@article{PetritschPannbeckerWengetal.2021,
  author    = {Petritsch, Bernhard and Pannbecker, Pauline and Weng, Andreas M. and Grunz, Jan-Peter and Veldhoen, Simon and Bley, Thorsten A. and Kosmala, Aleksander},
  title     = {Split-filter dual-energy CT pulmonary angiography for the diagnosis of acute pulmonary embolism: a study on image quality and radiation dose},
  series = {Quantitative Imaging in Medicine and Surgery},
  volume    = {11},
  journal   = {Quantitative Imaging in Medicine and Surgery},
  number    = {5},
  doi       = {10.21037/qims-20-740},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231456},
  pages     = {1817-1827},
  year      = {2021},
  abstract  = {Background: Computed tomography (CT) pulmonary angiography is the diagnostic reference standard in suspected pulmonary embolism (PE). Favorable results for dual-energy CT (DECT) images have been reported for this condition. Nowadays, dual-energy data acquisition is feasible with different technical options, including a single-source split-filter approach. Therefore, the aim of this retrospective study was to investigate image quality and radiation dose of thoracic split-filter DECT in comparison to conventional single-energy CT in patients with suspected PE. Methods: A total of 110 CT pulmonary angiographies were accomplished either as standard single-energy CT with automatic tube voltage selection (ATVS) (n=58), or as split-filter DECT (n=52). Objective [pulmonary artery CT attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)] and subjective image quality [four-point Likert scale; three readers (R)] were compared among the two study groups. Size-specific dose estimates (SSDE), dose-length-product (DLP) and volume CT dose index (CTDIvol) were assessed for radiation dose analysis. Results: Split-filter DECT images yielded 67.7\% higher SNR (27.0 vs. 16.1; P<0.001) and 61.9\% higher CNR (22.5 vs. 13.9; P<0.001) over conventional single-energy images, whereas CT attenuation was significantly lower (344.5 vs. 428.2 HU; P=0.013). Subjective image quality was rated good or excellent in 93.0\%/98.3\%/77.6\% (R1/R2/R3) of the single-energy CT scans, and 84.6\%/82.7\%/80.8\% (R1/R2/R3) of the split-filter DECT scans. SSDE, DLP and CTDIvol were significantly lower for conventional single-energy CT compared to split-filter DECT (all P<0.05), which was associated with 26.7\% higher SSDE. Conclusions: In the diagnostic workup of acute PE, the split-filter allows for dual-energy data acquisition from single-source single-layer CT scanners. The existing opportunity to assess pulmonary "perfusion" based on analysis of iodine distribution maps is associated with higher radiation dose in terms of increased SSDE than conventional single-energy CT with ATVS. Moreover, a proportion of up to 3.8\% non-diagnostic examinations in the current reference standard test for PE is not negligible.},
  language  = {en}
}
@article{KramerMeyerNatusStigloheretal.2021,
  author    = {Kramer, Susanne and Meyer-Natus, Elisabeth and Stigloher, Christian and Thoma, Hanna and Schnaufer, Achim and Engstler, Markus},
  title     = {Parallel monitoring of RNA abundance, localization and compactness with correlative single molecule FISH on LR White embedded samples},
  series = {Nucleic Acids Research},
  volume    = {49},
  journal   = {Nucleic Acids Research},
  number    = {3},
  doi       = {10.1093/nar/gkaa1142},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230647},
  year      = {2021},
  abstract  = {Single mRNA molecules are frequently detected by single molecule fluorescence in situ hybridization (smFISH) using branched DNA technology. While providing strong and background-reduced signals, the method is inefficient in detecting mRNAs within dense structures, in monitoring mRNA compactness and in quantifying abundant mRNAs. To overcome these limitations, we have hybridized slices of high pressure frozen, freeze-substituted and LR White embedded cells (LR White smFISH). mRNA detection is physically restricted to the surface of the resin. This enables single molecule detection of RNAs with accuracy comparable to RNA sequencing, irrespective of their abundance, while at the same time providing spatial information on RNA localization that can be complemented with immunofluorescence and electron microscopy, as well as array tomography. Moreover, LR White embedding restricts the number of available probe pair recognition sites for each mRNA to a small subset. As a consequence, differences in signal intensities between RNA populations reflect differences in RNA structures, and we show that the method can be employed to determine mRNA compactness. We apply the method to answer some outstanding questions related to trans-splicing, RNA granules and mitochondrial RNA editing in single-cellular trypanosomes and we show an example of differential gene expression in the metazoan Caenorhabditis elegans.},
  language  = {en}
}
@article{Khaled2021,
  author    = {Khaled, Mohamed Ismail},
  title     = {Nomes of Lower Egypt in the early Fifth Dynasty},
  series = {E\&G Quaternary Science Journal},
  volume    = {70},
  journal   = {E\&G Quaternary Science Journal},
  number    = {1},
  doi       = {10.5194/egqsj-70-19-2021},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230350},
  pages     = {19-27},
  year      = {2021},
  abstract  = {Having control over the landscape played an important role in the geography and economy of Egypt from the predynastic period onwards. Especially from the beginning of the Old Kingdom, we have evidence that kings created new places (funerary domains) called (centers) and (Ezbah) for the equipment of the building projects of the royal tomb and the funerary cult of the king, as well as to ensure the eternal life of both kings and individuals. Kings used these localities in order to do so, and they oftentimes expanded the border of an existing nome and created new establishments. Consequently, these establishments were united or divided into new nomes. The paper discusses the geography of Lower Egypt and the associated royal domains in the early Fifth Dynasty based on the new discoveries from the causeway of Sahura at Abusir.},
  language  = {en}
}
@article{AlbertLeziusStoerketal.2021,
  author    = {Albert, Judith and Lezius, Susanne and St{\"o}rk, Stefan and Morbach, Caroline and G{\"u}der, G{\"u}lmisal and Frantz, Stefan and Wegscheider, Karl and Ertl, Georg and Angermann, Christiane E.},
  title     = {Trajectories of Left Ventricular Ejection Fraction After Acute Decompensation for Systolic Heart Failure: Concomitant Echocardiographic and Systemic Changes, Predictors, and Impact on Clinical Outcomes},
  series = {Journal of the American Heart Association},
  volume    = {10},
  journal   = {Journal of the American Heart Association},
  doi       = {10.1161/JAHA.120.017822},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230210},
  year      = {2021},
  abstract  = {Prospective longitudinal follow-up of left ventricular ejection fraction (LVEF) trajectories after acute cardiac decompensation of heart failure is lacking. We investigated changes in LVEF and covariates at 6-months' follow-up in patients with a predischarge LVEF ≤40\%, and determined predictors and prognostic implications of LVEF changes through 18-months' follow-up. Methods and Results Interdisciplinary Network Heart Failure program participants (n=633) were categorized into subgroups based on LVEF at 6-months' follow-up: normalized LVEF (>50\%; heart failure with normalized ejection fraction, n=147); midrange LVEF (41\%-50\%; heart failure with midrange ejection fraction, n=195), or persistently reduced LVEF (≤40\%; heart failure with persistently reduced LVEF , n=291). All received guideline-directed medical therapies. At 6-months' follow-up, compared with patients with heart failure with persistently reduced LVEF, heart failure with normalized LVEF or heart failure with midrange LVEF subgroups showed greater reductions in LV end-diastolic/end-systolic diameters (both P<0.001), and left atrial systolic diameter (P=0.002), more increased septal/posterior end-diastolic wall-thickness (both P<0.001), and significantly greater improvement in diastolic function, biomarkers, symptoms, and health status. Heart failure duration <1 year, female sex, higher predischarge blood pressure, and baseline LVEF were independent predictors of LVEF improvement. Mortality and event-free survival rates were lower in patients with heart failure with normalized LVEF (P=0.002). Overall, LVEF increased further at 18-months' follow-up (P<0.001), while LV end-diastolic diameter decreased (P=0.048). However, LVEF worsened (P=0.002) and LV end-diastolic diameter increased (P=0.047) in patients with heart failure with normalized LVEF hospitalized between 6-months' follow-up and 18-months' follow-up. Conclusions Six-month survivors of acute cardiac decompensation for systolic heart failure showed variable LVEF trajectories, with >50\% showing improvements by ≥1 LVEF category. LVEF changes correlated with various parameters, suggesting multilevel reverse remodeling, were predictable from several baseline characteristics, and were associated with clinical outcomes at 18-months' follow-up. Repeat hospitalizations were associated with attenuation of reverse remodeling."},
