@phdthesis{Gebert2022, author = {Gebert, Friederike}, title = {Mammals and dung beetles along elevational and land use gradients on Mount Kilimanjaro: diversity, traits and ecosystem services}, doi = {10.25972/OPUS-19195}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191950}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Despite belonging to the best described patterns in ecology, the mechanisms driving biodiversity along broad-scale climatic gradients, like the latitudinal gradient in diversity, remain poorly understood. Because of their high biodiversity, restricted spatial ranges, the continuous change in abiotic factors with altitude and their worldwide occurrence, mountains constitute ideal study systems to elucidate the predictors of global biodiversity patterns. However, mountain ecosystems are increasingly threatened by human land use and climate change. Since the consequences of such alterations on mountainous biodiversity and related ecosystem services are hardly known, research along elevational gradients is also of utmost importance from a conservation point of view. In addition to classical biodiversity research focusing on taxonomy, the significance of studying functional traits and their prominence in biodiversity ecosystem functioning (BEF) relationships is increasingly acknowledged. In this dissertation, I explore the patterns and drivers of mammal and dung beetle diversity along elevational and land use gradients on Mt. Kilimanjaro, Tanzania. Furthermore, I investigate the predictors of dung decomposition by dung beetles under different extinction scenarios. Mammals are not only charismatic, they also fulfil important roles in ecosystems. They provide important ecosystem services such as seed dispersal and nutrient cycling by turning over high amounts of biomass. In chapter II, I show that mammal diversity and community biomass both exhibited a unimodal distribution with elevation on Mt.Kilimanjaro and were mainly impacted by primary productivity, a measure of the total food abundance, and the protection status of study plots. Due to their large size and endothermy, mammals, in contrast to most arthopods, are theoretically predicted to be limited by food availability. My results are in concordance with this prediction. The significantly higher diversity and biomass in the Kilimanjaro National Park and in other conservation areas underscore the important role of habitat protection is vital for the conservation of large mammal biodiversity on tropical mountains. Dung beetles are dependent on mammals since they rely upon mammalian dung as a food and nesting resource. Dung beetles are also important ecosystem service providers: they play an important role in nutrient cycling, bioturbation, secondary seed dispersal and parasite suppression. In chapter III, I show that dung beetle diversity declined with elevation while dung beetle abundance followed a hump-shaped pattern along the elevational gradient. In contrast to mammals, dung beetle diversity was primarily predicted by temperature. Despite my attempt to accurately quantifiy mammalian dung resources by calculating mammalian defecation rates, I did not find an influence of dung resource availability on dung beetle richness. Instead, higher temperature translated into higher dung beetle diversity. Apart from being important ecosystem service providers, dung beetles are also model organisms for BEF studies since they rely on a resource which can be quantified easily. In chapter IV, I explore dung decomposition by dung beetles along the elevational gradient by means of an exclosure experiment in the presence of the whole dung beetle community, in the absence of large dung beetles and without any dung beetles. I show that dung decomposition was the highest when the dung could be decomposed by the whole dung beetle community, while dung decomposition was significantly reduced in the sole presence of small dung beetles and the lowest in the absence of dung beetles. Furthermore, I demonstrate that the drivers of dung decomposition were depend on the intactness of the dung beetle community. While body size was the most important driver in the presence of the whole dung beetle community, species richness gained in importance when large dung beetles were excluded. In the most perturbed state of the system with no dung beetles present, temperature was the sole driver of dung decomposition. In conclusion, abiotic