• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2894
  • 996
  • 609
  • 487
  • 177
  • 176
  • 127
  • 102
  • 84
  • 72
  • 58
  • 52
  • 48
  • 42
  • 19
  • Tagged with
  • 6835
  • 557
  • 515
  • 491
  • 476
  • 407
  • 402
  • 347
  • 337
  • 323
  • 303
  • 301
  • 297
  • 242
  • 233
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
501

Cinética de expressão de moléculas co-estimulatórias de osteoclastos no desenvolvimento da doença periodontal experimental e sua modulação por citocinas / Kinetics of osteoclast co-stimulatory molecules throughout experimental periodontitis and mice and its modulation by cytokines

Repeke, Carlos Eduardo Palanch 03 October 2012 (has links)
O processo de diferenciação e ativação de osteoclastos, essencial para a manutenção da homeostasia do tecido ósseo e também envolvido na patogênese de diversas patologias caracterizadas pela atividade osteolítica, depende de um sistema central de controle que envolve a ligação das moléculas RANK/RANKL. Além do sistema RANK/RANKL, moléculas co-estimulatórias de osteoclastos, tais como os complexos DAP-12, TREM-2 e SIRP1, e FcR, OSCAR e PIR-A, também apresentam um papel importante na geração e ativação de osteoclastos. Entretanto, a possível contribuição de tais moléculas para a progressão da doença periodontal (DP) permanece desconhecida, assim como o possível impacto de citocinas na modulação de sua expressão no microambiente periodontal. Nosso objetivo foi investigar, por RealTimePCR, o padrão de expressão de moléculas co-estimulatórias de osteoclastos (DAP-12, TREM-2 e SIRP1, e FcR, OSCAR e PIR-A) na periodontite crônica em humanos, além de avaliar a cinética de expressão destas moléculas e a sua modulação por citocinas (TNF-, IFN-, IL-17 e IL-10) ao longo do curso da DP em camundongos em camundongos C57Bl/6 wild-type (WT) e geneticamente modificados (TNFp55KO, IFNKO, IL17KO, IL10KO. Nossos resultados demonstram que nas lesões periodontais crônicas a expressão de todas as moléculas co-estimulatórias de osteoclastos apresentaram-se significativamente aumentadas quando comparadas às amostras controle. Com relação à periodontite experimental, verificamos que todas as moléculas co-estimulatórias alvo apresentavam aumento em sua expressão após a indução de doença quando comparado aos controles. Nos camundongos para TNFp55KO, IFNKO e IL17KO, observamos uma redução na severidade da DP (reabsorção óssea e quantidade de células inflamatórias) e na expressão de moléculas co-estimulatórias, ao contrário do observado nos camundongos IL10KO. Entretanto, ao normalizarmos os níveis de expressão das moléculas co-estimulatórias de osteoclastos pelo número de células inflamatórias, verificamos que TNF- e IL-17 se mostram associados a uma maior expressão de moléculas co-estimulatórias, enquanto IFN- e IL-10 parecem regular negativamente a expressão de tais moléculas. Em termos gerais, demonstramos que a expressão de moléculas co-estimulatórias de osteoclastos se mostra aumentada na DP humana e experimental, e que citocinas parecem modular sua expressão por mecanismos diretos e indiretos, tais como a migração de células inflamatórias para os sítios de doença periodontal. / The osteoclast differentiation and activation are essential to bone tissue homeostasis and in the development of bone pathologies, which RANK/RANKL signaling molecules are the major osteoclastogenic factor. However, osteoclast co-stimulatory molecules, such as DAP-12, TREM-2, SIRP1, FcR, OSCAR and PIR-A, also present an important role in the osteoclastogenesis. However, the exact role and regulation of these molecules in human and mice periodontal diseases (PD) development have not completely known. Our aim was to investigate the pattern of osteoclast co-stimulatory expression (DAP-12, TREM-2, SIRP1, FcR, OSCAR and PIR-A) in human chronic periodontitis (CP), apart from analyze the kinetic of these molecules and their regulation by cytokines (TNF-, IFN-, IL-17 and IL-10) in the development of experimental periodontal disease in mice C57Bl/6 and knockout. Our results demonstrated that all osteoclast co-stimulatory molecules presented highly expressed in CP patients when compared with control. Similar results are presented about experimental PD, where all co-stimulatory molecules was presented highly expressed in infected mice when compared with control mice. We observed in TNFp55KO, IFNKO and IL17KO mice a decrease in PD scores and co-stimulatory molecules expression, the opposite of IL10KO mice. However, when we standardized the co-stimulatory molecules levels by the number of inflammatory cells, we found that TNF- and IL-17 are associated with increased expression of co-stimulatory molecules, while IFN- and IL-10 appear to negatively regulate the expression of such molecules. In conclusion, we demonstrated that osteoclast co-stimulatory molecules shown increased in human and experimental PD, and cytokines appear to modulate their expression by direct and indirect mechanisms, such as inflammatory cells migration to the PD infected tissue.
502