  language  = {en}
}
@phdthesis{Roos2021,
  author    = {Roos, Markus},
  title     = {Synthesis, Photophysics and Photocatalysis of [FeFe] Complex Containing Dyads and Bimolecular Systems},
  doi       = {10.25972/OPUS-23453},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234537},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {In the course of this work, a total of three photocatalytically active dyads for proton reduction could be synthesized together with the associated individual components. Two of them, D1 and D2, comprised a [Ru(bpy)3]2+ photosensitizer and D3 an [Ir(ppy)2bpy]+ photosensitizer. A Ppyr3-substituted propyldithiolate [FeFe] complex was used as catalyst in all systems. The absorption spectroscopic and electrochemical investigations showed that an inner-dyadic electronic coupling is effectively prevented in the dyads due to conjugation blockers within the bridging units used. The photocatalytic investigations exhibited that all dyad containing two-component systems (2CS) showed a significantly worse performance than the corresponding bimolecular three-component systems (3CS). Transient absorption spectroscopy showed that the 2CS behave very similarly to the associated multicomponent systems during photocatalysis. The electron that was intended for the intramolecular transfer from the photosensitizer unit to the catalyst unit within the dyads remains at the photosensitizer for a relatively long time, analogous to the 3CS and despite the covalently bound catalyst. It is therefore assumed that this intramolecular electron transfer is likely to be hindered as a result of the weak electronic coupling caused by the bridge units used. Instead, the system bypasses this through an intermolecular transfer to other dyad molecules in the immediate vicinity. In addition, with the help of emission quenching experiments and electrochemical investigations, it could be clearly concluded that all investigated systems proceed via the reductive quenching mechanism during photocatalysis.},
  subject      = {Fotokatalyse},
  language  = {en}
}
@phdthesis{Goos2021,
  author    = {Goos, Carina},
  title     = {Nuclear periphery granules of trypanosomes - A characterization of composition and function},
  doi       = {10.25972/OPUS-23436},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234368},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The nuclear envelope serves as important mRNA surveillance system. In yeast and humans, several control mechanisms act in parallel to prevent nuclear export of unprocessed mRNAs. However, trypanosomes lack homologues to most of the proteins involved. In addition, gene expression in trypanosomes relies almost completely on post-transcriptional regulation as they transcribe mRNAs as long polycistrons, which are subsequently processed into individual mRNA molecules by trans-splicing. As trans-splicing is not error-free, unspliced mRNAs may be recognized and prevented from reaching the cytoplasm by a yet unknown mechanism. When trans-splicing is inhibited in trypanosomes, the formation of a novel RNA granule type at the cytoplasmic periphery of the nucleus, so called nuclear periphery granules (NPGs) was previously observed. To identify potential regulators of nuclear export control, changes in protein localization which occur when trans-splicing is inhibited, were globally analyzed during this work. For this, trypanosome nuclei were purified under conditions maintaining NPG attachment to the nucleus, in the absence and presence of trans-splicing. Mass spectrometry analyses identified 128 proteins which are specifically enriched in nuclear preparations of cells inhibited for trans-splicing. Amongst them are proteins, which change their localization to the nucleus or to the nuclear pores as well as many proteins that move into NPGs. Some of these proteins are promising candidates for nuclear export control proteins, as the changes in localization (to the nucleus or nuclear pores) were specific to the accumulation of unspliced mRNAs. The NPG proteome almost exclusively contains proteins involved in mRNA metabolism, mostly unique to trypanosomes, notably major translation initiation factors were absent. These data indicate that NPGs are RNP complexes which have started or completed nuclear export, but not yet entered translation. As a byproduct of these proteomic studies, a high-quality dataset of the yet unknown T. brucei nuclear proteome is provided, closing an important gap in knowledge to study trypanosome biology, in particular nuclear related processes. NPGs were characterized in more detail by microscopy. The granules are cytoplasmic and present in at least two different trypanosome life cycle stages. There are at least two distinct granule subsets, with differences in protein composition. A closer analysis of NPGs by electron microscopy revealed that the granules are electron dense structures, which are connected to nuclear pores by string-like structures. In order to approach the function of NPGs, on the one hand, the hypothesis that NPGs might be related to perinuclear germ granules of adult gonads of C. elegans was tested: we found no relation between the two granule types. On the other hand, initial single molecule mRNA FISH experiments performed in trypanosomes showed no accumulation of unspliced transcripts in NPGs, arguing against an involvement of the granules in mRNA quality control.},
  subject      = {Trypanosoma brucei},
  language  = {en}
}
@phdthesis{Gupta2021,
  author    = {Gupta, Rohini},
  title     = {Intracellular self-activation of the TrkB kinase domain causes FAK phosphorylation and disrupts actin filopodia dynamics},
  doi       = {10.25972/OPUS-23382},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233829},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The tropomysin receptor kinase B (TrkB), the receptor for the neurotrophin brain-derived neurotrophic factor (BDNF), plays an important role in neuronal survival, neuronal differentiation, and cellular plasticity. Conventionally, TrkB activation is induced by binding of BDNF at extracellular sites and subsequent dimerization of receptor monomers. Classical Trk signaling concepts have failed to explain ligand-independent signaling of intracellular TrkB or oncogenic NTRK-fusion proteins. The intracellular activation domain of TrkB consists of a tyrosine kinase core, with three tyrosine (Y) residues at positions 701, 705 and 706, that catalyzes the phosphorylation reaction between ATPγ and tyrosine. The release of cisautoinhibition of the kinase domain activates the kinase domain and tyrosine residues outside of the catalytic domain become phosphorylated. The aim of this study was to find out how ligand-independent activation of TrkB is brought about. With the help of phosphorylation mutants of TrkB, it has been found that a high, local abundance of the receptor is sufficient to activate TrkB in a ligand-independent manner. This self-activation of TrkB was blocked when either the ATP-binding site or Y705 in the core domain was mutated. The vast majority of this self-active TrkB was found at intracellular locations and was preferentially seen in roundish cells, lacking filopodia. Live cell imaging of actin dynamics showed that self-active TrkB changed the cellular morphology by reducing actin filopodia formation. Signaling cascade analysis confirmed that self-active TrkB is a powerful activator of focal adhesion kinase (FAK). This might be the reason why self-active TrkB is able to disrupt actin filopodia formation. The signaling axis from Y705 to FAK could be mimicked by expression of the soluble, cytosolic TrkB kinase domain. However, the signaling pathway was inactive, when the TrkB kinase domain was targeted to the plasmamembrane with the help of artificial myristoylation membrane anchors. A cancer-related intracellular NTRK2-fusion protein (SQSTM1-NTRK2) also underwent constitutive kinase activation. In glioblastoma-like U87MG cells, self-active TrkB kinase reduced cell migration. These constitutive signaling pathways could be fully blocked within minutes by clinically approved, anti-tumorigenic Trk inhibitors. Moreover, this study found evidences for constitutively active, intracellular TrkB in tissue of human grade IV glioblastoma. In conclusion, the data provide an explanation and biological function for selfactive, constitutive TrkB kinase domain signaling, in the absence of a ligand.},
