Made available in DSpace on 2014-06-11T19:29:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-20Bitstream added on 2014-06-13T20:39:31Z : No. of bitstreams: 1 prado_ml_me_arafcl.pdf: 1040279 bytes, checksum: 4a6e98555491503d46d5e919e8f732a8 (MD5) / Novos padrões de gestão da mão-de-obra e da produção têm sido constantes nas usinas de açúcar e álcool da região de Ribeirão Preto, Estado de São Paulo. Decorrentes da modernização que atingiu todo o espectro produtivo do setor e que resultou em sensível diminuição do contingente de trabalhadores, tais padrões se caracterizarão pela implantação de diversas estratégias de envolvimento, configuradas pela realização de treinamentos motivacionais, enriquecimento das tarefas do cargo e, sobretudo, estabelecimento de programas de remuneração por produtividade e resultados operacionais, o que associaria o setor às tendências globais de flexibilização e precarização do trabalho. O presente trabalho é resultado da observação direta dos procedimentos de gestão da mão-de-obra de duas usinas da referida região, que por suas capacidades produtivas e localizações, são significativas para o entendimento dessa nova realidade que se torna cada vez mais ampla no setor. / New standards of labor management and production have been constant in alcohol and sugar mills of Ribeirão Preto Region, São Paulo State. Due to the modernization that reached all the productive spectrum of the section and resulted in sensible decrease of the workers contingent, such standards will characterize themselves for the implantation of many development strategies, such as: motivational training, enrichment of position tasks and, above all, remuneration program associated to productivity and operational results that will associate the section to the global tendencies of flexibility and part-time job. This present work is the result of a right observation of the labor management procedures of two mills located in the region mentioned above, that due to their productivity and locations, are significant for the understanding of this new reality that is becoming wider and wider in this section.

Les Pensées Répétitives Négatives (PRN) font référence à des pensées récurrentes, prolongées et relativement incontrôlables au sujet de nos expériences négatives passées, actuelles ou anticipées. Ce processus transdiagnostique serait impliqué dans de nombreux troubles psychologiques, dont les troubles de l’usage de l’alcool (TUA). Cette thèse s’inscrit dans une démarche processuelle afin d’étudier l’impact des PRN sur la consommation d’alcool chez des patients souffrant d’un TUA. La recension systématique des travaux concernant la relation entre PRN et consommation d’alcool a souligné des interrogations concernant l’influence du sexe et de la symptomatologie anxio-dépressive sur ce lien. Afin de répondre à ces questions laissées sans réponses par la littérature, nous avons menées une étude écologique en temps réel via l’utilisation d’une application électronique qui enregistraient les PRN, les émotions et la consommation d’alcool chez des patients souffrant d’un TUA, suivis en ambulatoire. Pour mener à bien cette étude, deux outils transdiagnostiques d’évaluation des PRN ont d’abord été validés. Le Perseverative Thinking Questionnaire a permis l’évaluation transdiagnostique des PRN-traits, soit la tendance habituelle à utiliser des PRN et le Momentary Ruminative Self-Focus Inventory, a permis d’examiner les PRN-états, soient le recours aux PRN au moment de la passation. Les résultats de la thèse démontrent que les PRN expliquent la consommation d’alcool. Ils sont discutés en lien avec la formulation métacognitive triphasique des problèmes d’alcool. L’intérêt de valider la prise en charge transdiagnostique des PRN dans le cadre des TUA est également développée. / Repetitive Negative Thinking (RNT) refers to a style of recurring, relatively uncontrollable and prolonged thoughts about one’s current, past or anticipated negative experiences. This transdiagnostic mental process is shared across a wide range of psychological disorders, including alcohol use disorders (AUD). The current thesis examined the link between RNT and alcohol use among patients suffering from an AUD in a processual perspective. The systematic review of the literature on the relationship between RNT and alcohol use highlighted some questions about the impact of sex and anxious or depressed symptoms. To address these unanswered questions, we conducted an ecological study in real time through the use of an electronical application assessing