Search results for "chemin"
showing 8 items of 58 documents
Etude numérique du comportement thermique d’un séchoir solaire utilisant un lit thermique pour le stockage d’énergie
2018
This thesis presents a numerical study of an indirect natural convection solar dryer for drying agricultural products (Figs). The first part analyzes a solar dryer containing a drying chamber coupled to a reversed absorber and a solar chimney. Simulations were made to determine the dynamic and thermal fields under the influence of the variation of the solar chimney configuration and the size of the inlet opening. The governing equations based on the standard k-ε turbulence model are solved by the finite volume method using the ANSYS-Fluent commercial code. The second part analyzes the effect of adding a thermal storage in the form of a gravel bed in the drying chamber. The bed is modeled as…
Engineering faster transglycosidases and their acceptor specificity
2019
Transglycosidases are enzymes that have the potential to catalyze the synthesis of a wide range of high-value compounds starting from biomass-derived feedstocks. Improving their activity and broadening the substrate range are important goals to enable the widespread application of this family of biocatalysts. In this work, we engineered 20 mutants of the rice transglycosidase Os9BGlu31 and evaluated their catalysis in 462 reactions over 18 different substrates. This allowed us to identify mutants that expanded their substrate range and showed high activity, including W243L and W243N. We also developed double mutants that show very high activity on certain substrates and exceptional specific…
Straightforward synthesis of bioconjugatable azo dyes. Part 2: Black Hole Quencher-2 (BHQ-2) and BlackBerry Quencher 650 (BBQ-650) scaffolds
2014
Abstract A further extension of the efficient synthetic methodology described in Part 1, to the aromatic bis-diazo scaffold of Black Hole Quencher-2 dye is presented. Bioconjugatable derivatives bearing either azido, terminal alkyne, or maleimide reactive group were easily obtained as well as the free-phenol form of BlackBerry® Quencher 650 (BBQ-650®) initially developed by Berry & Associates, Inc. Company. The efficient conjugation ability of azido- and maleimide-quenchers was demonstrated through the facile preparation of the first water-soluble and formylated BHQ-2 dyes and a FRET-based probe suitable for the in vitro/in cellulo detection of a cancer-associated protease namely urokinase-…
Straightforward synthesis of bioconjugatable azo dyes. Part 1: Black Hole Quencher-1 (BHQ-1) scaffold
2014
Abstract Azo dyes are currently used to quench the fluorescence of energy donors in bioassays through Forster resonance energy transfer (FRET) phenomenon. Common examples of such dark quenchers are DABCYL and the three members of Black Hole Quencher® (BHQ) family. Yet, only carboxylic acid and phosphoramidite derivatives of such azo dyes are presently commercially available. This Letter presents a straightforward synthesis method to novel bioconjugatable quenchers derived from BHQ-1 scaffold and equipped with a reactive group being either azido, terminal alkyne, or maleimide. The potential utility of the ‘clickable’ azido and thiol-reactive derivatives was notably demonstrated through the p…
New insights into the water-solubilization of thiol-sensitive fluorogenic probes based on long-wavelength 7-hydroxycoumarin scaffolds
2014
Abstract The synthesis and photophysical properties of novel water-soluble phenol-based fluorophores derived from 3-benzothiazolyl-7-hydroxycoumarin and emitting in the range 485–631 nm are described. Further conversion into thiol-sensitive fluorogenic probes through the chemical modification of their hydroxyl group was next investigated. Depending on the type of thiol-reactive quenching moiety used (2,4-dinitrobenzenesulfonyl ester, 2,4-dinitrophenyl ether or benzoquinone-type Michael acceptors) and the water-solubilizing group(s) pre-introduced into the coumarin core, dramatic differences in the thiol-induced fluorescence activation of these pro-fluorophores under physiological conditions…
Les vulnérabilités étudiantes : quels effets sur les parcours ?
2023
Les vulnérabilités étudiantes sont cumulatives et multidimensionnelles. Elles ont un effet négatif sur les parcours d’études et la réussite au diplôme des étudiants concernés.
Dépenses d’enseignement dans les collèges privés et publics et indice de positionnement social : une analyse spatiale et longitudinale
2023
Introduction En France, depuis 1963, date d’instauration de la carte scolaire, l’affectation des élèves dans un collège est fonction de son lieu de résidence. Ainsi, chaque élève est affecté à un collège public à proximité de son domicile. Par essence, cette méthode d’affectation reproduit au sein des collèges la ségrégation résidentielle. La possibilité d’obtenir des dérogations à cette affectation administrative, l’assouplissement de la carte scolaire de 2007, et la liberté de scolariser so...
Les aspirations professionnelles des élèves sous le prisme des valeurs et compétences « vertes »
2022
Introduction Les enjeux environnementaux sont une des lignes de fracture importante entre les valeurs des générations, les jeunes devant faire face à l’héritage des générations précédentes (Peugny et Van de Velde, 2013). L’école semble y jouer un rôle de plus en plus majeur en multipliant les terrains d’apprentissage de ces problématiques alliant connaissances théoriques et éco-gestes (Glomeron et al., 2017). Ils se déclinent néanmoins de manière très variable selon les pays et leurs politiqu...