Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The antioxidant effects of the hydro-alcoholic guaraná extracts (Paullinia cupana var. sorbilis Mart.) on nitric oxide (NO ) and other compounds generated from degradation of Sodium Nitroprusside (SNP) in embryonic fibroblast culture (NIH-3T3 cells) were evaluated. The guaraná bioactive compounds were initially determined by a high-performance liquid chromatography (HPLC): caffeine=12.240 mg/g, theobromine=6.733 mg/g and total catechins= 4.336 mg/g. To the experiments, initially the cells were grown in DMEM (Dulbecco s Modified Eagle Medium) medium and incubated in a humidified atmosphere of 5% CO2 and 37°C until reach 90% confluence. Cell cultures were exposed to 10μM SNP during six hours since in this concentration the cells present >90% mortality. Guaraná diluted in water was added in the cultures in five concentrations (0.5, 1, 5, 10 and 20 mg/mL). MTT and Trypan blue viability, biochemical oxidative markers and genotoxicity (DNA Comet assay) analysis were performed. Additionally, the cell oxidative stress was evaluated by 2,7 dihydrodichlorofluorescein diacetate (DCFDA) fluorescence assay by confocal microscopy. Guaraná reverted the SNP toxicity mainly in lower concentrations (<5 mg) decreasing cell mortality, lipid peroxidation, DNA damage and cell oxidative stress and increasing the SOD levels. However, guarana was unable to reverse the inhibition of catalase probably triggered by the presence of cyanide which is also produced in the decomposition of SNP. The results suggest that guarana has effects on the modulation of excessive amounts of NO probably through its antioxidant properties. These results supported previous studies that suggest guarana have a protective effect against morbidity as obesity and metabolic syndrome that are related to metabolism. / Os efeitos antioxidantes do extrato hidro-alcoólico de guaraná (Paullinia cupana var. sorbilis) sobre o Óxido Nítrico (NO ) e outros compostos gerados a partir da decomposição do Nitroprussiato de Sódio (NPS) em cultura de fibroblastos embriônicos (NIH 3T3) foram avaliados. Os compostos bioativos do guaraná foram inicialmente determinados por cromatografia líquida de alta performance (HPLC): cafeína=12,240 mg/g, teobromina=6,733 mg/g e catequinas totais=4,336 mg/g. Para os experimentos as células foram inicialmente cultivadas em meio DMEM (Dulbecco s Modified Eagle Medium) e incubadas em uma atmosfera umidificada de 5% de CO2 a 37°C até chegar a uma confluência de 90%. As culturas de células foram expostas ao NPS na concentração de 10μM durante seis horas. Nesta concentração de NPS e tempo de exposição ocorre uma taxa de mortalidade celular >90%. O guaraná diluído em água foi adicionado em cinco diferentes concentrações (0,5, 1, 5, 10 e 20 mg/mL). Os ensaios de viabilidade MTT e azul de tripan, de marcadores bioquímicos de estresse oxidativo e genotoxicidade (ensaio cometa) foram realizados. Adicionalmente, o estresse oxidativo celular foi avaliado através do ensaio da fluorescência do diacetato de 2,7 diclorofluoresceína (DCFDA) via microscopia confocal. O guaraná reverteu à toxicidade induzida pelo NPS principalmente em concentrações mais baixas (<5mg/mL), diminuindo a: mortalidade celular, peroxidação lipídica, dano de DNA e produção de espécies reativas a aumentou os níveis da enzima Super Óxido Dismutase (SOD). Entretanto, o guaraná não conseguiu reverter a inibição da catalase provavelmente desencadeada pela presença de cianeto que também são produzidos na decomposição do NPS. Os resultados sugerem que o guaraná tem efeitos na modulação das quantidades excessivas de NO provavelmente através de suas propriedades antioxidantes. Estes resultados confirmaram estudos prévios que sugerem que o guaraná tem efeito protetor contra morbidades como obesidade e síndrome metabólica que são relacionadas ao metabolismo.