  language  = {en}
}
@phdthesis{KimbadiLombe2021,
  author    = {Kimbadi Lombe, Blaise},
  title     = {Novel-Type Dimeric Naphthylisoquinoline Alkaloids from Congolese Ancistrocladus Lianas: Isolation, Structural Elucidation, and Antiprotozoal and Anti-Tumoral Activities},
  doi       = {10.25972/OPUS-19178},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191789},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Herein described is the discovery of three novel types of dimeric naphthylisoquinoline alkaloids, named mbandakamines, cyclombandakamines, and spirombandakamines. They were found in the leaves of a botanically as yet unidentified, potentially new Ancistrocladus species, collected in the rainforest of the Democratic Republic of the Congo (DRC). Mbandakamines showed an exceptional 6′,1′′-coupling, in the peri-position neighboring one of the outer axes, leading to an extremely high steric hindrance at the central axis, and to U-turn-like molecular shape, which - different from all other dimeric NIQs, whose basic structures are all quite linear - brings three of the four bicyclic ring systems in close proximity to each other. This created an unprecedented follow-up chemistry, involving ring closure reactions, leading to two further, structurally even more intriguing subclasses, the cyclo- and the spirombandakamines, displaying eight stereogenic elements (the highest total number ever found in naphthylisoquinoline alkaloids). The metabolites exhibited pronounced antiplasmodial and antitrypanosomal activities. Likewise reported in this doctoral thesis are the isolation and structural elucidation of naphthylisoquinoline alkaloids from two further potentially new Ancistrocladus species from DRC. Some of these metabolites have shown pronounced antiausterity activities against human pancreatic cancer PANC-1 cells.},
  subject      = {Naphthylisochinolinalkaloide},
  language  = {en}
}
@phdthesis{LindenbergverhSchubert2021,
  author    = {Lindenberg [verh. Schubert], Annekathrin},
  title     = {Timing of sensory preferences in \(Camponotus\) Ants},
  doi       = {10.25972/OPUS-16094},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-160948},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Ants belong to the most successful insects living on our planet earth. One criterion of their tremendous success is the division of labor among workers that can be related to age (age¬- or temporal polyethism) and/ or body size (size-related polymorphism). Young ants care for the queen and brood in the nest interior and switch to foraging tasks in the outside environment with ongoing age. This highly flexible interior-exterior transition probably allows the ant workers to properly match the colony needs and is one of the most impressive behaviors a single worker undergoes during its life. As environmental stimuli are changing with this transition, workers are required to perform a new behavioral repertoire. This requires significant adaptions in sensory and higher¬-order integration centers in the brain, like the mushroom bodies. Furthermore, foragers need proper time measuring mechanisms to cope with daily environmental changes and to adapt their own mode of life. Therefore, they possess a functional endogenous clock that generates rhythms with a period length of approximately 24 hours. The species-rich genus of Camponotus ants constitute a rewarding model to study how behavioral duties of division of labor were performed and modulated within the colony and how synaptic plasticity in the brain is processed, as they can divide their labor to both, age and body size, simultaneously. In my PhD thesis, I started to investigate the behavioral repertoire (like foraging and locomotor activity) of two sympatric Camponotus species, C. mus and C. rufipes workers under natural and under controlled conditions. Furthermore, I focused on the division of labor in C. rufipes workers and started to examine structural and ultrastructural changes of neuronal architectures in the brain that are accompanied by the interior-exterior transition of C. rufipes ants. In the first part of my thesis, I started to analyze the temporal organization of task allocation throughout the life of single C. rufipes workers. Constant video-tracking of individually labeled workers for up to 11 weeks, revealed an age-related division of labor of interior and exterior workers. After emergence, young individuals are tended to by older ones within the first 48 hours of their lives before they themselves start nurturing larvae and pupae. Around 52\% switch to foraging duties at an age of 14-20 days. The workers that switched to foraging tasks are mainly media-sized workers and seem to be more specialized than nurses. Variations in proportion and the age of switching workers between and within different subcolonies indicate how highly flexible and plastic the age-related division of labor occurs in this ant species. Most of the observed workers were engaged in foraging tasks exclusively during nighttime. As the experiments were conducted in the laboratory, they are completely lacking environmental stimuli of the ants´ natural habitat. I therefore asked in a second study, how workers of the two closely related Camponotus species, C. rufipes and C. mus, adapt their daily activity patterns (foraging and locomotor activity) under natural (in Uruguay, South America) and controlled (in the laboratory) conditions to changing thermal conditions. Monitoring the foraging activity of both Camponotus species in a field experiment revealed, that C. mus workers are exclusively diurnal, whereas C. rufipes foragers are predominantly nocturnal. However, some nests showed an elevated daytime activity, which could be an adaption to seasonally cold night temperatures. To further investigate the impact of temperature and light on the differing foraging activity patterns in the field, workers of both Camponotus species were artificially exposed to different thermal regimes in the laboratory, simulating local winter and summer conditions. Here again, C. mus workers display solely diurnal locomotor activity, whereas workers of C. rufipes shifted their locomotor activity from diurnal under thermal winter conditions to nocturnal under thermal summer conditions. Hence, the combination of both, field work and laboratory studies, shows that daily activity is mostly shaped by thermal conditions and that temperature cycles are not just limiting foraging activity but can be used as zeitgeber to schedule the outside activities of the nests. Once an individual worker switches from indoor duties to exterior foraging tasks, it is confronted with an entirely new set of sensory information. To cope with changes of the environmental conditions and to facilitate the behavioral switch, workers need a highly flexible and plastic neuronal system. Hence, my thesis further focuses on the underlying neuronal adaptations of the visual system, including the optic lobes as the primary visual neuropil and the mushroom bodies as secondary visual brain neuropil, that are accompanied with the behavioral switch from nursing to foraging. The optic lobes as well as the mushroom bodies of light-deprived workers show an `experience-independent´ volume increase during the first two weeks of adulthood. An additional light exposure for 4 days induces an `experience-dependent´ decrease of synaptic complexes in the mushroom body collar, followed by an increase after extended light exposure for 14 days. I therefore conclude, that the plasticity of the central visual system represents important components for the optimal timing of the interior-exterior transitions and flexibility of the age-related division of labor. These remarkable structural changes of synaptic complexes suggest an active involvement of the mushroom body neuropil in the lifetime plasticity that promotes the interior-exterior transition of Camponotus rufipes ants. Beside these investigations of neuronal plasticity of synaptic complexes in the mushroom bodies on a structural level, I further started to examine mushroom body synaptic structures at the ultrastructural level. Until recently, the detection of synaptic components in projection neuron axonal boutons were below resolution using classical Transmission Electron Microscopy. Therefore, I started to implement Electron Tomography to increase the synaptic resolution to understand architectural changes in neuronal plasticity process. By acquiring double tilt series and consecutive computation of the acquired tilt information, I am now able to resolve individual clear-core and dense-core vesicles within the projection neuron cytoplasm of C. rufipes ants. I additionally was able to reveal single postsynaptic Kenyon cell dendritic spines (~62) that surround one individual projection neuron bouton. With this, I could reveal first insights into the complex neuronal architecture of single projection neuron boutons in the olfactory mushroom body lip region. The high resolution images of synaptic architectures at the ultrastructural level, received with Electron Tomography would promote the understanding of architectural changes in neuronal plasticity. In my PhD thesis, I demonstrate that the temporal organization within Camponotus colonies involves the perfect timing of different tasks. Temperature seems to be the most scheduling abiotic factors of foraging and locomotor activity. The ants do not only need to adapt their behavioral repertoire in accordance to the interior-exterior switch, also the parts in the peripheral and central that process visual information need to adapt to the new sensory environment.},
