human pathogen and can cause life-threatening infections in humans with a weakened immune system. This is a known complication in patients receiving glucocorticoids, e.g. after hematopoietic stem cell transplantation or solid organ transplantation. Although research in the field of immune cell/fungus interaction has discovered key strategies how immune cells fight against infectious fungi, our knowledge is still incomplete. In order to develop effective treatment options against fungal infections, a detailed understanding of their interactions is crucial. Thus, visualization of immune cell and fungus is an excellent approach to gain further knowledge. For a detailed view of such interaction processes, a high optical resolution on nanometer scale is required. There is a variety of super resolution microscopy techniques, enabling fluorescence imaging beyond the diffraction limit. This work combines the use of three complementary super resolution microscopy techniques, in order to study immune cell/fungus interaction from different points of view. Aim of this work is the introduction of the recently invented imaging technique named expansion microscopy (ExM) for the study of immune cell/fungus interactions. The core aspect of this method is the physical magnification of the specimen, which increases the distance between protein structures that are close to each other and which can therefore be imaged separately. The simultaneous magnification of primary human natural killer (NK) cells and A. fumigatus hyphae was established in this work using ExM. Reorganization of cytoskeletal components of interacting NK cells was demonstrated here, by expansion of the immunological synapse (IS), formed between NK cells and A. fumigatus. In addition, reorganization of the microtubule-organizing center (MTOC) towards fungal hyphae and an accumulation of actin at the IS has been observed. Furthermore, ExM has been used to visualize lytic granules of NK cells after degranulation. After magnification of the specimen, lysosome associated protein 1 (LAMP1) was shown to surround perforin. In absence of the plasma membrane-exposed degranulation marker LAMP1, a "ring-shaped" structure was often observed for fluorescently labeled perforin. Volume calculation of lytic granules demonstrated the benefit of ExM. Compared to pre-expansion images, analyses of post-expansion images showed two volume distributions for degranulated and non-degranulated NK cells. In addition, this work emphasizes the importance of determining the expansion factor for a structure in each species, as variations of expansion factors have been observed. This factor, as well as possible sample distortions should be considered, when ExM is used in order to analyze the interaction between two species. A second focus of this work is the visualization of a chimeric antigen receptor (CAR), targeting an epitope on the cell wall of A. fumigatus. Structured illumination microscopy (SIM) revealed that the CAR is part of the immunological synapse of primary human CAR T cells and CAR-NK-92 cells. At the interaction site, an accumulation of the CAR was observed, as well as the presence of perforin. CAR accumulation at fungal hyphae was further demonstrated by automated live cell imaging of interacting CAR-NK-92 cells, expressing a fluorescent fusion protein. Additionally, the use of direct stochastic optical reconstruction microscopy (dSTORM) gave first insights in CAR expression levels on the basal membrane of CAR-NK-92 cells, with single molecule sensitivity. CAR cluster analyses displayed a heterogeneous CAR density on the basal membrane of transfected NK 92 cells. In summary, this work provides insights into the application of ExM for studying the interaction of primary human NK cells and A. fumigatus for the first time. Furthermore, this thesis presents first insights regarding the characterization of an A. fumigatus-targeting CAR, by applying super-resolution fluorescence microscopy, like SIM and dSTORM.}, subject = {Mikroskopie}, language = {en} } @phdthesis{Blahetek2024, author = {Blahetek, Gina}, title = {The role of alternative intronic polyadenylation on microRNA biogenesis in melanoma}, doi = {10.25972/OPUS-25474}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254743}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {mRNA is co- or post-transcriptionally processed from a precursor mRNA to a mature mRNA. In addition to 5'capping and splicing, these modifications also include polyadenylation, the addition of a polyA tail to the 3'end of the mRNA. In recent years, alternative polyadenylation in particular has increasingly been taken into account as a mechanism for regulating gene expression. It is assumed that approximately 70-75 \% of human protein coding genes contain alternative polyadenylation signals, which are often located within intronic sequences of protein-coding genes. The use of such polyadenylation signals leads to shortened mRNA transcripts and thus to the generation of C-terminal shortened protein isoforms. Interestingly, the majority of microRNAs, small non-coding RNAs that play an essential role in post-transcriptional gene regulation, are also encoded in intronic sequences of protein-coding genes and are co-transcriptionally expressed with their host genes. The biogenesis of microRNA has been well studied and is well known, but mechanisms that may influence the expression regulation of mature microRNAs are just poorly understood. In the presented work, I aimed to investigate the influence of alternative intronic polyadenylation on the biogenesis of microRNAs. The human ion channel TRPM1 could already be associated with melanoma pathogenesis and truncated isoforms of this protein have already been described in literature. In addition, TRPM1 harbors a microRNA, miR211, in its sixth intron, which is assumed to act as a tumor suppressor. Since both, TRPM1 and miR211 have already been associated with melanoma pathogenesis, the shift towards truncated transcripts during the development of various cancers is already known and it has been shown that certain microRNAs play a crucial role in the development and progression of melanoma, melanoma cell lines were used as an in vitro model for these investigations.}, subject = {Polyadenylierung}, language = {en} } @phdthesis{Nirchal2024, author = {Nirchal, Naveen Kumar}, title = {Mechanistische Regulierung des gastro{\"o}sophagealen {\"U}bergangs und die Rolle der Retins{\"a}ure bei der Entwicklung des Barrett-{\"O}sophagus}, doi = {10.25972/OPUS-31155}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311556}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Der gastro{\"o}sophageale {\"U}bergang (GEJ), der die Region abgrenzt, in der der distale {\"O}sophagus auf die proximale Magenregion trifft, ist bekannt f{\"u}r die Entwicklung pathologischer Zust{\"a}nde, wie Metaplasie und Adenokarzinom des {\"O}sophagus (EAC). Es ist wichtig, die Mechanismen der Entwicklungsstadien zu verstehen, die zu EAC f{\"u}hren, da die Inzidenzrate von EAC in den letzten 4 Jahrzehnten um das 7-fache gestiegen ist und die Gesamt{\"u}berlebensrate von 5 Jahren 18,4 \% betr{\"a}gt. In den meisten F{\"a}llenwird die Diagnose im fortgeschrittenen Stadium ohne vorherige Symptome erstellt. Der Hauptvorl{\"a}ufer f{\"u}r die Entwicklung von EAC ist eine pr{\"a}maligne Vorstufe namens Barrett-{\"O}sophagus (BE). BE ist der metaplastische Zustand, bei dem das mehrschichtige Plattenepithel des nativen {\"O}sophagus durch ein spezialisiertes einschichtiges S{\"a}ulenepithel ersetzt wird, das die molekularen Eigenschaften des Magen- sowie des Darmepithels aufweist. Zu den wichtigsten Risikofaktoren f{\"u}r die Entwicklung von BE geh{\"o}ren die chronische gastro{\"o}sophageale Refluxkrankheit (GERD), eine ver{\"a}nderte Mikrobiota und ver{\"a}nderte Retins{\"a}ure-Signalwege (RA). Es ist unklar, welche Zelle der Ursprung f{\"u}r BE ist, da es keine eindeutigen Beweisen f{\"u}r den Prozess der BE-Initiation gibt. In dieser Arbeit habe ich untersucht, wie die GEJ-Hom{\"o}ostase in gesundem Gewebe durch stammzellregulatorische Morphogene aufrechterhalten wird, welche Rolle der Vitamin-A (RA-Signal{\"u}bertragung) spieltund wie ihre Ver{\"a}nderung zur BE-Entwicklung beitr{\"a}gt. Im ersten Teil meiner Dissertation habe ich anhand von Einzelmolek{\"u}l-RNA in situ-Hybridisierung und Immunhistochemie eindeutig das Vorhandensein von zwei Arten von Epithelzellen nachweisen k{\"o}nnen, dem Plattenepithel in der Speiser{\"o}hre und dem S{\"a}ulenepithel imMagenbereich des GEJ. Mittels Abstammungsanalysen im Mausmodell konnte ich zeigen, dass die Epithelzellen des {\"O}sophagus und des Magens von zwei verschiedenen epithelialen Stammzelllinien imGEJ abstammen. Die Grenze zwischen Plattenepithel und S{\"a}ulenepithelzellen im SCJ des GEJ wirddurch gegens{\"a}tzliche Wnt-Mikroumgebungen streng reguliert. Plattenepithelstammzellen des {\"O}sophagus werden durch das Wnt-hemmende Mikroumgebungssignal aufrechterhalten, w{\"a}hrend Magens{\"a}ulenepithelzellen durch das Wnt-aktivierende Signal aus dem Stromakompartiment erhalten werden. Ich habe die in vivo Erhaltung der Epithelstammzellen des GEJ mit Hilfe eines in vitro Epithel-3D-Organoidkulturmodells rekonstruiert. Das Wachstum und die Vermehrung von Magens{\"a}ulenepithel-Organoiden h{\"a}ngen von Wnt-Wachstumsfaktoren ab, w{\"a}hrend das Wachstum von Plattenepithel-Organoiden von Wnt-defizienten Kulturbedingungen abh{\"a}ngt. Dar{\"u}ber hinaus zeigte die Einzelzell-RNA-Sequenzanalyse (scRNA-seq) der aus Organoiden gewonnenenEpithelzellen, dass der nicht-kanonische Wnt/ planar cell polarity (PCP) Signalweg an der Regulierung der Plattenepithelzellen beteiligt ist. Im Gegensatz dazu werden s{\"a}ulenf{\"o}rmige Magenepithelzellen durch den kanonischen Wnt/beta-Catenin- und den nicht-kanonischen Wnt/Ca2+-Weg reguliert. Meine Daten zeigen, dass die SCJ-Epithelzellen, die am GEJ verschmelzen, durch entgegengesetzte stromale Wnt-Faktoren und unterschiedliche Wnt-Weg-Signalee in den Epithelzellen reguliert werden. Im zweiten Teil der Dissertation untersuchte ich die Rolle der bioaktiven Vitamin A Verbindung RA auf {\"O}sophagus- und Magenepithelstammzellen. Die In-vitro-Behandlung von epithelialen Organoiden der Speiser{\"o}hre und des Magens mitRA oder seinem pharmakologischen Inhibitors BMS 493 zeigte, dass jeder Zelltyp unterschiedlich reguliert wurde. Ich beobachtete, dass eine verst{\"a}rkte RA die Differenzierung von Stammzellen und den Verlust der Schichtung f{\"o}rderte, w{\"a}hrend die RA-Hemmung zu einer verst{\"a}rkten Stammzellbildung und Regeneration im mehrschichtigen Epithel der Speiser{\"o}hre f{\"u}hrte. Im Gegensatz zur Speiser{\"o}hre ist der RA-Signalweg in Magen-Organoiden aktiv, und die Hemmung von RA hat ein reduziertes Wachstum von Magen-Organoiden. Globale transkriptomische Daten und scRNA-seq-Daten zeigten, dass derRA-Signalweg einen Ruheph{\"a}notyp in den {\"O}sophaguszellen induziert. Dagegen f{\"u}hrt das Fehlen von RA in Magenepithelzellen zur Expression von Genen, die mit BE assoziiert sind. Daher isteine r{\"a}umlich definierte Regulation der Wnt- und Retins{\"a}ure-Signalgebung amGEJ entscheidend f{\"u}r eine gesunde Hom{\"o}ostase, und ihre St{\"o}rung f{\"u}hrt zur Entwicklung von Krankheiten.}, subject = {Retinoes{\"a}ure}, language = {en} } @phdthesis{Scheiner2024, author = {Scheiner, Christin}, title = {Vulnerability in adolescence: prevalence, pandemic impact and prevention}, doi = {10.25972/OPUS-35164}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351644}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {This compilation focuses on adolescent mental disorders and their prevention. It comprises three distinct studies, each contributing to a deeper understanding of this critical topic. This work addresses a critical gap in the understanding of, and approach to, adolescent mental health, and as a result reveals a critically important and urgently needed policy implication for action. The thematic structure of these studies begins with an examination of the epidemiology of child and adolescent mental disorders. Baseline data were collected from N = 877 adolescents with a mean age of 12.43 years (SD = 0.65). Mental health problems, such as depressive symptoms, non-suicidal self-injury, suicidal ideation, symptoms of eating disorders, and gender differences, are thoroughly examined. Results revealed a significant portion of our sample displaying mental health problems as early as the 6th and 7th grades, with girls generally being more affected than boys. The findings underscore the importance of early adolescence in the emergence of mental health problems and thereby emphasize the need for preventive measures. Moving beyond prevalence estimates, the compilation delves into the etiology of these disorders, exploring their potential correlation with a COVID-19 infection. Understanding the early signs and risk factors is crucial for timely support. While numerous studies have investigated potential risk and protective factors during the pandemic, our focus shifts to adolescents' coping when an infection with the virus was involved (N = 2,154, M = 12.31, SD = 0.67). We hypothesized that students infected or with close family members infected, would exhibit an increased psychopathology and a decreased functioning of protective factors such as self-efficacy or self-esteem. We found no connection between infection and the mental health status within our sample, but protective factors and mental well-being were positively associated. Thus, universal primary prevention appears to be the preferred approach for promoting mental health. Lastly, the compilation introduces LessStress, a noteworthy contribution to more evidence-based prevention programs. This universal approach is designed to reduce stress in schools, accompanied by a cluster-randomized trial to evaluate its effectiveness (estimated sample size N = 1,894). Existing studies have demonstrated the effectiveness of stress prevention, leading us to introduce a short and easy-to-implement prevention program. There is positive evidence for one-lesson interventions in schools for promoting well-being and health behaviors among adolescents. LessStress is designed based on a life skills approach that not only imparts psychoeducational content but also teaches skills relevant to everyday life and directly applicable. Throughout these studies, a common thread emerges: the pressing need to address mental disorders during childhood and adolescence. These formative years play a pivotal role in the development of mental health problems. These formative years play a crucial role in the development of mental health problems. They highlight the importance of epidemiological data collection and analysis based on the latest models to develop prevention interventions that are not only effective but also reach young people on a global level.