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Monitoração in vivo - análise de incertezas / In vivo monitoring analysis of uncertaintiesLucas Rodrigues dos Santos 10 April 2012 (has links)
Este trabalho teve como objetivos estabelecer os protocolos para o cálculo de incertezas de medição e a interpretação dos resultados de monitoração do Laboratório de Monitoração In Vivo (LMIV). Especificamente, o trabalho visou quantificar a contribuição dos fatores de influência para o cálculo de incertezas, e estabelecer a incerteza nas medidas. Foram utilizados dois detectores cintiladores de iodeto de sódio ativados com tálio (NaI:Tl) que possuem dimensões de 8x4\" (detector de corpo inteiro) e 3x3\" (detector de tireóide), um analisador multicanal EG&G Ortec, modelo 920E, e um microcomputador onde os espectros são adquiridos, analisados e armazenados com o auxílio do programa Renascence32, Ortec. As medições foram realizadas utilizando-se o objeto simulador antropomórfico do Alderson Research Labs. O radionuclídeo de interesse adotado para este estudo foi o 137Cs. Foram estudadas as influências dos fatores operador, geometria de medição, condições ambientais, flutuações eletrônicas com o tempo e baixa atividade. A análise das incertezas resultou em uma incerteza combinada relativa de 15,7% para o sistema 8x4\" e 9,8% para o sistema 3x3\". Estes valores foram obtidos seguindo os princípios recomendados no Guia para Expressão da Incerteza de Medição (GUM) da Joint Committee for Guides in Metrology (JCGM). / This work aimed to quantify the contribution of influence factors for the calculation of uncertainties and establish the uncertainties in the measurements of the In Vivo Monitoring Laboratory (LMIV). The materials used were used: two scintillator detectors of sodium iodine activated with thallium (NaI:Tl), with the dimension of 8x4\" (whole body detector) and 3x3\" (thyroid detector), an EG&G Ortec, model 920E multichannel analyzer and a microcomputer, where the spectra are acquired, analyzed and stored, with the support of Ortecs software, Renascence32. The measurements were carried out using the anthropomorphic simulating object from Alderson Research Labs. The targeted radionuclide adopted for this study was 137Cs. The influence factors were operator, measurement geometry, environmental conditions and Electronic fluctuations over time. The analysis of the uncertainties resulted in a relative combined uncertainty of 15.7% for the 8x4\" system and 9.8% for the 3x3\" system. These values were obtained following the Guide for Expression of Uncertainty in the Measurement, (GUM) of Joint Committee for Guides in Metrology (JCGM).
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Cinevivo / CinevivoAlexandre da Silva Carvalho 18 October 2010 (has links)
Esta dissertação tem como objetivo o relato das apresentações de Fluidos, o primeiro projeto realizado no formato CineVivo. Trata-se de uma experiência inédita de longa-metragem realizado ao vivo, com captação, edição e exibição simultâneas. Em diversas locações, atores encenam a história de ficção captada por três câmeras. Essas imagens são transmitidas para a edição em tempo real e a exibição para os espectadores na sala de cinema. As apresentações aconteceram no Centro Cultural São Paulo, no Sesc Pompeia e no CineSESC entre o período de maio de 2009 a maio de 2010. Em anexo, encontram-se o último tratamento do roteiro, o DVD com a versão apresentada no CineSESC e as principais reportagens publicadas na mídia. / The aim of this dissertation is to report the exhibitions of Fluids. This is the first project completed in the format CineVivo. It is a new experience for feature film performed live, with capture, editing and projection simultaneously. At several locations, cast acts the story captured by three cameras that transmit live for realtime editing and projection in the theater. The film was screened at Centro Cultural São Paulo, SESC Pompeia and CineSESC, between May 2009 to May 2010. Attached the last screenplays treatment, DVD with the version presented in CineSESC, and main reports in the media.
