Sistemas push-pull são caracterizados pela presença de uma transição eletrônica de transferência de carga, o que justifica a grande diferença de polaridade entre os estados fundamental e excitado. Isso os torna sondas moleculares promissoras para a obtenção de informações espectroscópicas sobre a fase condensada. Alguns desses sistemas apresentam modos vibracionais cuja frequência depende da energia de excitação nos espectros Raman. Neste estudo, através de uma sonda molecular push-pull, objetivou-se analisar as características do meio que definem tal dependência. A sonda utilizada, 4-dimetilamino-β-nitroestireno apresentou deslocamento batocrômico no espectro de absorção eletrônico e a dependência da largura de banda com o solvente, o que mostrou sua sensibilidade ao meio, juntamente com uma dependência do modo de estiramento simétrico do grupo nitro com o solvente. Através do modelo do estado de solvatação seletivo, variando a energia de excitação do laser, foi possível observar a dependência do número de onda do modo de estiramento simétrico do NO2. Essa dependência foi, no entanto, mais significativa em solventes próticos polares, os quais apresentam os maiores valores de tempo de relaxação do solvente. Alguns solventes polares apróticos também apresentaram, mas com menor deslocamento, o que poderia estar relacionado com o tempo de relaxação. Solventes com dinâmicas de solvatação mais lentas e com forte interação, provocando uma diminuição na energia de transição eletrônica, são os principais fatores para ocorrência da dispersão Raman em sistemas push-pull. / The push-pulls systems are characcterized by the presence of a charge transfer electronic transition, it explain the large difference in polarity between the ground and excited states. They are promising molecular probes to obtain spectroscopic information on the condensed phase because of that characteristic. Some of these systems have vibrational modes whose frequency depends on the excitation energy in the resonant Raman spectra. The objective of this study was to analyze the vibrational frequency dependence of the molecular probe caused by environment. The 4-dimethylamino-β-nitrostyrene as a probe was sensitive to the medium showing bathochromic shift on electronic spectrum and bandwidth dependence with the solvent as well as the dependency of the nitro symmetric stretching mode in the vibrational spectrum. Based on the selective solvation state model, the laser excitation energy was varied and the dependence of the wave number of the symmetric stretching mode NO2 was observed. This dependency is, however, more significant in polar protic solvents which have the highest relaxation time values of the solvent. Some aprotic polar solvents presented that characteristic with less degree, which may be related to the relaxation time. The main factor for the occurrence of Raman scattering in push-pull solvation systems is the slower solvation dynamics and strong interaction that are capable to diminishing the energy electronic transition. The main factors for the occurrence of Raman dispersion in push-pull solvation systems are the slower solvation dynamics and strong probe/solvent interaction that are capable to diminishing the electronic transition energy.

Os comprimidos osmóticos do tipo bicamada ou \"push pull\" são sistemas reservatórios constituídos de um núcleo bicamada, circundado por uma membrana semipermeável e com um orifício de liberação perfurado a laser que permitem a liberação do fármaco através da cinética de ordem zero. Este sistema possui a vantagem de apresentar uma liberação controlada e não influenciada pelos fatores fisiológicos do trato gastrointestinal, permitindo aplicações terapêuticas para novos fármacos e inclusive para fármacos já existentes. O presente projeto contemplou as etapas de desenvolvimento, caracterização e avaliação de um sistema osmótico do tipo bicamada ou \"push pull\", para veiculação do atenolol, um beta bloquador de grande importância na terapia antihipertensiva. Após a padronização e validação da metodologia analítica, estudos de compatibilidade entre o fármaco e os excipientes através da análise calorimétrica e espectroscopia no infravermelho (pré-formulação), a produção, a caracterização da membrana de revestimento e, por fim, a avaliação do desempenho dos núcleos osmóticos foram realizados. Assim, três lotes, com 4kg cada, foram produzidos para determinação do peso