}, subject = {Jugend}, language = {en} } @phdthesis{WagenhaeusergebVonhausen2024, author = {Wagenh{\"a}user [geb. Vonhausen], Yvonne}, title = {Thermodynamic Investigations on the Dimerization and Anti-Cooperative Self-Assembly of Dipolar Merocyanines}, doi = {10.25972/OPUS-35211}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352111}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Dipolar merocyanines are very attractive supramolecular building blocks, as they combine interesting functional properties with strong, directional intermolecular interactions. The pyridine dioxocyano-pyridine (PYOP) chromophore (Chapter 2.2), used in this thesis, stands out because of its exceptionally high ground state dipole moment (g ~ 17 D), in combination with the option to retain good solubility also in unpolar solvents, by decoration with solubilizing groups. The reliable binding motif of anti-parallel -stacking due to dipole-dipole interactions has allowed the design of molecular building blocks that form assemblies of predictable geometry. The intense unstructured charge transfer UV/Vis absorption band (eg ~ 10.7 D) is a result of the dominant contribution of the zwitterionic resonance structure which brings the PYOP chromophore just beyond the cyanine limit in solvents of low polarity (c2 = 0.60, 1,4 dioxane). The high sensitivity of the S0 - S1 UV/Vis absorption band to the environment manifests itself in a pronounced negative solvatochromism and strong H-type exciton coupling within -stacked PYOP assemblies. In accordance with the classical molecular exciton theory, an increasing hypsochromic shift of the dominant absorption band of these H aggregates can be observed as the stack size increases up to about six chromophores, where it levels out at about max ~ 440 nm (CHCl3). This allows a uniquely simple estimation of the number of interacting chromophores within the self-assembled structure from a single UV/Vis absorption spectrum of an aggregate. The defined and well investigated PYOP dimer formation was employed in this thesis to probe the applicability and limitations of concentration-, temperature-, and solvent-dependent self-assembly studies (Chapter 3). Straightforward theoretical models to evaluate datasets of concentration-, temperature-, and solvent-dependent UV/Vis absorption by nonlinear regression analysis were derived for the case of dimer formation (Chapter 2.1). Although the dimer model is well known and widely applied in literature, this detailed derivation is helpful to understand assumptions and potential problems of the different approaches for the determination of thermodynamic parameters. This helps to decide on the most appropriate method to analyse a system of interest. In this regard it should be noted that covering a large portion of the self-assembly process with the experimental data is a prerequisite for the accuracy of the analysis. Additionally, many of the insights can also be transferred to other self-assembly systems like supramolecular polymerization or host-guest interactions. The concentration-dependent analysis is the most straightforward method to investigate self-assembly equilibria. No additional assumptions, besides mass balance and mass action law, are required. Since it includes the least number of parameters (only K, if M/D are known), it is the most, or even only, reliable method, to elucidate the self-assembly mechanism of an unknown system by model comparison. To cover a large concentration range, however, the compound must be soluble enough and generally sample amounts at least in the low mg scale must be available. The temperature-dependent analysis has the advantage that all thermodynamic parameters G0, H0 and S0 can be obtained from a single sample in one automated measurement. However, the accessible temperature-range is experimentally often quite limited and dependent on the solvent. For systems which do not show the transition from monomer to aggregate in a narrow temperature range, as given for, e.g., cooperative aggregation or processes with a high entropy contribution, often not the entire self-assembly process can be monitored. Furthermore, the assumptions of temperature-independent extinction coefficients of the individual species as well as temperature-independent H0 and S0 must be met. Monte Carlo simulations of data sets demonstrated that even minor changes in experimental data can significantly impact the optimized values for H0 and S0. This is due to the redundancy of these two parameters within the model framework and even small thermochromic effects can significantly influence the results. The G0 value, calculated from H0 and S0, is, however, still rather reliable. Solvent-dependent studies can often cover the entire self-assembly process from monomeric (agg = 0) to the fully aggregated state (agg = 1). However, for dyes with strong solvatochromic effects, such as the dipolar merocyanines investigated in this thesis, the results are affected. Also, the assumption of a linear relation of the binding energy G0 and the fraction of denaturating solvent f, which is based on linear free energy relationships between G0 and the solvent polarity, can lead to errors. Especially when specific solvent effects are involved. For the evaluation of experimental data by nonlinear regression, general data analysis software can be used, where user-defined fit models and known parameters can be implemented as desired. Alternatively, multiple specialized programs for analysing self-assembly data are available online. While the latter programs are usually more user-friendly, they have the disadvantage of being a "black box" where only pre-implemented models can be used without the option for the user to adapt models or parameters for a specific system. In Chapter 3 comprehensive UV/Vis absorption datasets are presented for the dimerization of merocyanine derivative 1 in 1,4-dioxane, which allowed for the first time a direct comparison of the results derived from concentration-, temperature-, and solvent-dependent self-assembly studies. The results for the binding constant K and corresponding G0 from the concentration- and temperature-dependent analysis were in very good agreement, also in comparison to the results from ITC. For the temperature-dependent analysis, though, multiple datasets of samples with different concentration had to be evaluated simultaneously to cover a meaningful part of the self-assembly process. Furthermore, a significant dependence of the optimized parameters H0 and S0 on the wavelength chosen for the analysis was observed. This can be rationalized by the small thermochromic shifts of both the monomer and the dimer UV/Vis absorption band. The results from the solvent-dependent evaluation showed the largest deviation, as expected for the highly solvatochromic merocyanine dye. However, even here by evaluation at 491 and 549 nm the deviation for G0 was only 2.5 kJ mol1 (9\%) with respect to the results from the concentration-dependent analysis (G0 = 29.1 kJ mol1). Thus, despite the strong solvatochromism of the dipolar chromophore, it can still be considered a reliable method for estimating the binding strength. Furthermore, multiple repetitions of the concentration-, temperature-, and solvent-dependent studies provided insight into the reproducibility of the results and possible sources of experimental errors. In all cases, the deviations of the results were small (G0 < 0.4 kJ mol1) and within the same range as the fit error from the nonlinear regression analysis. The insights from these studies were an important basis for the in-depth investigation of a more complex supramolecular system in Chapter 4, as a single method is often not enough to capture the full picture of a more complicated self-assembly process. To elucidate the anti-cooperative self-assembly of the chiral merocyanine 2, a combination of multiple techniques had to be applied. Solvent-dependent UV/Vis absorption studies in CH2Cl2/MCH mixtures showed the step-wise assembly of the merocyanine monomer (max(M) = 549 nm, CH2Cl2) to first a dimer (max(D) = 498 nm, CH2Cl2/MCH 15:85) by dipole-dipole interactions, and then a -stacked higher aggregate (max(H) = 477 nm, MCH), with pronounced H-type coupling. The thermodynamic evaluation of this data, however, suffered from the severe solvatochromism, especially of the monomeric species (max(M, CH2Cl2) = 549 nm, max(M, MCH) = 596 nm). Therefore, concentration-dependent studies were performed at three different temperatures (298, 323, 353 K) to elucidate the self-assembly mechanism and determine reliable thermodynamic parameters. The studies at elevated temperatures were hereby necessary, to obtain experimental data over a larger agg--range. Due to the pronounced difference in the thermodynamic driving force for dimerization and higher aggregate formation (KD/K5 = 6500) a concentration range exists in MCH where almost exclusively the dimer species of 2 is present, before further self-assembly by dispersion interactions occurs. Therefore, the data could be evaluated independently for the two self-assembly steps. The self-assembly of dimers into the higher aggregate could not be described by the isodesmic model but was fitted satisfactorily to a pentamer model. This rather small size of about ten -stacked PYOP chromophores was, furthermore, consistently indicated by AFM, VPO and DOSY NMR measurements. Based on 1D and 2D NMR data as well as the strong bisignate CD signal of the higher aggregate in combination with TD-DFT calculations, a P-helical stack is proposed as its structure. The small size can be rationalized by the anti-cooperative self-assembly mechanism and the sterical demand of the solubilizing trialkoxyphenyl and the chiral tetralin substituents. Additionally, the aliphatic shell formed by the solubilizing chains around the polar chromophore stack, can account for the exceptionally high solubility of 2 in MCH (> 15 mg mL1). These combined studies of the self-assembly process enabled the identification of suitable conditions for the investigation of fluorescence properties of the individual aggregate species. Aggregation-induced emission enhancement was observed for the almost non-emissive monomer (Fl(M) = 0.23\%), which can be rationalized by the increasing rigidification within the dimer (Fl(D) = 2.3\%) and the higher aggregate (Fl(H) = 4.5\%). The helical chirality of the PYOP decamer stack, furthermore, gave rise to a strong CPL signal with a large glum value of 0.011. The important conclusion of this thesis is that the temperature- and solvent-dependent analyses are valid alternatives to the classical concentration-dependent analysis to determine thermodynamic parameters of self-assembly equilibria. Although, for a specific supramolecular system, one approach might be favourable over the others for a variety of reasons. The experimental limitations often demand a combination of techniques to fully elucidate a self-assembly process and to gain insights in the aggregate structure. The anti-cooperative merocyanine self-assembly, which was described here for the first time for the PYOP merocyanine 2, is no exception. Besides the interest in the merocyanine assemblies from a structural and functional point of view, the insights gained from the presented studies can also be transferred to other self-assembly systems and be a guide to find the most appropriate analysis technique.}, subject = {Merocyanine}, language = {en} } @phdthesis{Bayer2024, author = {Bayer, Florian}, title = {Investigating electromagnetic properties of topological surface states in mercury telluride}, doi = {10.25972/OPUS-35212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-352127}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {This doctoral thesis investigates magneto-optical properties of mercury telluride layers grown tensile strained on cadmium telluride substrates. Here, layer thicknesses start above the usual quantum well thickness of about 20 nm and have a upper boundary around 100 nm due to lattice relaxation effects. This kind of layer system has been attributed to the material class of three-dimensional topological insulators in numerous publications. This class stands out due to intrinsic boundary states which cross the energetic band gap of the layer's bulk. In order to investigate the band structure properties in a narrow region around the Fermi edge, including possible boundary states, the method of highly precise time-domain Terahertz polarimetry is used. In the beginning, the state of the art of Teraherz technology at the start of this project is discussed, moving on to a detailed description and characterization of the self-built measurement setup. Typical standard deviation of a polarization rotation or ellipticity measurement are on the order of 10 to 100 millidegrees, according to the transmission strength through investigated samples. A range of polarization spectra, depending on external magnetic fields up to 10 Tesla, can be extracted from the time-domain signal via Fourier transformation. The identification of the actual band structure is done by modeling possible band structures by means of the envelope function approximation within the framework of the k·p method. First the bands are calculated based on well-established model parameters and from them the possible optical transitions and expected ellipticity spectra, all depending on external magnetic fields and the layer's charge carrier concentration. By comparing expected with measured spectra, the validity of k·p models with varying depths of detail is analyzed throughout this thesis. The rich information encoded in the ellipitcity spectra delivers key information for the attribution of single optical transitions, which are not part of pure absorption spectroscopy. For example, the sign of the ellipticity signals is linked to the mix of Landau levels which contribute to an optical transition, which shows direct evidence for bulk inversion asymmetry effects in the measured spectra. Throughout the thesis, the results are compared repeatedly with existing publications on the topic. It is shown that the models used there are often insufficient or, in worst case, plainly incorrect. Wherever meaningful and possible without greater detours, the differences to the conclusions that can be drawn from the k·p model are discussed. The analysis ends with a detailed look on remaining differences between model and measurement. It contains the quality of model parameters as well as different approaches to integrate electrostatic potentials that exist in the structures into the model. An outlook on possible future developments of the mercury cadmium telluride layer systems, as well as the application of the methods shown here onto further research questions concludes the thesis.}, subject = {Quecksilbertellurid}, language = {en} } @phdthesis{Koenig2024, author = {K{\"o}nig, Sebastian Thomas}, title = {Temperature-driven assembly processes of Orthoptera communities: Lessons on diversity, species traits, feeding interactions, and associated faecal microorganisms from elevational gradients in Southern Germany (Berchtesgaden Alps)}, doi = {10.25972/OPUS-35460}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-354608}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Chapter I: Introduction Temperature is a major driver of biodiversity and abundance patterns on our planet, which becomes particularly relevant facing the entanglement of an imminent biodiversity and climate crisis. Climate shapes the composition of species assemblages either directly via abiotic filtering mechanisms or indirectly through alterations in biotic interactions. Insects - integral elements of Earth's ecosystems - are affected by climatic variation such as warming, yet responses vary among species. While species' traits, antagonistic biotic interactions, and even species' microbial mutualists may determine temperature-dependent assembly processes, the lion's share of these complex relationships remains poorly understood due to methodological constraints. Mountains, recognized as hotspots of diversity and threatened by rapidly changing climatic conditions, can serve as natural experimental settings to study the response of insect assemblages and their trophic interactions to temperature variation, instrumentalizing the high regional heterogeneity of micro- and macroclimate. With this thesis, we aim to enhance our mechanistic understanding of temperature-driven assembly processes within insect communities, exemplified by Orthoptera, that are significant herbivores in temperate mountain grassland ecosystems. Therefore, we combined field surveys of Orthoptera assemblages on grassland sites with molecular tools for foodweb reconstruction, primarily leveraging the elevational gradients offered by the complex topography within the Berchtesgaden Alpine region (Bavaria, Germany) as surrogate for temperature variation (space-for-time substitution approach). In this framework, we studied the effects of temperature variation on (1) species richness, abundance, community composition, and interspecific as well as intraspecific trait patterns, (2) ecological feeding specialisation, and (3) previously neglected links to microbial associates found in the faeces. Chapter II: Temperature-driven assembly processes Climate varies at multiple scales. Since microclimate is often overlooked, we assessed effects of local temperature deviations on species and trait compositions of insect communities along macroclimatic temperature gradients in Chapter II. Therefore, we employed joint species distribution modelling to explore how traits drive variation in the climatic niches of Orthoptera species at grassland sites characterized by contrasting micro- and macroclimatic conditions. Our findings revealed two key insights: (1) additive effects of micro- and macroclimate on the diversity, but (2) interactive effects on the abundance of several species, resulting in turnover and indicating that species possess narrower climatic niches than their elevational distributions might imply. This chapter suggests positive effects of warming on Orthoptera, but also highlights that the interplay of macro- and microclimate plays a pivotal role in structuring insect communities. Thus, it underscores the importance of considering both elements when predicting the responses of species to climate change. Additionally, this chapter revealed inter- and intraspecific effects of traits on the niches and distribution of species. Chapter III: Dietary specialisation along climatic gradients A crucial trait linked to the position of climatic niches is dietary specialisation. According to the 'altitudinal niche-breadth hypothesis', species of high-elevation habitats should be less specialized compared to their low-elevation counterparts. However, empirical evidence on shifts in specialization is scarce for generalist insect herbivores and existing studies often fail to control for the phylogeny and abundance of