116 research outputs found
Homogeneity assessment of Swiss snow depth series: comparison of break detection capabilities of (semi-)automatic homogenization methods
Identifying Reactive Sites and Surface Traps in Chalcopyrite Photocathodes
Gathering information on the atomic nature of reactive sites and trap states is key to fine tuning catalysis and suppressing deleterious surface voltage losses in photoelectrochemical technologies. Here, spectroelectrochemical and computational methods were combined to investigate a model photocathode from the promising chalcopyrite family: CuIn0.3Ga0.7S2. We found that voltage losses are linked to traps induced by surface Ga and In vacancies, whereas operando Raman spectroscopy revealed that catalysis occurred at Ga, In, and S sites. This study allows establishing a bridge between the chalcopyrite's performance and its surface's chemistry, where avoiding formation of Ga and In vacancies is crucial for achieving high activity.This work was supported by the Swiss National Science Foundation (SNSF) under the Ambizione Energy grant (PZENP2_166871) and by the Gaznat-EPFL Research Program. M.B. and U.A. were supported by the Swiss National Science Foundation Professorship Grants PP00P2_157615 and PP00P2_187185. Calculations were performed on UBELIX, the HPC cluster at the University of Bern. M.X. is grateful for the support from the China Scholarship Council (No. CSC201806160172) and the Strategic JapaneseâSwiss Science and Technology program (514259). Open access funding provided by Ecole Polytechnique Federale de Lausanne
Renal Function but Not Asymmetric Dimethylarginine Is Independently Associated with Retinopathy in Type 2 Diabetes
Background. Asymmetric dimethylarginine (ADMA) is associated with macrovascular disease and possibly with microangiopathy in type 2 diabetes (T2DM). We tested the hypothesis that ADMA is related to diabetic retinopathy (DR) independently of macrovascular disease. Methods. This cross-sectional study included 127 T2DM patients selected to achieve equal distributions of patients with and without macrovascular disease in the groups with and without DR. Results. Patients with DR had increased ADMA, longer diabetes duration, and reduced glomerular filtration rate (GFR). ADMA correlated with GFR (Ï = -0.35; P < .001), diabetes duration (Ï = 0.19; P = .048), and age (Ï = 0.19; P = .033). Logistic regression analysis revealed an association of ADMA with DR. After adjustment for macrovascular disease, this association remained significant (OR 1.48; 95% CI:â1.02â2.15; P = .039). Inclusion of GFR and T2DM duration into the model abolished this significant relationship. GFR remained the only independent predictor for DR. A 10âmL/min/1.73âm2 GFR decrease was associated with DR in a multivariate model (OR 1.30; 95% CI:â1.08â1.56; P = .006). Conclusions. These findings indicate an association between ADMA and DR in T2DM independent of macrovascular disease. This relationship is modified by GFR, the only parameter significantly related to DR in multivariate analysis
Strong signature of electron-vibration coupling in molecules on Ag(111) triggered by tip-gated discharging
Abstract Electron-vibration coupling is of critical importance for the development of molecular electronics, spintronics, and quantum technologies, as it affects transport properties and spin dynamics. The control over charge-state transitions and subsequent molecular vibrations using scanning tunneling microscopy typically requires the use of a decoupling layer. Here we show the vibronic excitations of tetrabromotetraazapyrene (TBTAP) molecules directly adsorbed on Ag(111) into an orientational glassy phase. The electron-deficient TBTAP is singly-occupied by an electron donated from the substrate, resulting in a spin 1/2 state, which is confirmed by a Kondo resonance. The TBTAPâąâ discharge is controlled by tip-gating and leads to a series of peaks in scanning tunneling spectroscopy. These occurrences are explained by combining a double-barrier tunneling junction with a Franck-Condon model including molecular vibrational modes. This work demonstrates that suitable precursor design enables gate-dependent vibrational excitations of molecules on a metal, thereby providing a method to investigate electron-vibration coupling in molecular assemblies without a decoupling layer
Identifizierung von reaktiven Zentren und OberflÀchenfallen in Chalkopyrit-Photokathoden
Das Sammeln von Informationen ĂŒber die atomare Natur von reaktiven Zentren und FallenzustĂ€nden ist der SchlĂŒssel zur Feinabstimmung der Katalyse und zur UnterdrĂŒckung schĂ€dlicher OberflĂ€chenpotentialverluste in photoelektrochemischen Technologien. Hier wurden spektroelektrochemische und rechnerische Methoden kombiniert, um eine Modellphotokathode aus der vielversprechenden Chalkopyrit-Familie zu untersuchen: CuIn0.3Ga0.7S2. Es wurde festgestellt, dass Potentialverluste mit Fallen verbunden sind, die durch OberflĂ€chen-Ga- und In-Leerstellen induziert werden, wohingegen Operando-Raman-Spektroskopie zeigte, dass Katalyse an Ga-, In- und S-Stellen stattfand. Diese Studie ermöglicht es, eine BrĂŒcke zwischen der Leistung des Chalkopyrits und seiner OberflĂ€chenchemie zu schlagen, wobei die Vermeidung der Bildung von Ga- und In-Leerstellen entscheidend ist, um eine hohe AktivitĂ€t zu erzielen.Diese Arbeit wurde vom Schweizerischen Nationalfonds (SNF) im Rahmen des Ambizione Energy Grant (PZENP2_166871) und vom Gaznat-EPFL Forschungsprogramm unterstĂŒtzt. M.B. und U.A. wurden durch die Förderungsprofessuren PP00P2_157615 und PP00P2_187185 des Schweizerischen Nationalfonds unterstĂŒtzt. Die Berechnungen wurden auf UBELIX, dem HPC-Cluster der UniversitĂ€t Bern, durchgefĂŒhrt. M.X. dankt dem China Scholarship Council (Nr. CSC201806160172) und dem Strategic JapaneseâSwiss Science and Technology-Programm (514259) fĂŒr die UnterstĂŒtzung. Open access funding provided by Ecole Polytechnique Federale de Lausanne
Rare Copy Number Variants in \u3cem\u3eNRXN1\u3c/em\u3e and \u3cem\u3eCNTN6\u3c/em\u3e Increase Risk for Tourette Syndrome
Tourette syndrome (TS) is a model neuropsychiatric disorder thought to arise from abnormal development and/or maintenance of cortico-striato-thalamo-cortical circuits. TS is highly heritable, but its underlying genetic causes are still elusive, and no genome-wide significant loci have been discovered to date. We analyzed a European ancestry sample of 2,434 TS cases and 4,093 ancestry-matched controls for rare (\u3c 1% frequency) copy-number variants (CNVs) using SNP microarray data. We observed an enrichment of global CNV burden that was prominent for large (\u3e 1 Mb), singleton events (OR = 2.28, 95% CI [1.39â3.79], p = 1.2 Ă 10â3) and known, pathogenic CNVs (OR = 3.03 [1.85â5.07], p = 1.5 Ă 10â5). We also identified two individual, genome-wide significant loci, each conferring a substantial increase in TS risk (NRXN1 deletions, OR = 20.3, 95% CI [2.6â156.2]; CNTN6 duplications, OR = 10.1, 95% CI [2.3â45.4]). Approximately 1% of TS cases carry one of these CNVs, indicating that rare structural variation contributes significantly to the genetic architecture of TS
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