Redes sociais de colaboração acadêmica: tendências, determinantes e fricções do processo de formação de coautorias entre pesquisadores no Brasil / Social networks of academic collaboration: trends, determinants and frictions the of coauthorship formation process among researchers in Brazil.

Silva, Maximiliano Barbosa da 12 August 2013 (has links)
Nesta tese, estudam-se as tendências, os determinantes e as fricções do processo de formação de coautorias na produção de artigos acadêmicos entre pesquisadores no Brasil. Esta tarefa é dividida em três artigos. O primeiro artigo analisa a evolução temporal da incidência e da extensão de coautoria entre pesquisadores de diferentes campos do conhecimento. Os resultados obtidos confirmam a tendência, reportada na literatura, de crescimento do percentual de artigos coautorados e do número médio de autores por artigo. Em seguida, investigam-se os determinantes deste tipo de colaboração formal entre acadêmicos. Encontra-se que mulheres são mais propensas à coautoria do que homens, que trabalhos não puramente teóricos são mais propícios à colaboração e que a probabilidade de colaboração por parte de um pesquisador aumenta com o seu nível de dedicação em alguns campos do conhecimento. O segundo artigo estuda a evolução da rede social de coautoria em nove grandes áreas do conhecimento ao longo das últimas quatro décadas. Mostra-se que em quatro das nove grandes áreas do conhecimento analisadas, a rede social de coautoria pode ser considerada um mundo pequeno. Adicionalmente, ao decompor o processo de formação dos grafos de coautoria em seus componentes aleatórios e sociais, conclui-se que existem fricções significativas no pareamento de pesquisadores e que estas variam entre os campos do conhecimento, ao longo do tempo e entre populações de pesquisadores. O terceiro artigo investiga como a distância e o número de menores caminhos entre dois pesquisadores inseridos em uma rede social de coautoria afetam a probabilidade de que eles estabeleçam um elo de colaboração entre si. Oito grandes áreas do conhecimento são estudadas. Os resultados mostram que em quatro destes campos existem efeitos de proximidade em rede sobre a probabilidade de emergência de um novo link de coautoria e que estes efeitos são fortes. Além disto, a estratégia econométrica adotada permite concluir que estes efeitos decorrem do fluxo de informação sobre atributos individuais e qualidade de pareamentos passados através das redes de colaboração acadêmica. Além destas três contribuições principais, o capítulo introdutório desenvolve uma extensa revisão da literatura sobre redes econômicas e sociais com o objetivo de motivar o grande interesse da profissão pelo tema. / This dissertation studies the trends, determinants and frictions of the formation of coauthorship links among researchers in Brazil for the production of academic articles. This task is divided into three papers. The first paper studies the evolution over time of the incidence and extension of coauthorship among researchers in various fields of knowledge. The results confirm the trend of growth, reported in the literature, in the percentage of coauthored papers and in the average number of authors per paper. Next, the determinants of formal collaboration among academics are investigated. It is found that women are more inclined to collaborate than men, that non-purely theoretic papers are more collaboration prone and that the probability of collaboration is increasing with the number of hours devoted by an individual to research in some fields of knowledge. The second paper studies the evolution of the coauthorship network in nine broad fields of knowledge over the last four decades. It is shown that in four of the nine broad fields of knowledge analyzed, the coauthorship network can be considered a small world. In addition to that, by decomposing the network formation process into its random and social components, it can be concluded that there exist significant matching frictions among researchers and that they differ across fields, time and population. The third paper investigates how the distance and the number of shortest paths between two researchers in a coauthorship network affect the probability that they initiate a collaboration. Eight broad fields of knowledge are studied. The results show that in four of them there are social network proximity effects on the probability of the emergence of a new coauthorship link and that these effects are strong. Moreover, the econometric strategy permits to conclude that the effects result from the flow of information about individual attributes and about past matching quality through the links of the network of academic collaboration. In addition to these three main contributions, the introductory chapter presents an extensive review of the social and economic networks literature with the purpose of motivating the great interest on this subject.
503