interaction partners. In Chapter III, we used a combination of field observations and amplicon sequencing to reconstruct dietary relationships between Orthoptera and plants along an extensive temperature gradient. We did not find close but flexible links between individual grasshopper and plant taxa in space. While interaction network specialisation increased with temperature, the corrected dietary specialisation pattern peaked at intermediate elevations on assemblage level. These nuanced findings demonstrate that (1) resource availability, (2) phylogenetic relationships, and (3) climate can affect empirical foodwebs intra- and interspecifically and, hence, the dietary specialisation of herbivorous insects. In this context, we discuss that the underlying mechanisms involved in shaping the specialisation of herbivore assemblages may switch along temperature clines. Chapter IV: Links between faecal microbe communities, feeding habits, and climate Since gut microbes affect the fitness and digestion of insects, studying their diversity could provide novel insights into specialisation patterns. However, their association with insect hosts that differ in feeding habits and specialisation has never been investigated along elevational climatic gradients. In Chapter IV, we utilized the dietary information gathered in Chapter III to characterize links between insects with distinct feeding behaviour and the microbial communities present in their faeces, using amplicon sequencing. Both, feeding and climate affected the bacterial communities. However, the large overlap of microbes at site level suggests that common bacteria are acquired from the shared feeding environment, such as the plants consumed by the insects. These findings emphasize the influence of a broader environmental context on the composition of insect gut microbial communities. Chapter V: Discussion \& Conclusions Cumulatively, the sections of this dissertation provide support for the hypothesis that climatic conditions play a role in shaping plant-herbivore systems. The detected variation of taxonomic and functional compositions contributes to our understanding of assembly processes and resulting diversity patterns within Orthoptera communities, shedding light on the mechanisms that structure their trophic interactions in diverse climates. The combined results presented suggest that a warmer climate could foster an increase of Orthoptera species richness in Central European semi-natural grasslands, also because the weak links observed between insect herbivores and plants are unlikely to limit decoupled range shifts. However, the restructuring of Orthoptera communities in response to warmer temperatures depends on species' traits such as moisture preferences or phenology. Notably, we were able to demonstrate a crucial role of microclimate for many species, partly unravelling narrower climatic niches than their elevational ranges suggest. We found evidence that not only Orthoptera community composition, specialisation, and traits varied along elevational gradients, but even microbial communities in the faeces of Orthoptera changed, which is a novel finding. This complex restructuring and reassembly of communities, coupled with the nonlinear specialisation of trophic interactions and a high diversity of associated bacteria, emphasize our currently incomplete comprehension of how ecosystems will develop under future climatic conditions, demanding caution in making simplified predictions for biodiversity change under climate warming. Since these predictions may benefit from including biotic interactions and both, micro- and macroclimate based on our findings, conservation authorities and practitioners must not neglect improving microclimatic conditions to ensure local survival of a diverse set of threatened and demanding species. In this context, mountains can play a pivotal role for biodiversity conservation since these offer heterogeneous microclimatic conditions in proximity that can be utilized by species with distinct niches.}, subject = {Heuschrecken}, language = {en} } @phdthesis{Schneider2024, author = {Schneider, Florian Alexander}, title = {Voice Assistants are Social Actors - An Empirical Analysis of Media Equation Effects in Human-Voice Assistant Interaction}, doi = {10.25972/OPUS-34670}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346704}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Ownership and usage of personal voice assistant devices like Amazon Echo or Google Home have increased drastically over the last decade since their market launch. This thesis builds upon existing computers are social actors (CASA) and media equation research that is concerned with humans displaying social reactions usually exclusive to human-human interaction when interacting with media and technological devices. CASA research has been conducted with a variety of technological devices such as desktop computers, smartphones, embodied virtual agents, and robots. However, despite their increasing popularity, little empirical work has been done to examine social reactions towards these personal stand-alone voice assistant devices, also referred to as smart speakers. Thus, this dissertation aims to adopt the CASA approach to empirically evaluate social responses to smart speakers. With this goal in mind, four laboratory experiments with a total of 407 participants have been conducted for this thesis. Results show that participants display a wide range of social reactions when interacting with voice assistants. This includes the utilization of politeness strategies such as the interviewer-bias, which led to participants giving better evaluations directly to a smart speaker device compared to a separate computer. Participants also displayed prosocial behavior toward a smart speaker after interdependence and thus a team affiliation had been induced. In a third study, participants applied gender stereotypes to a smart speaker not only in self-reports but also exhibited conformal behavior patterns based on the voice the device used. In a fourth and final study, participants followed the rule of reciprocity and provided help to a smart speaker device that helped them in a prior interaction. This effect was also moderated by subjects' personalities, indicating that individual differences are relevant for CASA research. Consequently, this thesis provides strong empirical support for a voice assistants are social actors paradigm. This doctoral dissertation demonstrates the power and utility of this research paradigm for media psychological research and shows how considering voice assistant devices as social actors lead to a more profound understanding of voice-based technology. The findings discussed in this thesis also have implications for these devices that need to be carefully considered both in future research as well as in practical design.}, subject = {Mensch-Maschine-Kommunikation}, language = {en} } @article{TrifaultMamontovaCossaetal.2024, author = {Trifault, Barbara and Mamontova, Victoria and Cossa, Giacomo and Ganskih, Sabina and Wei, Yuanjie and Hofstetter, Julia and Bhandare, Pranjali and Baluapuri, Apoorva and Nieto, Blanca and Solvie, Daniel and Ade, Carsten P. and Gallant, Peter and Wolf, Elmar and Larsen, Dorthe H. and Munschauer, Mathias and Burger, Kaspar}, title = {Nucleolar detention of NONO shields DNA double-strand breaks from aberrant transcripts}, series = {Nucleic Acids Research}, volume = {52}, journal = {Nucleic Acids Research}, number = {6}, doi = {10.1093/nar/gkae022}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350208}, pages = {3050-3068}, year = {2024}, abstract = {RNA-binding proteins emerge as effectors of the DNA damage response (DDR). The multifunctional non-POU domain-containing octamer-binding protein NONO/p54\(^{nrb}\) marks nuclear paraspeckles in unperturbed cells, but also undergoes re-localization to the nucleolus upon induction of DNA double-strand breaks (DSBs). However, NONO nucleolar re-localization is poorly understood. Here we show that the topoisomerase II inhibitor etoposide stimulates the production of RNA polymerase II-dependent, DNA damage-inducible antisense intergenic non-coding RNA (asincRNA) in human cancer cells. Such transcripts originate from distinct nucleolar intergenic spacer regions and form DNA-RNA hybrids to tether NONO to the nucleolus in an RNA recognition motif 1 domain-dependent manner. NONO occupancy at protein-coding gene promoters is reduced by etoposide, which attenuates pre-mRNA synthesis, enhances NONO binding to pre-mRNA transcripts and is accompanied by nucleolar detention of a subset of such transcripts. The depletion or mutation of NONO interferes with detention and prolongs DSB signalling. Together, we describe a nucleolar DDR pathway that shields NONO and aberrant transcripts from DSBs to promote DNA repair.}, language = {en} } @article{HofstetterOgunleyeKutschkeetal.2024, author = {Hofstetter, Julia and Ogunleye, Ayoola and Kutschke, Andr{\´e} and Buchholz, Lisa Marie and Wolf, Elmar and Raabe, Thomas and Gallant, Peter}, title = {Spt5 interacts genetically with Myc and is limiting for brain tumor growth in Drosophila}, series = {Life Science Alliance}, volume = {7}, journal = {Life Science Alliance}, number = {1}, issn = {2575-1077}, doi = {10.26508/lsa.202302130}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350197}, year = {2024}, abstract = {The transcription factor SPT5 physically interacts with MYC oncoproteins and is essential for efficient transcriptional activation of MYC targets in cultured cells. Here, we use Drosophila to address the relevance of this interaction in a living organism. Spt5 displays moderate synergy with Myc in fast proliferating young imaginal disc cells. During later development, Spt5-knockdown has no detectable consequences on its own, but strongly enhances eye defects caused by Myc overexpression. Similarly, Spt5-knockdown in larval type 2 neuroblasts has only mild effects on brain development and survival of control flies, but dramatically shrinks the volumes of experimentally induced neuroblast tumors and significantly extends the lifespan of tumor-bearing animals. This beneficial effect is still observed when Spt5 is knocked down systemically and after tumor initiation, highlighting SPT5 as a potential drug target in human oncology.}, language = {en} } @phdthesis{Knorr2024, author = {Knorr, Susanne}, title = {Pathophysiology of early-onset isolated dystonia in a DYT-TOR1A rat model with trauma-induced dystonia-like movements}, doi = {10.25972/OPUS-20609}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206096}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Early-onset torsion dystonia (DYT-TOR1A, DYT1) is an inherited hyperkinetic movement disorder caused by a mutation of the TOR1A gene encoding the torsinA protein. DYT-TOR1A is characterized as a network disorder of the central nervous system (CNS), including predominantly the cortico-basal ganglia-thalamo-cortical loop resulting in a severe generalized dystonic phenotype. The pathophysiology of DYTTOR1A is not fully understood. Molecular levels up to large-scale network levels of the CNS are suggested to be affected in the pathophysiology of DYT-TOR1A. The reduced penetrance of 30\% - 40\% indicates a gene-environmental interaction, hypothesized as "second hit". The lack of appropriate and phenotypic DYT-TOR1A animal models encouraged us to verify the "second hit" hypothesis through a unilateral peripheral nerve trauma of the sciatic nerve in a transgenic asymptomatic DYT-TOR1A rat model (∆ETorA), overexpressing the human mutated torsinA protein. In a multiscale approach, this animal model was characterized phenotypically and pathophysiologically. Nerve-injured ∆ETorA rats revealed dystonia-like movements (DLM) with a partially generalized phenotype. A physiomarker of human dystonia, describing increased theta oscillation in the globus pallidus internus (GPi), was found in the entopeduncular nucleus (EP), the rodent equivalent to the human GPi, of nerve-injured ∆ETorA rats. Altered oscillation patterns were also observed in the primary motor cortex. Highfrequency stimulation (HFS) of the EP reduced DLM and modulated altered oscillatory activity in the EP and primary motor cortex in nerve-injured ∆ETorA rats. Moreover, the dopaminergic system in ∆ETorA rats demonstrated a significant increased striatal dopamine release and dopamine turnover. Whole transcriptome analysis revealed differentially expressed genes of the circadian clock and the energy metabolism, thereby pointing towards novel, putative pathways in the pathophysiology of DYTTOR1A dystonia. In summary, peripheral nerve trauma can trigger DLM in genetically predisposed asymptomatic ΔETorA rats leading to neurobiological alteration in the central motor network on multiple levels and thereby supporting the "second hit" hypothesis. This novel symptomatic DYT-TOR1A rat model, based on a DYT-TOR1A genetic background, may prove as a valuable chance for DYT-TOR1A dystonia, to further investigate the pathomechanism in more detail and to establish new treatment strategies.}, subject = {Dystonie}, language = {en} } @phdthesis{MaierverhHartmann2024, author = {Maier [verh. Hartmann], Carina Ramona}, title = {Regulation of the Mevalonate Pathway by the Deubiquitinase USP28 in Squamous Cancer}, doi = {10.25972/OPUS-34874}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348740}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The reprogramming of metabolic pathways is a hallmark of cancer: Tumour cells are dependent on the supply with metabolites and building blocks to fulfil their increased need as highly proliferating cells. Especially de novo synthesis pathways are upregulated when the cells of the growing tumours are not able to satisfy the required metabolic levels by uptake from the environment. De novo synthesis pathways are often under the control of master transcription factors which regulate the gene expression of enzymes involved in the synthesis process. The master regulators for de novo fatty acid synthesis and cholesterogenesis are sterol regulatory element-binding proteins (SREBPs). While SREBP1 preferably controls the expression of enzymes involved in fatty acid synthesis, SREBP2 regulates the transcription of the enzymes of the mevalonate pathway and downstream processes namely cholesterol, isoprenoids and building blocks for ubiquinone synthesis. SREBP activity is tightly regulated at different levels: The post-translational modification by ubiquitination decreases the stability of active SREBPs. The attachment of K48-linked ubiquitin chains marks the transcription factors for the proteasomal degradation. In tumour cells, high levels of active SREBPs are essential for the upregulation of the respective metabolic pathways. The increased stability and activity of SREBPs were investigated in this thesis. SREBPs are ubiquitinated by the E3 ligase Fbw7 which leads to the subsequential proteolysis of the transcription factors. The work conducted in this thesis identified the counteracting deubiquitination enzyme USP28 which removes the ubiquitin chains from SREBPs and prevents their proteasomal degradation. It further revealed that the stabilization of SREBP2 by USP28 plays an important role in the context of squamous cancers. Increased USP28 levels are associated with a poor survival in patients with squamous tumour subtypes. It was shown that reduced USP28 levels in cell lines and in vivo result in a decrease of SREBP2 activity and downregulation of the mevalonate pathway. This manipulation led to reduced proliferation and tumour growth. A direct comparison of adenocarcinomas and squamous cell carcinomas in lung cancer patients revealed an upregulation of USP28 as well as SREBP2 and its target genes. Targeting the USP28-SREBP2 regulatory axis in squamous cell lines by inhibitors also reduced cell viability and proliferation. In conclusion, this study reports evidence for the importance of the mevalonate pathway regulated by the USP28-SREBP2 axis in tumour initiation and progression of squamous cancer. The combinatorial inhibitor treatment of USP28 and HMGCR, the rate limiting enzyme of the mevalonate pathway, by statins opens the possibility for a targeted therapeutic treatment of squamous cancer patients.