RNT, mood and alcohol consumption among AUD patients. To accomplish this aim, two transdiagnostic scales evaluating RNT were validated. The Perseverative Thinking Questionnaire assessed RNT-traits which is the habitual tendency to have RNT, and the Momentary Ruminative Self-Focus Inventory examined RNT-state which is the use of RNT at the time of the assessment. Results of this thesis demonstrated that the link between RNT and alcohol use was direct. They are discussed according to the triphasic metacognitive formulation of problem drinking. The interest of validating the Rumination-focused Cognitive and Behavioural Therapy for AUD patients is developed.Repetitive Negative Thinking (RNT) refers to a style of recurring, relatively uncontrollable and prolonged thoughts about one’s current, past or anticipated negative experiences. This transdiagnostic mental process is shared across a wide range of psychological disorders, including alcohol use disorders (AUD). The current thesis examined the link between RNT and alcohol use among patients suffering from an AUD in a processual perspective. The systematic review of the literature on the relationship between RNT and alcohol use highlighted some questions about the impact of sex and anxious or depressed symptoms. To address these unanswered questions, we conducted an ecological study in real time through the use of an electronical application assessing RNT, mood and alcohol consumption among AUD patients. To accomplish this aim, two transdiagnostic scales evaluating RNT were validated. The Perseverative Thinking Questionnaire assessed RNT-traits which is the habitual tendency to have RNT, and the Momentary Ruminative Self-Focus Inventory examined RNT-state which is the use of RNT at the time of the assessment. Results of this thesis demonstrated that the link between RNT and alcohol use was direct. They are discussed according to the triphasic metacognitive formulation of problem drinking. The interest of validating the Rumination-focused Cognitive and Behavioural Therapy for AUD patients is developed.

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Hospital Universitário Antonio Pedro / Hospital Federal de Ipanema / Hospital Municipal Souza Aguiar / Introdução: Gliomas são tumores cerebrais primários caracterizados pelo crescimento difuso e invasivo. Estudo biomatemático de proliferação e migração dos gliomas propõe que o crescimento de tumores na substância cinzenta profunda cerebral teria um intervalo de tempo maior comparado a lesões situadas na substância branca lobar, onde a invasão e migração seriam mais rápidas. Objetivo: Estabelecer uma correlação da topografia tumoral e edema peritumoral com a resposta terapêutica à administração intranasal do álcool perílico (AP) em pacientes com glioblastoma (GBM) recidivo após tratamento convencional. Métodos: A coorte incluiu o estudo retrospectivo de 119 pacientes com glioma recidivo, sendo 52 em tratamento paliativo de suporte (grupo controle não pareado) e 67 que foram incluídos no Estudo Fase I/II do álcool perílico e receberam administração pela via inalatória de 440 mg de AP diariamente durante o período de Janeiro 2005 a Dezembro 2009. Os parâmetros avaliados incluíram aspectos clínicos e de neuroimagem: topografia tumoral, volume tumoral, presença de desvio da linha média e extensão de edema peritumoral; análise dos dados demográficos, sintomas iniciais e sobrevida global. Análise estatística foi realizada usando testes log rank. A sobrevida global foi determinada pelo método de Kaplan-Meier, incluindo intervalos de confiança de 95%. Resultados: Pacientes do grupo controle apresentaram sobrevida reduzida (p < 0,0001) em relação ao grupo tratado com AP. Dentre os 67 pacientes com GBM, 14 (21%) apresentavam localização talâmica e 53 (79%) localização lobar. Pacientes com tumor localizado na região do tálamo sobreviveram significativamente mais tempo do que aqueles com tumor localizado na região lobar (log rank test, p = 0,0003). Pacientes que apresentaram regressão tumoral acompanhada de redução do edema peritumoral apresentaram resposta clínica positiva, enquanto aqueles com regressão tumoral sem redução do edema peritumoral apresentaram evolução clínica desfavorável, independentemente da topografia tumoral. Presença de desvio da linha média (> 1 cm) foi estatisticamente significante como fator de risco para menor sobrevida (log rank test, p = 0,0062). Conclusões: Este estudo sugere que: (1) pacientes com tumor localizado na região profunda (tálamo) apresentaram sobrevida média maior do que pacientes