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Mitigating the greenhouse gas balance of ruminant production by identifying plants with high tannin concentration and quantifying the methane emission in vivo / Mitigando o equilíbrio de gases do efeito estufa na produção de ruminantes pela identificação de plantas com concentração elevada de tanino e quantificação das emissões de metano in vivoDinesh Kumar Dhanasekaran 19 May 2016 (has links)
In Brazil, with the continued expansion of agriculture for supplying demands from international markets, progressive increases in emissions of green house gases are expected. The purpose of the project was hypothesized with three major approaches, 1) Strategies to mitigate methane emission in small ruminant production systems; 2) Identify tropical plants and individual bioactive compound against methanogenic propertie and 3) In vivo evaluation of the nutrients metabolism of Santa Ines sheep fed with tropical plants. For this, we have performed three experiments. The first study (Expt. 1) was designed to determine the in vitro effects of three tropical tannin rich plants such as Leucaena leucocephala (LL), Mimosa caesalpineafolia (MC), Schinus molle (SM) and one non-tannin rich plant Medicavo sativa (MS) for their anti-methanogenic properties when used with and without polyethylene glycol (PEG). All plants had significantly (P<0.05) influenced the degraded organic matter (TDOM) and degraded neutral detergent fiber (DNDF), especially LL, which had most influence on these parameters compared to other tannin containing plants. LL had positive response on antimethanogenic effects; its nutrient degradability was higher than that of other tannin containing plants. The second study (Expt. 2) was set to evaluate the effect of different organic extracts from the whole plant methanolic extract (MHE) of LL on in vitro gas production and to characterize the chemical constituents by using gas chromatography coupled with mass spectroscopy (GC-MS). Major abundant compounds present at the relative percentages of MHE were found to be stigmasterol trimethyl ester (TMS), neophytadiene, palmitic acid TMS, ?-Linolenic acid TMS and 2, 3, 5, 6-Tetra-M-Anisylbenzene. The effects of additions of different extracts in terms of nutrient degradability (TDOM and DNDF) were increased by all extracts. This study explained that the hexane extract from whole plant MHE was effective against methanogenic activity. The objective of the third study (Expt. 3) was to study the effect of LL plant leaves on rumen fermentation, apparent nutrient digestibility, nitrogen balance and methane production in Santa Ines sheep. The animals were divided in three groups in which they were fed with (i) 88% Tifton 85-hay (Cynodon dactylon) and 12% soyabean meal (Control group, n=4); (ii) 28% Tifton 85-hay (Cynodon dactylon) and 72% LL plus 20 ml solution containing 10g/day/animal of PEG (With PEG group - WPEG, n=6); (iii) 28% Tifton 85-hay (Cynodon dactylon) and 72% LL plus 20 ml of distilled water (Without PEG group- WOPEG, n=6). Nutrient intake (dry matter, organic matter, acid detergent fiber, lignin and crude protein) were higher in WPEG and WOPEG compared to the control group, except neutral detergent fiber intake. Apparent digestibilities and nitrogen metabolism had non-significant effects between the treatments. However, CH4 emissions were significantly lower in WPEG and WOPEG than the control. Furthermore, expressions of microbial populations of methanogens in WPEG had lower tendency than that of WOPEG and control. The most salient findings of this study were that, using plant rich in tannin in diets of small ruminants, we can get more benefits in terms of replacing the source of protein in the diet (food safety) and reduced production of enteric CH4 (animal production) / No Brasil, com expansão da agricultura para suprir as exigências dos mercados internacionais, são esperados aumentos progressivos nas emissões de gases do efeito estufa. O objetivo do projeto foi hipotetisado com três abordagens principais, 1) estratégias para mitigar emissões de metano em sistemas de produção de pequenos ruminantes; 2) identificar plantas tropicais com compostos bioativos com propriedades anti metanogénicas e 3) avaliação in vivo do metabolismo de nutrientes em ovelhas Santa Inês alimentadas com planta taninífera. Para isso, foram efetuados três experimentos. O primeiro estudo (Expt 1) foi concebido para estudar os efeitos in vitro de plantas tropicais ricas em tanino como Leucaena leucocephala (LL), Mimosa caesalpineafolia (MC) e Schinus molle (SM) e uma planta não taninífera, Medicavo sativa (MS) quanto às propriedades anti-metanogénicas quando usadas com e sem polietileno glicol (PEG). Todas as plantas significativamente (P < 0.05) influenciaram na matéria orgânica degradada (MOD) e na fibra em detergente neutro degradada (FDND), especialmente a LL, que teve maior influência sobre estes parâmetros, em comparação com as outras plantas que contém tanino LL teve resposta positiva sobre os efeitos de antimethanogênicos e a degradabilidade dos nutrientes foi maior do que a das outras plantas que contém tanino. O segundo estudo (Expt 2) foi definido para avaliar o efeito de diferentes extratos orgânicos a partir do extrato metanólico da planta (EMP) de LL na produção de gás in vitro e caracterizar os constituintes químicos usando cromatografia gasosa acoplada com espectroscopia de massa (GC-MS). Os compostos mais abundantemente encontrados, em termos de percentagens relativas do EMP, foram o éster de trimetil estigmasterol, neofitadina, ácido palmítico, ácido ?