médio e do ferramental adequados, além da proporção entre os excipientes da formulação. O processo de compressão deu origem aos núcleos osmóticos do tipo bicamada que foram submetidos à avaliação físico-química como determinação do peso médio, da dureza, da friabilidade e da espessura. Além disso, padronizou-se o processo de revestimento dos núcleos com membrana semipermeável e avaliou-se o perfil de captação de água dos núcleos resultantes (\"Swelling\"). A membrana de revestimento foi submetida à microscopia eletrônica de varredura (MEV), análise por adsorção de nitrogênio e porosimetria de mercúrio para verificação da distribuição e tamanho médio dos poros. Para a obtenção do orifício de liberação padronizou-se a quantidade de radiação a laser suficiente para perfuração da membrana semipermeável que envolve os núcleos. Após a perfuração a laser, os núcleos foram submetidos então ao estudo de liberação in vitro para avaliação da influência do diâmetro de orifícios, do número de orifícios, da espessura da membrana semipermeável, da hidrodinâmica do meio de dissolução e da influência térmica na velocidade de liberação do fármaco. A cinética do tipo ordem zero e o controle da liberação do fármaco ao longo do tempo foram alcançados com sucesso a partir dos núcleos osmóticos produzidos no lote 03. / The push pull osmotic release tablets are bilayer core reservoir systems surrounded by semi permeable membrane and with one delivery hole where the drug is released through, following zero order release kinetics. This system has many advantages and two of them are the controlled drug release and independence of physiologically factors allowing many therapeutic applications to new one and known one drugs. This exclusive work proposed the development, characterization and evaluation of atenolol push pull osmotic system that is very important to antihypertensive treatment. After analytical standardization and validation activities, the pre-formulation studies using calorimetric and infra red spectroscopy techniques, manufacturing, semi permeable membrane characterization and finally osmotic tablets performance evaluation were performed. Batches about 4 kg each one were manufactured and tablets average weight, by-layer proportionality and suitable punches were chosen. Thus the osmotic tablets obtained by bi-layer press were physical and chemical evaluated (average weight, hardness, friability, and thickness). After that the tablets were submitted to a coating process with semi permeable membrane and the uptake water profile (Swelling) was observed to characterize the membrane permeability. The semi permeable membrane was submitted also to scanning electron microscopy (SEM), nitrogen adsorption and mercury porosimetry techniques in order to characterize the porous average diameter and distribution. To produce the delivery hole in the drug layer semi permeable membrane the sufficient laser radiation amount was studied and determined. So the perforated osmotic tablets were submitted to in vitro drug release studies to evaluate the influence of hole diameter, hole number, coating thickness, medium hydrodynamic and temperature stress responsible for drug release modifications. Finally the controlled delivery and the zero order drug release kinetics were achieved successfully from osmotic tablets developed and produced in the third bath. This third bath was the result of the factors comprehension and the optimization of the early ones.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-18T14:35:18Z No. of bitstreams: 1 mariellaagostinhogoncalves.pdf: 2206097 bytes, checksum: 736acf1d28715f5b3a331257446b5b23 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-01T18:48:04Z (GMT) No. of bitstreams: 1 mariellaagostinhogoncalves.pdf: 2206097 bytes, checksum: 736acf1d28715f5b3a331257446b5b23 (MD5) / Made available in DSpace on 2016-07-01T18:48:04Z (GMT). No. of bitstreams: 1 mariellaagostinhogoncalves.pdf: 2206097 bytes, checksum: 736acf1d28715f5b3a331257446b5b23 (MD5) Previous issue date: 2012-03-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste estudo, avaliou-se a resistência da união ao push-out de dois cimentos resinosos auto-adesivos e de um cimento resinoso convencional em dentina radicular. Em 60 dentes terceiros molares humanos, tratados endodonticamente, um pino de fibra de vidro foi cimentado com um dos três cimentos resinosos. Cada raiz foi seccionada em sentido transversal