O programa Coleta Seletiva Solidária, iniciado em 2003 pela Prefeitura de São Paulo e que prevê a realização da coleta seletiva domiciliar na cidade por meio de cooperativas de ex-catadores de materiais recicláveis subsidiadas pelo poder público, é sustentável em termos econômicos, sociais e ambientais? Embora a retórica em que se baseia esteja em sintonia com a matriz discursiva da sustentabilidade urbana - de uma forma geral e aplicada ao lixo - e com os preceitos da economia solidária, a iniciativa dispõe dos elementos e consegue alcançar os resultados que, na prática, podem garantir a sua manutenção como política pública? Para tentar responder essas duas perguntas, este trabalho se valeu da aplicação de indicadores de sustentabilidade para programas municipais de coleta seletiva em parceria com ex-catadores e para as organizações neles envolvidas, elaborados pelo grupo de trabalho Coselix, financiado pela Funasa (Fundação Nacional da Saúde). A partir dos resultados obtidos, e tendo como pano de fundo um referencial teórico que mostra como as políticas públicas ambientais devem buscar a mudança institucional para serem eficientes em seus propósitos de aproximar o ideal do desenvolvimento sustentável da realidade, chega-se à conclusão de que a Coleta Seletiva Solidária tem grau de sustentabilidade apenas médio, comprometido sobretudo por deficiências institucionais, que se refletem numa baixa eficiência socioambiental (baixa cobertura, média recuperação de materiais recicláveis e alto índice de rejeito) e no fato de as cooperativas que integram o programa também se mostrarem, via de regra, longe da sustentabilidade. Apesar disso, a iniciativa tem potencial, evidenciado principalmente por sua base legal clara, infra-estrutura bem montada e pelos ganhos sociais qualitativos obtidos em grande parte das cooperativas. / Is Coleta Seletiva Solidária, a municipal initiative which began in 2003 in the city of São Paulo and establishes that selective collection of household waste will be conducted by former scavengers organized in cooperatives, sustainable in economic, social and environmental terms? Although based in a rhetoric that seems in tunning with the discursive matrix of urban sustainability - in general and applied to waste issues -and with the concepts of solidary economy, does the project have the elements and can it achieve the results that, in practice, may grant its survival as a public policy? In an attempt to answer these questions, this dissertation turned to the application of sustainability indicators specially developed to analyze and rank municipal selective collection programs with former scavengers and the organizations involved in such initiatives, created by the work group Coselix, financed by Funasa (Fundação Nacional da Saúde). Based on the results obtained and having as framework theoretical references which point how environmental public policies must aim at institutional change in order to reach their goals and bring the sustainable development ideal closer to reality, it concludes that Coleta Seletiva Solidária has only a medium sustainability degree, compromised mainly by institutional flaws, that are reflected in a lack of socioenvironmental efficiency (small coverage, medium recovery of recyclable goods and high reject rate) and in the fact that the cooperatives involved in the program are, in general, also far from sustainability. However, the initiative shows potential especially when it comes to its legal base, to a well constructed infrastructure and to the qualitative social gains obtained in most of the cooperatives.

La dynamique co-évolutive qui joue dans les systèmes hôte-parasite conduit à une véritable course aux armements entre les deux protagonistes qui se traduit, dans certaines interactions comme celle qui est traitée dans cette thèse, par un polymorphisme de compatibilité dont les bases moléculaires sont méconnues. L'objectif de cette thèse était de progresser dans la connaissance des mécanismes moléculaires sous-jacents à ce polymorphisme de compatibilité dans l'interaction Biomphalaria glabrata/Schistosoma mansoni. Une approche protéomique comparative entre des souches de parasites compatibles et incompatibles nous a permis d'identifier des déterminants moléculaires clés de l'interaction exprimés par le parasite. Il s'agit d'une part de mucines hautement polymorphes potentiellement antigéniques, les "Schistosoma mansoni Polymorphic Mucin" (SmPoMucs), et d'autre part de molécules anti-oxydantes ("ROS scavengers"). Afin d'aborder la question de la course aux armements de manière complète, nous avons également recherché la "contre-partie moléculaire" exprimée par le mollusque et susceptible d'exprimer ce polymorphisme de compatibilité. Dans ce but, des approches de co-précipitation ont été menées. Elles ont permis de montrer que les SmPoMucs interagissaient avec des récepteurs immunitaires diversifiés du mollusque, les Fibrinogen-related Proteins (FREPs). Nous montrons ainsi pour la première fois dans une interaction parasite/hôte invertébré l'intervention d'un "système de type antigène-anticorps" impliquant un répertoire individuel polymorphe d'antigènes potentiels du parasite (les SmPoMucs) et un répertoire individuel diversifié de récepteurs immunitaires de son hôte (les FREPs). Nous avons également montré que le complexe immun formé par les deux dernières molécules citées incluait un troisième partenaire, une thioester-containing protein (TEP) qui appartient à une classe de molécules connue pour son rôle dans la fagocytose ou l'encapsulation. La présence de ce troisième partenaire au sein d'un même complexe renforce le rôle potentiellement immunitaire de ce complexe dans la reconnaissance et l'élimination du parasite. Au travers de cette thèse, nous nous sommes également intéressés à la course aux armements jouant sur les mécanismes effecteurs de l'immunité du mollusque. Dans notre modèle, les effecteurs responsables de la destruction du parasite sont principalement des espèces réactives de l'oxygène (ROS). Dans ce cas aussi, nous avons montré qu'il existe une concordance phénotypique entre la production de ROS par l'hôte et le niveau de "ROS scavengers" produits par le parasite pour contrecarrer la réaction de l'hôte. Ainsi, les mécanismes moléculaires responsables du polymorphisme de compatibilité dans l'interaction B. glabrata/S. mansoni s'appuieraient au moins sur deux facteurs d'une part sur la confrontation de répertoires de molécules polymorphes et/ou diversifiées en ce qui concerne les mécanismes de reconnaissance immunitaire, et d'autre part sur une adaptation réciproque quantitative en ce qui concerne certains mécanismes effecteurs de l'immunité.