-linolênico e 2, 3, 5, 6-Tetra-M-anizil -benzeno. Os efeitos de adições dos diferentes extratos orgânicos, em termos de degradabilidade de nutriente (MOD e NDFD) foram aumentados para todos os extratos. Este estudo explicou que o extrato de hexano a partir do EMP foi eficaz na atividade anti metanogênicas em modificar a degradação ruminal de nutrientes. O objetivo do terceiro estudo (Expt 3) foi estudar o efeito das folhas da planta LL na fermentação ruminal, digestibilidade aparente de nutrientes, balanço de nitrogênio e produção de metano em ovinos Santa Inês. Os animais foram divididos em três grupos em que eles foram alimentados com (i) 88% feno de Tifton-85 (Cynodon dactylon) e 12% de farelo de soja (Grupo controle, n = 4); (ii) 28% feno de Tifton-85 (Cynodon dactylon) e 72% LL mais 20 ml solução contendo 10g/dia/animal de PEG (grupo com PEG - CPEG, n = 6); (iii) 28% feno de Tifton-85 (Cynodon dactylon) e 72% LL mais 20 ml de água destilada (sem PEG-grupo-SPEG, n = 6). A ingestão de nutrientes (matéria seca, matéria orgânica, fibra em detergente ácido, lignina e proteína bruta) foram maiores no grupos CPEG e SPEG em relação ao grupo controle, exceto a ingestão de fibra em detergente neutro. As digestibilidades aparentes e o metabolismo do nitrogênio não apresentaram efeitos significativos entre os tratamentos. No entanto, as emissões de CH4 foram significativamente inferiores nos grupos CPEG e SPEG em comparação com o grupo controle. Além disso, as expressões de populações microbianas de metanogênicas no grupo CPEG apresentaram tendência menor do que nos grupos SPEG e controle. As conclusões mais salientes do presente estudo foram que, usando planta rica em tanino em dietas de pequenos ruminantes, poderemos ter mais benefícios em termos de substituição da fonte de proteína da dieta (segurança alimentar) e redução da produção de CH4 entérico
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Bioatividade de vidros contendo nióbio : estudo experimental in vivo / Bioactivity of glasses composed by niobium : an experimental in vivo studySouza, Lucas Pereira Lopes de, 1989- 25 August 2018 (has links)
Orientador: José Angelo Camilli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T16:59:30Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014 / Resumo: Alguns estudos mostram que a introdução do óxido de nióbio (Nb2O5) na composição do Bioglass® poderia ser uma solução para melhorar sua resistência mecânica, mantendo sua biocompatibilidade e bioatividade, porém, apesar da melhora na resistência mecânica causada pela adição deste óxido ser bem documentada na literatura, suas propriedades bioativas ainda são pouco conhecidas. Neste contexto, o objetivo do presente estudo foi avaliar experimentalmente as propriedades bioativas do óxido de nióbio em ratos albinos (Rattus norvegius) da linhagem Wistar. Para isso, bastões vítreos compostos por diferentes concentrações do Nb2O5 foram implantados na tíbia de ratos. Além disso, cada vidro teste, na forma de pó, foi implantado no músculo de ratos para análise de suas propriedades pró-angiogênicas, usando o Bioglass 45S5 (Bioglass®) como controle. As eutanásias foram realizadas 14 e 28 dias pós-cirurgias. Lâminas histológicas de cortes transversais das tíbias foram coradas a H&E para mensuração da área de osso subperiostal existente na cortical adjacente ao implante e a quantidade de osso esponjoso formado ao redor do bastão vítreo nos grupos de 14 dias, bem como da espessura da lâmina óssea formada ao redor do bastão nos grupos de 28 dias. Foi ainda realizada marcação imuno-histoquímica e a razão entre a área total do implante em mm2 e o número total de vasos sanguíneos contados manualmente num aumento de 400x para verificação a capacidade do material de estimular a angiogênese. A avaliação histológica revelou a ausência total de inflamação tanto após 14 quanto após 28 dias de implante. Os resultados das comparações entre as áreas de osso subperiostal dos grupos após 14 e 28 dias (feitas através de um teste ANOVA com post hoc tukey) e da quantidade de osso esponjoso formado ao redor do implante nos grupos 14 dias (feitas através do teste Kruskal-Wallis com Mann-Whitney como post hoc) mostraram que o BGPN1.3 apresentou maior capacidade de induzir a formação óssea do que o grupo controle, já com relação ao número de vasos sanguíneos e espessura da lâmina óssea formada ao redor do implante todos os grupos apresentaram resultado semelhantes. Assim, se concluiu que o BGPN1.3 trata-se de um material inovador por ser biocompatível, apresentar propriedade osteoindutiva superior e capacidade pró-angiogênica semelhante ao Bioglass® / Abstract: Some studies show that the introduction of niobium oxide (Nb2O5) into Bioglass® composition could be a solution to improve its mechanical strength while maintaining its biocompatibility and bioactivity, but in spite of improvement in resistance caused by addition of the oxide is well documented in the literature, their bioactive properties are still poorly known. In this context, the aim of this study was to experimentally evaluate the bioactive properties of niobium oxide in albino rats (Rattus norvegius). For this, glassy rods composed of different concentrations of Nb2O5 were implanted in the rats¿ tibia. In addition, each test glass in powder form was implanted into the muscle of mouse for analysis of their pro-angiogenic properties using 45S5 