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Abstract Epithelia are polarized layers of cells that line the outer and inner surfaces of organs. At the basal side, the epithelial cell layer is supported by a basement membrane, which is a thin polymeric layer of self‐assembled extracellular matrix (ECM) that tightly adheres to the basal cell surface. Proper shaping of epithelial layers is an important prerequisite for the development of healthy organs during the morphogenesis of an organism. Experimental evidence suggests that local degradation of the basement membrane is one of the mechanisms that can drive epithelial folding. However, how folding emerges in the absence of tissue growth remains elusive. Here, we present a coarse‐grained plate theory model of the basement membrane that assumes force balance between i) cell‐transduced active forces and ii) deformation‐induced elastic forces. We verify key assumptions of this model through experiments in the Drosophila wing disc epithelium and demonstrate that the model can explain the emergence of outward epithelial folds upon local plate degradation. The model accounts for local degradation of the basement membrane as a mechanism for the generation of epithelial folds in the absence of epithelial growth.

Abstract The actin cortex is an active polymer network underneath the plasma membrane at the periphery of mammalian cells. It is a major regulator of cell shape through the generation of active cortical tension. In addition, the cortex constitutes a mechanical shield that protects the cell during mechanical agitation. Cortical mechanics is tightly controlled by the presence of actin cross‐linking proteins that dynamically bind and unbind actin filaments. Cross‐linker actin bonds are weak non‐covalent bonds whose bond lifetime is likely affected by mechanical tension in the actin cortex making cortical composition inherently mechanosensitive. Here, a quantitative study of changes in cortex composition and turnover dynamics upon short‐lived peaks in active and passive mechanical tension in mitotic HeLa cells is presented. These findings dsclose a twofold mechanical reinforcement strategy of the cortex upon tension peaks entailing i) a direct catch‐bond mechanosensitivity of cross‐linkers filamin and α‐actinin and ii) an indirect cortical mechanosensitivity that triggers actin cortex reinforcement via enhanced polymerization of actin. Thereby a “molecular safety belt” mechanism that protects the cortex from injury upon mechanical challenges is disclosed.

Abstract Background Bedside teaching is essential to foster core clinical competences in medical education, especially in Neurology. However, bedside skills are declining and new concepts to enhance the effectiveness of bedside teaching are needed, also in view of limited in-person teaching possibilities in the ongoing pandemic situation. If theoretical knowledge is taught prior to in-person sessions this might allow to better focus on practical application aspects during bedside teaching. We thus aimed to answer the question to what extent such an approach can enhance the effectiveness of neurological bedside teaching. Methods In this prospective controlled study, neurological bedside courses following a traditional and a flipped classroom (FC) approach were compared with regards to their effects on theoretical knowledge and practical skills of medical students. Evaluations were obtained from 161 students and their lecturers participating in a neurological bedside teaching course at a German university hospital between October 2020 and July 2021. Students were randomly assigned to course dates. However, the 74 students assigned to course dates from May to July 2021 completed a mandatory online preparation course prior to the bedside teaching. These students served as the interventional group (IG) and the remaining 87 students formed the control group (CG). Ratings of knowledge and skills provided by the students and their lecturers on numerical rating scales served as primary outcome measures. Moreover, the time needed to recapitulate theoretical contents during the in-person teaching session was assessed as a secondary outcome measure. Group comparisons were performed using t-statistics. Results Theoretical knowledge upon entering the course was rated significantly higher in the IG by the students (p

Abstract Background The COVID-19 pandemic poses a huge challenge for clinical teaching due to contact restrictions and social distancing. Medical teachers have to balance potential risks and benefits of bedside teaching, especially in course formats intended to foster practical clinical skills. In this context, we aimed to address the question, whether presence-based teaching formats without patient involvement are suitable to teach practical skills. Methods In this quasi-experimental study, presence-based teaching formats with and without patient contact were retrospectively compared regarding their effects on medical students’ theoretical knowledge and practical skills, i.e. the performance and clinical interpretation of the neurological exam. To this end, evaluations from 102 students and their lecturers participating in a neurological bedside teaching course at a German university hospital between October 2020 and April 2021 were obtained. Students were initially randomly assigned to course dates. However, 53 students assigned to courses in November and December 2020, were not able to go bedside due to contact restrictions. These students formed the interventional group and the remaining 49 students the control group. The primary outcome measures were students’ overall grading of the course (school grades, 1–6) as well as ratings of knowledge and skills provided by the students themselves and their lecturers on a numerical rating scale (0–10). Comparison between groups was performed using frequentist and Bayesian t-statistics. Results The teaching format without patient contact received a significantly poorer overall grade by the students (p = 0.018). However, improvements in the students’ self-ratings of knowledge and skills did not differ between the two formats (all p > 0.05, BF10max = 0.42). Moreover, especially practical skills were even rated significantly better in the group without patient contact by the lecturers (p