Reactive oxygen species (ROS) such as superoxide radical anion (O2•¯), hydroxylradical (OH•), hydrogen peroxide (H2O2) and peroxynitrite (ONOO-) that are produced during the metabolism of oxygen under oxidative stress in aerobic organisms destroy several key biomolecules and lead to a number of disease states. Mammalian systems possess several effective defense mechanisms including antioxidant enzymes to detoxify these ROS. The selenocysteine-containing Glutathione peroxidase (GPx) is particularly an efficient enzyme in the detoxification of H2O2 and other hydroperoxides by using glutathione (GSH) as cofactor. The chemistry at the active siteof GPx has been extensively investigated with the help of synthetic selenium compounds. Although the anti-inflammatory compound ebselen(2-phenyl-1,2-benzoisoselenazol-3(2H)-one) is undergoing phase III clinical trial as antioxidant, the chemistry of ebselen is still not understood. The present study on a number of ebselen derivatives with various N-substitutions reveals that the substitution at the N atom is important for the antioxidant activity. This study also suggests that the nature for thiol cofactor has a dramatic effect on the GPx activity of ebselen derivatives. It has been shown that ebselen exhibits very poor catalytic activity in the presence of aromatic thiols mainly due to strong Se….O nonbonded interactions that lead to extensive thiol exchange reactions in the selenenyl sulfide intermediate. To prevent the se….O interactions, a series of tertiary amide-based diselenides have been synthesized along with their secondary amide counterparts. Detailed structure-activity correlation studies reveal that the GPx-like activity of the sec-amide-based compounds can be significantly enhanced by the substitution at the free-NH group of sec-amide functionality. The N,N-dialkylbenzylamine-based diselenides exhibit their catalytic activities via the generation of selenols which was confirmed by the reaction with anti-arthritic gold(I) compounds. Interestingly, the replacement of the hydrogen atom at the 6th position of the benzene ring of N,N-dialkylbenzylamine-based diselenides by a methoxy group prevents the thiol exchange reactions mainly be weakening the Se…N interactions and thus enhances the GPx activity. On the other hand, the catalytic activity of the tert-amine-based diselenides can also be increased by replacing the tert-amino groups with the corresponding sec-amine moieties. It has been observed that the basic amino group in the amine-based diselenides deprotonates the selenol and also the thiol cofactor, which is crucial for the higher catalytic activities of the amine-based compounds. Peroxynitrite (PN, ONOO), a strong nitrating agent, is known to inactivate a number of proteins, enzymes and other biomolecules by nitration of tyrosine residues. In this study, we have shown that the commonly used antithyroid drugs and their analogues inhibit protein tyrosine nitration. This study reveals that antithyroid agents having PN scavenging activity may be beneficial of hyperthyroidism as these compounds may protect the thyroid gland from nitrative or nitrosative stress.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-06-01T18:28:12Z No. of bitstreams: 1 SANTOS_Fabio_2017.pdf: 67920851 bytes, checksum: 05c272202a619adfb95c8590ddcb3c04 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-06-01T18:29:40Z (GMT) No. of bitstreams: 1 SANTOS_Fabio_2017.pdf: 67920851 bytes, checksum: 05c272202a619adfb95c8590ddcb3c04 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-06-01T18:29:49Z (GMT) No. of bitstreams: 1 SANTOS_Fabio_2017.pdf: 67920851 bytes, checksum: 05c272202a619adfb95c8590ddcb3c04 (MD5) / Made available in DSpace on 2017-06-01T18:29:57Z (GMT). No. of bitstreams: 1 SANTOS_Fabio_2017.pdf: 67920851 bytes, checksum: 05c272202a619adfb95c8590ddcb3c04 (MD5) Previous issue date: 2017-03-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Waste generation is a global challenge to be faced, especially in industrializing countries such as Brazil, where high waste generation in line with structural problems and inadequate waste management can result in environmental, economic and social problems. Thus, recycling can be considered as an important strategy to face this challenge in order to develop practices focused on the triple bottom line (sustainability). The recycling chain in Brazil is considered complex involving multiple actors, among them we can highlight the activities of scavengers as fundamental agents on viability of recycling. However, the scavengers are not always recognized, they are the ones that benefit least in the chain and they face several difficulties. In seeking to overcome the difficulties and achieve better positioning in the chain, scavengers have organized into cooperatives, networks and materials processing centers. From the environmental point of view, recycling processes, especially