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Problematika nelegální migrace a možnosti jejího řešení / The issue of illegal migration and various approaches to its solutionPROCHÁZKOVÁ, Lenka January 2008 (has links)
This thesis deals with the issue of illegal migration in the Czech Republic and various approaches to its solution. First of all, it provides a complex survey of the problem. It views the problem in the context of international migration, labor migration and the legislative framework of the Czech Republic, as regards its relation to foreigners. The goal is to compare and evaluate individual possibilities of dealing with illegal migration from the point of view of governmental and non-governmental institutions, and to propose an optimal solution. The thesis presents indepth interviews with representatives of seven different institutions. It turns out that particular solutions of illegal migration can not be separated, rather they must be viewed in the context of all other solutions. The priorities of the fight with illegal migration are the following: cooperation with countries of origin, enlightenment of both, potential immigrants as well as their potential employers, getting rid of ``push{\crqq} factors in countries of origin, and elimination of the main ``pull{\crqq} factor which is the possibility of getting an illegal job in the target country. The main output of my thesis research is pinpointing recommendations and conclusions which should be considered when looking for an optimal solution to the issue of illegal migration. I also present a few hypotheses for further research. When looking for an optimal solution the crucial task is played by the high-quality discussion on both levels, the professional as well as the public one. I suppose that this work has enhanced such discussion, furthermore, it can enhance such debate in the future too.
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Estratégia de planejamento de produção e os sistemas ERP em ambientes sujeitos ao fenômeno hockey-stick. / Production planning strategy and ERP systems in environments subject to the hockey-stick phenomenon.Renato Gioielli Basso 18 August 2015 (has links)
O ambiente competitivo atual tem colocado pressão no processo de tomada de decisão no mundo corporativo. Os trade-offs das prioridades competitivas discutidos na elaboração da estratégia como custo, qualidade, serviço e flexibilidade já não são suficientes. Estes trade-offs, embora importantes no curto prazo, devem ser compatibilizados de modo que as empresas que tenham o melhor balanço entre eles devam ter resultado superior. Um dos trade-offs bastante discutido é o equilíbrio entre serviço e estoque. A percepção é que seja improvável alcançar excelência no serviço sem ter um considerável nível de estoque. Deste cenário nasce então o paradoxo do uso de sistemas MRP (Material Requirement Planning) versus sistemas JIT (Just in Time), ou melhor, sistemas empurrados versus puxados, já que a escolha por um ou outro sistema tem ligação íntima com a gestão de estoque. Se por um lado os sistemas MRP são largamente utilizados, via softwares ERP, por outro sistemas JIT têm trazido importantes melhorias nos resultados. Embora muitas empresas considerem a adoção exclusiva de um ou outro sistema, algumas delas têm adotado um processo híbrido com o objetivo de tirar o melhor de cada sistema e gerar assim desempenho superior. O objetivo deste trabalho é investigar como as empresas inseridas em mercados caracterizados pela concentração de demanda no final do mês (fenômeno conhecido como hockey-stick), e baixo acerto nas previsões de demanda, estão aplicando suas estratégias de planejamento de produção e seus ERP. Se por um lado a baixa acurácia nas previsões causa um problema na aplicação de estratégias empurradas de planejamento, pois requer um alto estoque de segurança associado, por outro a concentração de embarque dificulta a adoção de uma estratégia puramente puxada, já que o sistema não tem a estabilidade necessária. Para cumprir com este objetivo seis estudos de caso foram conduzidos e os resultados encontrados, suportados pela teoria, sugerem o aparecimento de um modelo híbrido eficaz para planejamento no ambiente estudado assim como o aparecimento de um sistema DSS (Decision Support System). Outra contribuição desta pesquisa foi identificar, em um dos casos, uma empresa que conseguiu atacar de maneira eficaz o fenômeno em sua causa raiz neutralizando assim seus efeitos. / The highly competitive environment of modern times has put pressure on the decision-making process in the corporate world. The trade-offs of competitive priorities such as cost, quality, service and flexibility are no longer enough. These trade-offs, albeit important in the short term, must be matched so that companies that have the best balance between them should have superior results. One of the tradeoffs widely discussed is the balance between service level and inventory. The perception is that excellence is not likely to be achieved in service without having a significant level of inventory. From this scenario comes the paradox of using MRP systems (Material Requirement Planning) versus JIT systems (Just in Time), or rather \"pushed\" systems versus \"pulled\" systems since