Le dopage du silicium par implantation ionique pour le photovoltaïque est une application relativement récente dont l'essor se heurte encore aujourd'hui aux coûts élevés d'intégration au sein des lignes de fabrication des cellules solaires. L'implantation ionique par immersion plasma promet de répondre aux futures exigences du secteur en termes de coûts et de productivité.Ces travaux de thèse ont permis le développement de procédés d'implantation ionique par immersion plasma de l'équipement PULSION®, conçu par IBS, dédiés à la fabrication de cellules solaires en silicium monocristallin. Dans un premier temps, nous montrons qu'il permet la réalisation de profils de dopage d'émetteur de type n variés, répondant aux exigences des cellules solaires à haut rendement. Les émetteurs fabriqués sont caractérisés de manière chimique, physique et électrique afin de démontrer leur excellente qualité. L'intégration de l'implantation ionique des émetteurs au sein d'un processus de fabrication industriel et peu coûteux, développé par l'INES sur silicium monocristallin de type p, permet d'atteindre des rendements de conversion supérieurs à 19,3%, soit un gain de plus de 0,5% par rapport aux rendements obtenus avec des cellules usuelles à émetteurs dopés par diffusion POCl3.La réalisation d'émetteurs de type p est également étudiée dans ce mémoire afin de préparer la transition technologique vers les cellules solaires sur silicium monocristallin de type n. Confirmant les atouts et le potentiel de la technologie d'implantation ionique par immersion plasma, les travaux menés au cours de cette thèse débouchent sur la conception d'un prototype industriel PULSION® dédié au photovoltaïque. / Ion implantation is a major process technology for manufacturing integrated circuits. However, silicon doping by ion implantation for photovoltaics is a relatively recent application, and its growth still faces high costs of integration into solar cell production lines. Plasma-immersion ion implantation (PIII) promises to meet the future industry requirements in terms of costs and productivity.This thesis work has led to the development of processes dedicated to silicon-based solar cell manufacturing using the plasma-immersion ion implanter – PULSION® – designed by IBS. First, we show that PIII enables the realization of various doping profiles for phosphorus-doped emitters which fit the requirements of high-efficiency solar cells. Emitters thus fabricated are chemically, physically and electrically characterized to demonstrate their excellent quality. Those emitters, implanted through plasma immersion and integrated into a low cost solar cell manufacturing line from INES on monocrystalline silicon, enable to raise the conversion efficiency, obtained with conventional POCl3-diffused solar cells, by more than 0.5% absolute to reach efficiencies above 19.3%.Fabrication of p-type boron implanted emitters is also studied in order to improve conversion efficiencies of p-type silicon based solar cells, but also in order to anticipate the technological shift from p-type to n-type silicon material. Thanks to this thesis work, the strength and potential of PIII for photovoltaic applications have been proven and this has convinced IBS to design a PULSION® equipment dedicated to solar cell manufacturing.

Ce travail de thèse a été consacré au développement d’un système multicouche constitué de nanoparticules dopées par des ions terres rares (le cœur), entourées d’une première couche cristalline non dopée, permettant de préserver les propriétés optiques du cœur. Une coquille de silice mésoporeuse est ensuite déposée, permettant l’incorporation d’un photosensibilisateur (ZnPc) via les pores de la couche de silice pour une application thérapeutique : la photothérapie dynamique. Différentes matrices ont été étudiées à savoir Y2O3, KY3F10 et NaYF4. Ces matrices ont été codopées Yb3+/Er3+ afin d’obtenir des émissions dans le visible sous l’effet d’une excitation infrarouge (upconversion), le but ultime étant d’exciter le ZnPc in situ. Chacune des matrices a été caractérisée d’un point de vue structural et morphologique dans une première partie, et d’un point de vue spectroscopique dans une deuxième partie. La structure cœur-coquille cristalline renforce l’émission rouge issue du niveau 4F9/2 de l’Er, effet déduit de l’analyse des spectres et de la dynamique de luminescence.La détection de l’oxygène singulet a été réalisée par le protocole de « bleaching » en présence ou pas du ZnPc en évaluant l’intensité de fluorescence de l’ABDA. / This work has been dedicated to the development of a multistep system composed by rare earths doped nanoparticles (core), enclosed by a first undoped crystalline layer (core-shell), serving as protection of the optical properties of the core. Within a shell of mesoporous silica allowing the loading of the photosensitizer (ZnPc) via the pores of the shell of silica for a therapeutic application: the photodynamic therapy. Various lattices were studied namely Y2O3, KY3F10 and NaYF4. These lattices were codoped with Yb3+ and Er3+ ions to obtain emissions in the visible under an infrared excitation (up conversion), the ultimate purpose being to excite in situ ZnPc. Each of these lattices was characterized from a structural and morphological point of view in the first part and, in the second part, spectroscopic studies are developed. The core-shell enhances the red emission stemming from the level 4F9/2 of Er, effect deduced from the analysis of spectra and the dynamics of luminescence. The detection of the singlet oxygen was realized in vitro by the study of the bleaching of ABDA fluorescence. The comparison of the results for nanoparticles loaded with ZnPc and unloaded ones allows demonstrating the generation of singlet oxygen by exciting in the infrared region of the spectra thanks to the efficient upconversion processes occurring in the rare earth doped materials.