}, subject = {Ubiquitin}, language = {en} } @phdthesis{MeyerHeintze2024, author = {Meyer-Heintze, Simon}, title = {Holocene pedosedimentary sequences as archives for paleoenvironmental reconstructions}, doi = {10.25972/OPUS-34909}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349098}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Human-environment interaction has significantly altered the pedosphere since the Neolithic, if not since the early Holocene. In the course of clearance, agriculture, and (wood) pasture soils have been deeply modified or eroded. These types of land use practices but above all forms of sedentariness spread alongside floodplains and trajectories were oriented towards loess covered areas where fertile soils could develop. Besides this, also peripheral / marginal regions were settled due to population pressure or other factors. Evidence for landscape history and development can be found within archeological sites but also overbank deposits and anthropogenic slope deposits document vast transformation processes. The presented investigations took place within the natural region of the Windsheimer Bucht which is locat-ed in the district of Middle Franconia in northern Bavaria, Germany. In this area, Holocene soils predomi-nantly developed within mudstones of the Middle to Upper Triassic. The soil texture is extremely clay-rich which renders the soils problematic with regard to cultivation management. As a peculiarity, the gypsum underlying the mudstones is prone to karstification processes and resulting proceeding geomorphological processes shape the surface of the landscape. In the course of gypsum mining the karst forms are being exposed and archeological findings are being documented. The latter mainly date back to a span from the Neolithic to the Iron Age, but partly are of Younger Paleolithic origin. Especially subsidence sinkholes are capable of storing pedosediments of several meters in thickness. Despite the high clay content and connect-ed pedoturbation processes, the excavated sequences are stratigraphically and pedologically well-differentiated. The archives occur in the context of settlement structures such as pits and postholes; there-fore, they developed at the interface of natural developments and human impact on their surroundings. The main original research questions that were formulated within the general frame of a project funded by the Deutsche Forschungsgemeinschaft (DFG-projects Te295/15-1 and -2 and Fa390/9-1 and -2) focused on the attractors of the peripheral region for early settlers, the pedological conditions before land use, but also the impact of humans on soils and karst dynamics through time. In the course of the in hand study, the pedosedimentary archives have been approached with a multimethodological toolset which consisted of field analyses, soil morphological analyses from micro- to macro-scale, spectrophotometric (color), (laser) granulometric, and (iron-) pedochemical analyses. The numerical chronological frame was spanned by radiocarbon dating of different organic remains and bulk material if soil organic carbon was supposed-ly high. The result is a multi-dimensional data set that consists of analyses on different spatial scales but also on different levels of measurement. Thus, qualitative, semi-quantitative, and quantitative data consti-tute the basis for discussion. While the grain-size analyses underline the general sedimentological differen-tiation of the records and further affirm the high clay content within the pedosedimentary layers, iron-pedochemical analyses indicate an interplay between oxidation of iron and its chemical reduction. This is also manifested within the spectrophotometric record. Especially the versatile pedogenic characteristics that have been identified by field analyses are confirmed within the thin sections and, by considering all different analyses, the polygenic character of the pedosediments is emphasized. After stressing the general pedological specificities among the different investigated sites within the re-search area, for the collected data, the research further branches into the subjects of general notions on pedogenesis in clayey material and the classification of the respective pedosediments according to paleo-pedological concepts but also recent schemes. Concerning the latter, it becomes evident that established principles cannot be applied to the studied pedosediments without major adaptions. This underlines the specific characteristics of the material. The basis for further interpretations is the evaluation of the multi-level data set for the single records with regard to profile development and pedogenic processes. Hereby, the main drivers of pedogenesis could be identified, which are karst dynamics, land use, and subtle changes in parent material due to the admixture of slope deposits that contain allochthonous eolian material. The latter underlines the importance of Pleis-tocene preconditioning for understanding Holocene landscape dynamics. At the same time, a differentia-tion between the mentioned factors and Holocene climate development is difficult. The following compila-tion of record and localities within the given time frame unveils synchronous as well as asynchronous de-velopments; however, a clear connection between phases of Holocene climate and pedogenesis within the pedosediments cannot be established. Instead, it becomes evident that site specific factors or those that act on the scale of the micro-catchment of the investigated records are decisive. The aforementioned main topics of the project are also considered in the in hand study from a soil-geographic perspective: it is possible that before land use, there was an insular or thin cover by loess sedi-ments or at least upper layers (according to the concept of periglacial cover beds) which constituted the parent material for Holocene soil formation. The according soils, which were superior for agricultural purposes compared to those developed on the autochthonous mudstones, were eroded which exposed the clayey Upper to Middle Triassic beds. Erosion was aggravated due to the impermeable mudstones which enhanced overland flow and interflow within the overlying silty (loessic) material. This is further support-ed by the notions on erodibility of the clayey material that are derived from the comparison of conven-tional and laser granulometric analyses: probably, the clayey pedosediments are capable of forming micro-aggregates that can easily be eroded during heavy rainfall events despite the general consent that material with heavy texture should be rather resistant. The study presents a comprehensive view on clay-rich pedosediments and the complex effects of human-environment interaction on pedogenic as well as sedimentary processes through time that have not been investigated in such detail before. In this context, the multi-level soil morphological analyses and their necessity for a genetic interpretation with regard to the influence of natural versus anthropogenic factors need to be emphasized. Based on quantitative laboratory analytical data only, a respective differentiation would not be possible. This underlines the importance of the chosen soil-geographic multi-methodological approach for answering questions with regard to human-environment interaction but also geoarcheology in general.}, subject = {Geoarch{\"a}ologie}, language = {en} } @phdthesis{Huang2023, author = {Huang, Shouguang}, title = {Role of ABA-induced Ca\(^{2+}\) signals, and the Ca\(^{2+}\)-controlled protein kinase CIPK23, in regulation of stomatal movements}, doi = {10.25972/OPUS-20473}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204737}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Stomata are pores in the leaf surface, formed by pairs of guard cells. The guard cells modulate the aperture of stomata, to balance uptake of CO2 and loss of water vapor to the atmosphere. During drought, the phytohormone abscisic acid (ABA) provokes stomatal closure, via a signaling chain with both Ca2+-dependent and Ca2+-independent branches. Both branches are likely to activate SLAC1-type (Slow Anion Channel Associated 1) anion channels that are essential for initiating the closure of stomata. However, the importance of the Ca2+-dependent signaling branch is still debated, as the core ABA signaling pathway only possesses Ca2+-independent components. Therefore, the aim of this thesis was to address the role of the Ca2+-dependent branch in the ABA signaling pathway of guard cells. In the first part of the thesis, the relation between ABA-induced Ca2+ signals and stomatal closure was studied, with guard cells that express the genetically encoded Ca2+-indicator R-GECO1-mTurquoise. Ejection of ABA into the guard cell wall rapidly induced stomatal closure, however, only in ¾ of the guard cells ABA evoked a cytosolic Ca2+ signal. A small subset of stomata (¼ of the experiments) closed without Ca2+ signals, showing that the Ca2+ signals are not essential for ABA-induced stomatal closure. However, stomata in which ABA evoked Ca2+ signals closed faster as those in which no Ca2+ signals were detected. Apparently, ABA-induced Ca2+ signals enhance the velocity of stomatal closure. In addition to ABA, hyperpolarizing voltage pulses could also trigger Ca2+ signals in wild type guard cells, which in turn activated S-type anion channels. However, these voltage pulses failed to elicit S-type anion currents in the slac1/slah3 guard cells, suggesting that SLAC1 and SLAH3 contribute to Ca2+-activated conductance. Taken together, our data indicate that ABA-induced Ca2+ signals enhance the activity of S-type anion channels, which accelerates stomatal closure. The second part of the thesis deals with the signaling pathway downstream of the Ca2+ signals. Two types of Ca2+-dependent protein kinase modules (CPKs and CBL/CIPKs) have been implicated in guard cells. We focused on the protein kinase CIPK23 (CBL-Interacting Protein Kinase 23), which is activated by the Ca2+-dependent protein CBL1 or 9 (Calcineurin B-Like protein 1 or 9) via interacting with the NAF domain of CIPK23. The CBL1/9-CIPK23 complex has been shown to affect stomatal movements, but the underlying molecular mechanisms remain largely unknown. We addressed this topic by using an estrogen-induced expression system, which specifically enhances the expression of wild type CIPK23, a phosphomimic CIPK23T190D and a kinase dead CIPK23K60N in guard cells. Our data show that guard cells expressing CIPK23T190D promoted stomatal opening, while CIPK23K60N enhanced ABA-induced stomatal closure, suggesting that CIPK23 is a negative regulator of stomatal closure. Electrophysiological measurements revealed that the inward K+ channel currents were similar in guard cells that expressed CIPK23, CIPK23T190D or CIPK23K60N, indicating that CIPK23-mediated inward K+ channel AKT1 does not contribute to stomatal movements. Expression of CIPK23K60N, or loss of CIPK23 in guard cells enhanced S-type anion activity, while the active CIPK23T190D inhibited the activity of these anion channels. These results are in line with the detected changes in stomatal movements and thus indicate that CIPK23 regulates stomatal movements by inhibiting S-type anion channels. CIPK23 thus serves as a brake to control anion channel activity. Overall, our findings demonstrate that CIPK23-mediated stomatal movements do not depend on CIPK23-AKT1 module, instead, it is achieved by regulating S-type anion channels SLAC1 and SLAH3. In sum, the data presented in this thesis give new insights into the Ca2+-dependent branch of ABA signaling, which may help to put forward new strategies to breed plants with enhanced drought stress tolerance, and in turn boost agricultural productivity in the future.}, language = {en} } @phdthesis{Mahl2023, author = {Mahl, Magnus}, title = {Polycyclic Aromatic Dicarboximides as NIR Chromophores, Solid-State Emitters and Supramolecular Host Platforms}, doi = {10.25972/OPUS-23462}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234623}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The present thesis introduce different synthetic strategies towards a variety of polycyclic aromatic dicarboximides (PADIs) with highly interesting and diverse properties. This included tetrachlorinated, tetraaryloxy- and tetraaryl-substituted dicarboximides, fused acceptor‒donor(‒acceptor) structures as well as sterically shielded rylene and nanographene dicarboximides. The properties and thus the disclosure of structure‒property relationships of the resulting dyes were investigated in detail among others with UV‒vis absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and single crystal X-ray analysis. For instance, some of the fused and substituted PADIs offer strong absorption of visible and near infrared (NIR) light, NIR emission and low-lying LUMO levels. On the contrary, intriguing optical features in the solid-state characterize the rylene dicarboximides with their bulky N-substituents, while the devised sterically enwrapped nanographene host offered remarkable complexation capabilities in solution.}, subject = {Organische Chemie}, language = {en} } @phdthesis{Yuan2023, author = {Yuan, Xidi}, title = {Aging and inflammation in the peripheral nervous system}, doi = {10.25972/OPUS-23737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237378}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Aging is known to be a risk factor for structural abnormalities and functional decline in the nervous system. Characterizing age-related changes is important to identify putative pathways to overcome deleterious effects and improve life quality for the elderly. In this study, the peripheral nervous system of 24-month-old aged C57BL/6 mice has been investigated and compared to 12-month-old adult mice. Aged mice showed pathological alterations in their peripheral nerves similar to nerve biopsies from elderly human individuals, with nerve fibers showing demyelination and axonal damage. Such changes were lacking in nerves of adult 12-month-old mice and adult, non-aged humans. Moreover, neuromuscular junctions of 24-month-old mice showed increased denervation compared to adult mice. These alterations were accompanied by elevated numbers of macrophages in the peripheral nerves of aged mice. The neuroinflammatory conditions were associated with impaired myelin integrity and with a decline of nerve conduction properties and muscle strength in aged mice. To determine the pathological impact of macrophages in the aging mice, macrophage depletion was performed in mice by oral administration of CSF-1R specific kinase (c-FMS) inhibitor PLX5622 (300 mg/kg body weight), which reduced the number of macrophages in the peripheral nerves by 70\%. The treated mice showed attenuated demyelination, less muscle denervation and preserved muscle strength. This indicates that macrophage-driven inflammation in the peripheral nerves is partially responsible for the age-related neuropathy in mice. Based on previous observations that systemic inflammation can accelerate disease progression in mouse models of neurodegenerative diseases, it was hypothesized that systemic inflammation can exacerbate the peripheral neuropathy found in aged mice. To investigate this hypothesis, aged C57BL/6 mice were intraperitoneally injected with a single dose of lipopolysaccharide (LPS; 500 μg/kg body weight) to induce systemic inflammation by mimicking bacterial infection, mostly via activation of Toll-like receptors (TLRs). Altered endoneurial macrophage activation, highlighted by Trem2 downregulation, was found in LPS injected aged mice one month after injection. This was accompanied by a so far rarely observed form of axonal perturbation, i.e., the occurrence of "dark axons" characterized by a damaged cytoskeleton and an increased overall electron density of the axoplasm. At the same time, however, LPS injection reduced demyelination and muscle denervation in aged mice. Interestingly, TREM2 deficiency in aged mice led to similar changes to LPS injection. This suggests that LPS injection likely mitigates aging-related demyelination and muscle denervation via Trem2 downregulation. Taken together, this study reveals the role of macrophage-driven inflammation as a pathogenic mediator in age-related peripheral neuropathy, and that targeting macrophages might be an option to mitigate peripheral neuropathies in aging individuals. Furthermore, this study shows that systemic inflammation may be an ambivalent modifier of age-related nerve damage, leading to a distinct type of axonal perturbation, but in addition to functionally counteracting, dampened demyelination and muscle denervation. Translationally, it is plausible to assume that tipping the balance of macrophage polarization to one direction or the other may determine the functional outcome in the aging peripheral nervous system of the elderly.