para a obtenção de três fatias (dentina-pino) de 1 mm de espessura. As fatias, correspondentes aos terços cervical, médio e apical do canal radicular, foram armazenadas em água deionizada a 37 ºC, durante 24 horas ou 30 dias. Após o teste de push-out, os valores de resistência da união foram submetidos aos testes estatísticos ANOVA three way e Tuckey (p = 0,05) e os tipos de fratura foram avaliados através de microscopia eletrônica de varredura. A resistência da união do cimento resinoso auto-adesivo RelyX U100 foi superior à do cimento convencional RelyX ARC, após os dois períodos de armazenamento (p < 0,05). No terço cervical, os valores de resistência da união do cimento resinoso convencional RelyX ARC foram maiores que nos terços médio e apical (p < 0,05) na análise de 24 horas. Após 30 dias de armazenamento, os valores nos três terços radiculares não diferiram entre si. Os valores de resistência da união do cimento resinoso RelyX U100, nas três regiões do canal radicular, não diferiram entre si (p > 0,05), em ambos os momentos de avaliação. Após 24 horas, BisCem apresentou maior resistência da união no terço apical, seguido pelo terço cervical. Após 30 dias, os valores de resistência da união nos três terços radiculares não diferiram entre si (p > 0,05). RelyX U100 não sofreu alteração nos valores de resistência da união após 30 dias de envelhecimento (p > 0,05). BisCem não apresentou diferenças nos valores obtidos após 24 horas e 30 dias de envelhecimento nos terços cervical e médio (p > 0,05). Para RelyX ARC, o tempo de 30 dias reduziu os valores de resistência da união nos três terços radiculares. RelyX U100 e BisCem apresentaram maior número de falhas coesivas da zona de interação. Para RelyX ARC, observou-se maior número de falhas coesivas da camada híbrida. Concluiu-se que o cimento resinoso auto-adesivo RelyX U100 apresentou maior resistência da união que o cimento resinoso convencional RelyX ARC, nos três terços radiculares, nos dois momentos de avaliação. BisCem demonstrou resistência da união comparável a do cimento RelyX U100. O tempo de armazenamento por 30 dias provocou alteração na resistência da união dos cimentos resinosos RelyX ARC e BisCem. / This study evaluated the push-out bond strength of two self-adhesive resin cements and a conventional etch-and-rinse resin cement on root dentin. Sixty human third molars were endodontically treated and a glass fiber post was cemented with one of three resin cements. Each root was cut transversely to obtain three slices (dentin-post) of 1 mm thick. The slices of the cervical, middle and apical root canal were stored in deionized water at 37 °C for 24 hours or 30 days. After storage, the push-out test was performed. The values of bond strength were evaluated by ANOVA three way and Tuckey’ test (p = 0,05) and the types of fracture were evaluated by scanning electron microscopy. The bond strength of the self-adhesive resin cement RelyX U100 was superior to the RelyX ARC etch-and-rinse cement, after the two storage periods (p > 0.05). The analysis of 24 hours showed that at the cervical third, the values of bond strength of RelyX ARC were higher than that of the middle and apical thirds (p < 0.05). After 30 days of storage, the values at the three root thirds did not differ. The values of RelyX U100, on the three regions of the root canal did not differ, in both evaluations (p > 0.05). After 24 hours, BisCem showed higher bond strength at the apical third, followed by cervical. After 30 days, the values of bond strength at the three root thirds did not differ (p > 0.05). RelyX U100 did not exhibit changes in bond strength values after 30 days of storage (p > 0.05). BisCem showed no differences in the values obtained after 24 hours and 30 days of aging at the cervical and middle thirds (p > 0.05). The storage time of 30 days reduced the values of bond strength at the three root thirds of RelyX ARC. RelyX U100 e BisCem had the highest number of cohesive failures of the zone of interaction. RelyX ARC presented a higher number of cohesive failures of the hybrid layer were observed. It was concluded that the RelyX U100 self-adhesive resin cement showed higher bond strength than the conventional resin cement RelyX ARC, on the three root thirds, in both periods. BisCem showed bond strength comparable to RelyX U100. The storage time for 30 days caused changes on the bond strength of the RelyX ARC and BisCem resin cements.