La fragilisation par l’hydrogène est une des causes les plus évoquées lors de la rupture prématurée des pièces métalliques. Il est donc nécessaire de clarifier l’effet de ce soluté sur les propriétés mécaniques et les mécanismes de plasticité dans ces matériaux. L’étude proposée de cette thèse consiste à étudier l’effet de l’hydrogène sur la réponse mécanique du nickel monocristallin déformé par la fatigue de l’échelle macroscopique jusqu’à l’échelle atomique. A l’échelle macroscopique, des essais de fatigue ont été réalisés sur du nickel orienté en glissement multiple avec plusieurs teneurs en hydrogène pour évaluer ses conséquences sur l’écrouissage cyclique du métal. Ensuite, une caractérisation microstructurale des hétérogénéités développées par la fatigue a été conduite pour plusieurs amplitudes de déformation plastique sur le nickel avec et sans hydrogène. La déformation du métal induit une organisation de la microstructure sous forme de chenaux et de murs qui dépend en partie des interactions élastiques entre l’état de contrainte, l’hydrogène et les défauts cristallins. Par conséquent, l’impact de l’hydrogène sur les propriétés élastiques du métal a été étudié à l’aide de calculs à l’échelle atomique et complété par des expériences. D’autres calculs à cette échelle, associés à des modèles analytiques basés sur la théorie élastique des dislocations, ont été réalisés pour évaluer la stabilité des structures de dislocations induites par la fatigue en présence d’hydrogène, de lacunes et d’amas de lacunes. Les principales conclusions de cette étude proviennent d’une analyse multi-échelle des résultats obtenus par la combinaison d’approches numériques et expérimentales. Nous suggérons que l’incorporation de l’hydrogène induit un durcissement intrinsèque du nickel. Cependant, la formation de lacunes et d’amas de lacunes atténue l’effet du soluté et participe à la compétition entre adoucissement et durcissement du nickel à l’échelle macroscopique. / Hydrogen in metals can lead to irreversible damages on engineering structures. Consequently, the effects of the solute on the mechanical properties and the plasticity mechanisms of these materials have to be clarified. The proposed study consists to investigate the effects of hydrogen on the mechanical response of nickel single crystal strained by fatigue from macroscopic scale down to the atomic scale. At macroscopic scale, cyclic tests are conducted on multi-slip oriented nickel with several hydrogen concentrations to evaluate its consequences on the cyclic hardening of the metal. Then, a microstructural characterisation of the heterogeneities developed by fatigue is conducted for several plastic deformation amplitudes on nickel with and without hydrogen. The deformation of the metal induces a microstructure in form of wall and channel phases, which partially depend on the elastic interactions between the stress state, hydrogen and the induced crystalline defects. Therefore, the impact of hydrogen of the elastic properties of nickel single crystal is investigated using atomic scale calculations and experiments. Further calculations at this length scale associated with analytical elastic models are conducted to evaluate the stability of fatigue induced dislocation structures in presence of the solute, vacancies and vacancy clusters. The main conclusions of this study arise from the analysis of the results obtained from macroscopic scale down to the atomic scale and from the combination of both numerical and experimental techniques. In particular, the incorporation of hydrogen leads to a hardening of the nickel intrinsically. However, the formation of vacancies and vacancy clusters by the incorporation of hydrogen counteracts the effects of the solute and participates in the competition between the softening and the hardening of cyclically strained nickel single crystal observed at macroscopic scale.

