57 research outputs found

    ÉVALUATION IN-VITRO DE L’ACTIVITÉ ANTIBACTERIENNE DES EXTRAITS NATURELS D'UNE SOUS ESPECE DE TEUCRIUM POLIUM L. CULTIVÉE DANS LA RÉGION DE BENI SOUIK, BISKRA

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    Ce travail est une contribution Ă  la valorisation des plantes mĂ©dicinales utilisĂ©es en mĂ©decine traditionnelle. Il a pour objectifs la recherche et l’étude de nouveaux agents antibactĂ©riens issus de la plante mĂ©dicinale trĂšs utilisĂ©e par la population algĂ©rienne, Teucrium Polium L. sous espĂšce thymoĂŻdes de la famille Lamiaceae, cultivĂ©e dans la rĂ©gion Beni souik de la wilaya de Biskra. L'extraction a Ă©tĂ© rĂ©alisĂ©e sur la partie aĂ©rienne de la plante, on utilisant des solvants de polaritĂ© croissante, ce qui nous a permis d'obtenir les flavonoĂŻdes. L’huile essentielle a Ă©tĂ© rĂ©cupĂ©rĂ©e par une hydrodistillation. L’activitĂ© antibactĂ©rienne des extraits prĂ©parĂ©s a Ă©tĂ© Ă©valuĂ©e in vitro en utilisant l’antibiogramme standard et la micro-dilution en milieu liquide ; vis Ă  vis trois souches bactĂ©riennes de rĂ©fĂ©rence. Les deux souches bactĂ©riennes testĂ©es Pseudomonas aeruginosa et Escherichia coli se sont rĂ©vĂ©lĂ©es insensibles aux extraits de flavonoĂŻdes et l’huile essentielle de Teucrium Polium L.. Seule la souche Staphylococcus aureus a montrĂ© une activitĂ© antibactĂ©rienne. Les concentrations minimales inhibitrices (CMI) des extraits flavonoĂŻdes et l’huile essentielle de Teucrium Polium L. envers la souche bactĂ©rienne sensible varient entre 0,125 et 2 ”g/ml. L’étude des concentrations minimales bactĂ©ricides (CMB) a permis de mettre en Ă©vidence l’effet bactĂ©riostatique de ces extraits, permettant de les classer comme agents antibactĂ©riens "bactĂ©ricides"

    Modular organization of the white spruce (Picea glauca) transcriptome reveals functional organization and evolutionary signatures

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    Transcript profiling has shown the molecular bases of several biological processes in plants but few studies have developed an understanding of overall transcriptome variation. We investigated transcriptome structure in white spruce (Picea glauca), aiming to delineate its modular organization and associated functional and evolutionary attributes. Microarray analyses were used to: identify and functionally characterize groups of co-expressed genes; investigate expressional and functional diversity of vascular tissue preferential genes which were conserved among Picea species, and identify expression networks underlying wood formation. We classified 22 857 genes as variable (79%; 22 coexpression groups) or invariant (21%) by profiling across several vegetative tissues. Modular organization and complex transcriptome restructuring among vascular tissue preferential genes was revealed by their assignment to coexpression groups with partially overlapping profiles and partially distinct functions. Integrated analyses of tissue-based and temporally variable profiles identified secondary xylem gene networks, showed their remodelling over a growing season and identified PgNAC-7 (no apical meristerm (NAM), Arabidopsis transcription activation factor (ATAF) and cup-shaped cotyledon (CUC) transcription factor 007 in Picea glauca) as a major hub gene specific to earlywood formation. Reference profiling identified comprehensive, statistically robust coexpressed groups, revealing that modular organization underpins the evolutionary conservation of the transcriptome structure. © 2015 The Authors

    Etude expérimentale d'un arc impulsionnel entre des contacts Ag et Ag-C

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    Impact of species and antibiotic therapy of enterococcal peritonitis on 30-day mortality in critical care - An analysis of the OUTCOMEREA database

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    Introduction: Enterococcus species are associated with an increased morbidity in intraabdominal infections (IAI). However, their impact on mortality remains uncertain. Moreover, the influence on outcome of the appropriate or inappropriate status of initial antimicrobial therapy (IAT) is subjected to debate, except in septic shock. The aim of our study was to evaluate whether an IAT that did not cover Enterococcus spp. was associated with 30-day mortality in ICU patients presenting with IAI growing with Enterococcus spp. Material and methods: Retrospective analysis of French database OutcomeRea from 1997 to 2016. We included all patients with IAI with a peritoneal sample growing with Enterococcus. Primary endpoint was 30-day mortality. Results: Of the 1017 patients with IAI, 76 (8%) patients were included. Thirty-day mortality in patients with inadequate IAT against Enterococcus was higher (7/18 (39%) vs 10/58 (17%), p = 0.05); however, the incidence of postoperative complications was similar. Presence of Enterococcus spp. other than E. faecalis alone was associated with a significantly higher mortality, even greater when IAT was inadequate. Main risk factors for having an Enterococcus other than E. faecalis alone were as follows: SAPS score on day 0, ICU-acquired IAI, and antimicrobial therapy within 3 months prior to IAI especially with third-generation cephalosporins. Univariate analysis found a higher hazard ratio of death with an Enterococcus other than E. faecalis alone that had an inadequate IAT (HR = 4.4 [1.3-15.3], p = 0.019) versus an adequate IAT (HR = 3.1 [1.0-10.0], p = 0.053). However, after adjusting for confounders (i.e., SAPS II and septic shock at IAI diagnosis, ICU-acquired peritonitis, and adequacy of IAT for other germs), the impact of the adequacy of IAT was no longer significant in multivariate analysis. Septic shock at diagnosis and ICU-acquired IAI were prognostic factors. Conclusion: An IAT which does not cover Enterococcus is associated with an increased 30-day mortality in ICU patients presenting with an IAI growing with Enterococcus, especially when it is not an E. faecalis alone. It seems reasonable to use an IAT active against Enterococcus in severe postoperative ICU-acquired IAI, especially when a third-generation cephalosporin has been used within 3 months. © 2019 The Author(s)