drivers become more important predictors of ecosystem services the more the study system is disturbed. In this dissertation, I exemplify that the drivers of diversity along broad-scale climatic gradients on Mt. Kilimanjaro depend on the thermoregulatory strategy of organisms. While mammal diversity was mainly impacted by food/energy resources, dung beetle diversity was mainly limited by temperature. I also demonstrate the importance of protected areas for the preservation of large mammal biodiversity. Furthermore, I show that large dung beetles were disproportionately important for dung decomposition as dung decomposition significantly decreased when large dung beetles were excluded. As regards land use, I did not detect an overall effect on dung beetle and mammal diversity nor on dung beetle-mediated dung decomposition. However, for the most specialised mammal trophic guilds and dung beetle functional groups, negative land use effects were already visible. Even though the current moderate levels of land use on Mt. Kilimanjaro can sustain high levels of biodiversity, the pressure of the human population on Mt. Kilimanjaro is increasing and further land use intensification poses a great threat to biodiversity. In synergy wih land use, climate change is jeopardizing current patterns and levels of biodiversity with the potential to displace communities, which may have unpredictable consequences for ecosystem service provisioning in the future.}, subject = {Kilimandscharo}, language = {en} } @phdthesis{Lewerentz2022, author = {Lewerentz, Anne F.}, title = {Spatiotemporal dynamics of freshwater macrophytes in Bavarian lakes under environmental change}, doi = {10.25972/OPUS-28770}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287700}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Macrophytes are key components of freshwater ecosystems because they provide habitat, food, and improve the water quality. Macrophyte are vulnerable to environmental change as their physiological processes depend on changing environmental factors, which themselves vary within a geographical region and along lake depth. Their spatial distribution is not well understood and their importance is publicly little-known. In this thesis, I have investigated the spatiotemporal dynamics of freshwater macrophytes in Bavarian lakes to understand their diversity pattern along different scales and to predict and communicate potential consequences of global change on their richness. In the introduction (Chapter 1), I provide an overview of the current scientific knowledge of the species richness patterns of macrophytes in freshwater lakes, the influences of climate and land-use change on macrophyte growth, and different modelling approaches of macrophytes. The main part of the thesis starts with a study about submerged and emergent macrophyte species richness in natural and artificial lakes of Bavaria (Chapter 2). By analysing publicly available monitoring data, I have found a higher species richness of submerged macrophytes in natural lakes than in artificial lakes. Furthermore, I showed that the richness of submerged species is better explained by physio-chemical lake parameters than the richness of emergent species. In Chapter 3, I considered that submerged macrophytes grow along a depth gradient that provides a sharp environmental gradient on a short spatial scale. This study is the first comparative assessment of the depth diversity gradient (DDG) of macrophytes. I have found a hump-shaped pattern of different diversity components. Generalised additive mixed-effect models indicate that the shape of the DDG is influenced mainly by light quality, light quantity, layering depth, and lake area. I could not identify a general trend of the DDG within recent years, but single lakes show trends leading into different directions. In Chapter 4, I used a mechanistic eco-physiological model to explore changes in the distribution of macrophyte species richness under different scenarios of environmental conditions across lakes and with depths. I could replicate the hump-shaped pattern of potential species richness along depth. Rising temperature leads to increased species richness in all lake types, and depths. The effect of turbidity and nutrient change depends on depth and lake type. Traits that characterise "loser species" under increased turbidity and nutrients are a high light consumption and a high sensibility to