Neste trabalho são estudados os mecanismos de desgaste, atuantes na escala do tamanho de grão (meso-escala), durante ensaios de cavitação vibratória, para diferentes amostras de aços inoxidáveis austeníticos ligados com nitrogênio. Amostras com teores superficiais de nitrogênio de aproximadamente 0, 9 % massa, 1, 4%massa e 20%massa, obtidas a partir do a¸co inoxidável dúplex UNS S31803, foram estudadas. As amostras do a¸co inoxidável duplex UNS S31803, com aproximadamente 0, 9 % N massa, foram obtidas por nitretação gasosa em alta temperatura (temperatura de nitretação entre 1050 e 1200 C) e consistiram em três grupos diferentes: amostras com nitrogênio em solução sólida e solubilizadas, amostras com precipitação de nitretos e amostras com nitrogênio em solução sólida e encruadas. Já as amostras com teor de nitrogênio próximo de 20 % N massa foram processadas por meio de nitretação a plasma na temperatura de 400 C, obtendo-se uma camada superficial de austenita expandida. As amostras de ensaio foram submetidas à caracterização de textura por difração de elétrons retroespalhados, EBSD, e posteriormente à cavitação vibratória em ´agua destilada. Os ensaios de cavitação foram periodicamente interrompidos com o intuito de estudar a deteriora¸cao das amostras por exame das mesmas no microscópio eletrônico de varredura, MEV, e por medidas de perda de massa. Quando comparadas com os aços inoxidáveis austeníticos convencionais (UNS S30403 solubilizado e UNS S31803 como recebido), sem adição de nitrogênio e livre de encruamento, as amostras estudadas apresentaram resistência ao desgaste por cavitação superior, quantificada tanto pelo tempo de incubação do dano com perda de massa quanto pela taxa máxima de perda de massa nos estágios avançados do dano. A taxa máxima de perda de massa para cada tipo de amostra estudada, com relação `a taxa máxima do material de comparação, o aço inoxidável convencional sem adição de nitrogênio e livre de encruamento (UNS S30403) solubilizado, foi de: amostras com precipitação de nitretos (318HTGN+Nit), 6,9 vezes menor; amostras com nitrogênio em solução sólida e solubilizadas (318HTGH+Sol) e laminadas e solubilizadas (318HTGN+Lam+Sol), 26,8 e 25 vezes menor, respectivamente; amostras com nitrogênio em solução sólida e encruadas (318HTGN+Enc) 145 vezes menor; e amostras com camada superficial de austenita expandida (obtidas por nitretação a plasma), (318HTGN+Plas e 304LSol+Plas) 290 e 1,77 e vezes menor respectivamente. O efeito benéfico da adição de nitrogênio na resistência à erosão por cavitação dos aços inoxidáveis austeníticos estudados foi atribuído a: (i) aumento na resistência à deformação plástica; (ii) distribuição mais homogênea da deformação plástica induzida pelas ondas de choque e micro-jatos característicos do processo de cavitação; e (iii) aumento da importância relativa dos mecanismos de perda de massa com elevado consumo de energia de impacto. Nos primeiros estágios do dano erosivo por cavitação se observou clara evidência de deformação plástica, acompanhada de formação de microreelevo superficial e de protrusão de bandas de escorregamento. A perda de massa em nível microscópico (observações no MEV) começa como destacamento de material em microtrincas e micropites. Observou-se que tanto a nucleação do dano como o seu crescimento se apresenta de forma heterogênea na escala do tamanho de grão. Os sítios microestruturais nos quais se iniciou o dano com perda de massa foram preferencialmente protuberâncias nas protrusões de bandas de escorregamento, protuberâncias nos contornos de grão e as interfaces matriznitreto. O incremento do teor de nitrogênio (em solução sólida) na amostra aumentou a importância relativa dos contornos de grão como locais de nucleação do dano, em relação ao dano iniciado no interior dos grãos. Observou-se que o interior dos grãos com planos 100 ou 111 orientados de forma aproximadamente paralela à superfície das amostras são regiões muito suscetíveis à incubação do dano e ao crescimento do mesmo. Já os grãos com planos 101 orientados aproximadamente paralela à superfície das amostras, apresentam regiões com resistência ao dano bem maior. Esses resultados são discutidos, considerando as diferenças de tensão (resultantes da ação de ondas de choque causadas pela implosão de bolhas de cavitação) crítica projetada para cisalhamento de grãos com diferentes orientações. O dano ocorre preferencialmente em contornos de grãos com acentuados gradientes de tensão resolvida para a deformação plástica, onde se desenvolve elevada concentração de tensões. Em particular, os contornos de macla CSL 3 são acentuadamente mais suscetíveis à incubação do dano que os outros tipos de contornos CSL e que os contornos não CSL. / High nitrogen austenitic stainless steels containing 0.9 wt-% N and 20 wt- % N were tested in a ultrasonically induced vibratory cavitation testing device. Incubation times for damage initiation and mass losses were periodically measured during the cavitation-erosion tests. Scanning Electron Microscopy observation of the damaged surfaces allowed identifying the wear mechanisms operating during each step of the cavitation-erosion test. 0.9 wt-% N specimens were obtained through High Temperature Gas Nitriding UNS S31803 duplex stainless steel, at temperatures between 1050 and 1200 oC. Three groups of specimens were obtained: solubilized with all nitrogen in solid solution, solubilized and