Bioglass (Bioglass®) as control. Euthanasia were performed 14 and 28 days post-surgery. Histological slides of cross sections of tibiae were H & E stained for measuring the area of existing subperiosteal bone in adjacent to the implant and the amount of cancellous bone formed around the vitreous rod after 14 days pos-surgery as well as the thickness of the formed bone sheet around the rod in groups of 28 days. It was also performed immunohistochemical staining to calculate the ratio between the total area in mm2 of the implant and the total number of blood vessels, counted manually using a magnification of 400x, to check the capacity of the material to stimulate angiogenesis. Histological evaluation revealed the complete absence of inflammation after both 14 and after 28 days of implantation. The results of the comparisons between the areas of subperiosteal bone of groups after 14 and 28 days (made by an ANOVA with Tukey post hoc test) and the amount of cancellous bone formation around the implant in the groups 14 days (done by Kruskal -Wallis with Mann-Whitney post hoc) revealed that BGPN1.3 showed greater ability to induce bone formation than the control group, when compared the number of blood vessels and thickness of the blade bone formed around the implant all groups showed similar results. Thus, we concluded that BGPN1.3 is an innovative material to be biocompatible and display better osteoinductive property than Bioglass® showing similar pro-angiogenic capacity / Mestrado / Anatomia / Mestre em Biologia Celular e Estrutural
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Efeito da interferência por RNA sobre o Schistosoma mansoni, Sambon, 1907 / The effect of RNA interference on the Schistosoma mansoni, Sambon, 1907Simões, Luciana Franceschi, 1980- 25 August 2018 (has links)
Orientador: Eliana Maria Zanotti Magalhães / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T23:25:44Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014 / Resumo: A busca de novos tratamentos para a esquistossomose é relevante devido a constatação de linhagens do Schistosoma mansoni com perda de sensibilidade aos fármacos atuais. A interferência por RNA (RNAi) é uma técnica que pode ser usada no silenciamento de um gene especifico, através de um RNA dupla fita (dsRNA). Essa ferramenta se mostra eficaz em aplicações terapêuticas em vírus, príons e patógenos intracelulares. Estudos mostram que a técnica do RNAi é bastante eficiente no verme Caenorhabditis elegans. Até o momento poucos trabalhos analisaram a técnica de RNAi no combate a esquistossomose. Este trabalho teve como objetivo aplicar a técnica da interferência por RNA em S. mansoni e avaliar sua eficiência em testes in vitro e in vivo, tendo como alvo o gene fucosiltransferase, enzima envolvida no processo de fucosilação de lipídios e proteínas essenciais ao parasita e o gene glicosilfosfatidilinositol, que atua como ancora de superfície, na qual se ligam antígenos protéicos e glicoprotéicos. A supressão gênica foi estudada em testes in vitro e in vivo, com observações da atuação na biologia, morfologia e mortalidade dos vermes. Como resultados nos testes in vitro, obtiveram-se alterações tegumentares nos adultos, extravasamento do conteúdo interno de fêmeas e alterações na oviposição, apresentando os grupos tratados maior quantidade de ovos mortos e malformados quando comparados com os grupos controles. Nos experimentos in vivo verificou-se diminuição no numero de vermes recuperados, mortalidade de vermes em alguns grupos tratados, e alteração na oviposição, quando examinados pelas técnicas de Kato e oograma. Análise histológica do fígado mostrou diferenças no número, na área e na conformação dos granulomas dos grupos tratados quando comparados com os grupos controles. A mortalidade de ovos eliminados nas fezes de camundongos após dois dias de tratamento também se mostrou significativamente maior nos grupos tratados com moléculas para silenciamento. Esses resultados sugerem o potencial uso da técnica de RNAi no estudo da esquistossomose / Abstract: The search for new schistosomiasis treatments is relevant due to the observation of resistant Schistosoma mansoni strains for current drugs. The interference by RNA (RNAi) is a technique which can be used for silencing a specific gene using a double strain RNA (dsRNA). This methodology presents efficacy in therapeutic use in virus, prions, and intracellular pathogens. Studies demonstrate that RNAi technique is very efficient in Caenorhabditis elegans worm. Up to the moment, a few studies have analyzed the RNAi technique against schistosomiasis. Thus, the aims of this study were apply the interference by RNA in S. mansoni and evaluate its efficiency in in vitro and in vivo tests, having the fucosyltransferase gene, an enzyme involved in parasite essential lipids and proteins fucosilation process, and the glicosylfosfatidilinositol gene, which acts as anchor-surface where proteic and glicoproteic antigens are bonded, as targets. The genic suppression was studied in in vitro and in vivo tests, with observation of its action in the biology, morphology, and mortality of the worms. The results for in vitro testswere integumentary alteration in adults, internal content extravasation in females, and oviposition alteration, with higher amount of dead eggs and not well formed eggs in the treated groups in comparison with the control groups. The in vivo tests presented a decrease in the number of recovered worms, worm mortality in some groups, and oviposition alteration when analyzed under the Kato and oogram techniques. Histological analysis of the liver presented differences in the number, area, and conformation of the granulomas of the treated groups in comparison with the control groups. The mortality of the eggs eliminated on the mice feces after two days of treatment were also significantly higher in the groups treated with the silencing molecules. These results suggest the potential use of the RNAi technique in the schistosomiasis treatment / Doutorado / Relações Antrópicas, Meio Ambiente e Parasitologia / Doutora em Biologia Animal