}, subject = {Maus}, language = {en} } @phdthesis{Schwarzmeier2023, author = {Schwarzmeier, Hanna}, title = {From fear extinction to exposure therapy: neural mechanisms and moderators of extinction}, doi = {10.25972/OPUS-22330}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223304}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Emotional-associative learning processes such as fear conditioning and extinction are highly relevant to not only the development and maintenance of anxiety disorders (ADs), but also to their treatment. Extinction, as the laboratory analogue to behavioral exposure, is assumed a core process underlying the treatment of ADs. Although exposure-based treatments are highly effective for the average patient suffering from an AD, there remains a gap in treatment efficacy with over one third of patients failing to achieve clinically significant symptom relief. There is ergo a pressing need for intensified research regarding the underlying neural mechanisms of aberrant emotional-associative learning processes and the neurobiological moderators of treatment (non-)response in ADs. The current thesis focuses on different applications of the fundamental principles of fear conditioning and extinction by using two example cases of ADs from two different multicenter trials. First, we targeted alterations in fear acquisition, extinction, and its recall as a function of psychopathology in panic disorder (PD) patients compared to healthy subjects using fMRI. Second, exposure-based therapy and pre-treatment patient characteristics exerting a moderating influence on this essential learning process later on (i.e. treatment outcome) were examined using multimodal functional and structural neuroimaging in spider phobia. We observed aberrations in emotional-associative learning processes in PD patients compared to healthy subjects indicated by an accelerated fear acquisition and an attenuated extinction recall. Furthermore, pre-treatment differences related to defensive, regulatory, attentional, and perceptual processes may exert a moderating influence on treatment outcome to behavioral exposure in spider phobia. Although the current results need further replication, on an integrative meta level, results point to a hyperactive defensive network system and deficient emotion regulation processes (including extinction processes) and top-down control in ADs. This speaks in favor of transdiagnostic deficits in important functional domains in ADs. Deficits in transdiagnostic domains such as emotion regulation processes could be targeted by enhancing extinction learning or by means of promising tools like neurofeedback. The detection of pre-treatment clinical response moderators, for instance via machine learning frameworks, may help in supporting clinical decision making on individually tailored treatment approaches or, respectively, to avoid ineffective treatment and its related financial costs. In the long run, the identification of neurobiological markers which are capable of detecting non-responders a priori represents an ultimate goal.}, subject = {Extinktion}, language = {en} } @phdthesis{Yin2023, author = {Yin, Jing}, title = {Progressive alterations of pro- and antidegeneration markers in the nigrostriatal tract of the AAV1/2-A53T-α synuclein rat model of Parkinson's disease}, doi = {10.25972/OPUS-26064}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260645}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Neurodegeneration plays an essential role in Parkinson's disease (PD). Several crucial neuronal pro-and antidegeneration markers were described to be altered in disease models accompanied by neurodegeneration. In the AAV1/2-A53T-aSyn PD rat model progressive time-dependent motor impairment and neurodegeneration in the nigrostriatal tract starting from 2 weeks after PD model induction could be found. Downregulation of Nrf2 in SN and nigrostriatal axon localization, a trend of Tau downregulation in SN and upregulation in axon localization in the AAV1/2-A53T-aSyn PD rat model were observed, indicating potential therapeutic value of these two molecular targets in PD. No alterations of SARM1 and NMNAT2 could be detected, indicating little relevance of these two molecules with our AAV1/2-A53T-aSyn rat model.}, language = {en} } @phdthesis{Kade2023, author = {Kade, Juliane Carolin}, title = {Expanding the Processability of Polymers for a High-Resolution 3D Printing Technology}, doi = {10.25972/OPUS-27005}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270057}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {This thesis identifies how the printing conditions for a high-resolution additive manufacturing technique, melt electrowriting (MEW), needs to be adjusted to process electroactive polymers (EAPs) into microfibers. Using EAPs based on poly(vinylidene difluoride) (PVDF), their ability to be MEW-processed is studied and expands the list of processable materials for this technology.}, subject = {Polymere}, language = {en} } @phdthesis{JanzenMaaser2023, author = {Janzen-Maaser, Anita}, title = {Prevalence of Strongyloides infection and other intestinal parasites in paediatric patients in a referral hospital in Northern Tanzania}, doi = {10.25972/OPUS-29702}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297023}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The StrongPaed study in the paediatric ward of a referral hospital in Mwanza in the lake region of Tanzania showed the prevalence of S. stercoralis, G. lamblia, E. histolytica and E. dispar as well as of other intestinal parasites with various diagnostic methods. The prevalence of S. stercoralis was 2-10 \% depending on the diagnostic methods used. There were no symptomatic infections but only carriage of the nematode. The positive results differed greatly depending on the performed diagnostic methods. None of the diagnostics showed satisfying results, neither in sensitivity and specificity nor in feasibility for this population in an endemic region in sub-Saharan Africa. PCR and microscopy were limited by the low amount of examined stool samples and by the resulting lack of sensitivity. Stool cultures were limited by time-consuming procedures and mainly by the problem of differentiation from hookworm and the resulting lack of specificity. ELISA was limited by the need of blood samples and also by poor specificity in the ELISA used. The prevalence of G. lamblia was high, but mostly only carriage and not symptomatic infections was seen. No E. histolytica was detected, but 8.5 \% samples were positive for E. dispar. Among the performed diagnostics, the rapid test showed sufficient results. It showed better sensitivity than microscopy and is cheaper and more feasible than PCR. Differentiation between E. histolytica and E. dispar was only possible with qPCR performed in Germany. More children were positive for intestinal parasites from rural than from urban areas. The profession of the parents working as farmers was a risk factor for intestinal parasitic infections. Hygienic living conditions such as access to tap water and flush toilets at home were preventive for intestinal parasitic infections in children.}, subject = {Strongyloides}, language = {en} } @phdthesis{Noll2023, author = {Noll, Niklas}, title = {Second Coordination Sphere Engineering in Macrocyclic Ruthenium Water Oxidation Catalysts}, doi = {10.25972/OPUS-30533}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305332}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {About 2.4 billion years ago, nature has fundamentally revolutionized life on earth by inventing the multi-subunit protein complex photosystem II, the only molecular machine in nature that catalyzes the thermodynamically demanding photosynthetic splitting of water into oxygen and reducing equivalents. Nature chose a distorted Mn4CaO5 cluster as catalyst, better known as oxygen-evolving complex (OEC), thus recognizing the need for transition metals to achieve high-performance catalysts. The curiosity has always driven mankind to mimic nature's achievements, but the performance of natural enzymes such as the oxygen-evolving complex in photosystem II remain commonly unmatched. An important role in fine-tuning and regulating the activity of natural enzymes is attributed to the surrounding protein domain, which facilitates substrate preorganization within well-defined nanoenvironments. In light of growing energy demands and the depletion of fossil fuels, the unparalleled efficiency of natural photosynthesis inspires chemists to artificially mimic its natural counterpart to generate hydrogen as a 'solar fuel' through the light-driven splitting of water. As a result, significant efforts have been devoted in recent decades to develop molecular water oxidation catalysts based on earth-abundant transition metals and the discovery of the Ru(bda) (bda: 2,2' bipyridine-6,6'-dicarboxylate) catalyst family enabled activities comparable to the natural OEC. Similar to the natural archetypes, the design of homogeneous catalysts that interplay judiciously with the second coordination sphere of the outer ligand framework proved to be a promising concept for catalyst design. In this present thesis, novel supramolecular design approaches for enzyme like activation of substrate water molecules for the challenging oxidative water splitting reaction were established via tailor-made engineering of the secondary ligand environment of macrocyclic Ru(bda) catalysts.}, subject = {Katalyse}, language = {en} } @misc{Seefried2023, author = {Seefried, Lothar}, title = {Supplement: Impaired Physical Performance in X-linked Hypophosphatemia is not caused by depleted muscular phosphate stores}, series = {Journal of Clinical Endocrinology \& Metabolism}, journal = {Journal of Clinical Endocrinology \& Metabolism}, doi = {10.25972/OPUS-30364}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303647}, year = {2023}, abstract = {Supplemental Data to "Impaired Physical Performance in X-linked Hypophosphatemia is not caused by depleted muscular phosphate stores"}, language = {en} } @phdthesis{Leistner2023, author = {Leistner, Adrian Dieter}, title = {Improving the quality analysis of monographed drugs - dapsone, baclofen, acarbose and other selected APIs}, doi = {10.25972/OPUS-30331}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303318}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {All presented studies aimed on the improvement of the quality analysis of already monographed drugs. Thereby different LC methods were applied and coupled to i.e., the UV/VIS detector, the CAD or a hyphenation of these detectors, respectively. The choice of the chromatographic system including the detector was largely dependent on the physicochemical properties of the respective analytes. With the risk-assessment report on the API cetirizine we presented an exemplary tool, that can help to minimize the risk of the occurrence of unexpected impurities. An in- deep analysis of each step within synthesis pathway by means of reaction matrices of all compounds was performed. It is essential to understand the complete impurity profile of all reactants, solvents, and catalysts and to include them in the matrix. Finally, the API of this synthesis was checked if all impurities are identified by this tool. Of note, a shortcoming of such a targeted approach is that impurities can still occur, but they are not captured. This disadvantage can be partially compensated by non-targeted approaches if they are performed in parallel with the other studies that represent most of the impurities. However, this work also shows that even in a supposedly simple synthesis, potentially hundreds of by-products can be formed. For each of them, it must be decided individually whether their formation is probable or how their quantity can be minimized in order to obtain APIs, that are as pure as possible. In the dapsone project it was aimed to replace the existing old Ph. Eur. TLC method with a modern RP-HPLC method. This was successful and since Ph. Eur. 10.6, the method developed in this work, became a valid monograph. Within the revision process of the monograph, the individual limits for impurities were tightened. However, this new method needs HPLC instrumentation, suitable to perform gradients. As this is not always available in all control laboratories, we also developed an alternative, more simple method using two different isocratic runs for the impurity analysis. The obtained batch results of both, the new pharmacopoeial method and the more simple one, were in a comparable order of magnitude. Furthermore, within the method development stage of the Ph. Eur. method, we could identify one unknown impurity of the impurity reference by high-resolution MS/MS analysis. Also, in the baclofen project it was aimed to replace the existing Ph. Eur. method with the introduction of an additional impurity to be quantified. A corresponding method was developed and validated. However, due to the harmonization process of the pharmacopoeias, it is currently not used. In addition, we tried to find further, non- 116 SUMMARY chromophoric impurities by means of the CAD. However, except for one counterion of an impurity, no further impurities were found. Also, the aforementioned new impurity could not be detected above the reporting threshold in the batches analyzed. As the only individually specified impurity A is also present at a low level, it can be concluded that the examined batches of baclofen are very pure. The use of universal detectors, such as the CAD can be particularly interesting for compounds with no chromophore or those with only a weak chromophore. Therefore, we decided to take a closer look at the impurity profile of acarbose. Currently, acarbose and its impurities are being studied by low wavelength UV detection at 210 nm. Therefore, the question arose whether there are no other impurities in the API that do not show absorption at this wavelength. CAD, which offers consistent detection properties for all non-volatile compounds, is ideally suited for this purpose. However, it was not so easy to use the CAD together with the UV detector, for example, as a hyphenated detection technique, because the Ph. Eur. method uses phosphate buffers. However, this is non-volatile and therefore inappropriate for the CAD. Therefore, an attempt was made to replace the buffer with a volatile one. However, since this did not lead to satisfactory results and rather the self-degradation process of the stationary phase used could be observed by means of the CAD, it was decided to switch to alternative stationary phases. A column screening also revealed further difficulties with acarbose and its impurities: they show an epimerization reaction at the end of the sugar chain. However, since one wanted to have uniform peaks in the corresponding chromatograms, one had to accelerate this reaction significantly to obtain only one peak for each component. This was best achieved by using two stationary phases: PGC and Amide-HILIC. Impurity-profiling methods could be developed on each of the two phases. In addition, as expected, new impurities could be detected, albeit at a low level. Two of them could even be identified by spiking experiments as the sugar fragments maltose and maltotriose. Taken together, it can be concluded, that this work has contributed significantly to the improvement of the quality analysis of monographed drugs. In addition to the presented general tool for the identification of potential impurities, one of the methods developed, had already been implemented to the Ph. Eur. In an effort to improve the CAD's universal detection capabilities, additional methods have also been developed. Further, new improved methods for the impurity profiling are ready to use.}, subject = {Instrumentelle Analytik}, language = {en} } @phdthesis{Cherpokova2023, author = {Cherpokova, Deya}, title = {Studies on modulators of platelet (hem)ITAM signaling and platelet production in genetically modified mice}, doi = {10.25972/OPUS-30377}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303777}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Summary Platelet activation and aggregation at sites of vascular injury is critical to prevent excessive blood loss, but may also lead to life-threatening ischemic disease states, such as myocardial infarction and stroke. Glycoprotein (GP) VI and C type lectin-like receptor 2 (CLEC-2) are essential platelet activating receptors in hemostasis and thrombo-inflammatory disease which signal through a (hem)immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway. The adapter molecules Src-like adapter protein (SLAP) and SLAP2 are involved in the regulation of immune cell receptor surface expression and signaling, but their function in platelets is unknown. As revealed in this thesis, single deficiency of SLAP or SLAP2 in mice had only moderate effects on platelet function, while SLAP/SLAP2 double deficiency resulted in markedly increased signal transduction, integrin activation, granule release, aggregation, procoagulant activity and thrombin generation following (hem)ITAM-coupled, but not G protein-coupled receptor activation. Slap-/-/Slap2-/- mice displayed accelerated occlusive arterial thrombus formation and a dramatically worsened outcome after focal cerebral ischemia. These results establish SLAP and SLAP2 as critical inhibitors of platelet (hem)ITAM signaling in the setting of arterial thrombosis and ischemic stroke. GPVI has emerged as a promising novel pharmacological target for treatment of thrombotic and inflammatory disease states, but the exact mechanisms of its immunodepletion in vivo are incompletely understood. It was hypothesized that SLAP and SLAP2 may be involved in the control of GPVI down-regulation because of their role in the internalization of immune cell receptors. As demonstrated in the second part of the thesis, SLAP and SLAP2 were dispensable for antibody-induced GPVI down-regulation, but anti-GPVI treatment resulted in prolonged strong thrombocytopenia in Slap-/-/Slap2-/- mice. The profound thrombocytopenia likely resulted from the powerful platelet activation which the anti-GPVI antibody induced in Slap-/-/Slap2-/- platelets, but importantly, not in wild-type platelets. These data indicate that the expression and activation state of key modulators of the GPVI signaling cascade may have important implications for the safety profile and efficacy of anti-GPVI agents. Small GTPases of the Rho family, such as RhoA and Cdc42, are critically involved in the regulation of cytoskeletal rearrangements during platelet activation, but little is known about the specific roles and functional redundancy of both proteins in platelet biogenesis. As shown in the final part of the thesis, combined deficiency of RhoA and Cdc42 led to marked alterations in megakaryocyte morphology and the generation of platelets of heterogeneous size and granule content. Despite severe hemostatic defects and profound thrombo¬cytopenia, circulating RhoA-/-/Cdc42-/- platelets were still capable of granule secretion and the formation of occlusive thrombi. These results implicate the existence of both distinct and overlapping roles of RhoA and Cdc42 in platelet production and function.