work hardened specimens and nitride containing specimens. The 20 wt- % N specimens were obtained through Low Temperature Plasma Nitriding the already High Temperature Gas Nitrided specimens and getting an expanded austenite layer at the surface. The specimens were firstly characterized by Electron Backscattered Diffraction - EBSD techniques and then submitted to the cavitation-erosion tests in distilled water. When compared to conventional UNS S30403 lean nitrogen solubilized austenitic stainless steel specimens, greater incubation times and smaller maximum wear rates were observed. The maximum wear rates (compared to those of the solubilized UNS S30403 steel) were: for the nitride containing specimen 6.9 times smaller; for textured and non-textured all nitrogen in solid solution specimens 26.8 and 25 times smaller, respectively; for the solubilized and work hardened specimen 145 times smaller; for the expanded austenite layer, with circa 20 wt- % N, specimens 300 times smaller. The beneficial effect of nitrogen on the cavitation-erosion resistance of the studied specimens was attributed to: (i) an increase in resistance to plastic deformation; (ii) a more homogeneous distribution of the plastic deformation; and (iii) an increase of the relative participation of energy consuming mass loss mechanisms. Plastic deformation accompanied by formation of micro relief at the surface and slip bands protrusions were clearly identified, during the first stages of cavitation erosion. The first evidences of mass loss (detected by SEM observations) were seen as particles detaching from micro cracks and micro pits formed at the grain surface. Nucleation and growth of cavitation damage was heterogeneously distributed at the grain scale. Slip bands protrusions, grain boundary protrusions and nitride matrix interfaces sites were more prone to nucleating the damage. Increasing nitrogen contents in solid solution increased the relative contribution of grain boundary nucleated damage, compared to the total amount of nucleation sites. Grains with 100 and 111 crystallographic planes approximately parallel to the surface were more prone to nucleation and growth of cavitation damage. Grains with 101 planes // surface were much more resistant to cavitation-erosion damage. These results are discussed considering differences of critical resolved shear stresses for grains with different orientations. Cavitation erosion damage occurs preferentially at grain boundaries across which steep stress gradients arise. Particularly, CSL -3 twin boundaries are much more susceptible to cavitation erosion damage incubation than other types of CSL boundaries and non CSL boundaries.

Observa-se atualmente uma evolução significativa do conhecimento nas áreas relacionadas às geociências. E, em particular a ciência geomorfológica, a qual tem como premissa compreender e explicar as formas da arquitetura do relevo na atualidade através de sua gênese, evolução cronológica e grau de estabilização partindo de estudos descritivos e investigativos. Tais avanços estão respaldados em novas geotecnologias e consequentemente na aplicação de metodologias específicas que permitem uma vasta possibilidade de novas pressuposições indicativas ou elucidativas sobre o sistema geomorfológico. Desta forma este trabalho tem como objetivo averiguar qual a possível influência dos aspectos geoquímicos sobre o estado atual das unidades de relevo associados aos fatores e elementos geoambientais, em litologias diferenciadas através da aplicação de procedimentos metodológicos envolvendo a utilização de geotecnologicas e investigações geoquímicas. Para a realização e êxito desta proposta metodológica definiu-se coma área de estudo a bacia hidrográfica do rio Pequeno em seu terço médio e superior, situada no município de São José dos Pinhais, integrante da Região Metropolitana de Curitiba no Estado do Paraná região sul do Brasil. Optouse por este recorte espacial em função do mesmo apresentar as características geoambientais apropriadas para o desenvolvimento deste trabalho. Os procedimentos metodológicos adotados consistem na utilização da análise de produtos elaborados a partir das técnicas do sensoriamento remoto e geoprocessamento para a confecção da cartografia temática. Produtos estes associados à investigação geoquímica do material de alteração (saprólito) em rochas do embasamento cristalino tomando como objeto de estudo vertentes contra postas uma em relação a outra em duas áreas amostrais distintas. Para a investigação geoquímica optou-se pelo método da varredura semi-quantitativa dos óxidos através da espectrometria de fluorescência de raios “X" em amostras de materiais intermediários entre os estudos geoquímicos orientativos do solo e litogeoquímicos orientativos. Considera-se que para os ensaios metodológicos a que se propõe este trabalho os resultados foram satisfatórios com a ressalva para a importância de estudos mais detalhados, envolvendo mais análises propiciando assim maior confiabilidade nas correlações geoquímicas com a interpretação e compreensão das formas do relevo atual. Entretanto ressalta-se a importância destes resultados não como respostas elucidativas e sim como mais uma possibilidade metodológica investigativa viável para a compreensão do sistema geomorfológico quanto sua gênese, evolução e grau de estabilidade. / A significant evolution of knowledge on geosciences and its related topics