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Recherche et caractérisation d'antigènes vaccinaux contre Campylobacter par vaccinologie inverse / Research and characterization of vaccine antigens against Campylobacter by reverse vaccinologyMeunier, Marine 24 April 2017 (has links)
Les campylobactérioses sont les infections intestinales bactériennes d’origine alimentaire les plus fréquemment rapportées au sein de l’Union Européenne et sont principalement associées à la consommation de viande de volailles. Une diminution de la colonisation intestinale des volailles par Campylobacter de 2 à 3 log10 UCF/g permettrait de réduire l’incidence des cas humains de 76 à 100 %. La vaccination aviaire constitue un moyen de lutte potentiel mais, malgré de nombreuses études, aucun vaccin commercial n’est actuellement disponible. L’objectif de ce projet a été d’identifier de nouveaux antigènes vaccinaux contre Campylobacter en appliquant la stratégie de la vaccinologie inverse et d’évaluer leurs pouvoirs immunogène et protecteur contre la colonisation intestinale des volailles. Sur la base de leur localisation subcellulaire, leur antigénicité, leur densité en épitopes B et leur homologie de séquence avec l’ensemble des souches de C. jejuni et C. coli, quatorze antigènes ont été sélectionnés. Six d’entre eux ont été produits et testés in vivo en appliquant un protocole vaccinal optimisé. Quatre antigènes ont montré des diminutions significatives de la charge intestinale des oiseaux de 2 à 4,2 log10 UFC/g associées à l’induction de réponses humorales spécifiques. L’immunogénicité de ces candidats vaccins et l’efficacité protectrice de deux antigènes ont été observées à nouveau. Ces premiers résultats montrent l’intérêt et la fiabilité de la vaccinologie inverse. L’évaluation du potentiel vaccinal de ces nouveaux antigènes doit être poursuivie et approfondie lors de futures expérimentations. / Campylobacteriosis is the most prevalent bacterial foodborne gastroenteritis reported in the European Union and is mainly associated to consumption of poultry meat. Reducing the intestinal colonization of broilers by Campylobacter from 2 to 3 log10 CFU/g could decrease human cases incidence by 76 to 100%. Vaccination of poultry could be a potential strategy but despite many studies, no efficient vaccine is available yet. The aim of this project was to identify new vaccine antigens against Campylobacter using the reverse vaccinology strategy and to assess their immune and protective powers against the avian intestinal colonization. Based on their sub-cellular localization, immunogenicity, B-epitopes density and their sequence conservation among C. jejuni and C. coli strains, fourteen antigens were selected. Six out of them were produced and in vivo tested according to an optimized avian vaccine protocol. Four antigens showed intestinal load decreases from 2 to 4.2 log10 CFU/g correlated with the induction of specific humoral responses. Vaccine candidates’ immunogenicity and the protective efficiency of two antigens were observed again. These first results highlight the interest and reliability of the reverse vaccinology. The assessment of these new antigens vaccine potential needs to be continued and deepened in next experiments.
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Validation pré-clinique d'un produit d'ingénierie vasculaire à base d'hydrogel de chitosane / Pre-clinical validation of chitosan hydrogels for vascular engineeringBiscay-Aussel, Audrey 05 December 2017 (has links)
Objectifs. Les substituts vasculaires synthétiques sont à l’origine de nombreux échecs pour le remplacement des vaisseaux de petit calibre. L'émergence de l'ingénierie vasculaire ouvre des perspectives face à ce problème de santé publique. Le chitosane, polymère naturel, peut être utilisé comme matrice en ingénierie vasculaire. L'objectif de cette thèse était de produire des hydrogels de chitosane et d’étudier les propriétés mécaniques, biologiques et la biointégration. Matériel et Méthodes. Les hydrogels ont été caractérisés mécaniquement in vitro. En augmentant la concentration en chitosane, la résistance à la suture, à l’éclatement et les modules élastiques augmentaient de manière significative. Une série d'expériences, allant de l’évaluation in vitro à l’analyse in vivo de la biocompatibilité a été réalisée. In vitro, les hydrogels permettaient la prolifération des progéniteurs endothéliaux (EPCs) et étaient hémocompatibles. In vivo, les hydrogels n’étaient pas résorbés après 60 jours, dans un modèle d'implantation hétérotopique chez le rat. De plus, la biointégration du chitosane a été étudiée. In vitro, l’endothélium à la surface des hydrogels se comportait comme celui d’un vaisseau natif. In vivo, les hydrogels de chitosane étaient capables de moduler la réponse inflammatoire, dans un modèle d'implantation ectopique chez le rat, en favorisant la polarisation des macrophages