Generation of Matrix Degradation Products Using an In Vitro MMP Cleavage Assay.

Matrix metalloproteinases (MMPs) play crucial roles in tissue homeostasis and pathologies by remodeling the extracellular matrix. Previous studies have demonstrated the biological activities of MMP-derived cleavage products. Furthermore, specific fragments can serve as biomarkers. Therefore, an in vitro cleavage assay to identify substrates and characterize cleavage patterns could provide important insight in disease-relevant mechanisms and the identification of novel biomarkers. In the pathogenesis of osteoarthritis (OA), MMP-2, -8, -9 and -13 are of vital importance. However, it is unclear which protease can cleave which matrix component. To address this question, we established an in vitro cleavage assay using recombinantly expressed MMPs and the two cartilage matrix components, COMP and thrombospondin-4. We found a time- and concentration-dependent degradation and an MMP-specific cleavage pattern for both proteins. Cleavage products can now be enriched and purified to investigate their biological activity. To verify the in vivo relevance, we compared the in vitro cleavage patterns with serum and synovial fluid from OA patients and could indeed detect fragments of similar size in the human samples. The cleavage assay can be adapted to other MMPs and substrates, making it a valuable tool for many research fields.

Resistivity Exponents in 3D Dirac Semimetals From Electron-Electron Interaction.

We study the resistivity of three-dimensional semimetals with linear dispersion in the presence of on-site electron-electron interaction. The well-known quadratic temperature dependence of the resistivity of conventional metals is turned into an unusual T^{6} behavior. An analogous change affects the thermal transport, preserving the linearity in T of the ratio between thermal and electrical conductivities. These results hold from weak coupling up to the nonperturbative region of the Mott transition. Our findings yield a natural explanation for the hitherto not understood large exponents characterizing the temperature dependence of transport experiments on various topological semimetals.

Two-year analysis of dermatological out-of-hours consultations at Frankfurt University Hospital.

BACKGROUND: In recent years, emergency consultations have become more common in all medical disciplines. In Germany, dermatological out-of-hours consultations are handled by emergency practices, emergency departments and tertiary care providers. Little information is available on the reasons for these dermatological consultations. OBJECTIVES: The aim of this study was to analyze patient characteristics, diagnoses and admission rates resulting from these consultations. METHODS: We conducted a retrospective study covering two years of out-of-hours consultations at a dermatological tertiary referral center. RESULTS: A total of 3635 patients presented at the referral center. The most frequent outpatient diagnoses were acute urticaria (13.8 %) and bacterial infections (12.3 %). 83 % of the outpatient diagnoses required the most advanced competence level according to the new German curriculum for undergraduate education of medical students. 405 (11.01 %) patients did not require dermatological treatment, and 430 patients (13.6 %) were admitted to hospital. Most admissions were due to bacterial infections and herpes zoster. Advanced age, pain and fever were associated with a relatively high risk of admission. CONCLUSIONS: Admission rates at the dermatological tertiary referral center were substantially lower than at interdisciplinary emergency departments. A few diagnoses accounted for more than half of all consultations. These diagnoses are well represented within the new German curriculum.

Volatility impacts on the European banking sector: GFC and COVID-19.

This paper analyses the volatility transmission between European Global Systematically Important Banks (GSIBs) and implied stock market volatility. A Dynamic Conditional Correlation Generalized Autoregressive Conditional Heteroskedasticity model is applied to determine the dynamic correlation between returns of Europe's GSIBs and the world's most prominent measure of market "fear", the CBOE Volatility Index (VIX). The results identify a higher negative co-relationship between the VIX and GSIB returns during the COVID-19 period compared with the Global Financial Crisis (GFC), with one-day lagged changes in the VIX negatively Granger-causing bank returns. The asymmetric impact of changes in implied volatility is examined by quantile regressions, with the findings showing that in the lower quartile-where extreme negative bank returns are present-jumps in the VIX are highly significant. This effect is more pronounced during COVID-19 than during the GFC. Additional robustness analysis shows that these findings are consistent during the periods of the Swine Flu and Zika virus epidemics.

Correction to: Volatility impacts on the European banking sector: GFC and COVID-19.

[This corrects the article DOI: 10.1007/s10479-022-04523-8.].