La rétention aiguë d'urine est la complication la plus grave de l'hyperplasie bénigne de la prostate. Elle est aujourd'hui traitée en urgence par cathétérisation, ce qui expose le patient à un important risque infectieux. Dans le cadre de cette thèse, un stent urétral innovant a été développé afin de remplacer la cathétérisation. Ce stent utilise des échantillons filiformes d'alliage à mémoire de forme Nickel-Titane, lui conférant deux mémoires de forme distinctes au chauffage, et permettant ainsi une pose et une ablation simplifiées.Afin de convenablement dimensionner les éléments constitutifs de ce stent, un dispositif permettant la réalisation d'essais de flexion pure à haute déformation sur des échantillons de géométrie filiforme a été conçu. Ce dispositif a permis la caractérisation de fils et tubes de NiTi en flexion pure, ainsi que l'étude du phénomène de localisation qui est survenue lors de ces essais.Une méthode numérique permettant l'identification des lois de comportement matériau à partir d'essais expérimentaux à champ de contrainte non uniforme a été développée. Cette méthode a notamment permis d'identifier le comportement en compression uni-axiale de fils et tubes de NiTi, à partir de résultats expérimentaux obtenus en flexion pure et en traction uni-axiale. / Acute urinary retention is the major complication of benign prostatic hyperplasia. Today, the first line treatment consists in emergency catheterization, which often leads to urinary infection. This thesis aimed at developing an innovative nitinol based stent as a alternative treatment for acute urinary retention. Using a combination of NiTi wires and tubes, this stent is given two distinct shape memories during heating.The stent components are mostly loaded under pure bending during the stent activation. A pure bending apparatus allowing large deformations on slender specimens was thus designed. This device gave access to the NiTi wires and tubes behaviour under pure bending, and also provided information about localization phenomena during pure bending experiment.A numerical method able to identify the shear-stress shear-strain function from experimental pure torsion tests, and the stress strain function under compressive load from experimental uni-axial tensile and pure bending tests was also developed. This method was applied using afore-obtained numerical results to identify the NiTi wires and tubes behaviour under uni-axial compressive load.

As próteses faciais e intraorais tem um importante papel na devolução da estética e de algumas funções para os pacientes. Por meio da restauração da imagem corporal é possível reintegrá-lo a sociedade, resgatando assim a identidade do indivíduo. A boa condição dessas próteses é primordial para que estas possam exercer suas funções adequadamente e manter o local, onde estão inseridas, livre de infecções e inflamações. Portanto, a não formação de colônias e biofilmes bacterianos em materiais eleitos para confecção dessas próteses, trarão benefícios aos pacientes reabilitados. Visando isso, a presente dissertação verificou a capacidade de inclusão e a eficiência bactericida do biocida policloreto de dialildimetilamônio (PDADMAC) em resina acrílica autopolimerizável (RAAQ) e termopolimerizável (RAAT), e silicone de uso médico. Os resultados mostraram que o biocida PDADMAC quando dissolvido no tetrahidrofurano apresentou boa incorporação tanto nas resinas acrílicas, quimicamente ativas e termo ativas, quanto no silicone de uso médico e que apenas os corpos de prova que receberam 2 mililitros do PDADMAC em massa polimérica tiveram uma resposta bactericida eficaz. / The facial and intraoral prosthesis has an important role in the aesthetics and return of some functions to patients. Through restoration of the body image can reistante to can society , thus recovering the individual\'s identity . The good condition of these prostheses is essential so they can perform their function properly and maintain the the area where the prostheses are inserted free of infection and inflammation. Therefore, no formation of bacteria colonies and biofilms in the chosen materials for making these prostheses , will bring benefits to patients rehabilitated. The present work evaluated the capability of inclusion and the bactericidal efficiency of the biocide poly(diallyldimethylammonium chloride) ( pDADMAC ) of acrylic resin autopolymmerized ( RAAQ ) and thermal polymerized ( RAAT ) , and silicone medical use. The results showed that the biocide pDADMAC when dissolved in tetrahydrofuran presented a good incorporation in both acrylic resins and in the medical grade silicone and that only the samples that received 2 ml of pDADMAC in polymer had an effective bactericidal response.