com tumor localizado na região lobar; (2) edema peritumoral foi um fator determinante na sintomatologia, provavelmente implicado na morbidade podendo estar relacionado com a característica de invasividade do glioma maligno. Esses achados apóiam a teoria de que fatores presentes em diferentes microambientes do tecido cerebral (tálamo, córtex) possam contribuir para o processo de progressão tumoral, para o prognóstico clínico e a resposta terapêutica ao álcool perílico administrado pela vias inalatória / Introduction: Gliomas are primary brain tumors are characterized by diffuse and invasive growth. Study biomathematical proliferation and migration of gliomas suggests that the growth of tumors in deep brain gray matter would have a longer time interval compared with lesions in the lobar white matter, where the invasion and migration would be faster. Objective: To establish a correlation of peritumoral edema and tumor topography with the therapeutic response to intranasal administration of perillyl alcohol (PA) in patients with glioblastoma (GBM) relapsing after conventional treatment. Methods: The cohort included a retrospective study of 119 patients with relapsing glioma, 52 palliative care support (control group) and 67 that were included in the Study Phase I / II and received perillyl alcohol administration by inhalation of 440 mg AP daily during the period January 2005 to December 2009. The parameters evaluated included clinical and neuroimaging: topography tumor, tumor volume, presence of midline shift and extent of peritumoral edema, analysis of demographic data, initial symptoms and overall survival. Statistical analysis was performed using log rank tests. Overall survival was determined by Kaplan-Meier, including 95% confidence intervals. Glioma is a primary brain tumor characterized by diffuse growth and invasiveness. The pattern of differential tumor growth and invasiveness suggest that patients with tumoral lesion located in the lobar white matter region present lower survival rate than patients with lesion located in deep brain gray matter (thalamo). Objective: To establish a correlation between tumor topography and peritumoral edema with the therapeutic response to intranasal administration of perillyl alcohol (POH). Methods: This retrospective study analyzed 119 patients with recurrent glioma being 52 under supportive treatment (control group) and 67 included in the Phase I/II clinical trial that received intranasal administration of 440 mg daily AP from January 2005 to December 2009. The following parameters were analyzed: clinical assessment; demographic data, symptoms and overall survival, neuroimage analysis of topography including tumor volume, midline shift and extent of peritumoral edema. Statistical analysis was performed using log rank tests. The overall survival was determined by the Kaplan-Meier method, including 95% confidence intervals. Results: Patients from control group showed reduced overall survival (p < 0,0001) in comparison with patients included in the Phase I/II that received treatment with perillyl alcohol. Among 67 GBM patients, 14 (21%) had tumoral lesion in the thalamic region and 53 (79%) in the lobar region. Patients with thalamic tumor survived significantly longer than those with tumor located in the lobar region (log rank test, p = 0.0003). Patients with tumor regression with reduction of peritumoral edema had positive clinical response, whereas poor prognosis was observed in those with tumor regression but without reduction of peritumoral edema. Presence of midline shift (> 1 cm) was statistically significant as a risk factor for shorter survival (log rank test, p = 0062). Conclusions: This study indicates that: 1) patients with tumoral lesion in the deep region (thalamic) have longer overall survival than GBM patients with tumors in the lobar region; 2) presence of peritumoral edema contributes strongly to symptoms and is likely to influence morbidity and the invading potential of malignant glioma. These findings support the hypothesis that interaction between glioma cells and different brain microenvironment (thalamo, cortex) can influence the process of glioma progression, clinical prognosis and therapeutic response to intranasal delivery perillyl alcohol

