51 research outputs found

    A Novel Acyl-CoA Beta-Transaminase Characterized from a Metagenome

    Get PDF
    BACKGROUND: Bacteria are key components in all ecosystems. However, our knowledge of bacterial metabolism is based solely on the study of cultivated organisms which represent just a tiny fraction of microbial diversity. To access new enzymatic reactions and new or alternative pathways, we investigated bacterial metabolism through analyses of uncultivated bacterial consortia. METHODOLOGY/PRINCIPAL FINDINGS: We applied the gene context approach to assembled sequences of the metagenome of the anaerobic digester of a municipal wastewater treatment plant, and identified a new gene which may participate in an alternative pathway of lysine fermentation. CONCLUSIONS: We characterized a novel, unique aminotransferase that acts exclusively on Coenzyme A (CoA) esters, and proposed a variant route for lysine fermentation. Results suggest that most of the lysine fermenting organisms use this new pathway in the digester. Its presence in organisms representative of two distinct bacterial divisions indicate that it may also be present in other organisms

    Value of ultrasonography as a marker of early response to abatacept in patients with rheumatoid arthritis and an inadequate response to methotrexate: results from the APPRAISE study

    Get PDF
    Objectives: To study the responsiveness of a combined power Doppler and greyscale ultrasound (PDUS) score for assessing synovitis in biologic-naïve patients with rheumatoid arthritis (RA) starting abatacept plus methotrexate (MTX). Methods: In this open-label, multicentre, single-arm study, patients with RA (MTX inadequate responders) received intravenous abatacept (∼10 mg/kg) plus MTX for 24 weeks. A composite PDUS synovitis score, developed by the Outcome Measures in Rheumatology–European League Against Rheumatism (OMERACT–EULAR)-Ultrasound Task Force, was used to evaluate individual joints. The maximal score of each joint was added into a Global OMERACT–EULAR Synovitis Score (GLOESS) for bilateral metacarpophalangeal joints (MCPs) 2–5 (primary objective). The value of GLOESS containing other joint sets was explored, along with clinical efficacy. Results: Eighty-nine patients completed the 24-week treatment period. The earliest PDUS sign of improvement in synovitis was at week 1 (mean change in GLOESS (MCPs 2–5): −0.7 (95% CIs −1.2 to −0.1)), with continuous improvement to week 24. Early improvement was observed in the component scores (power Doppler signal at week 1, synovial hyperplasia at week 2, joint effusion at week 4). Comparable changes were observed for 22 paired joints and minimal joint subsets. Mean Disease Activity Score 28 (C reactive protein) was significantly reduced from weeks 1 to 24, reaching clinical meaningful improvement (change ≥1.2) at week 8. Conclusions: In this first international prospective study, the composite PDUS score is responsive to abatacept. GLOESS demonstrated the rapid onset of action of abatacept, regardless of the number of joints examined. Ultrasound is an objective tool to monitor patients with RA under treatment. Trial registration number: NCT00767325

