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Neue Versuche über Ausscheidung einiger Aminosäuren durch den Harn
Get PDFDigitalisat der Ausgabe von 1918, erschienen 202
A Radical-Cationic Covalent Organic Framework to Accelerate Polysulfide Conversion for Long-Durable Lithium–Sulfur Batteries
Get PDFCovalent organic frameworks (COFs) have emerged as promising metal-free sulfur hosts to facilitate the conversion kinetics and suppress the shuttling effect of lithium polysulfides (LiPSs) in lithium–sulfur (Li–S) batteries. However, constructing COFs with stable and high electrocatalytic functionality for LiPS conversion remains unexplored. Herein, we develop a radical-cationic COF (R-TTF•+-COF) with superior electrical conductivity of 3.9 S m–1 at room temperature, which features both nucleophilic and electrophilic sites for effective LiPS chemisorption and conversion. With this novel radical-based catalyst, the Li–S battery achieves superior longevity of 1500 cycles with a capacity fading of 0.027% per cycle at a current density of 0.5 C. The capacity retention of the Li–S battery based on R-TTF•+-COF at the current density of 2.0 C is nearly twice as high compared to a COF without radicals. The crucial role of radical cations in catalyzing LiPS conversion has been systematically elucidated through solid-state nuclear magnetic resonance spectroscopy, electron paramagnetic resonance spectroscopy, and theoretical simulations, which verify the reversible interactions between LiPSs and [TTF]2•+ moieties. This intriguing radical-assisted mechanism opens a new avenue for designing efficient catalytic sulfur hosts using organic molecules, offering a significant step toward the practical application of Li–S batteries
Supershear Rupture Along the Sagaing Fault Seismic Gap: The 2025 Myanmar Earthquake
No full textThe 28 March 2025 Mw 7.7 Myanmar earthquake on the Sagaing fault caused widespread building collapses and over 3800 fatalities, as well as strong shaking in Bangkok. Highfrequency backprojection very early on revealed an 500 km rupture. Following a bilateral subshear propagation, the rupture accelerated southward to at least 5.3 km/s, reaching the stable supershear regime, as also confirmed by Mach-cone analysis with Love waves. Pixel tracking analysis from optical and radar imagery confirms the rupture length and indicates a peak surface offset of 5 m and average offsets of 3-4 m along the rupture zone. Pseudodynamic rupture inversion constrained by seismic waveforms and the radarinterferometric deformation field indicates 4 m slip over 15 km depth range. The earthquake yielded unusually few aftershocks; its supershear rupture likely released most of the accumulated stress. It appears that the rupture almost certainly broke the Sagaing gap and very likely overlapped completely with the 1956 M 7.0 event. It may also have partially overlapped with the 1946 M 7.8 rupture zone in the north and the 1930 M 7.5 event in the south. Acceleration to supershear only started in the gap area, and the rupture decelerated and arrested after moving into the previously broken segment
Between Degania and Tel Aviv: The urban-rural binary in Zionist intellectual history, pre-state settlement design, and nation(-state) building
No full textThe general historiography of Israel is still shaped by the assumption that Zionism was “anti-urban,” despite the country’s early de facto urbanization and comprehensive scholarship contradicting this claim. Addressing these tensions, this article revisits the Zionist intellectual and settlement history in the pre-state period. To many Zionists, I argue, the city symbolized Western-style modernization and development. Their attitudes toward it were, therefore, more ambivalent and indeed synthetic: “Rurban” settlement designs provided a compromise between Euro-modernity and a “return to the East.” In this light, the Yishuv/Israel’s eventual “turn to the city” must also be understood in the context of a growing commitment to European civilization
Discrete component model to explain the photophysics of bay-functionalized perylene bisimide derivatives
No full textBay functionalization of perylene bisimides (PBIs) is a widely used strategy to tailor their electronic structure. However, most bay-functionalized PBIs are symmetric, bearing identical substituents. Here, we present an asymmetrically functionalized PBI with distinct groups at the bay positions. The introduction of an aldehyde intermediate at the bay positions enables stepwise formation of benzimidazole (Imi) and dicyanoethylene (DCE) moieties. In the resulting asymmetric mono-Imi-mono-DCE-PBI, Imi and DCE act as electron-donating and electron-withdrawing groups, respectively. Comparing its spectral features with symmetric di-Imi-PBI and di-DCE-PBI reveals that its absorption spectrum is dominated by the DCE group, while emission is governed by the Imi group. The photoluminescence quantum yield (PLQY) of this asymmetric PBI lies between di-Imi-PBI and di-DCE-PBI. Furthermore, acid titration of di-Imi-PBI yielded another asymmetric PBI through one-sided protonation. Unlike mono-Imi-mono-DCE-PBI, this partially protonated derivative shows the lowest PLQY value compared with its symmetric counterparts. Theoretical calculations provided molecular orbital energy levels of the PBI core and bay substituents. Applying a discrete component model, we rationalized the photo-induced charge transfer (PICT) behavior. This analysis shows that additional electron transfer from the PBI core to the benzimidazolium (Imi + ) moiety in the protonated derivative accounts for the pronounced fluorescence quenching observed
