11 resultados para 756

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) technique on a glassy carbon electrode is proposed. The electrochemical behavior of tetradifon as followed by cyclic voltammetry (CV) suggests that its reduction occurs via an irreversible five-electron transfer vs. Ag vertical bar AgCl, KCl 3 M reference electrode. Very well-resolved diffusion controlled voltammetric peaks have been obtained in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L-1 at -1.43, -1.57, -1.73, -1.88, and -2.05 V. The proposed DPV method has a good linear response in the 3.00 - 10.0 mu mol L-1 range, with a limit of detection (L.O.D) of 0.756 mu mol L-1 and 0.831 mu mol L-1 in the absence and in the presence of the matrix, respectively. Moreover, improved L.O.D results (0.607 mu mol L-1) have been achieved in the absence of DMF from the supporting electrolyte solution. Recovery has been evaluated in five commercial green bell pepper samples, and recovery percentages ranging from 91.0 to 109 have been obtained for tetradifon determinations. The proposed voltammetric method has also been tested for reproducibility, repeatability, and potential interferents, and the results obtained for these three analytical parameters are satisfactory for electroanalytical purposes. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.024207jes] All rights reserved.

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The scope of this study was to estimate the prevalence of overweight and obesity and its association with socio-economic status in a sample of non-institutionalized elderly people from Vitoria-ES, Brazil. This was a cross-sectional survey with a sample of 882 elderly people aged 60 and over. Obesity and overweight were assessed using the body mass index (BMI) and waist circumference (WC). All subjects answered a personal and socio-demographic questionnaire in relation to age, gender, marital status, physical activity, number of children, chronic diseases and smoking. Associations between categorical variables were tested using chi-square analysis with a 5% significance level. The prevalence of overweight and obesity was high (41.8% and 23.4%, respectively) and 50.7% of the elderly had a substantially increased waist circumference. About 4.3% of the individuals had diabetes, 50.4% had hypertension and 14.9% were found to have both diseases. It was observed that both the BMI and WC were significant associated (p<0.05) with sex, marital status, the presence of diseases and with cigarette smoking.

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The non-classical human leukocyte antigen (HLA) class I genes present a very low rate of variation. So far, only 10 HLA-E alleles encoding three proteins have been described, but only two are frequently found in worldwide populations. Because of its historical background, Brazilians are very suitable for population genetic studies. Therefore, 104 bone marrow donors from Brazil were evaluated for HLA-E exons 14. Seven variation sites were found, including two known single nucleotide polymorphisms (SNPs) at positions +424 and +756 and five new SNPs at positions +170 (intron 1), +1294 (intron 3), +1625, +1645 and +1857 (exon 4). Haplotyping analysis did show eight haplotypes, three of them known as E*01:01:01, E*01:03:01 and E*01:03:02:01 and five HLA-E new alleles that carry the new variation sites. The HLA-E*01:01:01 allele was the predominant haplotype (62.50%), followed by E*01:03:02:01 (24.52%). Selective neutrality tests have disclosed an interesting pattern of selective pressures in which balancing selection is probably shaping allele frequency distributions at an SNP at exon 3 (codon 107), sequence diversity at exon 4 and the non-coding regions is facing significant purifying pressure. Even in an admixed population such as the Brazilian one, the HLA-E locus is very conserved, presenting few polymorphic SNPs in the coding region.

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The aim of the present study was to examine whether children with motor difficulties would show levels of health-related components of physical fitness lower than children without such difficulties. Sixteen children with motor difficulties with approximately 8 years of age were age-and gender-matched with other 16 children without motor difficulties. Participants completed the test batteries for physical fitness (seat and reach, standing long jump, sit-up, modified pull-up and 9-minute run) and for motor coordination (MABC-2). The results indicated significant differences in standing long jump, sit-up, modified pull-up tests, but not for the seat and reach and the 9-minute run tests. Overall, the results are similar to those published in the international literature, with the exception of cardiorespiratory fitness. The idea that at to some degree coordination is required to perform physical fitness tasks and might impact on physical fitness performance is further discussed in the present work.

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The herbicides glyphosate and paraquat have been used by Brazilian soybean producers to obtain crop desiccation and to anticipate and uniformity at harvest. However, improper use of herbicides can to occasion problems in agronomic and physiologic characteristics of crop. This study aimed to evaluate the use of the glyphosate and paraquat herbicides as a desiccant for growing soybeans. The experiment was conducted in 2005/06 crop year, in an experimental design of randomized blocks with four replications. Treatments were arranged in two factorial design, 3x3x5x2 and 3x2x5x2: two desiccants (glyphosate and paraquat) and control (without drying), three and two growth stages (R6, R7 and R8) and (R7 and R8) for varieties MSOY 6101 of superprecocious cycle, and MG / BR 46 (Conquista) of precocious cycle, respectively, five sampling times (2, 4, 6, 8 and 10 days after application) and two positions in the plants on the ground assessment (apex and base). Was evaluated for seed Production, mass and water content of 100 seeds. Desiccants tested were effective in reducing the water content of seeds, without affecting productivity and mass of 100 seeds.