Orientadores: Antonio José Gomez Cobo, César Augusto Moraes de Abreu / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T13:01:21Z (GMT). No. of bitstreams: 1 Freire_EleonoraMariaPereiradeLuna_D.pdf: 2485469 bytes, checksum: 5c15bdbbb73bd51d623eb4811e9d2248 (MD5) Previous issue date: 2005 / Resumo: Os catalisadores à base de paládio apresentam particular interesse para o tratamento de gases de exaustão automotiva, notadamente no caso da combustão do etanol. O presente trabalho tem o objetivo de estudar as propriedades físico- químicas de catalisadores Pd - Fe e Pd - Co suportados em alumina modificada pelo óxido de cério. Para tanto, catalisadores modelo foram preparados através do método de impregnação por via úmida, empregando-se sais precursores à base de nitrato dos metais, e os suportes Al2O3, CeO2 e CeO2/Al2O3. Os catalisadores obtidos tiveram seus teores metálicos determinados por meio de espectrofotometria de absorção atômica, tendo sido caracterizados através de adsorção de nitrogênio (método B.E.T), espectroscopia no infravermelho, difração de raio-X, redução à temperatura programada. Os sistemas preparados foram avaliados pela reação catalítica de oxidação do etanol em fase gasosa em um microreator tubular de leito fixo, operando a pressão atmosférica e a temperatura de 3500 C. Os catalisadores preparados apresentam frações mássicas em torno de 2 % para o Pd, e de 1% para os aditivos Fe ou Co. A adição de Pd, Pd-Fe e Pd-Co aos suportes Al2O3 e CeO2/Al2O3 não levou a modificações, nos volumes dos poros e nas áreas superficiais específicas. Esses resultados mostram que a adição dos metais pouco influenciam nas características texturais. Enquanto para os bimetálicos suportados em céria, há a hipótese da existência de microporos apesar de ter ocorrido diminuições relativas das áreas superficiais específicas os volumes dos poros permanecem constantes. Na reação de oxidação do etanol, os resultados das análises cromatográficas levam a concluir que a introdução dos aditivos cobalto e ferro ao paládio provoca redução de eficiência na conversão do etanol para os sistemas CeO2 e CeO2/Al2O3. A adição do cobalto ao paládio na alumina aumenta a conversão e apresenta alto rendimento para a oxidação do etanol e o catalisador paládio suportado em céria apresenta conversão menor do que o Pd-Co sobre alumina porém rendimentos semelhantes / Abstract: Palladium based catalysts have been, applied at the treatment of the automotive gas exhaustion, particularly in the case of ethanol combustion. In this context, the actual work has the aim to study the physical and chemical properties of the Pd, Pd-Fe and Pd-Co catalysts supported in alumina, ceria and alumina modified by the cerium oxide. The wet impregnation method was used to develop the model catalysts. Precursor salts metal nitrates as well as the supports Al2O3, CeO2 and CeO2/Al2O3, were used for this purpose. The catalysts were characterised by the methods of BET-N2, infrared spectroscopy (I.R), X- ray diffraction (XRD) and reduction at programmed temperature (TPR). The contents of the metal impregnated in the catalysts was quantified by atomic absorption spectrophotometry (A.A.S.). A fixed-bed tubular microreactor was used to evaluate the performance of the catalysts in the oxidation of ethanol in gas phase, at the atmospheric pressure and temperature of 350o C. The mass fractions observed for the palladium catalysts and those that had Fe and Co as additive, were around 2% and 1%, respectively. The addition of the Pd, Pd-Fe and Pd-Co to the alumina support and alumina modified by cerium oxide does not prove modification into they capacity of the porous and surface areas. This results prove that the addition of metals has no power to the textural characteristics. Whereas the supported bimetallic system in ceria has the theory of the existence of micropores despite of a relative decrease of specific surface areas, the capacity of porous remains stable. The ethanol oxidation reaction, and the results of the cromatographicas analysis conclude that the introduction of cobalt and iron into the palladium decreases the efficacy of ethanol conversion into the CeO2 and CeO2/Al2O3 systems. The addition of cobalt into the palladium in alumina increases the conversion and introduces high performance for the ethanol oxidation and the palladium catalyst supported by cerium shows minor , conversion than to the cobalt-palladium upom alumina, but with the same results / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Orientador: Caio Glauco Sanchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica. / Made available in DSpace on 2018-08-05T06:34:56Z (GMT). No. of bitstreams: 1 Almeida_AlexandreAmaralde_M.pdf: 1803116 bytes, checksum: 09df9f4fd3968f1e76a55f1642fcfa37 (MD5) Previous issue date: 2005 / Resumo: Os motores de combustão interna têm sido a principal