of post-consumer plastics, can also have an impact on the environment, if management is not established from the collection until the final disposal of the same. It is therefore important to adopt environmental management tools such as Cleaner Production (CP), for example, that result in benefits to the environment, society and organizations. This research aimed to identify opportunities for improvement in plastics recycling process in a cooperative of Sorocaba-SP, through the use of the CP tool. The research consisted of a case study in a cooperative that performs the recycling process of Polyethylene (PE) and Polypropylene (PP), transforming them into flakes and / or pellets. The steps of the CP adopted in this research were based on the Centro Nacional de Tecnologias Limpas (CNTL, 2003) and complemented by SEBRAE guidelines (2005) and by the study of Silva et al. (2013). The following steps were carried out: awareness and general characterization of the cooperative, mapping of the recycling process, quantification of input and output streams, definition of indicators, selection of the evaluation focus, identification of causes of waste generation, effluents and emissions, and identification of CP opportunities. The study revealed that the recycling process of the cooperative is passive to generate environmental impacts, mainly due to the lack of standardization of the raw material and the high consumption of water in the washing stage and consequent generation of effluents. 25 improvement opportunities were identified, focusing mainly on level 1 of housekeeping. In addition, barriers to CP in the cooperative were identified, especially those related to financial issues and lack of government support. Thus, it is necessary to overcome these barriers to an effective implementation of the CP and obtain the consequent economic, environmental and social benefits. / A geração de resíduos é um desafio mundial a ser enfrentado, principalmente nos países em processo de industrialização como o Brasil, no qual a alta geração de resíduos alinhada aos problemas estruturais de gestão e descartes inadequados podem ocasionar problemas ambientais, econômicos e sociais. Assim, a reciclagem pode ser considerada como uma importante estratégia para se enfrentar este desafio com o objetivo de desenvolver práticas voltadas para o tripé da sustentabilidade. A cadeia de reciclagem no Brasil é considerada complexa por envolver múltiplos atores, dentre eles, podem-se destacar a atuação dos catadores como agentes fundamentais na viabilização da reciclagem. No entanto, os catadores nem sempre são reconhecidos, são os que menos se beneficiam na cadeia e enfrentam várias dificuldades. Na busca por superar as dificuldades e obter um melhor posicionamento na cadeia, os catadores têm-se organizado em cooperativas, redes e centros de processamento de materiais. Sob o ponto de vista ambiental, os processos de reciclagem, principalmente dos plásticos oriundos do pós-consumo, também podem ocasionar impactos ao meio ambiente, caso não se estabeleça uma gestão desde a coleta até a destinação final dos mesmos. Assim, é importante a adoção de ferramentas de gestão ambiental como a Produção Mais Limpa (P+L), por exemplo, que resulte em benefícios ao meio ambiente, a sociedade e as organizações. Esta pesquisa objetivou identificar oportunidades de melhorias no processo de reciclagem dos plásticos em uma cooperativa de Sorocaba – SP, por meio da utilização da ferramenta P+L. A pesquisa consistiu em um estudo de caso em uma cooperativa que realiza o processo de reciclagem do Polietileno (PE) e Polipropileno (PP), transformando-os em flakes (fragmentos) e/ou pellets (grânulos). As etapas da P+L adotadas nesta pesquisa foram baseadas no Centro Nacional de Tecnologias Limpas (CNTL, 2003) e complementada pelas orientações do SEBRAE (2005) e pelo estudo de Silva et al. (2013). Assim realizaram-se as seguintes etapas: sensibilização e caracterização geral da cooperativa, mapeamento do processo de reciclagem, quantificação das correntes de entradas e saídas, definição de indicadores, seleção do foco de avaliação, identificação das causas de geração de resíduos, efluentes e emissões, e identificação de oportunidades de P+L. O estudo revelou que o processo de reciclagem da cooperativa é passivo de gerar impactos ambientais, devido principalmente a ausência de padronização da matéria-prima e o alto consumo de água na etapa de lavagem e consequente geração de efluentes. Foram identificadas 26 oportunidades de melhorias, em sua maioria classificadas no nível 1 da P+L (housekeeping). Além disso, foram identificadas barreiras de P+L na cooperativa, principalmente as relacionadas às questões financeiras e ausência de apoio governamental. Assim, foi constatado a necessidade de superar essas barreiras para uma efetiva implementação da P+L e obter os consequentes benefícios econômicos, ambientais e sociais.

