Efeitos fotocrômico e termocrômico em ormosils dopados com azobenzenos

The sol-gel process and the wide variety of alkoxides commercially available have facilitated the processing of various Organic-Inorganic Hybrid Materials. In general, the hybrids are excellents matrix to incorporate organic or inorganic dopants that presents photochromic, thermochromic, and halochromic effects and in some cases photorefractive effects. The GPTS-TEOS hybrid matrix when deposited in the form of film is very resistant, adherent, has excellent transparency in visible region and allows to be doped with various azo-dye and metal salts of unusual oxidation states. One of the main characteristics of the azo-dyes when immersed in some hybrid matrix , is the capacity to isomerizes through group Azo (-N = N-) would can be commutated between the Cis (Z) and Trans (E) configurations by means of light or heat. Our goal was through the sol-gel process to prepare hybrid films of GPTS-TEOS doped with azo-dyes Methyl Red and Disperse Red 1, and characterize them optically. The characterizations are performed using techniques of UV / Vis spectroscopy, to identify changes in the absorption band of azo-dyes in the presence of optical pumping, (photochromic effects), in function of temperature (thermochromic effect). These properties are of wide scientific and technological interest because they will contribute to the confection Smart Windows (windows sensible to light), temperature sensors monitored optically and also in the recording of amplitude and phase diffraction gratings

Efeito da amostragem de informação visual no comportamento locomotor adaptativo de pacientes com doença de Parkinson idiopática

Pouco se sabe a respeito da marcha de pacientes com doença de Parkinson (DP) em ambientes irregulares. Mais especificamente, não foram encontrados estudos que manipularam a informação visual na tarefa de ultrapassar obstáculo. Assim, o objetivo deste estudo foi analisar o papel da visão no comportamento locomotor durante a ultrapassagem de obstáculos de diferentes alturas em indivíduos com DP idiopática, manipulando experimentalmente a disponibilidade das informações visuais. Participaram 14 idosos com DP, classificados entre os estágios 1 e 2,5 da escala de Hoehn & Yahr. Os participantes foram convidados a percorrer andando uma passarela de 8 metros, em condições sem obstáculo (SO) e com obstáculo baixo (OB) ou alto (OA). As tentativas foram apresentadas combinando condições de obstáculo (SO, OB e OA) e de visão (IVD e IVE), em 3 tentativas por condição, totalizando 18 tentativas; realizadas em 2 blocos. A manipulação de informação visual foi realizada através do uso de óculos de lentes de cristal líquido e a análise cinemática foi realizada tridimensionalmente. As variáveis dependentes selecionadas incluíram os parâmetros espaciais e temporais das fases de aproximação e ultrapassagem do obstáculo. Para o tratamento dos dados, foram empregadas duas MANOVAs. Os resultados revelaram que tanto a manipulação visual como a manipulação do terreno influenciaram no comportamento locomotor dos pacientes. Na fase de aproximação, a presença do obstáculo provocou modificações nos parâmetros locomotores, refletindo em menores valores médios de comprimento e velocidade da passada nas condições OB e OA do que na condição SO. Em relação à informação visual nesta mesma fase, a anulação do fluxo óptico provocou diminuição do comprimento e da velocidade da passada, da cadência e da porcentagem da fase de suporte simples e aumento da duração... (Resumo completo, clicar acesso eletrônico abaixo)

