Étude expérimentale et théorique du butanethiol absorbé sur une surface Au(111)

Depuis le début des années 80, il est connu que les alcanethiols peuvent se chimisorber sur une surface d'or et ainsi former des monocouches auto-organisées. Dans ce travail, nous avons étudié les propriétés de la monocouche de butanethiol adsorbées sur une surface d'or par microscopie à effet tunnel, par simulation spectrale et simulations de dynamique moléculaire. La microscopie à effet tunnel ex-situ permet de connaître la structure que prennent les molécules à la surface de l'or et d'observer cette structure en fonction du temps (plusieurs semaines), tandis que la microscopie à effet tunnel en temps réel, in-situ, nous permet d'observer la formation de la monocouche à la surface de l'or. Les simulations spectrales indiquent l'orientation moléculaire des chaînes du butanethiol à partir de son spectre infrarouge, tandis que les simulations de dynamique moléculaire permettent de comparer les interactions en jeu dans l'auto-organisation des chaînes courtes comme le butanethiol et des chaînes longues d'alcanethiols."--Résumé abrégé par UM

What lies at the intersection of law and psychiatric nursing? Exploring the process of judiciarization in the context of mental health

In this article, our aim is to provide a critical analysis of the phenomenon of judiciarization of people suffering from a mental illness and its impact on nursing practice. To explore the issues inherent to this phenomenon, we employed the methodology of discursive analysis greatly inspired by the work of French philosopher Michel Foucault. The results of this analysis push our reflection on the experiences and practices that take place at the psychiatric and judicial interface, engaging in a critic of underlying goals of public protection, social control, and coercion being incorporated to nursing practice. While acting in seemingly humanistic and therapeutic roles of care, nurses are simultaneously and inevitably fulfilling a mandate to social control which, to date, remains relatively under documented

The Alestle - Vol. 57 No. 1 - 08/24/2004

Vol. 57 No.

Extant diversity of bryophytes emerged from successive post-Mesozoic diversification bursts

Unraveling the macroevolutionary history of bryophytes, which arose soon after the origin of land plants but exhibit substantially lower species richness than the more recently derived angiosperms, has been challenged by the scarce fossil record. Here we demonstrate that overall estimates of net species diversification are approximately half those reported in ferns and similar to 30% those described for angiosperms. Nevertheless, statistical rate analyses on time-calibrated large-scale phylogenies reveal that mosses and liverworts underwent bursts of diversification since the mid-Mesozoic. The diversification rates further increase in specific lineages towards the Cenozoic to reach, in the most recently derived lineages, values that are comparable to those reported in angiosperms. This suggests that low diversification rates do not fully account for current patterns of bryophyte species richness, and we hypothesize that, as in gymnosperms, the low extant bryophyte species richness also results from massive extinctions.Assembling the Tree of Life programme at NSF; NSF [EF-0531730-002, EF-0531680, EF-0531750]; Scottish Government's Rural and Environment Science and Analytical Services Division; BeiPD-cofund Marie Curie fellowshipinfo:eu-repo/semantics/publishedVersio

A new inhibitor of the β-arrestin/AP2 endocytic complex reveals interplay between GPCR internalization and signalling.

AbstractIn addition to G protein-coupled receptor (GPCR) desensitization and endocytosis, β-arrestin recruitment to ligand-stimulated GPCRs promotes non-canonical signalling cascades. Distinguishing the respective contributions of β-arrestin recruitment to the receptor and β-arrestin-promoted endocytosis in propagating receptor signalling has been limited by the lack of selective analytical tools. Here, using a combination of virtual screening and cell-based assays, we have identified a small molecule that selectively inhibits the interaction between β-arrestin and the β2-adaptin subunit of the clathrin adaptor protein AP2 without interfering with the formation of receptor/β-arrestin complexes. This selective β-arrestin/β2-adaptin inhibitor (Barbadin) blocks agonist-promoted endocytosis of the prototypical β2-adrenergic (β2AR), V2-vasopressin (V2R) and angiotensin-II type-1 (AT1R) receptors, but does not affect β-arrestin-independent (transferrin) or AP2-independent (endothelin-A) receptor internalization. Interestingly, Barbadin fully blocks V2R-stimulated ERK1/2 activation and blunts cAMP accumulation promoted by both V2R and β2AR, supporting the concept of β-arrestin/AP2-dependent signalling for both G protein-dependent and -independent pathways.</jats:p

Chemical composition of nanoporous layer formed by electrochemical etching of p-type GaAs

Abstract : We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer showed a major decrease in the CL intensity and a change in chemical composition and in the crystalline phase. Contrary to previous reports on p-GaAs porosification, which stated that the formed layer is composed of porous GaAs, we report evidence that the porous layer is in fact mainly constituted of porous As2O3. Finally, a qualitative model is proposed to explain the porous As2O3 layer formation on p-GaAs substrate

ERS: A simple scoring system to predict early recurrence after surgical resection for hepatocellular carcinoma.

peer reviewed[en] BACKGROUND: Surgical resection (SR) is a potentially curative treatment of hepatocellular carcinoma (HCC) hampered by high rates of recurrence. New drugs are tested in the adjuvant setting, but standardised risk stratification tools of HCC recurrence are lacking. OBJECTIVES: To develop and validate a simple scoring system to predict 2-year recurrence after SR for HCC. METHODS: 2359 treatment-naïve patients who underwent SR for HCC in 17 centres in Europe and Asia between 2004 and 2017 were divided into a development (DS; n = 1558) and validation set (VS; n = 801) by random sampling of participating centres. The Early Recurrence Score (ERS) was generated using variables associated with 2-year recurrence in the DS and validated in the VS. RESULTS: Variables associated with 2-year recurrence in the DS were (with associated points) alpha-fetoprotein (100: 3), size of largest nodule (≥40 mm: 1), multifocality (yes: 2), satellite nodules (yes: 2), vascular invasion (yes: 1) and surgical margin (positive R1: 2). The sum of points provided a score ranging from 0 to 11, allowing stratification into four levels of 2-year recurrence risk (Wolbers' C-indices 66.8% DS and 68.4% VS), with excellent calibration according to risk categories. Wolber's and Harrell's C-indices apparent values were systematically higher for ERS when compared to Early Recurrence After Surgery for Liver tumour post-operative model to predict time to early recurrence or recurrence-free survival. CONCLUSIONS: ERS is a user-friendly staging system identifying four levels of early recurrence risk after SR and a robust tool to design personalised surveillance strategies and adjuvant therapy trials

Ag Diffusion Control Through Sn on a Sequential Plating-Based Bumping Process

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