\"Estudo da eletro-oxidação de monóxido de carbono sobre eletrocatalisadores suportados por espectroscopia de impedância eletroquímica\" / Study of carbon monoxide electro-oxidation on supported electrocatalysts by electrochemical impedance spectroscopy

Ciapina, Eduardo Gonçalves 16 February 2006 (has links)
O presente trabalho estudou comparativamente, do ponto de vista fundamental, a reação de eletro-oxidação de monóxido de carbono (CO) em meio ácido, sobre Pt75Sn25/C, Pt65Ru35/C e Pt/C através da Espectroscopia de Impedância Eletroquímica. Os materiais foram preparados por redução com ácido fórmico e caracterizados fisicamente por EDX e DRX de alta intensidade e eletroquimicamente por voltametria. Previamente aos estudos de Impedância, foram realizados estudos potenciodinâmicos da reação de eletro-oxidação de CO adsorvido (?Stripping de CO?) e a oxidação de CO em uma solução saturada de CO. Para os materiais Pt65Ru35/C e Pt/C, estes estudos mostraram que há um deslocamento de potencial do inicio da oxidação para valores mais positivos quando CO está presente em solução se comparado a oxidação (stripping) de CO, devido a competição de sítios de adsorção entre moléculas de CO e H2O, responsáveis pela reação. Por outro lado, no material bimetálico Pt75Sn25/C a presença de CO em solução não influenciou de maneira significativa o potencial de inicio da oxidação, confirmando a ausência de adsorção competitiva neste material. A curva de polarização em estado estacionário revelou que, dentre os 3 materiais estudados, o material bimetálico Pt75Sn25/C apresentou a maior atividade eletrocatalítica, isto é, maiores densidades de correntes em menores sobrepotenciais. Este comportamento foi, em grande parte, esclarecido através dos experimentos de Espectroscopia de Impedância Eletroquímica. Com a Espectroscopia de Impedância Eletroquímica foi verificada a formação de espécies oxigenadas em Pt/C e em Pt65Ru35/C no intervalo de freqüências estudado, enquanto que em Pt75Sn25/C os diagramas de impedância revelaram um comportamento predominantemente capacitivo, indicando a ausência de reações de transferência de carga devido à oxidação da H2O para formar hidróxidos/óxidos na superfície do material. Também foi demonstrado que os processos relacionados a reação entre COads e espécies oxigenadas superficiais são mais rápidos em Pt75Sn25/C do que em Pt/C e Pt65Ru35/C, como ficou evidente no diagrama de Bode do ângulo de fase em função da freqüência. Mais especificamente, a menor resistência de transferência de carga para a reação em Pt75Sn25/C aparece em freqüências mais altas provavelmente devido à reação ocorrer com espécies oxigenadas já presentes na fase SnO2 presente no material. Por outro lado, os processos de adsorção são mais rápidos devido a menor energia de adsorção de CO sobre Pt, de acordo com os resultados encontrados por cálculos teóricos de DFT. / In this work, kinetic aspects of CO electro-oxidation on Pt/C, Pt75Sn25/C and Pt65Ru35/C prepared by chemical reduction with formic acid were studied by Electrochemical Impedance Spectroscopy (EIS). The bulk composition of the asprepared PtSn/C and PtRu/C bimetallic materials, analyzed by EDX, was 77:23 and 64:36, respectively. Using high intensity XDR measurements the bulk structure and phase determinations could be established. The analysis of the XRD profiles of Pt75Sn25/C revealed partial alloy formation and the presence of a SnO2 phase. For Pt65Ru35/C, no alloy formation was verified. Potentiodynamic oxidation of CO in a CO-saturated solution compared with CO stripping voltammetry pointed out the presence of competitive adsorption between CO and oxygen containing species on the surface of Pt/C and Pt65Ru35/C while for Pt75Sn25/C no competition for surface sites was verified. Impedance measurements were conducted in two different conditions: i) in the absence of CO in solution and ii) in a CO saturated solution. Provided by an equivalent circuit the charge transfer resistance (Rct), was obtained for the studied materials. The mean double layer capacitance (Cdl) was also estimated from circuit parameters and revealed its dependence on the carbon monoxide surface coverage (_CO). Furthermore, the relation between the _CO and the charge transfer resistance for the reaction is discussed. Using EIS it was demonstrated that the Rct for the carbon monoxide electro-oxidation reaction on Pt75Sn25/C is much lower than on Pt/C and Pt65Ru35/C, which was related to the presence of oxygen-containing species already present in the SnO2 phase as well as to the faster adsorption processes on this material compared to Pt/C and Pt65Ru35/C.
504

