984 resultados para Proportional counters.


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The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatability, hystheresis and linearity. The test was accomplished in a bench, specially developed for this aim. As a result, were obtained three curves of opening percentage as function of flow rate, describing three opening and closing increments in two different work pressures. The servo-valve presented a good repeatability, reasonable hysteresis and a typically quadratic curve. This one maintained the low cost target. These results were very satisfied because the non-linearity and the hysteresis could be easily corrected by software.

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The aim of this study was to analyse seed dispersal and establishment of Solanum thomasiifolium in an area of nativo vegetation in Espirito Santo state on the southeastern Brazilian coast. Ten species of birds, the crab-eating fox (Cerdocyon thous), and one species of lizard (Tropidurus torquatus) fed on S. thomasiifolium fruits and dispersed viable seeds in their faeces. The proportional contribution of each of these groups to seed dispersal was 77% (birds), 19% (crab-eating fox) and 4% (lizards). Ants also contributed to seed dispersal. More seeds were deposited in vegetation islands than in the surrounding open areas. Germination rates of seeds collected directly from fruit (control), bird droppings, the faeces of crab-eating foxes and lizards were, respectively, 64, 64, 53, and 80 %. Differences among these rates were all significant, except between birds and control. Lizards were important as seed carriers between nearby islands and they expelled a higher proportion of viable seeds. Birds and the crab-eating foxes did not enhance seed germination, but promoted seed dispersal over a wider area. Plant architecture, fruit productivity, fruit characteristics and the diversity of frugivores are important for the success of S. thomasiifolium in habitat colonization.

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We analyzed the structure of the understory community in the Atlantic Forest sensu lato, for which phytosociological descriptions of the understory are lacking. We delineated 50 plots of 10 × 20 m each at four sites within an Araucaria forest (a subtype of Atlantic Forest), located in the municipalities of Bananal, Campos do Jordão, Itaberá and Barra do Chapéu, all of which are in the state of São Paulo, Brazil. To sample the resident species of the understory, we randomly selected five 1 × 1 m subplots within each plot, resulting in a total sampling area of 250 m² at each site. We identified differences among the locations, mostly due to proportional differences in growth forms, in terms of species richness and the importance values within the community. Factors potentially influencing the understory structure include macroclimatic and microclimatic conditions, as well as forest fragmentation, the abundance of deciduous trees in the canopy, the surrounding vegetation and geographic location.

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INTRODUCTION: Like in humans, lower amounts of glycogen are present in tissues of diabetic rats. However, training or drugs that lower glycemia can improve the metabolic control. Metformin increased glycogen while decreased glycemia in normal rats stressed by exercise. OBJECTIVE: In this work we investigated if regular exercise and metformin effects improve the metabolism of diabetic rats. METHODS: Alloxan diabetic Wistar rats treated with metformin (DTM) or not (DT) were trained. Training consisted of 20 sessions of 30 min, 5 days a week. Sedentary diabetic rats served as control (SD and SDM). Metformin (5.6 µg/g) was given in the drinking water. After 48 h resting, glucose (mg/dl) and insulin (ng/mL) was measured in plasma and glycogen (mg/100 mg of wet tissue) in liver, soleus and gastrocnemius. RESULTS: Glycemia decreased in DM group from 435±15 to 230±20, in DT group to 143±8.1 and in DTM group to 138±19 mg/dl. DM group had proportional increase in the hepatic glycogen from 1.69±0.22 to 3.53±0.24, and the training increased to 3.36 ± 0.16 mg/100 mg. Metformin induced the same proportional increase in the muscles (soleus from 0.21±0.008 to 0.42±0.03 and gastrocnemius from 0.33±0.02 to 0.46±0.03), while the training promoted increase on gastrocnemius to 0,53 ± 0,03, only. A high interaction was observed in liver (glycogen increased to 6.48±0.34). CONCLUSION: Very small oral doses of metformin and/or, partially restored glycemia in diabetic rats and decreased glycogen in tissues. Its association with an exercise program was beneficial, helping lower glycemia further and increase glycogen stores on liver of diabetic rats.

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Universidade Estadual de Campinas. Faculdade de Educação Física

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Universidade Estadual de Campinas . Faculdade de Educação Física

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This study evaluated the influence of a cola-type soft drink and a soy-based orange juice on the surface and subsurface erosion of primary enamel, as a function of the exposure time. Seventy-five primary incisors were divided for microhardness test (n=45) or scanning electron microscopy (SEM) analysis (n=30). The specimens were randomly assigned to 3 groups: 1 - artificial saliva (control); 2 - cola-type soft drink; and 3 - soy-based orange juice. Immersion cycles in the beverages were undertaken under agitation for 5 min, 3 times a day, during 60 days. Surface microhardness was measured at 7, 15, 30, 45 and 60 days. After 60 days, specimens were bisected and subsurface microhardness was measured at 30, 60, 90, 120, 150 and 200 µm from the surface exposed. Data were analyzed by ANOVA and Tukey’s test (a=0.05). Groups 2 and 3 presented similar decrease of surface microhardness. Regarding subsurface microhardness, group 2 presented the lowest values. SEM images revealed that after 60 days the surfaces clearly exhibited structural loss, unlike those immersed in artificial saliva. It may be concluded that erosion of the surfaces exposed to the cola-type soft drink was more accentuated and directly proportional to the exposure time.