the option for one or the other system has a close connection with inventory management. On the one hand, MRP systems are widely used in industry through ERP software; on the other hand, JIT systems have obtained better results. While many companies consider adopting one or another system, some of them adopt a hybrid process with the goal of taking the best of each system and generate superior performance. The purpose of this research is to investigate how companies inserted in markets characterized by sales peak at the end of the month (hockey-stick phenomenon), and low accuracy in demand forecasts, are applying their production planning strategies and their ERP. Low forecast accuracy causes a problem in applying pushed strategies as it requires a high safety stock associated. Conversely, the sales peak hinders the adoption of a purely pull strategy since the system does not have the necessary stability. To meet this goal, six case studies were conducted and the results found and supported by the theory suggest the emergence of an effective hybrid model for planning in the environment studied as well as the appearance of a DSS (Decision Support System). Another contribution of this research was to identify in one of the cases a company that managed to effectively tackle the phenomenon in the root cause, neutralizing its effects.
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Fatores que influenciam na resistência de união - ensaios push out e pull out - de pinos intra-radiculares. Estudo in vitro / Factors that influence on fiber post bond strength - push out and pull out tests. In vitro studyDenis Yudi Nagase 03 July 2012 (has links)
Objetivo: Este estudo se propõe a verificar a influência do adesivo, material de preenchimento e hibridização da dentina na força de retenção de pinos intra-radiculares na técnica direta indireta e comparar o teste de tração de push out com o pull out. Métodos: 60 raízes de dentes bovinos com comprimento de 12 mm foram tratadas endodonticamente e divididas aleatoriamente em 6 grupos (n=10): grupo 1 (técnica direta-indireta, adesivo fotopolimerizável, cimento resinoso, teste de pull out); grupo 2 (idem ao grupo 1 porém o cimento resinoso foi substituído pela resina composta); grupo 3 (idem ao grupo anterior porém o adesivo fotopolimerizável foi substituído pelo químico); grupo 4 (idem ao anterior porém o teste utilizado foi o de push out); grupo 5 (idem ao grupo anterior porém o adesivo utilizado foi o auto condicionante); e grupo 6 (idem ao grupo anterior porém a dentina foi pré hibridizada). A força de retenção foi determinada através do teste de tração usando Universal Testing Machine (Instron). Todos os dados foram analisados usando one-way analysis of variance (ANOVA) com a significância de p<0.05 e complementadas com teste de Tukey. Após o teste, as interfaces adesivas onde ocorreram as falhas foram examinadas e classificadas. Resultado: Houve diferença estatística na comparação de materiais (adesivo, material de preenchimento). A hibridização da dentina não apresentou melhoras na retenção dos pinos . A maior parte das fraturas ocorreu na interface dentina/resina. Conclusão: Com base nos resultados obtidos, concluímos que material de preenchimento, o tipo de adesivo, influenciaram na retenção de pinos de fibra; e a pré-hibridização da dentina não apresentou melhoras a retenção dos pinos. O teste de push out apresentou mais detalhes para verificar o valor da adesão de cada terço da raiz; e o teste de pull out, para a força de retenção do pino ao longo do interior do conduto e o tipo de falha. / Objective: The aims of this study is to verify the influence of adhesive, filling material and dentin hybridization on fiber post retention force in diretc -indirect technique and compare the tensile test of push out with pull out. Methods: 60 bovine single roots with a length of 12 mm were endodontically treated and randomly divided into 6 groups (n = 10): group 1 (direct-indirect technique, light-curing adhesive, resin cement, pull out test), group 2 (same as group 1 but the resin cement was replaced by composite resin), group 3 (same as previous group but the light-curing adhesive was replaced by the chemical), group 4 (same as group 3 but the test was used was push out test), group 5 (same as group 4 but the adhesive used was the self etching) and Group 6 (same as previous group but the dentin was pre-hybridized). The retention force was determined by Universal Testing Machine (Instron). All data were analyzed using one-way analysis of variance (ANOVA) with significance of p <0.05 and complemented with Tukey test. After testing, the adhesive interfaces were examined and classifie. Result: There was a significant difference between comparison of materials (adhesive and filling material). The hybridization of dentin showed no improvement in the retention post. Most fractures occurred at the interface dentin / resin. Conclusion: Based on the results, we conclude that filling material, adhesive, influenced the retention of fiber posts, and the prehybridization of dentin did not improve the retention of fiber post. The push out test showed more details to verify the bonding between the post and dentin, and the pull out test for the retention force of the post inside the canal.