Understanding participation and power within collaborative processes : jointly involving staff and citizens in changing public services

Farr, Michelle January 2012 (has links)
This study assesses the extent to which employees and users of public services can develop collaborative partnerships that promote person-centred services within institutions. Both citizen and worker participation are currently advocated as a means to develop public services, yet academically they have been studied within distinctive disciplines. Drawing together different theories of participation alongside the analysis of the concepts and practices of co-production, co-design and co-creation, this thesis establishes an analytic framework, termed co-participation to explore processes of collaboration between public service staff and users. This framework then informs the analysis of two case studies in local government and the health service where both staff and service users are involved together in developing person-centred services. This empirical work is supplemented by expert interviews with people who have worked in a number of different collaborative projects, alongside a realist synthesis of other similar cases. Using a critical realist approach and retroductive analysis this study explores how agents act within their institutional and policy contexts, assessing the extent to which their actions can instigate changes through institutionally designed participatory projects. It is found that the projects facilitated processes of reflexivity and intersubjectivity which promoted a sense of embedded collectivism within institutional contexts. The projects enabled agents to make many localised changes which positively impacted people’s lived experiences. Collectivities and networks were developed, yet these operated within dominant hierarchies and could be limited by their structural and cultural environments. Wider social inequalities and power relations had an impact upon these participatory processes, although participatory processes could also be adapted to enable greater access and more equal voice. These projects and practices are analysed within the wider context of the continuing neo-liberal reform of public services, exploring how the state shapes the structural and policy context which sets situational logics and conditions of possibility for these practices.
505

La parole pulvérisée : émergence et singularité d’une littérature de témoignage sur le génocide du Rwanda / The dramatic change in Rwandan expression : the newness and singularity of a "witness literature" about the Rwandan genocide

Talayssat, Anne-Sophie 19 June 2017 (has links)
Dès 1997, des témoins rwandais rescapés d'un des événements les plus sombres du XXème siècle ont témoigné de leur expérience au cœur du génocide Tutsi survenu trois ans auparavant. La nécessité de mettre en récit l’horreur traversée a fait naître, en langue française, une littérature d’« un genre nouveau » qui n’existait pas dans le pays. En analysant seize récits rwandais de témoins directs du génocide, la thèse discute l’obstacle présupposé de leur co-écriture et met en évidence l’émergence et la singularité de cette littérature de témoignage : sa naissance dans la déchirure ; son mode spécifique d’élaboration ; sa poéticité ; sa rhétorique de la pulvérisation inhérente au traumatisme et, spécificité remarquable dans une culture où l’expression du « moi » n’est guère encouragée, son hybridation entre témoignage et autobiographie. Au confluent de l’histoire personnelle et de l’Histoire collective, certains témoins rescapés ont en effet exploré la voie d’une narration intime afin de reconstruire ce que le génocide a fait voler en éclats : le rapport à soi-même et à une communauté qui, après les avoir niés en tant qu’êtres humains, a tardé à les reconnaître en tant que victimes. Ce projet testimonial constitue tout autant une tentative de résilience qu’une quête de justice, un acte conclusif du deuil et une difficile progression de la survie vers la vie. Cette thèse inscrit de plein droit dans la littérature des œuvres essentielles et irremplaçables pour approcher au plus près la vérité du traumatisme et des faits génocidaires endurés. / Since 1997 Rwandan witnesses who have survived the Tutsi genocide in Rwanda in 1994 have related their dreadful experience of one of the worst events of the 20th century. The urge to write about this terrible event was the starting point of a new genre of writing in French in the country. By analysing sixteen direct witnesses' accounts this thesis examines the assumption that the need to resort to another person to transcribe their oral testimonies could present an obstacle. It reveals the newness and singularity of this " witness literature " : a dramatic break from all traditional artistic forms, the specific technique with a note of poetry, the way it describes the devastation caused by the traumatic events. Moreover what is remarkable in a culture in which self- expression is not encouraged is how it combines testimony and autobiography. Indeed where personal history and collective history meet, by telling their private accounts some surviving witnesses have been able to rebuild what the genocide had destroyed, that is to say introspection and the relationship with the community which not only had not considered them as human beings but had also delayed recognising them as victims. This " testimony project" is an attempt at resilience and a demand for justice as well, a way of coming out of mourning in order to be able to go on living. This thesis intends to fully acknowledge the literary quality of these very important, essential writings and to understand the intensity of the trauma caused by the criminal acts they had to endure during the genocide.
506