can be observed nowadays. It happens, in particular, with the geomorphologic science, which has, as its premise, to understand and to explain the current relief architecture form based on its genesis, chronological evolution and stabilization degree having, as starting point, descriptive and investigative studies. Such developments are supported by new geotechnologies and, consequently, by the application of specific methodologies that allow a broad possibility of new indicative or elucidative propositions about the geomorphologic system. Therefore, the objective of this work is to verify the possible influence of geochemical aspects on the current relief units’ state related to geoenvironmental elements, in different lithologies through the application of methodological procedures involving the application of geotechnologies and geochemical research. In order to successfully accomplish this methodological proposal the higher third mean of the “Pequeno" river watershed was defined as the area of study. This area is located in São José dos Pinhais municipality in the Curitiba metropolitan area, in Paraná state, in south region of Brazil. Such special cut was adopted because of the suitability of its geoenvironmental characteristics to the right and proper execution of this work. The adopted methodological procedures consist in the use of the analysis of products prepared based on remote sensing techniques and geoprocessing in order to produce the thematic cartography. Such products are associated to the geochemical research of the alteration material (saprólito) in the crystalline basement rocks, having as object of interest opposed strands in two distinct sample areas. When concerning the geochemical study, the oxide semi-quantitative scan method using x-ray fluorescent spectrometry was adopted. It was performed in intermediate material samples between the geochemical orientated and lithogeochemical orientated soil studies. Considering the methodological essays proposed in this work, the obtained results are satisfactory. It is important, however, to perform more detailed studies with more analysis with the purpose of having more confidence regarding the geochemical relations with the interpretation and understanding of the current relief forms. Nevertheless, it is important to stress the importance of these results, not as clarifying answers, but as another feasible possibility to understand the geomorphologic system regarding its genesis, evolution and stability degree.

O mecanismo de interferência por RNA (RNAi) é um evento de silenciamento gênico através da degradação do RNA mensageiro. Desta forma, a administração de siRNA (molécula efetora do RNAi) é uma terapia promissora para o tratamento de diversas doenças como o câncer. Porém, para a sua efetiva aplicação terapêutica é necessário o desenvolvimento de sistemas de liberação capazes de liberar o siRNA nas células alvo, promover a sua internalização celular e evitar a sua degradação. Dentre os sistemas de liberação, os de liberação localizada, como os sistemas de geleificação in situ, apresentam vantagens sobre administração sistêmica. Formulações fluidas precursoras (FFP) que formam sistemas líquido cristalinos viscosos in situ podem ser obtidas a partir de lipídeos anfifílicos que absorvem água do meio e se rearranjam. Neste contexto, a presente pesquisa teve como objetivo avaliar o gel formado in situ a partir da FFP (G-FFP), composta por monoglicerídeos (MO), polietilenoimina (PEI), propilenoglicol (PG) e tampão tris, como sistema de liberação localizada de siRNA na terapia do câncer de pele. Os resultados mostraram que o G-FFP é uma mistura de fase cúbica e fase hexagonal. O G-FFP liberou o siRNA de maneira sustentada e complexado ao PEI. A FFP pode ser esterilizada por filtração em membrana e foi capaz de complexar altas concentrações de siRNA (15 mM) e de proteger o siRNA da degradação. A citotoxicidade foi dependente da concentração de FFP e esta quando complexada com siRNA teve a toxicidade diminuída. O siRNA liberado do G-FFP foi internalizado pelas células A431, FaDu, HeLa, A549, WM35/DLC2-GFP e MCF-7/DLC2-GFP. Além disto, siRNAs específicos liberados pelo G-FFP foram capazes de reduzir a expressão da proteína Firefly luciferase em células HeLa e FaDu, pórem não foram capazes de reduzir a expressão do receptor do fator de crescimento epidérmico (EGFR) nas células A431, HeLa, A549 e FaDu. A redução da expressão de EGFR em células A549 foi observado quando a terapia com siRNA foi combinada com internalização fotoquímica. Destes resultados, pode-se inferir que a transfecção celular do siRNA e o silenciamento gênico promovido por ele foi dependente tanto do tipo de linhagem celular como do alvo desejado. Os estudos in vivo mostraram que ocorre a formação de gel intratumoral e após 3 dias da administração intratumoral da FFP contendo siRNA específico para EGFR houve redução de 30% no tamanho dos tumores comparados aos tumores tratados com FFP sem siRNA. Diante destes resultados, pode-se concluir que o sistema desenvolvido tem potencial como sistema de liberação localizada de siRNA quando aplicado subcutaneamente ou intratumoral, uma vez que complexa o siRNA, promove a sua internalização celular e o siRNA liberado no citoplasma das células pode reduzir a expressão de proteínas de interesse. / RNA interference (RNAi) is a mechanism in which small interfering RNA molecules (siRNA) inhibit