Evaluation of the total antioxidant capacity of flavored water and electrochemical purine damage by sulfate radicals using a purine-based sensor

In this study, a method for the electrochemical quantification of the total antioxidant capacity (TAC) in beverages was developed. The method is based on the oxidative damage to the purine bases, adenine or guanine, that are immobilized on a glassy carbon electrode (GCE) surface. The oxidative lesions on the DNA bases were promoted by the sulfate radical generated by the persulfate/iron(II) system. The presence of antioxidants on the reactive system promoted the protection of the DNA bases immobilized on the GCE by scavenging the sulfate radical. Square-wave voltammetry (SWV) was the electrochemical technique used to perform this study. The efficiencies of five antioxidants (ascorbic acid, gallic acid, caffeic acid, coumaric acid and resveratrol) in scavenging the sulfate radical and, therefore, their ability to protect the purine bases immobilized on the GCE were investigated. These results demonstrated that the purine-based biosensor is suitable for the rapid assessment of the TAC in flavors and flavored water.

Avaliação de um escore clínico para rastreamento de suspeitos de tuberculose pulmonar

OBJETIVO: Avaliar acurácia de escore clínico (sensibilidade) no diagnóstico presuntivo de tuberculose pulmonar em triagem. MÉTODOS: Estudo descritivo-analítico transversal com 1.365 pacientes atendidos no setor de pneumologia em Unidade Básica de Saúde de nível secundário da cidade do Rio de Janeiro, RJ, de 2006 a 2007. Os participantes responderam um questionário padronizado, aplicado por equipe de enfermagem, contendo informações referentes à idade, peso e sintomas clínicos. O resultado presuntivo do diagnóstico de tuberculose pulmonar foi obtido pela soma da pontuação dos dados coletados. Diagnóstico de tuberculose ativa baseou-se nos resultados bacteriológicos e na decisão médica. Foram calculados sensibilidade, especificidade, valores preditivos positivos e negativos para uma prevalência especificada, e intervalos de 95% de confiança para diversos pontos de corte do escore. O desempenho do escore foi avaliado pela curva receiver operating characteristic (ROC). RESULTADOS: Para o diagnóstico de tuberculose, tosse > 1 semana e > 3 semanas mostrou sensibilidade respectivamente de 88,2% (86,2;90,2) e de 61,1% (57,93;64,3), especificidade de 19,2% (16,6;21,8) e 51,3% (48,1;54,5). O escore clínico com 8 pontos mostrou uma sensibilidade de 83,13% (77,8;87,6), especificidade de 51,8% (48,5;55,1), valor preditivo positivo de 91,6% (90,0;83,2) e negativo 32,9% (30,1;35,7). CONCLUSÕES: Tosse (> 3 sem) apresentou baixa sensibilidade e especificidade. Escore clínico com elevada sensibilidade pode ser uma ferramenta alternativa na detecção de tuberculose pulmonar, pois, além de agilizar o atendimento do caso suspeito na unidade, permite padronizar a primeira abordagem pela enfermagem.

Validation of a single-extraction procedure for sequential analysis of vitamin E, cholesterol, fatty acids, and total fat in seafood

Food lipid major components are usually analyzed by individual methodologies using diverse extractive procedures for each class. A simple and fast extractive procedure was devised for the sequential analysis of vitamin E, cholesterol, fatty acids, and total fat estimation in seafood, reducing analyses time and organic solvent consumption. Several liquid/liquid-based extractive methodologies using chlorinated and non-chlorinated organic solvents were tested. The extract obtained is used for vitamin E quantification (normal-phase HPLC with fluorescence detection), total cholesterol (normal-phase HPLC with UV detection), fatty acid profile, and total fat estimation (GC-FID), all accomplished in <40 min. The final methodology presents an adequate linearity range and sensitivity for tocopherol and cholesterol, with intra- and inter-day precisions (RSD) from 3 to 11 % for all the components. The developed methodology was applied to diverse seafood samples with positive outcomes, making it a very attractive technique for routine analyses in standard equipped laboratories in the food quality control field.

A filosofia da qualidade total aplicada a uma empresa do sector alimentar

Mestrado em Controlo de Gestão e dos Negócios

Fontes de fósforo total e o estado trófico de albufeiras em Portugal continental

O estudo realizado incidiu sobre 260 albufeiras, identificadas em diferentes fontes de informação e localizadas em Portugal continental. De entre as massas de água identificadas procedeu-se à classificação do estado trófico de 92 albufeiras, todas para as quais se dispõe de dados de qualidade da água para o efeito. Destas, de acordo com o critério de classificação adoptado em Portugal, 60 foram classificadas como eutróficas, em resultado principalmente das concentrações de fósforo total. Após a delimitação das bacias drenantes de 194 albufeiras, foram implementadas metodologias de quantificação de fósforo total afluente a essas massas de água. Com recurso a um modelo de balanço de massas foram simuladas as concentrações de fósforo total em 80 albufeiras, tendo sido considerados adequados os resultados obtidos em 42 albufeiras. Com base nos resultados obtidos concluiu-se que as metodologias de quantificação de fósforo total de origem urbana e de origem difusa são adequadas ao desenvolvimento de estudos de planeamento e de identificação das principais fontes de fósforo total, em águas doces superficiais.