}, subject = {Thrombozyt}, language = {en} } @phdthesis{Hapke2023, author = {Hapke, Nils}, title = {Cardiac antigen derived T cell epitopes in the frame of myocardial infarction}, doi = {10.25972/OPUS-30196}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301963}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Cardiovascular disease and the acute consequence of myocardial infarc- tion remain one of the most important causes of morbidity and mortality in all western societies. While much progress has been made in mitigating the acute, life-threatening ischemia caused by infarction, heart failure of the damaged my- ocardium remains prevalent. There is mounting evidence for the role of T cells in the healing process after myocardial infarction, but relevant autoantigens, which might trigger and regulate adaptive immune involvement have not been discov- ered in patients. In this work, we discovered an autoantigenic epitope in the adrenergic receptor beta 1, which is highly expressed in the heart. This autoantigenic epitope causes a pro-inflammatory immune reaction in T cells isolated from pa- tients after myocardial infarction (MI) but not in control patients. This immune reaction was only observed in a subset of MI patients, which carry at least one allele of the HLA-DRB1*13 family. Interestingly, HLA-DRB1*13 was more com- monly expressed in patients in the MI group than in the control group. Taken together, our data suggests antigen-specific priming of T cells in MI patients, which leads to a pro-inflammatory phenotype. The primed T cells react to a cardiac derived autoantigen ex vivo and are likely to exhibit a similar phenotype in vivo. This immune phenotype was only observed in a certain sub- set of patients sharing a common HLA-allele, which was more commonly ex- pressed in MI patients, suggesting a possible role as a risk factor for cardiovas- cular disease. While our results are observational and do not have enough power to show strong clinical associations, our discoveries provide an essential tool to further our understanding of involvement of the immune system in cardiovascu- lar disease. We describe the first cardiac autoantigen in the clinical context of MI and provide an important basis for further translational and clinical research in cardiac autoimmunity.}, subject = {Immunologie}, language = {en} } @phdthesis{Fleischmann2023, author = {Fleischmann, Lorena}, title = {Talent Development in Academic Domains: A Follow-Up of Former Junior Students at Julius-Maximilians-Universit{\"a}t W{\"u}rzburg}, doi = {10.25972/OPUS-30281}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302814}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The field of giftedness and gifted education has long been characterized by internal fragmentation and inconsistent definitions of core concepts (e.g., Ambrose et al., 2010; Coleman, 2006; McBee et al., 2012). It was only in recent years that increased efforts have been made to organize available research findings and thereby bring back greater uniformity to the field of giftedness and gifted education. For example, Preckel et al.'s (2020) Talent Development in Achievement Domains (TAD) framework integrates theoretical perspectives and empirical knowledge from different parts of the field. It is general in concept and can be applied to a wide range of achievement domains. By specifically focusing on measurable psychological constructs as well as their relevance at different stages of the talent development process, Preckel et al.'s (2020) TAD framework is well suited as a starting point for generating more domain-specific talent development models. The present thesis represents one of the first attempts to empirically test the validity of Preckel et al.'s (2020) TAD framework in academic domains using longitudinal data. The longitudinal data came from a sample of former junior students at Julius-Maximilians-Universit{\"a}t (JMU) W{\"u}rzburg who showed high academic achievement potential. There were two related research issues: Research Issue 1 first aimed to document in detail how the educational trajectories of former junior students unfold in the years following their Abitur. To this end, a follow-up was conducted among 208 young adults who had participated in the junior study program at JMU W{\"u}rzburg between the winter semester of 2004/2005 and the summer semester of 2011. The design of the follow-up questionnaire was based on a series of research questions that had emerged from the relevant literature on junior study programs in Germany. The follow-up ran from October 2019 to February 2020. The data were analyzed descriptively and documented as a detailed report. The results of Research Issue 1 revealed that the former junior students continued to be academically (and later professionally) successful long after their school years. For example, at the time of the follow-up, almost all former junior students had earned a bachelor's and a master's degree, most often with notable academic successes (e.g., scholarships, awards/prizes). In addition, more than half of those who responded had begun or already completed a doctoral degree, also recording special academic accomplishments (e.g., scientific publications, scholarships). A significant proportion of the former junior students had already entered the workforce at the time of their response. A look at their current professional situation revealed an above-average expression of success indicators (e.g., income, professional status). The clear majority of the former junior students reported that, even in retrospect, they would choose to take part in the junior study program at JMU W{\"u}rzburg again. Research Issue 2 aimed to determine the extent to which the structure of Preckel et al.'s (2020) TAD framework could be empirically validated in academic domains. The educational trajectories of 84 former junior students at JMU W{\"u}rzburg who had chosen a subject from the same subject field in their regular studies as in their junior studies served as the data basis. The educational trajectories were compiled from the former junior students' follow-up data and from their data on the selection process for the junior study program at JMU W{\"u}rzburg. Combining the structural assumptions of Preckel et al.'s (2020) TAD framework with relevant insights from individual academic disciplines made it possible to derive hypotheses regarding potential predictors and indicators of the talent development stages aptitude, competence, and expertise in academic domains. Structural equation models were used for data analysis. The results of Research Issue 2 suggested that the talent development stages aptitude, competence, and expertise, while being predictive of each other in their chronological order, could be satisfactorily modeled using framework-compliant indicators in academic domains. In comparison, the talent development stage transformational achievement could not (yet) be modeled based on the longitudinal data. Among the hypothesized predictors, former junior students' investigative interests and their metacognitive abilities reliably determined the talent development stages competence and expertise, whereas the remaining predictors did not make significant contributions. Taken together, the results of the present thesis suggest that the validity of Preckel et al.'s (2020) TAD framework can only be partially confirmed in academic domains. Unlike the postulated indicators, the predictors in Preckel et al.'s (2020) TAD framework do not seem to be easily generalizable to academic domains but to be highly specific with regard to the talent domain under consideration. Therefore, a natural progression of the present thesis would be to examine the structure of Preckel et al.'s (2020) TAD framework at the subordinate level of subject fields or even at the level of individual academic disciplines, for example.}, subject = {Hochbegabung}, language = {en} } @phdthesis{Maier2023, author = {Maier, Sophia Edith}, title = {Mapping membrane receptor distribution on resting platelets combining Expansion Microscopy and fluorescence confocal microscopy}, doi = {10.25972/OPUS-30031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300317}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Stroke and myocardial infarction are the most prominent and severe consequences of pathological thrombus formation. For prevention and/or treatment of thrombotic events there is a variety of anti-coagulation and antiplatelet medication that all have one side effect in common: the increased risk of bleeding. To design drugs that only intervene in the unwanted aggregation process but do not disturb general hemostasis, it is crucial to decipher the exact clotting pathway which has not been fully understood yet. Platelet membrane receptors play a vital role in the clotting pathway and, thus, the aim of this work is to establish a method to elucidate the interactions, clustering, and reorganization of involved membrane receptors such as GPIIb/IIIa and GPIX as part of the GPIb-IX-V complex. The special challenges regarding visualizing membrane receptor interactions on blood platelets are the high abundancy of the first and the small size of the latter (1—3µm of diameter). The resolution limit of conventional fluorescence microscopy and even super-resolution approaches prevents the successful differentiation of densely packed receptors from one another. Here, this issue is approached with the combination of a recently developed technique called Expansion Microscopy (ExM). The image resolution of a conventional fluorescence microscope is enhanced by simply enlarging the sample physically and thus pulling the receptors apart from each other. This method requires a complex sample preparation and holds lots of obstacles such as variable or anisotropic expansion and low images contrast. To increase ExM accuracy and sensitivity for interrogating blood platelets, it needs optimized sample preparation as well as image analysis pipelines which are the main part of this thesis. The colocalization results show that either fourfold or tenfold expanded, resting platelets allow a clear distinction between dependent, clustered, and independent receptor organizations compared to unexpanded platelets.Combining dual-color Expansion and confocal fluorescence microscopy enables to image in the nanometer range identifying GPIIb/IIIa clustering in resting platelets - a pattern that may play a key role in the clotting pathway}, language = {en} } @article{ScheinerDaunkeSeideletal.2023, author = {Scheiner, Christin and Daunke, Andrea and Seidel, Alexandra and Mittermeier, Sabrina and Romanos, Marcel and K{\"o}lch, Michael and Buerger, Arne}, title = {LessStress - how to reduce stress in school: evaluation of a universal stress prevention in schools: study protocol of a cluster-randomised controlled trial}, series = {Trials}, volume = {24}, journal = {Trials}, number = {1}, doi = {10.1186/s13063-022-06970-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300393}, year = {2023}, abstract = {Background Chronic stress is detrimental to health, and children and young people have had to cope with significantly more stress since the start of the COVID-19 pandemic. In particular, stress at school and in relation to learning is a major problem in this age group. Studies in Germany have indicated that the pandemic has led to a reduced quality of life (QoL) and an increased risk for psychiatric disorders in children and adolescents. Schools are an ideal setting for interventions against stress, which is one of the strongest predictors for the development of psychosocial problems. The present study seeks to address stress by means of a short prevention training programme in schools, including emotion regulation, mindfulness, and self-compassion. In addition to information material for self-study, students should have the opportunity to actively deal with the topic of stress and develop coping strategies within a short space of time. In contrast to very long stress reduction programmes that often last several weeks, the programme is delivered in just 90 min. Methods The effectiveness of the short and economical prevention programme LessStress will be examined in a cluster-randomised controlled trial (RCT) encompassing 1894 students. At several measurement time points, students from two groups (intervention and control) will be asked about their subjectively perceived stress levels, among other aspects. Due to the clustered nature of the data, mainly multilevel analyses will be performed. Discussion In Germany, there are no nationwide universal prevention programmes for students against stress in schools, and this gap has become more evident since the outbreak of the pandemic. Universal stress prevention in schools may be a starting point to promote resilience. By dealing with stress in a healthy way, mental health can be strengthened and maintained. Moreover, to reach at-risk students at an early stage, we advocate for a stronger networking between child psychiatry and schools.}, language = {en} } @article{Klug2023, author = {Klug, Florian}, title = {The Theologian's Socratic Role in today's Scientific World}, series = {Doctrine \& Life}, volume = {73}, journal = {Doctrine \& Life}, number = {2}, issn = {0012-4664}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-303554}, pages = {35-45}, year = {2023}, abstract = {In the scientific search for truth, the correspondence theory is predominant to decipher what counts as true. In this approach, scientific knowledge becomes empirically demonstrable and thus enclosed to the sphere of immanence. However, in theology's approach to question the given status of being human and the world's development as creation, theology does not adhere to answers that are contained within the sphere of demonstrable knowledge or mundanity, and thereby theology presents a fundamentally different conception of truth, Jesus Christ the living truth. In opposition to drawing on empirical proof, I want to reread Christian theology in a Socratic manner that employs irony to question overly simple methodologies and seek further insights what it means to be human and be engaged in the scientific search for truth if the authority of knowledge does not lie within humanity's grasp. In doing so, theology's role is an annoying, yet necessary irritation within the field of today's academia.