vers le phénotype M2. Enfin, 2 tubes de chitosane ont été implantés avec succès pour des pontages carotidiens pendant 3 jours chez le mouton. Conclusion. En modulant la concentration de chitosane, nous avons produit des matrices avec des propriétés adaptées pour l’ingénierie vasculaire. / Aims. Vascular grafts made of synthetic polymers perform poorly in small-diameter applications. Consequently, there is strong clinical to produce small caliber vessels with better patency. The emergence of vascular engineering opens new possibilities. Chitosan, a natural polymer, can provide a scaffold for vascular engineering. The goal of this thesis was to produce chitosan-based hydrogels and to assess their biological and mechanical properties and their biointegration. Methods and Results. Hydrogels were mechanically characterized in vitro. By increasing chitosan concentration, suture retention value, average burst strength and elastic moduli increased significantly. A series of experiments ranging from in vitro biocompatibility tests to in vivo studies was performed. In vitro, chitosan supported human endothelial progenitor cells (EPCs) proliferation and was hemocompatible. In vivo, no resorption of chitosan was observed in a rat heterotopic implantation model. In addition biointegration of chitosan hydrogels were investigated. In vitro, chitosan endothelialized with EPCs behave as a native endothelium. In vivo, chitosan hydrogels were able of modulating the inflammatory response of injured host tissue by favouring polarization of macrophages towards the beneficial M2 phenotype in a rat ectopic implantation model. Finally, as a proof of concept, 2 chitosan tubes were implanted successfully as carotid interposition grafts for 3 days in sheep. Conclusion. By modulating chitosan concentration, we produced scaffolds with suitable properties to be implanted in vivo.
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Contribution biomécanique à l'analyse cinématique in vivo des mouvements de la main humaine / Biomechanical contribution to the in vivo kinematic analysis of the human hand motionDevos, Pierre 12 May 2017 (has links)
La main est l’organe de préhension chez l’homme qui lui permet de manipuler des objets de tailles et de formes diverses et variées. Elle lui permet également d’effectuer des tâches, parfois d’une grande complexité, avec force ou avec une grande finesse. Il s’agit d’un outil d’une importance cruciale au quotidien, tant sur le plan domestique que sur le plan professionnel, et la perte de fonctionnalité de la main peut rapidement devenir un handicap pour certaines personnes. Bien qu’il existe encore peu d’études sur la capture et l’analyse des mouvements de la main dans la littérature scientifique, de nombreux domaines comme la médecine, l’ergonomie, le sport, la robotique, la réalité virtuelle ou les jeux vidéo s’y intéressent de plus en plus, afin de permettre aux personnes d’exploiter au mieux les fonctionnalités de la main tout en la préservant, ou de créer des interfaces homme-machine afin que celui-ci puisse interagir avec des robots ou en environnement virtuel. L’objectif de cette thèse a été de développer une méthode d’analyse cinématique in vivo et personnalisée afin de contribuer à une meilleure compréhension des mouvements de la main de l’homme. Une première partie du travail consiste à mettre en place un protocole de capture du mouvement de la main sur des sujets masculins et féminins de différentes tranches d’âges, allant de 20 à 50 ans. Les captures de mouvement ont été effectuées à l’aide d’un système optoélectronique et de 56 marqueurs passifs collés sur la peau de la main du sujet. Deux types de mouvements ont été capturés : les mouvements fonctionnels en flexion-extension et en abduction-adduction de la main, et les mouvements de prise d’objets cylindriques et sphériques. Les captures de mouvement sont ensuite labellisées afin d’identifier les différents marqueurs et de pouvoir en extraire les trajectoires. La deuxième partie du travail consiste à développer une méthode d’analyse cinématique des mouvements externes de la main à partir des trajectoires des marqueurs et de la valider à l’aide d’un modèle in silico. En plus d’estimer les paramètres cinématiques avec précision dans le cas où les trajectoires des marqueurs sont parfaites, l’évaluation des méthodes fonctionnelles montre que les mouvements de la main sont assimilables à des mouvements plans, circulaires ou sphériques en fonction de l’articulation étudiée. La construction des repères fonctionnels à partir des paramètres cinématiques pour chaque segment de la main permet ensuite de décrire les mouvements de rotation des articulations à l’aide des angles de Cardan. Les courbes des angles de Cardan obtenues à partir des trajectoires des marqueurs du modèle in silico permettent de valider la méthode de décomposition développée pour l’ensemble des articulations, à l’exception des articulations trapézo-métacarpienne (TMC) et métacarpo-phalangienne (MCP1) du pouce qui sont plus difficiles à analyser. La dernière partie de ce travail de thèse consiste à analyser les mouvements fonctionnels et les mouvements de prise d’objets à partir des captures expérimentales. Les courbes des angles de Cardan obtenues à partir des mouvements fonctionnels correspondent globalement à celles obtenues dans la littérature, sauf dans le cas de l’articulation TMC. De plus, ces courbes montrent que les rotations articulaires ne s’effectuent pas uniquement autour d’un axe, mais