disturbances. "Winner species" can be identified by a high biomass production. In Chapter 5, I discuss the image problem of macrophytes. Unawareness, ignorance, and the poor accessibility of macrophytes can lead to conflicts of use. I assumed that an increased engagement and education could counteract this. Because computer games can transfer knowledge interactively while creating an immersive experience, I present in the chapter an interactive single-player game for children. Finally, I discuss the findings of this thesis in the light of their implications for ecological theory, their implications for conservation, and future research ideas (Chapter 6). The findings help to understand the regional distribution and the drivers of macrophyte species richness. By applying eco-physiological models, multiple environmental shaping factors for species richness were tested and scenarios of climate and land-use change were explored.}, subject = {{\"O}kologie}, language = {en} } @article{HelmerHottenrottSteinischetal.2022, author = {Helmer, Philipp and Hottenrott, Sebastian and Steinisch, Andreas and R{\"o}der, Daniel and Schubert, J{\"o}rg and Steigerwald, Udo and Choorapoikayil, Suma and Meybohm, Patrick}, title = {Avoidable blood loss in critical care and patient blood management: scoping review of diagnostic blood loss}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {2}, issn = {2077-0383}, doi = {10.3390/jcm11020320}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255145}, year = {2022}, abstract = {Background: Anemia remains one of the most common comorbidities in intensive care patients worldwide. The cause of anemia is often multifactorial and triggered by underlying disease, comorbidities, and iatrogenic factors, such as diagnostic phlebotomies. As anemia is associated with a worse outcome, especially in intensive care patients, unnecessary iatrogenic blood loss must be avoided. Therefore, this scoping review addresses the amount of blood loss during routine phlebotomies in adult (>17 years) intensive care patients and whether there are factors that need to be improved in terms of patient blood management (PBM). Methods: A systematic search of the Medline Database via PubMed was conducted according to PRISMA guidelines. The reported daily blood volume for diagnostics and other relevant information from eligible studies were charted. Results: A total of 2167 studies were identified in our search, of which 38 studies met the inclusion criteria (9 interventional studies and 29 observational studies). The majority of the studies were conducted in the US (37\%) and Canada (13\%). An increasing interest to reduce iatrogenic blood loss has been observed since 2015. Phlebotomized blood volume per patient per day was up to 377 mL. All interventional trials showed that the use of pediatric-sized blood collection tubes can significantly reduce the daily amount of blood drawn. Conclusion: Iatrogenic blood loss for diagnostic purposes contributes significantly to the development and exacerbation of hospital-acquired anemia. Therefore, a comprehensive PBM in intensive care is urgently needed to reduce avoidable blood loss, including blood-sparing techniques, regular advanced training, and small-volume blood collection tubes.}, language = {en} } @phdthesis{Djaković2022, author = {Djaković, Lara}, title = {The HSV-1 ICP22 protein selectively impairs histone repositioning upon Pol II transcription downstream of genes}, doi = {10.25972/OPUS-24670}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246709}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Herpes Simplex Virus type 1 (HSV-1) is an ubiquitous neurotropic human pathogen that infects a large majority of the world's population. It is the causative agent of the common cold sore but also responsible for life-threatening infections (e.g., encephalitis), particularly in immunocompromised individuals and neonates. Like other herpesviruses, HSV-1 takes over the cellular RNA machinery to facilitate productive infection while efficiently shutting down host gene expression by targeting multiple steps of RNA metabolism. The two viral proteins, vhs and ICP27, play a crucial role in this process. Delivered by the tegument of the incoming virus, the virion host shut-off (vhs) endonuclease rapidly starts cleaving both cellular and viral mRNAs. With the onset of viral gene expression, the HSV-1 immediate-early protein ICP27 promotes the