@phdthesis{Kasaragod2022, author = {Kasaragod, Vikram Babu}, title = {Biochemical and Structural Basis for the Moonlighting Function of Gephyrin}, doi = {10.25972/OPUS-14307}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143077}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Neurons are specialized cells dedicated to transmit the nerve impulses throughout the human body across specialized structures called synapses. At the synaptic terminals, a crosstalk between multiple macromolecules regulates the structure and function of the presynaptic nerve endings and the postsynaptic recipient sites. Gephyrin is the central organizer at inhibitory postsynaptic specializations and plays a crucial role in the organization of these structures by anchoring GABAA receptors (GABAAR) and glycine receptors (GlyR) to the postsynaptic membrane. This 93 kDa protein features an N-terminal G domain and a C-terminal E domain and the latter interacts directly with the intracellular loop between transmembrane helices 3 and 4 of certain subunits of the GlyRs and GABAARs. Biochemical and structural analyses have already provided valuable insights into the gephyrin-GlyR interaction. Interestingly, biochemical studies on the gephyrin-GABAAR interaction demonstrated that the GABAARs also depend on the same binding site as the GlyRs for the interaction with the gephyrin, but the molecular basis for this receptor specific interaction of gephyrin was still unknown. Co-crystal structures of GephE-GABAAR α3- derived peptides with supporting biochemical data presented in this study deciphered the receptor-specific interactions of gephyrin in atomic detail. In its moonlighting function, gephyrin also catalyzes the terminal step of the evolutionarily conserved molybdenum cofactor biosynthesis. Molybdenum, an essential transition element has to be complexed with a pterin-based cofactor resulting in the formation of the molybdenum cofactor (Moco). Moco is an essential component at the active site of all molybdenum-containing enzymes with the exception of nitrogenase. Mutations in enzymes involved in this pathway lead to a rare yet severe disease called Moco deficiency, which manifest itself in severe neurodevelopmental abnormalities and early childhood death. Moco biosynthesis follows a complex multistep pathway, where in the penultimate step, the N-terminal G domain of gephyrin activates the molybdopterin to form an adenylated molybdopterin intermediate. In the terminal step, this intermediate is then transferred to the C-terminal E domain of gephyrin, which catalyzes the metal insertion and deadenylation reaction to form active Moco. Previous biochemical and structural studies provided valuable insights into the penultimate step of the Moco biosynthesis but the terminal step remained elusive. Through the course of my dissertation, I crystallized the C-terminal E domain in the apo-form as well as in complex with ADP and AMP. These structures shed lightonto the deadenylation reaction and the formation of a ternary E-domain-ADP-Mo/W complex and thus provide structural insight into the metal insertion mechanism. Moreover, the structures also provided molecular insights into a mutation leading to Moco deficiency. Finally, ternary complexes of GephE, ADP and receptor-derived peptides provided first clues regarding the integration of gephyrin's dual functionality. In summary, during the course of the dissertation I was able to derive high resolution structural insights into the interactions between gephyrin and GABAARs, which explain the receptor-specific interaction of gephyrin and, furthermore, these studies can be extended in the future to understand GABAAR subunit-specific interactions of gephyrin. Finally, the understanding of Moco biosynthesis shed light on the molecular basis of the fatal Moco deficiency.}, subject = {Gephyrin}, language = {en} } @phdthesis{Wencker2022, author = {Wencker, Freya Dorothea Ruth}, title = {The methionine biosynthesis operon in \(Staphylococcus\) \(aureus\): Role of concerted RNA decay in transcript stability and T-box riboswitch turnover}, doi = {10.25972/OPUS-20712}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207124}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Methionine is the first amino acid of every newly synthesised protein. In combination with its role as precursor for the vital methyl-group donor S-adenosylmethionine, methionine is essential for every living cell. The opportunistic human pathogen Staphylococcus aureus is capable of synthesising methionine de novo, when it becomes scarce in the environment. All genes required for the de novo biosynthesis are encoded by the metICFE-mdh operon, except for metX. Expression is controlled by a hierarchical network with a methionyl-tRNA-specific T-box riboswitch (MET-TBRS) as centrepiece, that is also referred to as met leader (RNA). T-box riboswitches (TBRS) are regulatory RNA elements located in the 5'-untranslated region (5'-UTR) of genes. The effector molecule of T-box riboswitches is uncharged cognate tRNA. The prevailing mechanism of action is premature termination of transcription of the nascent RNA in the absence of the effector (i.e. uncharged cognate tRNA) due to formation of a hairpin structure, the Terminator stem. In presence of the effector, a transient stabilisation of the alternative structure, the Antiterminator, enables transcription of the downstream genes ('read-through'). Albeit, after the read-through the thermodynamically more stable Terminator eventually forms. The Terminator and the Antiterminator are two mutually exclusive structures. Previous work of the research group showed that in staphylococci the MET-TBRS ensures strictly methionine-dependent control of met operon expression. Uncharged methionyl-tRNA that activates the system is only present in sufficient amounts under methionine-deprived conditions. In contrast to other bacterial TBRS, the staphylococcal MET-TBRS has some characteristic features regarding its length and predicted secondary structure whose relevance for the function are yet unkown. Aim of the present thesis was to experimentally determine the structure of the met leader RNA and to investigate the stability of the met operon-specific transcripts in the context of methionine biosynthesis control. Furthermore, the yet unknown function of the mdh gene within the met operon was to be determined. In the context of this thesis, the secondary structure of the met leader was determined employing in-line probing. The structural analysis revealed the presence of almost all highly conserved T-box riboswitch structural characteristics. Furthermore, three additional stems, absent in all T-box riboswitches analysed to date, could be identified. Particularly remarkable is the above average length of the Terminator stem which renders it a potential target of the double-strand-specific endoribonuclease III (RNase III). The RNase III-dependent cleavage of the met leader could be experimentally verified by the use of suitable mutants. Moreover, the exact cleavage site within the Terminator was determined. The unusual immediate separation of the met leader from the met operon mRNA via the RNase III cleavage within the Terminator stem induces the rapid degradation of the met leader RNA and, most likely, that of the 5'-region of the met mRNA. The met mRNA is degraded from its 5'-end by the exoribonuclease RNase J. The stability of the met mRNA was found to vary over the length of the transcript with an instable 5'-end (metI and metC) and a longer half-life towards the 3'-end (metE and mdh). The varying transcript stability is reflected by differences in the available cellular protein levels. The obtained data suggest that programmed mRNA degradation is another level of regulation in the complex network of staphylococcal de novo methionine biosynthesis control. In addition, the MET-TBRS was studied with regard to a future use as a drug target for novel antimicrobial agents. To this end, effects of a dysregulated methionine biosynthesis on bacterial growth and survival were investigated in met leader mutants that either caused permanent transcription of the met operon ('ON') or prevented operon transcription ('OFF'), irrespective of the methionine status in the cell. Methionine deprivation turned out to be a strong selection pressure, as 'OFF' mutants acquired adaptive mutations within the met leader to restore met operon expression that subsequently re-enabled growth. The second part of the thesis was dedicated to the characterisation of the Mdh protein that is encoded by the last gene of the met operon and whose function is unknown yet. At first, co-transcription and -expression with the met operon could be demonstrated. Next, the Mdh protein was overexpressed and purified and the crystal structure of Mdh was solved to high resolution by the Kisker research group (Rudolf-Virchow-Zentrum W{\"u}rzburg). Analysis of the structure revealed the amino acid residues crucial for catalytic activity, and zinc was identified as a co-factor of Mdh. Also, Mdh was shown to exist as a dimer. However, identification of the Mdh substrate was, in the context of this thesis, (still) unsuccessful. Nevertheless, interactions of Mdh with enzymes of the met operon could be demonstrated by employing the bacterial two-hybrid system. This fact and the high conservation of mdh/Mdh on nucleotide and amino acid level among numerous staphylococcal species suggests an important role of Mdh within the methionine metabolism that should be a worthwhile subject of future research.}, subject = {Staphylococcus aureus}, language = {en} } @phdthesis{Lisowski2022, author = {Lisowski, Clivia}, title = {Maturation of the \(Salmonella\) containing vacuole is compromised in G1 arrested host cells}, doi = {10.25972/OPUS-18523}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-185239}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The interaction of bacterial pathogens and the human host is a complex process that has shaped both organisms on a molecular, cellular and population level. When pathogenic bacteria infect the human body, a battle ensues between the host immune system and the pathogen. In order to escape an immune response and to colonize the host, pathogenic bacteria have developed diverse virulence strategies and some pathogens even replicate within host cells. For survival and propagation within the dynamic environment of a host cell, these bacteria interfere with the regulation of host pathways, such as the cell cycle, for their own benefit. The intracellular pathogen Salmonella Typhimurium invades eukaryotic cells and resides and replicates in a modified vacuolar compartment in which it is protected from the innate immune response. To this end, it employs a set of virulence factors that help to invade cells (SPI-1 effectors) and to hijack and modify the host endolysosomal system, in order to stabilize and mature its vacuolar niche (SPI-2 effectors). Previous studies have shown that Salmonella arrests host cells in G2/M phase and that Salmonella infected cells progress faster from G1 into S phase, suggesting that the G1 phase is disadvantageous for Salmonella infection. In fact, it has already been observed that Salmonella replication is impaired in G1 arrested cells. However, the reason for this impairment remained unclear. The current study addressed this question for the first time and revealed that the highly adapted, intracellular lifestyle of Salmonella is drastically altered upon G1 arrest of the host cell. It is shown that proteasomal degradation in G1 arrested cells is delayed and endolysosomal and autophagosomal trafficking is compromised. Accordingly, processing of lysosomal proteins is insufficient and lysosomal activity is decreased; resulting in uneven distribution and accumulation of endolysosomes and autophagosomes, containing undegraded cargo. The deregulation of these cellular signaling pathways affects maturation of the Salmonella containing vacuole (SCV). For the first time it is shown that acidification of SCVs is impaired upon G1 arrest. Thus, an important environmental factor for the switch from SPI-1 to SPI-2 gene expression is missing and the SPI-2 system is not activated. Consequently, targeting and modification of host cell structures by SPI-2 effectors e.g. recruitment of endolysosomal membrane proteins, like LAMP1, or exchange of endosomal cargo, is compromised. In addition, degradation of Salmonella SPI-1 effectors by the host proteasome is delayed. Their prolonged presence sustained the recruitment of early endosomes and contributed to the SCV remaining in an early, vulnerable maturation stage. Finally, it was shown that SCV membrane integrity is compromised; the early SCV ruptures and bacteria are released into the cytoplasm. Depending on the host cell type, SPI-2 independent, cytoplasmic replication is promoted. This might favor bacterial spreading, dissemination into the tissue and provide an advantage in host colonization. Overall, the present study establishes a link between host cell cycle regulation and the outcome of Salmonella infection. It fills the gap of knowledge as to why the host cell cycle stage is of critical importance for Salmonella infection and sheds light on a key aspect of host-pathogen interaction.}, subject = {Salmonella Typhimurium}, language = {en} } @phdthesis{Wallstabe2022, author = {Wallstabe, Lars}, title = {Development and preclinical evaluation of tumour-reactive T cells expressing a chemically programmable chimeric antigen receptor}, doi = {10.25972/OPUS-17907}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179071}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The genetic modification of T cells for the expression a chimeric antigen receptor (CAR) endows them with a new specificity for an antigen. Adoptive immunotherapy with CD19-CAR T cells has achieved high rates of sustained complete remissions in B cell malignancies. However, the downregulation or loss of the targeted antigen after mono-specific CAR T cell therapy, e.g. against CD19 or CD22, has been reported. Targeting multiple antigens on tumour cells, sequentially or simultaneously, could overcome this limitation. Additionally, targeting multiple antigens with CAR T cells could drive the translation from hematologic malignancies to prevalent solid cancers, which often express tumour-associated antigens heterogeneously. We hypothesised that expression of a universal CAR, which can be programmed with hapten-like molecules, could endow T cells with specificities for multiple antigens. In this study we introduce a novel chemically programmable CAR (cpCAR) based on monoclonal antibody h38C2. Our data show, that cpCARs form a reversible chemical bond to molecules containing a diketone-group and therefore can be programmed to acquire multiple specificities. We programmed cpCAR T cells with hapten-like compounds against integrins αvβ3 and α4β1 as well as the folate receptor. We observed tumour cell lysis, IFN ɣ and IL-2 production and proliferation of programmed cpCAR T cells against tumour cells expressing the respective target antigen in vitro. As a reference to cpCARs programmed against αvβ3, we further introduced novel conventional αvβ3-CARs. These CARs, based on humanised variants of monoclonal antibody LM609 (hLM609), directly bind to integrin αvβ3 via their scFv. The four αvβ3-CAR constructs comprised either an scFv with higher affinity (hLM609v7) or lower affinity (hLM609v11) against αvβ3 integrin and either a long (IgG4 hinge, CH2, CH3) or short (IgG4 hinge) extracellular spacer. We selected the hLM609v7-CAR with short spacer, which showed potent anti-tumour reactivity both in vitro and in a murine xenograft model, for comparison with the cpCAR programmed against αvβ3. Our data show specific lysis of αvβ3-positive tumour cells, cytokine production and proliferation of both hLM609-CAR T cells and cpCAR T cells in vitro. However, conventional hLM609-CAR T cells mediated stronger anti-tumour effects compared to cpCAR T cells in the same amount of time. In line with the in vitro data, complete destruction of tumour lesions in a murine melanoma xenograft model was only observed for mice treated with conventional αvβ3-CAR T cells. Collectively, we introduce a cpCAR, which can be programmed against multiple tumour antigens, and hLM609-CARs specific for the integrin αvβ3. The cpCAR technology bears the potential to counteract current limitations, e.g. antigen loss, of current monospecific CAR T cell therapy. Targeting αvβ3 integrin with CAR T cells could have clinical applications in the treatment of solid malignancies, because αvβ3 is not only expressed on a variety of solid malignancies, but also on tumour-associated vasculature and fibroblast.}, subject = {Tumorimmunologie}, language = {en} } @phdthesis{Chen2022, author = {Chen, Mengjia}, title = {Right Ventricular Dysfunction contributes to Left Ventricular Thrombus Formation in Patients post Anterior Myocardial Infarction}, doi = {10.25972/OPUS-20414}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204149}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Our current data demonstrate that besides the known risk factors, including apical aneurysm, reduced left ventricular longitudinal systolic function (MAPSE) and advanced diastolic dysfunction, Right ventricular dysfunction as determined by reduced tricuspid annular plane systolic excursion (TAPSE) or right ventricular fractional area change (RV_FAC) is independently associated with left ventricular thrombus formation in acute anterior myocardial infarction patients, especially in the setting of anterior myocardial infarction without the formation of an apical aneurysm. This study suggests that besides left ventricular abnormalities, right ventricular dysfunction likewise contributes LVT formation in patients with acute anterior myocardial infarction.}, subject = {Thrombus}, language = {en} } @phdthesis{Heib2022, author = {Heib, Tobias}, title = {The role of Rho GTPases in megakaryopoiesis and thrombopoiesis}, doi = {10.25972/OPUS-21664}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216645}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Platelets, derived from megakaryocytes (MKs) in the bone marrow (BM), are small, anucleated cells that circulate in the bloodstream and are critical for thrombosis and hemostasis. Megakaryo- and subsequent thrombopoiesis are highly orchestrated processes involving the differentiation and maturation of MKs from hematopoietic stem cells (HSCs), after which MKs are able to release platelets into the bloodstream, a process termed proplatelet formation (PPF). Here, the MK penetrates the endothelial lining and releases cytoplasmic portions (proplatelets) into the blood stream, which finally mature into platelets within the ciruculation. PPF requires an extensive crosstalk as well as a tight regulation of the MK cytoskeleton, in which small GTPases of the Rho family, such as RhoA and Cdc42 are critically involved and play opposing roles. MK and platelet specific Cdc42 or RhoA-deficiency in mice results in macrothrombocytopenia. Moreover, RhoA deficient mice displayed a frequent mislocalization of entire MKs into BM sinusoids, a finding that was reverted upon concomitant lack of Cdc42 but accompanied by an aggravated macrothrombocytopenia. Whether receptors are involved in the process of transendothelial MK migration, however, remained unclear. In the first part of this thesis, a centrifugation-based method ('spin isolation') to harvest murine BM cells was established, which not only reduces experimental time, costs and animals but is also highly suitable for studies on primary and in vitro cultured BM-derived cells. The spin isolation was used particularly for MK studies during the course of the thesis. In the second part of this thesis, a MK- and platelet-specific RhoA/Cdc42 double-deficiency was shown to result in reduced expression of a variety of MK-specific glycoproteins and cytoskeletal regulators of importance during MK maturation and PPF, a phenotype culminating in virtually abolished platelet biogenesis. We thus uncovered that RhoA/Cdc42-regulated gene expression is a prerequisite for cytoplasmic MK maturation, but dispensable for endomitosis. In the third part of this thesis we analyzed mice double-deficient in RhoA and prominent MK receptors which are potentially involved in the regulation of PPF in the BM environment. We were able to show that integrins as well as the inhibitory receptor G6b-B are dispensable for transendothelial migration of RhoA-deficient MKs. Surprisingly however, the myelofibrosis and concomitant osteosclerosis observed in G6b-B single-deficient mice was attenuated in RhoA/G6b B double-deficient mice, thus implying an important role of RhoA during myelofibrotic disease progression. BM transplantation experiments furthermore revealed that not only the macrothrombocytopenia but also the transmigration of RhoA-deficient MKs is due to cell-intrinsic defects and not related to possible Pf4-Cre off-target effects in non-hematopoietic cells. In the last part of this study we demonstrated that the new approach for MK- and platelet-specific gene ablatation using Gp1ba-Cre deleter mice is associated with intrinsic MK defects and in addition results in insufficient depletion of RhoA compared to the Pf4-Cre model, positioning the latter still as the gold standard for studying MK biology.}, subject = {Megakaryozyt}, language = {en} } @phdthesis{Guentzel2022, author = {G{\"u}ntzel, Paul Mathias}, title = {Bioinspired Ion Pairs Transforming Poorly Water-soluble Compounds into Protic Ionic Liquids and Deep Eutectic Solvents}, doi = {10.25972/OPUS-21980}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219806}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Microbial, mammalian and plant cells produce and contain secondary metabolites, which typically are soluble in water to prevent cell damage by crystallization. The formation of ion pairs, e.g. with carboxylic acids or mineral acids, is a natural blueprint to keep basic metabolites in solution. It was aimed at showing whether the mostly large carboxylates form soluble protic ionic liquids (PILs) with basic natural products resulting in enhanced aqueous solubility. Furthermore, their supramolecular pattern in aqueous solution was studied. Thereby, naturally occurring carboxylic acids were identified being appropriate counterions for natural basic compounds and facilitate the formation of PILs with their beneficial characteristics, like improved dissolution rate and enhanced apparent solubility.}, subject = {Ionic Liquids}, language = {en} } @phdthesis{Toksabay2022, author = {Toksabay, Sinem}, title = {Synthesis and on surface self assembly properties of pi extended tribenzotriquinacenes}, doi = {10.25972/OPUS-24573}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245734}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Tribenzotriquinacene (TBTQ) is a polycyclic aromatic framework with a particularly rigid, C3v symmetrical, bowl-shaped core bearing three mutually fused indane wings. It has been discussed as a defect center for a nanographene by Kuck and colleagues. Therefore, extended TBTQ structures are promising models for saturated defect structures in graphene and graphene like molecules and could be used to investigate the role of defects for the electronic properties of graphene. With this motivation, three different pi-extended TBTQ derivatives have been synthesized in this work. Several different Scholl reaction conditions were tried to obtain fully annulated product of hexaphenyl substituted TBTQ. The desired benzannulated TBTQ derivative could not be obtained due to unfavourable electron density in the respective positions of the molecule and increased reactivity of the bay position of the precursor. As an another method for benzannulation is the on-surface synthesis of graphene flakes and can be carried out using electron beams e.g. in a tunneling microscope (STM). According to our previous research, the parent system TBTQ and centro-methyl TBTQ on silver and gold surfaces showed that the gas phase deposition of these molecules gives rise to the formation of highly ordered two-dimensional assemblies with unique structural features. This shows the feasibility for the formation of defective graphene networks starting from the parent structures. Therefore, the same deposition technique was used to deposit Me-TBTQ(OAc)3Ph6, and investigate the molecular self-assembly properties directly on the surface of Cu (111). In summary, the substrate temperature dependent self-assembly of Me-TBTQ(OAc)3Ph6 molecules on Cu(111), shows the following evolution of orientations. At room temperature, molecules form dimers, which construct a higher-coverage honeycomb lattice. Furthermore, one of the acetyl group located in the bay positions of the TBTQ core is cleaved and the remaining two induce the metal-molecule interaction. It was presumed that by increasing the temperature to 393 K, the remaining acetyl and methyl groups would beeliminated from the molecular structure.In addition, the smaller TBTQ-Ph6 molecules preferably lie flat on Cu(111) crystal and allowing the molecules to settle into a C3-symmetry and form a dense hexagonal structure.}, subject = {Triquinacenderivate}, language = {en} } @phdthesis{Fey2022, author = {Fey, Christina}, title = {Establishment of an intestinal tissue model for pre-clinical screenings}, doi = {10.25972/OPUS-24410}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244107}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The small intestine represents a strong barrier separating the lumen from blood circulation thereby playing a major role in the absorption and the transport of pharmacological agents prior to their arrival on the respective target site. In order to gain more knowledge about specialized uptake mechanisms and risk assessment for the patient after oral admission of drugs, intestinal in vitro models demonstrating a close similarity to the in vivo situation are needed. In the past, cell line-based in vitro models composed of Caco-2 cells cultured on synthetic cell carriers represented the "gold standard" in the field of intestinal tissue engineering. Expressive advantages of these models are a reproducible, cost-efficient and standardized model set up, but cell function can be negatively influenced by the low porosity or unwanted molecular adhesion effects of the artificial scaffold material. Natural extracellular matrices (ECM) such as the porcine decellularized small intestinal submucosa (SIS) are used as alternative to overcome some common drawbacks; however, the fabrication of these scaffolds is time- and cost-intensive, less well standardized and the 3Rs (replacement, reduction, refinement) principle is not entirely fulfilled. Nowadays, biopolymer-based scaffolds such as the bacterial nanocellulose (BNC) suggest an interesting option of novel intestinal tissue engineered models, as the BNC shows comparable features to the native ECM regarding fiber arrangement and hydrophilic properties. Furthermore, the BNC is of non-animal origin and the manufacturing process is faster as well as well standardized at low costs. In this context, the first part of this thesis analyzed the BNC as alternative scaffold to derive standardized and functional organ models in vitro. Therefore, Caco-2 cells were cultured on two versions of BNC with respect to their surface topography, the unmodified BNC as rather smooth surface and the surface-structured BNC presenting an aligned fiber arrangement. As controls, Caco-2 in vitro models were set up on PET and SIS matrices. In this study, the BNC-based models demonstrated organ-specific properties comprising typical cellular morphologies, a characteristic tight junction protein expression profile, representative ultrastructural features and the formation of a tight epithelial barrier together with a corresponding transport activity. In summary, these results validated the high quality of the BNC-based Caco-2 models under cost-efficient conditions and their suitability for pre-clinical research purposes. However, the full functional diversity of the human intestine cannot be presented by Caco-2 cells due to their tumorigenic background and their exclusive representation of mature enterocytes. Next to the scaffold used for the setup of in vitro models, the cellular unit mainly drives functional performance, which demonstrates the crucial importance of mimicking the cellular diversity of the small intestine in vitro. In this context, intestinal primary organoids are of high interest, as they show a close similarity to the native epithelium regarding their cellular diversity comprising enterocytes, goblet cells, enteroendocrine cells, paneth cells, transit amplifying cells and stem cells. In general, such primary organoids grow in a 3D Matrigel® based environment and a medium formulation supplemented with a variety of growth factors to maintain stemness, to inhibit differentiation and to stimulate cell migration supporting long term in vitro culture. Intestinal primary spheroid/organoid cultures were set up as Transwell®-like models on both BNC variants, which resulted in a fragmentary cell layer and thereby unfavorable properties of these scaffold materials under the applied circumstances. As the BNC manufacturing process is highly flexible, surface properties could be adapted in future studies to enable a good cell adherence and barrier formation for primary intestinal cells, too. However, the application of these organoid cultures in pre-clinical research represents an enormous challenge, as the in vitro culture is complex and additionally time- and cost-intensive. With regard to the high potential of primary intestinal spheroids/organoids and the necessity of a simplified but predictive model in pre-clinical research purposes, the second part of this thesis addressed the establishment of a primary-derived immortalized intestinal cell line, which enables a standardized and cost-efficient culture (including in 2D), while maintaining the cellular diversity of the organoid in vitro cultures. In this study, immortalization of murine and human intestinal primary organoids was induced by ectopic expression of a 10- (murine) or 12 component (human) pool of genes regulating stemness and the cell cycle, which was performed in cooperation with the InSCREENeX GmbH in a 2D- and 3D-based transduction strategy. In first line, the established cell lines (cell clones) were investigated for their cell culture prerequisites to grow under simplified and cost-efficient conditions. While murine cell clones grew on uncoated plastic in a medium formulation supplemented with EGF, Noggin, Y-27632 and 10\% FCS, the human cell clones demonstrated the necessity of a Col I pre coating together with the need for a medium composition commonly used for primary human spheroid/organoid cultures. Furthermore, the preceding analyses resulted in only one human cell clone and three murine cell clones for ongoing characterization. Studies regarding the proliferative properties and the specific gene as well as protein expression profile of the remaining cell clones have shown, that it is likely that transient amplifying cells (TACs) were immortalized instead of the differentiated cell types localized in primary organoids, as 2D, 3D or Transwell®-based cultures resulted in slightly different gene expression profiles and in a dramatically reduced mRNA transcript level for the analyzed marker genes representative for the differentiated cell types of the native epithelium. Further, 3D cultures demonstrated the formation of spheroid-like structures; however without forming organoid-like structures due to prolonged culture, indicating that these cell populations have lost their ability to differentiate into specific intestinal cell types. The Transwell®-based models set up of each clone exhibit organ-specific properties comprising an epithelial-like morphology, a characteristic protein expression profile with an apical mucus-layer covering the villin-1 positive cell layer, thereby representing goblet cells and enterocytes, together with representative tight junction complexes indicating an integer epithelial barrier. The proof of a functional as well as tight epithelial barrier in TEER measurements and in vivo-like transport activities qualified the established cell clones as alternative cell sources for tissue engineered models representing the small intestine to some extent. Additionally, the easy handling and cell expansion under more cost-efficient conditions compared to primary organoid cultures favors the use of these newly generated cell clones in bioavailability studies. Altogether, this work demonstrated new components, structural and cellular, for the establishment of alternative in vitro models of the small intestinal epithelium, which could be used in pre-clinical screenings for reproducible drug delivery studies.}, subject = {D{\"u}nndarm}, language = {en} } @phdthesis{Mueller2022, author = {M{\"u}ller, Stefan}, title = {Coherent Multiple-Quantum Multidimensional Fluorescence Spectroscopy}, doi = {10.25972/OPUS-24411}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244113}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This thesis describes novel concepts for the measurement of the static and dynamic properties of the electronic structure of molecules and nanocrystals in the liquid phase by means of coherent fluorescence-detected spectroscopy in two and three frequency dimensions. These concepts are based on the systematic variation ("phase cycling") of a sequence of multiple time-delayed femtosecond excitation pulses in order to decode a multitude of novel nonlinear signals from the resulting phase-dependent fluorescence signal. These signals represent any permutation of correlations between zero-, one-, two-, and three-quantum coherences. To this end, two new phase-cycling schemes have been developed which can simultaneously resolve and discriminate several nonlinear signals of sixth order, including those of the fourth order of nonlinearity. By means of the sixth-order signals recorded in this work, static properties of highly excited electronic states in molecules such as their energies, transition dipole moments, and relative displacement of electronic potential surfaces, as well as dynamic properties in terms of their relaxation kinetics, can be ascertained. Furthermore, it was shown that these signals are suitable for the characterization of exciton-exciton correlations in colloidal quantum dots and for the measurement of ultrafast exciton-exciton annihilation in molecular aggregates. The experiments performed in this thesis mark an important step towards the complete characterization of the nonlinear response of quantum systems. In view of this, the concept of fluorescence-detected multiple-quantum coherence multidimensional spectroscopy introduced here offers a unified, systematic approach. In virtue of the technical advantages such as the use of a single excitation beam and the absence of nonresonant contributions, the measurement protocols developed here can be directly transferred to other incoherent observables and to sample systems in other states of matter. Furthermore, the approaches presented here can be systematically extended to higher frequency dimensions and higher orders of nonlinearity.}, subject = {Coherent Multidimensional Spectroscopy}, language = {en} } @phdthesis{Hagspiel2022, author = {Hagspiel, Stephan Alexander}, title = {Synthesis and Reactivity of Pseudohalide-substituted Boranes and Borylenes}, doi = {10.25972/OPUS-24945}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249459}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This work involves the synthesis and reactivity of pseudohalide-substituted boranes and borylenes. A series of compounds of the type (CAAC)BR2Y (CAAC = cyclic alkyl(amino)carbene; R = H, Br; Y = CN, NCS, PCO) were prepared first. The two-electron reduction of (CAAC)BBr2Y (Y = CN, NCS) in the presence of a second Lewis base L (L = N-heterocyclic carbene) resulted in the formation of the corresponding doubly Lewis base-stabilized pseudohaloborylenes (CAAC)(L)BY. These borylenes show versatile reactivity patterns, including their oxidation to the corresponding radical cations, coordination via the respective pseudohalide substituent to group 6 metal carbonyl complexes, as well as a boron-centered protonation with Br{\o}nsted acids to boronium cations. Reduction of (CAAC)BBr2(NCS) in the absence of a second donor ligand, led to the formation of boron-doped thiazolothiazoles via reductive dimerization of two isothiocyanatoborylenes. These B,N,S-heterocycles possess a low degree of aromaticity as well as interesting photophysical properties and can furthermore be protonated as well as hydroborated. Additionally, CAAC adducts of the parent boraphosphaketene (CAAC)BH2(PCO) could be prepared, which readily reacted with boroles [Ph4BR'] (R' = aryl) via decarbonylation in a ring expansion reaction. The obtained 1,2-phosphaborinines represent B,P-isosteres of benzene and consequently could be coordinated to metal carbonyl complexes of the chromium triade via η6-coordination, resulting in new half-sandwich complexes thereof.