20 research outputs found

    CRANIOPLASTIE ASSISTEE PAR ORDINATEUR

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    LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Différentes stratégies pour l'inclusion de nanoparticules de Rh(O) au sein de supports mésoporeux structurés utilisant des précurseurs ioniques ou des colloïdes (application à l'hydrogénation de dérivés aromatiques dans des conditions douces)

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    Ce mémoire présente différentes approches pour inclure des particules de Rh(0) au sein de supports MCM41 et SBA15. Les précurseurs sont le chlorure de rhodium(III) ainsi qu une dispersion de colloïdes de rhodium(0) stabilisée par le chlorure de N,N-diméthyl-N-cétyl-N-(2-hydroxyéthylammonium) (HEACl).Des matériaux Rh0-MCM41 bien structurés ont été obtenus par incorporation de Rh(III) dans le gel de synthèse ou par imprégnation du solide natif suivies d un traitement par H2. Dans le cas des silices SBA15, d autres voies ont été mises en œuvre pour favoriser la localisation et la dispersion des particules au sein des canaux. Ainsi, l ancrage de cations rhodium(III) par coordination avec des ligands N-propyl-4,5-dihydroimidazole pré-positionnés a permis d aboutir à des nanoparticules bien dispersées. Les colloïdes Rh0/HEACl ont également été préparés par nucléation hétérogène sur silice ou silice alumine de type SBA15. Dans ce cas, la taille des particules n est plus contrôlée par le diamètre des pores. Le solide est bien structuré et d importantes quantités de métal sont incorporées comparativement aux protocoles de synthèse directe ou d imprégnation impliquant des suspensions de colloïdes préformés. Les solides à base de rhodium(0) ont été caractérisés et testés comme catalyseurs d hydrogénation de composés aromatiques dans des conditions douces (température ambiante, 0,1 MPa H2). Les matériaux les plus actifs sont ceux obtenus par nucléation hétérogène. La plupart des solides décrits sont plus performants que les catalyseurs commerciaux. Les sélectivités cis/trans dégagées lors de l hydrogénation de composés aromatiques disubstitués sont plus élevées en cas d imprégnation.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

    A polo ball in the right atrium, importance of echocardiographic characteristics of intracardiac myxomas: a case report

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    Abstract Background Myxomas are the most prevalent type of heart tumors, mainly occurring in the left atrium, with approximately 20% of cases found in the right atrium. Timely diagnosis and appropriate management of myxomas are crucial for favorable outcomes and to minimize complications. Case presentation A 77-year-old Asian male with no significant medical history presented with intermittent trepopnea and palpitations. Physical examination revealed regular heart sounds and no other relevant findings. A transthoracic echocardiogram showed a large, round-shaped, smooth-edged mass with diameter of 86 mm, occupying most of the right atrium. Mild tricuspid flow obstruction and mild left ventricular systolic dysfunction were also observed. Cardiac tomography confirmed the size, smooth edges, and showed microcalcifications of the mass, with no invasion of surrounding tissues. Surgical intervention successfully removed the spheroid mass, leading to the alleviation of symptoms. Histopathology confirmed the myxoma nature of the mass. A comprehensive discussion based on relevant medical literature is provided, with emphasis on echocardiographic characteristics of the mass with relation to potential embolic disease. Conclusion This case shows an atypical presentation of an exceptionally large myxoma in the right atrium, resembling the size of a polo ball, in a patient presenting with supraventricular arrhythmia and trepopnea. Early diagnosis and appropriate management played a vital role in achieving a successful outcome for the patient

    The effect of pre-dive ingestion of dark chocolate on endothelial function after a scuba dive.

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    The aim of the study was to observe the effects of dark chocolate on endothelial function after scuba diving.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Reduced forms of Rh(III) containing MCM-41 silicas as hydrogenation catalysts for arene derivatives

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    International audienceRhodium containing mesoporous siliceous materials with MCM-41 pore architecture have been prepared via a template directed hydrolysispolycondensation of tetraethoxysilane and rhodium(III) chloride in aqueous ammonia. The effect of aging and hydrothermal conditions on rhodium incorporation and on the porous structure of the resulting solids has been examined using elemental analysis, powder X-ray diffraction (XRD), N2 sorption measurements and transmission electron microscopy (TEM). Optimized synthetic conditions afforded MCM-41 materials with Si/Rh 1400 and 120. Subsequent reduction of rhodium oxides species by hydrogen emphasized that the growth of Rh0 particles (2–3 nm) is controlled by the porosity of the support. The conditions and efficiency of this step were evaluated through H2-TPR (temperature programmed reduction) and IR monitored CO adsorption studies. The resulting materials showed a good catalytic activity and stability in the hydrogenation of arene derivatives under mild pressure and temperature. Cis/trans selectivity of dimethylcyclohexanes was discussed in the light of dispersion measurements

    A surfactant-assisted preparation of well dispersed rhodium nanoparticles within the mesopores of AlSBA-15: characterization and use in catalysis

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    International audienceWell dispersed and efficient Rh(0) hydrogenation catalysts were obtained by the redn. of Rh(iii)-exchanged mesoporous aluminosilicates by sodium borohydride in the presence of N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl) ammonium chloride

    Dark chocolate reduces endothelial dysfunction after successive breath-hold dives in cool water.

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    The aim of this study is to observe the effects of dark chocolate on endothelial function after a series of successive apnea dives in non-thermoneutral water.JOURNAL ARTICLEinfo:eu-repo/semantics/publishe
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