1,811 research outputs found
Perspectives of stem cell therapy in type 2 diabetes mellitus
A patogĂȘnese do diabetes mellitus tipo 2 (DM2) estĂĄ associada, basicamente, a dois mecanismos, resistĂȘncia Ă ação da insulina e disfunção secretĂłria das cĂ©lulas pancreĂĄticas. Atualmente, hĂĄ evidĂȘncias experimentais, clĂnicas e epidemiolĂłgicas, da participação do sistema imune e de mediadores inflamatĂłrios nesses mecanismos patogĂȘnicos. O interesse pelo tratamento regenerativo e pela utilização da terapia celular para o tratamento do DM2 deriva da importĂąncia da preservação da integridade funcional e quantitativa das cĂ©lulas β pancreĂĄticas. A utilização de cĂ©lulas-tronco para obtenção de controle glicĂȘmico em modelos experimentais de DM2 tem sido descrita jĂĄ hĂĄ alguns anos. Entretanto, em humanos, hĂĄ poucos estudos publicados nesse sentido. Embora haja vĂĄrias dificuldades a serem transpostas atĂ© que a terapia regenerativa do pĂąncreas para tratamento do DM2 seja uma opção viĂĄvel, ela poderĂĄ vir a ser, no futuro, uma ferramenta importante para o controle metabĂłlico da doença e redução de suas complicaçÔes crĂŽnicas.Type 2 diabetes mellitus (DM2) is associated with insulin resistance and secretory dysfunction of the -cells. There is now experimental, epidemiological and clinical evidence suggesting that the immune system and inflammatory mediators are involved in the pathogenesis of DM2. The interest in regenerative therapeutics and cellular therapy for DM2 is motivated by the importance of preserving -cell mass and function. Cellular therapy with stem cells for glycemic control has been tested in experimental models for some years however, there are only a few published studies using this approach in humans. Although there are many obstacles to overcome before regenerative therapy becomes a real option to treat DM2, it may be an important strategy to attain metabolic control and prevent chronic complications in the future
Linguagem/discurso como outra dimensĂŁo da perspectiva ctsa no ensino das ciĂȘncias/geociĂȘncias : ensaiando algumas relaçÔes possĂveis
A dimensĂŁo da linguagem/discurso faz parte de estudos sobre ciĂȘncia que relacionam ciĂȘncia, tecnologia e sociedade, apontando para a necessidade da consideração tanto da materialidade da linguagem (sistemas significantes) quanto da sua relação com o contexto histĂłrico-social de sua produção e com as relaçÔes entre os sujeitos. Esboçamos uma possĂvel base teĂłrico-metodolĂłgica para a construção de abordagens CTSA-discursivas, analisando a concepção de linguagem presente nesses estudos. Apresentamos trĂȘs casos em que se aplicam elementos dessa base teĂłrica envolvendo a anĂĄlise de textos (escritos e audiovisuais) da mĂdia jornalĂstica e de uma atividade em sala de aula envolvendo a linguagem cartogrĂĄfica. Apontamos a construção discursiva dos sujeitos/atores, a nĂŁo-neutralidade das produçÔes textuais e o deslocamento para a noção de textualização
Two methods of obtaining sol gel Nb2O5 thin films for electrochromic devices
Nb2O5 coatings prepared by the sol-gel route using the dip coating technique with sols prepared from alkoxide or chloroalkoxide (two different methods: sonocatalytic and conventional) precursors are a promising alternative for WO3 electrochromic coatings. The crystalline films (TT phase) sintered at 560 and 600 degrees C are transparent and present a deep blue colour under Li+ ion insertion. Electrochemical stability is excellent as these systems are fully reversible and stable and no change in colour, amount of charge exchanged and corrosion effect could be observed after 2000 voltammetry cycles between 2 and - 1.8 V versus Ag. The electrochemical and optical properties of these coatings have been determined as a function of sintering temperature. The superficial structure was visualized by atomic force microscopy (AFM) and scanning electron microscopy (SEM) and the Li+ diffusion coefficient was determined for both kinds of coatings
Density perturbations in Kaluza--Klein theories during a de Sitter phase
In the context of Kaluza-Klein theories, we consider a model in which the
universe is filled with a perfect fluid described by a barotropic equation of
state. An analysis of density perturbations employing the synchronous gauge
shows that there are cases where these perturbations have an exponential growth
during a de Sitter phase evolution in the external space.Comment: LaTex file, 10 pages. To be published in Classical and Quantum
Gravit
PolĂtica econĂŽmica e credibilidade: evidĂȘncias empĂricas e tĂ©cnicas economĂ©tricas [Economic policy and credibility: empirical evidence and econometric techniques]
This article presents a review of empirical literature regarding the credibility of economic policy, dedicating special attention to the econometric techniques used. The literature researched is comprised of two groups based on the type of econometric technique employed. However, within the main groups, reference is made to the four ways of conducting monetary policy currently being used in the world today: monetary aggregate targets, exchange rate peg, inflation targets, and preventive monetary policy with no explicit nominal peg. This text also refers to underlying theoretical models, when applicable. Brazilian empirical literature on this subject is reviewed in its own separate section.credibility, monetary policy, econometric models
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