}, subject = {Borylene}, language = {en} } @phdthesis{Dombrovski2022, author = {Dombrovski, Veaceslav}, title = {Software Framework to Support Operations of Nanosatellite Formations}, isbn = {978-3-945459-38-6}, doi = {10.25972/OPUS-24931}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249314}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Since the first CubeSat launch in 2003, the hardware and software complexity of the nanosatellites was continuosly increasing. To keep up with the continuously increasing mission complexity and to retain the primary advantages of a CubeSat mission, a new approach for the overall space and ground software architecture and protocol configuration is elaborated in this work. The aim of this thesis is to propose a uniform software and protocol architecture as a basis for software development, test, simulation and operation of multiple pico-/nanosatellites based on ultra-low power components. In contrast to single-CubeSat missions, current and upcoming nanosatellite formation missions require faster and more straightforward development, pre-flight testing and calibration procedures as well as simultaneous operation of multiple satellites. A dynamic and decentral Compass mission network was established in multiple active CubeSat missions, consisting of uniformly accessible nodes. Compass middleware was elaborated to unify the communication and functional interfaces between all involved mission-related software and hardware components. All systems can access each other via dynamic routes to perform service-based M2M communication. With the proposed model-based communication approach, all states, abilities and functionalities of a system are accessed in a uniform way. The Tiny scripting language was designed to allow dynamic code execution on ultra-low power components as a basis for constraint-based in-orbit scheduler and experiment execution. The implemented Compass Operations front-end enables far-reaching monitoring and control capabilities of all ground and space systems. Its integrated constraint-based operations task scheduler allows the recording of complex satellite operations, which are conducted automatically during the overpasses. The outcome of this thesis became an enabling technology for UWE-3, UWE-4 and NetSat CubeSat missions.}, subject = {Kleinsatellit}, language = {en} } @phdthesis{Kryven2022, author = {Kryven, Myroslav}, title = {Optimizing Crossings in Circular-Arc Drawings and Circular Layouts}, isbn = {978-3-95826-174-7}, doi = {10.25972/WUP-978-3-95826-175-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245960}, school = {Universit{\"a}t W{\"u}rzburg}, pages = {viii, 129}, year = {2022}, abstract = {A graph is an abstract network that represents a set of objects, called vertices, and relations between these objects, called edges. Graphs can model various networks. For example, a social network where the vertices correspond to users of the network and the edges represent relations between the users. To better see the structure of a graph it is helpful to visualize it. The research field of visualizing graphs is called Graph Drawing. A standard visualization is a node-link diagram in the Euclidean plane. In such a representation the vertices are drawn as points in the plane and edges are drawn as Jordan curves between every two vertices connected by an edge. Edge crossings decrease the readability of a drawing, therefore, Crossing Optimization is a fundamental problem in Graph Drawing. Graphs that can be drawn with few crossings are called beyond-planar graphs. The topic that deals with definition and analysis of beyond-planar graphs is called Beyond Planarity and it is an important and relatively new research area in Graph Drawing. In general, beyond planar graphs posses drawings where edge crossings are restricted in some way. For example, the number of crossings may be bounded by a constant independent of the size of the graph. Crossings can also be restricted locally by, for example, restricting the number of crossings per edge, restricting the number of pairwise crossing edges, or bounding the crossing angle of two edges in the drawing from below. This PhD thesis defines and analyses beyond-planar graph classes that arise from such local restrictions on edge crossings.}, subject = {Graphenzeichnen}, language = {en} } @phdthesis{Ryma2022, author = {Ryma, Matthias}, title = {Exploiting the Thermoresponsive Properties of Poly(2-oxazoline)s for Biofabrication}, doi = {10.25972/OPUS-24746}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-247462}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In this thesis, non-modified POx, namely PnPrOx and PcycloPrOx, with an LCST in the physiological range between 20 and 37°C have been utilized as materials for three different biofabrication approaches. Their thermoresponsive behavior and processability were exploited to establish an easy-to-apply coating for cell sheet engineering, a novel method to create biomimetic scaffolds based on aligned fibrils via Melt Electrowriting (MEW) and the application of melt electrowritten sacrificial scaffolds for microchannel creation for hydrogels. Chapter 3 describes the establishment of a thermoresponsive coating for tissue culture plates. Here, PnPrOx was simply dissolved in water and dried in well plates and petri dishes in an oven. PnPrOx adsorbed to the surface, and the addition of warm media generated a cell culture compatible coating. It was shown that different cell types were able to attach and proliferate. After confluency, temperature reduction led to the detachment of cell sheets. Compared to standard procedures for surface coating, the thermoresponsive polymer is not bound covalently to the surface and therefore does not require specialized equipment and chemical knowledge. However, it should be noted that the detachment of the cell layer requires the dissolution of the PnPrOx-coating, leading to possible polymer contamination. Although it is only a small amount of polymer dissolved in the media, the detached cell sheets need to be washed by media exchange for further processing if required. ...}, subject = {Thermoresponsive Polymere}, language = {en} } @phdthesis{Lehenberger2022, author = {Lehenberger, Maximilian}, title = {Ecology and Evolution of symbiotic microbial communities in fungus farming ambrosia beetles}, publisher = {Fungal Ecology, Frontiers in Microbiology, Deutsche Gesellschaft f{\"u}r allgemeine und angewandte Entomologie}, doi = {10.25972/OPUS-24154}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241546}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Within my PhD project I gained several novel insights into the poorly investigated symbiotic world of fungus farming ambrosia beetles and their bark beetle ancestors, where I especially focused on physiological interactions and capabilities of associated fungal symbionts. Here, (i) I could confirm the association of mutualistic Phialophoropsis fungi with the ambrosia beetle genus Trypodendron and found hints for a possible new Phialophoropsis species in T. signatum and T. domesticum. Moreover, I could show that mutualistic fungi of Trypodendron ambrosia beetles are able to decompose major woody polysaccharides such as cellulose and xylan. Additionally, (ii) I provided the first images using micro-computed tomography (µCT) of the formerly unknown structure of the mycetangium of Trypodendron leave. (iii) I could confirm a general tolerance towards ethanol in mutualistic ambrosia beetle fungi, while antagonistic fungi as well as most examined fungal bark beetle associates (e.g. possibly tree-defense detoxifying species) were highly sensitive to even low concentrations of ethanol. Further, (iv) I found that natural galleries of ambrosia beetles are highly enriched with several biologically important elements (such as N, P, S, K, Mg) compared to the surrounding woody tissue and suggest that mutualistic fungi are translocating and concentrating elements from the immediate surrounding xylem to the beetles galleries. Furthermore, (v) I could show that various fungi associated with bark and ambrosia beetles (mutualists, possibly beneficial symbionts) are emitting several volatile organic compounds mostly within aliphatic and aromatic alcohols and esters, while non-mutualistic and free living species were generally emitting a lower number and amount of volatiles. Finally, especially bark and ambrosia beetle fungi were found to incorporate several amino acids, from which some are especially important for the production of certain volatile organic compounds. Amino acid content also indicated a higher nutritional value for certain species. Here, I propose that especially volatile organic compounds are widespread key players in maintaining various symbioses between fungi and beetles, as already proven by a recent study on the bark beetle Ips typographus (as well as for some other bark beetle-fungus symbioses, see summary in Kandasamy et al. 2016) and also suggested for ambrosia beetles.}, language = {en} } @phdthesis{Giampaolo2022, author = {Giampaolo, Sabrina}, title = {Role of the transcription factor NFATc1 during the early stages of thymocyte development}, doi = {10.25972/OPUS-24639}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246394}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {T lymphocytes (T cells) represent one of the major cell populations of the immune system. Named by the place of their development, the thymus, several types can be distinguished as the αβ T cells, the γδ T cells, the mucosa-associated invariant T cells (MAIT), and the natural killer T (NKT) cells. The αβ lineages of CD4+ THelper and the CD8+ T cytotoxic cells with the T cell receptor (TCR) composed of α- and β-chain are major players of the adaptive immune system. In the thymus, CD4+ and CD8+ single positive (SP) αβ cells represent the ultimate result of positive and negative selection of CD4+CD8+ double positive (DP) thymocytes. The DP population derives from the double negative (DN) thymocytes that develop from bone marrow-derived progenitors through different stages (DN1-DN4) that are characterized by CD25 and CD44 surface expression. NFATc1, a member of the Nuclear Factor of Activated T cells (NFAT) transcription factors family, is critically involved in the differentiation and function of T cells. During thymocyte development, the nuclear expression of NFATc1 reaches the highest level at the DN3 (CD44-CD25+) stage. The hematopoietic cell-specific ablation of NFATc1 activity results in an arrest of thymocyte differentiation at the DN1 (CD44+CD25-) stage. On the other hand, over-expression of a constitutively active version of NFATc1 results in an impaired transition of DN3 cells to the DN4 (CD44-CD25-) stage, suggesting that a certain threshold level of NFATc1 activity is critical at this point. ChIP-seq and RNA-seq analysis allowed us the identification of NFATc1/A target genes involved in lineage development as the Tcra and Tcrb gene loci. Furthermore, we identified multiple NFATc1-regulated genes that are involved in γδ T cell development. In the mouse models, Rag1Cre-Nfatc1fl/fl and Rag1Cre-E2fl/fl, in which the activity of NFATc1 or inducible NFATc1 in the latter is impaired during the early stages of thymocyte development, we observed increased numbers of γδ T cells. These γδ T cells showed an unusual overexpression of CD4, a lack of CD24 expression, and overexpression of the anti-apoptotic gene Bcl2a1a. We hypothesize that during the DN stages NFATc1 plays an important role in regulating crucial steps of αβ thymocyte development and when NFATc1 activity is missing this may disturb αβ development resulting in alternative cell fates like γδ T cells.}, subject = {Thymocytes}, language = {en} } @phdthesis{Kortmann2022, author = {Kortmann, Mareike}, title = {Biodiversity and recreation - Optimizing tourism and forest management in forests affected by bark beetles}, doi = {10.25972/OPUS-24031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240317}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Forests are multi-functional system, which have to fulfil different objectives at the same time. The main functions include the production of wood, storage of carbon, the promotion of biological diversity and the provision of recreational space. Yet, global forests are affected by large and intense natural disturbances, like bark beetle infestations. While natural disturbances threaten wood production and are perceived as 'catastrophe' diminishing recreational value, biodiversity can benefit from the disturbance-induced changes in forest structures. This trade-off poses a dilemma to managers of bark beetle affected stands, particularly in protected areas designated to both nature conservation and recreation. Forest landscapes need a sustainable management concept aligning these different objectives. In order to support this goal with scientific knowledge, the aim of this work is to analyse ecological and social effects along a gradient of different disturbance severities. In this context, I studied the effects of a disturbance severity gradient on the diversity of different taxonomic groups including vascular plants, mosses, lichens, fungi, arthropods and birds in five national parks in Central Europe. To analyse the recreational value of the landscape I conducted visitor surveys in the same study areas in which the biodiversity surveys were performed. To analyse possible psychological or demographic effects on preferences for certain disturbance intensities, an additional online survey was carried out.}, subject = {Borkenk{\"a}fer}, language = {en} } @phdthesis{Kuhlemann2022, author = {Kuhlemann, Alexander}, title = {Bioorthogonal labeling of neuronal proteins using super-resolution fluorescence microscopy}, doi = {10.25972/OPUS-24373}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-243731}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The synaptic cleft is of central importance for synaptic transmission, neuronal plasticity and memory and thus well studied in neurobiology. To target proteins of interest with high specificity and strong signal to noise conventional immunohistochemistry relies on the use of fluorescently labeled antibodies. However, investigations on synaptic receptors remain challenging due to the defined size of the synaptic cleft of ~20 nm between opposing pre- and postsynaptic membranes. At this limited space, antibodies bear unwanted side effects such as crosslinking, accessibility issues and a considerable linkage error between fluorophore and target of ~10 nm. With recent single molecule localization microscopy (SMLM) methods enabling localization precisions of a few nanometers, the demand for labeling approaches with minimal linkage error and reliable recognition of the target molecules rises. Within the scope of this work, different labeling techniques for super-resolution fluorescence microscopy were utilized allowing site-specific labeling of a single amino acid in synaptic proteins like kainate receptors (KARs), transmembrane α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor regulatory proteins (TARPs), γ-aminobutyric acid type A receptors (GABA-ARs) and neuroligin 2 (NL2). The method exploits the incorporation of unnatural amino acids (uAAs) in the protein of interest using genetic code expansion (GCE) via amber suppression technology and subsequent labeling with tetrazine functionalized fluorophores. Implementing this technique, hard-to-target proteins such as KARs, TARPs and GABA-ARs could be labeled successfully, which could only be imaged insufficiently with conventional labeling approaches. Furthermore, functional studies involving electrophysiological characterization, as well as FRAP and FRET experiments validated that incorporation of uAAs maintains the native character of the targeted proteins. Next, the method was transferred into primary hippocampal neurons and in combination with super-resolution microscopy it was possible to resolve the nanoscale organization of γ2 and γ8 TARPs. Cluster analysis of dSTORM localization data verified synaptic accumulation of γ2, while γ8 was homogenously distributed along the neuron. Additionally, GCE and bioorthogonal labeling allowed visualization of clickable GABA-A receptors located at postsynaptic compartments in dissociated hippocampal neurons. Moreover, saturation experiments and FRET imaging of clickable multimeric receptors revealed successful binding of multiple tetrazine functionalized fluorophores to uAA-modified dimeric GABA-AR α2 subunits in close proximity (~5 nm). Further utilization of tetrazine-dyes via super-resolution microscopy methods such as dSTORM and click-ExM will provide insights to subunit arrangement in receptors in the future. This work investigated the nanoscale organization of synaptic proteins with minimal linkage error enabling new insights into receptor assembly, trafficking and recycling, as well as protein-protein interactions at synapses. Ultimately, bioorthogonal labeling can help to understand pathologies such as the limbic encephalitis associated with GABA-AR autoantibodies and is already in application for cancer therapies.}, subject = {microscopy}, language = {en} } @phdthesis{Boetzl2022, author = {B{\"o}tzl, Fabian Alexander}, title = {The influence of crop management and adjacent agri-environmental scheme type on natural pest control in differently structured landscapes}, doi = {10.25972/OPUS-24140}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241400}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Summary Chapters I \& II: General Introduction \& General Methods Agriculture is confronted with a rampant loss of biodiversity potentially eroding ecosystem service potentials and adding up to other stressors like climate change or the consequences of land-use change and intensive management. To counter this 'biodiversity crisis', agri-environment schemes (AES) have been introduced as part of ecological intensification efforts. These AES combine special management regimes with the establishment of tailored habitats to create refuges for biodiversity in agricultural landscapes and thus ensure biodiversity mediated ecosystem services such as pest control. However, little is known about how well different AES habitats fulfil this purpose and whether they benefit ecosystem services in adjacent crop fields. Here I investigated how effective different AES habitats are for restoring biodiversity in different agricultural landscapes (Chapter V) and whether they benefit natural pest control in adjacent oilseed rape (Chapter VI) and winter cereal fields (Chapter VII). I recorded biodiversity and pest control potentials using a variety of different methods (Chapters II, V, VI \& VII). Moreover, I validated the methodology I used to assess predator assemblages and predation rates (Chapters III \& IV). Chapter III: How to record ground dwelling predators? Testing methodology is critical as it ensures scientific standards and trustworthy results. Pitfall traps are widely used to record ground dwelling predators, but little is known about how different trap types affect catches. I compared different types of pitfall traps that had been used in previous studies in respect to resulting carabid beetle assemblages. While barrier traps collected more species and deliver more complete species inventories, conventional simple pitfall traps provide reliable results with comparatively little handling effort. Placing several simple pitfall traps in the field can compensate the difference while still saving handling effort.   Chapter IV: How to record predation rates? A plethora of methods has been proposed and used for recording predation rates, but these have rarely been validated before use. I assessed whether a novel approach to record predation, the use of sentinel prey cards with glued on aphids, delivers realistic results. I compared different sampling efforts and showed that obtained predation rates were similar and could be linked to predator (carabid beetle) densities and body-sizes (a proxy often used for food intake rates). Thus, the method delivers reliable and meaningful predation rates. Chapter V: Do AES habitats benefit multi-taxa biodiversity? The main goal of AES is the conservation of biodiversity in agricultural landscapes. I investigated how effectively AES habitats with different temporal continuity fulfil this goal in differently structured landscapes. The different AES habitats investigated had variable effects on local biodiversity. Temporal continuity of AES habitats was the most important predictor with older, more temporally continuous habitats harbouring higher overall biodiversity and different species assemblages in most taxonomic groups than younger AES habitats. Results however varied among taxonomic groups and natural enemies were equally supported by younger habitats. Semi-natural habitats in the surrounding landscape and AES habitat size were of minor importance for local biodiversity and had limited effects. This stresses that newly established AES habitats alone cannot restore farmland biodiversity. Both AES habitats as well as more continuous semi-natural habitats synergistically increase overall biodiversity in agricultural landscapes. Chapter VI: The effects of AES habitats on predators in adjacent oilseed rape fields Apart from biodiversity conservation, ensuring ecosystem service delivery in agricultural landscapes is a crucial goal of AES. I therefore investigated the effects of adjacent AES habitats on ground dwelling predator assemblages in oilseed rape fields. I found clear distance decay effects from the field edges into the field centres on both richness and densities of ground dwelling predators. Direct effects of adjacent AES habitats on assemblages in oilseed rape fields however were limited and only visible in functional traits of carabid beetle assemblages. Adjacent AES habitats doubled the proportion of predatory carabid beetles indicating a beneficial role for pest control. My results show that pest control potentials are largest close to the field edges and beneficial effects are comparably short ranged. Chapter VII: The effects of AES habitats on pest control in adjacent cereal fields Whether distance functions and potential effects of AES habitats are universal across crops is unknown. Therefore, I assessed distance functions of predators, pests, predation rates and yields after crop rotation in winter cereals using the same study design as in the previous year. Resulting distance functions were not uniform and differed from those found in oilseed rape in the previous year, indicating that the interactions between certain adjacent habitats vary with habitat and crop types. Distance functions of cereal-leaf beetles (important cereal pests) and parasitoid wasps were moreover modulated by semi-natural habitat proportion in the surrounding landscapes. Field edges buffered assemblage changes in carabid beetle assemblages over crop rotation confirming their important function as refuges for natural enemies. My results emphasize the beneficial role of field edges for pest control potentials. These findings back the calls for smaller field sizes and more diverse, more heterogeneously structured agricultural landscapes. Chapter VIII: General Discussion Countering biodiversity loss and ensuring ecosystem service provision in agricultural landscapes is intricate and requires strategic planning and restructuring of these landscapes. I showed that agricultural landscapes could benefit maximally from (i) a mixture of AES habitats and semi-natural habitats to support high levels of overall biodiversity and from (ii) smaller continuously managed agricultural areas (i.e. smaller field sizes or the insertion of AES elements within large fields) to maximize natural pest control potentials in crop fields. I propose a mosaic of younger AES habitats and semi-natural habitats to support ecosystem service providers and increase edge density for ecosystem service spillover into adjacent crops. The optimal extent and density of this network as well as the location in which AES and semi-natural habitats interact most beneficially with adjacent crops need further investigation. My results provide a further step towards more sustainable agricultural landscapes that simultaneously allow biodiversity to persist and maintain agricultural production under the framework of ecological intensification.}, subject = {{\"O}kologie}, language = {en} } @phdthesis{Amatobi2022, author = {Amatobi, Kelechi Michael}, title = {Circadian clocks determine transport and membrane lipid oscillation in \(Drosophila\) hemolymph in complex interactions between nutrient-type, photic conditions and feeding behaviour}, doi = {10.25972/OPUS-24446}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244462}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The interaction between circadian clocks and metabolism is of increasing interest, since clock dysfunction often correlates with metabolic pathologies. Many research articles have been published analysing the impact of factors such as circadian clock, light, feeding time and diet-type on energy homeostasis in various tissues/organs of organisms with most of the findings done in mammals. Little is known about the impact of circadian clock and the above-mentioned factors on circulating lipids, especially the transport form of lipids - diacylglycerol (DG) and membrane lipids such as phosphatidylethanolamine (PE) and phosphatidylcholine (PC) in the Drosophila hemolymph. The fruit fly Drosophila is a prime model organism in circadian, behaviour and metabolism research. To study the role of circadian clock and behaviour in metabolism, we performed an extensive comparative hemolymph lipid (diacylglycerol: DG, phosphatidylethanolamine: PE, phosphatidylcholine: PC) analysis using ultra performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-MS) between wild-type flies (WTCS) and clock disrupted mutants (per01). In addition, clock controlled food intake- feeding behaviour was investigated. Time-dependent variation of transport (DG) and membrane lipids (PE and PC) were not rhythmic in WTCS under constant darkness and in per01 under LD, suggesting an impact of light and clock genes on daily lipid oscillations. Day-time and night-time restriction of food led to comparable lipid profiles, suggesting that lipid oscillations are not exclusively entrained by feeding but rather are endogenously regulated. Ultradian oscillations in lipid levels in WTCS under LD were masked by digested fatty acids since lipid levels peaked more robustly at the beginning and end of light phase when flies were fed a lipid- and protein-free diet. These results suggest that metabolite (DG, PE and PC) oscillation is influenced by complex interactions between nutrient-type, photic conditions, circadian clock and feeding time. In conclusion, the results of this thesis suggest that circadian clocks determine transport and membrane lipid oscillation in Drosophila hemolymph in complex interactions between nutrient-type, photic conditions and feeding behaviour.}, subject = {Pharmaceutische Biologie}, language = {en} } @phdthesis{Schindler2022, author = {Schindler, Dorothee}, title = {Water Oxidation with Multinuclear Ruthenium Catalysts}, doi = {10.25972/OPUS-23309}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233093}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In terms of the need of environmentally benign renewable and storable energy sources, splitting of water into hydrogen and oxygen by using sunlight is a promising approach. Hereby, water oxidation catalysts (WOCs) are required to perform the water oxidation comprising the transfer of four electrons to provide the reducing equivalents for producing hydrogen. The class of Ru(bda) (bda = 2,2'-bipyridine-6,6'-dicarboxylate) catalysts has proven to be efficient for this reaction. In this thesis, ligand exchange processes in Ru(bda) complexes have been analyzed and the formation of multinuclear macrocyclic WOCs was studied. Based on the knowledge acquired by these studies, new multinuclear cyclic Ru(bda) complexes have been synthesized and their catalytic efficiencies in homogeneous water oxidation have been investigated. Going one step further for setting up functional devices, molecular WOCs have been immobilized on conducting or semiconducting supporting materials. Direct anchoring on carbon nanotubes generated a promising materials for further applications.}, subject = {Rutheniumkomplexe}, language = {en} } @phdthesis{Vellmer2022, author = {Vellmer, Tim}, title = {New insights into the histone variant H2A.Z incorporation pathway in \(Trypanosoma\) \(brucei\)}, doi = {10.25972/OPUS-25796}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257960}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The histone variant H2A.Z is a key player in transcription regulation in eukaryotes. Histone acetylations by the NuA4/TIP60 complex are required to enable proper incorporation of the histone variant and to promote the recruitment of other complexes and proteins required for transcription initiation. The second key player in H2A.Z-mediated transcription is the chromatin remodelling complex SWR1, which replaces the canonical histone H2A with its variant. By the time this project started little was known about H2A.Z in the unicellular parasite Trypanosoma brucei. Like in other eukaryotes H2A.Z was exclusively found in the transcription start sites of the polycistronic transcription units where it keeps the chromatin in an open conformation to enable RNA-polymerase II-mediated transcription. Previous studies showed the variant colocalizing with an acetylation of lysine on histone H4 and a methylation of lysine 4 on histone H3. Data indicated that HAT2 is linked to H2A.Z since it is required for acetylation of lyinse 10 on histone H4. A SWR1-like complex and a complex homologous to the NuA4/TIP60 could not be identified yet. This study aimed at identifying a SWR1-like remodelling complex in T. brucei and at identifying a protein complex orthologous to NuA4/TIP60 as well as at answering the question whether HAT2 is part of this complex or not. To this end, I performed multiple mass spectrometry-coupled co-Immunoprecipitation assays with potential subunits of a SWR1 complex, HAT2 and a putative homolog of a NuA4/TIP60 subunit. In the course of these experiments, I was able to identify the TbSWR1 complex. Subsequent cell fractionation and chromatin immunoprecipitation-coupled sequencing analysis experiments confirmed, that this complex is responsible for the incorporation of the histone variant H2A.Z in T. brucei. In addition to this chromatin remodelling complex, I was also able to identify two histone acetyltransferase complexes assembled around HAT1 and HAT2. In the course of my study data were published by the research group of Nicolai Siegel that identified the histone acetyltransferase HAT2 as being responsible for histone H4 acetylation, in preparation to promote H2A.Z incorporation. The data also indicated that HAT1 is responsible for acetylation of H2A.Z. According to the literature, this acetylation is required for proper transcription initiation. Experimental data generated in this study indicated, that H2A.Z and therefore TbSWR1 is involved in the DNA double strand break response of T. brucei. The identification of the specific complex composition of all three complexes provided some hints about how they could interact with each other in the course of transcription regulation and the DNA double strand break response. A proximity labelling approach performed with one of the subunits of the TbSWR1 complex identified multiple transcription factors, PTM writers and proteins potentially involved in chromatin maintenance. Overall, this work will provide some interesting insights about the composition of the complexes involved in H2A.Z incorporation in T. brucei. Furthermore, it is providing valuable information to set up experiments that could shed some light on RNA-polymerase II-mediated transcription and chromatin remodelling in T. brucei in particular and Kinetoplastids in general.}, subject = {Chromatinremodelling}, language = {en} } @phdthesis{Reis2022, author = {Reis, Felix}, title = {Realization and Spectroscopy of the Quantum Spin Hall Insulator Bismuthene on Silicon Carbide}, doi = {10.25972/OPUS-25825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258250}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Topological matter is one of the most vibrant research fields of contemporary solid state physics since the theoretical prediction of the quantum spin Hall effect in graphene in 2005. Quantum spin Hall insulators possess a vanishing bulk conductivity but symmetry-protected, helical edge states that give rise to dissipationless charge transport. The experimental verification of this exotic state of matter in 2007 lead to a boost of research activity in this field, inspired by possible ground-breaking future applications. However, the use of the quantum spin Hall materials available to date is limited to cryogenic temperatures owing to their comparably small bulk band gaps. In this thesis, we follow a novel approach to realize a quantum spin Hall material with a large energy gap and epitaxially grow bismuthene, i.e., Bi atoms adopting a honeycomb lattice, in a \((\sqrt{3}\times\sqrt{3})\) reconstruction on the semiconductor SiC(0001). In this way, we profit both from the honeycomb symmetry as well as the large spin-orbit coupling of Bi, which, in combination, give rise to a topologically non-trivial band gap on the order of one electronvolt. An in-depth theoretical analysis demonstrates that the covalent bond between the Si and Bi atoms is not only stabilizing the Bi film but is pivotal to attain the quantum spin Hall phase. The preparation of high-quality, unreconstructed SiC(0001) substrates sets the basis for the formation of bismuthene and requires an extensive procedure in ultra-pure dry H\(_2\) gas. Scanning tunneling microscopy measurements unveil the (\(1\times1\)) surface periodicity and smooth terrace planes, which are suitable for the growth of single Bi layers by means of molecular beam epitaxy. The chemical configuration of the resulting Bi film and its oxidation upon exposure to ambient atmosphere are inspected with X-ray photoelectron spectroscopy. Angle-resolved photoelectron spectroscopy reveals the excellent agreement of probed and calculated band structure. In particular, it evidences a characteristic Rashba-splitting of the valence bands at the K point. Scanning tunneling spectroscopy probes signatures of this splitting, as well, and allows to determine the full band gap with a magnitude of \(E_\text{gap}\approx0.8\,\text{eV}\). Constant-current images and local-density-of-state maps confirm the presence of a planar honeycomb lattice, which forms several domains due to different, yet equivalent, nucleation sites of the (\(\sqrt{3}\times\sqrt{3}\))-Bi reconstruction. Differential conductivity measurements demonstrate that bismuthene edge states evolve at atomic steps of the SiC substrate. The probed, metallic local density of states is in agreement with the density of states expected from the edge state's energy dispersion found in density functional theory calculations - besides a pronounced dip at the Fermi level. By means of temperature- and energy-dependent tunneling spectroscopy it is shown that the spectral properties of this suppressed density of states are successfully captured in the framework of the Tomonaga-Luttinger liquid theory and most likely originate from enhanced electronic correlations in the edge channel.