Made available in DSpace on 2015-05-07T14:27:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1099940 bytes, checksum: 4201d6b375ef5db9b6cdd65ed74e0fd5 (MD5) Previous issue date: 2014-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Study of the concepts, goals, deadlines and relevant instruments to Law 12.305 of 2010 that establishes the National Policy of Solid Waste ( PNRS ) in Brazil and its application, considering the challenges to consolidate a new reality of sustainable growth from the production of less waste, either in the manufacturing process or even in domestic consumption , extending the life cycle of products and allowing the country to definitely assume a sustainable development agenda. Assuming that the implementation of this Public Environmental Policy can mean the realization of new paradigms of development with sustainability as advocates Agenda 21, it has been sought beneath the perspective of economic law to highlight the legal implications from the concepts of the State of Social Welfare and Sustainable Development in Brazil. The legislation analysis indicates the importance of the principles of precaution and prevention within the framework of legal protection and the sharing of responsibilities in environmental management. Taking as parameter the management and implementation of PNRS in João Pessoa -PB and the experience in Brazil of selective collection with scavengers of recycled material. The local collection program and the challenges to have a sustainable collection program has been described, which facilitates the full operation of the reverse logistics and selective collection systems with social and economic inclusion of the scavengers of recycled material and the application of sectoral agreements and responsability pos - demand, causing a change in patterns of production and consumption . / Estudo dos conceitos, metas, prazos e instrumentos pertinentes a Lei 12.305 de 2010 que institui a Política Nacional de Resíduos Sólidos (PNRS) no Brasil e da sua aplicação considerando os desafios para consolidar uma nova realidade de crescimento sustentável a partir da produção de menos resíduos, seja no processo industrial ou mesmo no consumo doméstico, ampliando o ciclo de vida dos produtos e permitindo ao país assumir definitivamente uma agenda de desenvolvimento sustentável. Partindo da premissa que a implantação dessa Política Pública Ambiental pode significar a concretização de novos paradigmas de desenvolvimento com sustentabilidade como preconiza a Agenda 21 , buscou-se sob a ótica do Direito Econômico destacar as implicações jurídicas a partir dos conceitos do Estado de Bem Estar Social e de Desenvolvimento Sustentável no Brasil. A análise da legislação indica a importância dos princípios da precaução e da prevenção no âmbito da proteção jurídica e do compartilhamento de responsabilidades na gestão ambiental. Tomando como parâmetro a gestão e aplicação da PNRS no município de João Pessoa-PB e a experiência no Brasil da coleta seletiva com os catadores de material reciclado. Descrito o programa local de coleta e os desafios para um programa de coleta sustentável, que viabilize o pleno funcionamento dos sistemas de logística reversa e coleta seletiva com a inclusão socioeconômica dos catadores de materiais recicláveis e a aplicação dos acordos setoriais e da responsabilidade pós-consumo, provocando uma mudança nos padrões de produção e consumo.

Made available in DSpace on 2017-07-10T18:33:41Z (GMT). No. of bitstreams: 1 Shirla P W Sterchile.pdf: 11138646 bytes, checksum: e053b8b68775a319c8e10fb81d1f61be (MD5) Previous issue date: 2009-07-28 / This project is constitutive of our professional practice as a social worker and of the formation process like mastering in the program of masters degree in Regional and Agrobusiness development. In this process we chose as the locus of this investigation the cooperative of the environmental agents from Santa Helena Friends of the Environment that the priory was seemed so common and known. We delimitaded as object the investigation the way of existing and being of the cooperative of environmental agents from Santa Helena Friends of the Environment and its imbrication at the Usine of improvement of solid waste from the borough of Santa Helena PR. Faced with the anxieties that guided the construction of the object here burst, forming from the initial contact in 2004 with the human scavengers of recycling materials from the borough of Santa Helena, We built up as the research problem: Do the innovators mechanism of theoretical and practical formulation present at the cooperative of the environmental agents from Santa Helena Friends of the Environment answer to the interests of the workers? . Watching the unhappiness of some human scavengers and the incentive of the municipal manager to the installation of the Usine and the formation of the Cooperative, allied with the postulates of capitalism, specially in its tarty phase we disbuilt and rebuilt the reality given from the research empiric. With this purpose, we define as the general aim: learn, understand and analyze the cooperative of work in the process of improvement of solid waste, in its concrete demonstration into the moviment of tardy capital in answers to the private determinations of the Capitalism in Brazil and its