autour d’un axe de rotation dominant et d’un ou deux axes de rotation secondaires. Toutefois, les courbes des angles de Cardan des rotations autour des axes secondaires ne correspondent pas toujours à celles présentées dans la littérature. Bien que peu de mouvements de prise d’objets aient pu être analysés, certaines corrélations intéressantes ont pu être trouvées entre les postures de la main et la géométrie des objets manipulés, notamment au niveau des articulations MCP et IPD. / The human hand is a prehensile organ which allows people to handle objects with various sizes and shapes. It is wonderful tool that can be used to perform different simple or complex tasks with strength or great dexterity. It is also a crucial tool in the daily life, both at home and in the workspace, and loss of hand functionality may quickly become disabling for some people. There are few studies in the literature. However, motion capture and kinematic analysis of the hand is becoming more and more of an interest in different areas such as medicine, ergonomics, sport, robotics, virtual reality and video games. Results from these studies have improved knowledge about skills of the hand and how to preserve them. The studies have also improved interactions between people and computers in order to command robots or to progress in virtual reality. The aim of the thesis was to develop methods for an in vivo and subject-specific kinematic analysis in order to contribute to the improvement of knowledge about the human hand motion. A first part of this thesis was to develop a protocol for the motion capture of the hand for male and female subjects aged from 20 to 50 years old. The motion capture was performed using an optoelectronic system with passive markers glued on the skin of the hand. Two sorts of movements were captured. Firstly, functional movements like flexion-extension and abduction-adduction. Secondly, prehensile movements of cylindrical and spherical objects. Then, markers on the motion captures were identified in order to extract their trajectories. The second part of this thesis consisted in the development of a method for the kinematic analysis of external hand movements from the marker trajectories. Validation of this method was achieved using a model of the hand developed in silico. Since no noise was added to the marker trajectories in the silico model; kinematic parameters were estimated with precision. Moreover, assessment of the functional methods showed that the hand motions can be approximated by a plane, a circular arc or a spherical cap depending on the joint studied. After constructing the functional coordinate systems for each segment of the hand using the joint kinematic parameters, it was possible to decompose any joint rotation into three Cardan angles. This decomposition method was validated using the marker trajectories of the hand model, except for the trapeziometacarpal (TMC) and the metacarpophalangeal (MCP1) joints of the thumb which are more difficult to study. The last part of this thesis consisted in the analysis of the functional and the prehensile movements from the motion captures. The curves of the Cardan angles obtained from the functional movements are similar to those presented in the literature for all of the joints, except for the TMC joint. It was also noticed that the joint rotations do not occur around only one axis, but around one dominant axis and one or two secondary axes. However, some differences between the curves of the Cardan angles around the secondary axes obtained in this thesis and those presented in the literature were noticed for some joints. Despite only few prehensile grasps were analyzed, some interesting correlations were also found between the hand shape and the objects grasped, more particularly at the metacarpophalangeal (MCP) and the distal interphalangeal (DIP) joints.
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Scandium complexes : physico-chemical study and evaluation of stability in vitro and in vivo for nuclear medicine application / Complexes de Scandium : étude physico-chimique et évaluation des stabilités in vitro et in vivo pour des applications en médecine nucléaireKerdjoudj, Rabha 04 December 2014 (has links)
Parmi les différents isotopes du Scandium qui peuvent être utilisés en médecine nucléaire, on peut citer le ⁴⁷Sc et le ⁴⁴Sc. Le premier se désintègre en émettant un électron associé à un gamma de 159 keV et peut donc être utilisé soit pour faire de la radiothérapie, soit de l’imagerie TEMP. Le ⁴⁴Sc (3.97 h) se désintègre dans 94.27 % des cas en émettant un positron, accompagné d’un photon γ d’énergie égale à 1.157 MeV. Cet isotope est alors un candidat idéal pour des applications en imagerie TEP. Actuellement, le Cyclotron de haute énergie et haute intensité Arronax produit le ⁴⁴Sc et coproduit son état isomérique le ⁴⁴mSc (2.44 j). Le ⁴⁴mSc a des propriétés (Eᵧ=270 keV, 98.8 %) qui permet d’envisager son utilisation comme potentiel générateur in vivo. Les travaux précédents ont permis de montrer que le ligand DOTA est le plus adapté et le plus stable pour le Sc. Ce travail de thèse a pour but de mettre en évidence la faisabilité du générateur in vivo ⁴⁴m/⁴⁴Sc. Dans un premier temps une procédure a été optimisée et validée pour la production du ⁴⁴m/⁴⁴Sc avec une haute activité spécifique et pureté chimique. Le radiomarquage sur des peptides contenant du DOTA a été ensuite développé et optimisé. Des études théoriques et expérimentales ont été réalisées dans le but de