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Os efeitos da concentração de ágar no crescimento de explantes e na formação de calos foram avaliados em culturas axênicas de gametófitos femininos de morfos de coloração verde e vermelha de Gracilaria domingensis (Kützing) Sonder ex Dickie. Culturas unialgáceas foram mantidas em água do mar esterilizada (30-32 ups) enriquecida com 25% da solução de von Stosch (VSES 25%), 22 ± 2 °C, fotoperíodo de 14 h, irradiância de 50-80 µmol de fótons m-2 s-1. Para a obtenção de explantes axênicos, segmentos apicais e intercalares dos dois morfos foram cultivados por 48 h em meio VSES 25% com adição de uma solução antibiótica e antifúngica, e submetidos a uma lavagem com uma solução de água do mar esterilizada com 0,5% de hipoclorito de sódio e 200 µL L-1 de detergente por 20 segundos. Para avaliar os efeitos da concentração de ágar, os segmentos axênicos foram inoculados em meio ASP 12-NTA com concentrações distintas de ágar que variaram de zero a 1%. A adição de ágar no meio inibiu o crescimento dos segmentos apicais de ambos os morfos, bem como o crescimento de segmentos intercalares do morfo verde. Observou-se uma tendência geral no crescimento dos explantes, onde a taxa de crescimento foi inversamente proporcional à concentração de ágar. A adição de ágar no meio induziu a formação de três tipos de calo, denominados conforme a região do explante onde se originaram: calo apical, calo basal e calo intermediário. As concentrações de 0,5% e 0,7% de ágar foram as concentrações ótimas para indução de calos basais e calos intermediários no morfo verde, respectivamente. A presença de ágar foi essencial para a formação de calos intermediários e apicais. Os resultados indicam que o ágar apresenta um papel na regulação dos processos morfogenéticos em morfos pigmentares de G. domingensis.

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The vials filled with Fricke solutions were doped with increasing concentrations of Photogem®, used in photodynamic therapy. These vials were then irradiated with low-energy X-rays with doses ranging from 5 to 20 Gy. The conventional Fricke solution was also irradiated with the same doses. The concentration of ferric ions for the Fricke and doped-Fricke irradiated solutions were measured in a spectrophotometer at 220 to 340 nm. The results showed that there was an enhancement in the response of the doped-Fricke solution, which was proportional to the concentration of the photosensitizer. The use of such procedure for studying the radiosensitizing property of photosensitizers based on the production of free radicals is also discussed.

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It has been demonstrated that there is an association between serum lipoproteins and survival rate in patients with ischemic cardiomyopathy, as well as in patients with non-ischemic causes of heart failure. We tested the hypothesis of an association between serum lipoprotein levels and prognosis in a cohort of outpatients with heart failure, including Chagas' heart disease. The lipid profile of 833 outpatients with heart failure in functional classes III and IV of the New York Heart Association, with a mean age of 46.9 ± 10.6 years, 655 (78.6%) men and 178 (21.4%) women, was studied from April 1991 to June 2003. The survival rate was estimated by the Kaplan-Meyer's method and the Cox proportional hazards models. Etiology of heart failure was ischemic cardiomyopathy in 171 (21%) patients, Chagas' heart disease in 144 (17%), hypertensive cardiomyopathy in 136 (16%), and other etiologies in 83 (10%). In 299 (36%) patients, heart failure was ascribed to idiopathic dilated cardiomyopathy. Variables significantly associated with mortality were age (hazard ratio, HR = 1.02; 95%CI = 1.01-1.03; P = 0.0074), male gender (HR = 1.77; 95%CI = 1.2-2.62; P = 0.004), idiopathic dilated cardiomyopathy (HR = 1.81; 95%CI = 1.16-2.82; P = 0.0085), serum triglycerides (HR = 0.97; 95%CI = 0.96-0.98; P < 0.0001), and HDL cholesterol (HR = 0.99; 95%CI = 0.99-1.0; P = 0.0280). Therefore, higher serum HDL cholesterol and higher serum triglycerides were associated with lower mortality in this cohort of outpatients with heart failure.