fonte geradora de trabalho mecânico, especialmente em veículos automotores e sua quantidade tem se expandido de forma exponencial desde sua invenção, no século XIX. Os efeitos deste crescimento podem ser observados pelo aumento do consumo mundial de petróleo e da concentração de gases tóxicos na atmosfera, principalmente nas grandes cidades. Por este motivo, foi desenvolvido o presente trabalho, que tem por objetivo quantificar as melhorias no desempenho e economia de combustível obtidas em um motor automobilístico através do uso de um sistema de ignição dupla. Os ensaios foram realizados usando um motor VW refrigerado a ar e com dupla carburação (1.6 l de cilindrada e taxa de compressão 7,2:1) alimentado com álcool etílico hidratado. Foram feitas análises comparativas com ensaios em plena carga e em cargas parciais (0,8 e 0,9 atm de pressão absoluta no coletor de admissão) a 2000, 3000 and 4000 rpm de forma a evidenciar as vantagens e desvantagens do sistema com ignição dupla. O sistema de ignição dupla foi projetado de modo que as centelhas nas duas velas de cada cilindro ocorressem simultaneamente e que fosse possível o controle dos tempos de ignição. Os resultados obtidos indicam uma melhoria no desempenho para todas as condições de operação, com regimes de carga parcial em que os ganhos superaram os 20% em torque e potência e 15% no consumo específico de combustível / Abstract: Internal combustion engines have been the major source of mechanical work, especially in automotive vehicles, and their amount has expanded exponentially since their invention, in the 19th century. The effects of this growth can be observed in the increasing world petrol demand and concentration of toxic gases in the atmosphere, especially in major cities. For this reason, the present work was developed with the objective to quantify the performance and the specific fuel consumption improvement of an automotive engine operating with a dual ignition system. The tests were made using an air-cooled VW engine with two carburetors (1.6 l displacement and with a 7.2:1 compression ratio) using hidrated ethanol. Comparative analysis were made with data gathered in the tests at WOT (wide open throttle) and partial loads (admission pressures of 0,8 and 0,9 atm) at 2000, 3000 and 4000 rpm in order to evidence advantages and disadvantages of the dual ignition system. The ignition system was designed to generate two simultaneous sparks in each cylinder allowing its timing control. The results indicate a trend of improvement in the performance for all the conditions tested, with profits that surpassed 20% in torque and power and 15% in the specific fuel consumption in partial load operation conditions / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica

Le remplacement des tissus mous du système ostéo-articulaire par des implants synthétiques en hydrogels est souvent limité par un faible ancrage avec le tissu osseux. Une approche pour renforcer l’interface os/implant consiste à fonctionnaliser la surface de l’implant par un revêtement biocéramiques. Dans cette thèse, nous étudions deux approches pour revêtir des hydrogels d’alcool polyvinylique (APV) avec des particules biocéramiques d’hydroxyapatite (HA). Dans une première approche, basée sur le procédé d’enduction, des substrats d’hydrogel ont été revêtus par des particules d’HA enchâssées dans une matrice d’hydrogel d’APV non-dégradable. Dans ce procédé, le contrôle de la composition de la solution de trempage permet d’ajuster finement l’épaisseur, la cohésion et l’adhérence du revêtement, ainsi que le taux d’exposition d’HA à la surface du revêtement. La biocompatibilité avec la pratique chirurgicale et l’ostéointégration de ces revêtements ont été évaluées par une étude in vivo sur un modèle de cicatrisation de tunnel osseux chez le lapin. Ces premiers travaux nous ont menés à la découverte d’une nouvelle approche pour gélifier des films d’hydrogel par un procédé auto-entretenu, qui consiste à utiliser la déplétion de solvant créée à la surface d’un substrat gonflant dans une solution de polymère pour induire la gélification sans action extérieure. Dans ce procédé, la croissance de ces films dépend de la concentration de la solution, du temps de trempage et de la cinétique de gonflement du substrat. Le caractère doux de ce procédé de gélification a été vérifié en encapsulant des fibroblastes, qui restent viables durant 48h. Avec un second procédé plus énergétique, des substrats d’hydrogels d’APV ont été revêtus de couches denses de particules d’HA submicroniques par cold