Aetokthonotoxin, the Causative Agent of Vacuolar Myelinopathy, Uncouples Oxidative Phosphorylation due to Protonophore Activity
No full textAetokthonotoxin (AETX) is an emerging environmental toxin produced by the freshwater cyanobacterium Aetokthonos hydrillicola. Accumulating in the food chain, it causes vacuolar myelinopathy, a neurological disease affecting a wide range of wildlife characterized by the development of large intramyelinic vacuoles in the white matter of the brain. So far, the mode of action of AETX is unknown. After discovering that AETX is cytostatic and arrests cancer cell lines in the G1 phase, metabolomic profiling of AETX-treated cells as well as an assessment of the physicochemical properties of the compound suggested that AETX is a weakly acidic uncoupler of mitochondrial respiration. We confirmed this hypothesis by in vitro assays on mammalian cells, finding that AETX has the expected effects on mitochondrial network morphology, mitochondrial membrane potential, and oxygen consumption rate, resulting in affected ATP generation. We confirmed that AETX is capable of transporting protons across lipid bilayers. In summary, we demonstrate that AETX is a protonophore that uncouples oxidative phosphorylation in mitochondria, which is the primary event of AETX intoxication
Time-dependent trajectory of a one-dimensional Gaussian non-Markovian observable does not reveal its nonequilibrium character
No full textWhen analyzing experimental or simulation time-series data, the question arises whether it is possible to tell from the mere observation of the time-dependent trajectory of a one-dimensional observable whether the system is in equilibrium or not. We here consider the nonequilibrium version of the generalized Langevin equation for a Gaussian non-Markovian observable and show that (i) the multipoint joint distribution solely depends on the two-point correlation function and that (ii) for any nonequilibrium process an equilibrium process with uniquely determined parameters can be found that produces the same two-point correlation function. Since the multipoint joint distribution completely characterizes the dynamics of an observable, we conclude that the nonequilibrium character of a system, in contrast to its non-Markovianity, cannot be read off from the one-dimensional trajectory of a Gaussian observable. These findings are relevant for human cancer and algae cells, whose single-cell velocity distributions have been found to be Gaussian within the data accuracy
Bacterial contamination of irrigation fluid and suture material during arthroscopic ACL reconstruction and meniscus surgery
No full textEinleitung: Arthroskopische Eingriffe sind eine effiziente minimal-invasive Behandlungsoption, um Kniegelenksbeschwerden zu therapieren und zu lindern, dennoch können in seltenen Fällen auch schwerwiegende Komplikationen wie Gelenksinfektionen postinterventionell auftreten. Postarthroskopische Gelenksinfektionen können für Patient*innen folgenschwer sowie für behandelnde Ärzt*innen herausfordernd sein. Bei arthroskopischen Eingriffen werden Gelenke kontinuierlich mit Spüllösungen gespült und die Flüssigkeit dabei in einem Reservoir aufgefangen. Ziel dieser Studie war es die bakterielle Kontamination der Spülflüssigkeit im zeitlichen Verlauf zu untersuchen und ebenso mögliche bakterielle Kontamination auf den Nahtmaterialien zu identifizieren, um so Aussagen treffen zu können, welchen Einfluss die Operations-Zeit und weitere Faktoren (Eingriffsart, Alter, Geschlecht) auf die Kontaminationsrate sowie das Erregerspektrum haben.
Methodik: In dieser Studie wurden 155 Patient*innen eingeschlossen. 58 erhielten eine arthroskopische Rekonstruktion des vorderen Kreuzbandes (VKB), 63 einen arthroskopischen meniskus-chirurgischen Eingriff (Meniskusnaht oder -teilresektion) und 34 eine aus beidem vorher genannten Eingriffen kombinierte Operation (OP). Alle 15 Minuten wurden Proben der arthroskopischen Spülflüssigkeit aus dem Reservoir entnommen und mikrobiologisch hinsichtlich bakterieller Kontamination durch 14-tägige kulturelle Anzucht untersucht. Bei Kontaminationsnachweis erfolgte die Identifikation des Erregers. Darüber hinaus wurde bei VKB-Rekonstruktion und Meniskusnaht überschüssiges Nahtmaterial als Probe gewonnen und analog zu den Spülflüssigkeitsproben mikrobiologisch untersucht. Alle Patient*innen wurden 6 und 12 Wochen sowie 1 Jahr postoperativ nachuntersucht, um mögliche Kniegelenksinfektionen zu identifizieren.