objectivation in the borough of Santa Helena. In base with boarding qualitative, having the case of study as the specific type of delimitation of the object and with the use of the bibliographic search, from the interview, of the documental analyze and of the observation, the search revealed the locus of this analyse. The investigated attitude allowed us to conclude that the Cooperative Friends of the Environment is treated of one cooperfradude , in which it is legitimized by the State, oblitarating the principles of the cooperativism and liberating the capital of the root of the exploration of the work power. The Cooperative mask the logical of the salaried, if acquitting the warranty of the rights socialy achieved by the workers, in whici they degraded in everyday fight throughout their survival. / Este trabalho é constitutivo do nosso exercício profissional como Assistente Social e do processo de formação como mestranda no Programa de Mestrado em Desenvolvimento Regional e Agronegócio. Neste processo, elegemos como lócus desta investigação a Cooperativa dos Agentes Ambientais de Santa Helena Amigos do Meio Ambiente que, a priori, nos parecia tão comum e conhecido. Delimitamos como objeto de análise A forma de existir e de ser da Cooperativa dos Agentes Ambientais de Santa Helena Amigos do Meio Ambiente e sua imbricação na Usina de Beneficiamento de Resíduos Sólidos do município de Santa Helena-PR. . Diante das angústias que nortearam a construção do objeto aqui deflagrado, que se formaram a partir do contato inicial em 2004 com os catadores de materiais recicláveis do município de Santa Helena-PR, construímos como problema de pesquisa: Os inovadores mecanismos de formulação teórica e prática presentes na Cooperativa dos Agentes Ambientais de Santa Helena Amigos do Meio Ambiente respondem aos interesses dos trabalhadores? . Observando o descontentamento de alguns catadores e o incentivo do gestor municipal para a instalação da Usina e a formação da Cooperativa, aliado aos postulados do capitalismo, principalmente em sua fase tardia, entendemos relevante desconstruir e reconstruir esta realidade a partir da pesquisa empírica. Com este propósito, definimos como objetivo Apreender, compreender e analisar a cooperativa de trabalho no processo de beneficiamento de resíduos sólidos, em sua manifestação concreta no movimento do capital tardio em resposta as determinações particulares do capitalismo no Brasil e sua objetivação no município de Santa Helena . Com base na abordagem qualitativa, tendo o estudo de caso como tipo específico de delimitação do objeto e com a utilização da pesquisa bibliográfica, da entrevista, da análise documental e da observação, a pesquisa desvelou o lócus desta análise. A atitude investigativa nos permitiu concluir que a Cooperativa Amigos do Meio Ambiente trata-se de uma cooperfradude , a qual é legitimada pelo Estado, suprimindo os princípios do cooperativismo e eximindo o capital da raiz da exploração da força de trabalho. A Cooperativa mascara a lógica do assalariamento, se isentando da garantia de direitos socialmente conquistados pelos trabalhadores, os quais se degradam na luta cotidiana pela sobrevivência.

Les diodes électroluminescentes organiques (OLED) ont une durée de vie limitée. Cette limitation est notamment due à la présence d'impuretés dans le matériau électroluminescent. Ces impuretés proviennent principalement des électrodes. Nous pensons que l'ajout de couches de matériaux entre les électrodes et le matériau électroluminescent peut retarder l'arrivée des impuretés. Cette couche ajoutée doit avoir plusieurs caractéristiques dont principalement :être conductrice, ne pas absorber la lumière, être facilement mise en oeuvre et être d'une grande pureté. Nous pensons que des matériaux de type discotique possédant une mésophase aux températures d'utilisation de la OLED peuvent remplir ce cahier des charges.<p>Nous avons choisi d'étudier les composés discotiques à base de triphénylène, car celui-ci n'absorbe pas dans le visible. Nous avons tout d'abord étudié les 2,3,6,7,10,11-Hexa-(alkylthio)triphénylènes (HATT). Les HATT possèdent déjà les propriétés physiques que nous recherchons à l'exception des propriétés thermotropes. Nous avons donc étudié la possibilité de modifier celles-ci.<p>La synthèse de plusieurs HATT possédant six chaînes alkylsulfanyles identiques n'a pas donné les résultats attendus du point de vue des propriétés thermotropes. Nous avons alors synthétisé des molécules possédant plusieurs chaînes alkylsulfanyles différentes. Après différents essais, nous avons trouvé un mélange de molécules possédant plusieurs chaînes latérales différentes ayant les propriétés physiques recherchées. Mais ce matériau est composé d'un grand nombre de molécules et sa purification est difficile. Les techniques classiques de purification des composés organiques ne donnant pas une pureté suffisante, ou étant inapplicables sur une mésophase cristal liquide à température ambiante, nous avons donc recherché d'autres techniques de purification ou d'obtention des propriétés thermotropes désirées.