Análise fractal de fraturas em regime linear elástico: modo I de carregamento

For the development of this graduate work of fractal fracture behavior, it is necessary to establish references for fractal analysis on fracture surfaces, evaluating, from tests of fracture tenacity on modes I, II and combined I / II, the behavior of fractures in fragile materials, on linear elastic regime. Fractures in the linear elastic regime are described by your fractal behavior by several researchers, especially Mecholsky JJ. The motivation of that present proposal stems from work done by the group and accepted for publication in the journal Materials Science and Engineering A (Horovistiz et al, 2010), where the model of Mecholsky could not be proven for fractures into grooved specimens for tests of diametric compression of titania on mode I. The general objective of this proposal is to quantify the distinguish surface regions formed by different mechanisms of fracture propagation in linear elastic regime in polymeric specimens (phenolic resin), relating tenacity, thickness of the specimens and fractal dimension. The analyzed fractures were obtained from SCB tests in mode I loading, and the acquisition of images taken using an optical reflection microscope and the surface topographies obtained by the extension focus method of reconstruction, calculating the values of fractal dimension with the use of maps of elevations. The fractal dimension was classified as monofractal dimension (Df), when the fracture is described by a single value, or texture size (Dt), which is a macroscopic analysis of the fracture, combined with the structural dimension (Ds), which is a microscopic analysis. The results showed that there is no clear relationship between tenacity, thickness and fractal values for the material investigated. On the other hand it is clear that the fractal values change with the evolution of cracks during the fracture process ... (Complete abstract click electronic access below)

Efeitos da ação central do peróxido de hidrogênio na ingestão de água, na excreção renal de água e eletrólitos e na expressão de Fos induzidos pela estimulação colinérgica da área sptal medial

A área septal medial (ASM), situada no prosencéfalo, está envolvida na regulação cardiovascular e no controle do balanço hidroeletrolítico. Esta área é rica em receptores colinérgicos e a ativação dos mesmos induz ingestão de água, natriurese e antidiurese. A ASM também envia projeções aos núcleos paraventricular (NPV) supra-óptico (NSO), os quais contêm os neurônios que secretam vasopressina e ocitocina. Existem evidências experimentais demonstrando que as espécies reativas de oxigênio podem participar do controle de respostas fisiológicas. Resultados recentes de nosso laboratório demonstraram que uma espécie reativa de oxigênio, o peróxido de hidrogênio (H2O2), injetado no ventrículo lateral (VL) reduz a ingestão de água e a resposta pressora induzida por ANG II e carbacol (agonista colinérgico) também injetados no VL. Por isso, o presente estudo teve como objetivo estudar os efeitos da injeção de H2O2 na ASM sobre a ingestão de água, sobre a excreção renal de água e eletrólitos e sobre a expressão da proteína c-Fos no NSO produzidos pela injeção de carbacol também na ASM. Para realizar este trabalho, foram utilizados ratos com cânulas de aço inoxidável implantadas na ASM. A ingestão de água e a excreção renal de água e eletrólitos foram estudadas em ratos que receberam injeções de H2O2 (5 mol/0,5 μl) ou PBS (veículo, 0,5 l) na ASM e, após um minuto, injeção de carbacol (4 nmol/0,5 l) ou salina (NaCl 0,15 M / 0,5 l) também na ASM. A ingestão de água induzida pelo carbacol, através da estimulação colinérgica, foi menor nos ratos que receberam a injeção prévia de peróxido de hidrogênio (8 ± 2,0 ml / 1 h, p<0,05) comparado àqueles que receberam veículo, também na ASM (16,6 ± 1,9 ml / 1 h, p<0,05). Além disso, houve diferença significativa na ingestão de água dos ratos + salina, grupo controle... (Resumo completo, clicar acesso eletrônico abaixo)

Processamento do compósito de fibra de capim-sapê / epóxi e avaliação da resistência à flexão “t” de Student

In recent years a great worldwide interest has arisen for the development of new technologies that enable the use of products with less environmental impact. The replacement of synthetic fiber plants is a possibility very important because this fiber is renewable, biodegradable and few cost and cause less environmental impact. Given the above, this work proposes to develop polymeric composites of epoxy resin and study the behavior of these materials. Both, the epoxy resin used as matrix in the manufacture of sapegrass fiber composite, as tree composites formed by: epoxy/unidirectional sapegrass long fiber, 75% epoxy/25% short fiber, by volume, and 80% epoxy/20% short fiber, by volume, were characterized by bending, and the composites produced with short fibers random were inspected by Optical Microscopy and Acoustics Inspection (C-Scan). For the analysis of the sapegrass fiber morphology, composites 75% epoxy/25% short fiber (sheet chopped) and 80% epoxy/20% short fiber images were obtained by optical microscope and the adhesion between polymer/fiber was visualized. As results, the flexural strength of composites epoxy/unidirectional long fibers, 75% epoxy/25% short fiber and 80% epoxy/20% short fiber were 70.36 MPa, 21.26 MPa, 25.07 MPa, respectively. Being that composite showed that the best results was made up of long fibers, because it had a value of higher flexural strength than other composites analyzed