}, subject = {Zweidimensionales Material}, language = {en} } @masterthesis{Busch2022, type = {Bachelor Thesis}, author = {Busch, Marlene Corinna}, title = {Developing a virtual Control Room for future satellite missions}, doi = {10.25972/OPUS-25826}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258261}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This thesis deals with the first part of a larger project that follows the ultimate goal of implementing a software tool that creates a Mission Control Room in Virtual Reality. The software is to be used for the operation of spacecrafts and is specially developed for the unique real-time requirements of unmanned satellite missions. Beginning from launch, throughout the whole mission up to the recovery or disposal of the satellite, all systems need to be monitored and controlled in continuous intervals, to ensure the mission's success. Mission Operation is an essential part of every space mission and has been undertaken for decades. Recent technological advancements in the realm of immersive technologies pave the way for innovative methods to operate spacecrafts. Virtual Reality has the capability to resolve the physical constraints set by traditional Mission Control Rooms and thereby delivers novel opportunities. The paper highlights underlying theoretical aspects of Virtual Reality, Mission Control and IP Communication. However, the focus lies upon the practical part of this thesis which revolves around the first steps of the implementation of the virtual Mission Control Room in the Unity Game Engine. Overall, this paper serves as a demonstration of Virtual Reality technology and shows its possibilities with respect to the operation of spacecrafts.}, subject = {Control room}, language = {en} } @phdthesis{Lasway2022, author = {Lasway, Julius Vincent}, title = {Impact of human land use on bee diversity and plant-pollinator interactions in Tanzania savannah ecosystems}, doi = {10.25972/OPUS-25772}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257726}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {One of the pronounced global challenges facing ecologists is how to feed the current growing human population while sustaining biodiversity and ecosystem services. To shed light on this, I investigated the impact of human land use on bee diversity and plant-pollinator interactions in Tanzania Savannah ecosystems. The thesis comprises the following chapters: Chapter I: General Introduction This chapter provides the background information including the study objectives and hypotheses. It highlights the ecological importance of bees and the main threats facing bee pollinators with a focus on two land-use practices namely livestock grazing and agriculture. It also highlights the diversity and global distribution of bees. It further introduces the tropical savannah ecosystem, its climate, and vegetation characteristics and explains spectacular megafauna species of the system that form centers of wildlife tourism and inadequacy knowledge on pollinators diversity of the system. Finally, this chapter describes the study methodology including, the description of the study area, study design, and data collection. Chapter II: Positive effects of low livestock grazing intensity on East African bee assemblages mediated by increases in floral resources The impact of livestock grazing intensity on bee assemblage has been subjected to research over decades. Moreover, most of these studies have been conducted in temperate Europe and America leaving the huge tropical savannah of East Africa less studied. Using sweep netting and pan traps, a total of 183 species (from 2,691 individuals) representing 55 genera and five families were collected from 24 study sites representing three levels of livestock grazing intensity in savannah ecosystem of northern Tanzania. Results have shown that moderate livestock grazing slightly increased bee species richness. However, high livestock grazing intensity led to a strong decline. Besides, results revealed a unimodal distribution pattern of bee species richness and mean annual temperature. It was also found that the effect of livestock grazing and environmental temperature on bee species richness was mediated by a positive effect of moderate grazing on floral resource richness. The study, therefore, reveals that bee communities of the African savannah zone may benefit from low levels of livestock grazing as this favors the growth of flowering plant species. A high level of livestock grazing intensity will cause significant species losses, an effect that may increase with climatic warming. Chapter III: Agricultural intensification with seasonal fallow land promotes high bee diversity in Afrotropical drylands This study investigated the impact of local agriculture intensification on bee diversity in the Afro tropical drylands of northern Tanzania. Using sweep netting and pan traps, a total of 219 species (from 3,428 individuals) representing 58 genera and six families were collected from 24 study sites (distributed from 702 to 1708 m. asl) representing three levels of agriculture intensity spanning an extensive gradient of mean annual temperature. Results showed that bee species richness increased with agricultural intensity and with increasing temperature. However, the effects of agriculture intensity and temperature on bee species richness were mediated by the positive effects of agriculture and temperature on floral resource richness used by bee pollinators. Moreover, results showed that variation of bee body sizes increases with agricultural intensification, "that effect", however, diminished in environments with higher temperatures. This study reveals that bee assemblages in Afrotropical drylands benefit from agriculture intensification in the way it is currently practiced. Further intensification, including year-round irrigated crop monocultures and extensive use of agrochemicals, is likely to exert a negative impact on bee diversity and pollination services, as reported in temperate regions. Moreover, several bee species were restricted to natural savannah habitats. Therefore, to conserve bee communities in Afro tropical drylands and guarantee pollination services, a mixture of savannah and agriculture, with long periods of fallow land should be maintained. Chapter IV: Impact of land use intensification and local features on plants and pollinators in Sub-Saharan smallholder farms For the first time in the region, this study explores the impact of land-use intensification on plants and pollinators in Sub-Saharan smallholder farms. The study complemented field surveys of bees with a modern DNA metabarcoding approach to characterize the foraged plants and thus built networks describing plant-pollinator interactions at the individual insect level. This information was coupled with quantitative traits of landscape composition and floral availability surrounding each farm. The study found that pollinator richness decreased with increasing impervious and agricultural cover in the landscape, whereas the flower density at each farm correlated with pollinator richness. The intensification of agricultural land use and urbanization correlated with a higher foraging niche overlap among pollinators due to the convergence of individuals' flower-visiting strategies. Furthermore, within farms, the higher availability of floral resources drove lower niche overlap among individuals, greater abundance of flower visitors shaped higher generalization at the networks level (H2I), possibly due to increased competition. These mechanistic understandings leading to individuals' foraging niche overlap and generalism at the network level, could imply stability of interactions and the pollination ecosystem service. The integrative survey proved that plant-pollinator systems are largely affected by land use intensification and by local factors in smallholder farms of Sub-Saharan Africa. Thus, policies promoting nature-based solutions, among which the introduction of more pollinator-friendly practices by smallholder farmers, could be effective in mitigating the intensification of both urban and rural landscapes in this region, as well as in similar Sub-Saharan contexts. Chapter V: A synopsis of the Bee occurrence data of northern Tanzania This study represents a synopsis of the bee occurrence data of northern Tanzania obtained from a survey in the Kilimanjaro, Arusha, and Manyara regions. Bees were sampled using two standardized methods, sweep netting and colored pan traps. The study summed up 953 species occurrences of 45 species belonging to 20 genera and four families (Halictidae, Apidae, Megachilidae, and andrenidae) A. This study serves as the baseline information in understanding the diversity and distribution of bees in the northern parts of the country. Understanding the richness and distribution of bees is a critical step in devising robust conservation and monitoring strategies for their populations since limited taxonomic information of the existing and unidentified bee species makes their conservation haphazard. Chapter VI: General discussion In general, findings obtained in these studies suggest that livestock grazing and agriculture intensification affects bee assemblages and floral resources used by bee pollinators. Results have shown that moderate livestock grazing intensity may be important in preserving bee diversity. However, high level of livestock grazing intensity may result in a strong decline in bee species richness and abundance. Moreover, findings indicate that agriculture intensification with seasonal fallow lands supports high floral resource richness promoting high bee diversity in Afrotropical drylands. Nonetheless, natural savannahs were found to contain unique bee species. Therefore, agriculture intensification with seasonal fallow should go in hand with conserving remnant savannah in the landscapes to increase bee diversity and ensure pollination services. Likewise, findings suggest that increasing urbanization and agriculture cover at the landscape level reduce plant and pollinator biodiversity with negative impacts on their complex interactions with plants. Conversely, local scale availability of floral resources has shown the positive effects in buffering pollinators decline and mitigating all detrimental effects induced by land-use intensification. Moreover, findings suggest that the impact of human land use (livestock grazing and agriculture) do not act in isolation but synergistically interacts with climatic factors such as mean annual temperature, MAT. The impact of MAT on bee species richness in grazing gradient showed to be more detrimental than in agriculture habitats. This could probably be explained by the remaining vegetation cover following anthropogenic disturbance. Meaning that the remaining vegetation cover in the agricultural gradient probably absorbs the solar radiations hence reducing detrimental effect of mean annual temperature on bee species richness. This one is not the case in grazing gradient since the impact of livestock grazing is severe, leaving the bare land with no vegetation cover. Finally, our findings conclude that understanding the interplay of multiple anthropogenic activities and their interaction with MAT as a consequence of ongoing climate change is necessary for mitigating their potential consequences on bee assemblages and the provision of ecosystem services. Morever, future increases in livestock grazing and agriculture intensification (including year-round crop irrigated monocultures and excessive use of agrochemicals) may lead to undesirable consequences such as species loss and impair provision of pollination services.}, subject = {Human land use}, language = {en} } @article{HauptsteinForsterNadernezhadetal.2022, author = {Hauptstein, Julia and Forster, Leonard and Nadernezhad, Ali and Horder, Hannes and Stahlhut, Philipp and Groll, J{\"u}rgen and Blunk, Torsten and Teßmar, J{\"o}rg}, title = {Bioink Platform Utilizing Dual-Stage Crosslinking of Hyaluronic Acid Tailored for Chondrogenic Differentiation of Mesenchymal Stromal Cells}, series = {Macromolecular Bioscience}, volume = {22}, journal = {Macromolecular Bioscience}, number = {2}, doi = {10.1002/mabi.202100331}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257556}, pages = {2100331}, year = {2022}, abstract = {3D bioprinting often involves application of highly concentrated polymeric bioinks to enable fabrication of stable cell-hydrogel constructs, although poor cell survival, compromised stem cell differentiation, and an inhomogeneous distribution of newly produced extracellular matrix (ECM) are frequently observed. Therefore, this study presents a bioink platform using a new versatile dual-stage crosslinking approach based on thiolated hyaluronic acid (HA-SH), which not only provides stand-alone 3D printability but also facilitates effective chondrogenic differentiation of mesenchymal stromal cells. A range of HA-SH with different molecular weights is synthesized and crosslinked with acrylated (PEG-diacryl) and allylated (PEG-diallyl) polyethylene glycol in a two-step reaction scheme. The initial Michael addition is used to achieve ink printability, followed by UV-mediated thiol-ene reaction to stabilize the printed bioink for long-term cell culture. Bioinks with high molecular weight HA-SH (>200 kDa) require comparably low polymer content to facilitate bioprinting. This leads to superior quality of cartilaginous constructs which possess a coherent ECM and a strongly increased stiffness of long-term cultured constructs. The dual-stage system may serve as an example to design platforms using two independent crosslinking reactions at one functional group, which allows adjusting printability as well as material and biological properties of bioinks.}, language = {en} } @phdthesis{Janzen2022, author = {Janzen, Dieter}, title = {Functional analysis of ion channels and neuronal networks in 2D and 3D \(in\) \(vitro\) cell culture models}, doi = {10.25972/OPUS-25170}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251700}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In the central nervous system, excitatory and inhibitory signal transduction processes are mediated by presynaptic release of neurotransmitters, which bind to postsynaptic receptors. Glycine receptors (GlyRs) and GABAA receptors (GABAARs) are ligand-gated ion channels that enable synaptic inhibition. One part of the present thesis elucidated the role of the GlyRα1 β8 β9 loop in receptor expression, localization, and function by means of amino acid substitutions at residue Q177. This residue is underlying a startle disease phenotype in the spontaneous mouse model shaky and affected homozygous animals are dying 4-6 weeks after birth. The residue is located in the β8 β9 loop and thus part of the signal transduction unit essential for proper ion channel function. Moreover, residue Q177 is involved in a hydrogen network important for ligand binding. We observed no difference in ion channel trafficking to the cellular membrane for GlyRα1Q177 variants. However, electrophysiological measurements demonstrated reduced glycine, taurine, and β alanine potency in comparison to the wildtype protein. Modeling revealed that some GlyRα1Q177 variants disrupt the hydrogen network around residue Q177. The largest alterations were observed for the Q177R variant, which displayed similar effects as the Q177K mutation present in shaky mice. Exchange with structurally related amino acids to the original glutamine preserved the hydrogen bond network. Our results underlined the importance of the GlyR β8 β9 loop for proper ion channel gating. GlyRs as well as GABAARs can be modulated by numerous allosteric substances. Recently, we focused on monoterpenes from plant extracts and showed positive allosteric modulation of GABAARs. Here, we focused on the effect of 11 sesquiterpenes and sesquiterpenoids (SQTs) on GABAARs. SQTs are compounds naturally occurring in plants. We tested SQTs of the volatile fractions of hop and chamomile, including their secondary metabolites generated during digestion. Using the patch-clamp technique on transfected cells and neurons, we were able to observe significant GABAAR modulation by some of the compounds analyzed. Furthermore, a possible binding mechanism of SQTs to the neurosteroid binding site of the GABAAR was revealed by modeling and docking studies. We successfully demonstrated GABAAR modulation by SQTs and their secondary metabolites. The second part of the thesis investigated three-dimensional (3D) in vitro cell culture models which are becoming more and more important in different part of natural sciences. The third dimension allows developing of complex models closer to the natural environment of cells, but also requires materials with mechanical and biological properties comparable to the native tissue of the encapsulated cells. This is especially challenging for 3D in vitro cultures of primary neurons and astrocytes as the brain is one of the softest tissues found in the body. Ultra-soft matrices that mimic the neuronal in vivo environment are difficult to handle. We have overcome these challenges using fiber scaffolds created by melt electrowriting to reinforce ultra-soft matrigel. Hence, the scaffolds enabled proper handling of the whole composites and thus structural and functional characterizations requiring movement of the composites to different experimental setups. Using these scaffold-matrigel composites, we successfully established methods necessary for the characterization of neuronal network formation. Before starting with neurons, a mouse fibroblast cell line was seeded in scaffold-matrigel composites and transfected with the GlyR. 3D cultured cells displayed high viability, could be immunocytochemically stained, and electrophysiologically analyzed. In a follow-up study, primary mouse cortical neurons in fiber-reinforced matrigel were grown for up to 21 days in vitro. Neurons displayed high viability, and quantification of neurite lengths and synapse density revealed a fully formed neuronal network already after 7 days in 3D culture. Calcium imaging and patch clamp experiments demonstrated spontaneous network activity, functional voltage-gated sodium channels as well as action potential firing. By combining ultra-soft hydrogels with fiber scaffolds, we successfully created a cell culture model suitable for future work in the context of cell-cell interactions between primary cells of the brain and tumor cells, which will help to elucidate the molecular pathology of aggressive brain tumors and possibly other disease mechanisms.}, subject = {Zellkultur}, language = {en} } @phdthesis{Vyalkova2022, author = {Vyalkova, Anna}, title = {Efficacy of approved Smallpox Vaccines in Human and Canine Cancer Therapy: Adipose - tissue derived Stem Cells (ADSC) take up VACV and serve as a protective vehicle for virus delivery to tumors}, doi = {10.25972/OPUS-25345}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-253457}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Cancer is one of the major causes of mortality in developed countries. In 2020, there were more than 19.3 million new cases of tumor malignancies worldwide, with more than 10 million deaths. The high rates of cancer cases and mortality necessitate extensive research and the development of novel cancer treatments and antitumor agents. In most cases, conventional treatment strategies for tumor therapy are based on chemotherapeutic treatment, which is supplemented with radiotherapy and/or surgical resection of solid tumors [1]. The use of chemotherapy for the treatment of cancer has significant side effects, the most dangerous of which is toxicity [2] [3]. Modern methods of treating tumors focus on specific drug delivery to the tumor site, actively targeting the tumor cells, as well as the reduction of side effects. One of the most promising current approaches is based on oncolytic viruses. Antitumor properties of viruses were documented at the beginning of the 20th century when some cancer patients recovered after acute viral infections, particularly influenza [4]. Vaccinia virus (VACV) is a member of the Poxviridae family, has natural antitumor properties, and provides a good basis for generating efficient recombinant oncolytic strains. Furthermore, VACV has never been shown to integrate into the host genome [5]. VACV is likely one of the safest and well-studied viruses due to extensive research being done in molecular biology and pathophysiology to investigate its potential as a vaccine for smallpox eradication programs. It has been administered to over 200 million people worldwide. VACV antitumor therapeutic effectiveness has been established in xenograft models with a variety of tumor types for human and canine cancers. Furthermore, recombinant oncolytic VACVs expressing genes encoding light-emitting proteins are a big improvement in a treatment strategy that combines tumor-specific therapies and diagnostics. Oncolytic virus treatments are effective in xenograft cancer models in mice, however, the significant improvements found in mice do not always translate to human cancer patients. These therapies should be tested in dogs with spontaneous cancer not only to offer well translatable information regarding the possible efficiency of viral therapy for human cancers but also to improve the health of our household pets as well. Spontaneous canine tumors are starting to be regarded as an essential model of human cancers that can reproduce the tumor microenvironment and immune response of cancer patients [6]. Just as data obtained in dog experiments can improve cancer therapy for human patients, these findings can also be used to improve treatment protocols in canine patients. Hundreds of studies and dozens of reviews have been published regarding the antitumor effects of various recombinants of VACV, but information on the anticancer features of initial, genetically-unmodified "na{\"i}ve" VACV is still limited. In the first studies, we compared different wild-type, non-modified strains of VACV and tested their oncolytic properties on a panel of various cancer cells derived from different organs. In addition, we also tested a protection system based on the "Trojan horse" concept - using a combination of human Adipose tissue-derived Stem Cells (hADSC) and three different wild-type single plaque purified Vaccinia virus strains: W1, L1, and T1. We showed that all tested human cell lines (FaDu, MDA MB 231, HNT-13, HNT-35, and PC-3) are permissive to L0, W0, T0, L1, W1, and L1 infection. Furthermore, we tested the cytotoxicity of VACV in different cancer cell lines (A549, PC-3, MDA-MB 231, FaDu, HNT-13, HNT-25, and HNT-35). All strains lysed the cells, which was most visible at 96 hpi. We also showed that all tested strains could efficiently infect and multiply in hADSC at a high level. In our in vivo study, we tested the therapeutic efficacy of the wild-type Vaccinia viruses L1, W1, and T1 alone or in combination with hADSC. Wild-type VACV strains were tested for their oncolytic efficiency in human lung adenocarcinoma (A549) in a xenograft model. Treatment of A549 tumors with different doses of L1 and W1 as well as with a L1/ADSC or W1/ADSC combination led to significant tumor regression compared to the PBS control. Additionally, the treatment with L1 and W1 and the combination of L1/ADSC and W1/ADSC was well tolerated by the animals. In the case of the wild-type Tian Tan strain, results were not obtained due to the high cytotoxicity of this strain. Therefore, it should be attenuated for further studies. In the second part of the current study, we investigated the oncolytic effect of C1-opt1, W1 opt1, and L3-opt1 strains based on the wild-type Copenhagen, Wyeth, and Lister vaccines with additional expression of turboFP635. Replication and cytotoxicity assays demonstrated that all 3 viruses were able to infect, replicate in and kill canine tumor cell lines STSA-1 and CT1258 in a virus dose- and time- dependent fashion. Cytotoxicity and replication assays were also performed on cultured canine Adipose-derived Mesenchymal Stem Cells (cAdMSC). The results showed that the cells were lysed much slower than the tumor cells. It suggests that these cells can harbour the virus for a long-term period, allowing the virus to spread into the body and there is enough time to reach the primary tumor or metastases before the cell carrier is destroyed. The viral replication in cAdMSC in our study was lower than in canine cancer cells (STSA-1 and CT1258) at the same MOI. After being studied in cell culture, C1 opt1 and their combination with cAdMSC (C1-opt1/cAdMSC) were used in canine STSA 1 tumor bearing nude mice. We tested the oncolytic effect of the C1-opt1 virus alone and in combination with cAdMSC in the canine STSA-1 xenograft mouse model. Altogether, our findings have shown that both C1-opt1 and cAdMSC/C1-opt1 significantly reduced tumor size or eliminated the tumor. There was no significant difference between C1-opt1 alone and cAdMSC/C1-opt1. The virus particles were mostly found within the tumor after 24 dpi, some amount of virus particles were found in the lungs of mice injected with a combination of cAdMSC/C1-opt1 but not in the group injected with virus alone (cAdMSC might get stuck in the lungs and cause virus propagation there). Taken together, this study provided a proof-of-concept that hADSC/cAdMSC can be used as a carrier system for the "Trojan horse" concept. However, it should be confirmed in another experimental model system, such as canine patients. Moreover, these findings suggest that wild-type, non-modified strains of Vaccinia virus isolates can be considered promising candidates for oncolytic virotherapy, especially in combination with mesenchymal stem cells.}, subject = {ADSC}, language = {en} } @phdthesis{Ye2022, author = {Ye, Mingyu}, title = {Immunotherapy with Vaccinia virus co-expressing tumor-associated antigens and mouse IL-2 cytokine in mice with mammary cancer}, doi = {10.25972/OPUS-25309}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-253095}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Interleukin 2 (IL-2) was the first cytokine applied for cancer treatment in human history. It has been approved as monotherapy for renal cell carcinoma and melanoma by the FDA and does mediate the regression of the tumors in patients. One of the possible mechanisms is that the administration of IL-2 led to T lymphocytes expansion, including CD4+ and CD8+ T cells. In addition, a recent study demonstrated that antigen-specific T cells could also be expanded through the induction of IL-2, which plays a crucial role in mediating tumor regression. However, despite the long-term and extensive use of IL-2 in the clinic, the ratio of patients who get a complete response was still low, and only about one-fifth of patients showed objective tumor regression. Therefore, the function of IL-2 in cancer treatment should continue to be optimized and investigated. A study by Franz O. Smith et al. has shown that the combination treatment of IL-2 and tumor-associated antigen vaccine has a strong trend to increased objective responses compared to patients with melanoma receiving IL-2 alone. Peptide vaccines are anti-cancer vaccines able to induce a powerful tumor antigenspecific immune response capable of eradicating the tumors. According to the type of antigens, peptide vaccines can be classified into two distinct categories: Tumor-associated antigens (TAA) vaccine and tumor-specific neoantigens (TSA) vaccine. Currently, Peptide vaccines are mainly investigated in phase I and phase II clinical trials of human cancer patients with various advanced cancers such as lung cancer, gastrointestinal tumors, and breast cancers. Vaccinia virus (VACV) is one of the safest viral vectors, which has been wildly used in cancer treatment and pathogen prevention. As an oncolytic vector, VACV can carry multiple large foreign genes, which enable the virus to introduce diagnostic and therapeutic agents without dramatically reducing the viral replication. Meanwhile, the recombinant vaccinia virus (rVACV) can be easily generated by homologous recombination. Here, we used the vaccinia virus as the therapeutic cancer vector, expressing mouse Interleukin 2 (IL-2) and tumor-associated antigens simultaneously to investigate the combined effect of anti-tumor immune response in the 4T1 mouse tumor model. As expected, the VACV driven mIL-2 expression remarkably increased both CD4+ and CD8+ populations in vivo, and the virus-expressed tumor-associated peptides successfully elicited theantigen-specific T cell response to inhibit the growth of tumors. Furthermore, the experiments with tumor-bearing animals showed that the mIL-2 plus tumor antigens expressing VACV vector gave a better anti-cancer response than the mIL-2 alone expressing vector. The combinations did significantly more inhibit tumor growth than mIL-2 treatment alone. Moreover, the results confirmed our previous unpublished data that the mIL-2 expression driven by synthetic early/late promoter in the Lister strain VACV could enhance the tumor regression in the 4T1 mouse model.}, language = {en} } @article{HendricksMuellerFassnachtetal.2022, author = {Hendricks, Anne and M{\"u}ller, Sophie and Fassnacht, Martin and Germer, Christoph-Thomas and Wiegering, Verena A. and Wiegering, Armin and Reibetanz, Joachim}, title = {Impact of lymphadenectomy on the oncologic outcome of patients with adrenocortical carcinoma — a systematic review and meta-analysis}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {2}, issn = {2072-6694}, doi = {10.3390/cancers14020291}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254798}, year = {2022}, abstract = {(1) Background: Locoregional lymphadenectomy (LND) in adrenocortical carcinoma (ACC) may impact oncological outcome, but the findings from individual studies are conflicting. The aim of this systematic review and meta-analysis was to determine the oncological value of LND in ACC by summarizing the available literature. (2) Methods: A systematic search on studies published until December 2020 was performed according to the PRISMA statement. The primary outcome was the impact of lymphadenectomy on overall survival (OS). Two separate meta-analyses were performed for studies including patients with localized ACC (stage I-III) and those including all tumor stages (I-IV). Secondary endpoints included postoperative mortality and length of hospital stay (LOS). (3) Results: 11 publications were identified for inclusion. All studies were retrospective studies, published between 2001-2020, and 5 were included in the meta-analysis. Three studies (N = 807 patients) reported the impact of LND on disease-specific survival in patients with stage I-III ACC and revealed a survival benefit of LND (hazard ratio (HR) = 0.42, 95\% confidence interval (95\% CI): 0.26-0.68). Based on results of studies including patients with ACC stage I-IV (2 studies, N = 3934 patients), LND was not associated with a survival benefit (HR = 1.00, 95\% CI: 0.70-1.42). None of the included studies showed an association between LND and postoperative mortality or LOS. (4) Conclusion: Locoregional lymphadenectomy seems to offer an oncologic benefit in patients undergoing curative-intended surgery for localized ACC (stage I-III).}, language = {en} } @phdthesis{Ku2022, author = {Ku, Hsing-Ping}, title = {Cadherin-13 Deficiency Impacts Murine Serotonergic Circuitries and Cognitive Functions}, doi = {10.25972/OPUS-25144}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251446}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Cadherin-13 (CDH13) is a member of the cadherin superfamily that lacks the typical transmembrane domain for classical cadherins and is instead attached to the cell membrane with a GPI-anchor. Over the years, numerous genome-wide association (GWA) studies have identified CDH13 as a risk factor for neurodevelopmental disorders, including attention- deficit/hyperactivity disorder (ADHD) and autism spectrum disorder. Further evidence using cultured cells and animal models has shown that CDH13 plays important roles in cell migration, neurite outgrowth and synaptic function of the central nervous system. Research in our laboratory demonstrated that the CDH13 deficiency resulted in increased cell density of serotonergic neurons of the dorsal raphe (DR) in developing and mature mouse brains as well as serotonergic hyperinnervation in the developing prefrontal cortex, one of the target areas of DR serotonergic neurons. In this study, the role of CDH13 was further explored using constitutive and serotonergic system-specific CDH13-deficient mouse models. Within the adult DR structure, the increased density of DR serotonergic neurons was found to be topographically restricted to the ventral and lateral-wing, but not dorsal, clusters of DR. Furthermore, serotonergic hyperinnervation was observed in the target region of DR serotonergic projection neurons in the lateral wings. Unexpectedly, these alterations were not observed in postnatal day 14 brains of CDH13-deficient mice. Additionally, behavioral assessments revealed cognitive deficits in terms of compromised learning and memory ability as well as impulsive-like behaviors in CDH13-deficient mice, indicating that the absence of CDH13 in the serotonergic system alone was sufficient to impact cognitive functions and behavioral competency. Lastly, in order to examine the organization of serotonergic circuitries systematically and to tackle limitations of conventional immunofluorescence, a pipeline of the whole-mount immunostaining in combination with the iDISCO+ based rapid tissue clearing techniques was established. This will facilitate future research of brain neurotransmitter systems at circuitry and/or whole-brain levels and provide an excellent alternative for visualizing detailed and comprehensive information about a biological system in its original space. In summary, this study provided new evidence of CDH13's contribution to proper brain development and cognitive function in mice, thereby offering insights into further advancement of therapeutic approaches for neurodevelopmental disorders.}, language = {en} } @phdthesis{Bangalore2022, author = {Bangalore, Disha Mohan}, title = {Mechanistic studies of protein-DNA interactions by single molecule atomic force microscopy}, doi = {10.25972/OPUS-25204}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252047}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Protein-DNA interactions are central to many biological processes and form the bedrock of gene transcription, DNA replication, and DNA repair processes. Many proteins recognize specific sequences in DNA- a restriction enzyme must only cut at the correct sequence and a transcription factor should bind at its consensus sequence. Some proteins are designed to bind to specific structural or chemical features in DNA, such as DNA repair proteins and some DNA modifying enzymes. Target-specific DNA binding proteins initially bind to non-specific DNA and then search for their target sites through different types of diffusion mechanisms. Atomic force microscopy (AFM) is a single-molecule technique that is specifically well-suited to resolve the distinct states of target-specific as well as nonspecific protein-DNA interactions that are vital for a deeper insight into the target site search mechanisms of these enzymes. In this thesis, protein systems involved in epigenetic regulation, base excision repair (BER), and transcription are investigated by single-molecule AFM analyses complemented by biochemical and biophysical experiments. The first chapter of this thesis narrates the establishment of a novel, user-unbiased MatLab-based tool for automated DNA bend angle measurements on AFM data. This tool has then been employed to study the initial lesion detection step of several DNA glycosylases. These results promoted a model describing the altered plasticities of DNA at the target lesions of DNA glycosylases as the fundamental mechanism for their enhanced efficiency of lesion detection. In the second chapter of this thesis, the novel automated tool has been further extended to provide protein binding positions on the DNA along with corresponding DNA bend angles and applied to the study of DNMT3A DNA methyltransferase. These AFM studies revealed preferential co-methylation at specific, defined distances between two CpG sites by the enzyme and when combined with biochemical analyses and structural modelling supported novel modes of CpG co-methylation by DNMT3A. In the third chapter of this thesis, the role of 8-oxo-guanine glycosylase (hOGG1) in Myc-mediated transcription initiation has been investigated. AFM analyses revealed that in the presence of oxidative damage in DNA, Myc is recruited to its target site (E-box) by hOGG1 through direct protein-protein interactions, specifically under oxidizing conditions. Intriguingly, oxidation of hOGG1 was further observed to result in dimerization of hOGG1, which may also play a role in the mechanism of transcription regulation by hOGG1 under oxidative stress.