La tétraspanine Co-029/tspan8 dans le cancer du côlon / The tetraspanin Co-029/tspan8 in colon cancer

Ailane, Naouel 23 November 2012 (has links)
Les tétraspanines sont des glycoprotéines membranaires impliquées dans une variété de processus physiologiques et pathologiques. En cancérologie, de nombreuses études cliniques et expérimentales ont établi un lien entre le niveau d’expression de certaines tétraspanines et la formation de métastases. Ce travail porte sur la tétraspanine Co-029/tpan8 et son rôle dans le processus métastatique dans le cancer du côlon. Afin d’appréhender ce rôle, un modèle cellulaire a été développé dans le laboratoire à partir de la lignée Isreco1 où nous avons surexprimé de manière stable le Co-029/tspan8. Sur ce modèle nous avons étudié dans un premier temps la migration cellulaire, élément capital participant à la genèse des métastases. Nous avons montré que le Co-029/tspan8 coordonne la motilité cellulaire en fonction de plusieurs signaux issus de la membrane (intégrines, complexe E-cadhérine/p120ctn, EGFR, MET). Par ailleurs, nous avons montré dans une première étude clinique que l'expression de Co-029/tspan8 dans la tumeur serait de pronostic péjoratif. Nous avons également montré que l’anticorps anti-Co029 (Ts29.2) produit dans notre laboratoire induit une réduction significative de la croissance tumorale in vivo dans la souris nude. Nos travaux suggèrent que Co-029/tspan8 serait à la fois un marqueur de pronostic et une cible potentielle pour l'utilisation thérapeutique des anticorps monoclonaux dans le cancer du côlon. / Tetraspanins are membrane glycoproteins involved in a variety of physiological and pathological processes. In cancerology, many clinical and experimental studies have established a link between expression’s level of some tetraspanins and metastasis. This work focuses on the tetraspanin Co-029/tspan8 and its implication in the metastatic process in colon carcinoma. We developed a cellular model from primary colon carcinoma cell line Isreco1 in which we stably overexpressed Co-029/tspan8. In this model we studied, first, cell migration, an essential process for metastasis formation. We have shown that Co-029/tspan8 coordinates cell motility according to several signals from the membrane (integrins, E-cadherin/p120ctn complex, EGFR, MET). Moreover, in a first clinical study the Co-029/tspan8 expression in primary tumors seems to correlate with poor prognosis. We also showed that the antibody anti-Co029 (Ts29.2) produced in our laboratory induced a significant inhibition of tumor growth in nude mice. Our study suggests Co-029/tspan8 as a marker of prognosis and a potential target for monoclonal antibody therapy in colon cancer.
507

Co-­‐branding i modevärlden -­‐ En studie i hur co-­‐branding påverkar ett modeföretags brand equity

