914 resultados para Three Factor Model
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The aim of this study was to adapt the BriefCOPE Inventory for Portuguese-speaking university students. We evaluate the Portuguese BriefCOPE psychometrics qualities and estimated the BriefCOPE factorial invariance in Brazil and Portugal. The data collected from a sample of 1573 students of both nationalities did confirm the 14-factor structure of the BriefCOPE and showed both factorial, convergent and discriminant related validities. However, the factor model did not show invariance across countries indicating that the use of the Portuguese version of the BriefCOPE cannot be bailed for comparisons of scores of inter-countries' student coping.
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Aim: To estimate the reliability and validity of the Dental Anxiety Scale (DAS) and identify the prevalence and the effect of the socio-demographic characteristics of dental anxiety, in a sample of 212 adults. Methods: The psychometric sensitivity of the scale was assessed. A confirmatory factor analysis was performed, and the convergent validity and internal consistency were determined. The prevalence of anxiety was estimated, and the effect of socio-demographic variables on anxiety was assessed using structural equation modelling. Results: The participants’ mean age was 33.5 (SD = 15.6) years, and 62.3% were female. There was an adequate factorial adjustment of the scale in this sample. The convergent validity and internal consistency were adequate in the one-factor model. Regarding two-factor model, there was a high correlation (r) among the factors, which jeopardized the discriminant validity. A total of 47.6% of the participants (IC95% = 40.9 - 54.4) presented low levels of anxiety, 32.5% (IC95% = 26.2 - 38.9) moderate levels, and 12.3% (IC95% = 7.8 - 16.7) exacerbated levels. There was a non-significant effect of gender, age and education on the anxiety levels of this sample. Conclusion: We concluded that the one-factor model presented better psychometric qualities, that anxiety was highly prevalent and there was no significant effect of the demographic variables on anxiety, in this sample
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The stability of the Glossoscolex paulistus hemoglobin (HbGp), in two iron oxidation states (and three forms), as monitored by optical absorption, fluorescence emission and circular dichroism (CD) spectroscopies, in the presence of the chaotropic agent urea, is studied. HbGp oligomeric dissociation, denaturation and iron oxidation are observed. CD data show that the cyanomet-HbGp is more stable than the oxy-form. Oxy- and cyanomet-HbGp show good fits on the basis of a two state model with critical urea concentrations at 220-222 nm of 5.1 +/- 0.2 and 6.1 +/- 0.1 mol/L, respectively. The three-state model was able to reveal a subtle second transition at lower urea concentration (1.0-2.0 mol/L) associated to partial oligomeric dissociation. The intermediate state for oxy- and cyanomet-HbGp is very similar to the native state. For met-HbGp, a different equilibrium, in the presence of urea, is observed. A sharp transition at 1.95 +/- 0.05 mol/L of denaturant is observed, associated to oligomeric dissociation and hemichrome formation. In this case, analysis by a three-state model reveals the great similarity between the intermediate and the unfolded states. Analysis of spectroscopic data, by two-state and three-state models, reveals consistency of obtained thermodynamic parameters for HbGp urea denaturation. (C) 2012 Elsevier Inc. All rights reserved.