}, subject = {Transcription}, language = {en} } @phdthesis{Dietz2022, author = {Dietz, Christopher Andreas}, title = {Distinguishing phenotypes of Complex Regional Pain Syndrome}, doi = {10.25972/OPUS-25632}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256327}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This work investigated phenotypes of complex regional pain syndrome (CRPS) with special interest in sensory abnormalities. Quantitative sensory testing (QST) was used to assess sensory function. In addition, clinical and sensory differences of fracture and CRPS patients were addressed. Finally, the longitudinal outcome of CRPS patients was part of this thesis.}, language = {en} } @phdthesis{Dietzsch2022, author = {Dietzsch, Julia}, title = {Nucleic acid-mediated fluorescence activation and chromophore assembly}, doi = {10.25972/OPUS-25976}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259761}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Nucleic acids are not only one of the most important classes of macromolecules in biochemistry but also a promising platform for the defined arrangement of chromophores. Thanks to their precise organization by directional polar and hydrophobic interactions, oligonucleotides can be exploited as suitable templates for multichromophore assemblies with predictable properties. To expand the toolbox of emissive, base pairing nucleobase analogs several barbituric acid merocyanine (BAM) chromophores with tunable spectroscopic properties were synthesized and incorporated into RNA, DNA and glycol nucleic acid (GNA) oligonucleotides. A multitude of duplexes containing up to ten BAM chromophores was obtained and analysis by spectroscopic methods revealed the presence of dipolarly coupled merocyanine aggregates with properties strongly dependent on the chromophore orientation toward each other and the backbone conformation. These characteristics were exploited for various applications such as FRET pair formation and polymerase chain reaction (PCR) experiments. The observed formation of higher-order aggregates implies future applications of these new oligonucleotide-chromophore systems as light-harvesting DNA nanomaterials. Besides oligonucleotide templated covalent assembly of chromophores also non-covalent nucleic acid-chromophore complexes are a broad field of research. Among these, fluorogenic RNA aptamers are of special interest with the most versatile ones based on derivatives of the GFP chromophore hydroxybenzylidene imidazolone (HBI). Therefore, new HBI-derived chromophores with an expanded conjugated system and an additional exocyclic amino group for an enhanced binding affinity were synthesized and analyzed in complex with the Chili aptamer. Among these, structurally new fluorogenes with strong fluorescence activation upon binding to Chili were identified which are promising for further derivatization and application as color-switching sensor devices for example.}, subject = {Nucleins{\"a}uren}, language = {en} } @article{AdemmerHornQuast2022, author = {Ademmer, Martin and Horn, Wolfram and Quast, Josefine}, title = {Stock market dynamics and the relative importance of domestic, foreign, and common shocks}, series = {International Journal of Finance \& Economics}, volume = {27}, journal = {International Journal of Finance \& Economics}, number = {4}, doi = {10.1002/ijfe.2194}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225729}, pages = {3911 -- 3923}, year = {2022}, abstract = {We quantify the contemporaneous relationships among stock markets in the euro area, the United States, and a group of emerging economies over the period from 2008 to 2017. Exploiting the heteroskedasticity in the stock market data, we identify shocks that originated in the respective domestic markets and shocks that are common to all markets. Our results underline the leading role of the United States in international equity markets, but also point to the importance of indirect spillovers for all economies. Variance decompositions show that while domestic shocks explain the bigger part of the variation in each stock market, a substantial part of the variation in the euro area and the emerging economies can be attributed to foreign shocks. A comparison with a sample covering the pre-crisis period from 1999 to 2007 suggests a strengthening of the linkages among global stock markets in recent years. In particular, the spillovers from advanced to emerging economies have become more pronounced.}, language = {en} } @phdthesis{Gross2022, author = {Gross, Carina}, title = {The role of platelets in hepatic ischemia reperfusion injury in mice}, doi = {10.25972/OPUS-21618}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216180}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Platelets are the second most abundant blood cells and their main function is maintenance of vascular integrity. In addition, platelets are increasingly recognized as cells with immune functions, as they participate in the recruitment of immune cells and modulate the progression and severity of an immune response. So-called lipid mediators, which are - besides other cells - released by activated platelets, influence the immune response. LTB4 is one of these potent lipid mediators and is able to activate neutrophils and induce their infiltration into injured tissue. In order to investigate the involvement of platelets in inflammatory processes, a murine model of hepatic ischemia reperfusion injury as well as confocal intravital microscopy of the liver were established. Both methods were used to analyze the influence of platelets on the inflammation that follows sterile liver inflammation. We found platelet function to be unaltered after three hours of reperfusion and platelet aggregation to be irrelevant for the outcome of hepatic ischemia reperfusion injury. However, a strong impact of the GPIb-vWF axis could be observed, as antibody mediated blockade of GPIb as well as vWF-deficiency significantly reduced liver damage markers and decreased neutrophil infiltration. GPIb-IL-4R mice were used to exclude the possibility that the protective effects of the anti-GPIbα antibody treatment (p0p/B) results from something else than blocking GPIbα. Furthermore, the slope of neutrophil infiltration was decreased in p0p/B-treated mice, leading to overall decreased neutrophil numbers in the liver after three hours of reperfusion. Blockade of the integrin αIIbβ3, however, showed no reduction in neutrophil infiltration into the post-ischemic liver, in line with unaltered liver damage. To study the role of leukotriene B4, conditional and constitutive knockout mice for the LTA4 hydrolase, which catalyzes the last step in LTB4 synthesis, were generated. Lta4h deficiency did not affect general platelet functionality in hemostasis and thrombosis. Interestingly, Lta4h-/- mice were not protected from cellular damage following hepatic ischemia, despite lower neutrophil numbers in the post-ischemic liver. Intravital microscopy of the pancreas was established and revealed increased CD4+ T cell numbers in GPVI-deficient animals compared to WT controls in line with the pre-diabetic phenotype of Gp6-/- mice that was revealed in Grzegorz Sumara's group. Furthermore, platelet 'behavior' in pancreatic islets was observed following glucose injection. We found a high number of platelets adherent to islet sinusoids under basal conditions and no rolling/decelerating of platelets following glucose injection. This was accompanied by temporary sinusoidal constriction and stop of the blood flow. This phenomenon was not observed in control settings (injection of PBS, insulin or L-glucose). In a side project, which was carried out jointly with Tobias Heib, a side by side comparison of the classical syringe-based flushing and the centrifugation-based spinning method to isolate murine bone marrow was conducted. Flow cytometry revealed no differences in the distribution of hematopoietic stem cells and immune cells and functional analysis with primary and cultured megakaryocytes (MKs) showed comparable results in all conducted assays. Thus, our data demonstrated that the faster and more efficient spinning method can be used for the isolation of bone marrow cells.}, language = {en} } @phdthesis{Goettler2022, author = {G{\"o}ttler, David Johannes}, title = {Smoking cessation patterns in patients with established coronary heart disease}, doi = {10.25972/OPUS-22395}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223955}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Background Tobacco smoking is accountable for more than one in ten deaths in patients with cardiovascular disease. Thus, smoking cessation has a high priority in secondary prevention of coronary heart disease (CHD). The present study meant to assess smoking cessation patterns, identify parameters associated with smoking cessation and investigate personal reasons to change or maintain smoking habits in patients with established CHD. Methods Quality of CHD care was surveyed in 24 European countries in 2012/13 by the fourth European Survey of Cardiovascular Disease Prevention and Diabetes. Patients 18 to 79 years of age at the date of the CHD index event hospitalized due to first or recurrent diagnosis of coronary artery bypass graft, percutaneous coronary intervention, acute myocardial infarction or acute myocardial ischemia without infarction (troponin negative) were included. Smoking status and clinical parameters were iteratively obtained a) at the cardiovascular disease index event by medical record abstraction, b) during a face-to-face interview 6 to 36 months after the index event (i.e. baseline visit) and c) by telephone-based follow-up interview two years after the baseline visit. Parameters associated with smoking status at the time of follow-up interview were identified by logistic regression analysis. Personal reasons to change or maintain smoking habits were assessed in a qualitative interview and analyzed by qualitative content analysis. Results One hundred and four of 469 (22.2\%) participants had been classified current smokers at the index event and were available for follow-up interview. After a median observation period of 3.5 years (quartiles 3.0, 4.1), 65 of 104 participants (62.5\%) were classified quitters at the time of follow-up interview. There was a tendency of diabetes being more prevalent in quitters vs non-quitters (37.5\% vs 20.5\%, p=0.07). Higher education level (15.4\% vs 33.3\%, p=0.03) and depressed mood (17.2\% vs 35.9\%, p=0.03) were less frequent in quitters vs non-quitters. Quitters more frequently participated in cardiac rehabilitation programs (83.1\% vs 48.7\%, p<0.001). Cardiac rehabilitation appeared as factor associated with smoking cessation in multivariable logistic regression analysis (OR 5.19, 95\%CI 1.87 to 14.46, p=0.002). Persistent smokers at telephone-based follow-up interview reported on addiction as wells as relaxation and pleasure as reasons to continue their habit. Those current and former smokers who relapsed at least once after a quitting attempt, stated future health hazards as their main reason to undertake quitting attempts. Prevalent factors leading to relapse were influence by their social network and stress. Successful quitters at follow-up interview referred to smoking-related harm done to their health having had been their major reason to quit. Interpretation Participating in a cardiac rehabilitation program was strongly associated with smoking cessation after a cardiovascular disease index event. Smoking cessation counseling and relapse prophylaxis may include alternatives for the pleasant aspects of smoking and incorporate effective strategies to resist relapse.}, subject = {Tabakkonsum}, language = {en} } @misc{ReitemeyerWeinmann2022, author = {Reitemeyer, Malte and Weinmann, Felix}, title = {Detection of UAP with a Nano Satellite}, doi = {10.25972/OPUS-26139}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261391}, pages = {36}, year = {2022}, abstract = {Continued reports over the past decades of unknown aerial phenomena (short UAP) have given high relevance to the investigation and research of these. Especially reports by US Navy pilots and official investigations by the US Office of the director of national intelligence have emphasized the value of such efforts. Due to the inherently limited scope of earth based observations, a satellite based instrument for detection of such phenomena may prove especially useful. This paper as such investigates the possible viability of such an instrument on a nano satellite mission.}, subject = {Satellit}, language = {en} } @phdthesis{Jarzina2022, author = {Jarzina, Sebastian Oskar}, title = {Assessment of systemic toxicity in vitro using the Adverse Outcome Pathway (AOP) concept: nephrotoxicity due to receptor-mediated endocytosis and lysosomal overload and inhibition of mtDNA polymerase-ɣ as case studies}, doi = {10.25972/OPUS-26484}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264842}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The US National Research Council (NRC) report "Toxicity Testing in the 21st Century: A Vision and a strategy (Tox21)", published in 2007, calls for a complete paradigm shift in tox-icity testing. A central aspect of the proposed strategy includes the transition from apical end-points in in vivo studies to more mechanistically based in vitro tests. To support and facilitate the transition and paradigm shift in toxicity testing, the Adverse Outcome Pathway (AOP) concept is widely recognized as a pragmatic tool. As case studies, the AOP concept was ap-plied in this work to develop AOPs for proximal tubule injuries initiated by Receptor-mediated endocytosis and lysosomal overload and Inhibition of mtDNA polymerase-. These AOPs were used as a mechanistic basis for the development of in vitro assays for each key event (KE). To experimentally support the developed in vitro assays, proximal tubule cells from rat (NRK-52E) and human (RPTEC/TERT1) were treated with model compounds. To measure the dis-turbance of lysosomal function in the AOP - Receptor-mediated endocytosis and lysosomal overload, polymyxin antibiotics (polymyxin B, colistin, polymyxin B nonapeptide) were used as model compounds. Altered expression of lysosomal associated membrane protein 1/2 (LAMP-1/2) (KE1) and cathepsin D release from lysosomes (KE2) were determined by im-munofluorescence, while cytotoxicity (KE3) was measured using the CellTiter-Glo® cell via-bility assay. Importantly, significant differences in polymyxin uptake and susceptibility be-tween cell lines were observed, underlining the importance of in vitro biokinetics to determine an appropriate in vitro point of departure (PoD) for risk assessment. Compared to the in vivo situation, distinct expression of relevant transporters such as megalin and cubilin on mRNA and protein level in the used cell lines (RPTEC/TERT1 and NRK-52E) could not be con-firmed, making integration of quantitative in vitro to in vivo extrapolations (QIVIVE) neces-sary. Integration of QIVIVE by project partners of the University of Utrecht showed an im-provement in the modelled biokinetic data for polymyxin B. To assess the first key event, (KE1) Depletion of mitochondrial DNA, in the AOP - Inhibition of mtDNA polymerase-, a RT-qPCR method was used to determine the mtDNA copy number in cells treated with mod-el compounds (adefovir, cidofovir, tenofovir, adefovir dipivoxil, tenofovir disoproxil fumarate). Mitochondrial toxicity (KE2) was measured by project partners using the high-content imaging technique and MitoTracker® whereas cytotoxicity (KE3) was determined by CellTiter-Glo® cell viability assay. In contrast to the mechanistic hypothesis underlying the AOP - Inhibition of mtDNA polymerase-, treatment with model compounds for 24 h resulted in an increase rather than a decrease in mtDNA copy number (KE1). Only minor effects on mitochondrial toxicity (KE2) and cytotoxicity (KE3) were observed. Treatment of RPT-EC/TERT1 cells for 14 days showed only a slight decrease in mtDNA copy number after treatment with adefovir dipivoxil and tenofovir disoproxil fumarate, underscoring some of the limitations of short-term in vitro systems. To obtain a first estimation for risk assessment based on in vitro data, potential points of departure (PoD) for each KE were calculated from the obtained in vitro data. The most common PoDs were calculated such as the effect concentra-tion at which 10 \% or 20_\% effect was measured (EC10, EC20), the highest no observed effect concentration (NOEC), the lowest observed effect concentration (LOEC), the benchmark 10 \% (lower / upper) concentrations (BMC10, BMCL10, BMCU10) and a modelled non-toxic con-centration (NtC). These PoDs were then compared with serum and tissue concentrations de-termined from in vivo studies after treatment with therapeutic / supratherapeutic doses of the respective drugs in order to obtain a first estimate of risk based on in vitro data. In addition, AOPs were used to test whether the quantitative key event relationships between key events allow prediction of downstream effects and effects on the adverse outcome (AO) based on measurements of an early key event. Predictions of cytotoxicity from the mathematical rela-tionships showed good concordance with measured cytotoxicity after treatment with colistin and polymyxin b nonapeptide. The work also revealed uncertainties and limitations of the ap-plied strategy, which have a significant impact on the prediction and on a risk assessment based on in vitro results.}, language = {en} } @phdthesis{Schmitt2022, author = {Schmitt, Matthias}, title = {High Energy Spin- and Momentum-Resolved Photoelectron Spectroscopy of Complex Oxides}, doi = {10.25972/OPUS-26475}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Spin- and \(k\)-resolved hard X-ray photoelectron spectroscopy (HAXPES) is a powerful tool to probe bulk electronic properties of complex metal oxides. Due to the low efficiency of common spin detectors of about \(10^{-4}\), such experiments have been rarely performed within the hard X-ray regime since the notoriously low photoionization cross sections further lower the performance tremendously. This thesis is about a new type of spin detector, which employs an imaging spin-filter with multichannel electron recording. This increases the efficiency by a factor of \(10^4\) and makes spin- and \(k\)-resolved photoemission at high excitation energies possible. Two different technical approaches were pursued in this thesis: One using a hemispherical deflection analyzer (HDA) and a separate external spin detector chamber, the other one resorting to a momentum- or \(k\)-space microscope with time-of-flight (TOF) energy recording and an integrated spin-filter crystal. The latter exhibits significantly higher count rates and - since it was designed for this purpose from scratch - the integrated spin-filter option found out to be more viable than the subsequent upgrade of an existing setup with an HDA. This instrumental development is followed by the investigation of the complex metal oxides (CMOs) KTaO\(_3\) by angle-resolved HAXPES (HARPES) and Fe\(_3\)O\(_4\) by spin-resolved HAXPES (spin-HAXPES), respectively. KTaO\(_3\) (KTO) is a band insulator with a valence-electron configuration of Ta 5\(d^0\). By angle- and spin-integrated HAXPES it is shown that at the buried interface of LaAlO\(_3\)/KTO - by the generation of oxygen vacancies and hence effective electron doping - a conducting electron system forms in KTO. Further investigations using the momentum-resolution of the \(k\)-space TOF microscope show that these states are confined to the surface in KTO and intensity is only obtained from the center or the Gamma-point of each Brillouin zone (BZ). These BZs are furthermore square-like arranged reflecting the three-dimensional cubic crystal structure of KTO. However, from a comparison to calculations it is found that the band structure deviates from that of electron-doped bulk KTaO\(_3\) due to the confinement to the interface. There is broad consensus that Fe\(_3\)O\(_4\) is a promising material for spintronics applications due to its high degree of spin polarization at the Fermi level. However, previous attempts to measure the spin polarization by spin-resolved photoemission spectroscopy have been hampered by the use of low photon energies resulting in high surface sensitivity. The surfaces of magnetite, though, tend to reconstruct due to their polar nature, and thus their magnetic and electronic properties may strongly deviate from each other and from the bulk, dependent on their orientation and specific preparation. In this work, the intrinsic bulk spin polarization of magnetite at the Fermi level (\(E_F\)) by spin-resolved photoelectron spectroscopy, is determined by spin-HAXPES on (111)-oriented thin films, epitaxially grown on ZnO(0001) to be \(P(E_F) = -80^{+10}_{-20}\) \%.}, subject = {Elektronenkorrelation}, language = {en} } @article{GuggenbergerBleyVogtetal.2022, author = {Guggenberger, Konstanze V. and Bley, Thorsten A. and Vogt, Marius L. and Urbach, Horst and Meckel, Stephan}, title = {High-Resolution Black Blood Vessel Wall Imaging in COVID-19 Encephalopathy-Is it Really Endotheliitis?}, series = {Clinical Neuroradiology}, volume = {32}, journal = {Clinical Neuroradiology}, number = {1}, doi = {10.1007/s00062-021-01109-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264794}, pages = {295-296}, year = {2022}, abstract = {No abstract available.}, language = {en} } @article{VogtKollikowskiWeidneretal.2022, author = {Vogt, Marius L. and Kollikowski, Alexander M. and Weidner, Franziska and Strinitz, Marc and Feick, J{\"o}rn and Essig, Fabian and Neugebauer, Herrmann and Haeusler, Karl Georg and Pham, Mirko and Maerz, Alexander}, title = {Safety and Effectiveness of the New Generation APERIO® Hybrid Stent-retriever Device in Large Vessel Occlusion Stroke}, series = {Clinical Neuroradiology}, volume = {32}, journal = {Clinical Neuroradiology}, number = {1}, doi = {10.1007/s00062-021-01122-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264817}, pages = {141-151}, year = {2022}, abstract = {Background It is unknown whether technological advancement of stent-retriever devices influences typical observational indicators of safety or effectiveness. Methods Observational retrospective study of APERIO® (AP) vs. new generation APERIO® Hybrid (APH) (Acandis®, Pforzheim, Germany) stent-retriever device (01/2019-09/2020) for mechanical thrombectomy (MT) in large vessel occlusion (LVO) stroke. Primary effectiveness endpoint was successful recanalization eTICI (expanded Thrombolysis In Cerebral Ischemia) ≥ 2b67, primary safety endpoint was occurrence of hemorrhagic complications after MT. Secondary outcome measures were time from groin puncture to first pass and successful reperfusion, and the total number of passes needed to achieve the final recanalization result. Results A total of 298 patients with LVO stroke who were treated by MT matched the inclusion criteria: 148 patients (49.7\%) treated with AP vs. 150 patients (50.3\%) treated with new generation APH. Successful recanalization was not statistically different between both groups: 75.7\% for AP vs. 79.3\% for APH; p = 0.450. Postinterventional hemorrhagic complications and particularly subarachnoid hemorrhage as the entity possibly associated with stent-retriever device type was significantly less frequent in the group treated with the APH: 29.7\% for AP and 16.0\% for APH; p = 0.005; however, rates of symptomatic hemorrhage with clinical deterioration and in domo mortality were not statistically different. Neither the median number of stent-retriever passages needed to achieve final recanalization, time from groin puncture to first pass, time from groin puncture to final recanalization nor the number of cases in which successful recanalization could only be achieved by using a different stent-retriever as bail-out device differed between both groups. Conclusion In the specific example of the APERIO® stent-retriever device, we observed that further technological developments of the new generation device were not associated with disadvantages with respect to typical observational indicators of safety or effectiveness.}, language = {en} } @phdthesis{Muenstermann2022, author = {M{\"u}nstermann, Marcel}, title = {The roles of the anaphylatoxin receptors during invasive disease as well as mucosal colonization caused by \(Neisseria\) \(meningitidis\)}, doi = {10.25972/OPUS-26975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269759}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The human specific gram-negative bacterium Neisseria meningitidis (Nme, meningococci) is a common colonizer of the upper respiratory tract. Upon becoming invasive, Nme can cause meningitis and life-threatening sepsis. The most important immune defense mechanism in invasive meningococcal disease (IMD) is the complement mediated killing of bacteria. The complement cascade is activated through different pathogen associated patterns and finally leads to the lysis of the bacteria by the membrane attack complex. In addition to the direct bacterial killing, the complement system is also an important player in different inflammatory processes. A hallmark of IMD is an overreaction of the immune system and the release of the potent anaphylatoxins C3a and C5a by the complement system is an important factor hereby. There are three anaphylatoxin receptors (ATRs), the C3aR, the C5aR1 and the C5aR2, capable of detecting these anaphylatoxins. It has already been shown that blocking the ATR C5aR1 strongly benefitted the outcome of IMD in a murine sepsis model. However, the roles of ATRs C3aR and C5aR2 in IMD are still unclear. This work aims to analyze the role of these ATRs in meningococcal sepsis and to identify possible underlying mechanisms. Furthermore, a possible involvement of the complement system, the ATRs and the type II CRISPR/Cas system on nasopharyngeal colonization is analyzed. In vivo depletion experiments showed that without neutrophils or monocytes/macrophages the complement system alone was not able to clear a low dose Nme infection, which highlights the importance of cellular components in IMD. Analyzing the role of the ATRs in knock-out mice with high dose Nme infections, revealed that the lack of C5aR2, like the lack of C5aR1, was beneficial for the outcome of meningococcal induced sepsis. In contrast, the lack of C3aR in knock-out mice was detrimental. The positive outcome associated with the C5aRs could be reproduced by using an antagonist against both C5aRs or an antagonist specifically against C5aR1 in WT mice. These findings are giving hope to future therapeutic applications. Next, a possible contribution of neutrophils to this positive outcome was analyzed. Absence of C5aR1 led to a decrease of degranulation by neutrophils in a murine whole blood model, while the other ATRs showed no effect. Neutrophil analysis in human whole blood, on the other hand, revealed a reduced oxidative burst and IL-8 secretion upon inhibition of all three ATRs. A functional difference between the C5aRs and the C3aR in neutrophils was observed in phagocytosis, which was reduced upon C3aR inhibition, but was unaltered with C5aR1 or C5aR2 inhibition. Possible underlying mechanisms in the phosphorylation of ERK1/2 were analyzed in bone marrow derived macrophages isolated from ATR knock-out mice. The later phosphorylation of ERK1/2 in macrophages without C5aR1 or C5aR2 expression might explain, why blocking the C5aRs is beneficial for the outcome of IMD in mice. In contrast to these findings, the colonization of the nasopharynx in huCEACAM 1 expressing mice by Nme did not seem to depend on the Complement system factors C3 and C5 nor the ATRs. Additionally, no difference in the colonization could be observed in this model using Nme mutants lacking different parts of the type 2 CRISPR/Cas system. Conclusively, this work highlights the importance of the complement system, the ATRs and the cellular components in IMD. Contrariwise, these factors did not play a role in the analyzed nasopharyngeal infection model. The beneficial effects of C5aR1 and C5aR2 lack/inhibition in IMD might have medicinal applications, which could support the standard therapies of IMD in the future.}, subject = {Anaphylatoxine}, language = {en} } @article{KlementPoppKauletal.2022, author = {Klement, Rainer J. and Popp, Ilinca and Kaul, David and Ehret, Felix and Grosu, Anca L. and Polat, B{\"u}lent and Sweeney, Reinhart A. and Lewitzki, Victor}, title = {Accelerated hyper-versus normofractionated radiochemotherapy with temozolomide in patients with glioblastoma: a multicenter retrospective analysis}, series = {Journal of Neuro-Oncology}, volume = {156}, journal = {Journal of Neuro-Oncology}, number = {2}, issn = {1573-7373}, doi = {10.1007/s11060-021-03926-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269806}, pages = {407-417}, year = {2022}, abstract = {Background and Purpose The standard treatment of glioblastoma patients consists of surgery followed by normofractionated radiotherapy (NFRT) with concomitant and adjuvant temozolomide chemotherapy. Whether accelerated hyperfractionated radiotherapy (HFRT) yields comparable results to NFRT in combination with temozolomide has only sparsely been investigated. The objective of this study was to compare NFRT with HFRT in a multicenter analysis. Materials and Methods A total of 484 glioblastoma patients from four centers were retrospectively pooled and analyzed. Three-hundred-ten and 174 patients had been treated with NFRT (30 × 1.8 Gy or 30 × 2 Gy) and HFRT (37 × 1.6 Gy or 30 × 1.8 Gy twice/day), respectively. The primary outcome of interest was overall survival (OS) which was correlated with patient-, tumor- and treatment-related variables via univariable and multivariable Cox frailty models. For multivariable modeling, missing covariates were imputed using multiple imputation by chained equations, and a sensitivity analysis was performed on the complete-cases-only dataset. Results After a median follow-up of 15.7 months (range 0.8-88.6 months), median OS was 16.9 months (15.0-18.7 months) in the NFRT group and 14.9 months (13.2-17.3 months) in the HFRT group (p = 0.26). In multivariable frailty regression, better performance status, gross-total versus not gross-total resection, MGMT hypermethylation, IDH mutation, smaller planning target volume and salvage therapy were significantly associated with longer OS (all p < 0.01). Treatment differences (HFRT versus NFRT) had no significant effect on OS in either univariable or multivariable analysis. Conclusions Since HFRT with temozolomide was not associated with worse OS, we assume HFRT to be a potential option for patients wishing to shorten their treatment time.}, language = {en} } @phdthesis{Schmitt2022, author = {Schmitt, Nadine J. B.}, title = {What is integrity and how do we use it? - Enhancing the validity of integrity by reviewing integrity tests, expanding the nomological network, and reducing faking}, doi = {10.25972/OPUS-26046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260468}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This dissertation focuses on the construct and criterion validity of integrity tests and aims to enhance both. To accomplish this goal, three approaches were adopted: First, an overview and systematic comparison of integrity tests was conducted with reference to the construction and application of the tests. Second, the nomological network of integrity tests was expanded with reference to honesty-humility and organizational citizenship behavior at their factor and facet level. Third, two promising methods to reduce faking on integrity tests were tested: the double rating method (Hui, 2001) and the indirect questioning technique. In line with previous research, the results of the overview and comparison of integrity measures confirmed that integrity tests are multidimensional and heterogenous. A clear definition of integrity is urgently needed. The personality trait of honesty-humility and its facets of fairness, and modesty revealed the most significant relationships to integrity. Moreover, organizational citizenship behavior and its facets of altruism, conscientiousness, and sportsmanship were found to significantly relate to integrity. Furthermore, integrity tests were able not only to predict organizational citizenship behavior but also to incrementally predict job performance and organizational citizenship behavior beyond the factor and facet level of the personality traits of conscientiousness and honesty-humility. In contrast to the indirect questioning technique, the double rating method, which includes an other rating and a self rating, was shown to be able to significantly reduce faking on integrity tests in an anonymous survey setting. This dissertation makes an important contribution to better explain the construct and nomological network of integrity, provide a more detailed view on integrity tests and their protection against faking, and expand the predictive and incremental validity of these tests. The implications for future research and practice are further discussed.}, subject = {Integrit{\"a}t}, language = {en} } @article{KittelSchneiderFeliceBuhagiaretal.2022, author = {Kittel-Schneider, Sarah and Felice, Ethel and Buhagiar, Rachel and Lambregtse-van den Berg, Mijke and Wilson, Claire A. and Banjac Baljak, Visnja and Vujovic, Katarina Savic and Medic, Branislava and Opankovic, Ana and Fonseca, Ana and Lupattelli, Angela}, title = {Treatment of peripartum depression with antidepressants and other psychotropic medications: a synthesis of clinical practice guidelines in Europe}, series = {International Journal of Environmental Research and Public Health}, volume = {19}, journal = {International Journal of Environmental Research and Public Health}, number = {4}, issn = {1660-4601}, doi = {10.3390/ijerph19041973}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262130}, year = {2022}, abstract = {This study examined (1) the availability and content of national CPGs for treatment of peripartum depression, including comorbid anxiety, with antidepressants and other psychotropics across Europe and (2) antidepressant and other psychotropic utilization data as an indicator of prescribers' compliance to the guidelines. We conducted a search using Medline and the Guidelines International Network database, combined with direct e-mail contact with national Riseup-PPD COST ACTION members and researchers within psychiatry. Of the 48 European countries examined, we screened 41 records and included 14 of them for full-text evaluation. After exclusion of ineligible and duplicate records, we included 12 CPGs. Multiple CPGs recommend antidepressant initiation or continuation based on maternal disease severity, non-response to first-line non-pharmacological interventions, and after risk-benefit assessment. Advice on treatment of comorbid anxiety is largely missing or unspecific. Antidepressant dispensing data suggest general prescribers' compliance with the preferred substances of the CPG, although country-specific differences were noted. To conclude, there is an urgent need for harmonized, up-to-date CPGs for pharmacological management of peripartum depression and comorbid anxiety in Europe. The recommendations need to be informed by the latest available evidence so that healthcare providers and women can make informed, evidence-based decisions about treatment choices.