Le pou rouge Dermanyssus gallinae est un acarien d’importance sanitaire et économique majeure en élevage de poules pondeuses partout dans le monde mais paradoxalement le fonctionnement de son écosystème a été relativement peu étudié. Hématophage strict, D. gallinae n’est pas un parasite typique, il entretient une relation lâche mais obligatoire avec son hôte. Confiné dans l’environnement proche de son hôte (nids, fientes sèches, litière, fumier, . . .) D. gallinae est fortement soumis aux interactions avec les autres organismes qui peuplent ces microhabitats. Ce travail a pour objectif d’apporter des éléments pertinents de caractérisation de cet écosystème singulier mal connu pour, au delà de la production de connaissance, alimenter une réflexion sur le développement de stratégies de gestion intégrée innovantes afin de s’affranchir de la stricte lutte chimique qui reste à l’heure actuelle le moyen de luttele plus largement utilisé. L’étude des interactions chimiques entre le pou rouge et son hôte a permis de mieux identifier les sources de stimulus et mieux comprendre les réponses de D. gallinae aux odeurs de poule ainsi que de déterminer dans quelle mesure il était possible d’interférer entre l’hôte et son microprédateur au moment de l’étape de repérage. La caractérisation de la structure des communautés d’arthropodes partageant les mêmes microhabitats que le pou rouge a montré que D. gallinae côtoyait plusieurs espèces d’acariens et insectes prédateurs d’arthropodes qui sont potentiellement ses ennemis naturels. Il a également été mis en évidence que le bâtiment d’élevage constituait une unité propre en termes de composition et de structure des communautés d’arthropodes. Les différences significatives de fréquence et d’occurrencedes différentes espèces prédatrices entre bâtiments, ainsi que leur capacitéde propagation depuis l’environnement extérieur constituent des indicateurs prometteurs pour le développement de la lutte biologique par conservation contre le pou rouge. Des questions transversales quant aux effets croisés, synergiques ou antagonistes, entre la manipulation des odeurs de l’hôte et la mise à contribution des processus écologiques impliquant les arthropodes non hématophages sont posées en vue d’une démarche intégrant ces outils ainsi que les autres moyens de contrôle disponibles dans un contexte de protection biologique intégrée du pou rouge. / The Poultry Red Mite (PRM) Dermanyssus gallinae is a mite of major sanitary andeconomic importance for the egg production industry worldwide but paradoxicallythe functioning of its ecosystem has been little studied. The objective of this work was to provide relevant elements for the characterization of this singular ecosystem that is poorly known, in order to, beyond the production of knowledge, contribute to the development of innovative strategies of integrated management. This is expected to allow going further than the strict chemical control which is still to date the most widely used means of control. The study of the chemical interactions between the PRM and its host allowed to better identify sources of stimulus and to better understand D. gallinae’s responses to chicken odors as well as to determine to what extent it was possible to interfere between the host and its micropredator during the first phase of the host location. The characterization of the structure of arthropod communities sharing the same microhabitats as does PRM showed that D. gallinae was associated with several species of mites and predatory insects of arthropods which could potentially be its natural enemies. It was also demonstrated that the livestock building was a specific unit in terms of the composition and structure ofthe arthropod communities. Significant differences in the frequency and occurrence of predatory species between buildings and their propagation capacity from the external environment are promising indicators for the development of conservation biological control (CBC) against PRM. A reflection on the possible synergistic and antagonistic cross-effects between the manipulation of host odors and the stimulation of ecological processes involving non-haematophagous arthropods is carried out. This is expected to participate in the development of an approach integrating these tools as well as other available means of control in a context of integrated biological protection of PRM.