    Microstructure et potentiel de gonflement d’une argile du Sahara algĂ©rien

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    Durant les annĂ©es 80, une raffinerie de pĂ©trole et des bĂątiments rĂ©sidentiels divers, construits dans la rĂ©gion d’In-AmĂ©nas (au sud-est de l’AlgĂ©rie), ont subi des dommages sĂ©vĂšres dus au gonflement du sol. Quelques annĂ©es seulement aprĂšs sa rĂ©ception, la raffinerie a dĂ» ĂȘtre fermĂ©e et les constructions touchĂ©es sont tombĂ©es en ruine et ont dĂ» ĂȘtre dĂ©blayĂ©es. Des Ă©tudes rĂ©alisĂ©es sur le sol de la rĂ©gion ont montrĂ© qu’il s’agit d’une argile de type kaolinite contenant des interstratifiĂ©s : illite-vermiculite. Ces argiles prĂ©sentent habituellement un potentiel de gonflement relativement faible. Dans le but de comprendre pourquoi les argiles d’In-AmĂ©nas ont dĂ©veloppĂ© un gonflement aussi dĂ©vastateur, les rĂ©sultats d’une campagne d’essais de gonflement ont Ă©tĂ© analysĂ©s. Des investigations expĂ©rimentales complĂ©mentaires portant sur la microstructure et les propriĂ©tĂ©s de rĂ©tention d’eau du sol ont Ă©tĂ© effectuĂ©es. A la lumiĂšre de ces derniers rĂ©sultats, l’importance de la microstructure du sol sur son comportement au gonflement est mise en Ă©vidence

    Stabilisation physico-chimique des sols gonflants (sable de dune + sel)

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    Cette Ă©tude a Ă©tĂ© rĂ©alisĂ©e sur deux sols expansifs provenant de deux sites diffĂ©rents du sud de l’AlgĂ©rie, oĂč des dĂ©gĂąts ont Ă©tĂ© enregistrĂ©s (endommagement des structures, fissuration et destruction partielle des chaussĂ©es). Dans la premiĂšre Ă©tape, le gonflement des sols est estimĂ© par des mĂ©thodes indirectes basĂ©es sur les caractĂ©ristiques gĂ©otechniques. Par la suite, des mesures directes des paramĂštres de gonflement (taux et pression de gonflement) ont Ă©tĂ© effectuĂ©s. La seconde Ă©tape de cette investigation porte sur l’effet de l’ajout du sable dunaire sur le potentiel de gonflement. L’ajout de sable a conduit Ă  une diminution des limites de consistance et Ă  une rĂ©duction importante des paramĂštres de gonflement. Enfin, une technique de stabilisation combinĂ©e, par l’association de sel plus sable, a Ă©tĂ© rĂ©alisĂ©e. Les rĂ©sultats sont trĂšs encourageants et montrent que pour certaines combinaisons, le taux de rĂ©duction du potentiel de gonflement est trĂšs important (environ 95 %)

    Effect of marble powder on the properties of self-compacting sand concrete

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    Self-compacting sand concrete (SCSC) can be regarded as a flowing sand concrete, containing as principal aggregate natural sand, which can be cast without compaction or vibration. Due to the finesses of aggregates in SCSC, it requires a high amount of fine materials than other types of concretes. This paper studies the effect of marble powder content (MP) on the properties of the sand concrete (SCSC) at fresh and hardened states. The properties of the fresh prepared mixes tested are the mini-slump flow, the V-funnel flow time and viscosity. At the hardened state, the parameter which has been determined is the 28-day compressive strength. The obtained test results show that the increase of MP content in SCSC, from 150 kg/m3 to 350 kg/m3, improves the properties at fresh state by decreasing v-funnel flow time (from 5s to 1.5s) and increasing the mini-cone slump (from 28cm to 34cm). With the use of 250 kg/m3 of MP we can reach the highest initial viscosity while retaining good fluidity at high rotational speeds, compared to the MP contents of 150 kg/m3 and 350 kg/m3. In other hand, the 28-days compressive strength decreases with an increase of MP conten
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