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Cette thèse, réalisée dans le cadre du projet PCP (Piles à Combustible par Procédés Plasma) est le fruit d’une collaboration de plusieurs années : Dreux Agglomération, les laboratoires GREMI et IEM, et l’industriel MHS Equipment. L’objectif de ce travail étant la fabrication par procédé plasma, d’un coeur de pile à combustible, dans un réacteur prototype préindustriel. Pour ce faire, deux études de faisabilités ont été menées en parallèle. La première étude, à l’IEM, porte sur la synthèse, par polymérisation plasma dans un réacteur pilote, de membranes polymères conductrices de protons. Deux précurseurs ont été utilisés : le styrène et l’acide trifluorométhanesulfonique. Les membranes polymères plasma se présentent sous la forme de dépôts denses, homogènes, et très adhérents à leur support en tissu carboné. Les membranes plasma sont intrinsèquement bien moins conductrices que la membrane commerciale Nafion®, néanmoins, leur niveau de conduction reste satisfaisant du fait de leur faible épaisseur. Les membranes plasmas profitent de leur densité et de leur fort taux de réticulation pour disposer une imperméabilité au méthanol beaucoup plus importante que celle du Nafion®. La stabilité thermique des membranes plasma, également évaluée, leur permet de supporter les températures de fonctionnement des piles. La seconde étude concerne l’élaboration des électrodes par pulvérisation magnétron dans le réacteur pilote au GREMI. L’utilisation d’une configuration de dépôt à une cible de platine ou de la combinaison d’une cible de platine et d’une cible de carbone, a permis de réduire la quantité de platine déposé sur le support carboné et conduit à l’optimisation de la dispersion du platine pour une meilleure efficacité catalytique. En outre, dans un contexte industriel, l’intégration de l’assemblage membrane électrode a été transférée sur un prototype linéaire combinant en une seule fois la polymérisation plasma et la pulvérisation magnétron. Des coeurs de pile ont été fabriqués et testés en banc de pile. / This work is part of PCP (Piles à Combustible par Procédés Plasma) project with the involvement of many partners: Dreux Agglomeration Community, GREMI and IEM laboratories, and the private industrial MHS Equipment. The aim of this work is the development of pre-industrial reactor prototype in order to manufacture by plasma processes all active layers of fuel cells cores i.e. the electrodes and the membrane. Two studies were conducted at the same time. The first from IEM have focused on the preparation by plasma polymerization, in a pilot reactor, of proton conducting polymer membranes. Two precursors were used: styrene and trifluoromethanesulfonic acid. The plasma membranes obtained are dense, uniform, and very adherent on carbon cloth support. The intrinsic ionic conductivity of plasma polymerized membranes is lower than the one of Nafion® membranes but their conduction ability is observed to be competitive due to their low thickness. Due to their highly cross-linked structure and density, plasma-polymerized membranes show methanol permeability much lower than Nafion® membranes ones. The thermal stability measurements have shown that plasma membranes easily support the operating temperature of fuel cells. The second study from GREMI concerns the development of catalyst or integral catalytic electrodes by magnetron sputtering in the pilot reactor. The use of a single platinum target or the combination of both platinum and carbon targets allowed to reduce the platinum content and to control the platinum concentration profile in the electrode support leading to the optimization of the platinum dispersion for a high increase of catalyst efficiency. Furthermore, in an industrial context, MEA’s integration was transferred using a linear industrial prototype which combines plasma polymerization for the membrane deposition and plasma sputtering for Pt deposition in a single device. Compact plasma MEA are produced and characterized in mono-cells.