Ce travail de recherche est axé sur la compréhension du comportement en flexion, statique et instantané, des structures multimatériaux acier-béton collées du génie civil. La première étape consiste à mener une analyse expérimentale et numérique par éléments finis non linéaire sur la caractérisation de la connexion. L’essai Push-Out a été retenu : deux dallettes de béton C25/30 sont connectées à un profilé métallique. Nous faisons varier la géométrie des dallettes et du joint de colle. La ruine est cohésive dans le béton proche de l’interface par cisaillement. Un effet favorable du frottement entre dallette et presse peut se développer et induire le développement de contraintes de compression et augmenter la contrainte de cisaillement moyenne à l’interface. Les dimensions des éprouvettes et du joint de colle influent sur la charge de ruine. Ainsi, l’essai Push-Out est, dans l’état actuel de connaissances, difficile à utiliser pour la caractérisation de la connexion collée acier-béton en vue du dimensionnement de structures. La seconde partie est consacrée à l’analyse du comportement de poutres mixtes acier béton collées. Un essai sur poutre constituée de prédalles et d’une dalle de compression confirme que le collage est une alternative aux connexions traditionnelles. Nous développons aussi un modèle de calcul en variables généralisées et en variables locales en 3D non linéaire. La modélisation par éléments finis apporte plus de précisions, notamment sur l’état de contraintes à proximité de l’interface et à l’approche de la ruine. Les dimensions du joint de colle et la plastification du profilé influent sur la zone de rupture dans le béton. / This PhD thesis investigates the connection of steel-flexural members by bonding and focuseson static and instantaneous behavior. First, experimental and numerical analyses are performed. A push out test is used : two concrete blocks are connected to steel members. The influence of the concrete blocks and bonding joint geometry is examined. Cohesive shear failure appears in concrete near the interface. Failure can occur when the average shear strain is twice the tension limit of concrete, which can be explained by favorable slipping between the concrete block and the support. In this case, the bonding joint is not only solicited in shear but also in compression. Results depend on the length of bonding joint and concrete blocks geometry. So, push out test cannot be now used to characterize the bonding connection between steel and concrete in order to design structures. The second is about the analysis of the behavior of steel concrete composite beams. A precast beam with compressive concrete was tested. Results show that a bonding connection can be an alternativesolution regardless of the slab manufacturing. We develop two numerical models. The first one is based on multi-layer beam modeling and the second one is a nonlinear 3D finite element model. The stress distribution close to the interface and near failure is more accurate with the finite element model than with the generalized model. Bonding joint geometry and plastification of steel girder have an influence on the failure region in the concrete.

Ce travail porte sur la compréhension du comportement en flexion, statique instantané, en fatigue et en fluage des structures multi matériaux du génie civil, constituées d'acier et de béton et assemblées par un adhésif de type époxy. L'analyse et la résolution du problème posé se feront à deux échelles : au niveau de l'interface et à l'échelle d'un élément de structure. De plus, l'attention sera tout particulièrement portée sur le comportement au cours du temps (fluage, relaxation, retrait…), la fatigue et la durabilité sous différents environnements. La première étape consiste à mener une analyse expérimentale sur la caractérisation de la connexion acier-béton, à l'échelle de l'interface, en vue de repérer les principaux facteurs influençant leur comportement mécanique. Pour cela, L'essai push out, analogue à celui utilisé pour caractériser les connecteurs des ponts mixtes, a été plus particulièrement utilisé. Des essais de vieillissement accéléré par immersion dans un bain d'eau chaude ont été réalisés. Ils n'ont pas diminué la contrainte de cisaillement moyenne à rupture de façon significative mais ont en revanche modifié le mode de ruine qui devient mixte (adhésif et cohésif dans la colle). Cette modification est à la fois due au primaire et à l'adhésif lui-même dont les performances intrinsèques diminuent avec le vieillissement. A l'échelle d'un élément de structure, nous avons enrichi les données expérimentales existantes sur le comportement