998 resultados para dispositivos de liberación controlada de fármacos
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A análise termográfica é uma tecnologia proveniente da engenharia e utilizada na Segunda Guerra Mundial para detecção de forças armadas inimigas. Foi aplicada inicialmente na medicina para avaliação de articulações com artrites e hoje apresenta importante função no diagnóstico de câncer de mama em mulheres. Na medicina veterinária, há mais de trinta anos é técnica de diagnóstico auxiliar na clínica de equinos, para avaliação de processos inflamatórios tais como tendinites, desmites, artrites, miosites ou ainda no diagnóstico de fraturas, lesões na coluna ou em nervos periféricos. Por ser uma técnica com alta sensibilidade, exige que seu operador tenha treinamento e doutrinamento, não só para a execução dos exames, mas também para a análise de seus resultados. Diante disso, muitos pesquisadores afirmaram que os exames termográficos de aplicabilidade científica deveriam ser realizados em local com temperatura controlada, em torno de 23oC. Ao se trabalhar com equinos, torna-se difícil encontrar ambientes amplos o suficiente e com controle de temperatura para que os exames sejam feitos, o que praticamente inviabilizaria o uso da termografia na pesquisa com cavalos. Assim, este trabalho propôs um método de padronização das temperaturas que permite realizar termografias de extremidades de membros em ambientes variando entre 18 e 35oC. O método proposto, nomeado como PadTemp, foi validado em cavalos saudáveis e aplicado em experimentos de verificação de eficácia de fármacos e de acompanhamento de cirurgias ortopédicas.
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The traditional model of teaching little is modernized in recent decades. When in contact with this system, it is normal that the new-generation students feel unmo tivated in carrying out the proposed activities in the classroom. Considers Prensky (2001) these students, called Digital Natives, born with a modern way of thinking and learn and feel encouraged and motivated with activities that invite to interact. For this reason, it has been proposed the development of an object of learning in the form of application for Android tablets, exploring the internal sensors available in them, with the purpose of offering an interactive activity to students on the physical concepts involved in the process of photosynthesis in plants. For the construction, informational texts written in didactic language and easy to understand, illustrative images and animations were employed. In addition, we used the light sensor in the interactive activity on the process of photosynthesis so that the student could observe and understand how the environment is able to interfere with this process
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O desenvolvimento de sistemas de liberação de fármacos tem sido muito utilizado com o intuito de melhorar as propriedades biofarmacêuticas de fármacos. Sistemas de liberação controlada oferecem inúmeras vantagens quando comparados aos sistemas convencionais, o que os tornam candidatos promissores para a melhora da terapia de diversas doenças. Para o desenvolvimento destes sistemas, várias estratégias utilizam polímeros para modificar as propriedades farmacotécnicas das substâncias e partículas, com o objetivo de melhorar o direcionamento dos fármacos, bem como sua ação e toxicidade. Dentre estes polímeros, os mais utilizados são os polissacarídeos, por serem amplamente disponíveis e de baixo custo. São encontrados na natureza, em fontes diversas, como plantas, algas, microorganismos e animais. O dextrano, um polímero produzido por microorganismos, bem como seus derivados, têm recebido bastante atenção devido às suas características, como baixa toxicidade e alta degradabilidade enzimática, as quais o torna viável para o carreamento de fármacos. Com o dextrano é possível preparar sistemas de liberação controlada, uma vez que é possível se obter hidrogéis a partir dele, sem a utilização de reticulantes químicos. Hidrogéis são redes poliméricas tridimensionais hidrofílicas, que absorvem grande quantidade de água ou fluido biológico sem se dispersarem, o que denota a capacidade de intumescimento. Em sistemas de liberação baseados em hidrogéis, o perfil de intumescimento é uma característica de grande importância, pois pode modificar a propriedade de transporte do fármaco. Neste contexto, o presente trabalho tem o objetivo de avaliar a possibilidade da produção de hidrogéis de dextrano de diferentes pesos moleculares, para modular a liberação do fármaco praziquantel, utilizado no tratamento da esquistossomose... (Resumo completo, clicar acesso eletrônico abaixo)
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O processo de envelhecimento origina uma série de alterações na pele, dentre elas as o estresse oxidativo e as discromias. O ácido kójico tem a capacidade de atuar no tratamento do envelhecimento cutâneo em virtude de sua atividade ferro-quelante e de promover a despigmentação da pele devido inibir a tirosinase, impedindo a formação da melanina. Sistemas de liberação controlada de substâncias ativas, como os sistemas líquido-cristalinos, tem a propriedade de modular a permeação cutânea de fármacos, além de melhorar a sua ação. O presente trabalho tem como objetivo desenvolver e caracterizar um sistema líquido cristalino constituído por água e isonomanoato de cetoestearila (óleo), e estabilizado com o tensoativo álcool cetílico etoxilado e propoxilado contendo ácido kójico, avaliando sua permeação cutânea in vitro. A partir da construção de um diagrama de fases, foram selecionadas três formulações caracterizadas microscopicamente como CLs de fase hexagonal, denominada de A (35% O, 50 % T e 15% A), B (30% O, 50 % T e 20% A) e C (20% O, 50% T e 30% A), para prosseguir com o estudo, que consistiu na incorporação do ácido kójico na concentração de 2% e a realização dos ensaios de textura, bioadesão, reologia e de permeação e retenção cutânea in vitro. O ensaio de textura demonstrou que a formulação B com valores intermediários de água e fase oleosa apresentou valores intermediários de dureza, compressibilidade e adesividade, ideais para aplicação tópica. O ensaio de bioadesão mostrou que com o acréscimo de água na fórmula a força bioadesiva aumentou, o que pode melhorar a fixação do produto na pele do usuário. O ensaio reológico evidenciou que há aumento da viscosidade com acréscimo de água na formulação e que os sistemas analisados tratavam-se de fluidos pseudoplásticos com tixotropia tempo dependente... (Resumo completo, clicar acesso eletrônico abaixo)