Macrophage generation of reactive nitrogen intermediates (RNI) represents a major effector mechanism in anti‐microbial immunity and non‐septic inflammatory reactions. The induction of macrophage RNI production has been demonstrated to require at least two signals which in microbial infections can be provided by interferon (IFN)‐γ and lipopolysaccharide (LPS). The current study demonstrates that, in the absence of LPS, T lymphocytes can provide cognate signal(s) which synergize with IFN‐γ in stimulating macrophage RNI production, as evidenced by the ability of plasma membranes from T cell clones to activate IFN‐γ‐primed macrophages. Although viable resting T cells can activate IFN‐γ‐primed macrophages by an interaction that is antigen specific, plasma membranes from resting T cells do not activate macrophages. Plasma membranes from T cells activated by immobilized anti‐CD3 were able to effectively induce RNI production in IFN‐γ‐primed macrophages. However, in contrast to the antigen‐specific interaction of macrophages with viable resting T cells, the activation of IFN‐γ‐primed macrophages by membranes from activated T cells does not display antigen specificity. Plasma membranes from activated T helper TH2 and from activated TH1 cells were equally effective in activating IFN‐γ‐primed macrophages, suggesting that the dominance of TH1 over TH2 cells in cell‐mediated responses involving macrophage effectors is not a reflection of differences in their ability to interact with macrophages but rather is a reflection of their different pattern of cytokine production. These results suggest that the T cell‐macrophage interaction involves reciprocal activation of both cells ‐ an antigen‐specific activation of the T cells which results in the acquisition of T cell membrane components involved in antigen‐nonspecific stimulation of the macrophages.

The kidney is one of the most affected organs of body from diabetes. Diabetic kidney disease is a complication of diabetes seen in 30-40% of diabetic person. The aim of this work is to contribute the useful information in the therapy of diabetes. It is very important to know the role of antioxidants at the molecular level during diabetes. The protecting role of antioxidants against lipid peroxidation, the effect of cellular antioxidant enzyme systems, understanding the changes of membrane fluidity, lipid order and protein structure which are resulted from antioxidant treatment, determining the effective therapeutic dose with the help of biochemical methods are very important in order to understand the effect of antioxidants at molecular level. In this thesis work, the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) was used in order to study the diabetic kidney disease at the molecular level, which is encountered as a complication of diabetes. Furthermore, the protecting and possible therapeutic role of selenium in the course of diabetic kidney disease was investigated. To conclude, the kidney plasma membranes were severely deteriorated due to diabetes with respect to its lipid, protein and carbohydrate structure and content, which were corrected after selenium treatment. The diabetes causes diminishment of whole membrane fluidity, which was normalized with the selenium administration. This is the first study demonstrating the effect of diabetes on kidney plasma membrane and the effect of selenium on stz-induced diabetic kidney plasma membranes using spectroscopic tools. The study revealed serious therapeutic and preventing capacities of selenium on diabetic kidney plasma membranes which needs confirmation of future researches. Furthermore, the dosage of selenium given to diabetics should be investigated in detail and proved with biochemical and clinical data.

The aim of this Ph.D. thesis was to analyze the morphine-induced changes of frontal brain cortex protein composition in rats exposed to increasing doses of morphine (10-50 mg/kg) for prolonged period of time (10 days). The first part of this work was oriented to the analysis of the phenomenon of hypersensitization/superactivation of adenylyl cyclase (AC), which is regarded as one of the crucial molecular mechanisms causing drastic pathological consequences of drug addiction. The increase of AC activity represents a "compensatory" response and is functionally related to the desensitization of G protein response to prolonged morphine exposure of target cells. The clear desensitization of µ-OR- and δ-OR-stimulated G protein response by morphine was demonstrated in our laboratory by analysis of the dose-response curves of DAMGO and DADLE-stimulated, high-affinity [35 S] GTPγS binding in plasma membranes isolated from frontal brain cortex of rats exposed to morphine according to the same protocol as that used in my Ph.D. thesis (10-50 mg/kg, 10 days). The κ-OR-stimulated [35 S] GTPγS binding was unchanged. It has been determined the amount of all AC isoforms (AC I-IX) in plasma membranes (PM) isolated from control and morphine-treated rats which were sacrificed 24 hours since the last dose of morphine....