}, language = {en} } @article{Rudert2022, author = {Rudert, Maximilian}, title = {Taking the next step in personalised orthopaedic implantation}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {3}, issn = {2075-4426}, doi = {10.3390/jpm12030365}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262089}, year = {2022}, abstract = {No abstract available}, language = {en} } @phdthesis{Meininger2022, author = {Meininger, Markus}, title = {Calcium hydroxide as antibacterial implant coating}, doi = {10.25972/OPUS-26112}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261122}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In modern medicine hip and knee joint replacement are common surgical procedures. However, about 11 \% of hip implants and about 7 \% of knee implants need re-operations. The comparison of implant registers revealed two major indications for re-operations: aseptic loosening and implant infections, that both severely impact the patients' health and are an economic burden for the health care system. To address these problems, a calcium hydroxide coating on titanium was investigated in this thesis. Calcium hydroxide is a well-known antibacterial agent and used with success in dentistry. The coatings were applied with electrochemically assisted deposition, a versatile tool that combines easiness of process with the ability to coat complex geometries homogeneously. The pH-gradient during coating was investigated and showed the surface confinement of the coating process. Surface pre-treatment altered the surface morphology and chemistry of the titanium substrates and was shown to affect the morphology of the calcium hydroxide coatings. The influence of the coating parameters stirring speed and current pulsing were examined in various configurations and combinations and could also affect the surface morphology. A change in surface morphology results in a changed adhesion and behavior of cells and bacteria. Thus, the parameters surface pre-treatment, stirring speed and current pulsing presented a toolset for tailoring cellular response and antibacterial properties. Microbiological tests with S. aureus and S. epidermidis were performed to test the time-dependent antibacterial activity of the calcium hydroxide coatings. A reduction of both strains could be achieved for 13 h, which makes calcium hydroxide a promising antibacterial coating. To give insight into biofilm growth, a protocol for biofilm staining was investigated on titanium disks with S. aureus and S. epidermidis. Biofilm growth could be detected after 5 days of bacterial incubation, which was much earlier than the 3 weeks that are currently assumed in medical treatment. Thus, it should be considered to treat infections as if a biofilm were present from day 5 on. The ephemeral antibacterial properties of calcium hydroxide were further enhanced and prolonged with the addition of silver and copper ions. Both ionic modifications significantly enhanced the bactericidal potential. The copper modification showed higher antibacterial effects than the silver modification and had a higher cytocompatibility which was comparable to the pure calcium hydroxide coating. Thus, copper ions are an auspicious option to enhance the antibacterial properties. Calcium hydroxide coatings presented in this thesis have promising antibacterial properties and can easily be applied to complex geometries, thus they are a step in fighting aseptic loosening and implant infections.}, subject = {Calciumhydroxid}, language = {en} } @phdthesis{Gaal2022, author = {Gaal, Chiara Claudia}, title = {Cardiac Antigens and T cell Specificity after Experimental Myocardial Infarction in Mice}, doi = {10.25972/OPUS-26004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260047}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Cardiovascular diseases (CVD), subsuming atherosclerosis of the coronary arteries and subsequent myocardial infarction, are the leading cause of death in the European Union (over 4 million deaths annually), with devastating individual and economic consequences. Recent studies revealed that T cells play a crucial role in post-MI inflammation, healing and remodelling processes. Nevertheless, the specificity profile of adaptive immune responses in the infarcted myocardium has not yet been differentiated. The experiments portrayed in this thesis sought to assess whether post-MI CD4+ T cell responses in mice are triggered by heart specific antigens, and eventually identify relevant epitopes. We were able to create a murine antigen atlas including a list of 206 epitopes for I-Ab and 193 epitopes for I-Ad presented on MHC-II in the context of MI. We sought to consecutively test this panel by in vitro T cell proliferation and antigen recall assays ex vivo. The elispot assay was used as a readout for antigen-specific stimulation by measurement of IL-2 and IFN-γ production, currently the most sensitive approach available to detect even small counts of antigen producing cells. Splenocytes as well as lymphocytes from mediastinal lymph nodes were purified from animals 7 days or 56 days after EMI conducted by ligation of the left anterior descending artery. We were able to provide evidence that post-MI T cell responses in Balb/c mice are triggered by heart-specific antigens and that MYHCA, especially MYHCA614-628, is relevant for that response. Moreover, a significant specific T cell response after MI in C57BL/6J mice was observed for α actin, cardiac muscle 1 [ACTC1], myosin-binding protein C3 [MYBPC3] and myosin heavy chain α [MYHCA] derived heart specific antigens. Generally, the epitopes of interest for Balb/c as well as C57BL/6J could be further investigated and may eventually be modulated in the future.}, subject = {Regulatorische T-Lymphozyt}, language = {en} } @article{PrezzaRyanMaedleretal.2022, author = {Prezza, Gianluca and Ryan, Daniel and M{\"a}dler, Gohar and Reichardt, Sarah and Barquist, Lars and Westermann, Alexander J.}, title = {Comparative genomics provides structural and functional insights into Bacteroides RNA biology}, series = {Molecular Microbiology}, volume = {117}, journal = {Molecular Microbiology}, number = {1}, doi = {10.1111/mmi.14793}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259594}, pages = {67-85}, year = {2022}, abstract = {Bacteria employ noncoding RNA molecules for a wide range of biological processes, including scaffolding large molecular complexes, catalyzing chemical reactions, defending against phages, and controlling gene expression. Secondary structures, binding partners, and molecular mechanisms have been determined for numerous small noncoding RNAs (sRNAs) in model aerobic bacteria. However, technical hurdles have largely prevented analogous analyses in the anaerobic gut microbiota. While experimental techniques are being developed to investigate the sRNAs of gut commensals, computational tools and comparative genomics can provide immediate functional insight. Here, using Bacteroides thetaiotaomicron as a representative microbiota member, we illustrate how comparative genomics improves our understanding of RNA biology in an understudied gut bacterium. We investigate putative RNA-binding proteins and predict a Bacteroides cold-shock protein homolog to have an RNA-related function. We apply an in silico protocol incorporating both sequence and structural analysis to determine the consensus structures and conservation of nine Bacteroides noncoding RNA families. Using structure probing, we validate and refine these predictions and deposit them in the Rfam database. Through synteny analyses, we illustrate how genomic coconservation can serve as a predictor of sRNA function. Altogether, this work showcases the power of RNA informatics for investigating the RNA biology of anaerobic microbiota members.}, language = {en} } @article{BahenaDaftarianMaroofianetal.2022, author = {Bahena, Paulina and Daftarian, Narsis and Maroofian, Reza and Linares, Paola and Villalobos, Daniel and Mirrahimi, Mehraban and Rad, Aboulfazl and Doll, Julia and Hofrichter, Michaela A. H. and Koparir, Asuman and R{\"o}der, Tabea and Han, Seungbin and Sabbaghi, Hamideh and Ahmadieh, Hamid and Behboudi, Hassan and Villanueva-Mendoza, Cristina and Cort{\´e}s-Gonzalez, Vianney and Zamora-Ortiz, Rocio and Kohl, Susanne and Kuehlewein, Laura and Darvish, Hossein and Alehabib, Elham and La Arenas-Sordo, Maria de Luz and Suri, Fatemeh and Vona, Barbara and Haaf, Thomas}, title = {Unraveling the genetic complexities of combined retinal dystrophy and hearing impairment}, series = {Human Genetics}, volume = {141}, journal = {Human Genetics}, number = {3-4}, issn = {1432-1203}, doi = {10.1007/s00439-021-02303-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267750}, pages = {785-803}, year = {2022}, abstract = {Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf-blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75\%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15\%) probands displayed other genetic entities with dual sensory impairment, including Alstr{\"o}m syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf-blind cohort was 92\%. Two (3\%) probands were partially solved and only 3 (5\%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.}, language = {en} } @phdthesis{Slyschak2022, author = {Slyschak, Anna}, title = {Fear conditioning, its generalization and extinction in children and adolescents under consideration of trait anxiety and anxiety sensitivity}, doi = {10.25972/OPUS-26780}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267806}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The propounded thesis investigated fear learning including fear conditioning, its generalization as well as its extinction in 133 healthy children and adolescents aged 8 to 17 years. The main goal was to analyze these processes also in the course of childhood and adolescence due to far less research in this age span compared to adults. Of note, childhood is the typical period for the onset of anxiety disorders. To achieve this, an aversive discriminative fear conditioning, generalization and extinction paradigm, which based on the "screaming lady paradigm" from Lau et al. (2008) and was adapted by Schiele \& Reinhard et al. (2016), was applied. All probands traversed the pre-acquisition (4 x CS-, 4 x CS+, no US), the acquisition (12 x CS-, 12 x CS+, reinforcement rate: 83\%), the generalization (12 x CS-, 12 x GS4, 12 x GS3, 12 x GS2, 12 x GS1, 12 x CS+, reinforcement rate: 50\%) and the extinction (18 x CS-, 18 x CS+, no US). The generalization stimuli, i.e. GS1-GS4, were built out of CS- and CS+ in different mixtures on a percentage basis in steps of 20\% from CS- to CS+. Pictures of faces of two actresses with a neutral expression were used for the discriminative conditioning, whereby the CS+ was paired with a 95-dB loud female scream at the same time together with a fearful facial expression (US). CS- and GS1-GS4 were never followed by the US. Subjective ratings (arousal, valence and US expectancy) were collected and further the psychophysiological measure of the skin conductance response (SCR). The hypotheses were 1) that underage probands show a negative correlation between age and overgeneralization and 2) that anxiety is positively correlated with overgeneralization in the same sample. ANOVAs with repeated measures were conducted for all four dependent variables with phase (pre-acquisition phase, 1. + 2. acquisition phase, 1. + 2. generalization phase, 1. - 3. extinction phase) and stimulus type (CS-, CS+, GS1-GS4) as within-subject factors. For the analyses of the modulatory effects of age and anxiety in additional separate ANCOVAs were conducted including a) age, b) the STAIC score for trait anxiety and c) the CASI score for anxiety sensitivity as covariates. Sex was always included as covariate of no interest. On the one hand, findings indicated that the general extent of the reactions (arousal, valence and US expectancy ratings and the SCR) decreased with growing age, i.e. the older the probands the lower their reactions towards the stimuli regardless of the type of dependent variable. On the other hand, ratings of US expectancy, i.e. the likelihood that a stimulus is followed by a US (here: female scream coupled with a fearful facial expression), showed better discrimination skills the older the probands were, resulting in a smaller overgeneralization within older probands. It must be emphasized very clearly that no causality can be derived. Thus, it was only an association revealed between 15 age and generalization of conditioned fear, which is negative. Furthermore, no obvious impact of trait anxiety could be detected on the different processes of fear learning. Especially, no overgeneralization was expressed by the probands linked to higher trait anxiety. In contrast to trait anxiety, for anxiety sensitivity there was an association between its extent and the level of fear reactions. This could be described best with a kind of parallel shifts: the higher the anxiety sensitivity, the stronger the fear reactions. Likewise, for anxiety sensitivity no overgeneralization due to a stronger extent of anxiety sensitivity could be observed. Longitudinal follow-up examinations and, furthermore, neurobiological investigations are needed for replication purposes and purposes of gaining more supporting or opposing insights, but also for the profound exploration of the impact of hormonal changes during puberty and of the maturation processes of different brain structures. Finally, the question whether enhanced generalization of conditioned fear facilitates the development of anxiety disorders or vice versa remains unsolved yet.}, subject = {Furcht}, language = {en} } @article{SvirinVeniaminovaCostaNunesetal.2022, author = {Svirin, Evgeniy and Veniaminova, Ekaterina and Costa-Nunes, Jo{\~a}o Pedro and Gorlova, Anna and Umriukhin, Aleksei and Kalueff, Allan V. and Proshin, Andrey and Anthony, Daniel C. and Nedorubov, Andrey and Tse, Anna Chung Kwan and Walitza, Susanne and Lim, Lee Wei and Lesch, Klaus-Peter and Strekalova, Tatyana}, title = {Predation stress causes excessive aggression in female mice with partial genetic inactivation of tryptophan hydroxylase-2: evidence for altered myelination-related processes}, series = {Cells}, volume = {11}, journal = {Cells}, number = {6}, issn = {2073-4409}, doi = {10.3390/cells11061036}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267250}, year = {2022}, abstract = {The interaction between brain serotonin (5-HT) deficiency and environmental adversity may predispose females to excessive aggression. Specifically, complete inactivation of the gene encoding tryptophan hydroxylase-2 (Tph2) results in the absence of neuronal 5-HT synthesis and excessive aggressiveness in both male and female null mutant (Tph2\(^{-/-}\)) mice. In heterozygous male mice (Tph2\(^{+/-}\)), there is a moderate reduction in brain 5-HT levels, and when they are exposed to stress, they exhibit increased aggression. Here, we exposed female Tph2\(^{+/-}\) mice to a five-day rat predation stress paradigm and assessed their emotionality and social interaction/aggression-like behaviors. Tph2\(^{+/-}\) females exhibited excessive aggression and increased dominant behavior. Stressed mutants displayed altered gene expression of the 5-HT receptors Htr1a and Htr2a, glycogen synthase kinase-3 β (GSK-3β), and c-fos as well as myelination-related transcripts in the prefrontal cortex: myelin basic protein (Mbp), proteolipid protein 1 (Plp1), myelin-associated glycoprotein (Mag), and myelin oligodendrocyte glycoprotein (Mog). The expression of the plasticity markers synaptophysin (Syp) and cAMP response element binding protein (Creb), but not AMPA receptor subunit A2 (GluA2), were affected by genotype. Moreover, in a separate experiment, na{\"i}ve female Tph2\(^{+/-}\) mice showed signs of enhanced stress resilience in the modified swim test with repeated swimming sessions. Taken together, the combination of a moderate reduction in brain 5-HT with environmental challenges results in behavioral changes in female mice that resemble the aggression-related behavior and resilience seen in stressed male mutants; additionally, the combination is comparable to the phenotype of null mutants lacking neuronal 5-HT. Changes in myelination-associated processes are suspected to underpin the molecular mechanisms leading to aggressive behavior.}, language = {en} } @phdthesis{Flegler2022, author = {Flegler, Vanessa Judith}, title = {Application of electron cryomicroscopy for structural and functional studies on the mechanosensitive channels of small conductance}, doi = {10.25972/OPUS-26897}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268979}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Bacteria thrive and survive in many different environments, and as a result, they have developed robust mechanisms to adapt rapidly to alterations in their surroundings. The protection against osmotic forces is provided by mechanosensitive channels: their primary function is to maintain the integrity of the cell upon a hypoosmotic shock. The mechanosensitive channel of small conductance (MscS) is not only the smallest common structural unit of a diverse family that allows for a tailored response in osmoregulation; it is also the most intensively studied homologue. Mechanosensitive channels directly sense elevated membrane tension levels generated by increased pressure within the cell and open transiently. Escherichia coli has six paralogues that differ in their gating properties and the number of additional transmembrane (TM) helices. These TM helices, termed sensor paddles, are essential for sensing, as they directly contact the surrounding membrane; however, the role of the additional TM helices is still unclear. Furthermore, lipids occupy hydrophobic pockets far away from the membrane plane. A recent gating model for MscS states that increased membrane tension triggers the expulsion of lipids out of those pockets, modulating different conformational states of MscS. This model focuses on bound lipids, but it is still unclear to what extent the direct interaction with the membrane influences sensing and how relevant it is for the larger paralogues. In the herein described work, structural studies on two larger paralogues, the medium-sized channel YnaI and the large channel YbiO were realised using electron cryomicroscopy (cryo-EM). Lipids were identified in YnaI in the pockets in a similar position and orientation as in MscS, suggesting a conserved sensing mechanism. Moreover, the copolymer diisobutylene/maleic acid (DIBMA) allowed the extraction of artificially activated YnaI from plasma membranes, leading to an open-like form of this channel. This novel conformation indicated that the pore helices bend at a GGxGG motif during gating, which is unique among the Escherichia coli paralogues, concomitant with a structural reorganisation of the sensor paddles. Thus, despite a high similarity of their closed states, the gating mechanisms of MscS and YnaI are surprisingly different. Furthermore, the comparison of MscS, YnaI, and YbiO accentuates variations and similarities between the differently sized family members, implying fine-tuning of channel properties in the pore regions and the cytosolic lateral entry sides into the channel. Structural analyses of MscS reconstituted into different systems showed the advantages and disadvantages of certain polymers and detergents. The novel DIBMA copolymer and the more conventional amphiphilic polymers, so-called Amphipols, perturb contacting transmembrane helices or lead to their denaturation. Due to this observation, the obtained structures of YnaI must also be cautiously considered. The structures obtained in detergents resulted in unaffected channels; however, the applicability of detergents for MscS-like channels is limited by the increased required sample concentration. The role of lipids for gating MscS in the absence of a membrane was examined by deliberately removing coordinated lipid molecules from MscS using different amounts and kinds of detergent. The effects on the channel were inspected by cryo-EM. These experiments showed that closed MscS adopts the open conformation when it is enough delipidated by incubation with the detergent n-dodecyl-β-D-maltoside, and adding lipids to the open channel reverses this process. The results agree with the state-of-the-art model that the amount of lipid molecules in the pockets and grooves is responsible for the conformational state of MscS. Furthermore, incubation with the detergent lauryl maltose neopentyl glycol, which has stabilising and delipidating characteristics, resulted in a high-resolution structure of open MscS exhibiting an intricate network of ligands. Based on this structure, an updated gating model is proposed, which states that upon opening, lipids from the pockets migrate into the cytosolic membrane leaflet, while lipids from the periplasmic leaflet enter the grooves that arise between the sensor paddles.}, language = {en} } @article{SuratMeyerSautterRueschetal.2022, author = {Surat, G{\"u}zin and Meyer-Sautter, Pascal and R{\"u}sch, Jan and Braun-Feldweg, Johannes and Markus, Christian Karl and Germer, Christoph-Thomas and Lock, Johan Friso}, title = {Cefazolin might be adequate for perioperative antibiotic prophylaxis in intra-abdominal infections without sepsis: a quality improvement study}, series = {Antibiotics}, volume = {11}, journal = {Antibiotics}, number = {4}, issn = {2079-6382}, doi = {10.3390/antibiotics11040501}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270816}, year = {2022}, abstract = {Background: The adequate choice of perioperative antibiotic prophylaxis (PAP) could influence the risk of surgical site infections (SSIs) in general surgery. A new local PAP guideline was implemented in May 2017 and set the first-generation cefazolin (CFZ) instead the second-generation cefuroxime (CXM) as the new standard prophylactic antibiotic. The aim of this study was to compare the risk of SSIs after this implementation in intra-abdominal infections (IAIs) without sepsis. Methods: We performed a single center-quality improvement study at a 1500 bed sized university hospital in Germany analyzing patients after emergency surgery during 2016 to 2019 (n = 985), of which patients receiving CXM or CFZ were selected (n = 587). Propensity score matching was performed to ensure a comparable risk of SSIs in both groups. None-inferiority margin for SSIs was defined as 8\% vs. 4\%. Results: Two matched cohorts with respectively 196 patients were compared. The rate of SSIs was higher in the CFZ group (7.1\% vs. 3.6\%, p = 0.117) below the non-inferiority margin. The rate of other postoperative infections was significantly higher in the CFZ group (2.0\% vs. 8.7\%, p = 0.004). No other differences including postoperative morbidity, mortality or length-of-stay were observed. Conclusion: Perioperative antibiotic prophylaxis might be safely maintained by CFZ even in the treatment of intra-abdominal infections.}, language = {en} } @phdthesis{Barth2022, author = {Barth, Dominik}, title = {Computation of multi-branch-point covers and applications in Galois theory}, doi = {10.25972/OPUS-27702}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-277025}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {We present a technique for computing multi-branch-point covers with prescribed ramification and demonstrate the applicability of our method in relatively large degrees by computing several families of polynomials with symplectic and linear Galois groups. As a first application, we present polynomials over \(\mathbb{Q}(\alpha,t)\) for the primitive rank-3 groups \(PSp_4(3)\) and \(PSp_4(3).C_2\) of degree 27 and for the 2-transitive group \(PSp_6(2)\) in its actions on 28 and 36 points, respectively. Moreover, the degree-28 polynomial for \(PSp_6(2)\) admits infinitely many totally real specializations. Next, we present the first (to the best of our knowledge) explicit polynomials for the 2-transitive linear groups \(PSL_4(3)\) and \(PGL_4(3)\) of degree 40, and the imprimitive group \(Aut(PGL_4(3))\) of degree 80. Additionally, we negatively answer a question by K{\"o}nig whether there exists a degree-63 rational function with rational coefficients and monodromy group \(PSL_6(2)\) ramified over at least four points. This is achieved due to the explicit computation of the corresponding hyperelliptic genus-3 Hurwitz curve parameterizing this family, followed by a search for rational points on it. As a byproduct of our calculations we obtain the first explicit \(Aut(PSL_6(2))\)-realizations over \(\mathbb{Q}(t)\). At last, we present a technique by Elkies for bounding the transitivity degree of Galois groups. This provides an alternative way to verify the Galois groups from the previous chapters and also yields a proof that the monodromy group of a degree-276 cover computed by Monien is isomorphic to the sporadic 2-transitive Conway group \(Co_3\).}, subject = {Galois-Theorie}, language = {en} } @article{DufnerKesslerJustetal.2022, author = {Dufner, Vera and Kessler, Almuth Friederike and Just, Larissa and Hau, Peter and Bumes, Elisabeth and Pels, Hendrik Johannes and Grauer, Oliver Martin and Wiese, Bettina and L{\"o}hr, Mario and Jordan, Karin and Strik, Herwig}, title = {The emesis trial: depressive glioma patients are more affected by chemotherapy-induced nausea and vomiting}, series = {Frontiers in Neurology}, volume = {13}, journal = {Frontiers in Neurology}, issn = {1664-2295}, doi = {10.3389/fneur.2022.773265}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262859}, year = {2022}, abstract = {Purpose Glioma patients face a limited life expectancy and at the same time, they suffer from afflicting symptoms and undesired effects of tumor treatment. Apart from bone marrow suppression, standard chemotherapy with temozolomide causes nausea, emesis and loss of appetite. In this pilot study, we investigated how chemotherapy-induced nausea and vomiting (CINV) affects the patients' levels of depression and their quality of life. Methods In this prospective observational multicentre study (n = 87), nausea, emesis and loss of appetite were evaluated with an expanded MASCC questionnaire, covering 10 days during the first and the second cycle of chemotherapy. Quality of life was assessed with the EORTC QLQ-C30 and BN 20 questionnaire and levels of depression with the PHQ-9 inventory before and after the first and second cycle of chemotherapy. Results CINV affected a minor part of patients. If present, it reached its maximum at day 3 and decreased to baseline level not before day 8. Levels of depression increased significantly after the first cycle of chemotherapy, but decreased during the further course of treatment. Patients with higher levels of depression were more severely affected by CINV and showed a lower quality of life through all time-points. Conclusion We conclude that symptoms of depression should be perceived in advance and treated in order to avoid more severe side effects of tumor treatment. Additionally, in affected patients, delayed nausea was most prominent, pointing toward an activation of the NK1 receptor. We conclude that long acting antiemetics are necessary totreat temozolomide-induced nausea.}, language = {en} } @article{Gerhard‐HartmannJoehrensSchinagletal.2022, author = {Gerhard-Hartmann, Elena and J{\"o}hrens, Korinna and Schinagl, Lisa-Marie and Zam{\´o}, Alberto and Rosenwald, Andreas and Anagnostopoulos, Ioannis and Rosenfeldt, Mathias}, title = {Epstein-Barr virus infection patterns in nodular lymphocyte-predominant Hodgkin lymphoma}, series = {Histopathology}, volume = {80}, journal = {Histopathology}, number = {7}, doi = {10.1111/his.14652}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276327}, pages = {1071 -- 1080}, year = {2022}, abstract = {Aims To investigate Epstein-Barr virus (EBV) latency types in 19 cases of EBV-positive nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), as such information is currently incomplete. Methods and results Immunohistochemistry (IHC) for CD20, CD79a, PAX5, OCT2, CD30, CD15, CD3 and programmed cell death protein 1 was performed. For EBV detection, in-situ hybridisation (ISH) for EBV-encoded RNA (EBER) was employed combined with IHC for EBV-encoded latent membrane protein (LMP)-1, EBV-encoded nuclear antigen (EBNA)-2, and EBV-encoded BZLF1. In 95\% of the cases, neoplastic cells with features of Hodgkin and Reed-Sternberg (HRS) cells were present, mostly showing expression of CD30. In all cases, the B-cell phenotype was largely intact, and delineation from classic Hodgkin lymphoma (CHL) was further supported by myocyte enhancer factor 2B (MEF2B) detection. All tumour cells were EBER-positive except in two cases. EBV latency type II was most frequent (89\%) and type I was rare. Cases with latency type I were CD30-negative. Five cases contained some BZLF1-positive and/or EBNA-2-positive bystander lymphocytes. Conclusions As HRS morphology of neoplastic cells and CD30 expression are frequent features of EBV-positive NLPHL, preservation of the B-cell transcription programme, MEF2B expression combined with NLPHL-typical architecture and background composition facilitate distinction from CHL. EBER ISH is the method of choice to identify these cases. The majority present with EBV latency type II, and only rare cases present with latency type I, which can be associated with missing CD30 expression. The presence of occasional bystander lymphocytes expressing BZLF1 and/or EBNA-2 and the partial EBV infection of neoplastic cells in some cases could indicate that EBV is either not primarily involved or is only a transient driver in the pathogenesis of EBV-positive NLPHL.}, language = {en} } @phdthesis{Kaiser2022, author = {Kaiser, Dustin}, title = {Non-standard computational approaches applied to molecular systems}, doi = {10.25972/OPUS-27664}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276641}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In this thesis, several contributions to the understanding and modeling of chemical phenomena using computational approaches are presented. These investigations are characterized by the usage of non-standard computational modeling techniques, which is necessitated by the complex nature of the electronic structure or atomic fluctuations of the target molecules. Multiple biradical-type molecules and their spectroscopic properties were modeled. In the course of the investigation, it is found that especially the impact of correct molecular geometries on the computationally predicted absorption properties may be critical. In order to find the correct minimum geometries, Multi-Reference methods may have to be invoked. The impact of geometry relaxation on the excitonic properties of Perylene Bisimide dimers were investigated. Oftentimes, these geometry factors are neglected in Organic Semiconductor modeling as an approximation. This present investigation suggests that this approximation is not always valid, as certain regimes are identified where geometrical parameters have critical impact on the localization and energetic properties of excitons. The mechanism of the Triazolinedione (TAD) tyrosine bioconjugation reaction is investigated using quantum-chemical methods. By comparison of different conceivable mechanisms and their energetic ordering, the TAD tyrosine bioconjugation is found to proceed by means of a base-mediated electrophilic aromatic substitution reaction. The kth nearest neighbor entropy estimation protocol is investigated. This estimator promises accurate entropy estimates even for flexible molecules with multiple structural minima. Our granular investigation of formal and practical properties of the estimator suggests that the uneven variance of a molecule's vibrational modes is the cause of the observed slow convergence of the estimator. A rescaling procedure to reestablish fast convergence is suggested and benchmarks are performed.}, subject = {Quantenchemie}, language = {en} } @phdthesis{Schickhardt2022, author = {Schickhardt, Irene}, title = {A Process Model for Selecting the Most Appropriate Production Site : an Application-oriented Approach for OEMs based on a Literature Analysis}, doi = {10.25972/OPUS-27665}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276652}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The global selection of production sites is a very complex task of great strategic importance for Original Equipment Manufacturers (OEMs), not only to ensure their sustained competitiveness, but also due to the sizeable long-term investment associated with a production site. With this in mind, this work develops a process model with which OEMs can select the most appropriate production site for their specific production activity in practice. Based on a literature analysis, the process model is developed by determining all necessary preparation, by defining the properties of the selection process model, providing all necessary instructions for choosing and evaluating location factors, and by laying out the procedure of the selection process model. Moreover, the selection process model includes a discussion of location factors which are possibly relevant for OEMs when selecting a production site. This discussion contains a description and, if relevant, a macroeconomic analysis of each location factor, an explanation of their relevance for constructing and operating a production site, additional information for choosing relevant location factors, and information and instructions on evaluating them in the selection process model. To be successfully applicable, the selection process model is developed based on the assumption that the production site must not be selected in isolation, but as part of the global production network and supply chain of the OEM and, additionally, to advance the OEM's related strategic goals. Furthermore, the selection process model is developed on the premise that a purely quantitative model cannot realistically solve an OEM's complex selection of a production site, that the realistic analysis of the conditions at potential production sites requires evaluating the changes of these conditions over the planning horizon of the production site and that the future development of many of these conditions can only be assessed with uncertainty.