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71.
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Discovery of Highly Selective Alkyne Semihydrogenation Catalysts Based on First‐Row Transition‐Metallated Porous Organic Polymers
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Dr. Kristine K. Tanabe Dr. Magali S. Ferrandon Dr. Nathan A. Siladke Dr. Steven J. Kraft Guanghui Zhang Dr. Jens Niklas Dr. Oleg G. Poluektov Dr. Susan J. Lopykinski Dr. Emilio E. Bunel Dr. Theodore R. Krause Dr. Jeffrey T. Miller Dr. Adam S. Hock Dr. SonBinh T. Nguyen 《Angewandte Chemie (International ed. in English)》2014,53(45):12055-12058
Five different first‐row transition metal precursors (VIII, CrIII, MnII, CoII, NiII) were successfully incorporated into a catechol porous organic polymer (POP) and characterized using ATR‐IR and XAS analysis. The resulting metallated POPs were then evaluated for catalytic alkyne hydrogenation using high‐throughput screening techniques. All POPs were unexpectedly found to be active and selective catalysts for alkyne semihydrogenation. Three of the metallated POPs (V, Cr, Mn) are the first of their kind to be active single‐site hydrogenation catalysts. These results highlight the advantages of using a POP platform to develop new catalysts which are otherwise difficult to achieve through traditional heterogeneous and homogeneous routes. 相似文献
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Magali Bardet 《Applied mathematics and computation》2011,217(17):7318-7323
The C-Algorithm introduced in [5] is designed to determine isochronous centers for Lienard-type differential systems, in the general real analytic case. However, it has a large complexity that prevents computations, even in the quartic polynomial case.The main result of this paper is an efficient algorithmic implementation of C-Algorithm, called ReCA (Reduced C-Algorithm). Moreover, an adapted version of it is proposed in the rational case. It is called RCA (Rational C-Algorithm) and is widely used in [1] and [2] to find many new examples of isochronous centers for the Liénard type equation. 相似文献
76.
Two-dimensional motion of a set of particles in a free surface flow with image processing 总被引:1,自引:0,他引:1
Tobias Böhm Philippe Frey Christophe Ducottet Christophe Ancey Magali Jodeau Jean-Luc Reboud 《Experiments in fluids》2006,41(1):1-11
A method to analyze bed load with image processing was developed. The motion of coarse spherical particles on a mobile bed entrained by a shallow turbulent flow down a steep channel was filmed with a high-speed camera. The water free surface and the particle positions were detected combining classical image processing algorithms. We developed a particle-tracking algorithm to calculate all particle trajectories and motion regimes, rolling or saltation. At constant slope, the contribution of the rolling particles to the solid discharge only slightly differed when the particle supply was increased. At a slope of 10%, it represented about 40%. In contrast, rolling became the major regime when the slope increased, at a slope of 15% it represented up to 80% of the total solid discharge.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
77.
Elise Champion Isabelle André Laurence A. Mulard Pierre Monsan Magali Remaud-Siméon Sandrine Morel 《Journal of carbohydrate chemistry》2013,32(3):142-160
Transglucosylation reactions using sucrose as glucosyl donor and either N-acetyl-D-glucosamine, L-rhamnose, or methyl α -L-rhamnopyranoside as acceptors were carried out with recombinant glucansucrases from families 70 and 13 of glycoside-hydrolases. Depending on the enzyme specificity, various carbohydrate structures were synthesized and characterized including α -D-glucopyranosyl-(1 → 6)-N-acetyl-D-glucosamine, α -D-glucopyranosyl-(1 → 4)-N-acetyl-D-glucosamine, α -D-glucopyranosyl-(1 → 1)-β -L-rhamnopyranoside, α -D-glucopyranosyl-(1 → 4)-α -D-glucopyranosyl-(1 → 1)-β -L-rhamnopyranoside, methyl α -D-glucopyranosyl-(1 → 4)-α -L-rhamnopyranoside, and methyl α -D-glucopyranosyl-(1 → 3)-α -L-rhamnopyranoside. Disaccharides were obtained with yields going up to 64%. The structural diversity generated as well as the obtained yields appear to be related to enzyme active site architecture, which can be modulated and improved by enzyme engineering. Several of the obtained disaccharides enter in the composition of surface polysaccharides of pathogenic bacteria, among which is Shigella flexneri. Our results outline the potential of glucansucrases in the chemo-enzymatic synthesis of complex carbohydrates of biological interest whose chemical synthesis may be seen as a limitation. 相似文献
78.
Magali Defosseux 《Tetrahedron》2005,61(32):7632-7653
The oxymercuration-reductive demercuration of several cyclopropanealkanol or their derivatives bearing adjacent stereocenters has been investigated in order to synthesize polypropionate subunits. The crucial importance of the ester protecting group for the remote oxygenated moieties on the mechanism and the stereochemical outcome of these reactions has been rationalized. 相似文献
79.
Design of Potent Mannose 6‐Phosphate Analogues for the Functionalization of Lysosomal Enzymes To Improve the Treatment of Pompe Disease
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Afitz Da Silva Dr. Coralie Bernon Dr. Pierre Cérutti Dr. Frédéric Salgues Marc Perez Dr. Marie Maynadier Dr. Magali Gary‐Bobo Dr. Catherine Caillaud Dr. Martine Cérutti Dr. Marcel Garcia Prof. Alain Morère 《Angewandte Chemie (International ed. in English)》2016,55(47):14774-14777
Improving therapeutics delivery in enzyme replacement therapy (ERT) for lysosomal storage disorders is a challenge. Herein, we present the synthesis of novel analogues of mannose 6‐phosphate (M6P), known as AMFAs and functionalized at the anomeric position for enzyme grafting. AMFAs are non‐phosphate serum‐resistant derivatives that efficiently bind the cation‐independent mannose 6‐phosphate receptor (CI‐M6PR), which is the main pathway to address enzymes to lysosomes. One of the AMFAs was used to improve the treatment of the lysosomal myopathy Pompe disease, in which acid α‐glucosidase (GAA) is defective. AMFA grafting on a M6P‐free recombinant GAA led to a higher uptake of the GAA in adult Pompe fibroblasts in culture as compared to Myozyme, the M6P recombinant GAA. Moreover, the treatment of Pompe adult mice with the AMFA‐grafted recombinant enzyme led to a remarkable improvement, even at low doses, in muscle functionality and regeneration, whereas Myozyme had limited efficacy. 相似文献
80.
Bonne M Bion N Pailloux F Valange S Royer S Tatibouët JM Duprez D 《Chemical communications (Cambridge, England)》2008,(37):4504-4506
This work reports the synthesis of homogeneously dispersed mixed-oxide nanoparticles (<5 nm) exhibiting improved lattice oxygen mobility (ca. two times higher than on bulk samples), using a novel synthesis procedure of nanocasting in mesoporous silica host support. 相似文献