Dahlin, Carl Johan, Andersson, Eleonor January 2013 (has links)
Syfte - Studien syftar till att undersöka hur ett modeföretags icke-finansiella(konsumentbaserade) brand equity påverkas av co-branding. Studien undersöker hur ettsamarbete mellan två modeföretag, så kallat intrabranschsamarbete, påverkar huvudvarumärketsicke-finansiella brand equity.Metod - Studien utgår från Aakers modell för att mäta brand equity. Metoden för studien harvarit att använda fokusgrupper för att undersöka konsumentattityder till co-branding. I studienanvändes ett verklighetsbaserat modesamarbete som diskussionsunderlag för fokusgrupperna,där ett fallföretag och dess samarbete med en annan modeaktör valdes ut. Totalt 12 styckenstudenter från Textilhögskolan i Borås deltog i studien, fördelat över två fokusgrupper.Fynd - Studien visar att ett modevarumärkes brand equity kan stärkas och påverkas positivt medhjälp av co-branding.Begränsningar - Uppsatsen är begränsad till ett samarbete genomfört av två textilföretag vilketgör resultaten främst applicerbara på samarbeten inom modebranschen. Fler genomförda studier,med ett större antal fokusgrupper och en bredare population, skulle kunna ökageneraliserbarheten.Originalitet - Studien undersöker konsumentattityder till co-branding inom modebranschen medhjälp av fokusgrupper. Resultatet ger empiriska indikationer på hur svenska studenter ser på cobrandinginom mode branschen och hur ett modeföretags brand equity påverkas av co-branding. / Program: Textilekonomutbildningen
508

Enacting change with renewable energy : a situational analysis of Udny's Community Turbine and Trust : towards an ecological sociology

Robertson, Laurie Lee January 2018 (has links)
Energy is part of everyday life and renewable energy technologies are increasingly becoming part of our lived environments. Social scientists are responding to renewable energy technologies by investigating what people think about wind turbines (Aitken, 2010; Pasqualetti, 2011a, 2011b) and the distribution of community benefits (Cowell et al, 2011; Bristow et al 2012). This thesis adds to this body of research by describing Udny's renewable energy project and its capacity to effect change. More specifically, I examine what this community-owned wind turbine does with other situational elements to transform life within the community. Using the cartographic methods developed by Adele E. Clarke (2005), I map out the situation by drawing out the elements – this includes objects, people, organisations and discursive practices – and tracing their relations. Thinking sociologically about situational elements and their relational effects provokes a move towards ecological sociology and re-imagines social life as the effect of interconnected entities, such as materials and meanings, thoughts and actions, people and objects (Morton, 2007, 2010). Mapping the interconnectedness of societal ecologies depicts social life as neither distinct from the natural world (Catton and Dunlap, 1978, 1980) nor symmetrical with natures (Callon, 1986; Akrich and Latour, 1992; Asdal, 2008) but, rather, as part of relationally emergent ecologies. Udny's community renewable energy project illustrates the relational emergence of a social ecology, as the turbine and trust work with existing and emergent entities to enact change (Barad, 2007; Harman, 2009; Bennett, 2010; Morton, 2010, 2016). It is by doing things together that situational elements transform life within Udny (Clarke, 2005; Yusoff, 2013).
509

Análise epidemiológica da tuberculose e co-infecção HIV/TB, em Ribeirão Preto-SP, de 1998-2006 / Epidemiological analysis of tuberculosis and HIV/TB Co-infection in Ribeirão Preto- SP, from 1998 to 2006.