gene expression, by causing the messenger RNA degradation. Thus, siRNA is a promising therapy for the treatment of several diseases such as cancer. However, the development of delivery systems able to protect the siRNA from degradation and promote its cell uptake is essential for therapeutic use of siRNA. Among the delivery systems, the localized delivery system such as in situ gelling delivery system, have advantages over systemic administration. Precursor fluid formulations (FFP), which forms in situ viscous liquid crystalline systems, can be obtained from amphiphilic lipids that absorb water from the environment and self-assembling. In this context, the present study aimed to evaluate the in situ gel formed from the FFP (G-FFP), composed of monoglycerides (MO), polyethyleneimine (PEI), propylene glycol (PG) and Tris buffer, as localized delivery system for siRNA in skin cancer therapy. The results showed that the G-FFP is a mixture of cubic and hexagonal phase. The G-FFP sustained release of siRNA and the siRNA is released complexed with PEI. The FFP can be sterilized by membrane filtration at 0.22 ?m. FFP was able to complex high siRNA concentration (15 mM) and protect the siRNA from degradation. The cytotoxicity was dependent on the FFP concentration, when FFP was complexed with siRNA it was observed a decreased in toxicity. The siRNA released from G-FFP was uptake by A431, FaDu, HeLa, A549, WM35/DLC2-GFP and MCF-7/DLC2-GFP cells. In addition, specific siRNAs released from G-FFP were able to reduce the expression of Firefly luciferase in HeLa and FaDu cells, but they were unable to reduce the expression of the epidermal growth factor receptor (EGFR) in A431, HeLa, A549 and FaDu cells. The reduction of expression of EGFR in A549 cells was observed when siRNA therapy was combined with photochemical internalization. From these results, can be inferred that the efficiency of siRNA transfection and knockdown was dependent on both the type of cell line and the desired target protein. In vivo studies showed that the gel was formed in situ after intratumoral injection. 3 days after intratumoral administration of FFP containing EGFR specific siRNA, 30% of reduction in the tumors size compared to tumors treated with FFP without siRNA was observed. Based on these results, could be concluded that the developed system is a potential siRNA delivery system when administered subcutaneously and intratumoral, because it was able to complex siRNA, promoted its cell uptake and the siRNA released into the cytoplasm of the cell may reduce the expression of target proteins

Ce travail porte sur l’étude et la réalisation d’une cellule d’allumage laser pour turbomoteurs. Une étude bibliographique nous a permis d’identifier les caractéristiques nécessaires : des impulsions nanosecondes d’au moins 10mJ. La spécificité de l’application impose de nombreuses contraintes qui ont influencé le choix d’une architecture avec deux étages amplificateurs : un amplificateur fibré suivi d’un amplificateur à base de fibre cristalline. Nous avons développé un code permettant de simuler l’amplification d’une impulsion nanoseconde dans ces milieux et ainsi déterminé les caractéristiques techniquesoptimales de chaque étage amplificateur. Ces résultats ont permis la réalisation d’une chaîne d’allumage et sa caractérisation. Une étude particulière del’amplificateur fibré a permis de maîtriser l’apparition d’effets non-linéaires limitants. Finalement, nous démontrons le potentiel de notre solution laserpar plusieurs campagnes d’allumage sur différents bancs moteurs. / This work deals with the design and the construction of a laser ignitionsystem for turbine engines. A review of the dedicated literature allowed us toidentify the required characteristics : nanosecond pulses with at least 10 mJ ofenergy. Our specific application imposes numerous constraints which directlyinfluenced our choice of two amplifier stages : a fiber amplifier followed by acrystalline-fiber based amplifier. We developped a simulation describing theamplification of nanosecond pulses through these two medias and thus de-termined the optimal technical characteristics of each amplifier stage. Theseresults lead to the realization of an laser ignition system that we completelycharacterised. A specific study of the fiber amplifier allowed us to understandand control the appearance of non-linear limiting phenomena. Eventually, wedemonstrate the capabilities of our solution by several laser-ignition field stu-dies.

The primary reason for incorporating pigments into plastic materials is to impart the desired colour to finished articles. Some pigments however, may interact with the polymer leading to unexpected deleterious effects. Organic pigments, especially phthalocyanines, are favourable for their brilliant shade but are also well known for causing part distortion or warpage. This causes problems in parts which require good dimensional stability such as crates, containers, trays, caps and closures. Despite that, there are not many published studies on the root cause and mechanism of warpage induced by the pigment. Hence, the objective of this research is to study the influence of such pigments on the dimensional stability, crystallisation behaviour and morphology of polyethylenes in order to have a better understanding on the mechanism of warpage, which could possibly lead to a solution in overcoming this problem.