  subject      = {Rossameise},
  language  = {en}
}
@phdthesis{Jessen2021,
  author    = {Jessen, Christina},
  title     = {NRF2 links antioxidant and immune-relevant features in melanoma},
  doi       = {10.25972/OPUS-23349},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233495},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The transcription factor NRF2 is considered as the master regulator of cytoprotective and ROS-detoxifying gene expression. Due to their vulnerability to accumulating reactive oxygen species, melanomas are dependent on an efficient oxidative stress response, but to what extent melanomas rely on NRF2 is only scarcely investigated so far. In tumor entities harboring activating mutations of NRF2, such as lung adenocarcinoma, NRF2 activation is closely connected to therapy resistance. In melanoma, activating mutations are rare and triggers and effectors of NRF2 are less well characterized. This work revealed that NRF2 is activated by oncogenic signaling, cytokines and pro-oxidant triggers, released cell-autonomously or by the tumor microenvironment. Moreover, silencing of NRF2 significantly reduced melanoma cell proliferation and repressed well-known NRF2 target genes, indicating basal transcriptional activity of NRF2 in melanoma. Transcriptomic analysis showed a large set of deregulated gene sets, besides the well-known antioxidant effectors. NRF2 suppressed the activity of MITF, a marker for the melanocyte lineage, and induced expression of epidermal growth factor receptor (EGFR), thereby stabilizing the dedifferentiated melanoma phenotype and limiting pigmentation markers and melanoma-associated antigens. In general, the dedifferentiated melanoma phenotype is associated with a reduced tumor immunogenicity. Furthermore, stress-inducible cyclooxygenase 2 (COX2) expression, a crucial immune-modulating gene, was regulated by NRF2 in an ATF4-dependent manner. Only in presence of both transcription factors was COX2 robustly induced by H2O2 or TNFα. COX2 catalyzes the first step of the prostaglandin E2 (PGE2) synthesis, which was described to be associated with tumor immune evasion and reduction of the innate immune response. In accordance with these potentially immune-suppressive features, immunocompetent mice injected with NRF2 knockout melanoma cells had a strikingly longer tumor-free survival compared to NRF2-proficient cells. In line with the in vitro data, NRF2-deficient tumors showed suppression of COX2 and induction of MITF. Furthermore, transcriptomic analyses of available tumors revealed a strong induction of genes belonging to the innate immune response, such as RSAD2 and IFIH1. The expression of these genes strongly correlated with immune evasion parameters in human melanoma datasets and NRF2 activation or PGE2 supplementation limited the innate immune response in vitro. In summary, the stress dependent NRF2 activation stabilizes the dedifferentiated melanoma phenotype and facilitates the synthesis of PGE2. As a result, NRF2 reduces gene expression of the innate immune response and promotes the generation of an immune-cold tumor microenvironment. Therefore, NRF2 not only elevated the ROS resilience, but also strongly contributed to tumor growth, maintenance, and immune control in cutaneous melanoma.},
  subject      = {Melanom},
  language  = {en}
}
@phdthesis{Heydarian2021,
  author    = {Heydarian, Motaharehsadat},
  title     = {Development of human 3D tissue models for studying \(Neisseria\) \(gonorrhoeae\) infection},
  doi       = {10.25972/OPUS-20496},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204967},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Gonorrhea is the second most common sexually transmitted infection worldwide and is caused by Gram-negative, human-specific diplococcus Neisseria gonorrhoeae. It colonizes the mucosal surface of the female reproductive tract and the male urethra. A rapid increase in antibiotic resistance makes gonorrhea a serious threat to public health worldwide. Since N. gonorrhoeae is a human-specific pathogen, animal infection models are not able to recapitulate all the features of infection. Therefore, a realistic in vitro cell culture model is urgently required for studying the gonorrhea infection. In this study, we established and characterized three independent 3D tissue models based on the porcine small intestinal submucosa (SIS) scaffold by co-culturing human dermal fibroblasts with human colorectal carcinoma, endometrial epithelial, and male uroepithelial cells. The histological, immunohistochemical, and ultra-structural analysis showed that the 3D SIS scaffold-based models closely mimic the main characteristics of the site of gonococcal infection in the human host including the formation of epithelial monolayer, underlying connective tissue, mucus production, tight junction (TJ), and microvilli. In addition, functional analysis such as transepithelial electrical resistance (TEER) and barrier permeability indicated high barrier integrity of the cell layer. We infected the established 3D tissue models with different N. gonorrhoeae strains and derivatives presenting various phenotypes regarding adhesion and invasion. The results showed disruption of TJs and growing the interleukins production in response to the infection, which depends on the type of strain and cell. In addition, the 3D tissue models supported bacterial survival, which provided an appropriate in vitro model for long-term infection study. This could be mainly because of the high resilience of the 3D tissue models based on the SIS scaffold to the infection in terms of alteration in permeability, cell destruction, and bacterial transmigration. During gonorrhea infection, a high level of neutrophils migrates to the site of infection. The studies also showed that N. gonorrhoeae can survive or even replicate inside the neutrophils. Therefore, studying the interaction between neutrophils and N. gonorrhoeae is substantially under scrutiny. For this purpose, we generated a 3D tissue model by triple co-culturing of human primary fibroblast cells, human colorectal carcinoma cells, and human umbilical vein endothelial cells. The tissue model was subsequently infected by N. gonorrhoeae. A perfusion-based bioreactor system was employed to recreate blood flow in the side of endothelial cells and consequently study human neutrophils transmigration to the site of infection. We observed neutrophils activation upon the infection. Furthermore, we demonstrated the uptake of N. gonorrhoeae by human neutrophils and reverse transmigration of neutrophils to the basal side carrying N. gonorrhoeae. In summary, the introduced 3D tissue models in this research represent a promising tool to investigate N. gonorrhoeae infections under close-to-natural conditions.},
  subject      = {3D-Gewebemodell},
  language  = {en}
}
@phdthesis{Ruedenauer2021,
  author    = {R{\"u}denauer, Fabian},
  title     = {Nutrition facts of pollen: nutritional quality and how it affects reception and perception in bees},
