23 research outputs found
Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora
Essai d’une complémentation alimentaire au flushing et au steaming de brebis ouled djellal par la caroube
This study aims to substitute a concentrate containing whole carob food to the concentrate containing barley. It concerned fifty ewes, randomly divided into two groups : a control group that received supplementation based on a ration R1 containing wheat bran (30 %) and barley grains (70 %) in the flushing and steaming, while experimental group received at the same time a ration R2 containing wheat bran (30 %) and whole carob (70 %). The impact of this complementation was evaluated by body condition score at mating, before lambing, reproductive performance and lamb growth. The body condition scores in breeding were significantly identical between the two groups (3.33 vs. 3.48) and at lambing (2.87 vs. 2.94). Similarly, growth rates of lambs were not significantly different (p>0.05). Thus, the energy supplements (barley vs. carob) can be substituted.La présente étude a pour but la substitution d’un concentré à base de caroube entière à un concentré à base d’orge. Elle a concerné cinquante brebis, réparties aléatoirement en deux lots: un lot témoin ayant reçu une complémentation à base d’une ration R1 constituée de 30 % son de blé et de 70 % d’orge en grains au flushing puis au steaming, et un lot expérimental qui a reçu un concentré R2 à base de 30 % de son de blé et de 70 % de caroube entière. L’impact de cette complémentation a été évalué par les notes d’état corporel (NEC) à la lutte et à la mise bas, les performances de reproduction ainsi que la croissance des agneaux. Les NEC ont été significativement identiques entre les deux lots à la lutte (3,33 vs. 3,48) et à la mise bas (2,87 vs. 2,94). De même, les vitesses de croissance ont été significativement similaires (p>0,05). Ainsi, les compléments énergétiques (orge vs. caroube) peuvent se substituer
Evidence for equilibrium crystallization of amphiboles and clinopyroxenes in mantle modally metasomatized peridotite xenoliths from french Massif Central
International audienc
Evidence for a single metasomatic event in the lithosphere beneath the french Massif Central: mineralogical, geochemical and isotopic constraints from mantle hydrous xenoliths from the Deves province
International audienc
Mechanisms of melt migration and mantle metasomatism in the lithosphere beneath the French Massif Central
International audienc
Crystal Structure of the Low-Temperature Form and Evolution during the Phase Transition of the Electronic Properties of a Mixed-Valence Vanadium Oxide Inserting Quinuclidinium Cations
Effects of synthetic conditions on the structure and morphology of open-ended vanadium oxide nanotubes and study of their growth mechanism
Classification and Identification of Enterococci: a Comparative Phenotypic, Genotypic, and Vibrational Spectroscopic Study
Rapid and accurate identification of enterococci at the species level is an essential task in clinical microbiology since these organisms have emerged as one of the leading causes of nosocomial infections worldwide. Vibrational spectroscopic techniques (infrared [IR] and Raman) could provide potential alternatives to conventional typing methods, because they are fast, easy to perform, and economical. We present a comparative study using phenotypic, genotypic, and vibrational spectroscopic techniques for typing a collection of 18 Enterococcus strains comprising six different species. Classification of the bacteria by Fourier transform (FT)-IR spectroscopy in combination with hierarchical cluster analysis revealed discrepancies for certain strains when compared with results obtained from automated phenotypic systems, such as API and MicroScan. Further diagnostic evaluation using genotypic methods—i.e., PCR of the species-specific ligase and glycopeptide resistance genes, which is limited to the identification of only four Enterococcus species and 16S RNA sequencing, the “gold standard” for identification of enterococci—confirmed the results obtained by the FT-IR classification. These results were later reproduced by three different laboratories, using confocal Raman microspectroscopy, FT-IR attenuated total reflectance spectroscopy, and FT-IR microspectroscopy, demonstrating the discriminative capacity and the reproducibility of the technique. It is concluded that vibrational spectroscopic techniques have great potential as routine methods in clinical microbiology
Heterofucans from Dictyota menstrualis have anticoagulant activity
Fucan is a term used to denote a family of sulfated L-fucose-rich polysaccharides which are present in the extracellular matrix of brown seaweed and in the egg jelly coat of sea urchins. Plant fucans have several biological activities, including anticoagulant and antithrombotic, related to the structural and chemical composition of polysaccharides. We have extracted sulfated polysaccharides from the brown seaweed Dictyota menstrualis by proteolytic digestion, followed by separation into 5 fractions by sequential acetone precipitation. Gel electrophoresis using 0.05 M 1,3-diaminopropane-acetate buffer, pH 9.0, stained with 0.1% toluidine blue, showed the presence of sulfated polysaccharides in all fractions. The chemical analyses demonstrated that all fractions are composed mainly of fucose, xylose, galactose, uronic acid, and sulfate. The anticoagulant activity of these heterofucans was determined by activated partial thromboplastin time (APTT) using citrate normal human plasma. Only the fucans F1.0v and F1.5v showed anticoagulant activity. To prolong the coagulation time to double the baseline value in the APTT, the required concentration of fucan F1.0v (20 µg/ml) was only 4.88-fold higher than that of the low molecular weight heparin Clexane® (4.1 µg/ml), whereas 80 µg/ml fucan 1.5 was needed to obtain the same effect. For both fucans this effect was abolished by desulfation. These polymers are composed of fucose, xylose, uronic acid, galactose, and sulfate at molar ratios of 1.0:0.8:0.7:0.8:0.4 and 1.0:0.3:0.4:1.5:1.3, respectively. This is the fist report indicating the presence of a heterofucan with higher anticoagulant activity from brown seaweed