Ergebnisse: Es wurde eine starke Korrelation zwischen fortschreitender OP-Dauer und Anteil der bakteriell kontaminierten Spülflüssigkeitsproben festgestellt (ρ = 0,886; p = 0,019). Nahtmaterialproben zeigten in 28,43% (n=29/102) der Fälle bakterielle Kontamination, Spülflüssigkeitsproben in 18,71% (n=29/155). Trotz hoher Kontaminationsraten wurde lediglich eine postarthroskopische Kniegelenksinfektion festgestellt, die durch S. lugdunensis hervorgerufen wurde.
Schlussfolgerung: Da die bakterielle Kontamination von Spülflüssigkeit zeitabhängig mit der OP-Dauer steigt und auch Nahtmaterial hohe Kontaminationsraten aufweist, sollte jeglicher Kontakt des Instrumentariums sowie der Hände des operierenden Personals mit dem Spülflüssigkeitsreservoir und diesen potenziell kontaminierten Materialien vermieden werden. Die OP-Dauer sollte so kurz wie möglich gehalten werden.Introduction: Arthroscopic procedures are an efficient minimally-invasive option to treat pathologies of the knee joint and relieve patient discomfort. Nevertheless, one must always be aware of risks and complications, as post-arthroscopic joint infections can be severe and challenging for the treatment team, greatly impacting patient’s wellbeing. During the procedure the joint is continuedly irrigated with a sterile solution, which accumulates in a reservoir. The aim of this study was to identify the rate of bacterial contamination of the irrigation fluid over time and of suture and fixation material, in order to find and potentially eliminate risk factors for post-arthroscopic infection of the knee joint.
Materials and methods: Of the 155 patients included, 58 underwent reconstruction of the anterior cruciate ligament (ACL), 63 received meniscal repair and 34 patients underwent combined ACL reconstruction and meniscal repair. Samples of irrigation fluid were collected from the reservoir every 15 minutes during surgery and sent for microbiological analysis with a 14-day incubation period. In the case of positive microbiological findings, specific pathogens were identified. In addition, samples of the suture and fixation material during ACL reconstruction and meniscus repair were collected and likewise examined. All patients were seen 6 and 12 weeks as well as 1 year after surgery in our outpatient department and examined for clinical signs of infection.
Results: A very strong correlation between advanced time of surgery and rate of bacterial contamination of the irrigation fluid was found (ρ = 0.886; p = 0.019). Suture and fixation material was contaminated in 28.43% (n=29/102) of cases, irrigation fluid in 18.71% (n=29/155). Despite the high contamination rate only one post-arthroscopic infection of the knee joint was found, caused by S. lugdunensis.
Conclusion: As the rate of bacterial contamination of irrigation fluid increased over time and suture and fixation material showed a high contamination rate as well, contact of instruments or the surgeons’ hands with the fluid reservoirs and potentially contaminated material should be avoided. In addition, the duration of the surgery should be as short as possible
Fallzahlplanung für multiple Vergleiche
No full textDetermining the appropriate sample size of (pre-)clinical studies is critical for ethical and scientific reasons. The sample size must be large enough to detect meaningful effects with sufficient statistical power, yet small enough to minimize the number of animals or participants exposed to potential study-related risks. In many (pre-)clinical studies, multiple groups are compared, e.g., when different dose levels of a compound are examined. For the comparison of multiple groups, multiple contrast tests have been shown to be superior to, e.g., analysis of variance methods, since they provide a high power while ensuring a coherent global and individual test decision. However, existing sample size calculation methods for these tests have limitations, often relying on unrealistic assumptions like variance homogeneity, which are particularly unsuitable for rather small animal trials.
In Thesis Article 1, my supervisor and I developed a novel sample size planning approach for parametric multiple comparison procedures that account for variance heterogeneity among groups. In addition, we introduced planning strategies for nonparametric multiple contrast tests using pairwise ranking procedures that do not rely on any distributional assumption. In Thesis Article 2, my coauthors and I expanded these methods, proposing sample size planning techniques for nonparametric multiple comparisons based on global ranks. All of these methods have been integrated into new software. In Thesis Article 3, we applied a nonparametric multiple contrast test. In this dissertation, the data from that study is used to plan a follow-up trial for illustration purposes.
This work introduces new methods tailored but not limited to the specific conditions of animal testing and makes sample size planning more accurate and studies more efficient. The approach avoids unrealistic assumptions, accommodates small sample sizes, and ultimately reduces the number of participants needed to achieve a predefined statistical power. In addition, the methodologies are made accessible through user-friendly software.