  doi       = {10.25972/OPUS-21254},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212548},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Nutrients belong to the key elements enabling life and influencing an organism's fitness. The intake of nutrients in the right amounts and ratios can increase fitness; strong deviations from the optimal intake target can decrease fitness. Hence, the ability to assess the nutritional profile of food would benefit animals. To achieve this, they need the according nutrient receptors, the ability to interpret the receptor information via perceptive mechanisms, and the ability to adjust their foraging behavior accordingly. Additionally, eventually existing correlations between the nutrient groups and single nutrient compounds in food could help them to achieve this adjustment. A prominent interaction between food and consumer is the interaction between flowering plants (angiosperms) and animal pollinators. Usually both of the interacting partners benefit from this mutualistic interaction. Plants are pollinated while pollinators get a (most of the times) nutritional reward in form of nectar and/or pollen. As similar interactions between plants and animals seem to have existed even before the emergence of angiosperms, these interactions between insects and angiosperms very likely have co-evolved right from their evolutionary origin. Therefore, insect pollinators with the ability to assess the nutritional profile may have shaped the nutritional profile of plant species depending on them for their reproduction via selection pressure. In Chapter I of this thesis the pollen nutritional profile of many plant species was analyzed in the context of their phylogeny and their dependence on insect pollinators. In addition, correlations between the nutrients were investigated. While the impact of phylogeny on the pollen protein content was little, the mutual outcome of both of the studies included in this chapter is that protein content of pollen is mostly influenced by the plant's dependence on insect pollinators. Several correlations found between nutrients within and between the nutrient groups could additionally help the pollinators to assess the nutrient profile of pollen. An important prerequisite for this assessment would be that the pollinators are able to differentiate between pollen of different plant species. Therefore, in Chapter II it was investigated whether bees have this ability. Specifically, it was investigated whether honeybees are able to differentiate between pollen of two different, but closely related plant species and whether bumblebees prefer one out of three pollen mixes, when they were fed with only one of them as larvae. Honeybees indeed were able to differentiate between the pollen species and bumblebees preferred one of the pollen mixes to the pollen mix they were fed as larvae, possibly due to its nutritional content. Therefore, the basis for pollen nutrient assessment is given in bees. However, there also was a slight preference for the pollen fed as larvae compared to another non-preferred pollen mix, at least hinting at the retention of larval memory in adult bumblebees. Chapter III looks into nutrient perception of bumblebees more in detail. Here it was shown that they are principally able to perceive amino acids and differentiate between them as well as different concentrations of the same amino acid. However, they do not seem to be able to assess the amino acid content in pollen or do not focus on it, but instead seem to focus on fatty acids, for which they could not only perceive concentration differences, but also were able to differentiate between. These findings were supported by feeding experiments in which the bumblebees did not prefer any of the pollen diets containing less or more amino acids but preferred pollen with less fatty acids. In no choice feeding experiments, bumblebees receiving a diet with high fatty acid content accepted undereating other nutrients instead of overeating fat, leading to increased mortality and the inability to reproduce. Hence, the importance of fat in pollen needs to be looked into further. In conclusion, this thesis shows that the co-evolution of flowering plants and pollinating insects could be even more pronounced than thought before. Insects do not only pressure the plants to produce high quality nectar, but also pressure those plants depending on insect pollination to produce high quality pollen. The reason could be the insects' ability to receive and perceive certain nutrients, which enables them to forage selectively leading to a higher reproductive success of plants with a pollinator-suitable nutritional pollen profile.},
  subject      = {Pollen},
  language  = {en}
}
@book{MacedoKoelliganBarbieri2021,
  author    = {Macedo, Jos{\´e} Marcos and K{\"o}lligan, Daniel and Barbieri, Pedro},
  title     = {Πολυώνυμοι - A Lexicon of the Divine Epithets in the Orphic Hymns},
  edition   = {1. Auflage},
  publisher = {W{\"u}rzburg University Press},
  address   = {W{\"u}rzburg},
  isbn      = {978-3-95826-154-9},
  doi       = {10.25972/WUP-978-3-95826-155-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220613},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  pages     = {260},
  year      = {2021},
  abstract  = {The Orphic Hymns consist of a prooemium and 87 hymns addressed to several deities in a late Orphic initiation of sorts. They were composed probably in Asia Minor during the second or third century CE. The bulk of these hymns are made up of divine epithets often linked together in chains of considerable length. The lexicon attempts to give a comprehensive account of the roughly 850 epithets, bringing together the most relevant information scattered in the scholarly literature and adding others from various sources (literary, epigraphic, lexicographic, scholia etc.) in order to provide an overview of their usage and the main details of their models.},
  subject      = {Orphica},
  language  = {en}
}
@phdthesis{DomeneMoreno2021,
  author    = {Domene Moreno, Christina},
  title     = {Beyond transfer? The acquisition of an L3 phonology by Turkish-German bilinguals},
  doi       = {10.25972/OPUS-23141},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231411},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Der Erwerb des phonologischen Systems einer Drittsprache wurde bisher vor allem vor dem Hintergrund zweier Fragen betrachtet: (a) Welche Sprache oder Sprachen werden in die Zielsprache transferiert und (b) welche Rolle spielen inner- und außersprachliche Faktoren dabei? Hier sind grunds{\"a}tzlich drei Szenarien denkbar, welche sich auch in den im Forschungsfeld vorherrschenden theoretischen Ans{\"a}tzen wiederfinden. Bei einem bilingualen Sprecher, also einem Sprecher mit zwei Hintergrundsprachen, ist erstens der ausschließliche Transfer einer der Hintergrundsprachen m{\"o}glich, wobei f{\"u}r die Vorhersage der Sprache, die am wahrscheinlichsten transferiert wird, verschiedene Parameter vorgeschlagen wurden, wie beispielsweise das typologische Verh{\"a}ltnis der Hintergrund- und Zielsprachen untereinander oder der Status einer der beiden Hintergrundsprachen als Erst- bzw. Zweitsprache. Weiterhin ist Transfer aus beiden Sprachen denkbar, bei dem ausschließlich „n{\"u}tzliche", das heißt den Zielspracherwerb unterst{\"u}tzende Strukturen transferiert werden. Drittens kann gemischter Transfer, also der Transfer verschiedener Strukturen, aus beiden Hintergrundsprachen angenommen werden, der allerdings nicht unbedingt positiv ist, sondern stattdessen von vielf{\"a}ltigen Faktoren konditioniert wird. In anderen Worten wird hier die M{\"o}glichkeit angenommen, Strukturen aus beiden Hintergrundsprachen in die Zielsprache zu transferieren. Dieser letzte Ansatz entspricht am besten den bisherigen Forschungsergebnissen des Felds: W{\"a}hrend sich bei Betrachtung verschiedener Sprachkombinationen und verschiedener (und verschiedenartiger) phonologischer Strukturen f{\"u}r sich genommen kein einheitliches Muster erkennen l{\"a}sst, wird deutlich, dass gemischter Transfer m{\"o}glich ist - dies kommt vor allem bei Studien zu graduellen phonetischen Ph{\"a}nomenen wie konkreter Vokalqualit{\"a}t oder Voice Onset Time zum Ausdruck. Bisherige Studien haben sich auf einzelne phonologische oder phonetische Ph{\"a}nomene beschr{\"a}nkt, anhand derer die entsprechenden Ans{\"a}tze {\"u}berpr{\"u}ft wurden. Bisher gibt es keine systematischen Untersuchungen mehrerer verschiedener Ph{\"a}nomene an denselben Sprechern. Da allerdings davon ausgegangen werden kann, dass phonologische Ph{\"a}nomene unterschiedliche strukturelle Eigenschaften haben, ist genau dies n{\"o}tig. Um also die Mechanismen des gleichzeitigen Transfers mehrerer Sprachen auf eine Zielsprache, und somit auch die Interaktion der Hintergrundsprachen in Multilingualen besser zu verstehen, m{\"u}ssen mehrere phonologische Strukturen an denselben Sprechergruppen und mit denselben Methoden untersucht werden. Diese Forschungsl{\"u}cke will die vorliegende Arbeit schließen. Hierf{\"u}r wurde der Erwerb des Lautsystems der Drittsprache Englisch durch t{\"u}rkisch-deutsch bilinguale Lerner untersucht. Es wurden phonologische Strukturen des Englischen zur Untersuchung ausgew{\"a}hlt, die entweder im Deutschen (aber nicht im T{\"u}rkischen), im T{\"u}rkischen (aber nicht im Deutschen), oder in keiner der beiden Hintergrundsprachen vorkommen. Diese Unterteilung sollte dazu dienen den potentiellen Einfluss der jeweiligen Hintergrundsprache auf die Zielsprache identifizieren zu k{\"o}nnen. In zwei Studien wurden jeweils die