}, subject = {Produktionsstandort}, language = {en} } @phdthesis{Mahler2022, author = {Mahler, David}, title = {Surface states in the topological material HgTe}, doi = {10.25972/OPUS-25398}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-253982}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The motivation for this work has been contributing a step to the advancement of technology. A next leap in technology would be the realization of a scalable quantum computer. One potential route is via topological quantum computing. A profound understanding of topological materials is thus essential. My work contributes by the investigation of the exemplary topological material HgTe. The focus lies on the understanding of the topological surface states (TSS) and new possibilities to manipulate them appropriately. Traditionally top gate electrodes are used to adjust the carrier density in such semi-conductor materials. We found that the electric field of the top gate can further alter the properties of the HgTe layer. The formation of additional massive Volkov-Pankratov states limits the accessibility of the TSS. The understanding of these states and their interplay with the TSS is necessary to appropriately design devices and to ensure their desired properties. Similarly, I observed the existence and stability of TSSs even without a bandgap in the bulk band structure in the inversion induced Dirac semi-metal phase of compressively strained HgTe. The finding of topological surface states in inversion-induced Dirac semi-metals provides a consistent and simple explanation for the observation reported for \(\text{Cd}_3\text{As}_2\). These observations have only been possible due to the high quality of the MBE grown HgTe layers and the access of different phases of HgTe via strain engineering. As a starting point I performed Magneto-transport measurements on 67 nm thick tensilely strained HgTe layers grown on a CdTe substrate. We observed multiple transport channels in this three-dimensional topological insulator and successfully identified them. Not only do the expected topological surface states exist, but also additional massive surface states have been observed. These additional massive surface states are formed due to the electrical field applied at the top gate, which is routinely used to vary the carrier density in the HgTe layer. The additional massive surface states are called Volkov-Pankratov states after B. A. Volkov and O. A. Pankratov. They predicted the existence of similar massive surface states at the interface of materials with mutually inverted bands. We first found indications for such massive Volkov-Pankratov states in high-frequency compressibility measurements for very high electron densities in a fruitful collaboration with LPA in Paris. Magneto-transport measurements and \(k \cdot p\) calculations revealed that such Volkov-Pankratov states are also responsible for the observed whole transport. We also found indications for similar massive VPS in the electron regime, which coexist with the topological surface states. The topological surface states exist over the full investigated gate range including a regime of pure topological insulator transport. To increase the variability of the topological surface states we introduced a modulation doping layer in the buffer layer. This modulation doping layer also enabled us to separate and identify the top and bottom topological surface states. We used the variability of the bulk band structure of HgTe with strain to engineer the band structure of choice using virtual substrates. The virtual substrates enable us to grow compressively strained HgTe layers that do not possess a bandgap, but instead linear crossing points. These layers are predicted to beDirac semi-metals. Indeed I observed also topological surface states and massive Volkov-Pankratov states in the compressively strained Dirac semi-metal phase. The observation of topological surfaces states also in the Dirac semi-metal phase has two consequences: First, it highlights that no bulk bandgap is necessary to observe topological surface states. Second, the observation of TSS also in the Dirac semi-metal phase emphasizes the importance of the underlying band inversion in this phase. I could not find any clear signatures of the predicted disjoint topological surface states, which are typically called Fermi-arcs. The presence of topological surface states and massive Volkov-Pankratov states offer a simple explanation for the observed quantum Hall effect and other two-dimensional transport phenomena in the class of inversion induced Dirac semi-metals, as \(\text{Cd}_3\text{As}_2\). This emphasizes the importance of the inherent bulk band inversion of different topological materials and provides a consistent and elegant explanation for the observed phenomena in these materials. Additionally, it offers a route to design further experiments, devices, and thus the foundation for the induction of superconductivity and thus topological quantum computing. Another possible path towards quantum computing has been proposed based on the chiral anomaly. The chiral anomaly is an apparent transport anomaly that manifests itself as an additional magnetic field-driven current in three-dimensional topological semimetals with a linear crossing point in their bulk band structure. I observed the chiral anomaly in compressively strained HgTe samples and performed multiple control experiments to identify the observed reduction of the magnetoresistance with the chiral anomaly. First, the dependence of the so-called negative magnetoresistance on the angle and strength of the magnetic field has been shown to fit the expectation for the chiral anomaly. Second, extrinsic effects as scattering could be excluded as a source for the observed negative MR using samples with different mobilities and thus impurity concentrations. Third, the necessity of the linear crossing point has been shown by shifting the electrochemical potential away from the linear crossing points, which diminished the negative magnetoresistance. Fourth, I could not observe a negative magnetoresistance in the three-dimensional topological insulator phase of HgTe. These observations together prove the existence of the chiral anomaly and verify compressively strained HgTe as Dirac semi-metal. Surprisingly, the chiral anomaly is also present in unstrained HgTe samples, which constitute a semi-metal with a quadratic band touching point. This observation reveals the relevance of the Zeeman effect for the chiral anomaly due to the lifting of the spin-degeneracy in these samples. Additionally to the chiral anomaly, the Dirac semi-metal phase of compressively strained HgTe showed other interesting effects. For low magnetic fields, a strong weak-antilocalization has been observed. Such a strong weak-anti-localization correction in a three-dimensional layer is surprising and interesting. Additionally, non-trivial magnetic field strength and direction dependencies have been observed. These include a strong positive magnetoresistance for high magnetic fields, which could indicate a metal-insulator transition. On a more device-oriented note, the semi-metal phase of unstrained HgTe constitutes the lower limit of the by strain engineering adjustable minimal carrier density of the topological surface states and thus of very high mobility. To sum up, topological surface states have been observed in the three-dimensional topological insulator phase and the Dirac semi-metal phase of HgTe. The existence and accessibility of topological surface states are thus independent of the existence of a bandgap in the bulk band structure. The topological surface states can be accompanied by massive Volkov-Pankratov states. These VPS are created by electric fields, which are routinely applied to adjust the carrier density in semiconductor devices. The theoretical predicted chiral anomaly has been observed in the Dirac semi-metal phase of HgTe. In contrast to theoretical predictions, no indications for the Fermi-arc called disjoint surface states have been observed, but instead the topological and massive Volkov-Pankratov surface states have been found. These states are thus expected for all inversion-induced topological materials.}, subject = {Quecksilbertellurid}, language = {en} } @phdthesis{Bertero2022, author = {Bertero, Edoardo}, title = {Mechano-energetic uncoupling in Barth syndrome cardiomyopathy}, doi = {10.25972/OPUS-25517}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255176}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In this Doctoral Thesis we investigated the consequences of perturbed mitochondrial calcium handling in the context of a rare human disease, Barth syndrome, in which the altered phospholipid composition of the inner mitochondrial membrane affects the structural organization of several protein complexes, including the mitochondrial calcium uniporter. We discovered that loss of the mitochondrial calcium uniporter in cardiac, but not skeletal muscle mitochondria hinders the calcium-induced adaptation of mitochondrial oxidative metabolism during workload transitions. This mechano-energetic uncoupling impairs the physiological increase in contractile force during physical exercise and might predispose Barth syndrome patients to the development of arrhythmias.}, language = {en} } @article{UereyenBachoferKuenzer2022, author = {Uereyen, Soner and Bachofer, Felix and Kuenzer, Claudia}, title = {A framework for multivariate analysis of land surface dynamics and driving variables — a case study for Indo-Gangetic river basins}, series = {Remote Sensing}, volume = {14}, journal = {Remote Sensing}, number = {1}, issn = {2072-4292}, doi = {10.3390/rs14010197}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255295}, year = {2022}, abstract = {The analysis of the Earth system and interactions among its spheres is increasingly important to improve the understanding of global environmental change. In this regard, Earth observation (EO) is a valuable tool for monitoring of long term changes over the land surface and its features. Although investigations commonly study environmental change by means of a single EO-based land surface variable, a joint exploitation of multivariate land surface variables covering several spheres is still rarely performed. In this regard, we present a novel methodological framework for both, the automated processing of multisource time series to generate a unified multivariate feature space, as well as the application of statistical time series analysis techniques to quantify land surface change and driving variables. In particular, we unify multivariate time series over the last two decades including vegetation greenness, surface water area, snow cover area, and climatic, as well as hydrological variables. Furthermore, the statistical time series analyses include quantification of trends, changes in seasonality, and evaluation of drivers using the recently proposed causal discovery algorithm Peter and Clark Momentary Conditional Independence (PCMCI). We demonstrate the functionality of our methodological framework using Indo-Gangetic river basins in South Asia as a case study. The time series analyses reveal increasing trends in vegetation greenness being largely dependent on water availability, decreasing trends in snow cover area being mostly negatively coupled to temperature, and trends of surface water area to be spatially heterogeneous and linked to various driving variables. Overall, the obtained results highlight the value and suitability of this methodological framework with respect to global climate change research, enabling multivariate time series preparation, derivation of detailed information on significant trends and seasonality, as well as detection of causal links with minimal user intervention. This study is the first to use multivariate time series including several EO-based variables to analyze land surface dynamics over the last two decades using the causal discovery algorithm PCMCI.}, language = {en} } @phdthesis{Bold2022, author = {Bold, Kevin}, title = {Macrocyclic Oligothiophene Bridged Perylene Bisimide Donor-Acceptor Dyads}, doi = {10.25972/OPUS-27192}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-271926}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {A series of donor-acceptor macrocyclic architectures comprising oligothiophene strands that connect the imide positions of a perylene bisimide have been synthesized via a platinum-mediated cross-coupling strategy. The target structures were characterized by steady-state UV/Vis absorption, fluorescence and transient absorption spectroscopy, as well as cyclic and differential pulse voltammetry. Crystal structure analysis of the macrocycles revealed insights into the bridge arrangements. The properties of the macrocyclic bridges were compared to linear oligothiophene reference compounds which itself exhibited an unusual electrochemical effect.}, subject = {Perylenbisdicarboximide}, language = {en} } @phdthesis{Hahn2022, author = {Hahn, Lukas}, title = {Novel Thermoresponsive Hydrogels Based on Poly(2-oxazoline)s and Poly(2-oxazine)s and their Application in Biofabrication}, doi = {10.25972/OPUS-27129}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-271299}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In this work, the influence of aromatic structures on drug encapsulation, self-assembly and hydrogel formation was investigated. The physically crosslinked gelling systems were characterized and optimized for the use in biofabrication and applied in initial (bio)printing experiments. Chapter I: The cytocompatible (first in vitro and in vivo studies) amphiphile PMeOx-b-PBzOx-b- PMeOx (A-PBzOx-A) was used for the solubilization of PTX, schizandrin A (SchA), curcumin (CUR), niraparib and HS-173. Chapter II: Compared to the polymers A-PPheOx-A, A-PBzOx-A and A-PBzOzi-A, only the polymer A-PPheOzi-A showed a reversible temperature- and concentration-dependent inverse thermogelation, which is accompanied by a morphology change from long wormlike micelles in the gel to small spherical micelles in solution. The worm formation results from novel interactions between the hydrophilic and hydrophobic aromatic polymer blocks. Changes in the hydrophilic block significantly alter the gel system. Rheological properties can be optimized by concentration and temperature, which is why the hydrogel was used to significantly improve the printability and stability of Alg in a blend system. Chapter III: By extending the side chain of the aromatic hydrophobic block, the inverse thermogelling polymer A-poly(2-phenethyl-2-oxazoline)-A (A-PPhenEtOx-A) is obtained. Rapid gelation upon cooling is achieved by inter-correlating spherical micelles. Based on ideal rheological properties, first cytocompatible bioprinting experiments were performed in combination with Alg. The polymers A- poly(2-benzhydryl-2-oxazoline)-A (A-PBhOx-A) and A-poly(2-benzhydryl-2-oxazine) (A-PBhOzi-A) are characterized by two aromatic benzyl units per hydrophobic repeating unit. Only the polymer A- PBhOzi-A exhibited inverse thermogelling behavior. Merging micelles could be observed by electron microscopy. The system was rheologically characterized and discussed with respect to an application in 3D printing. Chapter IV: The thermogelling POx/POzi system, in particular the block copolymer PMeOx-b- PnPrOzi, was used in different applications in the field of biofabrication. The introduction of maleimide and furan units along the hydrophilic polymer part ensured additional stabilization by Diels-Alder crosslinking after the printing process.}, subject = {Polymer Science}, language = {en} } @phdthesis{Riegler2022, author = {Riegler, David}, title = {Emergent phenomena in strongly correlated electron systems: Auxiliary particle approach to the many-body problem}, doi = {10.25972/OPUS-27473}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-274737}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Emergent phenomena in condensed matter physics like, e.g., magnetism, superconductivity, or non-trivial topology often come along with a surprise and exert great fascination to researchers up to this day. Within this thesis, we are concerned with the analysis of associated types of order that arise due to strong electronic interactions and focus on the high-\(T_c\) cuprates and Kondo systems as two prime candidates. The underlying many-body problem cannot be solved analytically and has given rise to the development of various approximation techniques to tackle the problem. In concrete terms, we apply the auxiliary particle approach to investigate tight-binding Hamiltonians subject to a Hubbard interaction term to account for the screened Coulomb repulsion. Thereby, we adopt the so-called Kotliar-Ruckenstein slave-boson representation that reduces the problem to non-interacting quasiparticles within a mean-field approximation. Part I provides a pedagogical review of the theory and generalizes the established formalism to encompass Gaussian fluctuations around magnetic ground states as a crucial step to obtaining novel results. Part II addresses the two-dimensional one-band Hubbard model, which is known to approximately describe the physics of the high-\(T_c\) cuprates that feature high-temperature superconductivity and various other exotic quantum phases that are not yet fully understood. First, we provide a comprehensive slave-boson analysis of the model, including the discussion of incommensurate magnetic phases, collective modes, and a comparison to other theoretical methods that shows that our results can be massively improved through the newly implemented fluctuation corrections. Afterward, we focus on the underdoped regime and find an intertwining of spin and charge order signaled by divergences of the static charge susceptibility within the antiferromagnetic domain. There is experimental evidence for such inhomogeneous phases in various cuprate materials, which has recently aroused interest because such correlations are believed to impact the formation of Cooper pairs. Our analysis identifies two distinct charge-ordering vectors, one of which can be attributed to a Fermi-surface nesting effect and quantitatively fits experimental data in \(\mathrm{Nd}_{2-\mathrm{x}}\mathrm{Ce}_\mathrm{x}\mathrm{CuO}_4\) (NCCO), an electron-doped cuprate compound. The other resembles the so-called Yamada relation implying the formation of periodic, double-occupied domain walls with a crossover to phase separation for small dopings. Part III investigates Kondo systems by analyzing the periodic Anderson model and its generalizations. First, we consider Kondo metals and detect weakly magnetized ferromagnetic order in qualitative agreement with experimental observations, which hinders the formation of heavy fermions. Nevertheless, we suggest two different parameter regimes that could host a possible Kondo regime in the context of one or two conduction bands. The part is concluded with the study of topological order in Kondo insulators based on a three-dimensional model with centrosymmetric spin-orbit coupling. Thereby, we classify topologically distinct phases through appropriate \(\mathbb{Z}_2\) invariants and consider paramagnetic and antiferromagnetic mean-field ground states. Our model parameters are chosen to specifically describe samarium hexaboride (\(\mbox{SmB}_6\)), which is widely believed to be a topological Kondo insulator, and we identify topologically protected surface states in agreement with experimental evidence in that material. Moreover, our theory predicts the emergence of an antiferromagnetic topological insulator featuring one-dimensional hinge-states as the signature of higher-order topology in the strong coupling regime. While the nature of the true ground state is still under debate, corresponding long-range magnetic order has been observed in pressurized or alloyed \(\mbox{SmB}_6\), and recent experimental findings point towards non-trivial topology under these circumstances. The ability to understand and control topological systems brings forth promising applications in the context of spintronics and quantum computing.}, subject = {Elektronenkorrelation}, language = {en} } @article{BieniekSadeckaSzulakowskaetal.2022, author = {Bieniek, Maciej and Sadecka, Katarzyna and Szulakowska, Ludmiła and Hawrylak, Paweł}, title = {Theory of excitons in atomically thin semiconductors: tight-binding approach}, series = {Nanomaterials}, volume = {12}, journal = {Nanomaterials}, number = {9}, issn = {2079-4991}, doi = {10.3390/nano12091582}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275243}, year = {2022}, abstract = {Atomically thin semiconductors from the transition metal dichalcogenide family are materials in which the optical response is dominated by strongly bound excitonic complexes. Here, we present a theory of excitons in two-dimensional semiconductors using a tight-binding model of the electronic structure. In the first part, we review extensive literature on 2D van der Waals materials, with particular focus on their optical response from both experimental and theoretical points of view. In the second part, we discuss our ab initio calculations of the electronic structure of MoS\(_2\), representative of a wide class of materials, and review our minimal tight-binding model, which reproduces low-energy physics around the Fermi level and, at the same time, allows for the understanding of their electronic structure. Next, we describe how electron-hole pair excitations from the mean-field-level ground state are constructed. The electron-electron interactions mix the electron-hole pair excitations, resulting in excitonic wave functions and energies obtained by solving the Bethe-Salpeter equation. This is enabled by the efficient computation of the Coulomb matrix elements optimized for two-dimensional crystals. Next, we discuss non-local screening in various geometries usually used in experiments. We conclude with a discussion of the fine structure and excited excitonic spectra. In particular, we discuss the effect of band nesting on the exciton fine structure; Coulomb interactions; and the topology of the wave functions, screening and dielectric environment. Finally, we follow by adding another layer and discuss excitons in heterostructures built from two-dimensional semiconductors.}, language = {en} } @phdthesis{Becht2022, author = {Becht, Alexander Ulrich}, title = {New applications for spectroscopic and chemometric studies of drugs}, doi = {10.25972/OPUS-27534}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275342}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Spectroscopic methods were established decades ago in a wide variety of fields. This also applies to the pharmaceutical field, although they initially were mostly used for identity testing or structure elucidation only. Technical developments, such as miniaturization (NMR benchtop devices), Fourier transformations (for NMR, MIR spectroscopy) or the combination with chemometric evaluation (e.g., in Process Analytical Technology, PAT), have further increased their importance and opened up new applications. The aim of this work was to investigate further new approaches and to find new applications for already established methods and to show their benefits. By means of MIR, NIR and NMR data and their chemometric evaluation (principal component analysis, PCA; hierarchical cluster analysis, HCA; linear discriminant analysis, LDA), possibilities were presented to successfully determine the manufacturer or the pharmaceutical company of various paracetamol preparations. In the course of this, various similarities and correlations between the preparations of individual companies could also be identified. For this purpose, a suitable sample preparation was developed for each spectroscopic method, and suitable measurement parameters in order to obtain reproducible spectra for the chemometric evaluation were determined. Furthermore, the results of the two unsupervised methods (HCA, PCA) were compared with each other. The HCA was able to confirm those of the PCA for the very most part. Additionally, through these methods it was possible to characterize many of the preparations based on clusters formed by comparable tablet compositions. In order to be able to measure unmortared, whole tablets using the NIR spectrometer, an attachment was developed and manufactured using 3D printing. Its functionality was demonstrated by measuring and analyzing the tablets of two different batches of nine paracetamol preparations. The batches were clearly distinguished on the basis of a PCA and a significant difference was also demonstrated by means of statistical tests. For NMR spectroscopy, a method was developed to obtain optimized "fingerprint" spectra of drug formulations. For this purpose, a 1D DOSY measurement was elaborated, in which the signals of the active ingredient could be filtered out by the appropriate choice of measurement parameters. The chemometric evaluation can thus focus on the remaining signals of the excipients, on the basis of which the preparations of the same API can be distinguished. Especially in the case of formulations that consist largely of active ingredient, data pre processing of the spectra can thus be simplified and greater importance can be assigned to the originally very small excipient signals. A quantitative 1H NMR method was developed for the comparison of a high field spectrometer (400 MHz) with a benchtop spectrometer (80 MHz) for two finished drugs. It was shown that it is possible to obtain comparable results with both instruments, but that the influence of the excipients on the signals and the lower resolution of the benchtop instrument must be taken into account. Therefore, it was not possible to obtain comparable results without further optimization of the method for one of the active ingredients. In the investigation of various reactions between APIs and excipients using DOSY, its usefulness as a screening method in stability testing was demonstrated. For this purpose, three different APIs and excipients were stressed together and the reaction mixtures were subsequently measured using DOSY. Based on the translational diffusion coefficient, the reaction products could be identified and distinguished from the active ingredients and the excipients used. The importance of thoughtful processing could also be demonstrated. If all peak heights are selected when evaluating signals split by direct spin spin coupling, this allows the detection of hidden signals as long as not all signals have the same diffusion coefficient. The selective selection of individual peak heights in the case of split signals also enables the evaluation of signals that overlap slightly. However, the limitations of this method were also shown when two signals overlap too much and differ too little in their diffusion coefficients. Hence, it has been successfully demonstrated in the various projects that the new chemometric approaches, as well as the new applications of already established methods, enable in depth findings and thus have a clear added value.}, subject = {Instrumentelle Analytik}, language = {en} } @phdthesis{Reinhart2022, author = {Reinhart, Michael Christian}, title = {Enhancing mucosal B cell responses with all-\(trans\) retinoic acid}, doi = {10.25972/OPUS-29292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-292920}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Diarrheal diseases are a major cause of death in developing countries. Vaccinating against the causative pathogens could reduce mortality and morbidity in these countries. Unfortunately, only for some of the most common enteral pathogens are vaccines available. Some of these available vaccines have limitations in terms of effectiveness and duration of protection. There is therefore an urgent need to develop new vaccine strategies that can generate protection against enteral pathogens. The presence of all-trans retinoic acid (ATRA) during lymphocyte maturation is known to imprint a phenotype on lymphocytes that enables them to home to the intestines. Additionally, ATRA is known to play a role in B cell class switch to IgA, which is the dominant immunoglobulin in the intestines. The aim of this study was therefore to investigate whether the addition of all-trans retinoic acid (ATRA) or a retinoic acid receptor agonist (AM80) to a parenteral vaccination could provide protection at the intestinal mucosa against enteric pathogens. C57BL/6 mice received s.c. priming and boosting immunizations with Ovalbumin followed by several s.c. injections with either ATRA, AM80 or the respective solvent as control substance. Feces, serum, saliva and vaginal lavage samples were collected and analyzed by ELISA for detection and relative quantification of antigen-specific antibodies. B cell populations in the draining lymph nodes were investigated after immunization using flow-cytometry. Antigen-specific antibodies producing cells were visualized in the small intestine of vaccinated animals using two-photon microscopy. Animals that were vaccinated and were exposed to AM80, and to a lesser extent ATRA exposed mice, had higher serum, fecal, saliva and vaginal lavage antigen-specific IgA titers when compared to animals that were vaccinated but did not receive ATRA/AM80. Antigen-specific IgG titers were not altered in any of the investigated tissues. In the draining lymph nodes, IgA+ and IgG+ B cells were increased after vaccination and AM80 exposure at several time points within 14 days after vaccination. Antigen-specific IgA+ cells were found in the small intestine of immunized and AM80-exposed but not control substance-exposed mice. These results suggest that the addition of ATRA or AM80 to parenteral vaccine formulations increases the abundance of antigen-specific antibodies at mucosal surfaces, and therefore have the potential to generate protective antibody titers at those mucosal surfaces.}, subject = {Impfung}, language = {en} } @phdthesis{Hochheimer2022, author = {Hochheimer, Vanessa Christine}, title = {Of cells and enzymes: How dermal fibroblasts can impact pain in Fabry Disease and Why looking at the 3D-structure of α-Galactosidase A may be worthwhile for clinical management of Fabry patients}, doi = {10.25972/OPUS-29660}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-296607}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Fabry Disease (FD) is a genetic lysosomal storage disorder based on mutations in the gene encoding α-Galactosidase A (α-GalA) leading to accumulation of globotriaosylceramide (Gb3). Missense mutations induce an amino acid exchange (AAE) in the α-GalA. Pain is a predominant symptom in FD and the pathophysiology is unclear. Skin punch biopsies were obtained from 40 adult FD patients and ten healthy controls and dermal fibroblast cultures were generated for cell culture experiments to investigate Gb3 load, gene and protein expression patterns and ion channel activity. The 3D-structure of α-GalA was downloaded into Pymol Graphics System and the AAE was depicted and located in order to investigate the correlation between the AAE location type in the α-GalA and the clinical FD phenotype. FD dermal fibroblasts showed high Gb3 load depending on treatment interval and expressed Kca1.1 channels. Activity was reduced in FD cells at baseline, but increased over-proportionately upon Gb3-cleavage by enzyme replacement therapy. Gene and protein expression of Kca1.1 was increased in FD cells. FD dermal fibroblasts showed higher gene expression of Notch1 and several cytokines. Further, it was shown that three different AAE location types can be differentiated: mutations in the active site ('active site'), those buried in the core of α-GalA ('buried') and those at another location, mostly on the protein surface ('other'). FD patients carrying active site or buried mutations showed a severe clinical phenotype with multi-organ manifestation and early disease onset. Patients with other mutations were less severely affected with oligo-organ manifestation sparing the nervous system and later disease onset. These results show that dermal fibroblasts may be involved in FD-associated pain and that stratification of FD patients carrying missense mutations by AAE location type may be an advantageous parameter that can help in the management of FD patients.}, subject = {Fabry-Krankheit}, language = {en} } @phdthesis{Shan2022, author = {Shan, Junwen}, title = {Tailoring Hyaluronic Acid and Gelatin for Bioprinting}, doi = {10.25972/OPUS-29825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298256}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In the field of biofabrication, biopolymer-based hydrogels are often used as bulk materials with defined structures or as bioinks. Despite their excellent biocompatibility, biopolymers need chemical modification to fulfill mechanical stability. In this thesis, the primary alcohol of hyaluronic acid was oxidized using TEMPO/TCC oxidation to generate aldehyde groups without ring-opening mechanism of glycol cleavage using sodium periodate. For crosslinking reaction of the aldehyde groups, adipic acid dihydrazide was used as bivalent crosslinker for Schiff Base chemistry. This hydrogel system with fast and reversible crosslinking mechanism was used successfully as bulk hydrogel for chondrogenic differentiation with human mesenchymal stem cells (hMSC). Gelatin was modified with pentenoic acid for crosslinking reaction via light controllable thiol-ene reaction, using thiolated 4-arm sPEG as multivalent crosslinker. Due to preservation of the thermo responsive property of gelatin by avoiding chain degradation during modification reaction, this gelatin-based hydrogel system was successfully processed via 3D printing with low polymer concentration. Good cell viability was achieved using hMSC in various concentrations after 3D bioprinting and chondrogenic differentiation showed promising results.}, subject = {Hydrogel}, language = {en} } @phdthesis{Scharnagl2022, author = {Scharnagl, Julian}, title = {Distributed Guidance, Navigation and Control for Satellite Formation Flying Missions}, isbn = {978-3-945459-42-3}, doi = {10.25972/OPUS-28753}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287530}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Ongoing changes in spaceflight - continuing miniaturization, declining costs of rocket launches and satellite components, and improved satellite computing and control capabilities - are advancing Satellite Formation Flying (SFF) as a research and application area. SFF enables new applications that cannot be realized (or cannot be realized at a reasonable cost) with conventional single-satellite missions. In particular, distributed Earth observation applications such as photogrammetry and tomography or distributed space telescopes require precisely placed and controlled satellites in orbit. Several enabling technologies are required for SFF, such as inter-satellite communication, precise attitude control, and in-orbit maneuverability. However, one of the most important requirements is a reliable distributed Guidance, Navigation and Control (GNC) strategy. This work addresses the issue of distributed GNC for SFF in 3D with a focus on Continuous Low-Thrust (CLT) propulsion satellites (e.g., with electric thrusters) and concentrates on circular low Earth orbits. However, the focus of this work is not only on control theory, but control is considered as part of the system engineering process of typical small satellite missions. Thus, common sensor and actuator systems are analyzed to derive their characteristics and their impacts on formation control. This serves as the basis for the design, implementation, and evaluation of the following control approaches: First, a Model Predictive Control (MPC) method with specific adaptations to SFF and its requirements and constraints; second, a distributed robust controller that combines consensus methods for distributed system control and \$H_{\infty}\$ robust control; and finally, a controller that uses plant inversion for control and combines it with a reference governor to steer the controller to the target on an optimal trajectory considering several constraints. The developed controllers are validated and compared based on extensive software simulations. Realistic 3D formation flight scenarios were taken from the Networked Pico-Satellite Distributed System Control (NetSat) cubesat formation flight mission. The three compared methods show different advantages and disadvantages in the different application scenarios. The distributed robust consensus-based controller for example lacks the ability to limit the maximum thrust, so it is not suitable for satellites with CLT. But both the MPC-based approach and the plant inversionbased controller are suitable for CLT SFF applications, while showing again distinct advantages and disadvantages in different scenarios. The scientific contribution of this work may be summarized as the creation of novel and specific control approaches for the class of CLT SFF applications, which is still lacking methods withstanding the application in real space missions, as well as the scientific evaluation and comparison of the developed methods.}, subject = {Kleinsatellit}, language = {en} } @phdthesis{Philipp2022, author = {Philipp, Michael Stephan Maria}, title = {N-Heterocyclic Carbenes and Cyclic (Alkyl)(amino)carbenes as Ligands for p-Block Element Compounds}, doi = {10.25972/OPUS-28929}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289295}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {In der vorliegenden Arbeit wird die Synthese und Reaktivit{\"a}t neuer NHC- und cAAC-stabilisierter Lewis-S{\"a}ure/Lewis-Base-Addukte von Verbindungen mit Elementen der Gruppen 14 und 15 beschrieben.}, subject = {Lewis-Addukt}, language = {en} } @phdthesis{Awadallah2022, author = {Awadallah, Abdelhaleem Aly Ahmed}, title = {The Crew of the Sun Bark in the Amduat}, doi = {10.25972/OPUS-28711}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287115}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The Amduat is one of the most important Netherworld Books which was recorded in various kinds of Ancient Egyptian sources since the beginning of the 18th dynasty, especially the walls of the royal tombs. The main theme of the Amduat is the journey of the sun god through the underworld where the solar bark and its crew is the central scene of the journey. The study focuses on finding the reasons of choosing the crew's members who manage the sun bark's journey in the Amduat. It also aims at illustrating the functions and responsibilities of each crew member. Following a historical approach, the study analyzes the Pyramid Texts and Coffin Texts as the most important documents before the New Kingdom, and proceeding to the inscriptions and writings of the monuments which contain portrayals and inscriptions of the Amduat in the New Kingdom. Furthermore, it sheds some light on the solar cycle's main features and primary aspects, and tries to scrutinize the date, meaning, and symbolisms of the Amduat and its indications in the earlier sources.