Welcome to JLUpub

Communities in JLUpub

Select a community to browse its collections.

Now showing 1 - 2 of 2

JLUdata
Forschungsdatenrepositorium
JLUdocs
Schriftenrepositorium

Recent Submissions

Analyse der Bedeutung von onkogenem K-RasG12C und TGF-β1 in der epithelialen-mesenchymalen Transition nicht-kleinzelliger Lungenkarzinomzellen
(2026) Nagel, Liz Victoria
Die epitheliale-mesenchymale Transition (EMT) kann ein zentraler Vorgang in der Metastasierung von Karzinomen sein, bei dem epitheliale Karzinomzellen ganz oder teilweise mesenchymale Charakteristika annehmen. Dieser Prozess geht einher mit einem Wechsel der Proteinausstattung: Epitheliale Proteine wie E-Cadherin und Zytokeratin werden herab- und mesenchymale Proteine wie N-Cadherin und Vimentin heraufreguliert. Dadurch kommt es zum Abbau der Zell-Zell-Kontakte und Veränderungen des Zytoskeletts. Einer der zentralen Modulatoren der EMT ist der Transforming-Growth-Factor β1 (TGF-β1). Dieser induziert die Expression einer Reihe von Transkriptionsfaktoren, wie Slug, Snail, Twist, ZEB 1 oder ZEB 2, welche die EMT vorantreiben. Die EMT ist auch ein wichtiger Vorgang in der Metastasierung des nicht- kleinzelligen Bronchialkarzinoms (NSCLC), einer Entität, die oftmals Treibermutationen im KRAS Gen aufweist. Am häufigsten findet sich die spezifische Mutation K-RasG12C. Diese führt zu einem konstitutiv aktiven Ras Signalweg und damit zur Karzinogenese. Das Ziel dieser Arbeit war es, zu untersuchen, ob der Ras und TGF-β1 Signalweg in der EMT des NSCLCs synergieren. Hierzu wurden die NSCLC Zellen sowohl mit spezifischen K-RasG12C Inhibitoren (AMG 510 oder MRTX 849) als auch mit TGF-β1 behandelt. Die Proteinmenge und -lokalisation verschiedener EMT-Markerproteine, Transkriptionsfaktoren und -regulatoren sowie Zelladhäsionsproteine, die eine mögliche Rolle im EMT Prozess spielen, wurden mittels Western Blot und Immunzytochemie analysiert. Die Ergebnisse dieser Arbeiten zeigen, dass die Proteinmenge der EMT- Transkriptionsfaktoren Slug und ZEB 1 durch die K-RasG12C Inhibition verringert und durch die TGF-β1 Stimulation gesteigert wird. In der Literatur gibt es für diese Transkriptionsfaktoren Hinweise auf eine gemeinsame Regulation durch den Ras und TGF-β Signalweg. Die Ergebnisse der vorliegenden Arbeit unterstützen diese Interpretation. Diese Beobachtungen konnten vor allem in den H358 Zellen gemacht werden. Die H23 und HCC44 Zellen hingegen, zeigten kaum Veränderungen durch die K-RasG12C Inhibition und / oder die TGF-β1 Stimulation. Auch für die RNA Splicing Proteine ERSP 1 und ESRP 2 ergaben sich Hinweise auf eine gemeinsame Regulation. Die anderen in dieser Arbeit untersuchten Zelllinien und Proteine zeigten einen weitgehend parallelen Verlauf der beiden Signalwege ohne Hinweise auf Interaktionen. Der genaue molekulare Mechanismus der Synergie des Ras und TGF-β Signalwegs kann anhand dieser Untersuchungen jedoch nicht bestimmt werden. Dieses Verständnis wäre für die Entwicklung zielgerichteter Therapien von entscheidendem Vorteil.
References to unbiased sources increase the helpfulness of community fact-checks
(2025) Solovev, Kirill; Pröllochs, Nicolas
Community-based fact-checking is a promising approach to address misinformation on social media at scale. However, an understanding of what makes community-created fact-checks helpful to users is still in its infancy. In this paper, we analyze the determinants of the helpfulness of community-created fact-checks. For this purpose, we draw upon a unique dataset of real-world community-created fact-checks and helpfulness ratings from X’s (formerly Twitter) Community Notes platform. Our empirical analysis implies that the key determinant of helpfulness in community-based fact-checking is whether users provide links to external sources to underpin their assertions. On average, the odds for community-created fact-checks to be perceived as helpful are 2.33 times higher if they provide links to external sources. Furthermore, we demonstrate that the helpfulness of community-created fact-checks varies depending on their level of political bias. Here, we find that community-created fact-checks linking to high-bias sources (of either political side) are perceived as significantly less helpful. This suggests that the rating mechanism on the Community Notes platform successfully penalizes one-sidedness and politically motivated reasoning. These findings have important implications for social media platforms, which can utilize our results to optimize their community-based fact-checking systems.
The paradox of endometriosis in Mayer-Rokitansky-Kuster-Hauser syndrome : applying three criteria to discriminate between retrograde menstruation/implantation and coelomic metaplasia/embryonic cell rests theories
(2026) Konrad, Lutz; Riaz, Muhammad Assad; Zeppernick, Felix; Zeppernick, Magdalena; Meinhold-Heerlein, Ivo; Salmeri, Noemi; Viganò, Paola; Somigliana, Edgardo; Vercellini, Paolo