expression of viral early and late genes through various mechanisms, including mRNA processing, export, and translation. Prior research by the D{\"o}lken lab demonstrated that lytic HSV-1 infection results in the disruption of transcription termination (DoTT) of most cellular genes by the viral ICP27 protein. This significantly contributes to HSV-1 induced host shut-off. DoTT results in transcription for tens of thousands of nucleotides beyond poly(A) sites and into downstream genes. Interestingly, this was found to be accompanied by a dramatic increase in chromatin accessibility downstream of the affected poly(A) sites. This is consistent with the formation of extensive downstream open chromatin regions (dOCR) and indicative of impaired histone repositioning in the wake of RNA polymerase II (Pol II) downstream of the affected poly(A) sites. In my PhD thesis, I demonstrate that dOCR formation is dependent on the viral ICP22 protein when poly(A) read-through transcription is triggered by the ectopic expression of ICP27 or salt stress. I show that dOCR formation occurs when a high level of transcriptional activity arises downstream of genes due to the HSV-1-induced DoTT. To investigate whether histone composition is affected downstream of genes, I established the ChIPmentation approach to study associated changes and the influence of DoTT and dOCR formation on major histone modification marks. In HSV-1 WT infection, dOCR formation was reflected in alterations of canonical H1 histone downstream of affected genes, which was absent in ICP22 infection. To elucidate the underlying molecular mechanism, two major histone chaperones SPT6 and FACT (SPT16 and SSRP1), which govern histone repositioning and may thus play a role in H1 homeostasis, were extensively studied. Both histone chaperones have been recently shown to be recruited to the viral genome by interactions with ICP22 protein. To investigate whether the depletion of SSRP1 or SPT6 would complement the loss of ICP22 to induce dOCR, T-HF cells with doxycycline-inducible knock-down of either of the two factors were generated. ATAC-seq analysis revealed that the interaction between the two histone chaperones and ICP22 is not involved in HSV-1-induced dOCR formation, suggesting the involvement of other proteins. In summary, this work sheds new light on a fundamental molecular mechanism of the cellular transcriptional machinery that is manipulated by the concerted actions of the two HSV-1 immediate-early proteins ICP22 and ICP27.}, subject = {HSV-1}, language = {en} } @phdthesis{Liesner2022, author = {Liesner, Marvin Paul}, title = {I control it, but does it mean it is part of me? How the relationship between body movements and controlled object movements influences the sense of agency and the sense of ownership}, doi = {10.25972/OPUS-28703}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287030}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The "active self" approach suggests that any object we manipulate voluntarily and foreseeably becomes part of our "self" in the sense that we feel control over this object (sense of agency) and experience it as belonging to our own body (sense of ownership). While there is considerable evidence that we can indeed experience both a sense of agency and a sense of ownership over a broad variety of objects when we control these through our actions, the approach has also been criticized for exaggerating the flexibility of the human self. In this thesis, I investigate the influence that the relationship between the body movements controlling an object and the movements of the object itself has on the process of integrating an object into the self. I demonstrate that fully controlling an object is not sufficient for it to be integrated into the self since both explicit and implicit measures of the sense of agency and the sense of ownership indicate less or no integration when body movements are transformed into inverted object movements. Furthermore, I show that such inversions lead to the downregulation of sensory signals either from the body or from the controlled object in order to deal with the conflicting multisensory information when performing such actions. I argue that this downregulation is the underlying factor behind the diminished or eliminated integration of inverted body and object movements and I discuss further pathways for possible future studies building up on these findings.