Perzeption und die Produktion der obengenannten Strukturen an t{\"u}rkisch-deutsch Bilingualen sowie an einer monolingual deutschen Kontrollgruppe getestet. Studie 1 testete junge Lerner des Englischen in den ersten Lernjahren, w{\"a}hrend Studie 2 Studierende der Englischen Sprach- und Literaturwissenschaft testete. Zus{\"a}tzlich wurden extralinguistische Faktoren und biographische Details erhoben. In den beiden Studien sollte beantwortet werden, ob sich bilinguale und monolinguale Testpersonen in der Perzeption und/oder der Produktion der Zielstrukturen unterscheiden, ob diese Unterschiede durch Transfer aus den Hintergrundsprachen zu erkl{\"a}ren sind und, falls dies nicht durchgehend der Fall ist, welche anderen strukturellen oder extralinguistischen Faktoren herangezogen werden k{\"o}nnen, um die Ergebnisse zu erkl{\"a}ren. Zudem sollte gepr{\"u}ft werden, inwieweit Perzeption und Produktion zusammenh{\"a}ngen und welchen Effekt fortschreitender Spracherwerb hat. Die Ergebnisse der beiden Studien dieser Arbeit best{\"a}tigen die Vermutung, die anhand der Kombination aus verschiedenen vorausgehenden Studien getroffen wurden: Transfer findet ausgehend von beiden Hintergrundsprachen statt, er kann positiv und negativ sein, und er wird von strukturellen Faktoren konditioniert. So zeigte sich im Vergleich ein deutlicher Einfluss - sowohl positiv wie auch negativ - des T{\"u}rkischen auf die Perzeption und Produktion des Englischen bei den bilingualen Sprechern, aber ebenso ein Einfluss des Deutschen. Weiterhin konnte der gleichzeitige Einfluss beider Hintergrundsprachen auf einzelne Strukturen belegt werden. Perzeption und Produktion stehen bei keiner der Sprechergruppen in einer direkten Korrelation, allerdings kann anhand der Ergebnisse Perzeption als einer der Faktoren angenommen werden, der einen Einfluss auf die Produktion der zielsprachlichen Struktur hat. Als weitere Faktoren konnten der Grad der Markiertheit der Struktur, ihre artikulatorische Komplexit{\"a}t sowie das Fehlen eines artikulatorischen Ankers identifiziert werden. Eine Verschiebung der Transferquellen fand zwischen den beiden Studien, also bedingt durch fortgeschrittenen Erwerb, nicht statt. Es konnte allerdings gezeigt werden, dass Nachteile, die aufgrund der Hintergrundsprachen den Sprechergruppen entstanden, in der {\"a}lteren Gruppe h{\"a}ufig ausgeglichen werden konnten. Die Erkl{\"a}rungsans{\"a}tze f{\"u}r das Autreten von CLI-Effekten waren abh{\"a}ngig von den Eigenschaften der einzelnen abgepr{\"u}ften Strukturen und konnten nicht systematisch verallgemeinert werden. Dies best{\"a}tigte die wenig einheitlichen Einzelergebnisse vorhergehender Studien f{\"u}r die Perzeption und Produktion mehrerer verschiedener phonologischer Strukturen durch dieselben Sprechergruppen. So konnten methodische oder gruppeninterne Gr{\"u}nde f{\"u}r die sich widersprechenden Ergebnisse erstmals ausgeschlossen werden. Im vorletzten Kapitel dieser Arbeit werden darauf aufbauend alternative Gr{\"u}nde f{\"u}r die Ergebnisse erarbeitet. Hierf{\"u}r wird das Konzept des komplexen verschachtelten (complex interlaced) eingef{\"u}hrt, das chaostheoretische Ans{\"a}tze mit der Annahme einer hierarchischen Bit-Struktur verbindet. Die vorliegende Arbeit tr{\"a}gt zu aktuellen Debatten im Bereich der Drittsprachforschung insofern bei, als dass sie als erste mehrere phonologische „Einheiten" (bits), also Phoneme, Allophone, Prozesse etc., an den gleichen Sprechern testet. Dadurch wurde deutlich, dass die konkrete Struktur phonologischer Systeme in den Mittelpunkt der Forschung zum Drittspracherwerb r{\"u}cken muss, damit vorhandene Muster erkennbar werden k{\"o}nnen. Zudem wird vorgeschlagen, verst{\"a}rkt auf Forschungsergebnisse und Theorien aus anderen Bereichen, wie beispielsweise dem Sprachwandel, der Variet{\"a}tenlinguistik und der Kontaktlinguistik zur{\"u}ckzugreifen, um letztendlich Forschung am Drittspracherwerb f{\"u}r den theoretischen Erkenntnisgewinn nutzbar zu machen.},
  subject      = {Englisch},
  language  = {en}
}
@phdthesis{Stetter2021,
  author    = {Stetter, Maurice},
  title     = {LC3-associated phagocytosis seals the fate of the second polar body in \(Caenorhabditis\) \(elegans\)},
  doi       = {10.25972/OPUS-23198},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231981},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {This work investigates the death and degradation of the second polar body of the nematode C. elegans in order to improve our understanding how pluripotent undifferentiated cells deal with dying cells. With the use of fluorescence microscopy this work demonstrates that both polar bodies loose membrane integrity early. The second polar body has contact to embryonic cells and gets internalized, dependent on the Rac1-ortholog CED-10. The polar body gets degraded via LC3-associated phagocytosis. While lysosome recruitment depends on RAB-7, LC3 does not improve lysosome recruitment but still accelerates polar body degradation. This work establishes the second polar body as a genetic model to study cell death and LC3-associated phagocytosis and has revealed further aspects of phagosome maturation and degradation.},
  subject      = {Polk{\"o}rper},
  language  = {en}
}
@phdthesis{Richter2021,
  author    = {Richter, Julian Alexander J{\"u}rgen},
  title     = {Wave-CAIPI for Accelerated Dynamic MRI of the Thorax},
  doi       = {10.25972/OPUS-23207},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232071},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {In summary, the wave-CAIPI k-space trajectory presents an efficient sampling strategy for accelerated MR acquisitions. Using wave-CAIPI in parallel imaging reconstructions leads to a reduced noise level in the reconstructed images, compared to the Cartesian standard trajectory. This effect could be quantified by means of noise and SNR calculations. An SNR gain can be traded for a reduced scan time, i.e., additional undersampling, or for an enhanced image quality, keeping scan time constant. Acceleration of MR imaging is especially important in dynamic applications, since these examinations are inherently time-consuming. The impact of wave-CAIPI sampling on image quality and its potential for scan time reduction was investigated for two dynamic applications: self-gated dynamic 3D lung MRI during free breathing and cardiac 4D flow MRI. Dynamic 3D Lung MRI By employing wave-CAIPI sampling in self-gated, free-breathing dynamic 3D lung MRI for the purpose of radiotherapy treatment planning, the image quality of accelerated scans could be enhanced. Volunteer examinations were used to quantify image quality by means of similarity between accelerated and reference images. To this end, the normalized mutual information and the root-mean-square error were chosen as quantitative image similarity measures. The wave-CAIPI sampling was shown to exhibit superior quality, especially for short scan times. The values of the normalized mutual information were (10.2 +- 7.3)\% higher in the wave-CAIPI case -- the root-mean-square error was (18.9 +- 13.2)\% lower on average. SNR calculations suggest an average SNR benefit of around 14\% for the wave-CAIPI, compared to Cartesian sampling. Resolution of the lung in 8 breathing states can be achieved in only 2 minutes. By using the wave-CAIPI k-space trajectory, precise tumor delineation and assessment of respiration-induced displacement is facilitated. Cardiac 4D Flow MRI In 4D flow MRI, acceleration of the image acquisition is essential to incorporate the corresponding scan protocols into clinical routine. In this work, a retrospective 6-fold acceleration of the image acquisition was realized. Cartesian and wave-CAIPI 4D flow examinations of healthy volunteers were used to quantify uncertainties in flow parameters for the respective sampling schemes. By employing wave-CAIPI sampling, the estimated errors in flow parameters in 6-fold accelerated scans could be reduced by up to 55\%. Noise calculations showed that the noise level in 6-fold accelerated 4D flow acquisitions with wave-CAIPI is 43\% lower, compared to Cartesian sampling. Comparisons between Cartesian and wave-CAIPI 4D flow examinations with a prospective acceleration factor R=2 revealed small, but partly statistically significant discrepancies. Differences between 2-fold and 6-fold accelerated wave-CAIPI scans are comparable to the differences between Cartesian and wave-CAIPI examinations at R=2. Wave-CAIPI 4D flow acquisitions of the aorta could be performed with an average, simulated scan time of under 4 minutes, with reduced uncertainties in flow parameters. Important visualizations of hemodynamic flow patterns in the aorta were only slightly affected by undersampling in the wave-CAIPI case, whereas for Cartesian sampling, considerable discrepancies were observed.},