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Be stars possess gaseous circumstellar disks that modify in many ways the spectrum of the central B star. Furthermore, they exhibit variability at several timescales and for a large number of observables. Putting the pieces together of this dynamical behavior is not an easy task and requires a detailed understanding of the physical processes that control the temporal evolution of the observables. There is an increasing body of evidence that suggests that Be disks are well described by standard alpha-disk theory. This paper is the first of a series that aims at studying the possibility of inferring several disk and stellar parameters through the follow-up of various observables. Here we study the temporal evolution of the disk density for different dynamical scenarios, including the disk buildup as a result of a long and steady mass injection from the star, the disk dissipation that occurs after mass injection is turned off, as well as scenarios in which active periods are followed by periods of quiescence. For those scenarios, we investigate the temporal evolution of continuum photometric observables using a three-dimensional non-LTE radiative transfer code. We show that light curves for different wavelengths are specific of a mass loss history, inclination angle, and alpha viscosity parameter. The diagnostic potential of those light curves is also discussed.

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In order to assess the contribution of different parenteral routes as risk exposure to the hepatitis C virus (HCV), samples from nine surveys or cross-sectional studies conducted in two Brazilian inland regions were pooled, including a total of 3,910 subjects. Heterogeneity among the study results for different risk factors was tested and the results were shown to be homogeneous. Anti-HCV antibodies were observed in 241 individuals, of which 146 (3.7%, 95% CI?=?3.24.4) had HCV exposure confirmed by immunoblot analysis or PCR test. After adjustment for relevant variables, a correlation between confirmed HCV exposure and injection drug use, tattooing, and advance age was observed. In a second logistic model that included exposures not searched in all nine studies, a smaller sample was analyzed, revealing an independent HCV association with past history of surgery and males who have sex with other males, in addition to repeated injection drug use. Overall, these analyses corroborate the finding that injection drug use is the main risk factor for HCV exposure and spread, in addition to other parenteral routes. J. Med. Virol. 84:756762, 2012. (C) 2012 Wiley Periodicals, Inc.

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The endophytic fungus Epicoccum nigrum was isolated from sugarcane and the bioguided fractionation of the ethyl acetate extract led to the isolation of epicolactone, mellein, and 4,5-dimethylresorcinol. Characterization of epicolactone by MS, NMR and X-ray crystallography revealed a new natural product with an unusual carbon skeleton. The production of this secondary metabolite decreased in mutants of Epicoccum nigrum transformed by Agrobacterium tumefaciens. Additionally, these mutants produced 4-hydroxymellein.

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O presente trabalho propõe uma revisão de epidemiologia, patogênese, quadro clínico, diagnóstico e tratamento da espondilite anquilosante e sua associação com alteração ocular com a devida condução da doença e suas manifestações. Os autores utilizaram em sua pesquisa os bancos de dados PubMed (MEDLINE), LILACS e Biblioteca do Centro de Estudos de Oftalmologia. A espondilite anquilosante é uma doença inflamatória crônica que acomete preferencialmente o esqueleto axial, podendo evoluir com rigidez e limitação funcional progressiva. Seu início costuma ocorrer por volta da segunda à terceira década de vida, preferencialmente em indivíduos do gênero masculino, caucasianos e HLA-B27-positivos. Sua etiologia e patogênese não são completamente elucidadas, e seu diagnóstico costuma ser tardio. O controle clínico e o tratamento são frequentemente satisfatórios.A uveíte anterior aguda é a manifestação extra-articular mais comum, ocorrendo em cerca de 20%-30% dos pacientes com espondilite anquilosante. Aproximadamente metade dos casos de uveíte anterior aguda está associada à presença do antígeno HLA-B27, podendo ser a primeira manifestação de uma doença reumatológica não diagnosticada, geralmente com boa resposta terapêutica e bom prognóstico. Concluímos que, para melhor avaliação e tratamento dos pacientes com uveíte, é importante maior integração entre oftalmologistas e reumatologistas.

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The scope of this study was to estimate the prevalence of overweight and obesity and its association with socio-economic status in a sample of non-institutionalized elderly people from Vitória-ES, Brazil. This was a cross-sectional survey with a sample of 882 elderly people aged 60 and over. Obesity and overweight were assessed using the body mass index (BMI) and waist circumference (WC). All subjects answered a personal and socio-demographic questionnaire in relation to age, gender, marital status, physical activity, number of children, chronic diseases and smoking. Associations between categorical variables were tested using chi-square analysis with a 5% significance level. The prevalence of overweight and obesity was high (41.8% and 23.4%, respectively) and 50.7% of the elderly had a substantially increased waist circumference. About 4.3% of the individuals had diabetes, 50.4% had hypertension and 14.9% were found to have both diseases. It was observed that both the BMI and WC were significant associated (p<0.05) with sex, marital status, the presence of diseases and with cigarette smoking.

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O presente estudo tem como objetivo analisar se crianças com dificuldades motoras apresentariam baixos níveis de aptidão física relacionada à saúde em relação aos seus pares sem dificuldades. Dezesseis crianças com dificuldades motoras com aproximadamente oito anos foram pareadas em gênero e idade com outras 16 sem dificuldades motoras. Os participantes completaram os testes de aptidão física (sentar e alcançar, salto em distância parado, puxada em suspensão na barra modificado, abdominal e corrida de 9 minutos) e os de coordenação motora (MABC-2). Os resultados indicaram diferenças significativas no salto em distância parado, puxada em suspensão na barra modificado, abdominal, mas não para sentar e alcançar e corrida de 9-m. Os resultados são semelhantes aos publicados na literatura internacional, com exceção da corrida de 9 minutos. A ideia de que em algum grau a coordenação é necessária para executar tarefas de aptidão física e pode impactar no desempenho da aptidão física é discutida no presente trabalho.