<p> Nous avons étudié la purification par raffinage de zone des matériaux à l'aide d'une impureté que nous avons ajoutée et suivie au cours des manipulations. Le raffinage de zone montre une bonne purification lors de l'utilisation d'une transition de phase entre une phase cristalline et une phase liquide. Par contre, lors de l'utilisation d'une transition impliquant une mésophase (cristal liquide ou cristal plastique), une faible (ou une absence de) purification est observée. Ces deux dernières études ont été faites sur des 2,3,6,7,10,11-Hexa(alkyloxy)triphénylènes (HAOT) que nous avons synthétisés et purifiés au préalable. <p>Les gels de silice fonctionnalisés que nous avons utilisés montrent une purification des cations métalliques durs et, dans une moindre mesure, des cations métalliques intermédiaires dans le concept dur-mou. Le phosphore, seul élément non-métallique que nous ayons étudié, est l'élément dont la baisse de concentration est la moins efficace.<p>La seconde approche pour obtenir des mélanges possédant une mésophase cristal liquide à température ambiante est la formation de mélanges de molécules synthétisées et purifiées isolément. Parmi les mélanges de molécules que nous avons effectués, nous avons pu observer une plage de concentration de mélanges ternaires qui possède les propriétés thermotropes recherchées.<p>Nous avons donc obtenu un matériau cristal liquide à température ambiante grâce à un mélange de molécules. Le matériau ainsi formé absorbe peu dans le visible, possède potentiellement une bonne mobilité des porteurs de charges électriques, est facilement obtenu à une pureté suffisante. Ce mélange de molécules possède donc les propriétés que nous recherchons pour être utilisé comme couche de matériau ajoutée aux OLED.<p> / Doctorat en sciences, Spécialisation chimie / info:eu-repo/semantics/nonPublished

Fuel cells are known for their high efficiency and have the potential to become a major technology for producing clean energy, especially when the fuel, e.g. hydrogen, is produced from renewable energy sources such as wind or solar. Currently, the two main obstacles to wide-spread commercialization are their high cost and the short operational lifetime of certain components. Polymer electrolyte membrane (PEM) fuel cells have been a focus of attention in recent years, due to their use of hydrogen as a fuel, their comparatively low operating temperature and flexibility for use in both stationary and portable (automotive) applications. Perfluorosulfonic acid membranes are the leading ionomers for use in PEM hydrogen fuel cells. They combine essential qualities, such as high mechanical and thermal stability, with high proton conductivity. However, they are expensive and currently show insufficient chemical stability towards radicals formed during fuel cell operation, resulting in degradation that leads to premature failure. The incorporation of durability improving additives into perfluorosulfonic acid membranes is discussed in this work. iv Cerium oxide (ceria) is a well-known radical scavenger that has been used in the biological and medical field. It is able to quench radicals by facilely switching between its Ce(III) and Ce(IV) oxidation states. In this work, cerium oxide nanoparticles were added to perfluorosulfonic acid membranes and subjected to ex-situ and in-situ accelerated durability tests. The two ceria formulations, an in-house synthesized and commercially available material, were found to consist of crystalline particles of 2 – 5 nm and 20 – 150 nm size, respectively, that did not change size or shape when incorporated into the membranes. At higher temperature and relative humidity in gas flowing conditions, ceria in membranes is found to be reduced to its ionic form by virtue of the acidic environment. In ex-situ Fenton testing, the inclusion of ceria into membranes reduced the emission of fluoride, a strong indicator of degradation, by an order of magnitude with both liquid and gaseous hydrogen peroxide. In open-circuit voltage (OCV) hold fuel cell testing, ceria improved durability, as measured by several parameters such as OCV decay rate, fluoride emission and cell performance, over several hundred hours and influenced the formation of the platinum band typically found after durability testing.

<p>&Scaron;tavelj (Rumex crispus, Polygonaceae) je vi&scaron;egodi&scaron;nja zeljasta biljka, koja predstavlja bogat izvor fenolnih komponenti. Iako se smatra invazivnim korovom, mlado li&scaron;će &scaron;tavelja je jestivo i često se koristi kao salata. Dalje, upotreba plodova &scaron;tavelja opisana je u srpskoj i turskoj narodnoj medicini u lečenju gastrointestinalnih tegoba. Cilj ovog rada bio je procena in vitro i in vivo antioksidantne/prooksidantne i citotoksične aktivnosti, i određivanje eventualnog in vitro antiinflamatornog efekta vodenog ekstrakta ploda Rumex crispus. Ukupan sadržaj flavonoida određen je spektrofotometrijskom metodom. Kvalifikacija i kvantifikacija flavonoida potvrđena je visokoefikasnom tečnom hromatografijom (HPLC). Antioksidantna aktivnost vodenog ekstrakta ploda &scaron;tavelja procenjena je na osnovu in vitro testova: Ferric-reducing antioxidant power (FRAP), sposobnosti ekstrakta da neutrali&scaron;e slobodne radikale NO&bull;, OH&bull; i DPPH&bull; i uticaja na lipidnu peroksidaciju u lipozomima. Citotoksičnost ispitivanog ekstrakta je određena in vitro na tumorskim ćelijskim linijama: humani karcinom cerviksa (HeLa), adenokarcinom (HT-29) i adenokarcinom dojke (MCF7). Takođe, moguća in vivo hepatoprotektivna i