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Análise da expressão e das interações da subunidade catalítica da PKA do fungo patogênico Paracoccidioides ssp. / Analysis of the expression and interactions of the catalytic subunit of PKA in pathogenic fungus Paracoccidioides ssp.Teixeira, Mirian Vieira 10 March 2016 (has links)
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Previous issue date: 2016-03-10 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The Paracoccidioides genus comprises a complex of pathogenic fungi that are the etiologic agents of paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in Latin America. The infection begins after inhalation of fungal propagules, which reach the epithelium of the alveoli where the transition from the mycelial to the pathogenic yeast form. Host elevated temperature triggers the morphological switch, which is necessary for fungal pathogenicity. The cAMP/protein kinase A (PKA) signaling pathway has been shown to be important in controlling morphological changes and the pathogenicity of several pathogenic fungi. Evidence also highlights the importance of the cAMP/PKA pathway in the morphological transition of Paracoccidioides. PKA is the major effector of this signaling pathway. The protein is an inactive tetramer composed of regulatory subunit, encoded by the BCY1 gene; and catalytic subunit, encoded by the TPK2 gene. Upon binding of cAMP to the regulatory subunits, the catalytic subunits dissociate and become active. Activated PKA subsequently phosphorylates protein kinases, transcription factors, and other substrates to control several biological processes. In this study, we evaluated the expression and interactions of Tpk2 protein Paracoccididioides spp. The Tpk2 is present in mycelium decreased during the initial stages of transition phases, and increases again at the end of differentiation, with maximal levels in yeast. We analyzed the interactions of recombinant Tpk2p with Paracoccidioides proteins using pull-down assays followed by MS analysis. Two interacting proteins were identified: the heat shock protein 90 (Hsp90) and a conserved hypothetical protein with a MFS domain. Hsp90 is involved in the regulation of morphogenesis, development and virulence in several thermal dimorphic fungi. These data are important for understanding the mechanisms that trigger the transition phases in Paracoccidioides. / O gênero Paracoccidioides compreende um complexo de fungos patogênicos, que são os agentes etiológicos da paracoccidioidomicose (PCM), a micose sistêmica mais prevalente na América Latina. A infecção inicia-se com a inalação de propágulos do fungo, que atingem o epitélio dos alvéolos pulmonares, onde ocorre à transição da forma de micélio para a forma patogênica, de levedura. Há evidências de que a temperatura seja o principal fator responsável pela diferenciação celular desses fungos, e sua patogenicidade é frequentemente associada com a transição dimórfica. A via de sinalização cAMP/ proteína quinase A (PKA) controla alterações morfológicas e de virulência/patogenicidade em várias espécies de fungos patogênicos humanos. Evidências apontam também para a importância da via cAMP/PKA em Paracoccidioides spp. A PKA é o principal efetor desta via de sinalização. A proteína na forma inativa é um tetrâmero composto de subunidade regulatória, codificada pelo gene BCY1; e subunidade catalítica, codificada pelo gene TPK2. Após a ligação de cAMP às subunidades regulatórias, as subunidades catalíticas dissociam-se e tornam-se ativas. Ativada a PKA fosforila proteína-quinases, fatores de transcrição, e outros substratos para controlar diversos processos biológicos. Neste estudo, avaliamos a expressão e as interações da proteína Tpk2 de Paracoccididioides spp. A Tpk2 está presente em micélio, diminui nos estágios iniciais da transição de fases e volta a aumentar no final da diferenciação, apresentando níveis máximos na levedura. Foram analisadas as interações de Tpk2p recombinante com proteínas de Paracoccidioides utilizando ensaios de pull-down, seguido por análise de MS. Foram identificadas duas proteínas que interagem: a proteína de choque térmico 90 (Hsp90) e uma proteína hipotética conservada com um domínio MFS. Hsp90 está envolvido na regulação da morfogênese, desenvolvimento e virulência em vários fungos dimórficos térmicos. Estes dados são importantes para entendimento dos mecanismos que disparam a transição de fases em Paracoccidioides spp.