Background/Objectives: The scientific community is still divided between supporters of the implantation theory and researchers who advocate the theory of coelomic metaplasia/embryonic cell remnants to explain the initiation of endometriosis. A frequently cited argument in favor of the coelomic metaplasia/embryonic cell remnants theory is the occurrence of endometriosis in the Mayer-Rokitansky-Kuster-Hauser syndrome, since retrograde menstruation is not possible without endometrium. However, nearly all women with uterovaginal agenesis have uterine remnants that harbour islets of endometrium. Methods: To verify the validity of the coelomic metaplasia/embryonic cell rests theory, we analysed all reports of endometriosis in patients with Mayer-Rokitansky-Kuster-Hauser syndrome without endometrium, published between 1980 and 2025. Three criteria had to be met in order to clearly demonstrate the absence of endometrium and the presence of endometriosis: (i) preoperative imaging, (ii) surgical visualization, and (iii) histological examination. Results: None of the nine reports fully met all three criteria, and the presence of endometrium could never be ruled out. In addition, we used ten characteristics to assess the ‘goodness’ of a theory: testability, logical coherence, conceptual clarity and comprehensibility, external consistency, empirical validity, predictive power, parsimony, broad applicability, practical utility, and heuristic value. Conclusions: Overall, the implantation theory appears to fully satisfy all criteria to explain the onset of endometriosis in Mayer-Rokitansky-Kuster-Hauser syndrome. In contrast, the coelomic metaplasia/embryonic cell rests theory satisfies eight criteria only partly and does not satisfy two of them. Therefore, the null hypothesis that endometriosis can be present in the absence of endometrium in patients with utero-vaginal agenesis can be reasonably rejected.
Engagement with political videos on TikTok during the 2025 German federal election
(2026) Solovev, Kirill; Drolsbach, Chiara; Demirel, Emma; Pröllochs, Nicolas
Short-form video platforms like TikTok reshape how politicians communicate and have become important tools for electoral campaigning. Yet it remains unclear what kinds of political messages gain traction in these fast-paced, algorithmically curated environments, which are particularly popular among younger audiences. In this study, we use computational content analysis to analyze a comprehensive dataset of N= 25,292 TikTok videos posted by German politicians in the run-up to the 2025 German federal election. Our empirical analysis shows that videos expressing negative emotions (e.g., anger, disgust) and outgroup animosity were significantly more likely to generate engagement than those emphasizing positive emotion, relatability, or identity. Furthermore, ideologically extreme parties (on both sides of the political spectrum) were both more likely to post this type of content and more successful in generating engagement than centrist parties. Taken together, these findings suggest that divisive political communication tends to receive higher engagement than unifying messages on TikTok, thereby potentially benefiting extreme actors who are more inclined to capitalize on this logic.
NORG - Nitrogen ORGanizer : a novel web-based system for cryopreservation and freezer management
(2026) Keller, Marvin; Przybilla, Maximilian; Sehring, Jannik; Schmid, Kai; Kauer, Thomas; Dörmer, Felix; Ritschel, Nadja; May, Annika; Schlierbach, Hannah; Schmidt, Gudrun; Leib, Kerstin; Stephan, Chiana; Jenike, Elena; Selignow, Carmen; Frank, Angelina; Umathum, Vincent; Schänzer, Anne; Németh, Attila; Sohrabi, Keywan; Acker, Till; Heller, Nick; Dohmen, Hildegard; Amsel, Daniel
The preservation of samples, whether they are from humans, cell lines, animals, plants, or other resources, usually follows a similar process. They are packaged in appropriate containers, whether tubes for cryogenic containers or boxes in freezers or other systems. For this biological sample database to be and remain useful, the samples must be appropriately cataloged and consecutively maintained in a document. After all, only when it is clear where which sample is located, the biological database has a value. In many cases this documentation is done in local spreadsheets and saved in e.g. CSV or XLSX format. In some cases, there are even handwritten records to comprehend where which sample is located. The intention behind a biological database is mainly the collection of rare material, but also the withdrawal of this material from the storage for further analysis, partly in-house but presumably also with external cooperation partners. If a sample is now taken from a container that has already been completely filled and stored, this empty space can only be re-allocated with a sample with great administrative effort, since new samples would otherwise be stored in the container that is currently active. With NORG we address this problem. NORG offers a stand-alone software solution via webservices to catalog e.g. nitrogen tanks and store the contents digitally with a color-coding for the filling level of the storages. In addition, NORG can trace who sent which sample to whom and when, for example to have it analyzed by a cooperation partner.