Apesar de extensa investigação das modificações oxidativas irreversíveis sofridas pelas proteínas in vitro e in vivo, os produtos formados pela oxidação de resíduos de triptofano ainda permanecem apenas parcialmente conhecidos. Recentemente, nosso grupo caracterizou uma ligação cruzada de ditriptofano produzida pela recombinação de radicais hSOD1-triptofanila gerados pelo ataque do radical carbonato produzido durante a atividade peroxidásica da enzima superóxido dismutase humana (hSOD1). Neste trabalho, examinamos se a ligação ditriptofano pode ser formada em outras proteínas, além da hSOD1 e por outros oxidantes, além do radical carbonato. A lisozima da clara do ovo e a beta cristalino bovina foram utilizadas como alvos de oxidação. A lisozima foi utilizada por ser uma enzima pequena (129 aminoácidos) e de estrutura bem conhecida, contendo seis resíduos de Trp. Os resultados mostraram que o radical carbonato, gerado enzimatica ou fotoliticamente, promove a oxidação, dimerização e inativação da lisozima. Os principais produtos de oxidação caracterizados por análise de nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano e N-formilquinurenina juntamente com um dímero de lisozima (lisozima-Trp28-Trp28-lisozima) e um hetero dímero lisozima-hSOD1 (lisozima-Trp28-Trp32-hSOD1), ambos ligados por uma ligação ditriptofano. Também demonstramos que a irradiação da lisozima com luz UVC leva à formação do dímero lisozima-Trp28-Trp28-lisozima. Em consequência, resolvemos tratar a beta cristalino bovina com radical carbonato gerado fotoliticamente ou com luz UVC, e a proteína também sofreu oxidação, dimerização e agregação. Os principais produtos de oxidação caracterizados por nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano, N-formilquinurenina, DOPA e um dímero de beta cristalino (βB2-Trp151-Trp151-βB2). A irradiação com luz UVC também levou à formação de um dímero intra-cadeia, caracterizado como βA2-Trp78-Trp81. Quando a beta cristalino foi irradiada com um simulador de luz solar (UVA e UVB) também foi possível observar um dímero, caracterizado como βA2-Trp150-Trp150-βA2. A presença de produtos de oxidação de resíduos de Trp, dentre eles a ligação cruzada ditritpofano, também foi avaliada in vivo, utilizando o cristalino de pacientes que foram submetidos a cirurgia para remoção de catarata. Beta, alfa e gama cristalino foram as principais proteínas identificadas nas frações solúvel e insolúvel do cristalino. A principal modificação pós-traducionais identificada foi deamidação. Um alto conteúdo de resíduos de metionina e triptofano oxidados foram identificados nas proteínas presentes na fração insolúvel. Os principais produtos de oxidação de Trp identificados por nano-ESI-Q-TOF-MS/MS foram quinurenina e N-formilquinurenina. A presença de dímeros covalentes no cristalino com catarata foi confirmada por análises de massas. A completa caracterização desses dímeros (βB1-Trp127-Trp127-βB1 e βB1-Trp193-Trp193-βB1) confirmou que as cadeias polipeptídicas foram ligadas por uma ligação ditriptofano. Em síntese, nossos dados demonstraram que o radical carbonato e a luz UV podem produzir dímeros de ditriptofano em diferentes proteínas. Também, a presença da ligação cruzada de ditriptofano in vivo (catarata humana) foi pela primeira vez detectada. / Despite extensive investigation of irreversible oxidative modifications suffered by proteins in vitro and in vivo, the products formed by oxidation of tryptophan residues remain partially characterized. Our group recently described a ditryptophan cross-link produced by recombination of hSOD1-tryptophanyl radicals generated by attack of the carbonate radical produced during the peroxidase activity of the human superoxide dismutase (hSOD1) enzyme. Here, we examine whether the ditryptophan cross-link can be produced in others proteins besides the hSOD1 and by other oxidants, in addition to the carbonate radical. The egg white lysozyme and bovine beta crystalline were used as targets. Lysozyme was used because it is a small enzyme (129 amino acids) with a well-known structure, containing six Trp residues. The results showed that the carbonate radical, generated enzymatically or photolytically, promotes lysozyme oxidation, inactivation and dimerization. The major oxidation products characterized by nano-ESI-Q-TOF-MS/MS analysis were hydroxy-tryptophan and N-formylkynurenine together with a dimer of lysozyme (lysozyme-Trp28-Trp28-lysozyme) and a hetero dimer hSOD1-lysozyme (lysozyme-Trp28-Trp32-hSOD1), both bound by a ditryptophan cross-link. Also, it was demonstrated that lysozyme irradiation with UVC light leads to the formation of the dimer lysozyme-Trp28-Trp28-lysozyme. In view of these results, we decided to treat beta crystalline bovine with photolytically generated carbonate radical and UVC. Beta crystalline also suffered oxidation, dimerization and