antioksidantna svojstva ekstrakta određena su kod oksidativnog stresa izazvanog CCl4 kod eksperimentalnih životinja. Pored toga, proverena je hipoteza u kojoj testiran ekstrakt pokazuje in vivo antiproliferativnu aktivnost kod Ehrlich-ovih (EAC) i Hepatoma AS30D ćelija, merenjem zapremine ascitesa, procenta vijabilnih ćelija i nivoa nekoliko antioksidantnih enzima. Optimizovan in vitro test za određivanje potencijala inhibicije ciklooksigenaze-1 (COX-1) i 12-lipooksigenaze (12-LOX) preduzet je u svrhu procene antiinflamatornog efekta vodenog ekstrakta ploda R. crispus. HPLC analiza otkrila je da je mikvelianin najdominantniji flavonoidni konstituent ekstrakta. Testirani ekstrakt pokazao je potencijalnu antioksidantnu aktivnost rezultujući velikom moći u neutralizaciji slobodnih radikala, i sposobno&scaron;ću da smanji lipidnu peroksidaciju u lipozomima. Rezultati su ukazali na tkivno-selektivnu citotoksičnost ekstrakta ploda R. crispus in vitro. Najizraženija antitumorska aktivnost primećena je prema HeLa i MCF7 ćelijskim linijama. Podaci sugeri&scaron;u da bi se ispitivani ekstrakt mogao smatrati potencijalnim in vivo hepatoprotektivnim i antioksidantnim agensom, sprečavajući oksidativna o&scaron;tećenja jetre. S druge strane, pomenuti ekstrakt može pokazati in vivo prooksidantna svojstva, uzrokujući oksidativni stres u maligno transformisanim EAC i AS30D ćelijama i smanjujući zapreminu ascitesa i udeo vijabilnih ćelija, u poređenju sa kontrolnom grupom. Promene u aktivnosti antioksidantnih enzima su verovatno posledica indukovanog oksidativnog stresa u EAC i AS30D ćelijama, naročito kod pretretiranih životinja. Vodeni ekstrakt ploda &scaron;tavelja pokazao je COX-1, kao i 12-LOX inhibitornu aktivnost, navodeći da bi ispitivani ekstrakt mogao biti antiinflamatorni agens. Vodeni ekstrakt ploda R. crispus ima potencijalnu antioksidantnu, citotoksičnu i antiinflamatornu aktivnost. Ispoljavanje prooksidantnih svojstava predstavlja mogući mehanizam antiproliferativnog efekta ekstrakta.</p> / <p>Curly dock (Rumex crispus, Polygonaceae) is a wild perennial herbaceous plant, which products are described as a rich source of phenolic compounds. Apart from being considered a seriously invasive weed, young leaves of curly dock are edible and often used as salad. Furthermore, the use of its fruits has been described in Serbian and Turkish traditional medicine against stomach complaints. The objectives of this study were to evaluate in vitro and in vivo antioxidant/prooxidant and cytotoxic activities, and to determine an eventual in vitro anti-inflammatory effect of the aqueous extract of Rumex crispus fruits. Total flavonoid content was determined by spectrophotometric method. Qualification and quantification of flavonoids were confirmed using High performance liquid chromatography (HPLC). The aqueous extract of curly dock fruits was evaluated for its antioxidant activity by in vitro assays for Ferric-reducing antioxidant power (FRAP), NO&bull;, OH&bull; and DPPH&bull;-free radical scavenging activities and the influence on lipid peroxidation in liposomes. The cytotoxicity of tested extract was examined in vitro in human cervix carcinoma (HeLa), colon adenocarcinoma (HT-29) and breast adenocarcinoma (MCF7). Also, the potential in vivo hepatoprotective and antioxidant properties of investigated extract were determined on CCl4-induced oxidative stress in experimental animals. Furthermore, the hypothesis that the examined extract might show in vivo antiproliferative activity in Ehrlich carcinoma (EAC) and Hepatoma AS30D cells was tested by measuring volume of ascites, percentage of viable cells and level of several antioxidant enzymes. The optimized in vitro test for determination of cyclooxygenase-1 (COX-1) and 12-lipoxygenase (12-LOX) inhibition potency was undertaken in order to estimate an anti-inflammatory effect of aqueous extract of R. crispus fruits. HPLC analysis revealed miquelianin as the most abundant flavonoid constituent of the extract. The tested extract might have an antioxidant activity resulting in scavenging of free radicals and ability to decrease lipid peroxidation in liposomes. The results could indicate tissue-selective cytotoxicity of R. crispus fruit extract in vitro. The most prominent antitumor activity was observed towards HeLa and MCF7 cell lines. The data suggested that investigated extract may be considered as potential in vivo hepatoprotective and antioxidant agent due to prevention of the liver injuries induced by oxidative damage. On the other hand, mentioned extract could exhibit in vivo prooxidant property, causing the oxidative stress in malignant transformed EAC and AS30D cells and reducing volume of ascites and percentage of viable cells, in comparison with control group. Changes in activities of antioxidant enzymes might be the results of induced oxidative stress in EAC and AS30D cells, especially in the pretreated animals. The aqueous extract of curly dock fruits showed COX-1, as well as 12-LOX inhibitory activity, suggesting that tested extract might be an anti-inflammatory agent. It could be concluded that aqueous fruit extract of R. crispus might have antioxidant, cytotoxic and anti-inflammatory activities. The prooxidant properties of examined extract could be the mechanism of potential antiproliferative effect of extract.</p>