}, language = {en} } @phdthesis{Wertgen2022, author = {Wertgen, Andreas Gabriel}, title = {The Role of Source Credibility in the Validation of Text Information}, doi = {10.25972/OPUS-28861}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288619}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Numerous experiments have shown that an evaluative and passive process, known as validation, accompanies activation and integration, which are fundamental processes of text comprehension. During the construction of a mental model, validation implicitly assesses the plausibility of incoming information by checking its consistency with world knowledge, prior beliefs, and contextual information (e.g., the broader discourse context). However, research on potential influences that shape validation processes has just started. One branch of research is investigating how world knowledge and contextual information contribute to integration and validation. World knowledge usually influences validation more strongly because information plausibility is the primary criterion for validation, but strong contextual information can yield influences as well. Contextual information that may be specifically relevant for routine validation is the credibility of a source providing text information. Source credibility bears a strong conceptual relationship to the validity of information. However, a dearth of research has investigated joint effects of plausibility and source credibility for routine validation. To fill this research gap, the aim of the present dissertation was to examine the role of source credibility in routine validation processes of text information. This dissertation argues that both source credibility and plausibility are considered in these processes. In particular, information plausibility is proposed as the primary criterion, but source credibility may modulate validation as an additional criterion. To this end, three studies with five self-paced reading experiments were conducted in which reading times served as an implicit indicator of validation and plausibility judgments as an explicit indicator, and the convergence or divergence between the two indicators was interpreted. The first study examined the interplay of plausibility and source credibility for the validation of world-knowledge consistent versus inconsistent text information embedded in short narratives. This highly plausible or highly implausible information was provided by a high- or low-expertise source. In Study 1, plausibility dominated validation as suggested by faster reading times and higher plausibility judgments for world-knowledge consistent information. Importantly, source credibility modulated the validation of highly implausible information but seemed to not matter for plausible information. High-credible sources increased the implausibility of highly implausible information to a greater extent compared with low-credible sources as indicated by longer reading times and lower plausibility judgments. These results diverged from recent findings from Foy et al. (2017). The second study investigated whether the modulating role of source credibility depends on the degree of implausibility of an information. Thus, Study 2 extended Study 1 by an intermediate, somewhat implausible level of plausibility (comparable to the implausible claims in Foy et al., 2017). Similar to Study 1, plausibility dominated validation as indicated by lower reading times and plausibility judgments with higher world-knowledge inconsistency. Again, source credibility had no effect on the routine validation of plausible information. However, high-credible sources mitigated the implausibility of somewhat implausible information as indicated by faster reading times and higher plausibility judgments but exacerbated the implausibility of highly implausible information as indicated by slower reading times and lower plausibility judgments. In short, Study 2 findings not only integrates the seemingly divergent results of Study 1 and Foy et al. (2017) but also provides strong support for the assumption that the degree of implausibility determines the modulating role of source credibility for validation. The third study examined the relationship of source credibility and plausibility in an ecologically valid social media setting with short Twitter messages varying in world-knowledge and text-belief consistency by trustworthy and untrustworthy sources. In sum, plausibility and to a lesser extent source credibility mattered for routine validation and explicit evaluation of text information as indicated by reading times and plausibility judgments. However, the pattern partly diverged from Study 1 and 2, possibly because the source information was more salient. In sum, the present dissertation yielded three insights. First, the findings further extends evidence for routine validation based on world-knowledge and prior beliefs. Second, the studies suggest that source credibility can modulate validation. Readers used source credibility cues for routine validation and the explicit evaluation of text information in all studies. Third, the impact of source credibility seems to depend on the degree of implausibility of information. The present findings have theoretical implications for theories of validation and text comprehension as well as practical implications for targeting threats associated with the prevalence of inaccurate information, for example, on the World Wide Web. Future research using eye-tracking methodology could further disentangle the routine and strategic underlying processes of the relationship between source credibility and plausibility.}, subject = {Textverstehen}, language = {en} } @article{NollKrauseBeuerleetal.2022, author = {Noll, Niklas and Krause, Ana-Maria and Beuerle, Florian and W{\"u}rthner, Frank}, title = {Enzyme-like water preorganization in a synthetic molecular cleft for homogeneous water oxidation catalysis}, series = {Nature Catalysis}, journal = {Nature Catalysis}, edition = {accepted version}, doi = {10.1038/s41929-022-00843-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302897}, year = {2022}, abstract = {Inspired by the proficiency of natural enzymes, mimicking of nanoenvironments for precise substrate preorganisation is a promising strategy in catalyst design. However, artificial examples of enzyme-like activation of H\(_2\)O molecules for the challenging oxidative water splitting reaction are hardly explored. Here, we introduce a mononuclear Ru(bda) complex (M1, bda: 2,2'-bipyridine-6,6'-dicarboxylate) equipped with a bipyridine-functionalized ligand to preorganize H\(_2\)O molecules in front of the metal center as in enzymatic clefts. The confined pocket of M1 accelerates chemically driven water oxidation at pH 1 by facilitating a water nucleophilic attack pathway with a remarkable turnover frequency of 140 s\(^{-1}\) that is comparable to the oxygen-evolving complex of photosystem II. Single crystal X-ray analysis of M1 under catalytic conditions allowed the observation of a 7th H\(_2\)O ligand directly coordinated to a RuIII center. Via a well-defined hydrogen-bonding network, another H\(_2\)O substrate is preorganized for the crucial O-O bond formation via nucleophilic attack.}, language = {en} } @article{ScheinerGrashoffKleindienstetal.2022, author = {Scheiner, Christin and Grashoff, Jan and Kleindienst, Nikolaus and Buerger, Arne}, title = {Mental disorders at the beginning of adolescence: Prevalence estimates in a sample aged 11-14 years}, series = {Public Health in Practice}, volume = {4}, journal = {Public Health in Practice}, doi = {10.1016/j.puhip.2022.100348}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300404}, year = {2022}, abstract = {Objectives This study aims to provide a deeper insight into mental disorders in early adolescence. We report prevalence rates (mental health problems, depressive symptoms, eating disorders, NSSI, STBs) to be used in future studies and clinical ventures. We also expected to find gender differences, with girls being be more affected than boys are. Study design 877 adolescents (M = 12.43, SD = 0.65) from seven German high schools completed a series of questionnaires assessing their mental health (SDQ, PHQ-9, SEED, DSHI-9, Paykel Suicide Scale, FAS III). Methods We calculated cut-off-based prevalence estimates for mental health issues for the whole sample and compared estimates between genders. Results 12.5\% of the sample reported general mental health problems. The estimated prevalence of depressive symptoms lay at of 11.5\%. Additionally, 12.1\% and 1.3\% of the participants displayed relevant symptoms of anorexia or bulimia nervosa, respectively. A total of 10.8\% reported engaging in non-suicidal self-injury (NSSI) at least once in their lifetime, of whom 5.6\% reported repetitive NSSI. 30.1\% of the participants described suicidal thoughts, 9.9\% suicide plans, and 3.5\% at least one suicide attempt. Girls were generally more affected than boys, except for bulimia nervosa, suicidal behavior, and partly NSSI. Conclusion Our findings corroborate the established relevance of early adolescence for the development of mental health problems and suggest that a substantial proportion of young adolescents suffer from such problems early on. Considering the ongoing COVID-19 pandemic and reported negative mental health consequences, the current findings underline the importance of preventive interventions to avoid the manifestation of mental disorders during adolescence.}, language = {en} } @article{BauerSperlichHolmbergetal.2022, author = {Bauer, Nikolai and Sperlich, Billy and Holmberg, Hans-Christer and Engel, Florian A.}, title = {Effects of High-Intensity Interval Training in School on the Physical Performance and Health of Children and Adolescents: A Systematic Review with Meta-Analysis}, series = {Sports Medicine - Open}, volume = {8}, journal = {Sports Medicine - Open}, number = {1}, issn = {2199-1170}, doi = {10.1186/s40798-022-00437-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301205}, year = {2022}, abstract = {Objectives To assess the impact of HIIT performed at school, i.e. both in connection with physical education (intra-PE) and extracurricular sports activities (extra-PE), on the physical fitness and health of children and adolescents. Methods PubMed and SPORTDiscus were searched systematically utilizing the following criteria for inclusion: (1) healthy children and adolescents (5-18 years old) of normal weight; (2) HIIT performed intra- and/or extra-PE for at least 5 days at an intensity ≥ 80\% of maximal heart rate (HR\(_{max}\)) or peak oxygen uptake (VO\(_{2peak}\)) or as Functional HIIT; (3) comparison with a control (HIIT versus alternative interventions); and (4) pre- and post-analysis of parameters related to physical fitness and health. The outcomes with HIIT and the control interventions were compared utilizing Hedges' g effect size (ES) and associated 95\% confidence intervals. Results Eleven studies involving 707 participants who performed intra-PE and 388 participants extra-PE HIIT were included. In comparison with the control interventions, intra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 5.89 ± 5.67 (range 1.88-9.90); ES number of push-ups: 6.22 (range n.a.); ES number of sit-ups: 2.66 ± 2.02 (range 1.24-4.09)), as well as ES fasting glucose levels (- 2.68 (range n.a.)) more effectively, with large effect sizes. Extra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 1.81 (range n.a.); ES number of sit-ups: 2.60 (range n.a.)) to an even greater extent, again with large effect sizes. Neither form of HIIT was more beneficial for parameters related to cardiorespiratory fitness than the control interventions. Conclusion Compared to other forms of exercise (e.g. low-to-moderate-intensity running or walking), both intra- and extra-PE HIIT result in greater improvements in neuromuscular and anaerobic performance, as well as in fasting levels of glucose in school children.}, language = {en} } @article{GramAlbertovaSchirmeretal.2022, author = {Gram, Maximilian and Albertova, P. and Schirmer, V. and Blaimer, M. and Gamer, M. and Herrmann, M. J. and Nordbeck, P. and Jakob, P. M.}, title = {Towards robust in vivo quantification of oscillating biomagnetic fields using Rotary Excitation based MRI}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-19275-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300862}, year = {2022}, abstract = {Spin-lock based functional magnetic resonance imaging (fMRI) has the potential for direct spatially-resolved detection of neuronal activity and thus may represent an important step for basic research in neuroscience. In this work, the corresponding fundamental effect of Rotary EXcitation (REX) is investigated both in simulations as well as in phantom and in vivo experiments. An empirical law for predicting optimal spin-lock pulse durations for maximum magnetic field sensitivity was found. Experimental conditions were established that allow robust detection of ultra-weak magnetic field oscillations with simultaneous compensation of static field inhomogeneities. Furthermore, this work presents a novel concept for the emulation of brain activity utilizing the built-in MRI gradient system, which allows REX sequences to be validated in vivo under controlled and reproducible conditions. Via transmission of Rotary EXcitation (tREX), we successfully detected magnetic field oscillations in the lower nano-Tesla range in brain tissue. Moreover, tREX paves the way for the quantification of biomagnetic fields.}, language = {en} } @article{MuellerSpriestersbachMinetal.2022, author = {M{\"u}ller, S. and Spriestersbach, F. and Min, C.-H. and Fornari, C. I. and Reinert, F.}, title = {Molecular beam epitaxy of TmTe thin films on SrF\(_{2}\) (111)}, series = {AIP Advances}, volume = {12}, journal = {AIP Advances}, number = {2}, doi = {10.1063/5.0083276}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300876}, year = {2022}, abstract = {The odd parity nature of 4f states characterized by strong spin-orbit coupling and electronic correlations has led to a search for novel topological phases among rare earth compounds, such as Kondo systems, heavy Fermions, and homogeneous mixed-valent materials. Our target system is thulium telluride thin films whose bandgap is expected to be tuned as a function of lattice parameter. We systematically investigate the growth conditions of TmxTey thin films on SrF\(_{2}\) (111) substrates by molecular beam epitaxy. The ratio between Te and Tm supply was precisely tuned, resulting in two different crystalline phases, which were confirmed by x-ray diffraction and x-ray photoemission spectroscopy. By investigating the crystalline quality as a function of the substrate temperature, the optimal growth conditions were identified for the desired Tm1Te1 phase. Additional low energy electron diffraction and reflective high energy electron diffraction measurements confirm the epitaxial growth of TmTe layers. X-ray reflectivity measurements demonstrate that homogeneous samples with sharp interfaces can be obtained for varied thicknesses. Our results provide a reliable guidance to prepare homogeneous high-quality TmTe thin films and thus serve as a basis for further electronic investigations.}, language = {en} } @article{LichterPaulPaulietal.2022, author = {Lichter, Katharina and Paul, Mila Marie and Pauli, Martin and Schoch, Susanne and Kollmannsberger, Philip and Stigloher, Christian and Heckmann, Manfred and Sir{\´e}n, Anna-Leena}, title = {Ultrastructural analysis of wild-type and RIM1α knockout active zones in a large cortical synapse}, series = {Cell Reports}, volume = {40}, journal = {Cell Reports}, number = {12}, doi = {10.1016/j.celrep.2022.111382}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300913}, year = {2022}, abstract = {Rab3A-interacting molecule (RIM) is crucial for fast Ca\(^{2+}\)-triggered synaptic vesicle (SV) release in presynaptic active zones (AZs). We investigated hippocampal giant mossy fiber bouton (MFB) AZ architecture in 3D using electron tomography of rapid cryo-immobilized acute brain slices in RIM1α\(^{-/-}\) and wild-type mice. In RIM1α\(^{-/-}\), AZs are larger with increased synaptic cleft widths and a 3-fold reduced number of tightly docked SVs (0-2 nm). The distance of tightly docked SVs to the AZ center is increased from 110 to 195 nm, and the width of their electron-dense material between outer SV membrane and AZ membrane is reduced. Furthermore, the SV pool in RIM1α\(^{-/-}\) is more heterogeneous. Thus, RIM1α, besides its role in tight SV docking, is crucial for synaptic architecture and vesicle pool organization in MFBs.}, language = {en} } @article{JeanclosSchloetzerHadameketal.2022, author = {Jeanclos, Elisabeth and Schl{\"o}tzer, Jan and Hadamek, Kerstin and Yuan-Chen, Natalia and Alwahsh, Mohammad and Hollmann, Robert and Fratz, Stefanie and Yesilyurt-Gerhards, Dilan and Frankenbach, Tina and Engelmann, Daria and Keller, Angelika and Kaestner, Alexandra and Schmitz, Werner and Neuenschwander, Martin and Hergenr{\"o}der, Roland and Sotriffer, Christoph and von Kries, Jens Peter and Schindelin, Hermann and Gohla, Antje}, title = {Glycolytic flux control by drugging phosphoglycolate phosphatase}, series = {Nature Communications}, volume = {13}, journal = {Nature Communications}, number = {1}, doi = {10.1038/s41467-022-34228-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300928}, year = {2022}, abstract = {Targeting the intrinsic metabolism of immune or tumor cells is a therapeutic strategy in autoimmunity, chronic inflammation or cancer. Metabolite repair enzymes may represent an alternative target class for selective metabolic inhibition, but pharmacological tools to test this concept are needed. Here, we demonstrate that phosphoglycolate phosphatase (PGP), a prototypical metabolite repair enzyme in glycolysis, is a pharmacologically actionable target. Using a combination of small molecule screening, protein crystallography, molecular dynamics simulations and NMR metabolomics, we discover and analyze a compound (CP1) that inhibits PGP with high selectivity and submicromolar potency. CP1 locks the phosphatase in a catalytically inactive conformation, dampens glycolytic flux, and phenocopies effects of cellular PGP-deficiency. This study provides key insights into effective and precise PGP targeting, at the same time validating an allosteric approach to control glycolysis that could advance discoveries of innovative therapeutic candidates.}, language = {en} } @article{SchneiderHoehneSchneideretal.2022, author = {Schneider, Sonja Jasmin Maria and H{\"o}hne, Christian and Schneider, Martin and Schmitter, Marc}, title = {Photoacoustic tomography versus cone-beam computed tomography versus micro-computed tomography: Accuracy of 3D reconstructions of human teeth}, series = {PloS One}, volume = {17}, journal = {PloS One}, number = {12}, doi = {10.1371/journal.pone.0274818}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301437}, year = {2022}, abstract = {Objectives In this in-vitro study, teeth were imaged using photoacoustic tomography (PAT), cone-beam computed tomography (CBCT), and micro-computed tomography (μ-CT). The study had aim: to identify the best wavelength for PAT images to determine the accuracy of the three imaging methods, and to determine whether PAT images of teeth can achieve acceptable reconstruction quality. Methods Nineteen human mandibular single-rooted incisors were extracted from patients with trauma or periodontitis. To determine the best wavelength for acquiring photoacoustic images, all 19 teeth were scanned in vitro with PAT, using different laser wavelengths between 680 and 960 nm. The images were analyzed using image analysis software. To assess the accuracy of PAT and compare it with the accuracy of CBCT, each tooth was also scanned in vitro using CBCT and the reference standard technique of μ-CT. Subsequently, three different three-dimensional models, one for each imaging technique, were created for each tooth. Finally, the three different three-dimensional models acquired for the same tooth were matched and analyzed regarding volume and surface. Results The highest quality tooth images were achieved using the 680 nm wavelength, which showed the best contrast ratio. The full geometry of the dental root (μ-CT compared with PAT) could be visualized with relative standard deviations of 0.12 mm for the surface and -7.33 mm3 for the volume (n = 19). The full geometry of the dental root (μ-CT compared with CBCT) could be visualized with relative standard deviations of 0.06 mm for the surface and -14.56 mm3 for the volume (n = 19). The difference between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the root surface area was not significant (p>0.06). Conclusion Images, which were acquired using PAT at 680nm showed the best contrast ration, enabling the identification of dentin, cementum and the dental pulp. No significant differences were found between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the RSA and the total volume. Thus, three-dimensional reconstructions based on in-vitro PAT are already of acceptable reconstruction quality.}, language = {en} } @article{AsterEvdokimovBraunetal.2022, author = {Aster, H-C and Evdokimov, D. and Braun, A. and {\"U}{\c{c}}eyler, N. and Sommer, C.}, title = {Analgesic Medication in Fibromyalgia Patients: A Cross-Sectional Study}, series = {Pain Research and Management}, volume = {2022}, journal = {Pain Research and Management}, doi = {10.1155/2022/1217717}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300578}, year = {2022}, abstract = {There is no approved drug for fibromyalgia syndrome (FMS) in Europe. In the German S3 guideline, amitriptyline, duloxetine, and pregabalin are recommended for temporary use. The aim of this study was to cross-sectionally investigate the current practice of medication in FMS patients in Germany. We systematically interviewed 156 patients with FMS, while they were participating in a larger study. The patients had been stratified into subgroups with and without a decrease in intraepidermal nerve fiber density. The drugs most commonly used to treat FMS pain were nonsteroidal anti-inflammatory drugs (NSAIDs) (41.0\% of all patients), metamizole (22.4\%), and amitriptyline (12.8\%). The most frequent analgesic treatment regimen was "on demand" (53.9\%), during pain attacks, while 35.1\% of the drugs were administered daily and the remaining in other regimens. Median pain relief as self-rated by the patients on a numerical rating scale (0-10) was 2 points for NSAIDS, 2 for metamizole, and 1 for amitriptyline. Drugs that were discontinued due to lack of efficacy rather than side effects were acetaminophen, flupirtine, and selective serotonin reuptake inhibitors. Reduction in pain severity was best achieved by NSAIDs and metamizole. Our hypothesis that a decrease in intraepidermal nerve fiber density might represent a neuropathic subtype of FMS, which would be associated with better effectiveness of drugs targeting neuropathic pain, could not be confirmed in this cohort. Many FMS patients take "on-demand" medication that is not in line with current guidelines. More randomized clinical trials are needed to assess drug effects in FMS subgroups.}, language = {en} } @article{FayezBruhnFeineisetal.2022, author = {Fayez, Shaimaa and Bruhn, Torsten and Feineis, Doris and Assi, Laurent Ak{\´e} and Kushwaha, Prem Prakash and Kumar, Shashank and Bringmann, Gerhard}, title = {Naphthylisoindolinone alkaloids: the first ring-contracted naphthylisoquinolines, from the tropical liana Ancistrocladus abbreviatus, with cytotoxic activity}, series = {RSC Advances}, volume = {12}, journal = {RSC Advances}, number = {45}, doi = {10.1039/d2ra05758a}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300766}, pages = {28916-28928}, year = {2022}, abstract = {The West African liana Ancistrocladus abbreviatus is a rich source of structurally most diverse naphthylisoquinoline alkaloids. From its roots, a series of four novel representatives, named ancistrobrevolines A-D (14-17) have now been isolated, displaying an unprecedented heterocyclic ring system, where the usual isoquinoline entity is replaced by a ring-contracted isoindolinone part. Their constitutions were elucidated by 1D and 2D NMR and HR-ESI-MS. The absolute configurations at the chiral axis and at the stereogenic center were assigned by using experimental and computational electronic circular dichroism (ECD) investigations and a ruthenium-mediated oxidative degradation, respectively. For the biosynthetic origin of the isoindolinones from 'normal' naphthyltetrahydroisoquinolines, a hypothetic pathway is presented. It involves oxidative decarboxylation steps leading to a ring contraction by a benzilic acid rearrangement. Ancistrobrevolines A (14) and B (15) were found to display moderate cytotoxic effects (up to 72\%) against MCF-7 breast and A549 lung cancer cells and to reduce the formation of spheroids (mammospheres) in the breast cancer cell line.}, language = {en} } @article{AchenbachHuppertzZemanetal.2022, author = {Achenbach, Leonard and Huppertz, Gunnar and Zeman, Florian and Weber, Johannes and Luig, Patrick and Rudert, Maximilian and Krutsch, Werner}, title = {Multicomponent stretching and rubber band strengthening exercises do not reduce overuse shoulder injuries: a cluster randomised controlled trial with 579 handball athletes}, series = {BMJ Open Sport \& Exercise Medicine}, volume = {8}, journal = {BMJ Open Sport \& Exercise Medicine}, number = {1}, issn = {2055-7647}, doi = {10.1136/bmjsem-2021-001270}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300770}, year = {2022}, abstract = {Objectives Handball is associated with a high risk of overuse shoulder injury. This study investigated if an injury prevention programme effectively reduces overuse injury to the throwing shoulder of handball athletes. Methods 61 men's and women's handball teams (u-19 and senior athletes) were cluster-randomised into an intervention and a control group in the 2019-2020 season. Players of the intervention group regularly carried out an injury prevention programme. Both groups documented overuse shoulder injuries via an online questionnaire every second week. The primary endpoint was the prevalence of overuse injury to the throwing shoulder. Secondary endpoints were the influence of compliance on the primary endpoint and intensity of overuse shoulder symptoms measured by a shortened, handball-specific Western Ontario Shoulder Index (WOSI). Results 31 teams (295 players) in the intervention group and 30 teams (284 players) in the control group were included for analyses. The overall questionnaire response rate was 61\%. The average prevalence of overuse shoulder injury did not significantly differ between the intervention group (n=109, 38.4\% (95\% CI 32.9\% to 44.2\%)) and the control group (n=106, 35.9\% (95\% CI 30.7\% to 41.6\%), p=0.542). Compliance with the intervention programme did not significantly affect overuse shoulder injury (p=0.893). Using generalised estimating equations for WOSI, the estimated mean for the intervention group was 44.6 points (95\% CI 42.0 to 47.1) and 47.6 points for the control group (95\% CI 44.9 to 50.3, p=0.111). Conclusions A multicomponent exercise programme using rubber bands and stretching did not significantly reduce the prevalence or symptoms of overuse throwing shoulder injury in handball athletes of both sexes. Randomised controlled study; level of evidence I.}, language = {en} } @article{HebestreitZeidlerSchippersetal.2022, author = {Hebestreit, Helge and Zeidler, Cornelia and Schippers, Christopher and de Zwaan, Martina and Deckert, J{\"u}rgen and Heuschmann, Peter and Krauth, Christian and Bullinger, Monika and Berger, Alexandra and Berneburg, Mark and Brandstetter, Lilly and Deibele, Anna and Dieris-Hirche, Jan and Graessner, Holm and G{\"u}ndel, Harald and Herpertz, Stephan and Heuft, Gereon and Lapstich, Anne-Marie and L{\"u}cke, Thomas and Maisch, Tim and Mundlos, Christine and Petermann-Meyer, Andrea and M{\"u}ller, Susanne and Ott, Stephan and Pfister, Lisa and Quitmann, Julia and Romanos, Marcel and Rutsch, Frank and Schaubert, Kristina and Schubert, Katharina and Schulz, J{\"o}rg B. and Schweiger, Susann and T{\"u}scher, Oliver and Ungeth{\"u}m, Kathrin and Wagner, Thomas O. F. and Haas, Kirsten}, title = {Dual guidance structure for evaluation of patients with unclear diagnosis in centers for rare diseases (ZSE-DUO): study protocol for a controlled multi-center cohort study}, series = {Orphanet Journal of Rare Diseases}, volume = {17}, journal = {Orphanet Journal of Rare Diseases}, number = {1}, doi = {10.1186/s13023-022-02176-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300440}, year = {2022}, abstract = {Background In individuals suffering from a rare disease the diagnostic process and the confirmation of a final diagnosis often extends over many years. Factors contributing to delayed diagnosis include health care professionals' limited knowledge of rare diseases and frequent (co-)occurrence of mental disorders that may complicate and delay the diagnostic process. The ZSE-DUO study aims to assess the benefits of a combination of a physician focusing on somatic aspects with a mental health expert working side by side as a tandem in the diagnostic process. Study design This multi-center, prospective controlled study has a two-phase cohort design. Methods Two cohorts of 682 patients each are sequentially recruited from 11 university-based German Centers for Rare Diseases (CRD): the standard care cohort (control, somatic expertise only) and the innovative care cohort (experimental, combined somatic and mental health expertise). Individuals aged 12 years and older presenting with symptoms and signs which are not explained by current diagnoses will be included. Data will be collected prior to the first visit to the CRD's outpatient clinic (T0), at the first visit (T1) and 12 months thereafter (T2). Outcomes Primary outcome is the percentage of patients with one or more confirmed diagnoses covering the symptomatic spectrum presented. Sample size is calculated to detect a 10 percent increase from 30\% in standard care to 40\% in the innovative dual expert cohort. Secondary outcomes are (a) time to diagnosis/diagnoses explaining the symptomatology; (b) proportion of patients successfully referred from CRD to standard care; (c) costs of diagnosis including incremental cost effectiveness ratios; (d) predictive value of screening instruments administered at T0 to identify patients with mental disorders; (e) patients' quality of life and evaluation of care; and f) physicians' satisfaction with the innovative care approach. Conclusions This is the first multi-center study to investigate the effects of a mental health specialist working in tandem with a somatic expert physician in CRDs. If this innovative approach proves successful, it will be made available on a larger scale nationally and promoted internationally. In the best case, ZSE-DUO can significantly shorten the time to diagnosis for a suspected rare disease.}, language = {en} } @article{LorenzMusacchioKunstmannetal.2022, author = {Lorenz, Delia and Musacchio, Thomas and Kunstmann, Erdmute and Grauer, Eva and Pluta, Natalie and Stock, Annika and Speer, Christian P. and Hebestreit, Helge}, title = {A case report of Sanfilippo syndrome - the long way to diagnosis}, series = {BMC Neurology}, volume = {22}, journal = {BMC Neurology}, number = {1}, doi = {10.1186/s12883-022-02611-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300465}, year = {2022}, abstract = {Background Mucopolysaccharidosis type III (Sanfilippo syndrome) is a lysosomal storage disorder, caused by a deficiency in the heparan-N-sulfatase enzyme involved in the catabolism of the glycosaminoglycan heparan sulfate. It is characterized by early nonspecific neuropsychiatric symptoms, followed by progressive neurocognitive impairment in combination with only mild somatic features. In this patient group with a broad clinical spectrum a significant genotype-phenotype correlation with some mutations leading to a slower progressive, attenuated course has been demonstrated. Case presentation Our patient had complications in the neonatal period and was diagnosed with Mucopolysaccharidosis IIIa only at the age of 28 years. He was compound heterozygous for the variants p.R245H and p.S298P, the latter having been shown to lead to a significantly milder phenotype. Conclusions The diagnostic delay is even more prolonged in this patient population with comorbidities and a slowly progressive course of the disease.}, language = {en} } @article{FreyLeutritzBackhausetal.2022, author = {Frey, Anna and Leutritz, Tobias and Backhaus, Joy and H{\"o}rnlein, Alexander and K{\"o}nig, Sarah}, title = {Item format statistics and readability of extended matching questions as an effective tool to assess medical students}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-25481-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300485}, year = {2022}, abstract = {Testing based on multiple choice questions (MCQ) is one of the most established forms of assessment, not only in the medical field. Extended matching questions (EMQ) represent a specific type of MCQ designed to require higher levels of cognition, such as problem-solving. The purpose of this evaluation was to assess the suitability and efficiency of EMQ as an assessment method. EMQ were incorporated into the end-of-semester examination in internal medicine, in which 154 students participated, and compared with three established MCQ types. Item and examination quality were investigated, as well as readability and processing time. EMQ were slightly more difficult to score; however, both item discrimination and discrimination index were higher when compared to other item types. EMQ were found to be significantly longer and required more processing time, but readability was improved. Students judged EMQ as clearly challenging, but attributed significantly higher clinical relevance when compared to established MCQ formats. Using the Spearman-Brown prediction, only ten EMQ items would be needed to reproduce the Cronbach's alpha value of 0.75 attained for the overall examination. EMQ proved to be both efficient and suitable when assessing medical students, demonstrating powerful characteristics of reliability. Their expanded use in favor of common MCQ could save examination time without losing out on statistical quality.}, language = {en} } @article{GramGenslerAlbertovaetal.2022, author = {Gram, Maximilian and Gensler, Daniel and Albertova, Petra and Gutjahr, Fabian Tobias and Lau, Kolja and Arias-Loza, Paula-Anahi and Jakob, Peter Michael and Nordbeck, Peter}, title = {Quantification correction for free-breathing myocardial T1ρ mapping in mice using a recursively derived description of a T\(_{1p}\)\(^{*}\) relaxation pathway}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {24}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, doi = {10.1186/s12968-022-00864-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300491}, year = {2022}, abstract = {Background Fast and accurate T1ρ mapping in myocardium is still a major challenge, particularly in small animal models. The complex sequence design owing to electrocardiogram and respiratory gating leads to quantification errors in in vivo experiments, due to variations of the T\(_{1p}\) relaxation pathway. In this study, we present an improved quantification method for T\(_{1p}\) using a newly derived formalism of a T\(_{1p}\)\(^{*}\) relaxation pathway. Methods The new signal equation was derived by solving a recursion problem for spin-lock prepared fast gradient echo readouts. Based on Bloch simulations, we compared quantification errors using the common monoexponential model and our corrected model. The method was validated in phantom experiments and tested in vivo for myocardial T\(_{1p}\) mapping in mice. Here, the impact of the breath dependent spin recovery time T\(_{rec}\) on the quantification results was examined in detail. Results Simulations indicate that a correction is necessary, since systematically underestimated values are measured under in vivo conditions. In the phantom study, the mean quantification error could be reduced from - 7.4\% to - 0.97\%. In vivo, a correlation of uncorrected T\(_{1p}\) with the respiratory cycle was observed. Using the newly derived correction method, this correlation was significantly reduced from r = 0.708 (p < 0.001) to r = 0.204 and the standard deviation of left ventricular T\(_{1p}\) values in different animals was reduced by at least 39\%. Conclusion The suggested quantification formalism enables fast and precise myocardial T\(_{1p}\) quantification for small animals during free breathing and can improve the comparability of study results. Our new technique offers a reasonable tool for assessing myocardial diseases, since pathologies that cause a change in heart or breathing rates do not lead to systematic misinterpretations. Besides, the derived signal equation can be used for sequence optimization or for subsequent correction of prior study results.