aggregation. The major oxidation products characterized were hydroxy-tryptophan, N-formylkynurenine, DOPA and a beta crystalline dimer (βB2-Trp151-Trp151-βB2) by nano-ESI-Q-TOF-MS/MS. Irradiation with UVC light also led to the formation of an intra-chain dimer, which was characterized as βA2-Trp78-Trp81. When beta crystalline was irradiated with a solar simulator (UVA and UVB), it was also possible to observe a dimer which was characterized as βA2-Trp150-Trp150-βA2. The presence of oxidized tryptophan products, including the ditryptophan cross-link, was also evaluated in vivo in the lenses of patients submitted to cataract removal. Beta, alpha and gamma crystalline were the main proteins identified in soluble and insoluble fractions of the lenses. The main post translational modification identified was deamidation. A high content of oxidized methionine and tryptophan residues were identified in proteins present in the insoluble fraction. The main tryptophan oxidation products identified by nano-ESI-Q-TOF-MS/MS were kynurenine and N-formylkynurenine. The presence of covalent dimers in the lenses with cataract was demonstrated by mass analysis. Full MS/MS characterization of the dimers βB1-Trp127-Trp127-βB1 and βB1-Trp193-Trp193-βB1 confirmed that they were linked by a ditryptophan bond. In summary, our data demonstrate that the carbonate radical and UV light can produce ditryptophan dimers in different proteins. Also, the presence of the ditryptophan cross-link was first detected in vivo (human cataract).

Les facteurs qui régissent l'intensité et la répartition de la recharge naturelle et artificielle dans les aquifères cristallins altérés et fracturés sont mal connus. Ce sont cependant les caractéristiques déterminantes de ce type de roche—ces roches sont très hétérogènes—qui rendent difficile l’estimation des flux dans ces milieux ainsi que des propriétés hydrauliques qui les contrôlent. La première partie de ce manuscrit fournit un état des connaissances sur la recharge des eaux souterraines et ses méthodes d’estimation, permettant de comprendre les défis scientifiques et sociétaux abordés dans cette thèse. La deuxième partie présente les travaux numériques et expérimentaux menés pour approfondir notre compréhension de la dynamique des flux d’eaux souterraines dans ces milieux hétérogènes à plusieurs échelles. Le premier axe de recherche porte sur les processus de recharge naturelle à l’échelle du bassin versant. La recharge diffuse a été modélisée avec un modèle physique simple d’infiltration et comparée à des estimations préalables de recharge totale. Nos résultats illustrent la forte dépendance de la recharge aux précipitations et à l’irrigation, et l’importance de la recharge focalisée. Les facteurs responsables de la distribution spatiale de la recharge sont aussi étudiés. Le deuxième axe est basé sur le suivi de la mise en eau d’un bassin de recharge artificielle dans un site hautement monitoré et bien équipé. Ces observations ont été interprétées avec des modèles analytiques et numériques. Ces modèles ont mis en évidence l’existence de flux préférentiels horizontaux, mais aussi d’une compartimentation latérale qui entrave la propagation des intrants de recharge. / The factors governing the intensity and distribution of natural and artificial recharge in weathered and fractured crystalline aquifers are poorly understood. However, it is the defining characteristics of this type of rock—these rocks are very heterogeneous—that make the estimation of fluxes and the hydraulic properties controlling them difficult. The first of its two parts provides the theoretical framework on groundwater recharge processes and its estimation methods for comprehending the scientific and societal challenges discussed in this thesis. The second part presents the numerical and experimental work carried out to deepen our understanding of the dynamics of groundwater flows in these heterogeneous underground environments at several scales. The first line of research focuses on natural recharge processes at the watershed scale. Diffuse recharge was modeled with a simple physical infiltration model and compared to previous estimates of total recharge. Our results highlight the strong dependence of recharge on rainfall and irrigation, and the importance of focused recharge. The factors responsible for the spatial distribution of recharge are also studied. The second axis is based on the monitoring of the filling of an artificial recharge basin at a highly monitored and well-equipped site. These observations were interpreted with analytical and numerical models to improve our knowledge of flow dynamics in fractured crystalline rocks at the medium scale. These models illustrated the existence of preferential horizontal flows, but also of a lateral compartmentalization that hinders the propagation of recharge inputs.