spray. Les paramètres de projection (température, pression, distance de projection) ont été variés systématiquement pour déterminer des conditions de projection appropriées. Un schéma de formation du revêtement est proposé, basé sur les observations microscopiques. Chacun de ces procédés et leur combinaison ouvrent de nouvelles voies dans la conception de système hydrogel-céramique ayant des propriétés microstructurales, mécaniques et biologique contrôlées. / The replacement of soft osteoarticular tissues by synthetic hydrogel implants is often limited by a weak anchorage to bone tissues. One approach to strengthen the bone-implant interface consists in functionalizing the surface of the implant by a coating of bioceramics. In this thesis, we investigate two approaches to coat hydrogels of poly(vinyl alcohol) (PVA) with ceramic particles of hydroxyapatite (HA). In a first “soft” process, based on dip-coating, hydrogel substrates were coated with hydroxyapatite particles embedded in a non-degradable PVA hydrogel matrix. In this process, the control of the soaking solution composition allows to finely tune the thickness, the cohesion and the adhesion of the coating, as well as the HA exposure at the coating surface. The biocompatibility with surgical handling and the osteointegration of these systems were assessed by an in vivo study in a rabbit model of bone tunnel healing. This first approach led to the discovery of a new approach to grow physical hydrogel films by a self-sustained process, consisting in using the solvent depletion created at the surface of a swelling polymer substrate immersed in a PVA solution to induce the gelation of hydrogel films without external action. In this process, the growth of these hydrogel films depends on the solution concentration, the soaking time and the swelling kinetics of the substrate. We verified the gentle character of this process by encapsulating fibroblasts, which remain viable for 48h. In a second more “energetic” process, dense coatings of submicronic HA particles were produced on PVA hydrogel by cold spray. Spraying parameters (temperature, pressure and stand-off distance) were varied systematically to determine efficient spraying condition. Based on microscopic observations, a picture explaining the formation of the coating is proposed. Both processes and their combination open new routes for the design of ceramic-hydrogel systems having controlled microstructural, mechanical and biological properties.

La cellule de Purkinje constitue la seule sortie du cortex cérébelleux. En étudiant les caractéristiques de sa décharge spontanée sur l’animal éveillé, nous pouvons avoir un aperçu de l’intégration par le cortex cérébelleux de ses deux entrées excitatrices, les fibres moussues et les fibres grimpantes. Les souris transgéniques constituent une opportunité réelle de mieux comprendre le fonctionnement et les dysfonctionnements du cortex cérébelleux. Dans ce travail, nous décrivons la décharge spontanée des cellules de Purkinje chez l’animal normal et dans différents modèles de souris ataxiques. Nous avons ainsi mis en évidence différents patterns d’activité correspondant à différents degrés d’ataxie. Ainsi, sur les souris consommant chroniquement de l’éthanol et sur les souris SCA1, qui présentent un très léger trouble de la coordination motrice, nous avons trouvé une fréquence de décharge diminuée des spikes simples et des spikes complexes, sans augmentation de la rythmicité ni émergence d’oscillation du potentiel de champ de local. Les souris déficientes en calbindine, en calrétinine, en parvalbumine, en Ube 3A maternelle, ou ayant subi in utero un syndrome d’alcoolisme fœtal présentent un trouble de la coordination plus net, mais nécessitant toujours des tests adaptés pour être mis en évidence. Ces souris présentent une oscillation rapide soutenue par la décharge rythmique et synchrone des cellules de Purkinje. Cette oscillation est synchronisée dans l’axe des fibres parallèles, et est inhibée par les inhibiteurs des gap junctions, des récepteurs GABAA et NMDA. Par contre, les souris BK-/- dont l’ataxie est évidente même en conditions standards, présentent une oscillation lente synchronisée dans les axes sagittal et frontal, en phase avec les bursts des cellules de Purkinje et avec la décharge des cellules de Golgi. L’existence de ces différents patterns qui regroupent des conditions physiopathologiques qui n’ont pas d’autre point commun qu’un même niveau de déficit de la coordination motrice suggère que les troubles cérébelleux puissent être classifiés en un nombre limité de catégories permettant ainsi une approche thérapeutique plus ciblée. / Doctorat en sciences biomédicales / info:eu-repo/semantics/nonPublished