This work addresses key methodological limitations in sample size calculations for (pre-) clinical trials by offering solutions in several areas: 1) sample size calculation for parametric multiple contrast procedures for heteroscedastic normal data, 2) sample size calculation for nonparametric multiple contrast procedures based on pairwise-defined ranks, 3) sample size calculation for nonparametric multiple contrast procedures based on global ranks, and 4) the development of accessible software. These improvements in sample size planning approaches enhance study efficiency and ethical standards.Die Bestimmung einer geeigneten Fallzahl (prä-)klinischer Studien ist aus ethischen und wissenschaftlichen Gründen unabdingbar. Die Fallzahl muss groß genug sein, um Effekte mit ausreichender statistischer Power nachzuweisen, und zugleich klein genug, um die Zahl der Tiere oder Teilnehmenden, die potenziell studienbedingten Risiken ausgesetzt sind, zu minimieren. In vielen (prä-)klinischen Studien werden mehrere Gruppen verglichen, z.B. bei der Untersuchung verschiedener Dosisstufen eines Wirkstoffs. Für den Vergleich mehrerer Gruppen sind multiple Kontrasttests besser geeignet als z.B. Varianzanalyseverfahren, da sie eine hohe Power und eine konsistente globale und individuelle Testentscheidung gewährleisten. Bisherige Methoden zur Berechnung der Fallzahl für diese Tests weisen erhebliche Limitierungen auf, da sie häufig auf unrealistischen Annahmen wie Homoskedastizität beruhen, was vor allem bei Tierversuchen mit eher kleinen Fallzahlen unangemessen ist.
In Promotionsartikel 1 haben mein Betreuer und ich eine neue Methode zur Fallzahlplanung für parametrische multiple Kontrasttests entwickelt, die Varianzheterogenität zwischen den Gruppen zulässt. Darüber hinaus haben wir Methoden zur Planung nichtparametrischer multipler Kontrasttests mittlels paarweiser Rangvergaben entwickelt, die keine Verteilungsannahme treffen. In Promotionsartikel 2 haben meine Koautoren und ich diese Methoden erweitert und Methoden zur Fallzahlplanung für nichtparametrische multiple Kontrasttests basierend auf globalen Rängen vorgeschlagen. Alle Methoden wurden in eine neue Software integriert. In Promotionsartikel 3 haben wir einen nichtparametrischen multiplen Kontrasttest angewendet. In dieser Dissertation werden die Daten aus dieser Studie zur Planung einer Folgestudie zu Illustrationszwecken verwendet.
In dieser Arbeit werden neue Methoden vorgestellt, die besser auf die Anforderungen präklinischer Studien zugeschnitten sind, da sie auf realistischen Annahmen basieren, auch bei kleinen Stichproben funktionieren und letztlich weniger Tiere benötigen, um die gewünschte statistische Power zu erreichen. Außerdem sind alle Methoden mithilfe einer benutzerfreundlichen Software leicht anzuwenden.
Diese Arbeit leistet einen wesentlichen Beitrag zur Reduzierung methodischer Schwächen bei der Fallzahlberechnung in (prä-)klinischen Studien und bietet Lösungen in mehreren Bereichen: 1) Berechnung der Fallzahl parametrischer multipler Kontrasttests bei heteroskedastischen normalverteilten Daten, 2) Berechnung der Fallzahl nichtparametrischer multipler Kontrasttests basierend auf paarweise definierten Rängen, 3) Berechnung der Fallzahl nichtparametrischer multipler Kontrasttests basierend auf globalen Rängen und 4) die Entwicklung einer Software. Diese Verbesserungen in den Methoden zur Fallzahlberechnung erhöhen letztlich die Studieneffizienz und tragen zu hohen ethischen Standards bei
A database of words and pictures for investigating phonological-semantic processing and interaction in language processing: Validation and application
No full textAn increasing number of studies aim to directly compare aspects of linguistic processing in word production and comprehension using controlled experiments with shared stimuli across modalities. However, the available resources allowing for such investigations are scarce, particularly for languages other than English. To address this gap, we present an open-source database of 151 German words and related picture stimuli. The items are drawn from two well-investigated semantic categories – animals and tools – and differ phonologically by either starting with a labial or a coronal speech sound. The database includes human ratings for depictive accuracy, familiarity, action relatedness, valence, arousal of the pictures, and familiarity, action relatedness, valence, arousal, and imageability of the words. In a set of analyses, we show that the ratings we collected have good reliability and external validity, and align well with previously obtained data from lexical and pictorial databases. The database is complemented with comprehensive information about phonetic/phonological, lexical, morphological, and semantic properties of the words, as well as about luminosity and visual complexity of the corresponding pictures. We finally present a matched stimulus set obtained from the database, as a ready-to-use resource for psycho- and neurolinguistic studies examining semantic and phonological processing along with their interaction in language production and comprehension. The word-picture database, together with the matched stimulus set, are freely available at https://osf.io/k64nh/