Cost-effective composite electrode for the fast voltammetric screening and determination of riboflavin (B2) and pyridoxine (B6) in pharmaceuticals

Different solid composites made by mechanical dispersions of graphite particles into heated paraffin (from 65 to 80% graphite, in mass) were prepared and assessed in order to optimize their use in electrochemical and electroanalytical procedures for bioanalysis. Besides these, composites were also evaluated by thermoanalytical techniques aiming to study their conservation and long-term stability (over eight months without special care), among others. Best results were found at 80% m/m graphite in paraffin. Such electrode combines low-cost, stability, sensitivity, ease of maintenance and clearance, besides the possibilities of manufacture in many different forms and shapes (with or without modifications) and applicability in a wide range of pH. Electrochemical studies by different voltammetric techniques involving vitamins from complex B (riboflavin and pyridoxine) leaded to a better understanding about their electrooxidative processes onto carbon-composite electrodes, specially regarding reversibility and pH-dependence. Data were also acquired and optimized with analytical purposes, being square-wave voltammetry in pH 4.2 chosen by its many advantages. Good linearity between peak responses as function of concentration were reached from 5 to 43 μmol L-1 for riboflavin (peak at -0.257 V) and up to 8.5 × 10-4 mol L -1 for pyridoxine (peak at +1.04 V), best studied conditions; limits of detection (at an S/N of 3) for both analites showed to be circa 1.0 mol L-1. Different commercial samples were analyzed for riboflavin (EMS® complex B syrup) and pyridoxine (Citoneurin 5000 Merck® ampoules) providing 96.6% and 98.7% recoveries, respectively.

Nutritional intake according to injury extent in ulcerative colitis patients

Background: Ulcerative colitis (UC) is often associated with nutritional deficiency, which appears to contribute to the progression of UC severity. The present study aimed to evaluate nutritional status and dietary intake in UC remission patients. Methods: The present study comprised a cross-sectional study in which variables such as extent of disease (distal colitis, left-sided colitis, pancolitis), remission period, sex and age were recorded. Extent of disease was assessed by the results of a colonoscopy and dietary intake was evaluated by using 3-day, 24-h recalls. A Kruskall-Wallis test was used to compare the intake of macro- and micronutrients among the three study groups. The analysis was complemented by the Mann-Whitney test. A logistic regression analysis was performed to identify predictive factors of extent of disease (pancolitis versus left-sided colitis versus distal colitis). Results: The median (range) age of the 59 patients was 49.0 (37.0-63.0) years and 53.3% were female. Twenty-six (44.1%) patients had distal colitis, 11 (18.6%) patients had left-sided colitis and 22 (37.3%) patients had pancolitis. A high probability of an inadequate intake of fibre (100%), fat soluble vitamins (>40% for vitamin A and >95% for vitamin E), vitamin C (>34%), calcium (>90%) and magnesium (>50%) was identified in the study group. Vitamin D intake (odds ratio = 0.60; 95% confidence interval = 0.39-0.94; P < 0.05) was significantly associated with increased intestinal damage. Conclusions: A large number of individuals showed an inadequate intake of nutrients. In addition, the consumption of vitamin D was significantly associated with extent of disease. © 2013 The British Dietetic Association Ltd.

Técnicas para acúmulo em plantas de substâncias fotossintetizantes de uso em terapia fotodinâmica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atividade de enzimas digestivas de Lithobates catesbeianus durante o desenvolvimento larval

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização bioquímica e centesimal das espécies Astrocaryum vulgare Mart. (tucumã) e Endopleura uchi (Huber) Cuatrec. (uxi) nativas da região Amazônica

Pós-graduação em Biotecnologia - IQ

Avaliação de caracteristicas físico-químicas e bioquímicas do pequi (Caryocar brasiliense Camb.) em suas diversas formas de armazenamento

Pós-graduação em Biotecnologia - IQ

O emprego da metodologia de superfície de resposta no desenvolvimento de um novo produto simbiótico, fermentado com Enterococcus faecium CRL 183 e Lactobacillus helveticus ssp jugurti 416, à base de extratos aquosos de soja e de Yacon (Smallanthus sonchifolius)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade microbiológica e ocorrência de leveduras em leite pasteurizado tipos A, B e C

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da variedade e região de cultivo sobre compostos bioativos, atividade antioxidante e cor de laranjas de polpa vermelha

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ácido fólico: validação do método espectrofotométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização para a obtençao de extrato aquoso de tremoço branco (Lupinus albus L.) adicionado de suco de pitanga

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da composição química, compostos bioativos e atividade antioxidante em cogumelos comestíveis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da desidratação por spray dryng sobre o teor ácido ascórbico no suco de acerola (Malpighia ssp)

Pós-graduação em Alimentos e Nutrição - FCFAR

Indicadores nutricionais e níveis de homocisteína em pacientes com doença arterial periférica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de parâmetros fisiológicos e bioquímicos em berinjela (Solanum melongena L.) cultivada sob diferentes potenciais de água no solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)