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Clonagem e expressão heteróloga, modelagem e interações intermoleculares da enolpiruvilchiquimato 3-fosfato sintase de Paracoccidioides brasiliensis / Cloning and heterologous expression, modeling and intermolecular interactions of enolpiruvilchiquimato 3-phosphate synthase from Paracoccidioides brasiliensisCosta, Wanderson Lucas da 07 August 2017 (has links)
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Previous issue date: 2017-08-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Paracoccidioides spp. are thermodymorphic fungi that when inhaled by humans, these conidia find a favorable environment, changing to the yeast phase and becoming pathogenic causing paracoccidioidomycosis (PCM), one of the most prevalent systemic mycoses in Brazil. Some antifungals are used in the treatment of PCM. Treatment depends on the patient's progression and tolerability of each drug, but their treatment may be for long periods and cause various side effects in the patient. The chiquimate pathway is coordinated by 7 enzymes that perform consecutive steps to convert erythrose-4-phosphate and phosphoenol pyruvate (PEP) into chorismate. In microorganisms, this pathway is involved in the production of the amino acids phenylalanine, tyrosine and tryptophan; These amino acids are essential to the maintenance of these organisms. In this work, pGEX4T3 vector cloning and heterologous expression of Pb18 EPSP synthase belonging to the chiquimate pathway were performed. This protein was expressed in E. coli (DE3) strain and purified. Antibodies were produced for expression analysis of the protein in Western blot. The modeling of EPSP synthase was performed aiming to identify the amino acids involved in the active site. The pull down-GST assay with soluble Pb18 proteins allowed the identification of 40 proteins that interact with EPSP synthase. These proteins belong to different functional categories, which are involved with the availability of phosphoenol pyruvate, the substrate necessary for the functioning of the chiquimate pathway. / Paracoccidioides spp. são fungos termodimórficos que ao serem inalados pelo ser humano, esses conídios encontram um ambiente propício, mudando para a fase de levedura e tornando-se patogênico causando a paracoccidioidomicose (PCM), umas das micoses sistêmicas de maior prevalência no Brasil. Alguns antifúngicos são empregados no tratamento da PCM. O tratamento depende do avanço da doença e da capacidade de tolerância do paciente a cada medicamento, mas o seu tratamento pode ser por longos períodos e causando diversos efeitos colaterais no paciente. A via do chiquimato é coordenada pela ação de 7 enzimas que realizam passos consecutivos para transformar a eritrose-4-fosfato e fosfoenol piruvato (PEP) em corismato. Em micro-organismos, esta via está envolvida com a produção dos aminoácidos fenilalanina, tirosina e triptofano; estes aminoácidos são essenciais à manutenção desses organismos. Neste trabalho foi realizado a clonagem em vetor pGEX4T3 e expressão heteróloga da EPSP–sintase de Pb18 pertencente à via do chiquimato. Essa proteína foi expressa em linhagem E. coli (DE3) e purificada. Os anticorpos foram produzidos para análise da expressão da proteína em Western blot. A modelagem da EPSP-sintase foi realizada visando identificar os aminoácidos envolvidos no sítio ativo. O ensaio de pull down-GST com proteínas solúveis de Pb18 possibilitou a identificação de 40 proteínas que interagem com EPSP-sintase. Essas proteínas pertencem a diferentes categorias funcionais, as quais estão envolvidas com a disponibilidade de fosfoenol piruvato, substrato necessário para o funcionamento da via do chiquimato.