  subject      = {Magnetresonanztomographie},
  language  = {en}
}
@phdthesis{Tang2021,
  author    = {Tang, Ruijing},
  title     = {Optogenetic Methods to Regulate Water Transport and Purify Proteins},
  doi       = {10.25972/OPUS-23173},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231736},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Water transport through the water channels, aquaporins (AQPs), is involved in epithelial fluid secretion and absorption, cell migration, brain edema, adipocyte metabolism, and other physiological or pathological functions. Modulation of AQP function has therapeutic potential in edema, cancer, obesity, brain injury, glaucoma, etc. The function of AQPs is in response to the osmotic gradient that is formed by the concentration differences of ions or small molecules. In terms of brain edema, it is a pathophysiological condition, resulting from dysfunction of the plasma membrane that causes a disorder of intracellular ion homeostasis and thus increases intracellular fluid content. Optogenetics can be used to regulate ion transport easily by light with temporal and spatial precision. Therefore, if we control the cell ion influx, boosting the water transport through AQPs, this will help to investigate the pathological mechanisms in e.g. brain edema. To this end, I investigated the possibility for optogenetic manipulating water transport in Xenopus oocytes. The main ions in Xenopus oocyte cytoplasm are ~10 mM Na+, ~50 mM Cl- and ~100 mM K+, similar to the mammalian cell physiological condition. Three light-gated channels, ChR2-XXM 2.0 (light-gated cation channel), GtACR1 (light-gated anion channel) and SthK-bPAC (light-gated potassium channel), were used in my study to regulate ion transport by light and thus manipulate the osmotic gradient and water transport. To increase water flow, I also used coexpression of AQP1. When expressing ChR2-XXM 2.0 and GtACR1 together, mainly Na+ influx was triggered by ChR2-XXM2.0 under blue light illumination, which then made the membrane potential more positive and facilitated Cl- influx by GtACR1. Due to this inward movement of Na+ and Cl-, the osmotic gradient was formed to trigger water influx through AQP1. Large amounts of water uptake can speedily increase the oocyte volume until membrane rupture. Next, when co-expressing GtACR1 and SthK-bPAC, water efflux will be triggered with blue light because of the light-gated KCl efflux and then oocyte shrinking could be observed. I also developed an optogenetic protein purification method based on a light-induced protein interactive system. Currently, the most common protein purification method is based on affinity chromatography, which requires different chromatography columns and harsh conditions, such as acidic pH 4.5 - 6 and/or adding imidazole or high salt concentration, to elute and collect the purified proteins. The change in conditions could influence the activity of target proteins. So, an easy and flexible protein purification method based on the photo-induced protein interactive system iLID was designed, which regulates protein binding with light in mild conditions and does not require a change of solution composition. For expression in E. coli, the blue light-sensitive part of iLID, the LOV2 domain, was fused with a membrane anchor and expressed in the plasma membrane, and the other binding partner, SspB, was fused with the protein of interest (POI), expressed in the cytosol. The plasma membrane fraction and the soluble cytosolic fraction of E. coli can be easily separated by centrifugation. The SspB-POI can be then captured to the membrane fraction by light stimulation and released to clean buffer in the dark after washing. This method does not require any specific column and functions in mild conditions, which are very flexible at scale and will facilitate extensive protein engineering and purification of proteins, sensitive to changed buffer conditions.},
  language  = {en}
}
@phdthesis{Jetani2021,
  author    = {Jetani, Hardikkumar},
  title     = {Chimeric antigen receptor (CAR)-modified T cells targeting FLT3 in acute myeloid leukemia (AML)},
  doi       = {10.25972/OPUS-17909},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179096},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Adoptive immunotherapy using chimeric antigen receptor (CAR)-modified T cells targeting CD19 has shown remarkable therapeutic efficacy against B cell leukemia and lymphoma, and provided proof of concept for therapeutic potential in other hematologic malignancies. Acute myeloid leukemia (AML) is an entity with an unmet medical need for effective and curative treatments. Therefore, there is a strong desire for development of potentially curative CAR-T cell immunotherapy for AML treatment. FMS-like tyrosine kinase 3 (FLT3) is a homodimeric transmembrane protein expressed uniformly by AML blasts. FLT3 plays a vital role in the survival of AML blasts and is a key driver of leukemia-genesis in AML cases with internal tandem duplication (FLT3ITD) and tyrosine kinase domain (TKD) mutations. These attributes suggest that FLT3 could be an excellent target for CAR-T cell immunotherapy. Here, we engineered human CD4+ and CD8+ T cells to express FLT3-specific CARs and demonstrate that they confer potent reactivity against AML cell lines and primary AML blasts that express either wild-type FLT3 or FLT3-ITD. Further, we show that FLT3 CAR-T cells exert potent antileukemia activity in xenograft models of AML and induce complete remissions. We also demonstrate that FLT3-expression on FLT3-ITD+ AML cells can be augmented by FLT3 inhibitors, which lead to increased recognition by CARs and improved efficacy of FLT3 CAR-T cells. We confirmed this principle with three different FLT3 inhibitors which are at distinct stages of clinical development i.e. Phase II/III clinical trial (crenolanib, quizartinib) and clinically approved (midostaurin). Further, we observed the strongest anti-leukemia activity of FLT3 CAR-T cells in combination with crenolanib in vivo. FLT3 is known to be expressed by normal hematopoietic stem and progenitor cells. We evaluated FLT3-expression on normal hematopoietic stem cells (HSCs) using flow cytometry and confirmed lower level of FLT3-expression on HSCs and progenitors compared to AML cells. As anticipated, we found that FLT3 CAR-T cells recognize normal HSCs in vitro and in vivo, and compromise normal hematopoiesis, suggesting that adoptive therapy with FLT3 CAR-T cells will require successive CAR-T cell depletion and allogeneic HSC transplantation (HSCT) to reconstitute the hematopoietic system. Moreover, an FLT3 inhibitor treatment does not increase FLT3-expression on HSCs. Accordingly, we demonstrate that the depletion of FLT3 CAR-T cells is possible with inducible Caspase 9 (iCasp9) safety switch. Collectively, our data establish FLT3 as a novel CAR target in AML with particular relevance in high-risk FLT3-ITD+ AML. Our data demonstrate that FLT3 CAR-T cells act synergistically with FLT3 inhibitors in FLT3-ITD+ AML. i.e. FLT3 inhibitors-induced upregulation of FLT3 in FLT3-ITD+ AML cells enhances their recognition and elimination by FLT3 CAR-T cells. Due to recognition of normal HSCs, the clinical use of FLT3 CART cells is likely restricted to a defined therapeutic window and must be followed by CART cell depletion and allogeneic HSCT for hematopoietic reconstitution. The data provide rational to use FLT3 CAR-T cells in combination with FLT3 inhibitors to augment the anti-leukemia efficacy of FLT3 CAR-T cells in high-risk FLT3-ITD+ AML patients, and to mitigate the risk of relapse with FLT3-negative AML variants, which could otherwise develop under therapeutic pressure. The data provide proof of concept for synergistic use of CAR-T cell immunotherapy and small molecule targeted therapy and encourage the clinical evaluation of this combination treatment in high-risk patients with FLT3-ITD+ AML.},
  subject      = {Chimeric antigen receptor (CAR)},
  language  = {en}
}
@phdthesis{Auer2021,
  author    = {Auer, Daniela},
  title     = {Impact of the chlamydial deubiquitinase ChlaDUB1 on host cell defense},
