Dendrimer catalysis,impact of dendrimers on catalytic centers at their periphery

Les dendrimères sont des macromolécules hyperbranchées très bien définies. Ces molécules possèdent des applications dans de nombreux domaines dont la catalyse. L'objectif de ce travail est l'étude de l'impact du dendrimère sur les catalyseurs greffés à saDendrimers are highly branched macromolecules very well defined. These molecules possess applications in several scientific fields, including catalysis. The goal of this work is to study the impact of dendrimer onto catalysts immobilized in its peripher

Utilisation des dendrimères en catalyse (Etude de l'impact du dendrimère sur les catalyseurs greffés à sa surface)

Les dendrimères sont des macromolécules hyperbranchées très bien définies. Ces molécules possèdent des applications dans de nombreux domaines dont la catalyse. L'objectif de ce travail est l'étude de l'impact du dendrimère sur les catalyseurs greffés à sa surface et principalement celui sur l'énantiosélectivité d'une réaction.Dans ce but, nous avons fonctionnalisé la périphérie des dendrimères poly(amido)amines et poly(propylène)imines avec le ligand Pyrphos qui est une diphosphine chirale.Les complexes de rhodium(I) de ces dendrimères ont fait l'objet d'une étude en catalyse d'hydrogénation asymétrique des alcènes. La nature et la taille du dendrimère ne semblent pas avoir d'influence sur l'énantiosélectivité de cette réaction. Une méthode d'immobilisation des complexes dendritiques de rhodium(I) sur des billes de silice par formation de structures multicouches par interactions électrostatiques a été développée et des monocouches de ces dendrimères ont été testées en catalyse d'hydrogénation.Les complexes dendritiques de palladium(II) ont, quant à eux, été étudiés en catalyse de substitution allylique. Une forte augmentation de l'énantiosélectivité de la réaction avec l'accroissement de la taille du dendrimère ainsi qu'une influence de la nature du dendrimère ont été observées. Au cours de l'étude de l'origine de cet effet dendritique, l'implication d'un complexe de palladium portant deux diphosphines a été mis en évidence.Dendrimers are highly branched macromolecules very well defined. These molecules possess applications in several scientific fields, including catalysis. The goal of this work is to study the impact of dendrimer onto catalysts immobilized in its periphery and more precisely the impact on the enantioselectivity of a reaction.With this aim in view, we functionalised the periphery of poly(amido)amine and poly(propylene)imine dendrimers with the Pyrphos ligand, which is a chiral diphosphine.The rhodium(I) complexes of these dendrimers were tested in asymmetric hydrogenation catalysis of alkenes. The enantioselectivity of this reaction was found to be independant of the size and type of the dendrimer. A methode of immobilisation of the dendritic rhodium(I) complexes on silica by electrostatic multilayers structures was developed and, immobilized monolayers of dendrimers were tested in asymmetric hydrogenation.The dendritic palladium(II) complexes were used in allylic substitution catalysis. A strong increase of the enantioselectivity as a function of the dendrimer size and a impact of the type of the dendrimer were observed. During the elucidation of this positive dendritic effect on the enantioselectivity, the implication of a bisdiphosphine palladium complex was underlined.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

MORTALITE CHEZ DES PATIENTS FREQUENTANT UN SECTEUR PSYCHIATRIQUE

This study followed during 10 years 322 belgian patients aged between 20 and 39 years living in the district of Anderlecht and who had presented themselves for the first time to the psychosocial sector of this district between 1970 and 1973. Fifteen deaths were observed, 10 of which were among the under 30's. The S.M.R. observed (5.27) is similar to the results obtained in other international studies. The survival curves (Kaplan-Meier method) confirm the more considerable excess of mortality during the first years of the follow-up. The deceased sample was matched to a control sample of patients frequenting the centre and compared by the Mac Nemar test. There was very little difference between the two samples. The deceased had however rarely moved house during their follow-up and had accumulated a series of risk factors from the beginning.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Analyse des données santé mentale de l'enquête nationale de santé, Belgique 1997

info:eu-repo/semantics/publishe

Premature death among outpatients at a community mental health center

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Epidemiological survey of the "natural" mortality in psychiatry

The authors reviewed articles published from 1838 dealing with excess of > mortality in psychiatric > and > patients. The high natural mortality rate has always existed and is still observed today despite the quality of somatic care. The excess is observed in every country, echnic group, sex, age or site of treatment but does not seem to be associated with specific organic pathology. The risk of > mortality (suicide and accidents excluded) remains 2 to 5 times greater than in normals. Hypotheses concering the phenomenon are reviewed or suggested.SCOPUS: re.jinfo:eu-repo/semantics/publishe