Efeito do Estrôncio (Sr) no tratamento de modificação do eutético da liga Al-1%Si

This study aimed to analyze the cooling curves, micro and macrograph alloy Al-1 %Si without the addition of strontium modifier and with the addition of the same. One of the ways of improving mechanical properties of alloy Al -Si is through the modification process. For the experiments two billets of the alloy Al-1%Si cast iron mold in a billet with addition of 0.02% strontium by weight, and the other billet without the addition of modifier were fused. In the solidification process of billet temperature was monitored and recorded every second for later plotting in Origin 8 program and analyzes the cooling curves obtained. The billets were cut and passed by grinding and polishing to perform the macrograph and micrographs. The results concerning the macrograph indicated that billet without the addition of Strontium particle size obtained was more refined than the billet where the strontium modifier was added. Regarding the micrograph, photos stemmed from the optical microscope didn´t show the expected modification effect by the addition of Strontium. This suggests that the low amount of silicon (1 %) present in the alloy used in this study interfered in the change process, because according to the literature review, Strontium 0.022 % by weight is sufficient to fully modify an alloy with 7% Silicon. The results from the cooling curve showed that both the eutectic temperature and the solidification time remained unchanged with the addition of strontium

Histologia comparada de brânquias, fígado e sangue em peixes da espécie Prochilodus lineatus, expostos a águas contaminadas

Os estudos hematológicos das diferentes espécies de peixes são de interesse ecológico e fisiológico, auxiliando na compreensão da relação entre as características sanguíneas, a filogenia, a atividade física, o hábitat e a adaptabilidade dos peixes ao ambiente. No experimento realizado foram testados os efeitos de águas contaminadas em parâmetros hematológicos de peixes da espécie Prochilodus lineatus, em períodos de coleta de 7 e 20 dias, nos quais o sangue foi coletado com seringas heparinizadas, foram montadas lâminas de esfregaço , as quais foram coradas pelo corante de Leishman. Estas lâminas foram analisadas e fotografadas com o auxílio de um microscópio óptico Leica, no qual foram feitas contagens totais de células brancas e contagens diferenciais de trombócitos e leucócitos, para a análise estatística. O grupo exposto ao Lago Azul apresentou uma elevação no número de leucócitos e no total de células brancas, evidenciando que os contaminantes químicos do ambiente estavam atuando de forma semelhante a um antígeno no corpo do animal fazendo com que suas células de defesa se proliferassem. Quanto ao grupo exposto ao detergente, observou-se que após os vinte dias de experimento ocorreu uma diminuição no número de trombócitos. Tais resultados evidenciam que a variação no número de leucócitos apresentou-se como um indicador de poluição ambiental e que os detergentes biodegradáveis podem em certo tempo de exposição ocasionar um déficit em funções vitais de peixes como à coagulação e a prevenção contra infecções, eventos ligados diretamente com os trombócitos. A maioria dos vertebrados aquáticos possui brânquias, estruturas especializadas nas trocas gasosas e responsáveis por grande parte das trocas iônicas. Este órgão acaba por absorver grande parte das substâncias presentes na água, que ao caírem na...(Resumo completo, clicar acesso eletrônico abaixo)

Fractografia quantitativa e o conceito de tenacidade à fratura para a análise do efeitodo choque térmicos em TiO2

The present study evaluated the use of semicircular bending test (SCB) as an alternative to conventional bending test to examine the effect of thermal shock. Still, studies the behavior of fracture surfaces generated by monofractal behavior analysis, which allows us to evaluate the contributions of the microstructure and the mechanical context in forming reliefs during the crack propagation. The fractal analysis is made from elevation maps obtained by reconstruction method by extension of the focus stacks of digital images acquired in microscope. The specimens used were samples semicircular pressed TiO2 (rutile) with and without heat shock, prepared for testing mode I loading. Were also produced, specimens in the form of bars for Weibull statistical analysis. From the three-point bending test, we found the variation of fracture toughness between the samples after the heat shock and natural condition. The SCB test was feasible for the analysis of thermal shock resistance. The results showed that the value of the fracture toughness decreases as the heat shock treatment