  doi       = {10.25972/OPUS-17846},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178462},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The human pathogen Chlamydia trachomatis is the main cause of sexually transmitted infections worldwide. The obligate intracellular bacteria are the causative agent of several diseases that reach from conjunctivitis causing trachoma and blindness as well as salpingitis and urethritis which can lead to infertility if left untreated. In order to gain genetically engineered Chlamydia that inducible knock down specific gene expression, the CRISPRi system was established in C. trachomatis. In a proof of principle experiment it was shown that C. trachomatis pCRISPRi:gCdu1III target ChlaDUB1 expression and reduce the protein amount up to 50 \%. Knock-down of the DUB did not influence protein levels of anti-apoptotic Mcl-1 and did not make cells susceptible for apoptosis. However, reduced dCas9 protein size, bacterial growth impairment and off target effects interfering with the GFP signal, form obstacles in CRISPRi system in Chlamydia. For routinely use of the CRISPRi method in C. trachomatis further investigation is needed. Since the bacterial life cycle includes two morphological and functional distinct forms, it is essential for chlamydial spread to complete the development cycle and form infectious progeny. Therefore, Chlamydia has evolved strategies to evade the host immune system in order to stay undetected throughout the developmental cycle. The bacteria prevent host cell apoptosis via stabilization of anti-apoptotic proteins like Mcl-1, Survivin and HIF-1α and activate pro-survival pathways, inhibiting invasion of immune cells to the site of infection. The host cell itself can destroy intruders via cell specific defense systems that involve autophagy and recruitment of professional immune cells. In this thesis the role of the chlamydial deubiuqitinase ChlaDUB1 upon immune evasion was elucidated. With the mutant strain Ctr Tn-cdu1 that encodes for a truncated DUB due to transposon insertion, it was possible to identify ChlaDUB1 as a potent opponent of the autophagic system. Mutant inclusions were targeted by K48 and K63 chain ubiquitination. Subsequently the inclusion was recognized by autophagic receptors like p62, NBR1 and NDP52 that was reversed again by complementation with the active DUB. Xenophagy was promoted so far as LC3 positive phagosomes formed around the inclusion of Ctr Tn-cdu1, which did not fuse with the lysosome. The detected growth defect in human primary cells of Chlamydia missing the active DUB was not traced back to autophagy, but was due to impaired development and replication. It was possible to identify Ankib1, the E3 ligase, that ubiquitinates the chlamydial inclusion in a siRNA based screen. The activating enzyme Ube1 and the conjugating enzyme Ube2L3 are also essential in this process. Chlamydia have a reduced genome and depend on lipids and nutrients that are translocated from the host cell to the inclusion to proliferate. Recruitment of fragmented Golgi stacks to the inclusion surface was prevented when ChlaDUB1 was inactive, probably causing diminished bacterial growth. Additionally, the modification of the inclusion by Ankib1 and subsequent decoration by autophagic markers was not only present in human but also murine cells. Comparison of other Chlamydia strains and species revealed Ankib1 to be located at the proximity of the inclusion in C. trachomatis strains only but not in C. muridarum or C. pneumoniae, indicating that Ankib1 is specifically the E3 ligase of C. trachomatis. Moreover, the role of ChlaDUB1 in infected tissue was of interest, since ChlaDUB1 protein was also found in early EB stage and so might get in contact with invading immune cells after cell lysis. While bacteria spread and infect new host cells, Chlamydia can also infect immune cells. Infection of human neutrophils with Ctr Tn-cdu1 shows less bacterial survival and affirms the importance of the DUB for bacterial fitness in these cells.},
  subject      = {Chlamydia},
  language  = {en}
}
@phdthesis{Ullherr2021,
  author    = {Ullherr, Maximilian},
  title     = {Optimization of Image Quality in High-Resolution X-Ray Imaging},
  doi       = {10.25972/OPUS-23117},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231171},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The SNR spectra model and measurement method developed in this work yield reliable application-specific optima for image quality. This optimization can either be used to understand image quality, find out how to build a good imaging device or to (automatically) optimize the parameters of an existing setup. SNR spectra are here defined as a fraction of power spectra instead of a product of device properties. In combination with the newly developed measurement method for this definition, a close correspondence be- tween theory and measurement is achieved. Prior approaches suffer from a focus on theoretical definitions without fully considering if the defined quantities can be measured correctly. Additionally, discrepancies between assumptions and reality are common. The new approach is more reliable and complete, but also more difficult to evaluate and interpret. The signal power spectrum in the numerator of this fraction allows to model the image quality of different contrast mechanisms that are used in high-resolution x-ray imaging. Superposition equations derived for signal and noise enable understanding how polychromaticity (or superposition in general) affects the image quality. For the concept of detection energy weighting, a quantitative model for how it affects im- age quality was found. It was shown that—depending on sample properties—not detecting x-ray photons can increase image quality. For optimal computational energy weighting, more general formula for the optimal weight was found. In addition to the signal strength, it includes noise and modulation transfer. The novel method for measuring SNR spectra makes it possible to experimentally optimize image quality for different contrast mechanisms. This method uses one simple measurement to obtain a measure for im- age quality for a specific experimental setup. Comparable measurement methods typically require at least three more complex measurements, where the combination may then give a false result. SNR spectra measurements can be used to: • Test theoretical predictions about image quality optima. • Optimize image quality for a specific application. • Find new mechanisms to improve image quality. The last item reveals an important limitation of x- ray imaging in general: The achievable image quality is limited by the amount of x-ray photons interacting with the sample, not by the amount incident per detector area (see section 3.6). If the rest of the imaging geometry is fixed, moving the detector only changes the field of view, not the image quality. A practical consequence is that moving the sample closer to the x-ray source increases image quality quadratically. The results of a SNR spectra measurement represent the image quality only on a relative scale, but very reliable. This relative scale is sufficient for an optimization problem. Physical effects are often already clearly identifiable by the shape of the functional relationship between input parameter and measurement result. SNR spectra as a quantity are not well suited for standardization, but instead allow a reliable optimization. Not satisfying the requirements of standardization allows to use methods which have other advantages. In this case, the SNR spectra method describes the image quality for a specific application. Consequently, additional physical effects can be taken into account. Additionally, the measurement method can be used to automate the setting of optimal machine parameters. The newly proposed image quality measure detection effectiveness is better suited for standardization or setup comparison. This quantity is very similar to measures from other publications (e.g. CNR(u)), when interpreted monochromatically. Polychromatic effects can only be modeled fully by the DE(u). The measurement processes of both are different and the DE(u) is fundamentally more reliable. Information technology and digital data processing make it possible to determine SNR spectra from a mea- sured image series. This measurement process was designed from the ground up to use these technical capabilities. Often, information technology is only used to make processes easier and more exact. Here, the whole measurement method would be infeasible without it. As this example shows, using the capabilities of digital data processing much more extensively opens many new possibilities. Information technology can be used to extract information from measured data in ways that analog data processing simply cannot. The original purpose of the SNR spectra optimization theory and methods was to optimize high resolution x-ray imaging only. During the course of this work, it has become clear that some of the results of this work affect x-ray imaging in general. In the future, these results could be applied to MI and NDT x-ray imaging. Future work on the same topic will also need to consider the relationship between SNR spectra or DE(u) and sufficient image quality.This question is about the minimal image quality required for a specific measurement task.},
  subject      = {Bildqualit{\"a}t},
  language  = {en}
}