instantané des poutres mixtes acier-béton collées avec la réalisation de 7 essais de flexion avec deux modes de sollicitation (flexion 3 et 4 points). Ces essais nous donnent une base solide pour nos essais en fatigue et sous fluage. On constate que le mode de ruine est mieux prédit en se basant sur une comparaison entre la contrainte de cisaillement dans les poutres avec les contraintes de cisaillement limite déduites des essais push-out. Cette conclusion montre la pertinence des essais push-out dans l'objectif de les prendre comme critère de dimensionnement. Aussi, et contrairement aux travaux antérieurs, nous pouvons conclure que la contrainte moyenne de cisaillement à l'interface entre le béton et l'acier est supérieure à la résistance en traction du béton utilisé. Pour le comportement à long terme, trois poutres ont été testées sous charge cyclique pour plus de 2 million de cycles et à plusieurs niveaux de charge. Une autre poutre a subi une charge constante pendant 7 mois pour étudier l'influence de fluage sur ce type de structure. Après les essais de fatigue et fluage, le comportement des poutres est analogue à celui des poutres de référence. Nous avons toujours une ruine par rotule plastique et non par cisaillement du joint de colle ce qui confirme sa bonne résistance vis-à-vis ces deux phénomènes / This PhD thesis focuses on understanding the static, fatigue and creep behavior of composite-flexural members made of steel and concrete and assembled by adhesive epoxy. The analysis and resolution of the problem will be carried out at two levels: the interface and the structural element. In addition, attention will be particularly focused on the time-dependent behavior (creep, relaxation, shrinkage ...), fatigue and durability in various environments. The first step is to conduct an experimental analysis on the characterization of the steel-concrete connection in order to identify the main factors influencing their mechanical behavior. To do this, a Push-out test, similar to that used to characterize a steel-concrete element with studs, was especially used. An accelerated aging test, by immersion in a hot water bath, has been made. They have not decreased significantly τu but changed the failure mode which becomes mixed (adhesive and cohesive in the adhesive). This change is due to a decrease of the intrinsic performance of the primary and the adhesive with aging. From a structural point of view, we have improved the existing experimental data on the instantaneous behavior of steel-concrete bonded beams by performing seven beam tests with two modes of loading (3 and 4 point bending test). These tests give us a solid foundation for our fatigue and creep tests. It is found that the failure mode is better predicted based on a comparison between the shear stress in beams with shear limit provided by push-out tests. This finding indicates the relevance of the push-out tests as a design criterion. Also, unlike previous work, we can conclude that the average shear stress at the interface between the concrete and steel is greater than the tensile strength of the concrete used.For the long-term behavior, three beams were tested under cyclic loading for over 2 million cycles with several load levels. Another beam has been test with a constant load for 7 months to investigate the influence of creep on this type of structure. After fatigue and creep tests, the behavior of the beam is similar to that of reference beams. We have always a failure with plastic hinge and not a shear failure which confirms the good resistance of the adhesive joint in case of creep or fatigue

Au cours des dernières années, le développement des cellules organiques à réseaux interpénétrés a permis d’améliorer les rendements de conversion photovoltaïque (PV). Ces dispositifs incorporent une couche active constituée d’un mélange d’un matériau donneur d’électron (D) et d’un matériau accepteur d’électron (A). La réalisation de ces cellules requiert une optimisation minutieuse de ce mélange et de la morphologie de cette couche photo-active qui en résulte. Cette dernière peut cependant évoluer spontanément vers une ségrégation de phase, généralement délétère pour les performances PV. Une solution possible, et relativement peu étudiée, consiste à lier chimiquement le donneur D et l’accepteur A par un espaceur non-conjugué. Les travaux décrits dans ce manuscrit portent sur la synthèse et la caractérisation d’assemblages moléculaires de type D-σ-A ainsi que leur utilisation comme matériau dit « unique » pour la fabrication de cellules solaires organiques mono composant. Une première famille de dyades et triades à base d’un