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Objetivou-se, neste trabalho, avaliar as alterações físico-químicas proporcionadas pelo tratamento de centros tendinosos diafragmáticos homólogos em solução alcalina seguida de liofilização, para implantação na fáscia interna do músculo reto do abdome de eqüinos. As amostras foram tratadas em períodos de 24, 48, 72, 120 e 144 horas, liofilizadas e analisadas quanto à homogeneidade, flexibilidade e resistência à sutura das amostras. Posteriormente foram caracterizadas por calorimetria exploratória diferencial e microscopia eletrônica de varredura. Para a implantação nos eqüinos, foram utilizadas amostras tratadas por 72 horas seguidas de liofilização, amostras conservadas em glicerina 98% e amostras apenas liofilizadas, que foram retiradas após uma, nove e 18 semanas para avaliar a existência de aderências. Verificou-se que a homogeneidade e a flexibilidade são diretamente proporcionais ao aumento do tempo de tratamento em solução alcalina, enquanto que a resistência é inversamente proporcional ao aumento de tempo, sendo o tratamento por 72 horas intermediário para estas características. A calorimetria exploratória diferencial mostrou que o tratamento não desnatura o colágeno presente nas amostras. Na microscopia eletrônica de varredura, observou-se que o aumento de tempo de tratamento proporciona expansão de zonas menos densas do material. Em relação à formação de aderências, as amostras apenas liofilizadas apresentaram grau máximo na formação da classificação proposta, seguida pelas amostras conservadas em glicerina 98% com grau médio e as amostras tratadas em solução alcalina e liofilizadas, que foram classificadas em grau mínimo. Concluiu-se que o tratamento por 72 horas seria mais apropriado para implantação e que a integração tissular com a parede abdominal foi melhor em relação às amostras apenas liofilizadas e às conservadas em glicerina.

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OBJECTIVE: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%). RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.

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OBJETIVO: Avaliar a adequação da ingestão de energia, macro e micronutrientes em adolescentes modelos de passarela. MÉTODOS: Estudo transversal de 33 adolescentes modelos e 33 não modelos, de 15 a 18 anos, pareadas por idade e índice de massa corpórea (IMC). A ingestão alimentar foi avaliada por meio de registro alimentar de três dias, sendo calculados os valores médios de energia, em kcal, os valores proporcionais dos macronutrientes em relação ao valor calórico total da dieta consumida, bem como os valores médios/medianos dos seguintes micronutrientes: cálcio, ferro, zinco, fósforo, magnésio, folato, vitamina D, vitamina C, vitamina A e vitamina E. RESULTADOS: Verificou-se que 24% das adolescentes do estudo apresentaram IMC abaixo dos valores mínimos para a idade. A média de ingestão de energia foi menor entre as modelos, em comparação às adolescentes não modelos (1.480,93±582,95 versus 1.973,00±557,63 kcal) (p<0,05). A ingestão de gorduras acima do recomendado foi semelhante entre os grupos - 30,3% das adolescentes modelos e 36,4% das adolescentes não modelos (p>0,05). O consumo inadequado de micronutrientes como o cálcio, ferro, zinco, magnésio, fósforo, vitaminas lipossolúveis, folato e ácido ascórbico ocorreu em ambos os grupos. CONCLUSÕES: A baixa ingestão energética (kcal) entre as modelos e a ingestão insuficiente de minerais e vitaminas alertam para que as agências de modelos comprometam-se com a saúde dessas adolescentes, garantindo um acompanhamento médico e nutricional.

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OBJETIVO: Analisar os fatores relacionados à determinação e às desigualdades no acesso e uso dos serviços de saúde por idosos. MÉTODOS: Estudo integrante do Projeto Saúde, Bem-estar e Envelhecimento (SABE), no qual foram entrevistados 2.143 indivíduos com 60 anos ou mais no município de São Paulo, SP, em 2000. A amostra foi obtida em dois estágios, utilizando-se setores censitários com reposição, probabilidade proporcional à população e complementação da amostra de pessoas de 75 anos. Foi mensurado o uso de serviços hospitalares e ambulatoriais nos quatro meses anteriores à entrevista, relacionando-os com fatores de capacidade, necessidade e predisposição (renda total, escolaridade, seguro saúde, morbidade referida, auto-percepção, sexo e idade). O método estatístico utilizado foi regressão logística multivariada. RESULTADOS: Dos entrevistados, 4,7% referiram ter utilizado a internação hospitalar e 64,4% o atendimento ambulatorial. Dos atendimentos ambulatoriais em serviço público, 24,7% ocorreram em hospital e 24,1% em serviço ambulatorial; dentre os que ocorreram em serviços privados, 14,5% foram em hospital e 33,7% em clínicas. Pela análise multivariada, observou-se associação entre a utilização de serviços e sexo, presença de doenças, auto-percepção de saúde, interação da renda e escolaridade e posse de seguro saúde. A análise isolada com escolaridade apresentou efeito inverso. CONCLUSÕES: Foram observadas desigualdades no uso e acesso aos serviços de saúde e inadequação do modelo de atenção, indicando necessidade de políticas públicas que levem em conta as especificidades dessa população, facilitem o acesso e possam reduzir essas desigualdades.