}, subject = {Experimentelle Psychologie}, language = {en} } @phdthesis{Oberndorfer2022, author = {Oberndorfer, Florian}, title = {Photoluminescence and Raman spectroscopy of doped nanomaterials}, doi = {10.25972/OPUS-27854}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-278540}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {This thesis includes measurements that were recorded by cooperation partners. The EPR spec- trosa mentioned in section 5.2 were recorded by Michael Auth from the Dyakonov Group (Ex- perimental Physics VI, Julius-Maximilians-Universit{\"a}t, W{\"u}rzburg). The TREFISH experiments and transient absorption in section 5.4 spectra were performed by Jašinskas et al. from the V. Gulbi- nas group (Center for Physical Sciences and Technology, Vilnius, Lithuania). This dissertation investigated the interactions of semiconducting single-walled carbon nanotubes (SWNTs) of (6,5) chirality with their environment. Shear-mixing provided high-quality SWNT sus- pensions, which was complemented by various film preparation techniques. These techniques were in turn used to prepare heterostructures with MoS2 and hBN, which were examined with a newly constructed photoluminescence microscope specifically for this purpose. Finally, the change of spectral properties of SWNTs upon doping was investigated in more detail, as well as the behaviour of charge carriers in the tubes themselves. To optimise the SWNT sample preparation techniques that supplied the other experiments, the sample quality of shear-mixed preparations was compared with that of sonicated samples. It was found that the quantum efficiency of sheared suspensions exceeds that of sonicated suspensions as soon as the sonication time exceeds 30 min. The higher PLQY is due to the lower defect concentration in shear-mixed samples. Via transient absorption, a mean lifetime of 17.3 ps and a mean distance between defects of 192.1 nm could be determined. Furthermore, it was found that the increased efficiency of horn sonication is probably not only due to higher shear forces acting on the SWNT bundles but also that the shortening of PFO-BPy strands plays a significant role. Sonication of very long polymer strands significantly increased their effectiveness in shear mixing. While previous approaches could only achieve very low concentrations of SWNTs in suspensions, pre-sonicated polymer yielded results which were comparable with much shorter PFO-BPy batches. Reference experiments also showed that different aggregation processes are relevant during production and further processing. Initial reprocessing of carbon nanotube raw material requires 7 h sonication time and over 24 h shear mixing before no increase in carbon nano concentration is detectable. However, only a few minutes of sonication or shear mixing are required when reprocessing the residue produced during the separation of the slurry. This discrepancy indicates that different aggregates are present, with markedly different aggregation properties. To study low-dimensional heterostructures, a PL microscope was set up with the ability to ob- serve single SWNTs as well as monolayers of other low-dimensional systems. Furthermore, sam- ples were prepared which bring single SWNTs into contact with 2D materials such as h-BN andMoS2 layers and the changes in the photoluminescence spectrum were documented. For h-BN, it was observed whether previous methods for depositing SWNTs could be transferred for photo- luminescence spectroscopy. SWNTs were successfully deposited on monolayers via a modified drip coating, with the limitation that SWNTs aggregate more at the edges of the monolayers. Upon contact of SWNTs with MoS2, significant changes in the emission properties of the mono- layers were observed. The fluorescence, which was mainly dominated by excitons, was shifted towards trion emission. Reference experiments excluded PFO-BPy and toluene as potential causes. Based on the change in the emission behaviour of MoS2, the most plausible explanation is a photoinduced charge transfer leading to delocalised charge carriers on MoS2. In contrast, on SWNTs, the introduction of additional charges would constitute a quenching centre, which would quench their PL emission, making them undetectable in the PL image. In the last chapter, the electronic properties of doped SWNTs and the behaviour of charge carri- ers inside the tubes should be investigated. First, the change in the