démontrer la faisabilité du ⁴⁴m/⁴⁴Sc comme potentiel générateur in vivo. En fin des études de stabilité in vitro sur des complexes radiomarqués du ⁴⁴m/⁴⁴Sc suivi d’études de biodistribution et d’imagerie TEP ont été réalisées. / Among the different isotopes of Scandium that can be used in nuclear medicine may be mentioned the ⁴⁷Sc and ⁴⁴Sc. The first decays by emitting an electron associated with a 159 keV gamma can thus be used either for radiotherapy or TEMP imaging. The ⁴⁴Sc (3.97 h) decays in 94.27% in case by emitting a positron, with a γ photon energy equal to 1.157 MeV. This isotope is then an ideal candidate for applications in PET imaging. Currently, the Cyclotron of high energy and high intensity ARRONAX produce ⁴⁴Sc and co-produces the isomeric state the ⁴⁴mSc(2.44 d). The ⁴⁴mSc has properties (Eᵧ = 270 keV, 98.8%), which allows to consider its use as a potential in vivo generator. Previous work had demonstrated that the DOTA ligand is most suitable and stable for Sc. This thesis aims; make in evidence the feasibility of the in vivo ⁴⁴m/⁴⁴Sc generator. Initially a procedure was optimized and validated for the production of ⁴⁴m/⁴⁴Sc with a high specific activity and chemical purity. Radiolabeling of DOTA conjugated peptides was then developed and optimized. Theoretical and experimental studies have been performed in order to demonstrate the feasibility of ⁴⁴m/⁴⁴Sc as a potential in vivo generator. Finally, in vitro stability studies on radiolabeled ⁴⁴m / ⁴⁴Sc complexes were performed, followed by biodistribution studies and PET imaging.
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Investigations into rat hepatobiliary drug clearance pathways in early drug discoveryRynn, Caroline January 2014 (has links)
Conventional ‘well-stirred’ extrapolation methodology using intrinsic metabolic clearance data from rat liver microsomes poorly predicts in vivo clearance for approximately half of drug discovery compounds. The aim of this present study was to gain a more detailed understanding of the hepatobiliary disposition pathways which influence drug clearance. A set of 77 new chemical entities (NCEs), demonstrating a range of physicochemical properties and in vitro-in vivo clearance correlations (IVIVC), were employed to explore relationships between hepatobiliary disposition pathways in rat and physicochemical, structural and molecular properties of the NCEs. Primary rat hepatocytes with >80% cell viability were successfully isolated from male Han Wistar rats and used to establish in vitro models of drug uptake and biliary efflux. Preliminary studies with cultured primary rat hepatocytes indicated that uptake of d8-taurocholic acid and pitavastatin was time, concentration and temperature dependent. Initial studies with sandwich cultured primary rat hepatocytes demonstrated that cellular accumulation and biliary efflux of [3H]-Taurocholic acid was time and concentration dependent. These in vitro rat hepatocyte models were then used to investigate drug uptake and biliary efflux for all NCEs. In general, NCEs with high (passive) permeability showed better IVIVC and a lower incidence of active uptake and biliary efflux compared to NCEs with lower permeability, suggesting permeability is a key property influencing hepatobiliary drug disposition in rat. Preliminary in silico models analysing structural and molecular descriptors of substrates of active transport in rat hepatocytes were developed and indicated modest potential to highlight clearance pathways beyond hepatic metabolism but further follow up work with larger, more diverse compound sets is warranted to gain confidence in these models. Extended clearance models were investigated to estimate the effect of hepatic transporters on clearance and to predict the overall hepatic clearance of the NCEs. None of these models resulted in a 1 to 1 correlation but in general, improvements in clearance predictions were made when drug transport processes were accounted for. In vivo excretion studies using bile duct cannulated rats demonstrated that NCEs with high permeability and good IVIVC were not directly eliminated in bile or urine as unchanged drug, whereas NCEs with lower permeability and poor IVIVC (> 3-fold under predicted) were all directly eliminated unchanged indicating key drivers of clearance beyond metabolism. In conclusion these investigations confirmed a role for hepatic transporters in clearance but the complex nature of active transport mechanisms and a lack of robust in vitro tools create challenges in the quantitative prediction of hepatobiliary clearance. However, one of the key findings from this research, which is highly applicable in early drug discovery, was to identify the existence of disposition permeability relationships. These can be anticipated by observing physicochemical parameters of NCEs in conjunction with conventional IVIVC, since NCEs that are not highly permeable, possess some hydrophobic characteristics, and which are poor substrates of cytochrome P450 enzymes are more likely to be good substrates of transporters and be directly eliminated in bile and/or urine. The present study focused on exploring hepatobiliary disposition pathways using rat as the investigative species. Whilst there is no guarantee that pathways relevant to rat will be similar to other preclinical species or even humans, an early diagnosis of dominant clearance pathways can guide a more efficient use of the ADME-PK toolbox.
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