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Functionalization with surfactants and with active molecules of deoxyribonucleic acid (DNA), thin film processing as well as their nonlinear optical and electrical properties are reviewed and discussed. On the basis of a quantum three level model, we show that the anomalous concentration variation of cubic susceptibility chi((3))(-3 omega; omega, omega, omega) in thin films of DNA-CTMA complexes doped with Disperse Red 1 chromophore can be explained by the concentration variation of two-photon resonance contribution. We show also that the DNA complexes, plasticized with glycerol and adequately doped can be processed into self standing conducting membranes with a high electrical conductivity. The measured ionic conductivity at room temperature, depending on dopant used and its concentration, is in the range of 3.5 x 10(-4)-10(-5) S/cm and increases linearly as a function of temperature, reaching 10(-3) S/cm at 358 K for the most conducting sample, obeying predominantly the Arrhenius law. Practical applications of DNA complexes are also described and discussed. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
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This work aimed at evaluating the spray congealing method for the production of microparticles of carbamazepine combined with a polyoxylglyceride carrier. In addition, the influence of the spray congealing conditions on the improvement of drug solubility was investigated using a three-factor, three-level Box-Behnken design. The factors studied were the cooling air flow rate, atomizing pressure, and molten dispersion feed rate. Dependent variables were the yield, solubility, encapsulation efficiency, particle size, water activity, and flow properties. Statistical analysis showed that only the yield was affected by the factors studied. The characteristics of the microparticles were evaluated using X-ray powder diffraction, scanning electron microscopy, differential scanning calorimetry, and hot-stage microscopy. The results showed a spherical morphology and changes in the crystalline state of the drug. The microparticles were obtained with good yields and encapsulation efficiencies, which ranged from 50 to 80% and 99.5 to 112%, respectively. The average size of the microparticles ranged from 17.7 to 39.4 mu m, the water activities were always below 0.5, and flowability was good to moderate. Both the solubility and dissolution rate of carbamazepine from the spray congealed microparticles were remarkably improved. The carbamazepine solubility showed a threefold increase and dissolution profile showed a twofold increase after 60 min compared to the raw drug. The Box-Behnken fractional factorial design proved to be a powerful tool to identify the best conditions for the manufacture of solid dispersion microparticles by spray congealing.
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The aim of the present study was to obtain microparticles of hydrochlorothiazide, a diuretic drug that practically insoluble in water, by spray drying and to investigate the influence of process parameters using a three-level, three-factor Box-Behnken design. Process yields, moisture content, particle size, flowability, and solubility were used to evaluate the spray-dried microparticles. The data were analyzed by response surface methodology using analysis of variance. The independent variables studied were outlet temperature, atomization pressure, and drug content. The formulations were prepared using polyvinylpyrrolidone and colloidal silicon dioxide as the hydrophilic carrier and drying aid, respectively. The microparticle yield ranged from 18.15 to 59.02% and resulted in adequate flow (17 to 32 degrees), moisture content between 2.52 to 6.18%, and mean particle size from 45 to 59 mu m. The analysis of variance showed that the factors studied influenced the yields, moisture content, angle of repose, and solubility. Thermal analysis and X-ray diffractometry evidenced no drug interactions or chemical modifications. Photomicrographs obtained by scanning electron microscopy showed spherical particles. The solubility and dissolution rates of hydrochlorothiazide were remarkably improved when compared with pure drug. Therefore, the results confirmed the high potential of the spray-drying technique to obtain microparticulate hydrochlorothiazide with enhanced pharmaceutical and dissolution properties.
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Betanin is a natural pigment with antioxidant properties used as a food colourant. This work describes the spectrophotometric and chromatographic quantification of betanin (2S/15S) and its epimer isobetanin (2S/15R) in fresh beetroot juice, food-grade beetroot powder and betanin standard diluted in dextrin. Absorption spectra of all three samples were deconvoluted using a mixed three-function model. Food-grade beetroot powder has the largest amount of violet-red impurities, probably formed during processing. The purification of betanin from these complex matrices was carried out by seven different methods. Ion exchange chromatography was the most efficient method for the purification of betanin from all samples; however, fractions contain high amounts of salt. Reversed-phase HPLC as well as reversed-phase column chromatography also produced good results at a much faster rate. The longer retention time of isobetanin when compared to betanin in reversed-phase conditions has been investigated by means of quantum-mechanical methods. (C) 2011 Elsevier Ltd. All rights reserved.