conductivity of SWNT films with increasing doping levels was docu- mented. The resistance of the films drops drastically at minimum doping. After the initial in- troduction of charges, the resistance drops with increasing dopant concentration according to a double logarithmic curve. The initial drop could be due to a reduction of contact resistances within the SWNT network film, but this could not be further investigated within the scope of this PhD thesis. In cooperation with Andreas Sperlich and Michael Auth, the spin concentration of SWNTs at different doping levels was determined. The obtained concentrations were compared with the carrier concentrations determined from PL and absorption spectra. At low spin densities, good agreement with previous models was found. Furthermore, the presence of isolated spins strongly suggests a localised charge carrier distribution at temperatures around 10 K. When the charge density is increased, the spin density deviates significantly from the charge carrier con- centration. This discrepancy is attributed to the increasing delocalisation of charge carriers at high charge densities and the interactions of neighbouring spins. These results strongly indicate the existence of localised charge carriers in SWNTs at low temperatures. Next, the effect of doping on the Raman spectra of SWNT suspensions was investigated. In gen- eral, doping is expected to reduce the intensity of the Raman bands, i.e. a consequence of the reduced resonance gain due to bleaching of the S2 transition. However, similar to the resistivity measurements, the oscillator strength of the G+ band drops sharply in the first doping steps. It was also found that the G+ band decreases more than would be expected due to loss of reso- nance condition. Furthermore, the G- is bleached faster than the G+ band. All these anomalies suggest that resonance enhancement is not the only relevant effect. Another much faster deac- tivation path for the excitons may be introduced by doping. This would leave less time for the scattering process to occur and reduce the oscillator strength of the Raman bands. In cooperation with Vidmantas et al., the photoinduced charge carrier behaviour of SWNT/PCBM films was investigated. The required films were prepared by drop coating. The SWNT suspen- sions required for this were obtained from sheared SWNT preparations. Using transient absorp- tion and TREFISH, a number of charge transfer effects were identified and their dynamics in- vestigated: the recombination of neutral excitons (< 50 ps), the electron transfer from carbon nanotubes to PCBM molecules (< 1 ps), the decay of charge-transfer excitons (∼200 ps), the recombination of charge carriers between charge-transfer excitons (1 ns to 4 ns) and finally the propagation through the SWNT network (∼20 ns)}, subject = {Einwandige Kohlenstoff-Nanor{\"o}hre}, language = {en} } @phdthesis{Merz2022, author = {Merz, Viktor}, title = {Funktionalisierung und Untersuchung von Nanodiamanten f{\"u}r biomedizinische und sensorische Anwendungen}, doi = {10.25972/OPUS-24588}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245888}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Nanodiamant (ND) ist ein vielseitiges und vielversprechendes Material f{\"u}r Bio-Anwendungen. Trotz vieler Bem{\"u}hungen bleibt die Agglomeration von Nanodiamant und die unspezifische Adsorption von Proteinen an der ND-Oberfl{\"a}che bei Kontakt mit Biofl{\"u}ssigkeiten ein großes Hindernis f{\"u}r biomedizinische Anwendungen. Eine Auswahl verzweigter und linearer Molek{\"u}le mit {\"u}berlegener F{\"a}higkeit zur kolloidalen Stabilisierung von Nanopartikeln in Salz- und Zellmedienumgebung, f{\"u}r bis zu 30 Tage, wurde an die ND-Oberfl{\"a}che angebracht. Das Baukastensystem mit Azid als Außengruppen bietet eine große Vielfalt an Bindungen mit vielen Molek{\"u}len, wie z. B. Medikamenten, Farbstoffen oder Targeting-Molek{\"u}len. Das Anh{\"a}ngen von z. B. Zwitterionen an die Kette sch{\"u}tzt die ND-Oberfl{\"a}che vor der Bildung einer Proteinkorona, wenn die Partikel mit proteinhaltigen Biofl{\"u}ssigkeiten in Kontakt kommen. Die Ergebnisse der thermogravimetrischen Analyse der Beladung der ND-Oberfl{\"a}che zeigen eine signifikante Verhinderung der Proteinadsorption von bis zu 98 \% im Vergleich zu NDs ohne zwitterionische Kopfgruppen und eine lange kolloidale Stabilit{\"a}t, wenn Tetraethylenglykol (TEG) an die Oberfl{\"a}che gebunden