Lucca, Maria Elvira Santos de 11 February 2008 (has links)
A pesquisa teve como objetivo analisar o Programa de Controle da Tuberculose (PCT) no município de Ribeirão Preto -São Paulo, no período de 1998 a 2006. Utilizou-se para este propósito indicadores epidemiológicos e de desempenho construídos a partir de dados das fichas de notificação de tuberculose (TB) armazenadas no sistema de informação o EPI-Tb, da Secretaria municipal de saúde deste município e os dados populacionais de estimativas do DATASUS, do período de estudo. Selecionaram-se para o estudo casos novos de TB notificados e residentes no município, por ano de diagnóstico, excluindo-se casos atendidos em outros municípios e presidiários. No período compreendido entre 1998 a 2006 foram notificados no EPI-Tb da SMS/Ribeirão Preto 1623 casos novos de tuberculose, sendo que houve queda no número absoluto de casos e no coeficiente de incidência de 47,8% (50,01- 26,08) dos casos no período ou 5,3% ao ano. O risco de ser um caso novo de TB foi 2,4 vezes maior para homens que para as mulheres. Apesar do número de casos notificados serem maiores na faixa etária de 15 a 49 anos, o risco de adoecer por TB foi maior na faixa etária acima de 50 anos, a partir de 2001. O percentual de co-infecção HIV/TB ficou em 27,1% (prevalência mínima), mas a prevalência máxima foi de 32,7%. A forma clínica mais freqüente para os casos novos foi a pulmonar com 85%, enquanto para os casos co-infectados esta forma esteve presente em 58,3% deles e a extra pulmonar em 27,8%. O local de descoberta dos casos de TB foi 51% em ambulatórios (públicos e privados), 39% em hospitais (universitários, público e privados) e 10% outras formas. Uma das fragilidades observadas foi a baixa detecção de casos de TB no município que nos últimos anos ficou próxima de 45% e que as unidades básicas de saúde e PCTs realizam apenas um quinto das baciloscopias de escarro para diagnóstico que deveriam realizar (segundo estimativas do MS). No entanto uma das fortalezas foi a implantação do tratamento supervisionado no município, que iniciou efetivamente em 1998, e foi aumentando gradativamente, chegando em 2006 a supervisionar 76% dos casos. Houve melhora nas taxas de cura, ficando próximo à 72% e 50,5%, para os casos novos sem co-infecção e com co-infecção HIV/TB, respectivamente. A taxa de mortalidade por TB no município apresentou ligeira tendência de queda no período. Apesar da baixa letalidade no período, 50,8% dos óbitos por TB só foram diagnosticados e notificados após o óbito; indicando dificuldade de acesso ao diagnóstico e tratamento da TB nestes casos. Conclui-se que para melhorar a detecção de casos de TB no município serão necessárias mudanças na forma de acolher os indivíduos suspeitos de TB na atenção básica de saúde, facilitando seu acesso a essas unidades, além de investigar mais sintomáticos respiratórios na comunidade. Algumas ações de controle da doença poderiam ser descentralizas, como o tratamento supervisionado e controle de comunicantes. Para os pacientes co-infectados HIV/TB apenas o tratamento supervisionado não está sendo suficiente para alcançarem sucesso no tratamento. / The objective of the present investigation was to analyze the Program of Tuberculosis Control (PTC) in the municipality of Ribeirão Preto- São Paulo, during the period from 1998 to 2006. Epidemiological and performance indicators were used for this purpose, constructed from data of the charts of tuberculosis (TB) notification stored in the information system of EPI-Tb, of the municipal health Secretariat of this municipality and from estimate population data of DATASUS regarding the study period. New TB cases notified regarding patients residing in the municipality were selected according to year of diagnosis, with cases attended in other municipalities and prisoners being excluded. A total of 1623 new cases of TB were notified to EPI-Tb of the SMS/Ribeirão Preto during the period from 1998 to 2006, with a fall in the absolute number of cases and a 47.8% (50,01-26,08) reduction of the coefficient of incidence being observed during this period, corresponding to 5.3% per year. The risk of being a new TB case was 2.4 times higher for men than for women. Although the number of notified cases was higher for the 15 to 49 year age range, starting in 2001 the risk of becoming ill with TB was higher in the age range above 50 years. The percentage of HIV/TB co-infection was 27.1% (minimum prevalence), but the maximum prevalence was 32,7%. The most frequent clinical form for the new cases was the pulmonary one (85%), while this form was present in 58.3% of co-infected cases and the extrapulmonary form in 27.8%. The site of detection of TB cases was public and private outpatient clinics in 51% of cases, university, public and private hospitals in 38%, and other sites in 10%. One of the fragilities observed was the low detection of TB cases in the municipality, which remained close to 45% over the last few years and the fact that the basic health units and PTCs perform only one fifth of the sputum bacilloscopies they should perform for diagnosis (according to Health Ministry estimates). However, one of the strong points was the implantation of supervised treatment in the municipality, which was effectively started in 1998 and increased gradually, with 76% of cases being supervised in 2006. There was an improvement in cure rates, that reached 72% and 50.5% for non-co-infected new cases and HIV/TB co-infected cases, respectively. The TB mortality rate in the municipality showed a slight tendency to a fall during the period. Despite the low lethality observed, 50.8% of the TB deaths were only diagnosed and notified after death, indicating a difficulty in access to diagnosis and treatment of TB in these cases. We conclude that, in order to improve the detection of TB cases in the municipality, changes are needed in the reception of individuals suspected to have TB at basic health units, facilitating their access to these units, in addition to the investigation of more persons with respiratory symptoms in the community. Some actions for the control of the disease such as supervised treatment and the control of communicants could be decentralized. Supervised treatment alone is not sufficient for HIV/TB-co-infected patients to achieve successful treatment.
510