Fatores de risco para absenteísmo com licença médica em trabalhadores da indústria de petróleo

OBJETIVO : Identificar fatores de risco para o absenteísmo com licença médica em trabalhadores de empresa de petróleo. MÉTODOS : Estudo caso-controle (120 casos e 656 controles) aninhado a um estudo de coorte retrospectivo com todos os trabalhadores de uma empresa de petróleo na Região Norte-Nordeste do Brasil entre 2007 e 2009. A variável resposta utilizada para representar o absenteísmo com licença médica foi a incidência média de faltas com licenças médicas no período, definida pela razão entre o total de dias de licenças médicas e os dias potencialmente trabalháveis no período. Análise de regressão logística foi utilizada para investigar a associação entre incidência média de faltas > 5,0% no período e as variáveis sexo, cargo, idade, tempo de atuação, regime de trabalho, tabagismo, hipertensão arterial, índice de massa corporal, atividade física, risco coronariano, sono, glicemia, diabetes não controlado, doença do aparelho cardiovascular, digestivo, aparelho locomotor, neurológica, neoplasia, posturas forçadas no trabalho, satisfação com o trabalho, relacionamento com a chefia e atenção concentrada no trabalho. RESULTADOS : A incidência média de faltas com licenças médicas > 5,0% no período da coorte foi 15,5%. O modelo logístico revelou que trabalhadores com incidência média de faltas > 5,0% tiveram 2,6 vezes mais chance de ser do sexo feminino; 2,0 vezes mais chance de ser fumante; 1,8 vez mais chance de ser ex-fumante, 2,2 vezes mais chance de relatar sono anormal e 10,5 vezes mais chance de estarem insatisfeitos com o trabalho do que trabalhadores com incidência média de faltas ≤ 5,0% no período. CONCLUSÕES : Sexo feminino, ser fumante ou ex-fumante, estar insatisfeito com o trabalho e relatar sono anormal são bons preditores de absenteísmo ao trabalho por doença.

Complemento hemolítico total, C3 e taxa de conversão de C3 nas formas cardíaca e indeterminada da doença de Chagas

Os valores de complemento hemolítico total, C3 total (nativo + produtos de degradação) e o grau de conversão de C3 nativo foram estudados em dois subgrupos de pacientes chagásicos, nas formas cardíaca e indeterminada, e em um subgrupo de indivíduos não chagásicos, clinicamente sadios. Os níveis de C3 total e as taxas de conversão de C3 em seus produtos de degradação foram semelhantes nos três subgrupos. Os valores de complemento hemolítico total foram estatisticamente diferentes nos três subgrupos (nível de significância descritivo p = 0,0757), tendo sido observada média aritmética mais baixa no subgrupo de cardíacos e mais elevada no subgrupo de controles. Maior amplitude de variação dos níveis de complemento hemolítico total foi notada no subgrupo de cardíacos, no qual se encontraram os valores extremos (máximo e mínimo), considerando-se todos os subgrupos.

Utilidad de las muestras de sangre total desecada en papel de filtro en la detección de anticuerpos antitoxoplasma

Se compara la técnica de Aglutinación Directa (AD) utilizando muestras de sangre total desecada en papel de filtro, con la técnica de ELISA y la misma AD utilizando muestras de suero de los mismos pacientes, para la detección de anticuerpos antitoxoplasma. Los resultados muestran la validez del método de la sangre desecada en papel de filtro para la detección de anticuerpos antitoxoplasma con la técnica de AD, y se considera su utilidad en los estudios epidemiológicos de campo.

Total serum IgE and parasite: specific IgG and IgA antibodies in human strongyloidiasis

Total serum IgE, and Strongyloides - specific IgG and IgA antibodies were studied in 27 patients with parasitologically proven strongyloidiasis. Clinical manifestations in this case series were investigated by a restrospective study of the patient's records. Total serum IgE levels were elevated (greater than 250 IU/ml) in 59% of the patients (mean concentration = 1364 IU/ml). Parasite - specific IgG and IgA antibodies were detected by ELISA in the serum of 23 (85.2%) and 21 (77.8%) patients, respectively. Elevated serum IgE and clinical manifestations were not useful indexes of the presence of strongyloidiasis. On the other hand, our results support the view that serologic tests, particularly ELISA for detecting Strongyloides - specific IgG antibodies, can be usefully exploited for diagnostic purposes in strongyloidiasis.