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Este artigo versa sobre uma pesquisa integrante do Núcleo de Apoio à Pesquisa em Estudos de Linguagem em Arquitetura e Cidade (N.ELAC), que desenvolve pesquisas em Linguagem e Representação. Entre as diversas formas de representação em arquitetura, a presente pesquisa traz o modelo tridimensional físico como ferramenta que proporciona maior facilidade de leitura do projeto, sendo mais concreta que os desenhos técnicos. Objetiva-se, assim, destacar a importância do modelo físico como meio de aproximação da população ao patrimônio arquitetônico. Como estudo de caso, foi escolhido o Edifício E1, obra de Ernest Mange e Hélio Duarte. Localizado no campus da USP em São Carlos, é considerado patrimônio da cidade, entretanto, encontra-se praticamente enclausurado no interior do campus, dificultando maior contato da comunidade com o edifício. O projeto do edifício utilizou apenas o desenho como representação, não incluindo nenhum tipo de modelo tridimensional (físico ou digital). A partir de um levantamento das representações gráficas utilizadas pelos projetistas, foi possível fazer uma comparação entre o nível de compreensão do projeto apenas com as peças gráficas dos arquitetos e a partir do modelo físico, produzido pela pesquisadora. Foi realizado um pré-teste em escola pública municipal, despertando o interesse desses alunos pelo edifício em questão.
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O presente artigo vincula-se às pesquisas do Núcleo de Apoio à Pesquisa em Estudos de Linguagem em Arquitetura e Cidade (N.ELAC), que atua na área de Linguagem e Representação. Diante das diversas formas de representação em arquitetura (desenho, maquete, modelos digitais), nesta pesquisa o modelo tridimensional físico é trazido como ferramenta que proporciona maior facilidade de leitura do projeto e tratado como meio de aproximação da comunidade ao patrimônio arquitetônico, envolvendo, sobretudo, a arquitetura moderna paulista. Como estudo de caso, escolheu-se o Edifício E1, obra de Ernest Mange e Hélio Duarte. Localizado no campus da USP em São Carlos, é considerado patrimônio da cidade, entretanto, encontra-se praticamente enclausurado no interior do campus, dificultando maior contato da comunidade com o edifício. Durante sua execução, foi utilizado apenas o desenho como ferramenta de representação de projeto, não incluindo nenhum tipo de modelo tridimensional (físico ou digital). A partir do levantamento das representações gráficas utilizadas, foi possível fazer uma comparação entre o nível de compreensão do projeto apenas com as peças gráficas dos arquitetos e a partir do modelo físico, produzido pela pesquisadora. Realizou-se um pré-teste em escola pública municipal, que indicou um aumento no interesse desses alunos pelo edifício em questão.
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Durante o processo de projeto, o arquiteto transpõe suas ideias para o campo real, do concreto. Os diversos modos de expressão e representação têm como função mediar essa interação, diminuindo a distância entre esses dois campos. Vive-se hoje, um momento de intensa transformação das estratégias projetuais, propiciada pelos novos meios digitais. Assim, esta pesquisa, centra-se na comparação entre diversos momentos do uso de modelos nos processos projetivos contemporâneos, através de uma investigação em escritórios de arquitetura paulistanos que utilizam o modelo físico como parte de seus processos de projeto. Busca-se entender qual o papel dessa ferramenta de representação e suas potencialidades nos dias atuais. Como estudo de caso, faz-se uma análise comparativa entre o uso das maquetes digital e física, destacando dois estudos: a maquete do Conjunto Ponte dos Remédios, do arquiteto Marcos Acayaba e as maquetes de estudos elaboradas pelo escritório Andrade Morettin Arquitetos, para o concurso para o Instituto Moreira Salles/SP. Entre os objetivos desse trabalho também se encontra uma análise da contribuição dos modelos físicos no Ensino de Arquitetura.
