613 research outputs found
Komani (Dalmace, Albanie). Bilan de la mission franco-albanaise de la campagne 2017
No full textLa mission de terrain à Komani a été menée du 28 juillet au 30 août 2017, avec une équipe de 26 spécialistes et étudiants et d’une vingtaine d’ouvriers. Cinq spécialistes chargés de l’étude du mobilier anthropologique, des petits objets et de la restauration ont séjourné et travaillé sur place. La mission a réuni H. Sokoli (archéologue, Directorat régional de la culture nationale de Shkodra), D. Rosselet-Christ, A. Bridy, G. Binovec, L. Anchieri (étudiants en master en archéologie préhistoriq..
Valeur diagnostique et thérapeutique de l'insufflation et de l'hystérosalpingographie dans la stérilité
No full textBeneficial effects of L-canavanine, a selective inhibitor of inducible nitric oxide synthase, during rodent endotoxaemia.
No full text1. The cardiovascular failure in sepsis may result from increased nitric oxide biosynthesis, through the diffuse expression of an inducible nitric oxide synthase. In such conditions, nitric oxide synthase inhibitors might be of therapeutic value, but detrimental side effects have been reported with their use, possibly related to the blockade of constitutive nitric oxide synthase. Therefore, the use of selective inhibitors of inducible nitric oxide synthase might be more suitable. The aim of this study was to evaluate the effects of L-canavanine, a potentially selective inhibitor of inducible nitric oxide synthase, in an animal model of septic shock. 2. Anaesthetized rats were challenged with 10 mg/kg lipopolysaccharide intravenously. One hour later, they randomly received a 5 h infusion of either L-canavanine (20 mg h-1 kg-1, n = 15), nitro-L-arginine methyl ester (5 mg h-1 kg-1, n = 13) or 0.9% NaCl (2 ml h-1 kg-1, n = 21). Lipopolysaccharide induced a progressive fall in blood pressure and cardiac index, accompanied by a significant lactic acidosis and a marked rise in plasma nitrate. All these changes were significantly attenuated by L-canavanine, which also improved the tolerance of endotoxaemic animals to acute episodes of hypovolaemia. In addition, L-canavanine significantly increased survival of mice challenged with a lethal dose of lipopolysaccharide. In contrast to L-canavanine, nitro-L-arginine methyl ester increased blood pressure at the expense of a severe fall in cardiac index, while largely enhancing lactic acidosis. This agent did not improve survival of endotoxaemic mice. In additional experiments, we found that the pressor effect of L-canavanine in advanced endotoxaemia (4 h) was reversed by L-arginine, confirming that it was related to nitric oxide synthase inhibition. In contrast, L-canavanine did not exert any influence on blood pressure in the very early stage (first hour) of endotoxaemia or in the absence of lipopolysaccharide exposure, indicating a lack of constitutive nitric oxide synthase inhibition by this agent. 3. In conclusion, L-canavanine produced beneficial haemodynamic and metabolic effects and improved survival in rodent endotoxic shock. The actions of L-canavanine were associated with a selective inhibition of inducible nitric oxide synthase and were in marked contrast to the deleterious consequences of nitro-L-arginine methyl ester, a non-selective nitric oxide synthase inhibitor, in similar conditions
Diffusion of meropenem and imipenem through the outer membrane of Escherichia coli K-12 and correlation with their antibacterial activities
No full textThe outer membrane permeability to meropenem and imipenem in Escherichia coli K-12 was investigated, and its porin-deficient mutants were transformed with a constructed vector carrying the carbapenem-hydrolyzing CphA metallo-beta-lactamase gene. By using the method of Zimmermann and Rosselet, meropenem was shown to penetrate through the outer membrane of E. coli K-12 five times faster than cephaloridine but twice as slowly as imipenem. Lack of one or both porins significantly reduced the penetration of both carbapenems. No evidence of specific porin pathways of the type described in Pseudomonas aeruginosa was found. Despite its slower penetration, meropenem was two to eight times more active than imipenem against both parent and porin-defective mutants, whether harbouring CphA beta-lactamase or not. Meropenem was also more active than imipenem against E. coli DC2, a strain with a breakdown in the outer membrane permeability which made periplasmic concentrations of beta-lactams similar to the external con
The Heavy-Ion Physics Programme with the ATLAS Detector
No full textThe CERN LHC will collide lead ions at sqrt(s)=5.5 TeV per nucleon pair and will provide crucial information about the formation of a quark gluon plasma at the highest temperatures and densities ever created in the laboratory. We report on an updated evaluation of the ATLAS potential to study heavy-ion physics. The ATLAS detector will perform especially well for high pT phenomena even in the presence of the high-multiplicity soft background expected from lead-lead collisions, and most of the detector subsystems retain their nearly full capability. ATLAS will study a full range of observables which characterize the hot and dense medium formed in heavy-ion collisions. In addition to global measurements such as particle multiplicities and collective flow, heavy-quarkonia suppression, jet quenching and the modification of jets passing in the dense medium will be accessible to ATLAS. ATLAS will also study forward physics and ultraperipheral collisions using Zero Degree Calorimeters
Large Acceptance Measurement of Photons and Charged Particles in Heavy Ion Reactions
No full text% WA98 \\ \\ The aim of the experiment is the high statistics study of photons and neutral hadrons, as well as of charged particles, and their correlations in Pb~-~Pb collisions. The photons are measured by: \begin{enumerate}[-] \item a 10~000 module LEADGLASS SPECTROMETER yielding high precision data on and at midrapidity (with transverse momenta 0.3 GeV/c p 4.5 GeV/c for and 1.5~GeV/c~~p ~4.0~GeV/c for covering the thermal as well as the hard scattering regime beyond 3~GeV/c) and determination of the thermal and direct photon to ratio. \item a pad preshower PHOTON MULTIPLICITY DETECTOR which, by comparing with the charged particle multiplicity measurement allows to determine the photon enrichment in an event or event class. \end{enumerate}\\ \\The charged particle setup contains:\\ \\\begin{enumerate}[-] \item a 4000 element SILICON PAD DETECTOR and a 4-inch SILICON DRIFT DETECTOR to measure the charged particle multiplicity. \item a MULTISTEP AVALANCHE TRACKING SYSTEM with optical readout for momentum measurement of negative tracks. \item a MULTISTEP AVALANCHE TRACKING SYSTEM with pad readout for momentum measurement of positive tracks. \item a TIME-OF-FLIGHT SYSTEM for each tracking system for particle identification. \end{enumerate} \\ \\This allows to correlate electromagnetic and charged hadronic data within event classes and to yield high statistics transverse momentum spectra of identified hadrons as well as Bose-Einstein correlation data
Quarkonia Physics in Heavy-Ion collisions with the ATLAS Detector
No full textUpdated evaluation of the ATLAS capabilities to study heavy quarkonia physics in Pb+Pb collisions
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