Intake of milk, but not total dairy, yogurt, or cheese, is negatively associated with the clustering of cardiometabolic risk factors in adolescents

Epidemiologic studies have reported an inverse association between dairy product consumption and cardiometabolic risk factors in adults, but this relation is relatively unexplored in adolescents. We hypothesized that a higher dairy product intake is associated with lower cardiometabolic risk factor clustering in adolescents. To test this hypothesis, a cross-sectional study was conducted with 494 adolescents aged 15 to 18 years from the Azorean Archipelago, Portugal. We measured fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body fat, and cardiorespiratory fitness. We also calculated homeostatic model assessment and total cholesterol/high-density lipoprotein cholesterol ratio. For each one of these variables, a z score was computed using age and sex. A cardiometabolic risk score (CMRS) was constructed by summing up the z scores of all individual risk factors. High risk was considered to exist when an individual had at least 1 SD from this score. Diet was evaluated using a food frequency questionnaire, and the intake of total dairy (included milk, yogurt, and cheese), milk, yogurt, and cheese was categorized as low (equal to or below the median of the total sample) or “appropriate” (above the median of the total sample).The association between dairy product intake and CMRS was evaluated using separate logistic regression, and the results were adjusted for confounders. Adolescents with high milk intake had lower CMRS, compared with those with low intake (10.6% vs 18.1%, P = .018). Adolescents with appropriate milk intake were less likely to have high CMRS than those with low milk intake (odds ratio, 0.531; 95% confidence interval, 0.302-0.931). No association was found between CMRS and total dairy, yogurt, and cheese intake. Only milk intake seems to be inversely related to CMRS in adolescents.

Total IgE detection in paired cerebrospinal fluid and serum samples from patients with neurocysticercosis

Neurocysticercosis (NC), the presence of Taenia solium metacestodes in tissues, is the most frequent and severe parasitic infection of the central nervous system. We investigated the presence of total IgE by an automated chemiluminescence assay in 53 paired cerebrospinal fluid (CSF) and serum samples from patients with NC (P) and in 40 CSF samples from individuals with other neurological disorders as the control group (C). Total IgE concentration ranged from 1.2 to 6.6 IU/ml (mean = 1.4 IU/ml, standard deviation-sd = 1.1 IU/ml) in 28.3% of CSF samples from the P group, a value significantly higher than for the C group (£1.0 IU/ml). The serum samples from the P group showed concentrations ranging from 1.0 to 2330.0 IU/ml (mean = 224.1 IU/ml, sd = 452.1 IU/ml), which were higher than the normal value cited by the manufacturer (<100.0 IU/ml) in 32.1% of the samples. A significant difference was observed in CSF samples from the P and C groups (p = 0.005) and in serum samples from the P group compared to the normal value (p = 0.005), with sera showing more frequent abnormal results.

O e-learning na manutenção industrial uma proposta de e-learning aplicada à manutenção produtiva total

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial

Assessing and comparing the total antioxidant capacity of commercial beverages: application to beers, wines, waters and soft drinks using TRAP, TEAC and FRAP methods.

This work measures and tries to compare the Antioxidant Capacity (AC) of 50 commercial beverages of different kinds: 6 wines, 12 beers, 18 soft drinks and 14 flavoured waters. Because there is no reference procedure established for this purpose, three different optical methods were used to analyse these samples: Total Radical trapping Antioxidant Parameter (TRAP), Trolox Equivalent Antioxidant Capacity (TEAC) and Ferric ion Reducing Antioxidant Parameter (FRAP). These methods differ on the chemical background and nature of redox system. The TRAP method involves the transfer of hydrogen atoms while TEAC and FRAP involves electron transfer reactions. The AC was also assessed against three antioxidants of reference, Ascorbic acid (AA), Gallic acid (GA) and 6-hydroxy-2,5,7,8-tetramethyl- 2-carboxylic acid (Trolox). The results obtained were analyzed statistically. Anova one-way tests were applied to all results and suggested that methods and standards exhibited significant statistical differences. The possible effect of sample features in the AC, such as gas, flavours, food colouring, sweeteners, acidity regulators, preservatives, stabilizers, vitamins, juice percentage, alcohol percentage, antioxidants and the colour was also investigated. The AC levels seemed to change with brand, kind of antioxidants added, and kind of flavour, depending on the sample. In general, higher ACs were obtained for FRAP as method, and beer for kind of sample, and the standard expressing the smaller AC values was GA.

The effect of method, standard and sample components on the total antioxidant capacity of commercial waters assessed by optical conventional assays

The total antioxidant capacity (TAC) of 28 flavoured water samples was assessed by ferric reducing antioxidant potential (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC) and total reactive antioxidant potential (TRAP) methods. It was observed that flavoured waters had higher antioxidant activity than the corresponding natural ones. The observed differences were attributed to flavours, juice and vitamins. Generally, higher TAC contents were obtained on lemon waters and lower values on guava and raspberry flavoured waters. Lower and higher TACs were obtained by TRAP and ORAC method, respectively. Statistical analysis suggested that vitamins and flavours increased the antioxidant content of the commercial waters.