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Durante o processo de projeto, o arquiteto transpõe suas ideias para o campo real, do concreto. Os diversos modos de expressão e representação têm como função mediar essa interação, diminuindo a distância entre esses dois campos. Vive-se hoje, um momento de intensa transformação das estratégias projetuais, propiciadas pelos novos meios digitais. Esta pesquisa tem como objetivo o estudo do uso das representações tridimensionais, especificamente dos modelos físicos e digitais. Pretende-se flagrar os momentos contributivos dos modelos no processo projetivo e as características intrínsecas a eles. A discussão busca não apenas destacar a importância dessa ferramenta, como também, traçar uma breve comparação entre a tecnologia digital e a feitura manual. Para este trabalho foram selecionados alguns arquitetos significativos do cenário da arquitetura paulista em cujos projetos comparecem o uso de modelos. Como estudos de caso tem-se a Residência do arquiteto Marcos Acayaba e o projeto vencedor do Concurso para o Instituto Moreira Salles/ SP, do escritório Andrade Morettin Arquitetos. Soma-se a estes objetivos, a apresentação do uso de modelos físicos e digitais em uma experiência didática projetiva.
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Maintaining the postharvest quality of whole and fresh-cut fruit during storage and distribution is the major challenge facing fruit industry. For this purpose, industry adopt a wide range of technologies to enable extended shelf-life. Many factors can lead to loss of quality in fresh product, hence the common description of these products as ‘perishable’. As a consequence normal factors such as transpiration and respiration lead ultimately to water loss and senescence of the product. Fruits and vegetables are living commodities and their rate of respiration is of key importance to maintenance of quality. It has been commonly observed that the greater the respiration rate of a product, the shorter the shelf-life. The principal problem for fresh-cut fruit industries is the relative shorter shelf-life of minimally processed fruit (MPF) compared to intact product. This fact is strictly connected with the higher ethylene production of fruit tissue stimulated during fresh-cut processing (peeling, cutting, dipping). 1-Methylcyclopropene (1-MCP) is an inhibitor of ethylene action and several researches have shown its effectiveness on the inhibition of ripening and senescence incidence for intact fruit and consequently on their shelf-life extension. More recently 1-MCP treatment has been tested also for shelf-life extension of MPF but discordant results have been obtained. Considering that in some countries 1-MCP is already a commercial product registered for the use on a number of horticultural products, the main aim of this actual study was to enhance our understanding on the effects of 1-MCP treatment on the quality maintenance of whole and fresh-cut climacteric and non-climacteric fruit (apple, kiwifruit and pineapple). Concerning the effects of 1-MCP on whole fruit, was investigated the effects of a semi-commercial postharvest treatment with 1-MCP on the quality of Pink Lady apples as functions of fruit ripening stage, 1-MCP dose, storage time and also in combination with controlled atmospheres storage in order to better understand what is the relationship among these parameters and if is possible to maximize the 1-MCP treatment to meet the market/consumer needs and then in order to put in the market excellent fruit. To achieve this purpose an incomplete three-level three-factor design was adopted. During the storage were monitored several quality parameters: firmness, ripening index, ethylene and carbon dioxide production and were also performed a sensory evaluations after 6 month of storage. In this study the higher retention of firmness (at the end of storage) was achieved by applying the greatest 1-MCP concentration to fruits with the lowest maturity stage. This finding means that in these semi-commercial conditions we may considerate completely blocked the fruit softening. 1-MCP was able to delay also the ethylene and CO2 production and the maturity parameters (soluble solids content and total acidity). Only in some cases 1-MCP generate a synergistic effect with the CA storage. The results of sensory analyses indicated that, the 1-MCP treatment did not affect the sweetness and whole fruit flavour while had a little effect on the decreasing cut fruit flavour. On the contrary the treated apple was more sour, crisp, firm and juicy. The effects of some treatment (dipping and MAP) on the nutrient stability were also investigated showing that in this case study the adopted treatments did not have drastic effects on the antioxidant compounds on the contrary the dipping may enhance the total antioxidant activity by the accumulation of ascorbic acid on the apple cut surface. Results concerning the effects of 1-MCP in combination with MAP on the quality parameters behaviour of the kiwifruit were not always consistent and clear: in terms of colour maintenance, it seemed to have a synergistic effect with N2O MAP; as far as ripening index is concerned, 1-MCP had a preservative effect, but just for sample packed in air.