wird. Die Vielseitigkeit des modularen Systems, um nicht nur zwitterionische Ketten, sondern auch klickbare funktionelle Molek{\"u}le an fluoreszierende Nanodiamanten (fNDs) zu binden, zeigt das Potenzial des Systems am Nanodiamanten. Unter Verwendung von Defektstrukturen, wie Stickstoff-Vakanz-Zentren (NV), k{\"o}nnen Diamantpartikel aufgrund ihres weitgehend ungiftigen Verhaltens als fluoreszierende Nanodiamanten (fNDs) f{\"u}r photostabile Markierung, Bioimaging und nanoskalige Sensorik in lebenden Zellen und Organismen verwendet werden. Um die fND-Oberfl{\"a}che zu funktionalisieren, wurde eine neuartige Mahltechnik mit Diazoniumsalzen etabliert, um ein Pfropfen auf wenig reaktive HPHT-fNDs durchzuf{\"u}hren, was zu einer hohen Oberfl{\"a}chenbeladung und einem hohen negativen Zetapotenzial f{\"u}hrt. Die Kombination der Vorteile von TEG und zwitterionhaltigen Gruppen mit der F{\"a}higkeit zum Targeting von Antik{\"o}rpern auf fND best{\"a}tigt zum ersten Mal die verbesserte kolloidale Stabilit{\"a}t in Experimenten mit lebenden Zellen. Dar{\"u}ber hinaus deuten die Ergebnisse auf eine verbesserte Corona-Abstoßung im Vergleich zu fND ohne zwitterionhaltige Kopfgruppen hin. Infolgedessen wurden die Zirkulationszeiten von 4 (fND ohne Zwitterionenkette, aber mit Antik{\"o}rper) auf 17 (mit Antik{\"o}rper und Zwitterionenketten) Stunden vergr{\"o}ßert. In nicht-biomedizinischen Anwendungen kann das modulare System als Sonde f{\"u}r Schwermetalle durch die Anbindung von Farbstoffen verwendet werden. Die Detektion von Metallen in verschiedenen Umgebungen mit hoher Selektivit{\"a}t und Spezifit{\"a}t ist eine der Voraussetzungen f{\"u}r den Kampf gegen die Umweltverschmutzung mit diesen Elementen. Pyrene sind gut geeignet und weit bekannt f{\"u}r die Fluoreszenzsensorik in verschiedenen Medien. Das angewandte Sensorprinzip beruht typischerweise auf der Bildung von intra- und intermolekularen Excimeren, was jedoch den Empfindlichkeitsbereich aufgrund der Maskierung von z.B. Quenching-Effekten durch die Excimer-Emission einschr{\"a}nkt. Diese Studie zeigt einen hochselektiven, strukturstabilen chemischen Sensor, der auf der monomeren Fluoreszenz von Pyrenanteilen mit Triazolgruppen basiert. Dieser Sensor kann Cu2+, Pb2+ und Hg2+ in organischen L{\"o}sungsmitteln {\"u}ber einen weiten Konzentrationsbereich quantitativ nachweisen, auch in Gegenwart von ubiquit{\"a}ren Ionen wie Na+, K+, Ca2+ und Mg2+. Die stark emittierende Fluoreszenz des Sensors mit einer langen Lebensdauer von 165 ns wird durch eine 1:1-Komplexbildung bei Zugabe von Metallionen in Acetonitril gel{\"o}scht. Bei Zugabe eines zehnfachen {\"U}berschusses des Metallions zum Sensor bilden sich Agglomerate mit einem Durchmesser von etwa 3 nm. Aufgrund der komplexen Wechselwirkungen im System werden konventionelle lineare Korrelationen nicht f{\"u}r alle Konzentrationen beobachtet. Daher wird ein kritischer Vergleich zwischen der konventionellen Job-Plot-Interpretation, der Methode von Benesi-Hildebrand und einem nicht-linearen Fit vorgestellt. Das vorgestellte System erm{\"o}glicht die spezifische und robuste Erfassung von medizinisch und {\"o}kologisch relevanten Ionen im gesundheitsrelevanten nM-Bereich und k{\"o}nnte z. B. zur {\"U}berwachung der entsprechenden Ionen in Abfallstr{\"o}men eingesetzt werden. Doch h{\"a}ufig landen diese Abfallstr{\"o}me in empfindlichen Aquakulturen, wo eine solche Sensortechnik nur funktioniert, wenn die Sonde wasserl{\"o}slich ist, um die Ausbreitung und Bildung von Umweltsch{\"a}den durch Schwermetalle zu {\"u}berwachen. Viele Chemosensoren arbeiten nur in bestimmten L{\"o}sungsmitteln und unter hochreinen Bedingungen quantitativ. In dieser Arbeit wird eine Methode zur Stabilisierung von wasserunl{\"o}slichen Chemosensoren auf Nanodiamanten in salzhaltigem Wasser unter Beibehaltung der Sensoreffektivit{\"a}t und -spezifit{\"a}t sowie der kolloidalen Stabilit{\"a}t vorgestellt. Zus{\"a}tzlich wird die Sensorf{\"a}higkeit in organischen L{\"o}sungsmitteln beibehalten. Diese Studie gibt Einblick in die Absorptionsf{\"a}higkeit von Pyren-Derivaten an der Nanodiamant-Oberfl{\"a}che und einen Weg, diese reversibel zu desorbieren. Außerdem beweist das System, dass in Anwesenheit von 95 \% Sauerstoffatmosph{\"a}re bei der Fluoreszenzmessung die Ergebnisse nicht von denen in Argonatmosph{\"a}re abweichen. Dar{\"u}ber hinaus st{\"o}rt das Vorhandensein g{\"a}ngiger Ionen im Wasser die kolloidale Stabilit{\"a}t der NDs nicht und hat auch keinen Einfluss auf die Sensorfunktionalit{\"a}t und ist somit ein vielversprechender Kandidat f{\"u}r Messungen ohne aufw{\"a}ndige Pr{\"a}parationsschritte.