}, language = {en} } @article{DengReinhardHennleinetal.2022, author = {Deng, Chunchu and Reinhard, Sebastian and Hennlein, Luisa and Eilts, Janna and Sachs, Stefan and Doose, S{\"o}ren and Jablonka, Sibylle and Sauer, Markus and Moradi, Mehri and Sendtner, Michael}, title = {Impaired dynamic interaction of axonal endoplasmic reticulum and ribosomes contributes to defective stimulus-response in spinal muscular atrophy}, series = {Translational Neurodegeneration}, volume = {11}, journal = {Translational Neurodegeneration}, number = {1}, issn = {2047-9158}, doi = {10.1186/s40035-022-00304-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300649}, year = {2022}, abstract = {Background: Axonal degeneration and defects in neuromuscular neurotransmission represent a pathological hallmark in spinal muscular atrophy (SMA) and other forms of motoneuron disease. These pathological changes do not only base on altered axonal and presynaptic architecture, but also on alterations in dynamic movements of organelles and subcellular structures that are not necessarily reflected by static histopathological changes. The dynamic interplay between the axonal endoplasmic reticulum (ER) and ribosomes is essential for stimulus-induced local translation in motor axons and presynaptic terminals. However, it remains enigmatic whether the ER and ribosome crosstalk is impaired in the presynaptic compartment of motoneurons with Smn (survival of motor neuron) deficiency that could contribute to axonopathy and presynaptic dysfunction in SMA. Methods: Using super-resolution microscopy, proximity ligation assay (PLA) and live imaging of cultured motoneurons from a mouse model of SMA, we investigated the dynamics of the axonal ER and ribosome distribution and activation. Results: We observed that the dynamic remodeling of ER was impaired in axon terminals of Smn-deficient motoneurons. In addition, in axon terminals of Smn-deficient motoneurons, ribosomes failed to respond to the brain-derived neurotrophic factor stimulation, and did not undergo rapid association with the axonal ER in response to extracellular stimuli. Conclusions: These findings implicate impaired dynamic interplay between the ribosomes and ER in axon terminals of motoneurons as a contributor to the pathophysiology of SMA and possibly also other motoneuron diseases.}, language = {en} } @article{MatsusakaChenAriasLozaetal.2022, author = {Matsusaka, Yohji and Chen, Xinyu and Arias-Loza, Paula and Werner, Rudolf A. and Nose, Naoko and Sasaki, Takanori and Rowe, Steven P. and Pomper, Martin G. and Lapa, Constantin and Higuchi, Takahiro}, title = {In Vivo Functional Assessment of Sodium-Glucose Cotransporters (SGLTs) Using [\(^{18}\)F]Me4FDG PET in Rats}, series = {Molecular Imaging}, volume = {2022}, journal = {Molecular Imaging}, doi = {10.1155/2022/4635171}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300708}, year = {2022}, abstract = {Background. Mediating glucose absorption in the small intestine and renal clearance, sodium glucose cotransporters (SGLTs) have emerged as an attractive therapeutic target in diabetic patients. A substantial fraction of patients, however, only achieve inadequate glycemic control. Thus, we aimed to assess the potential of the SGLT-targeting PET radiotracer alpha-methyl-4-deoxy-4-[\(^{18}\)F]fluoro-D-glucopyranoside ([\(^{18}\)F]Me4FDG) as a noninvasive intestinal and renal biomarker of SGLT-mediated glucose transport. Methods. We investigated healthy rats using a dedicated small animal PET system. Dynamic imaging was conducted after administration of the reference radiotracer 2-deoxy-2-[\(^{18}\)F]fluoro-D-glucose ([\(^{18}\)F]FDG), or the SGLT-targeting agent, [\(^{18}\)F]Me4FDG either directly into the digestive tract (for assessing intestinal absorption) or via the tail vein (for evaluating kidney excretion). To confirm the specificity of [18F]Me4FDG and responsiveness to treatment, a subset of animals was also pretreated with the SGLT inhibitor phlorizin. In this regard, an intraintestinal route of administration was used to assess tracer absorption in the digestive tract, while for renal assessment, phlorizin was injected intravenously (IV). Results. Serving as reference, intestinal administration of [\(^{18}\)F]FDG led to slow absorption with retention of \% of administered radioactivity at 15 min. [\(^{18}\)F]Me4FDG, however, was rapidly absorbed into the blood and cleared from the intestine within 15 min, leading to markedly lower tracer retention of \% (). Intraintestinal phlorizin led to marked increase of [\(^{18}\)F]Me4FDG uptake (15 min, \%; vs. untreated controls), supporting the notion that this PET agent can measure adequate SGLT inhibition in the digestive tract. In the kidneys, radiotracer was also sensitive to SGLT inhibition. After IV injection, [\(^{18}\)F]Me4FDG reabsorption in the renal cortex was significantly suppressed by phlorizin when compared to untreated animals (\%ID/g at 60 min, vs. untreated controls, ; ). Conclusion. As a noninvasive read-out of the concurrent SGLT expression in both the digestive tract and the renal cortex, [\(^{18}\)F]Me4FDG PET may serve as a surrogate marker for treatment response to SGLT inhibition. As such, [\(^{18}\)F]Me4FDG may enable improvement in glycemic control in diabetes by PET-based monitoring strategies.}, language = {en} } @article{SvenssonSharma2022, author = {Svensson, Sarah L. and Sharma, Cynthia M.}, title = {Small RNAs that target G-rich sequences are generated by diverse biogenesis pathways in Epsilonproteobacteria}, series = {Molecular Microbiology}, volume = {117}, journal = {Molecular Microbiology}, doi = {10.1111/mmi.14850}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259602}, pages = {215-233}, year = {2022}, abstract = {Bacterial small RNAs (sRNAs) are widespread post-transcriptional regulators that control bacterial stress responses and virulence. Nevertheless, little is known about how they arise and evolve. Homologs can be difficult to identify beyond the strain level using sequence-based approaches, and similar functionalities can arise by convergent evolution. Here, we found that the virulence-associated CJnc190 sRNA of the foodborne pathogen Campylobacter jejuni resembles the RepG sRNA from the gastric pathogen Helicobacter pylori. However, while both sRNAs bind G-rich sites in their target mRNAs using a C/U-rich loop, they largely differ in their biogenesis. RepG is transcribed from a stand-alone gene and does not require processing, whereas CJnc190 is transcribed from two promoters as precursors that are processed by RNase III and also has a cis-encoded antagonist, CJnc180. By comparing CJnc190 homologs in diverse Campylobacter species, we show that RNase III-dependent processing of CJnc190 appears to be a conserved feature even outside of C. jejuni. We also demonstrate the CJnc180 antisense partner is expressed in C. coli, yet here might be derived from the 3'UTR (untranslated region) of an upstream flagella-related gene. Our analysis of G-tract targeting sRNAs in Epsilonproteobacteria demonstrates that similar sRNAs can have markedly different biogenesis pathways.}, language = {en} } @phdthesis{Burd2022, author = {Burd, Paul Ray}, title = {Multiwavelength Probes of Physical Conditions in the Blazar Zone of AGN jets}, doi = {10.25972/OPUS-29700}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297001}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Context. In active galaxies, matter is accreted onto super massive black holes (SMBH). This accretion process causes a region roughly the size of our solar system to outshine the entire host galaxy, forming an active galactic nucleus (AGN). In some of these active galaxies, highly relativistic particle jets are formed parallel to the rotation axis of the super massive black hole. A fraction of these sources is observed under a small inclination angle between the pointing direction of the jet and the observing line of sight. These sources are called blazars. Due to the small inclination angle and the highly relativistic speeds of the particles in the jet, beaming effects occur in the radiation of these particles. Blazars can be subdivided into the high luminosity flat spectrum radio quasars (FSRQs) and the low luminosity BL Lacertae objects (BL Lacs). As all AGN, blazars are broadband emitters and therefore observable from the longest wavelengths in the radio regime to the shortest wavelengths in the gamma-ray regime. In this thesis I will analyze blazars at these two extremes with respect to their parsec-scale properties in the radio and their time evolution properties in gamma-ray flux. Method. In the radio regime the technique of very long baseline interferometry (VLBI) can be used in order to spatially resolve the synchrotron radiation coming from those objects down to sub-parsec scales. This information can be used to observe the time evolution of the structure of such sources. This is done in large monitoring programs such as the MOJAVE (15 GHz) and the Boston University blazar monitoring program (43 GHz). In this thesis I utilize data of 28 sources from these monitoring programs spanning 10 years of observation from 2003 to 2013, resulting in over 1800 observed epochs, to study the brightness temperature and diameter gradients of these jets. I conduct a search for systematic geometry transitions in the radio jets. The synchrotron cooling time in the radio core of the jets is used to determine the magnetic field strength in the radio core. Considering the jet geometry, these magnetic field strengths are scaled to the ergosphere of the SMBH in order to obtain the distance of the radio core to the SMBH. In the gamma-regime these blazars cannot be spatially resolved. Due to this, it is hard to put strong constrains onto where the gamma-ray emitting region is. Blazars have shown to be variable at high energies on time scales down to minutes. The nature of this variability can be studied in order to put constrains on the particle acceleration mechanism and possibly the region and size of the gamma-ray emitting region. The variability of blazars in the energy range between 0.1 GeV and 1 GeV can for example be observed with the pair-conversion telescope on board the Fermi satellite. I use 10 years of data from the Fermi-LAT (LAT: Large Area Telescope) satellite in order to study the variability of a large sample of blazars (300-800, depending on the used significance filters for data points). I quantify this variability with the Ornstein-Uhlenbeck (OU) parameters and the power spectral density (PSD) slopes. The same procedure is applied to 20 light curves available for the radio sample. Results. The diameter evolution along the jet axis of the radio sources suggests, that FSRQs feature flatter gradients than BL Lacs. Fitting these gradients, it is revealed that BL Lacs are systematically better described by a simple single power law than FSRQs. I found 9 sources with a strongly constrained geometry transition. The sources are 0219+421, 0336-019, 0415+379, 0528+134, 0836+710, 1101+384, 1156+295, 1253-055 and 2200+420. In all of these sources, the geometry transition regions are further out in the jet than the Bondi sphere. The magnetic field strengths of BL Lacs is systematically larger than that of FSRQs. However the scaling of these fields suggest that the radio cores of BL Lac objects are closer to the SMBHs than the radio cores of FSRQs. Analyzing the variability of Fermi-LAT light curves yields consistent results for all samples. FSRQs show systematically steeper PSD slopes and feature OU parameters more favorable to strong variability than BL Lacs. The Fermi-LAT light curves of the sub-sample of radio jets, suggest an anticorrelation between the jet complexity from the radio observations and the OU-parameters as well as the PSD slopes from the gamma-ray observations. Conclusion. The flatter diameter gradients of FSRQs suggest that these sources are more collimated further down the jet than BL Lacs. The systematically better description of the diameter and brightness temperature gradient by a single power law of BL Lacs, suggest that FSRQs are more complex with respect to the diameter evolution along the jet and the surface brightness distribution than BL Lac objects. FSRQs often feature regions where recollimation can occur in distinct knots within the jets. For the sources where a geometry transition could be constrained, the Bondi radius, being systematically smaller than the position of the transition region along the jet axis, suggest that changing pressure gradients are not the sole cause for these systematic geometry transitions. Nevertheless they may be responsible for recollimation regions, found typically downstream the jet, beyond the Bondi radius and the transition zone. The difference in the distance of the radio cores between FSRQs and BL Lacs is most likely due to the combination of differences in SMBH masses and systematically smaller jet powers in BL Lacs. The variability in energy ranges above 100 MeV and above 1 GeV-regime suggest that many light curves of BL Lac objects are more likely to be white noise while the PSD slopes and the OU parameters of FSRQ gamma-ray light curves favor stronger variability on larger time scales with respect to the time binning of the analyzed light curve. Although the anticorrelation of the jet complexity acquired from the radio observations and the PSD slopes and OU parameters from the gamma-observations suggest that more complex sources favor OU parameters and PSD slopes resulting in more variability (not white noise) it is beyond the scope of this thesis to pinpoint whether this correlation results from causation. The question whether a complex jet causes more gamma-ray variability or more gamma-ray variability causes more complex jets cannot be answered at this point. Nevertheless the computed correlation measures suggest that this dependence is most likely not linear and therefore an indication that these effects might even interact.}, language = {en} } @article{KosmalaSerflingDreheretal.2022, author = {Kosmala, Aleksander and Serfling, Sebastian E. and Dreher, Niklas and Lindner, Thomas and Schirbel, Andreas and Lapa, Constantin and Higuchi, Takahiro and Buck, Andreas K. and Weich, Alexander and Werner, Rudolf A.}, title = {Associations between normal organs and tumor burden in patients imaged with fibroblast activation protein inhibitor-directed positron emission tomography}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {11}, issn = {2072-6694}, doi = {10.3390/cancers14112609}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275154}, year = {2022}, abstract = {(1) Background: We aimed to quantitatively investigate [\(^{68}\)Ga]Ga-FAPI-04 uptake in normal organs and to assess a relationship with the extent of FAPI-avid tumor burden. (2) Methods: In this single-center retrospective analysis, thirty-four patients with solid cancers underwent a total of 40 [\(^{68}\)Ga]Ga-FAPI-04 PET/CT scans. Mean standardized uptake values (SUV\(_{mean}\)) for normal organs were established by placing volumes of interest (VOIs) in the heart, liver, spleen, pancreas, kidneys, and bone marrow. Total tumor burden was determined by manual segmentation of tumor lesions with increased uptake. For tumor burden, quantitative assessment included maximum SUV (SUV\(_{max}\)), tumor volume (TV), and fractional tumor activity (FTA = TV × SUV\(_{mean}\)). Associations between uptake in normal organs and tumor burden were investigated by applying Spearman's rank correlation coefficient. (3) Results: Median SUV\(_{mean}\) values were 2.15 in the pancreas (range, 1.05-9.91), 1.42 in the right (range, 0.57-3.06) and 1.41 in the left kidney (range, 0.73-2.97), 1.2 in the heart (range, 0.46-2.59), 0.86 in the spleen (range, 0.55-1.58), 0.65 in the liver (range, 0.31-2.11), and 0.57 in the bone marrow (range, 0.26-0.94). We observed a trend towards significance for uptake in the myocardium and tumor-derived SUV\(_{max}\) (ρ = 0.29, p = 0.07) and TV (ρ = -0.30, p = 0.06). No significant correlation was achieved for any of the other organs: SUV\(_{max}\) (ρ ≤ 0.1, p ≥ 0.42), TV (ρ ≤ 0.11, p ≥ 0.43), and FTA (ρ ≤ 0.14, p ≥ 0.38). In a sub-analysis exclusively investigating patients with high tumor burden, significant correlations of myocardial uptake with tumor SUV\(_{max}\) (ρ = 0.44; p = 0.03) and tumor-derived FTA with liver uptake (ρ = 0.47; p = 0.02) were recorded. (4) Conclusions: In this proof-of-concept study, quantification of [\(^{68}\)Ga]Ga-FAPI-04 PET showed no significant correlation between normal organs and tumor burden, except for a trend in the myocardium. Those preliminary findings may trigger future studies to determine possible implications for treatment with radioactive FAP-targeted drugs, as higher tumor load or uptake may not lead to decreased doses in the majority of normal organs.}, language = {en} } @phdthesis{Hoeser2022, author = {H{\"o}ser, Thorsten}, title = {Global Dynamics of the Offshore Wind Energy Sector Derived from Earth Observation Data - Deep Learning Based Object Detection Optimised with Synthetic Training Data for Offshore Wind Energy Infrastructure Extraction from Sentinel-1 Imagery}, doi = {10.25972/OPUS-29285}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-292857}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The expansion of renewable energies is being driven by the gradual phaseout of fossil fuels in order to reduce greenhouse gas emissions, the steadily increasing demand for energy and, more recently, by geopolitical events. The offshore wind energy sector is on the verge of a massive expansion in Europe, the United Kingdom, China, but also in the USA, South Korea and Vietnam. Accordingly, the largest marine infrastructure projects to date will be carried out in the upcoming decades, with thousands of offshore wind turbines being installed. In order to accompany this process globally and to provide a database for research, development and monitoring, this dissertation presents a deep learning-based approach for object detection that enables the derivation of spatiotemporal developments of offshore wind energy infrastructures from satellite-based radar data of the Sentinel-1 mission. For training the deep learning models for offshore wind energy infrastructure detection, an approach is presented that makes it possible to synthetically generate remote sensing data and the necessary annotation for the supervised deep learning process. In this synthetic data generation process, expert knowledge about image content and sensor acquisition techniques is made machine-readable. Finally, extensive and highly variable training data sets are generated from this knowledge representation, with which deep learning models can learn to detect objects in real-world satellite data. The method for the synthetic generation of training data based on expert knowledge offers great potential for deep learning in Earth observation. Applications of deep learning based methods can be developed and tested faster with this procedure. Furthermore, the synthetically generated and thus controllable training data offer the possibility to interpret the learning process of the optimised deep learning models. The method developed in this dissertation to create synthetic remote sensing training data was finally used to optimise deep learning models for the global detection of offshore wind energy infrastructure. For this purpose, images of the entire global coastline from ESA's Sentinel-1 radar mission were evaluated. The derived data set includes over 9,941 objects, which distinguish offshore wind turbines, transformer stations and offshore wind energy infrastructures under construction from each other. In addition to this spatial detection, a quarterly time series from July 2016 to June 2021 was derived for all objects. This time series reveals the start of construction, the construction phase and the time of completion with subsequent operation for each object. The derived offshore wind energy infrastructure data set provides the basis for an analysis of the development of the offshore wind energy sector from July 2016 to June 2021. For this analysis, further attributes of the detected offshore wind turbines were derived. The most important of these are the height and installed capacity of a turbine. The turbine height was calculated by a radargrammetric analysis of the previously detected Sentinel-1 signal and then used to statistically model the installed capacity. The results show that in June 2021, 8,885 offshore wind turbines with a total capacity of 40.6 GW were installed worldwide. The largest installed capacities are in the EU (15.2 GW), China (14.1 GW) and the United Kingdom (10.7 GW). From July 2016 to June 2021, China has expanded 13 GW of offshore wind energy infrastructure. The EU has installed 8 GW and the UK 5.8 GW of offshore wind energy infrastructure in the same period. This temporal analysis shows that China was the main driver of the expansion of the offshore wind energy sector in the period under investigation. The derived data set for the description of the offshore wind energy sector was made publicly available. It is thus freely accessible to all decision-makers and stakeholders involved in the development of offshore wind energy projects. Especially in the scientific context, it serves as a database that enables a wide range of investigations. Research questions regarding offshore wind turbines themselves as well as the influence of the expansion in the coming decades can be investigated. This supports the imminent and urgently needed expansion of offshore wind energy in order to promote sustainable expansion in addition to the expansion targets that have been set.}, language = {en} } @phdthesis{Wendel2022, author = {Wendel, Christoph}, title = {Spectral Imprints from Electromagnetic Cascades in Blazar Jets}, doi = {10.25972/OPUS-29007}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290076}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The extragalactic gamma-ray sky is dominated by blazars, active galactic nuclei (AGN) with a relativistic jet that is closely aligned with the line of sight. Galaxies develop an active nucleus if the central supermassive black hole (BH) accretes large amounts of ambient matter and magnetic flux. The inflowing mass accumulates around the plane perpendicular to the accretion flow's angular momentum. The flow is heated through viscous friction and part of the released energy is radiated as blackbody or non-thermal radiation, with luminosities that can dominate the accumulated stellar luminosity of the host galaxy. A fraction of the accretion flow luminosity is reprocessed in a surrounding field of ionised gas clouds. These clouds, revolving around the central BH, emit Doppler-broadened atomic emission lines. The region where these broad-line-emitting clouds are located is called broad-line region (BLR). About one in ten AGN forms an outflow of radiation and relativistic particles, called a relativistic jet. According to the Blandford-Znajek mechanism, this is facilitated through electromagnetic processes in the magnetosphere of a spinning BH. The latter induces a magnetospheric poloidal current circuit, generating a decelerating torque on the BH and inducing a toroidal magnetic field. Consequently, rotational energy of the BH is converted to Poynting flux streaming away mainly along the rotational axis and starting the jet. One possibility for particle acceleration near the jet base is realised by magnetospheric vacuum gaps, regions temporarily devoid of plasma, such that an intermittent electric field arises parallel to the magnetic field lines, enabling particle acceleration and contributing to the mass loading of the jets. Magnetised structures, containing bunches of relativistic electrons, propagate away from the galactic nucleus along the jets. Assuming that these electrons emit synchrotron radiation and that they inverse-Compton (IC) up-scatter abundant target photons, which can either be the synchrotron photons themselves or photons from external emitters, the emitted spectrum can be theoretically determined. Additionally taking into account that these emission regions move relativistically themselves and that the emission is Doppler-boosted and beamed in forward direction, the typical two-hump spectral energy distribution (SED) of blazars is recovered. There are however findings that challenge this well-established model. Short-time variability, reaching down to minute scales at very high energy gamma rays, is today known to be a widespread phenomenon of blazars, calling for very compact emission regions. In most models of such optically thick emission regions, the gamma-ray flux is usually pair-absorbed exponentially, without considering the cascade evolving from the pair-produced electrons. From the observed flux, it is often concluded that emission emanates from larger distances where the region is optically thin, especially from outside of the BLR. Only in few blazars gamma-ray attenuation associated with pair absorption in the BLR was clearly reported. With the advent of sophisticated high-energy or very high energy gamma-ray detectors, like the Fermi Large Area Telescope or the Major Atmospheric Gamma-ray Imaging Cherenkov telescopes, besides the extraordinarily fast variability spectral features have been found that cannot be explained by conventional models reproducing the two-hump SED. Two such narrow spectral features are discussed in this work. For the nearby blazar Markarian 501, hints to a sharp peak around 3 TeV have been reported from a multi-wavelength campaign carried out in July 2014, while for 3C 279 a spectral dip was found in 2018 data, that can hardly be described with conventional fitting functions. In this work it is examined whether these spectral peculiarities of blazar jet emission can be explained, if the full radiation reprocessing through an IC pair cascade is accounted for. Such a cascade is the multiple concatenation of IC scattering events and pair production events. In the cascades generally considered in this work, relativistic electrons and high-energy photons are injected into a fixed soft target photon field. A mathematical description for linear IC pair cascades with escape terms is delivered on the basis of preliminary works. The steady-state kinetic equations for the electrons and for the photons are determined, whereby it is paid attention to an explicit formulation and to motivating the correct integration borders of all integrals from kinematic constraints. In determining the potentially observable gamma-ray flux, both the attenuated injected flux and the flux evolving as an effect of IC up-scattering, pair absorption and escape are incorporated, giving the emerging spectra very distinct imprints. Much effort is dedicated to the numerical solution of the electrons' kinetic equation via iterative schemes. It is explained why pointwise iteration from higher to lower Lorentz factors is more efficient than iterating the whole set of sampling points. The algorithm is parallelised at two positions. First, several workers can perform pointwise iterations simultaneously. Second, the most demanding integral is cut into a number of part integrals which can be determined by multiple workers. Through these measures, the Python code can be readily applied to simulate steady-state IC pair cascades with escape. In the case of Markarian 501 the developed framework is as follows. The AGN hosts an advection-dominated accretion flow with a normalised accretion rate of several \(10^{-4}\) and an electron temperature near \(10^{10}\) K. On the one hand, the accretion flow illuminates the few ambient gas clouds with approximate radius \(10^{11}\) m, which reprocess a fraction 0.01 of the luminosity into hydrogen and helium emission lines. On the other hand, the gamma rays from the accretion flow create electrons and positrons in a sporadically active vacuum gap in the BH magnetosphere. In the active gap, a power of roughly 0.001 of the Blandford-Znajek power is extracted from the rotating BH through a gap potential drop of several \(10^{18}\) V, generating ultra-relativistic electrons, which subsequently are multiplied by a factor of about \(10^6\) through interaction with the accretion flow photons. This electron beam propagates away from the central engine and encounters the photon field of one passing ionised cloud. The resulting IC pair cascade is simulated and the evolving gamma-ray spectrum is determined. Just above the absorption troughs due to the hydrogen lines, the spectrum exhibits a narrow bump around 3 TeV. When the cascaded emission is added to the emission generated at larger distances, the observed multi-wavelength SED including the sharp peak at 3 TeV is reproduced, underlining that radiation processes beyond conventional models are motivated by distinct spectral features. The dip in the spectrum of 3C 279 is addressed by a similar cascade model. Three types of injection are considered, varying in the ratio of the photon density to the electron density and varying in the spectral shape. The IC pair cascade is assumed to happen either in the dense BLR photon field with a luminosity of several \(10^{37}\) W and a radial size of few \(10^{14}\) m or in the diluted photon field outside of the BLR. The latter scenario is however rejected as the spectral slope around several 100 MeV and the dip at few 10 GeV cannot be reconciled within this model. The radiation cascaded in the BLR can explain the observational data, irrespective of the assumed injected rate. It is therefore concluded that for this period of gamma-ray emission, the radiation production happens at the edge of the BLR of 3C 279. Both investigations show that IC pair cascades can account for fine structure seen in blazar SEDs. It is insufficient to restrict the radiation transport to pure exponential absorption of an injection term. Pair production and IC up-scattering by all generations of photons and electrons in the optically thick regime critically shape the emerging spectra. As the advent of future improved detectors will provide more high-precision spectra, further observations of narrow spectral features can be expected. It seems therefore recommendable to incorporate cascading into conventional radiation production models or to extend the model developed in this work by synchrotron radiation.}, subject = {Active galactic nucleus}, language = {en} } @article{StoevesandtTrautmann2022, author = {Stoevesandt, Johanna and Trautmann, Axel}, title = {Risk factors in bee and Vespula venom allergy: state of the art}, series = {Allergo Journal International}, volume = {31}, journal = {Allergo Journal International}, number = {1}, issn = {2197-0378}, doi = {10.1007/s40629-021-00187-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270498}, pages = {1-10}, year = {2022}, abstract = {Background Correct recognition of risk factors enables individualized management and treatment of venom allergic patients. Methods Systematic research and review of current literature regarding the risk of (1) severe sting-induced anaphylaxis, (2) anaphylactic adverse event during venom immunotherapy (VIT), and (3) treatment failure. Results and discussion (1) Mastocytosis is the most important risk factor for severe sting-induced anaphylaxis. Hereditary α‑tryptasemia was recently identified as a genetic predictor of severe reactions. Older age is clearly associated with an increased risk; the respective impact of defined cardiovascular comorbidities has yet to be determined. Recent data do not support an aggravation of venom-induced anaphylaxis by intake of β‑blockers or angiotensin-converting enzyme (ACE) inhibitors. A higher risk in men can be attributed to more intensive exposure to stinging insects. (2) Anaphylactic side effects of VIT are most common during the buildup phase, particularly in the course of (ultra-)rush protocols involving a high number of injections and high cumulative daily doses. They are significantly more frequent during honeybee compared to Vespula VIT. Data supporting a negative effect of mastocytosis on the tolerability of VIT are scarce. Older age and cardiovascular medication are not associated with a higher incidence of VIT-induced anaphylaxis. (3) Relapsing anaphylactic reactions to both field and challenge stings are significantly more common during and after honeybee compared to Vespula VIT. Reports of severe field-sting reactions in mastocytosis patients suggest an increased risk of treatment failure which may be overcome by higher maintenance doses and longer duration of VIT.}, language = {en} } @article{RamlerSchwarzmannStoyetal.2022, author = {Ramler, Jacqueline and Schwarzmann, Johannes and Stoy, Andreas and Lichtenberg, Crispin}, title = {Two Faces of the Bi-O Bond: Photochemically and Thermally Induced Dehydrocoupling for Si-O Bond Formation}, series = {European Journal of Inorganic Chemistry}, volume = {2022}, journal = {European Journal of Inorganic Chemistry}, number = {7}, doi = {10.1002/ejic.202100934}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257428}, year = {2022}, abstract = {The diorgano(bismuth)alcoholate [Bi((C\(_{6}\)H\(_{4}\)CH\(_{2}\))\(_{2}\)S)OPh] (1-OPh) has been synthesized and fully characterized. Stoichiometric reactions, UV/Vis spectroscopy, and (TD-)DFT calculations suggest its susceptibility to homolytic and heterolytic Bi-O bond cleavage under given reaction conditions. Using the dehydrocoupling of silanes with either TEMPO or phenol as model reactions, the catalytic competency of 1-OPh has been investigated (TEMPO=(tetramethyl-piperidin-1-yl)-oxyl). Different reaction pathways can deliberately be addressed by applying photochemical or thermal reaction conditions and by choosing radical or closed-shell substrates (TEMPO vs. phenol). Applied analytical techniques include NMR, UV/Vis, and EPR spectroscopy, mass spectrometry, single-crystal X-ray diffraction analysis, and (TD)-DFT calculations.}, language = {en} } @article{KayaZeebEngelmayerStrassburgeretal.2022, author = {Kaya-Zeeb, Sinan and Engelmayer, Lorenz and Straßburger, Mara and Bayer, Jasmin and B{\"a}hre, Heike and Seifert, Roland and Scherf-Clavel, Oliver and Thamm, Markus}, title = {Octopamine drives honeybee thermogenesis}, series = {eLife}, volume = {11}, journal = {eLife}, doi = {10.7554/eLife.74334}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301327}, year = {2022}, abstract = {In times of environmental change species have two options to survive: they either relocate to a new habitat or they adapt to the altered environment. Adaptation requires physiological plasticity and provides a selection benefit. In this regard, the Western honeybee (Apis mellifera) protrudes with its thermoregulatory capabilities, which enables a nearly worldwide distribution. Especially in the cold, shivering thermogenesis enables foraging as well as proper brood development and thus survival. In this study, we present octopamine signaling as a neurochemical prerequisite for honeybee thermogenesis: we were able to induce hypothermia by depleting octopamine in the flight muscles. Additionally, we could restore the ability to increase body temperature by administering octopamine. Thus, we conclude that octopamine signaling in the flight muscles is necessary for thermogenesis. Moreover, we show that these effects are mediated by β octopamine receptors. The significance of our results is highlighted by the fact the respective receptor genes underlie enormous selective pressure due to adaptation to cold climates. Finally, octopamine signaling in the service of thermogenesis might be a key strategy to survive in a changing environment.}, language = {en} }