}, language = {en} } @phdthesis{Fuhr2023, author = {Fuhr, Viktoria}, title = {Target Identification and Validation in Ibrutinib-treated Mantle Cell Lymphoma}, doi = {10.25972/OPUS-31059}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310595}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Ibrutinib serves as an efficient second-line therapy in relapsed/refractory mantle cell lymphoma. However, resistance to the BTK inhibitor results in a poor prognosis for patients. Since the mechanisms leading to resistance in initially responding tumor cells are poorly understood, this work aimed to decipher acquired features in ibrutinib-surviving cells of a sensitive mantle cell lymphoma cell line and evaluate these potential therapeutic targets in ibrutinib-treated mantle cell lymphoma. Time-resolved single-cell RNA sequencing was performed to track the transcriptomic evolution of REC-1 cells across 6 and 48 hours of treatment. Single-cell analysis uncovered a subpopulation of REC-1 with potentially greater aggressiveness and survival advantage by benefiting from interaction with the tumor microenvironment. Upregulation of B-cell receptor genes, elevated surface antigen expression of CD52 and metabolic rewiring to higher dependence on oxidative phosphorylation were identified as further potential resistance features of ibrutinib-surviving cells. RNA sequencing after prolonged incubation corroborated the increase in CD52 and oxidative phosphorylation as dominant characteristics of the cells surviving the 4-day treatment, highlighting their potential as therapeutic targets in combination with ibrutinib treatment. Concomitant use of ibrutinib and the oxidative phosphorylation inhibitor IACS-010759 increased toxicity compared to ibrutinib monotherapy due to higher apoptosis and greater inhibition of proliferation. For anti-CD52 therapy, a consecutive approach with ibrutinib pretreatment followed by incubation of surviving cells with a CD52 monoclonal antibody and human serum yielded a synergistic effect, as ibrutinib-surviving mantle cell lymphoma cells were rapidly depleted by complement-dependent cytotoxicity. Regarding the effects on primary tumor cells from mantle cell lymphoma patients, ibrutinib induced upregulation of CD52 in some cases, and increased toxicity of anti-CD52 therapy was observed in ibrutinib-sensitive patient samples after pretreatment with the BTK inhibitor. The likely favorable in vivo efficacy of an anti-CD52 therapy might therefore be restricted to a subgroup of mantle cell lymphoma patients, also in view of the associated side effects. Given the need for new therapeutic options in mantle cell lymphoma to overcome resistance to ibrutinib, this work highlights the potentially beneficial use of an oxidative phosphorylation inhibitor as add-on therapy. In addition, the findings suggest to further assess the value of anti-CD52 therapy as consolidation to ibrutinib in ibrutinib-sensitive patients with elevated CD52 surface levels on tumor cells to target resistant clones and minimize risk of minimal residual disease and relapse.}, subject = {B-Zell-Lymphom}, language = {en} } @phdthesis{Boehm2023, author = {B{\"o}hm, Christoph}, title = {Thermal Stability of the Polyesters PCL and PLGA during Melt Electrowriting}, doi = {10.25972/OPUS-30613}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-306139}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The focus of this thesis was to investigate how PCL and PLGA react to the heat exposure that comes with the MEW process over a defined timespan. To assess the thermal stability of PCL during MEW over 25 d, an automated collection of fibers has been used to determine the CTS on each day of heating for three different temperatures. PCL is exceptionally stable over 25 d at 75 °C, whereas for 85 °C and 95 °C a slight upward trend during the last 10 d could be observed, which is an indication for thermal degradation. Same trend could be observed for diameter of fibers produced at a fixed collector speed. For all temperatures, CTS during the first 5 d decreased due to inhomogeneities of the melt. Physical analysis of the fibers by XRD and mechanical testing showed no significant changes. To investigate the chemical details of the thermal durability, PCL was artificially aged over 25 d at 75 °C, 85 °C and 95 °C. Data from GPC analysis and rheology revealed that PCL is degrading steadily at all three temperatures. Combined with GC-MS analysis, two different mechanisms for degradation could be observed: random chain scission and unzipping. Additional GPC experiment using a mixture of PCL and a fluorescence labelled PCL showed that PCL was undergoing ester interchange reactions, which could explain its thermal stability. PLGA was established successfully as material for MEW. GPC results revealed that PLGA degraded heavily in the one-hour preheating period. To reduce the processing temperature, ATEC was blended with PLGA in three mixtures. This slowed down degradation and a processing window of 6 h could be established. Mechanical testing with fibers produced with PLGA and all three blends was performed. PLGA was very brittle, whereas the blends showed an elastic behavior. This could be explained by ester interchange reactions that formed a loosely crosslinked network with ATEC.}, subject = {Degradation}, language = {en} } @phdthesis{Gold2023, author = {Gold, Lukas}, title = {Methods for the state estimation of lithium-ion batteries}, doi = {10.25972/OPUS-30618}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-306180}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {This work introduced the reader to all relevant fields to tap into an ultrasound-based state of charge estimation and provides a blueprint for the procedure to achieve and test the fundamentals of such an approach. It spanned from an in-depth electrochemical characterization of the studied battery cells over establishing the measurement technique, digital processing of ultrasonic transmission signals, and characterization of the SoC dependent property changes of those signals to a proof of concept of an ultrasound-based state of charge estimation. The State of the art \& theoretical background chapter focused on the battery section on the mechanical property changes of lithium-ion batteries during operation. The components and the processes involved to manufacture a battery cell were described to establish the fundamentals for later interrogation. A comprehensive summary of methods for state estimation was given and an emphasis was laid on mechanical methods, including a critical review of the most recent research on ultrasound-based state estimation. Afterward, the fundamentals of ultrasonic non-destructive evaluation were introduced, starting with the sound propagation modes in isotropic boundary-free media, followed by the introduction of boundaries and non-isotropic structure to finally approach the class of fluid-saturated porous media, which batteries can be counted to. As the processing of the ultrasonic signals transmitted through lithium-ion battery cells with the aim of feature extraction was one of the main goals of this work, the fundamentals of digital signal processing and methods for the time of flight estimation were reviewed and compared in a separate section. All available information on the interrogated battery cell and the instrumentation was collected in the Experimental methods \& instrumentation chapter, including a detailed step-by-step manual of the process developed in this work to create and attach a sensor stack for ultrasonic interrogation based on low-cost off-the-shelf piezo elements. The Results \& discussion chapter opened with an in-depth electrochemical and post-mortem interrogation to reverse engineer the battery cell design and its internal structure. The combination of inductively coupled plasma-optical emission spectrometry and incremental capacity analysis applied to three-electrode lab cells, constructed from the studied battery cell's materials, allowed to identify the SoC ranges in which phase transitions and staging occur and thereby directly links changes in the ultrasonic signal properties with the state of the active materials, which makes this work stand out among other studies on ultrasound-based state estimation. Additional dilatometer experiments were able to prove that the measured effect in ultrasonic time of flight cannot originate from the thickness increase of the battery cells alone, as this thickness increase is smaller and in opposite direction to the change in time of flight. Therefore, changes in elastic modulus and density have to be responsible for the observed effect. The construction of the sensor stack from off-the-shelf piezo elements, its electromagnetic shielding, and attachment to both sides of the battery cells was treated in a subsequent section. Experiments verified the necessity of shielding and its negligible influence on the ultrasonic signals. A hypothesis describing the metal layer in the pouch foil to be the transport medium of an electrical coupling/distortion between sending and receiving sensor was formulated and tested. Impedance spectroscopy was shown to be a useful tool to characterize the resonant behavior of piezo elements and ensure the mechanical coupling of such to the surface of the battery cells. The excitation of the piezo elements by a raised cosine (RCn) waveform with varied center frequency in the range of 50 kHz to 250 kHz was studied in the frequency domain and the influence of the resonant behavior, as identified prior by impedance spectroscopy, on waveform and frequency content was evaluated to be uncritical. Therefore, the forced oscillation produced by this excitation was assumed to be mechanically coupled as ultrasonic waves into the battery cells. The ultrasonic waves transmitted through the battery cell were recorded by piezo elements on the opposing side. A first inspection of the raw, unprocessed signals identified the transmission of two main wave packages and allowed the identification of two major trends: the time of flight of ultrasonic wave packages decreases with the center frequency of the RCn waveform, and with state of charge. These trends were to be assessed further in the subsequent sections. Therefore, methods for the extraction of features (properties) from the ultrasonic signals were established, compared, and tested in a dedicated section. Several simple and advanced thresholding methods were compared with envelope-based and cross-correlation methods to estimate the time of flight (ToF). It was demonstrated that the envelope-based method yields the most robust estimate for the first and second wave package. This finding is in accordance with the literature stating that an envelope-based method is best suited for dispersive, absorptive media [204], to which lithium-ion batteries are counted. Respective trends were already suggested by the heatmap plots of the raw signals vs. RCn frequency and SoC. To enable such a robust estimate, an FIR filter had to be designed to preprocess the transmitted signals and thereby attenuate frequency components that verifiably lead to a distorted shape of the envelope. With a robust ToF estimation method selected, the characterization of the signal properties ToF and transmitted energy content (EC) was performed in-depth. A study of cycle-to-cycle variations unveiled that the signal properties are affected by a long rest period and the associated relaxation of the multi-particle system "battery cell" to equilibrium. In detail, during cycling, the signal properties don't reach the same value at a given SoC in two subsequent cycles if the first of the two cycles follows a long rest period. In accordance with the literature, a break-in period, making up for more than ten cycles post-formation, was observed. During this break-in period, the mechanical properties of the system are said to change until a steady state is reached [25]. Experiments at different C-rate showed that ultrasonic signal properties can sense the non-equilibrium state of a battery cell, characterized by an increasing area between charge and discharge curve of the respective signal property vs. SoC plot. This non-equilibrium state relaxes in the rest period following the discharge after the cut-off voltage is reached. The relaxation in the rest period following the charge is much smaller and shows little C-rate dependency as the state is prepared by constant voltage charging at the end of charge voltage. For a purely statistical SoC estimation approach, as employed in this work, where only instantaneous measurements are taken into account and the historic course of the measurement is not utilized as a source of information, the presence of hysteresis and relaxation leads to a reduced estimation accuracy. Future research should address this issue or even utilize the relaxation to improve the estimation accuracy, by incorporating historic information, e.g., by using the derivative of a signal property as an additional feature. The signal properties were then tested for their correlation with SoC as a function of RCn frequency. This allowed identifying trends in the behavior of the signal properties as a function of RCn frequency and C-rate in a condensed fashion and thereby enabled to predict the frequency range, about 50 kHz to 125 kHz, in which the course of the signal properties is best suited for SoC estimation. The final section provided a proof of concept of the ultrasound-based SoC estimation, by applying a support vector regression (SVR) to before thoroughly studied ultrasonic signal properties, as well as current and battery cell voltage. The included case study was split into different parts that assessed the ability of an SVR to estimate the SoC in a variety of scenarios. Seven battery cells, prepared with sensor stacks attached to both faces, were used to generate 14 datasets. First, a comparison of self-tests, where a portion of a dataset is used for training and another for testing, and cross-tests, which use the dataset of one cell for training and the dataset of another for testing, was performed. A root mean square error (RMSE) of 3.9\% to 4.8\% SoC and 3.6\% to 10.0\% SoC was achieved, respectively. In general, it was observed that the SVR is prone to overestimation at low SoCs and underestimation at high SoCs, which was attributed to the pronounced hysteresis and relaxation of the ultrasonic signal properties in this SoC ranges. The fact that higher accuracy is achieved, if the exact cell is known to the model, indicates that a variation between cells exists. This variation between cells can originate from differences in mechanical properties as a result of production variations or from differences in manual sensor placement, mechanical coupling, or resonant behavior of the ultrasonic sensors. To mitigate the effect of the cell-to-cell variations, a test was performed, where the datasets of six out of the seven cells were combined as training data, and the dataset of the seventh cell was used for testing. This reduced the spread of the RMSE from (3.6 - 10.0)\% SoC to (5.9 - 8.5)\% SoC, respectively, once again stating that a databased approach for state estimation becomes more reliable with a large data basis. Utilizing self-tests on seven datasets, the effect of additional features on the state estimation result was tested. The involvement of an additional feature did not necessarily improve the estimation accuracy, but it was shown that a combination of ultrasonic and electrical features is superior to the training with these features alone. To test the ability of the model to estimate the SoC in unknown cycling conditions, a test was performed where the C-rate of the test dataset was not included in the training data. The result suggests that for practical applications it might be sufficient to perform training with the boundary of the use cases in a controlled laboratory environment to handle the estimation in a broad spectrum of use cases. In comparison with literature, this study stands out by utilizing and modifying off-the-shelf piezo elements to equip state-of-the-art lithium-ion battery cells with ultrasonic sensors, employing a range of center frequencies for the waveform, transmitted through the battery cell, instead of a fixed frequency and by allowing the SVR to choose the frequency that yields the best result. The characterization of the ultrasonic signal properties as a function of RCn frequency and SoC and the assignment of characteristic changes in the signal properties to electrochemical processes, such as phase transitions and staging, makes this work unique. By studying a range of use cases, it was demonstrated that an improved SoC estimation accuracy can be achieved with the aid of ultrasonic measurements - thanks to the correlation of the mechanical properties of the battery cells with the SoC.