L’électronique embarquée, notamment les modules de puissance, permet la gestion de l’énergie électrique et donc le développement de véhicules « décarbonés ». Toutefois, en vue d’être positionnés près du moteur thermique, ces composants électroniques devront résister à des environnements très divers et parfois à de sévères contraintes (humidité, agression chimique (huiles), vibrations…). Or, les matériaux d’encapsulation qui les protègent ne sont pas, aujourd’hui, assez performants pour répondre à ces nouvelles contraintes. Ainsi, le but de ces travaux de thèse est donc de développer de nouveaux polymères d’encapsulation. Pour cela, deux types de copolymères Silicone/Polyuréthane (Si/PU) réticulés ont été synthétisés, sans solvant, et avec des temps de polymérisation courts.Une première série de matériaux Si/PU contenant entre 55 et 76%m de motif silicone, a été synthétisée par polyaddition alcool-isocyanate à partir de précurseurs silicone, synthétisés ou commerciaux, et d’un pluriisocyanate, en présence d’un catalyseur. Une seconde série de copolymères Silicone/Polyhydroxyuréthane (Si/PHU) contenant 26 et 61%m de motif silicone a été obtenue sans isocyanate et sans catalyseur, à partir de poly(diméthylsiloxane) biscyclocarbonate et d’une triamine.Les propriétés mécaniques, thermiques et le caractère hydrophobe de tous ces matériaux ont été évalués. Dans le but d’améliorer les propriétés thermiques et de diminuer le coût de la résine d’encapsulation, des charges inorganiques ont été incorporées à certains polymères Si/PU.Les matériaux les plus intéressants ont été testés comme encapsulant dans des modules de puissance et les premières mesures électriques au cours de cyclages thermiques sont très prometteuses. / Embedded electronics, particularly power modules, allows management of electric energy and therefore development of “carbon-free” vehicle. However, these electronic components, will shortly be located near heat engine automotive, and they must withstand various environments and sometimes, hard stresses (humidity, chemical aggression (oil), vibrations…). But actual encapsulation materials are not today efficient enough to match with these future imposed stresses. Thus, the aim of this work is to develop new encapsulation polymers. For this, two types of crosslinked Silicone/Polyurethane (Si/PU) copolymers were “solvent-free” synthesized and with short polymerization times.A first series of materials Si/PU containing between 55 and 76%wt silicone units were synthesized by alcool-iscyanate polyaddition from silicone precursor, synthesized or commercial, and a pluri-isocyanate, in the presence of catalyst. A second series of copolymers, Silicone/Polyhydroxyurethane (Si/PHU) containing 26 and 61%wt silicone units, was obtained without isocyanate or catalyst from poly(dimethylsiloxane) biscyclocarbonate and a triamine.Mechanical and thermal properties as well as hydrophobic character of all materials were evaluated. In order to improve thermal properties and decrease the cost of encapsulation resin, inorganic fillers were blended in some of Si/PU polymers.The most interesting materials were tested as encapsulant in power modules, and the first electrical measurements during thermal cyclings were very promising

No description available.

Although the use of silicon-based reagents has undergone rapid development during the last twenty years, the application of organosilicon chemistry to asymmetric synthesis has been somewhat slower to develop. The many problems associated with the use of 'Si-centred' chiral organosilicon compounds has led to the application of 'C-centred' chiral organosilicon compounds. This work has been aimed at the synthesis and application of cyclic silicon species. Routes towards the synthesis of medium-sized rings have been investigated as a potential application of enantiomerically pure silacycles. This work has led to the discovery of an unusual tandem cycloaddition-bond fragmentation reaction of 3-(dienylacyloxy)cycloalk-2- en-l-ones, which affords a-tetralone as the principal product. Most work has been directed at the synthesis of asymmetric silacycles. Two routes have been explored. Firstly, the double asymmetric hydrosilylation of dienes, catalysts based on many transition metals were used but little evidence of hydrosilylation was observed. The second route is that of the double asymmetric hydroboration of divinylsilanes. Asymmetric stoichiometric hydroboration led to products of moderate to high enantiomeric excess, whilst rhodium-catalysed hydroboration led to high yields of the achiral syn isomer. The diastereoselectivity has been found to vary according to the length of the tether between two phosphine ligands, with maximum diastereoselectivity being observed for butanodiphosphines. NMR studies have investigated the possibility that this is related to the stability of a divinylsilane-diphosphine rhodium complex. Finally, the formation of a variety of silacycles has been attempted. Boron- redistribution of the product of hydroboration with (-)-diisopinocampheylborane has been shown to occur with retention of stereochemistry and subsequent carbonylation led to the formation of asymmetric silacyclohexanones. Oxidation of the hydroboration product led to the formation of a silyldiol species. Reactions of this silyldiol have provided the basis for encouraging preliminary attempts at the formation of other heterosilacycles.

Thesis (doctoral)--Karolinska Institutet, Stockholm, 1994. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (doctoral)--Karolinska Institutet, Stockholm, 1994. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Universiẗat, Diss., 2000--Mainz. / Zeichendarstellung im Hauptsachtitel teilweise nicht vorlagegemäß wiedergegeben. Auch als gedr. Diss.

Thesis (Ph.D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 113-119). Also available on the Internet.

Thesis (Ph.D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 113-119). Also available on the Internet.