bloc donneur de type quaterthiophène a été étudiée. Cette partie décrit la méthodologie générale d’assemblage des blocs D et A via une réaction de cycloaddition de type Huisgen. Au cours des chapitres suivant, plusieurs dyades basées sur un bloc donneur « push-pull » ont été synthétisées puis caractérisées. Les performances PV de ces composés ont été évaluées au sein de cellules solaires mono-composant et les meilleurs rendements de conversion, atteignant 1.4 %, rivalisent avec l’état de l’art. / Over the last few years, the development of bulk heterojunction organic solar cells (BHJ OSCs) led to significant increase in photovoltaic (PV) efficiency. Such devices are based on interpenetrated networks of an electron-donor material (D) and an electron-acceptor material (A) constituting the active layer. Nevertheless a careful optimization of the morphology is required to reach high power conversion efficiency. Furthermore, this optimized morphology can evolve towards spontaneous phase segregation which can be detrimental for the PV performances. To circumvent these limitations, a relatively unexplored approach relies on the use of a material where the donor and the acceptor moieties are covalently linked to each other through a nonconjugated π-connector. In this context, the work reported herein describes the synthesis and characterization of various molecular D-σ-A assemblies, as well as their preliminary evaluation as “unique” material for the realisation of single component organic solar cells (SC-OSCs). A first family of dyads and triads, based on quaterthiophene moieties as donor block, was studied. A general methodology to assemble the two D and A blocks via a Huisgen-type click-chemistry is described. Then, in the next chapters, several dyads based on a “push-pull” donor block have been synthesized and characterized. The PV performances of these compounds have been evaluated in SC-OSCs leading to power conversion efficiency up to 1.4 %, a value close to the state of the art.

Au cours des dernières décennies, les chromophores organiques “push-pull” ont vu leur intérêt grandir en raison de leurs applications potentielles dans les domaines des transistors à effet de champ, de l'optique non linéaire, des OLEDs, et du photovoltaïque. Dans le cadre de la conception de cellules photovoltaïques, ces structures moléculaires correctement organisées sur une surface devraient permettre d’améliorer l’interface donneur/accepteur, l’absorption optique, et d’augmenter le volume de la couche active. Nous avons développé une synthèse en plusieurs étapes de nouvelles molécules “push-pull” comportant une tête réactive thiol autorisant la formation de monocouches moléculaires auto-assemblées (SAM) sur surfaces d’or ou d’ITO. En variant les groupements donneur, accepteur, et l’espaceur il a été possible de moduler les propriétés optiques et électroniques.Les produits obtenus possèdent une forte absorption de lumière et peuvent donc être efficaces pour le photovoltaïque. Les monocouches moléculaires finales des chromophores avec ou sans nanoparticules d’or ont été étudiées principalement par angles de contact, techniques de spectroscopie IR, UV-Vis, XPS, et par microscopie à sonde locale (STM, AFM). Les matériaux ainsi obtenus à base de SAMs de chromophores “push-pull” et de nanoparticules de métaux nobles ont ensuite caractérisés électriquement et optiquement pour évaluer leur utilisation potentielle pour la conversion de l’énergie photovoltaïque. / During the past decades, the synthesis of organic donor-acceptor (D/A) “push-pull” chromophores has been of considerable interest because of their potential use in nonlinear optics, LEDs, field effect transistors, and photovoltaics (PV). As a part of the design of the PV cells, these molecular structures correctly arranged on a surface should improve the donor/acceptor interface, the optical absorption, and increase the volume of the active layer. We have developed a multi-step synthesis of new “push-pull” molecules bearing a thiol reactive group enabling to form self-assembled monolayers (SAM) on gold or ITO surfaces. Combining various donor, acceptor, and spacer moieties we could tune the “push-pull” optical and electronic properties. The obtained “push-pull” products exhibit a high light absorption and can thus be effective in PV applications. Final SAMs with and without nanoparticles were studied mainly by contact angles, UV-vis, IR and XPS spectroscopy, ellipsometry and near-field microscopy (STM and AFM). As-obtained organic layers were then electrically and optically characterized to assess their potential use in the field of PV energy conversion.