Manifestações oculares na leishmaniose

The Canine Visceral Leishmaniasis is a chronic disease of endemic character, caused by Leishmania Chagasi in Americas. The inoculation of the promastigote form in the individual triggers a local and widespread immune reaction with formation of inflammatory infiltrates and deposition of immune complexes in tissues. Initial clinical symptoms of the disease are: weight reduction, hepatomegaly, splenomegaly and, according to the disease chronicity, signs such as alopecia, erythema, onychogryphosis, arthropathies, renal diseases, pyoderma, seborrheic dermatitis, muscle atrophy and Ocular diseases. Ocular diseases are often reported and are result of the direct parasitism or immune-mediated mechanisms caused by the disease. The Leishmania spp have greater affinity for the anterior segment, so that anterior uveitis is one of the most frequently diagnosed injuries. Blepharitis diffuse and Keratoconjunctivitis also appear as important ocular changes. In histological section, inflammatory infiltrates and macrophages with amastigote form are observed in all ocular tissues, with the exception of the retina and optical nerve. In the clinical analysis and disease diagnosis, should be considered the differential diagnosis, such as Ehrlichiosis and systemic hypertension, because these may cause some ocular manifestations similar to those observed in leishmaniasis

Estudo da variação do limite de resistência à tração ao longo da bobina de vergalhão de alumínio 1350 AA

Therebar of aluminum 1350 AA produced by CBA are used inthe manufacture of wires and cables for electric power transmission, which marketshows increasingly favorableto aluminum due to itslow densityand high electrical conductivity, but to ensure that this materialmeets all specifications of projectsfor electricity transmission, it must have homogeneity in the chemicaland mechanicalproperties.One of the points of improvement in the process of rod production isreducing the high variation of the limitof tensile strengthalong the coils, therefore, this work seeks a better understanding of the factors that significantly influence the mechanical properties of rebar, specifically assessing the influence oftemperatureat the output of the coils, which can cause a recovery effect on the material andif thereare relevantdifferences between the two modes of rebar production: auto and manual.Samples of six coils have been specifically produced forthis study, which weresubsequently subjected to different annealing temperatures for one hour and ten minutes, similar to what occurs in the output of the coil from the machine. The tensile tests showed that aluminum 1350 AA is significantly influenced by temperature, whose behavior was very similar to that presented in the literature. It was found that the phenomenon of recovery occurred more significantly at high temperatures. Through the optical electron microscope Zeiss, 18 surface maps were made with 100x magnification for each sample in different conditions and the images were analyzed using entropy and fractal dimension, aiming to relate the condition of surface hardening on mechanical property of the samples in that condition. The results showed that these methods can be applied, provided they do not have any kind of imperfection on the surface, once they can influence the results. The study concluded that a more efficient cooling is required in ... (Complete abstract click electronic access below)

Processo de esmerilhamento, polimento e caracterização de um Shear Plate

Shearplate is an optical glass plate having two flat surfaces and a small angle between them. The use of a high quality shear plate is essential to implement shear interferometric technique . The shear interferometry is a technique used to evaluate the light beam collimation. In order to guarantee the shearplate quality , the complete manufacturing process must be thoroughly monitored. In the manufacturing process, the first step consisted of the glass selection. The selected glass has been submitted to the process of cutting, gluing, chamfering, grinding and polishing. Each phase has been strictly monitored. The quality of the final result depends extremely on an appropriate starting condition, which arises from the grinding process, as the polishing process only recovers the brightness of the part, acting on a small scale on the wearing off of the part, as well as not changing the structured obtained in the grinding process. Respecting all stages of the manufacturing process, the quality of the part has evolved to a good result. The best result obtained showed PV distance of 162 nm, slightly less than λ / 4. This result is significant because the dimensions of the piece with respect to the dimensions of the polisher what interferes directly in the results. The closer are the dimensions of piece and the dimensions of the polisher, the greater the difficulty in controlling the propagation of errors