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The materials designed to be used in electroluminescent (EL) devices construction are studied and improved since 1936. Great interests in the development of this kind of devices are mainly due to its low power consumption, flexibility, low cost and easy processing. One class of ELs devices with these characteristics are produced by employing a organic-polymeric/inorganic composite from a conductive polymer blend and an inorganic electroluminescent material (Zn2SiO4:Mn) dispersed in the polymeric matrix. This kind of device operates in d.c. or a.c. potentials, with EL of hundreds candela in the green region of the visible spectrum. However, few studies on the light emission were performed for these devices. In order to characterize devices made from composites, in this work is proposed a method of characterizing the electroluminescence associated with the impedance spectroscopy technique. To implement the technique of impedance spectroscopy was employ an experimental setup consisting of a source of a.c. voltage, an oscilloscope, and a reference resistor. Associated with this system, was use a photo diode and an analog electrometer to characterize the emitted light signal from the sample. The system was implemented allows characterization by impedance spectroscopy in the frequency range from 0.2 Hz up to 2 MHz and voltage amplitudes of 5 mV up to 20 kV. This system permits, at the same time, measurement of the RMS value of the luminance for devices in frequency range from 20 Hz up to 2 MHz. To test the system efficiency, an EL device was characterized showing analogous results to those reported in literature. By doing this, was demonstrated the efficiency of the system for electroluminescence characterization associated with the electrical characterization by impedance spectroscopy, for devices
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The project is a platform for education that provides a way where teachers can create and share educational content for their classes, and students can download that content to refer to it at any time. The solution is based on two Windows Phone 7 Apps: Kookaburra Teachers, where teachers can add content to their classes, and Kookaburra Students, where students can download and view the content of classroom. To realize the communication between these two applications, we use a Windows Azure server, that server is also responsible for processing some conversions, enabling real-time translation. In addition to storing all the content that is generated during the lessons
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In this work, it is presented a novel method for calculating some intrinsic parameters such as capture mean time, thermic emission mean time, capture probability and noise gain on quantum well infrared photodetectors. Such devices are built by depositing layers of semiconductors of different energy gap, forming quantum wells. The present method uses rate equations to describe the occupation of discrete states of the quantum wells, that together with noise gain equations given in literature, are solved self consistently. The input data of the method is experimental measurement of dark current (current measured with no relevant incident photon) versus applied bias. In order to validate this approach, the values obtained were compared with results from literature
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Recently, research on energy harvesting has increased substantially. Many researchers have concentrated their efforts to find the best configuration for these systems and to optimize their output power. In the process of energy harvesting, the electric energy is obtained by converting mechanics energy created by an environment vibration source by a transducer, for example, a thin piezoceramic film. That vibration source is, for example, a beam suffering some mechanic force able to generate a vibration in it, an oscillating beam is the best properly used example. Different mechanisms of electromechanical coupling have been developed to harvesting devices, and a particular interest has been given to the use of models that transform the mechanical vibration into electrical current using a piezoelectric element. In this paper we propose a model to energy harvesting from vibrations, from an oscillating beam, including non-linearities in the piezoelectric coupling and a non-ideal excitation in the material. From this model, it was developed a system to obtain some results about the harvested power by the material. It was demonstrated that the power captured was influenced by the effect of the nonlinearities of the piezoelectric coupling, modifying the system dynamic behavior
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Aspects are discussed on the chirality of drugs and their action in the human body, the benefits of using a drug in enantiomerically pure form and why, even today, despite the risks, many drugs are marketed as racemic mixture. Among the methods of separation there is the High Performance Liquid Chromatography (HPLC) which can be given in different ways using chiral additives in the mobile phase as in the system of ligand exchange in the ion pair system and the system of cavity or inclusion. Note also the wide variety of chiral stationary phases available in the market that allow high specificity using them according to the need and purpose of the method. The review of the topic is extremely important since it is a matter of public interest world that brings into play issues and financial policies
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Technology always advances and thus the device miniaturization and improved performance, besides multifunctionality, they become extremely necessary. A wave of research on the area tends to grow in number and importance in today's market, it is necessary to search for new materials, new applicability of the existing ones and new processes for increasingly cheaper costs. Dielectric materials are considered a key element in this sector being the main electrical properties its high dielectric constant and low dielectric loss. The Polymeric Precursor Method appears as a good alternative because is a low cost, simple process with controlled stoichiometry. In this method, two steps were performed. In a first step, the precursor solution was decomposed into powders and in a second step the precursor solution was converted in thin films. In this work, was used the polymeric precursor methods to get thin films where they were heat treated and characterized by XRD, SEM and AFM. We have obtained Bi3NbO7 thin films with good homogeneity and uniform distribution of grains were noted. We observed that the best condition to obtain the tetragonal phase is annealing the film at high temperatures for a longer soaking time and with excess of bismuth. Several oxides electrodes were evaluated aiming to obtain textured dielectric thin films
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This paper describes the main steps in the study of Senna spectabilis, as part of our bioprospection studies, with the isolation of spectaline, cassine and other piperidine alkaloids, as well as the preparation of semi-synthetic analogues, and the studies of their pharmacological and toxicological properties, which led to the establishment of two candidate drugs for the treatment of Alzheimer disease.