L’interdisciplinarité est désormais inhérente à la recherche scientifique. L’essor des recherches dans le domaine médical a notamment favorisé cette interdisciplinarité. C'est dans ce contexte que s'inscrivent les travaux présentés dans ce manuscrit. En effet, ce dernier vise à la production de nouveaux outils adaptés à des problématiques des sciences de la vie. Ce manuscrit traite de spectroscopie de la fluorescence et de chimie des acides nucléiques. Il est divisé en deux sections : Dans la partie I, nous présentons de nouveaux fluorophores push-pull très brillants, non toxiques et pouvant être utilisé en cultures cellulaires. Ces composés, basés sur des motifs benzothiazoles, peuvent être modulés structurellement afin d'obtenir les propriétés photophysiques souhaitées. D'ailleurs, pour ces composés, une relation structure-propriétés photophysiques a été établie. Ensuite, en utilisant ces fluorophores, nous avons conçu de nouvelles sondes fluorescentes pour suivre l’activité enzymatique de la β-galactosidase. Cette dernière étant un marqueur de la sénéscence cellulaire, nous avons utilisé nos sondes pour détecter la sénescence, in vitro, par des méthodes de microscopie de fluorescence et de cytométrie en flux. La partie II de ce manuscrit est consacrée à la chimie des acides nucléiques. Tout d'abord nous y décrivons la préparation et l'évaluation de nouveaux ligands d’ARN ciblant le domaine IIId de l'IRES du VHC. Ces ligands présentent d'une part, un motif permettant de faire un triplet de base avec la séquence IIId afin d'apporter de la spécificité, et d'autre part, des fonctions aminées afin de stabiliser le triplet par interactions électrostatiques avec les phosphodiesters de IIId. Enfin, la dernière partie concerne le développement d'une nouvelle stratégie permettant la fonctionnalisation post-synthèse d'acides nucléiques en position anomère. Pour ce faire, nous avons conçu des plateformes phosphoramidites qui, une fois incorporées dans des brins oligonucléotidiques, peuvent être impliquées dans diverses réaction de glycosidation. / Interdisciplinary is an obvious feature of scientific research. Notably, the continuously expanding researches in the medical field fostered this interdisciplinarity. Within this context, the work presented here deals with fluorescence spectroscopy and nucleic acid chemistry and aims at providing new tools suited for applications in life sciences. This manuscript presents two sections. In Part I, we developed novel series of highly bright and non-toxic push-pull fluorophores, compatible with cellular applications. In fact, we describe new benzothiazole-based fluorophores that can be structurally modulated to provide dyes with tunable photophysical properties. Their structure-photophysics relationship is also reported. Next, using these fluorophores, we produced new fluorescent probes to monitor the enzymatic activity of the β-galactosidase. Of note, since β-galactosidase is a marker of cellular senescence, we also used our probes for the detection of early stages of cellular senescence using fluorescence microscopy and flow cytometry analysis. Part II of this manuscript is devoted to the chemistry of nucleic acids. First, we describe the preparation and evaluation of novel RNA ligands targeting the IIId domain of the HCV IRES. These ligands can make a base triplet with the IIId sequence to provide specificity, and harbour amino functions to stabilize the triplet by electrostatic interaction with the phosphodiesters of IIId. Finally, the last part concerns the development of a new strategy allowing the post-synthetic functionalization of nucleic acids at the anomeric position. To do this, we designed new phosphoramidite platforms that, once incorporated into oligonucleotide strands, can be involved in various glycosidation reactions.

Doctoral thesis deals with failure detection methods in wireless access network using distributed stochastic algorithms. A new method of detecting a fault based on the push-sum algorithm has been designed and simulated. Within the scope of the work objectives, the statistical credibility of the average push-sum protocol convergence rate representative and the effect of message loss during the calculation on the robustness of the system using this protocol were compared. Based on the acquired knowledge, the ability of the protocol to mathematically derive deviations from the real average of the values in the specified topology was demonstrated and thereby the existence of an abnormality in the network has been proved or refuted.