Dans ce travail, nous nous sommes intéressés au développement d’un nouveau biocapteur enzymatique ultrasensible pour la détection conductimétrique d’une mycotoxine, l’ochratoxine A (OTA). Une peptidase, la thermolysine (TLN), a été choisie comme élément de reconnaissance. Le biocapteur proposé est basé sur l’immobilisation de la TLN dans une matrice d’alcool polyvinylique (PVA)/polyéthylènimine (PEI) contenant des nanoparticules d’or et réticulée à la surface de microélectrodes interdigitées à l’aide de vapeurs de glutaraldéhyde. Dans les conditions optimales (35 min de réticulation, mesure à pH 7 et 25°C), la réponse du biocapteur est linéaire jusqu’à 60 nM et la limite de détection est de 1 nM. Cette valeur est 700 fois plus basse que celle obtenue en utilisant une méthode d’immobilisation basée sur la co-réticulation de la TLN en présence d’albumine de sérum bovin (BSA). La matrice PVA/PEI crée un environnement aqueux favorable à l’enzyme. Par ailleurs, les interactions entre les groupements amines protonés du PEI et les charges négatives des nanoparticules citratées et de la TLN améliore leur dispersion dans la matrice et favorise la stabilisation de l’enzyme et son accessibilité au substrat (OTA). Le biocapteur conductimétrique développé est très reproductible et stable pendant 30 jours lorsqu’il est stocké à 4°C dans du tampon phosphate 20 mM pH7 entre 2 mesures. Le biocapteur a ensuite été évalué sur des échantillons d’huile d’olive commerciale dopée. Aucun prétraitement de l’échantillon n’a été nécessaire et des taux de recouvrement proches de 100% ont été obtenus, démontrant l’absence d’effet de matrice / A new ultrasensitive enzymatic biosensor for the direct conductometric detection of ochratoxin A (OTA) has been developed in this work. Thermolysin (TLN), a peptidase, was chosen as recognition element. The proposed biosensor is based on TLN immobilization into a polyvinyl alcohol (PVA)/polyethylenimine (PEI) matrix containing gold nanoparticles (AuNPs) and cross-linked at the surface of gold interdigitated microelectrodes using glutaraldehyde vapor. Under optimal conditions (35 min cross-linking time, working pH of 7 and temperature of 25◦C), the biosensor response was linear up to 60 nM OTA and the limit of detection was 1 nM. This value was 700 times lower than the detection limit obtained using the more classical method based on enzyme cross-linking in the presence of bovine serum albumin (BSA). PVA/PEI hydrogel creates a very favorable aqueous environment for the enzyme. In addition, interactions between protonated amino groups of PEI and negative charges of both citrated AuNPs and thermolysin improve their dispersion in the polymer blend, favoring enzyme stabilization and accessibility to the substrate (OTA). The developed OTA biosensor was very reproducible and stable over a 30 days period when stored at 4◦C in 20 mM phosphate buffer between two measurements. The method was further evaluated using commercial doped olive oil samples. No pretreatment of the sample was needed for testing and no matrix effect was observed. Recovery values were close to 100%, demonstrating the suitability of the proposed method for OTA screening in olive oil

Cette thèse porte sur la forte alcoolisation ponctuelle des étudiantes irlandaises. Il s’agit en premier lieu de comprendre la progression récente de cette pratique en l’envisageant à partir d’échelles différentes : une perspective à la fois « macro » et comparative à l’aide d’une revue de littérature et une autre « micro », grâce à une recherche empirique qualitative. Celle-ci a été menée à partir de 40 entretiens individuels semi-directifs avec des étudiantes d’un même établissement. L’analyse de leurs perceptions quant à leurs pratiques, leurs prises de risque associées, leurs motivations et des facteurs socio-culturels facilitera l’élaboration de futurs programmes de prévention. Une philosophie de recherche de type écologique a été adoptée, suivant le principe que seule une approche multidisciplinaire permettrait une compréhension globale de ce fait social. Parmi les principaux résultats, nous retenons que la majorité des participantes irlandaises pratiquent le « binge drinking » de façon hebdomadaire. Ceci constitue un obstacle à leur socialisation avec celles d’origine étrangère qui, elles, ne s’y adonnent pas. Le « boire irlandais », en tant que revendication identitaire nationale, s’est