Avaliação da resposta fotodinâmica em células de melanoma murino utilizando Photodithazine / Evaluation of photodynamic therapy response in murine melanoma cells using Photodithazine

Ono, Bruno Andrade 24 February 2016 (has links)
A terapia fotodinâmica é uma técnica que vem sendo aprimorada para o tratamento de cânceres e infecções e seu efeito terapêutico consiste na geração de espécies reativas de oxigênio que causam danos irreversíveis às células, levando-as a morte. Ela é considerada menos invasiva que outros tratamentos, podendo ser repetida diversas vezes e utilizada em conjunto com outros tratamentos sem o comprometimento do paciente. Um dos focos da terapia fotodinâmica é o tratamento de cânceres de pele melanoma devido a localização superficial das lesões e a elevada taxa de letalidade que a doença ocasiona, esta alta taxa esta relacionada a formação de tumores secundários em outras regiões do corpo que dificulta a cura. Neste trabalho buscou-se entender a interação do fotossensibilizador de segunda geração, Photodithazine, com as células de melanoma murino de linhagem B16F10. Foram analisadas a captação celular e a co-localização intracelular deste fotossensibilizador através da marcação de componentes celulares em microscopia confocal. Ensaios de viabilidade celular foram realizados para obtenção das concentrações menos citotóxicas sem e com luz, utilizando o teste de MTT. Foi realizada a caracterização do tempo de vida médio fluorescência do fotossensibilzador durante a terapia fotodinâmica em microscópio FLIM (fluorescence lifetime imaging microscopy). Os resultados indicaram que um maior tempo de incubação no escuro causa maior citotoxicidade para as concentrações acima de 0,1 mg/mL de Photodithazine. Os ensaios de terapia fotodinâmica apresentaram redução de mais de 90% de viabilidade celular para baixas concentrações de Photodithazine®, utilizando fluências acima de 2J/cm2. O tempo de vida médio de fluorescência do Photodithazine livre em solução apresentou tempo de 3,75 ns e quando ligado às células de 4,63 ns, durante a terapia fotodinâmica o tempo de vida médio de fluorescência apresentou alteração de aproximadamente 0,2 ns. Através do cálculo de coeficientes de correlação, foi observado a alta co-localização em mitocôndrias. / Photodynamic therapy is a technique manly applied in the treatment of cancers and infections. The principal compound of this therapy is the reactive oxygen species generated that react and damage various cellular components, causing cell death. Photodynamic therapy is considered minimally invasive and can be repeated several times without compromising the patient. One of the main focuses of photodynamic therapy is threatment of melanoma skin cancer due to it is superficial location of the lesions and also because the disease has a high rate of mortality, caused by the formation of secondary tumors elsewhere in the body that makes it difficult to cure. In this study, murine melanoma cells were studied in monolayer model using Photodithazine, a photosensitizer of second generation. Cellular uptake and intracellular co-localization of the photosensitizer was observed by labeling cellular components that were analyzed by confocal microscopy. Cell viability assays were performed to obtain the cytotoxic concentrations in the dark, using the MTT test. Using the less cytotoxic concentrations, photodynamic therapy trials was performed to obtain the cytotoxic fluences. Finally, the average lifetime fluorescence of photosensitizer was measured to characterize the photodynamic therapy in FLIM (fluorescence lifetime imaging microscopy). The results indicated that longer dark incubation cause greater cytotoxicity at the concentrations above 0.1 mg/mL of Photodithazine. Thereby the results of photodynamic therapy experiments observed the decreasing from over 90% cell viability at low concentrations of Photodithazine using fluences above 2 J/cm2. The average fluorescence lifetime of the free Photodithazine solution was 3.75 ns and cell-bound 4.63 ns, during the photodynamic therapy the average lifetime fluorescence changed approximately 0.2 ns. By calculating correlation coefficients, the high colocalization was observed in mitochondria.

Page generated in 0.0735 seconds