}, language = {en} } @article{KarakStepanenkoAddicoatetal.2022, author = {Karak, Suvendu and Stepanenko, Vladimir and Addicoat, Matthew A. and Keßler, Philipp and Moser, Simon and Beuerle, Florian and W{\"u}rthner, Frank}, title = {A Covalent Organic Framework for Cooperative Water Oxidation}, series = {Journal of the American Chemical Society}, volume = {144}, journal = {Journal of the American Chemical Society}, number = {38}, issn = {0002-7863}, doi = {10.1021/jacs.2c07282}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287591}, pages = {17661-17670}, year = {2022}, abstract = {The future of water-derived hydrogen as the "sustainable energy source" straightaway bets on the success of the sluggish oxygen-generating half-reaction. The endeavor to emulate the natural photosystem II for efficient water oxidation has been extended across the spectrum of organic and inorganic combinations. However, the achievement has so far been restricted to homogeneous catalysts rather than their pristine heterogeneous forms. The poor structural understanding and control over the mechanistic pathway often impede the overall development. Herein, we have synthesized a highly crystalline covalent organic framework (COF) for chemical and photochemical water oxidation. The interpenetrated structure assures the catalyst stability, as the catalyst's performance remains unaltered after several cycles. This COF exhibits the highest ever accomplished catalytic activity for such an organometallic crystalline solid-state material where the rate of oxygen evolution is as high as ∼26,000 μmol L\(^{-1}\) s\(^{-1}\) (second-order rate constant k ≈ 1650 μmol L s\(^{-1}\) g\(^{-2}\)). The catalyst also proves its exceptional activity (k ≈ 1600 μmol L s\(^{-1}\) g\(^{-2}\)) during light-driven water oxidation under very dilute conditions. The cooperative interaction between metal centers in the crystalline network offers 20-30-fold superior activity during chemical as well as photocatalytic water oxidation as compared to its amorphous polymeric counterpart.}, 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} } @article{MetznerHerzogHeckeletal.2022, author = {Metzner, Valentin and Herzog, Gloria and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and Otto, Christoph and Fassnacht, Martin and Geier, Andreas and Seyfried, Florian and Dischinger, Ulrich}, title = {Liraglutide + PYY\(_{3-36}\) combination therapy mimics effects of Roux-en-Y bypass on early NAFLD whilst lacking-behind in metabolic improvements}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {3}, issn = {2077-0383}, doi = {10.3390/jcm11030753}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255244}, year = {2022}, abstract = {Background: Treatment options for NAFLD are still limited. Bariatric surgery, such as Roux-en-Y gastric bypass (RYGB), has been shown to improve metabolic and histologic markers of NAFLD. Glucagon-like-peptide-1 (GLP-1) analogues lead to improvements in phase 2 clinical trials. We directly compared the effects of RYGB with a treatment using liraglutide and/or peptide tyrosine tyrosine 3-36 (PYY\(_{3-36}\)) in a rat model for early NAFLD. Methods: Obese male Wistar rats (high-fat diet (HFD)-induced) were randomized into the following treatment groups: RYGB, sham-operation (sham), liraglutide (0.4 mg/kg/day), PYY\(_{3-36}\) (0.1 mg/kg/day), liraglutide+PYY\(_{3-36}\), and saline. After an observation period of 4 weeks, liver samples were histologically evaluated, ELISAs and RNA sequencing + RT-qPCRs were performed. Results: RYGB and liraglutide+PYY\(_{3-36}\) induced a similar body weight loss and, compared to sham/saline, marked histological improvements with significantly less steatosis. However, only RYGB induced significant metabolic improvements (e.g., adiponectin/leptin ratio 18.8 ± 11.8 vs. 2.4 ± 1.2 in liraglutide+PYY\(_{3-36}\)- or 1.4 ± 0.9 in sham-treated rats). Furthermore, RNA sequencing revealed a high number of differentially regulated genes in RYGB treated animals only. Conclusions: The combination therapy of liraglutide+PYY\(_{3-36}\) partly mimics the positive effects of RYGB on weight reduction and on hepatic steatosis, while its effects on metabolic function lack behind RYGB.}, language = {en} }