Influence de la teneur en oxygène sur la microstructure et le comportement mécanique de la phase « ex bêta » résultant de l'oxydation à haute température (1000-1200°C) du zircaloy 4

International audienceL'étude ici illustrée s'intéresse au comportement thermo - métallurgique - mécanique des alliages de Zr des tubes de gainage du combustible des Réacteurs nucléaires à Eau Pressurisée (REP), lors de transitoires à hautes températures (HT) en ambiance vapeur d'eau, simulant des conditions hypothétiques accidentelles (dites APRP). Il apparaît intéressant d'approfondir la connaissance des phénomènes métallurgiques et thermomécaniques mis en jeu lors de tels transitoires, en particulier vis-à-vis du comportement mécanique résiduel « post oxydation trempe ». Différentes teneurs en oxygène ont été incorporées dans l'alliage étudié, pour simuler la diffusion de cet élément dans le substrat métallique qui intervient lors de l'oxydation HT. Des caractérisations microstructurales par EBSD, MET, MEB... et des caractérisations mécaniques par essai de traction, mesures de constantes physiques... ont permis de décrire la microstructure et le comportement mécanique de la phase résiduelle la plus ductile – phase dite « ex-bêta » - résultant de l'oxydation HT des gaines en zircaloy-4

"It doesn't do any harm, but patients feel better": a qualitative exploratory study on gastroenterologists' perspectives on the role of antidepressants in inflammatory bowel disease

Background: Interest in psychological factors in patients with inflammatory bowel disease (IBD) has increased in recent years. It has even been proposed that treating psychological co-morbidities with antidepressants may control disease activity and improve quality of life. Despite this, there is no data on gastroenterologists' attitudes to, and experiences with, antidepressant therapy in patients with IBD. Methods: We conducted semi-structured interviews with 18 gastroenterologists associated with metropolitan teaching hospitals. Qualitative content analysis was used to examine their responses. Results: Seventy-eight percent of gastroenterologists had treated IBD patients with antidepressants for pain, depression and/or anxiety, and insomnia. Antidepressants were reported to be useful in improving psychosocial well-being, quality of life, and self-management of the disease by patients. However, in this group of gastroenterologists, there appears to be skepticism towards psychological disorders themselves or antidepressant therapy having a central role in either the causation of IBD or its clinical course. Nevertheless, these gastroenterologists were receptive to the idea of conducting a trial of the role of antidepressants in IBD. Conclusion: While the majority of specialists have treated IBD patients with antidepressants, there is considerable skepticism with regard to efficacy of antidepressive therapy or the role of psychological factors in the outcome of IBD patients.Antonina A Mikocka-Walus, Deborah A Turnbull, Nicole T Moulding, Ian G Wilson, Jane M Andrews and Gerald J Holtman

Crossroads: A Shifting Landscape

Catalog for the exhibition Crossroads: A Shifting Landscape held at the Seton Hall University Walsh Gallery, January 17 - February 17, 2012. Curated by Jesse Gordon and Emily Ozga. Includes an essay by Jesse Gordon and Emily Ozga. Includes color illustrations

Is early endoscopy in the emergency room beneficial in patients with bleeding peptic ulcer? A " fortuitously controlled " study

BACKGROUND AND STUDY AIMS: In previous randomized trials, early endoscopy improved the outcome in patients with bleeding peptic ulcer, though most of these studies defined "early" as endoscopy performed within 24 hours after admission. Using the length of hospital stay as the primary criterion for the clinical outcome, we compared the results of endoscopy done immediately after admission (early endoscopy in the emergency room, EEE) with endoscopy postponed to a time within the first 24 hours after hospitalization, but still during normal working hours ("delayed" endoscopy in the endoscopy unit, DEU). PATIENTS AND METHODS: We conducted a retrospective analysis of data from 81 consecutive patients with bleeding peptic ulcer admitted in 1997 and 1998 (age range 16 - 90 years). Of these 81 patients, 38 underwent DEU (the standard therapy at the hospital) and 43 underwent EEE. Patients in the two groups were comparable with regard to admission criteria, were equally distributed with respect to their risk of adverse outcome (assessed using the Baylor bleeding score and the Rockall score), and differed only in the treatment they received. Endoscopic hemostasis was performed whenever possible in all patients with Forrest types I, IIa, and IIb ulcer bleeding. RESULTS: We found similar rates in the two groups for recurrent bleeding (16 % in DEU patients vs. 14 % in EEE patients), persistent bleeding (8 % in DEU patients vs. none in EEE patients), medical complications (21 % in DEU patients vs. 26 % in EEE patients), the need for surgery (8 % in DEU patients vs. 9 % in EEE patients), and the length of hospital stay (5.1 days for DEU patients vs. 5.9 days for EEE patients). None of the differences between the two groups in these parameters were statistically significant. None of the patients died. CONCLUSIONS: Early endoscopy in an emergency room did not improve the clinical outcome in our 81 consecutive patients with bleeding peptic ulcer