en fait utilisé que comme prétexte par des étudiantes qui souhaitent avant tout reculer les échéances de la vie adulte en se cantonnant dans une « post-adolescence ». De plus, cette forme d’alcoolisation correspond moins à une quête d’égalité avec les garçons qu’à un désir de faciliter les rapports de séduction. Enfin, en buvant ainsi, elles cherchent davantage à s’affirmer comme jeunes que comme femmes ou Irlandaises. / This thesis focuses on the heavy episodic alcohol consumption of Irish female students. Firstly, it aims to understand the recent increase of this type of drinking by considering it from different perspectives. A macro and comparative analysis was provided by the literature review as well as a micro one through a qualitative research. Semi-guided individual interviews of 40 female students from the same third-level educational establishment were conducted. A research philosophy of an ecological nature was selected, following the principle that only a multi-disciplinary approach could provide an overall understanding of such a social fact. The key findings reveal that the majority of participants “binge drink » on average twice weekly. This represents an obstacle to their socialisation with female students from foreign origins, who tend not to drink heavily when they socialise. The “Irish drinking”, as a celebration of a national identity, is being used by many participants as an excuse. They try, in fact, to postpone as long as possible, adult roles and responsibilities by shutting themselves away in a “post-adolescence” period. Furthermore, for them, this type of alcohol consumption signifies less a search for equality with their male counterparts than a desire to interact with and seduce them. Finally, by drinking this way, they attempt to affirm themselves as youth rather than as women or Irish.

Le travail de recherche présenté dans cette thèse s’est orienté vers l’élaboration de matériaux avancés et la conception de polymères/composites biosourcés. Ce dernier sujet a été entrepris à travers la combinaison de différentes matières premières biosourcées qui sont connues comme ayant un grand potentiel de substitution des monomères pétrosourcés. Tout d’abord, un travail fondamental a été exécuté en combinant l’huile de lin epoxydée (ELO) avec des dérivés d’anhydrides d’acides comme agents de réticulation, afin de relier la réactivité chimique de polymérisation à la structure du réseau formé et aux propriétés thermomécaniques. Afin de devenir économiquement viable, les bio-raffineries doivent urgemment valoriser les sous-produits issus de la conversion de la biomasse. Fort de ce constat, une deuxième étude sur l’incorporation et la copolymérisation d’une quantité importante d’humins (résidu hétérogène obtenu durant la conversion des sucres en hydroxymethylfurfural (HMF)) avec de l’alcool furfurylique (FA) a été réalisée avec succès afin de créer de nouvelles résines thermodures. Une autre voie proposée consiste en la combinaison de ELO et de FA à travers une polymérisation cationique, dans l’idée de créer de nouvelles résines totalement biosourcées, générant ainsi une gamme de matériaux aux propriétés mécaniques modulables. / The research work presented in this thesis was oriented on advanced thermoset materials and also on the conception of bio-based polymers and composites. This last topic has been investigated by the combination of different bio-based raw materials which are well-known to have a great potential to substitute the petroleum monomers. Firstly, a fundamental work has been done on the combination of epoxidized linseed oil (ELO) and anhydrides as cross-linkers, which links the polymerization reactivity with the network structure and thermomechanical properties. For being economically realistic, the bio-refineries are urged to valorize the sidestream products issued from biomass conversion. In that respect, a second study investigated successfully the incorporation and copolymerization of an important amount of humins (heterogeneous residues obtained during the sugar conversion into hydroxymethylfurfural (HMF)) with furfuryl alcohol (FA) in order to create new resins. Another proposed combination, focused on ELO and FA cationic copolymerization with the purpose to create new fully bio-based resins with tailored mechanical properties. Concerning the elaboration of advanced polymers and composites, a reflection around the hierarchically organized natural materials has been achieved in order to adapt the self-organization and structuration concepts to polymeric network.