    RESISTANCE D'ASSEMBLAGES DE TYPE TIGE EN STRUCTURE BOIS SOUS CHARGEMENTS CYCLIQUES COMPLEXES

    No full text
    DANS LES STRUCTURES BOIS MODERNES, L'ENERGIE SISMIQUE OU EOLIENNE EST ESSENTIELLEMENT DISSIPEE DANS LES ASSEMBLAGES. CES CHARGEMENTS, ENTRE ETAT DE SERVICE ET ULTIME, PEUVENT INDUIRE DES VARIATIONS DES CARACTERISTIQUES MECANIQUES ULTIMES (RESISTANCE, RIGIDITE) QUI DOIVENT ETRE REACTUALISEES. LA RESISTANCE CYCLIQUE PEUT ETRE DIMINUEE PAR ENDOMMAGEMENT. INVERSEMENT, DES CHARGEMENTS PROGRESSIFS PEUVENT INDUIRE UN GAIN DE RESISTANCE GLOBALE PAR MODIFICATION PROGRESSIVE DES CARACTERISTIQUES DE PORTANCE A L'INTERFACE (CONSOLIDATION). CES VARIATIONS, APRES CHARGEMENTS CYCLIQUES, SONT ETUDIEES EXPERIMENTALEMENT. LA RESISTANCE RESIDUELLE DE 450 EPROUVETTES D'ENFONCEMENT, AVEC UN DIAMETRE DE TIGE DE 14 MM ET TROIS ETATS DE SURFACE, EST MESUREE. LES SIGNAUX ONDULES EN FORCE (1 HZ) SONT COMPOSES DE PLUSIEURS SEQUENCES A DIFFERENTS NIVEAUX DE CHARGE (DE 0,3 A 0,95) ET D'UN NOMBRE DE CYCLES VARIABLES (DE 1 A 90). LA RESISTANCE MAXIMALE EST ATTEINTE SOUS CHARGEMENT MONOTONE ET COMPAREE A CELLE DE L'EPROUVETTE DE REFERENCE. POUR UNE PRECISION DE JUMELAGE DE 2%, LES VARIATIONS DE RR ATTEIGNENT 10%. ELLES DEPENDENT DE TOUTES LES CARACTERISTIQUES DU CHARGEMENT. LES CHARGEMENTS LES PLUS LONGS ET INTENSES NE SONT PAS FORCEMENT LES PLUS ENDOMMAGEANTS. POUR UN CHARGEMENT COMPLET, L'EVOLUTION DES VITESSES DE DEPLACEMENTS CYCLIQUES (PHASES PRIMAIRE ET SECONDAIRE) PEUT ETRE RELIEE A L'APPARITION COMBINEE D'ENDOMMAGEMENT ET DE CONSOLIDATION. UN MODELE RHEOLOGIQUE A 3 PARAMETRES INTEGRANT DES COMPORTEMENTS ELASTIQUE, PLASTIQUE ET VISQUEUX, EST DEVELOPPE AFIN D'ANALYSER CES DEPLACEMENTS CYCLIQUES. LES DEPLACEMENTS GLOBAUX ET LES PHENOMENES D'ACCOMMODATION OBSERVES SONT RETROUVES. LES VARIATIONS DE RIGIDITE PLASTIQUE, ASSOCIEE A UNE FONCTION CONTINUE NON LINEAIRE, PEUVENT ETRE RELIEES A LA RESISTANCE ET PERMETTENT DE PROPOSER UNE REACTUALISATION DE LA COURBE ENVELOPPE.CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocNANCY/VANDOEUVRE-INPL (545472102) / SudocSudocFranceF

    Diagnostic et analyse de risques liés au vieillissement des barrages (Développement de méthodes d'aide à l'expertise)

    No full text
    CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

    ANALYSE ET MODELISATION DE LA RUPTURE DUCTILE PAR DES MODELES MICROMECANIQUES FONDES SUR L'APPROCHE LOCALE

    No full text
    CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

    Synthèse d ondes électriques picosecondes de puissance par commutation optoélectronique (application aux radars à bande spectrale ultralarge)

    No full text
    Le but de cette thèse a été la réalisation d un démonstrateur de radar ultralarge bande multi-sources. Ce radar repose sur la réalisation de générateurs optoélectroniques délivrant des impulsions électriques de forte puissance à spectre ultralarge et parfaitement synchronisables. Cela a été rendu possible par le transfert d une technologie issue du CEA vers notre laboratoire. Les travaux réalisés ont conduit vers une architecture permettant d obtenir des impulsions avec des performances accrues (<300ps pour 11kV crête). Ils ont permis de dégager un modèle comportemental hyperfréquence des générateurs et leurs réactions aux paramètres des commandes optiques et électriques. Une technique innovante de diminution de la durée des impulsions optiques issues d une source laser nanoseconde a également été développée. La démonstration du concept multi-sources permettant la validation du concept d agilité en terme de basculement du front d onde fait de ce système un outil unique et innovant.This thesis was dedicated to the realisation of ultra wide band antenna array radar. This detection system is based on the use of optoelectronic generators. These generators must be able to deliver high power electrical synchronised pulses with an ultra wide band spectrum. This work was based on transfer of Atomic Energy Commission's technology to our laboratory. Temporal and power improvements were the main results ofthis research (<300ps duration for 11kV of peak voltage). AlI these studies led to the development of a propagation behaviour model ofgenerators and a better understanding ofoptical and electrical command's implications on generated signaIs. The coherent combination of the output power emitted by a one dimension antenna array was demonstrated. Moreover, a new optical picosecond source based on pulse chapping process was demonstrated and patented.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF
    • …
    corecore