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Clonagem, expressão heteróloga, modelagem e interações intermoleculares da proteína corismato sintase de Paracoccidioides brasiliensis / Cloning, heterologous expression, modeling and intermolecular interactions of the chorismate synthase protein from Paracoccidioides brasiliensisSantana, Andrea Leite Camargo 29 March 2017 (has links)
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Previous issue date: 2017-03-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Paracoccidioides fungi are the causative agents of paracoccidioidomycosis, an endemic disease in Latin America with great socioeconomic importance. Inhalation of spores, the infectious particles of the fungus, is a common way to get the infection. Its treatment is slow and generates long-term side effects making it necessary to study new metabolic pathways that can be potential targets for antifungal development. In this context, stands out the chiquimate pathway in Paracoccidioides spp., related to the production of chorismate and production of aromatic amino acids, and the chorismate synthase involved in the last stage of this pathway. The chorismate synthase from Pb18 was cloned into pGEX-4T3 vector, expressed in pLysS cells and purified on a glutathione-sepharose column. Antibodies were produced from the immunization of mice with the recombinant protein obtained and used in Western blot assay to confirm protein expression. For characterization of the enzyme, its modeling was carried out. Pull-down-GST assay was performed to identify interactions between the chorismate synthase and soluble proteins present in total protein extract of Pb18. The interactions found included proteins of different functional categories related to protein synthesis, related with metabolism of common intermediates such as folate and quinolinate or related with the availability of ATP, phosphoenolpyruvate and erythrose-4-phosphate required in the chiquimate pathway. Unexpected interactions with proteins of the cell cycle and also with regulating proteins of the cell division process were observed. / Fungos do gênero Paracoccidioides são os agentes causadores da paracoccidioidomicose, uma doença endêmica na América Latina de grande importância socioeconômica. A inalação de esporos, partículas infecciosas do fungo, é uma forma comum
de adquirir a infecção. O seu tratamento é lento e gera efeitos colaterais tornando necessário o estudo de novas vias metabólicas que sejam potenciais alvos para o desenvolvimento de antifúngicos. Nesse contexto, destaca-se a via do chiquimato em Paracoccidioides spp., relacionada à obtenção de corismato e produção de aminoácidos aromáticos, sendo corismato sintase a enzima envolvida na última etapa dessa via. A corismato sintase proveniente de Pb18 foi clonada em vetor pGEX-4T3, expressa em células pLysS e purificada em coluna de glutationa-sefarose. Anticorpos foram produzidos a partir da imunização de camundongos com a proteína recombinante obtida e utilizados em ensaio de Western blot a fim de confirmar a expressão proteica. A modelagem da corismato sintase foi realizada e os aminoácidos envolvidos no sítio ativo foram identificados. Ensaios de pull-down-GST foram realizados a fim de identificar os complexos de interações entre a corismato sintase e proteínas solúveis presentes em extrato proteico total de Pb18. As interações encontradas incluíram proteínas de diferentes categorias funcionais relacionadas à síntese proteica, ao metabolismo de intermediários comuns como folato e quinolinato ou ainda com a disponibilidade de ATP, fosfoenolpiruvato e eritrose-4-fosfato necessários na via do chiquimato. Interações inesperadas com proteínas do ciclo celular e também com proteínas reguladoras do processo de divisão celular foram observadas.
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Desenvolvimento, caracterização e avaliação de um sistema osmótico do tipo bicamada / Development, characterization and evaluation of a bilayer osmotic release systemMiller Nunes de Freitas 23 January 2009 (has links)
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.
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Déterminants biotiques d'une interaction durable lâche : interactions entre un microprédateur hématophage, son hôte oiseau et les communautés d'acariens du fumier / Biotic determinants of sustainable loose interaction : interactions between blood-sucking micro-predator, its host bird and manure mite communities.El Adouzi, Marine 09 November 2017 (has links)
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.
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Matériaux « uniques » pour cellules solaires organiques mono-composant / « Unique » materials for single-component organic solar cellsLabrunie, Antoine 18 December 2017 (has links)
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.
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Synthèse et monocouches auto-assemblées de molécules "Push-Pull" / Synthesis and self-assembled monolayers of "Push-Pull" moleculesMalytskyi, Volodymyr 03 April 2015 (has links)
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.
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