Expansão ex vivo de células uroteliais em scaffolds 3D

Malformations and possible damages to the urogenital system can be originated in the embryonic period. Moreover, fire guns, knives and accidents, where there is the disruption of the urethra, also cause these lesions. The objective was to analyze the contribution of tissue engineering in the construction of neo-urethra, developed by bioengineering. We performed an urothelial ex vivo expansion of cells in 3D scaffolds (platelet gel matrix and acellular porcine aorta) to assess the contribution of this technique in the construction of a neo-urethra. Mechanical dissociation was made of the inner wall of 10 North Folk rabbit’s bladder, weighing 2.5 to 3.0 kg. After dissociation the cell content was centrifuged and obtained a pellet of urothelial cells. The pellet was ressuspended in culture medium DMEM F12 and cells were maintained in culture for 15 days. Immunohistochemical analysis characterized the urothelial culture. The cells were then implanted in the scaffold - platelet gel. In a second experiment using aortic porcine acellular matrix were implanted urothelial cells alone and urothelial cells on platelet gel, on the inner wall of the scaffold - aorta, with space for setting bordered by a urethral probe. The complex probe - cells - aorta and probe - cells in platelet gel - aorta, were sealed with suture material and culture were maintained in a humidified 37ºC incubator with 5% CO2 in air for 12 days to subsequent histological analysis of urothelium cell adhesion to the scaffolds. By observation under an optical microscope, we could see the growth of cells in the scaffold platelet gel, from a monolayer in to a three-dimensional structure. In the acellular porcine aortic matrix containing the platelet gel, we could observe a few quantity of urothelial cells adhered. However with the acellular porcine aortic matrix in which was implanted only the urothelial cells, we have obtained adhesion to the wall

Estudo do comportamento térmico e reológico de amidos na conformação cerâmica de compostos multicamada com alumina, titanato de alumínio e dióxido de titânio

The project aims to develop ceramic compounds with gradients of the mechanical properties, using the molding technique with commercial starches. To understand the process of interaction between starch and ceramic powders, the proposed methodology involves viscometry tests (up to 200 °C). Viscometric assays were carried out with slurries of alumina, titania and aluminum titanate with potato starch, cassava and corn. The specimens were tested for dilatometry, thermomechanical, thermal shock, mechanical and characterization by SEM. The ceramic powders and starches were analyzed using the optical microscope to measure the size of these. It was made of th kinetics of starch gelatinization and titania with the cornstarch in theoptical microscope to observe how the grains of starch behaved in welling

Análise dosimétrica de aplicadores de Betaterapia

Betatherapy is a special medical technique using a radioactive source of strontium-90 for the treatment of superficial lesions, especially in dermatology and ophthalmology. Strontium-90 sources emit β radiation, which possesses high ionization power, but a very short distance propagation into matter. This work presents a method of dosimetric analysis of betatherapy using strontium- 90-based instrumentation, commonly used against superficial diseases, such as keloid and pterygium, aiming the description of the dosimetry analysis procedures, which can be easily implemented on tradiotherapy services that offers the betatherapy treatment. IBF-MEDIX radiographic films (conventional films) were exposed to betatherapy applicators during different time intervals according to the activity of the source, and afterwards the optical densities (O. D.) of the radiographic images were measured using an optical densitometer MACBETH. Therefore, the parameters used to make the dosimetric analysis in betatherapy were standardized, as the exposure time depended on the geometry and size of the source, providing an efficient and fast method of dosimetric analysis of the betatherapy equipment of the services, the majority of which do not have the scientific structure to perform this study

Aspectos gerais da Toxoplasmose

One tthird of the world population is infected with Toxoplasma gondii, in most cases, asymptomatic. There are records of infection in birds and mammals, including the dog. Systemic clinical signs of canine toxoplasmosis are variable, however, the animals may manifest ocular signs: anterior mononuclear uveitis, retinitis, choroiditis, extraocular myositis, scleritis and optic neuritis. This paper aims to demonstrate through bibliography revision some aspects of canine toxoplasmosis as clinical signs focusing on the ocular manifestations, potential zoonotic disease and the importance of public health