}, subject = {Lithium-Ionen-Akkumulator}, language = {en} } @article{KressEgenolfSommeretal.2023, author = {Kreß, Luisa and Egenolf, Nadine and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan}, title = {Cytokine expression profiles in white blood cells of patients with small fiber neuropathy}, series = {BMC Neuroscience}, volume = {24}, journal = {BMC Neuroscience}, number = {1}, doi = {10.1186/s12868-022-00770-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300619}, year = {2023}, abstract = {Background The role of cytokines in the pathophysiology, diagnosis, and prognosis of small fiber neuropathy (SFN) is incompletely understood. We studied expression profiles of selected pro- and anti-inflammatory cytokines in RNA from white blood cells (WBC) of patients with a medical history and a clinical phenotype suggestive for SFN and compared data with healthy controls. Methods We prospectively recruited 52 patients and 21 age- and sex-matched healthy controls. Study participants were characterized in detail and underwent complete neurological examination. Venous blood was drawn for routine and extended laboratory tests, and for WBC isolation. Systemic RNA expression profiles of the pro-inflammatory cytokines interleukin (IL)-1ß, IL-2, IL-8, tumor necrosis factor-alpha (TNF) and the anti-inflammatory cytokines IL-4, IL-10, transforming growth factor beta-1 (TGF) were analyzed. Protein levels of IL-2, IL-8, and TNF were measured in serum of patients and controls. Receiver operating characteristic (ROC)-curve analysis was used to determine the accuracy of IL-2, IL-8, and TNF in differentiating patients and controls. To compare the potential discriminatory efficacy of single versus combined cytokines, equality of different AUCs was tested. Results WBC gene expression of IL-2, IL-8, and TNF was higher in patients compared to healthy controls (IL-2: p = 0.02; IL-8: p = 0.009; TNF: p = 0.03) and discriminated between the groups (area under the curve (AUC) ≥ 0.68 for each cytokine) with highest diagnostic accuracy reached by combining the three cytokines (AUC = 0.81, sensitivity = 70\%, specificity = 86\%). Subgroup analysis revealed the following differences: IL-8 and TNF gene expression levels were higher in female patients compared to female controls (IL-8: p = 0.01; TNF: p = 0.03). The combination of TNF with IL-2 and TNF with IL-2 and IL-8 discriminated best between the study groups. IL-2 was higher expressed in patients with moderate pain compared to those with severe pain (p = 0.02). Patients with acral pain showed higher IL-10 gene expression compared to patients with generalized pain (p = 0.004). We further found a negative correlation between the relative gene expression of IL-2 and current pain intensity (p = 0.02). Serum protein levels of IL-2, IL-8, and TNF did not differ between patients and controls. Conclusions We identified higher systemic gene expression of IL-2, IL-8, and TNF in SFN patients than in controls, which may be of potential relevance for diagnostics and patient stratification.}, language = {en} } @phdthesis{Nordblom2023, author = {Nordblom, Noah Frieder}, title = {Synthese und Evaluation von Gephyrinsonden f{\"u}r hochaufl{\"o}sende Mikroskopieverfahren}, doi = {10.25972/OPUS-30230}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302300}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {This decade saw the development of new high-end light microscopy approaches. These technologies are increasingly used to expand our understanding of cellular function and the molecular mechanisms of life and disease. The precision of state-of-the-art super resolution microscopy is limited by the properties of the applied fluorescent label. Here I describe the synthesis and evaluation of new functional fluorescent probes that specifically stain gephyrin, universal marker of the neuronal inhibitory post-synapse. Selected probe precursor peptides were synthesised using solid phase peptide synthesis and conjugated with selected super resolution capable fluorescent dyes. Identity and purity were defined using chromatography and mass spectrometric methods. To probe the target specificity of the resulting probe variants in cellular context, a high-throughput assay was established. The established semi-automated and parallel workflow was used for the evaluation of three selected probes by defining their co-localization with the expressed fluorescent target protein. My work provided NN1Dc and established the probe as a visualisation tool for essentially background-free visualisation of the synaptic marker protein gephyrin in a cellular context. Furthermore, NN1DA became part of a toolbox for studying the inhibitory synapse ultrastructure and brain connectivity and turned out useful for the development of a label-free, high-throughput protein interaction quantification assay.}, subject = {Fluoreszenzmikroskopie}, language = {en} } @incollection{Heisters2023, author = {Heisters, Anne}, title = {Women as Other? - Women and Other}, series = {Global Cultural Studies? Engaged Scholarship between National and Transnational Frames}, booktitle = {Global Cultural Studies? Engaged Scholarship between National and Transnational Frames}, editor = {Jetter, Tobias}, publisher = {W{\"u}rzburg University Press}, address = {W{\"u}rzburg}, doi = {10.25972/WUP-978-3-95826-207-2-59}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305875}, publisher = {W{\"u}rzburg University Press}, pages = {59-72}, year = {2023}, abstract = {No abstract available.}, subject = {Feminismus}, language = {en} } @incollection{Rishi2023, author = {Rishi, Tushar}, title = {Marxism and Contemporary Cultural Studies}, series = {Global Cultural Studies? Engaged Scholarship between National and Transnational Frames}, booktitle = {Global Cultural Studies? Engaged Scholarship between National and Transnational Frames}, editor = {Jetter, Tobias}, publisher = {W{\"u}rzburg University Press}, address = {W{\"u}rzburg}, doi = {10.25972/WUP-978-3-95826-207-2-79}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-305882}, publisher = {W{\"u}rzburg University Press}, pages = {79-85}, year = {2023}, abstract = {No abstract available.}, subject = {Kulturwissenschaften}, language = {en} } @techreport{VomhoffGeisslerGebertetal.2023, type = {Working Paper}, author = {Vomhoff, Viktoria and Geissler, Stefan and Gebert, Steffen and Hossfeld, Tobias}, title = {Towards Understanding the Global IPX Network from an MVNO Perspective}, series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)}, journal = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)}, doi = {10.25972/OPUS-32212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322121}, pages = {4}, year = {2023}, abstract = {In this paper, we work to understand the global IPX network from the perspective of an MVNO. In order to do this, we provide a brief description of the global architecture of mobile carriers. We provide initial results with respect to mapping the vast and complex interconnection network enabling global roaming from the point of view of a single MVNO. Finally, we provide preliminary results regarding the quality of service observed under global roaming conditions.}, language = {en} } @article{DresenLeeHilletal.2023, author = {Dresen, Ellen and Lee, Zheng-Yii and Hill, Aileen and Notz, Quirin and Patel, Jayshil J. and Stoppe, Christian}, title = {History of scurvy and use of vitamin C in critical illness: A narrative review}, series = {Nutrition in Clinical Practice}, volume = {38}, journal = {Nutrition in Clinical Practice}, number = {1}, doi = {10.1002/ncp.10914}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318176}, pages = {46 -- 54}, year = {2023}, abstract = {In 1747, an important milestone in the history of clinical research was set, as the Scottish surgeon James Lind conducted the first randomized controlled trial. Lind was interested in scurvy, a severe vitamin C deficiency which caused the death of thousands of British seamen. He found that a dietary intervention with oranges and lemons, which are rich in vitamin C by nature, was effective to recover from scurvy. Because of its antioxidative properties and involvement in many biochemical processes, the essential micronutrient vitamin C plays a key role in the human biology. Moreover, the use of vitamin C in critical illness—a condition also resulting in death of thousands in the 21st century—has gained increasing interest, as it may restore vascular responsiveness to vasoactive agents, ameliorate microcirculatory blood flow, preserve endothelial barriers, augment bacterial defense, and prevent apoptosis. Because of its redox potential and powerful antioxidant capacity, vitamin C represents an inexpensive and safe antioxidant, with the potential to modify the inflammatory cascade and improve clinical outcomes of critically ill patients. This narrative review aims to update and provide an overview on the role of vitamin C in the human biology and in critically ill patients, and to summarize current evidence on the use of vitamin C in diverse populations of critically ill patients, in specific focusing on patients with sepsis and coronavirus disease 2019.}, language = {en} } @article{RackeveiKarnkowskaWolf2023, author = {Rackevei, Antonia S. and Karnkowska, Anna and Wolf, Matthias}, title = {18S rDNA sequence-structure phylogeny of the Euglenophyceae (Euglenozoa, Euglenida)}, series = {Journal of Eukaryotic Microbiology}, volume = {70}, journal = {Journal of Eukaryotic Microbiology}, number = {2}, doi = {10.1111/jeu.12959}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311896}, year = {2023}, abstract = {The phylogeny of Euglenophyceae (Euglenozoa, Euglenida) has been discussed for decades with new genera being described in the last few years. In this study, we reconstruct a phylogeny using 18S rDNA sequence and structural data simultaneously. Using homology modeling, individual secondary structures were predicted. Sequence-structure data are encoded and automatically aligned. Here, we present a sequence-structure neighbor-joining tree of more than 300 taxa classified as Euglenophyceae. Profile neighbor-joining was used to resolve the basal branching pattern. Neighbor-joining, maximum parsimony, and maximum likelihood analyses were performed using sequence-structure information for manually chosen subsets. All analyses supported the monophyly of Eutreptiella, Discoplastis, Lepocinclis, Strombomonas, Cryptoglena, Monomorphina, Euglenaria, and Colacium. Well-supported topologies were generally consistent with previous studies using a combined dataset of genetic markers. Our study supports the simultaneous use of sequence and structural data to reconstruct more accurate and robust trees. The average bootstrap value is significantly higher than the average bootstrap value obtained from sequence-only analyses, which is promising for resolving relationships between more closely related taxa.}, language = {en} } @article{KernerKraussMaihoffetal.2023, author = {Kerner, Janika M. and Krauss, Jochen and Maihoff, Fabienne and Bofinger, Lukas and Classen, Alice}, title = {Alpine butterflies want to fly high: Species and communities shift upwards faster than their host plants}, series = {Ecology}, volume = {104}, journal = {Ecology}, number = {1}, doi = {10.1002/ecy.3848}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312015}, year = {2023}, abstract = {Despite sometimes strong codependencies of insect herbivores and plants, the responses of individual taxa to accelerating climate change are typically studied in isolation. For this reason, biotic interactions that potentially limit species in tracking their preferred climatic niches are ignored. Here, we chose butterflies as a prominent representative of herbivorous insects to investigate the impacts of temperature changes and their larval host plant distributions along a 1.4-km elevational gradient in the German Alps. Following a sampling protocol of 2009, we revisited 33 grassland plots in 2019 over an entire growing season. We quantified changes in butterfly abundance and richness by repeated transect walks on each plot and disentangled the direct and indirect effects of locally assessed temperature, site management, and larval and adult food resource availability on these patterns. Additionally, we determined elevational range shifts of butterflies and host plants at both the community and species level. Comparing the two sampled years (2009 and 2019), we found a severe decline in butterfly abundance and a clear upward shift of butterflies along the elevational gradient. We detected shifts in the peak of species richness, community composition, and at the species level, whereby mountainous species shifted particularly strongly. In contrast, host plants showed barely any change, neither in connection with species richness nor individual species shifts. Further, temperature and host plant richness were the main drivers of butterfly richness, with change in temperature best explaining the change in richness over time. We concluded that host plants were not yet hindering butterfly species and communities from shifting upwards. However, the mismatch between butterfly and host plant shifts might become a problem for this very close plant-herbivore relationship, especially toward higher elevations, if butterflies fail to adapt to new host plants. Further, our results support the value of conserving traditional extensive pasture use as a promoter of host plant and, hence, butterfly richness.}, language = {en} } @article{FrickeRedlichZhangetal.2023, author = {Fricke, Ute and Redlich, Sarah and Zhang, Jie and Benjamin, Caryl S. and Englmeier, Jana and Ganuza, Cristina and Haensel, Maria and Riebl, Rebekka and Rojas-Botero, Sandra and Tobisch, Cynthia and Uhler, Johannes and Uphus, Lars and Steffan-Dewenter, Ingolf}, title = {Earlier flowering of winter oilseed rape compensates for higher pest pressure in warmer climates}, series = {Journal of Applied Ecology}, volume = {60}, journal = {Journal of Applied Ecology}, number = {2}, doi = {10.1111/1365-2664.14335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312562}, pages = {365 -- 375}, year = {2023}, abstract = {Global warming can increase insect pest pressure by enhancing reproductive rates. Whether this translates into yield losses depends on phenological synchronisation of pests with their host plants and natural enemies. Simultaneously, landscape composition may mitigate climate effects by shaping the resource availability for pests and their antagonists. Here, we study the combined effects of temperature and landscape composition on pest abundances, larval parasitism, crop damage and yield, while also considering crop phenology, to identify strategies for sustainable management of oilseed rape (OSR) pests under warming climates. In all, 29 winter OSR crop fields were investigated in different climates (defined by multi-annual mean temperature, MAT) and landscape contexts in Bavaria, Germany. We measured abundances of adult pollen beetles and stem weevil larvae, pollen beetle larval parasitism, bud loss, stem damage and seed yield, and calculated the flowering date from growth stage observations. Landscape parameters (proportion of non-crop and OSR area, change in OSR area relative to the previous year) were calculated at six spatial scales (0.6-5 km). Pollen beetle abundance increased with MAT but to different degrees depending on the landscape context, that is, increased less strongly when OSR proportions were high (1-km scale), interannually constant (5-km scale) or both. In contrast, stem weevil abundance and stem damage did not respond to landscape composition nor MAT. Pollen beetle larval parasitism was overall low, but occasionally exceeded 30\% under both low and high MAT and with reduced OSR area (0.6-km scale). Despite high pollen beetle abundance in warm climates, yields were high when OSR flowered early. Thereby, higher temperatures favoured early flowering. Only among late-flowering OSR crop fields yield was higher in cooler than warmer climates. Bud loss responded analogously. Landscape composition did not substantially affect bud loss and yield. Synthesis and applications: Earlier flowering of winter OSR compensates for higher pollen beetle abundance in warmer climates, while interannual continuity of OSR area prevents high pollen beetle abundance in the first place. Thus, regional coordination of crop rotation and crop management promoting early flowering may contribute to sustainable pest management in OSR under current and future climatic conditions.}, language = {en} } @techreport{NavadeMaileGerman2023, type = {Working Paper}, author = {Navade, Piyush and Maile, Lisa and German, Reinhard}, title = {Multiple DCLC Routing Algorithms for Ultra-Reliable and Time-Sensitive Applications}, series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)}, journal = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)}, doi = {10.25972/OPUS-32217}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322177}, pages = {4}, year = {2023}, abstract = {This paper discusses the problem of finding multiple shortest disjoint paths in modern communication networks, which is essential for ultra-reliable and time-sensitive applications. Dijkstra's algorithm has been a popular solution for the shortest path problem, but repetitive use of it to find multiple paths is not scalable. The Multiple Disjoint Path Algorithm (MDPAlg), published in 2021, proposes the use of a single full graph to construct multiple disjoint paths. This paper proposes modifications to the algorithm to include a delay constraint, which is important in time-sensitive applications. Different delay constraint least-cost routing algorithms are compared in a comprehensive manner to evaluate the benefits of the adapted MDPAlg algorithm. Fault tolerance, and thereby reliability, is ensured by generating multiple link-disjoint paths from source to destination.}, language = {en} }