288 research outputs found

    Analysis of Factors Involving Drinking Water Contamination by Glyphosate and/or Nitrate in Urban Areas

    Get PDF
    This study investigated factors that could be related to drinking water contamination in urban areas in order to obtain quality profiles that characterized presence of the glyphosate and nitrate contaminants. Thus, in a period of one year, 4,853 tap water samples from 89 cities in the northeastern region of the State of São Paulo, Brazil, were analyzed in 21 physicochemical and 2 microbiological parameters. Additionally, 4 demographic variables were also included in multivariate data analysis. Principal Component Analysis of physicochemical and microbiological data showed that glyphosate concentration is positively correlated with nitrate concentration, especially in cities that make exclusive use of groundwater, besides correlating with conductivity and with concentrations of calcium, magnesium, fluoride, chloride, phosphate and free residual chlorine. The inclusion of demographic variables in Principal Component Analysis did not significantly change waters physicochemical profiles, but in cities that exclusive use groundwater for public supply the number of hospitalizations for diarrhea correlated positively with glyphosate, nitrate and chloride concentrations, in addition to conductivity. Linear Discriminant Analysis models involving 5 variables (conductivity and concentrations of calcium, magnesium, chloride and nitrate) were able to predict the cities vulnerability to groundwater contamination by nitrate

    Editorial: Hypoxia and Cardiorespiratory Control

    Get PDF
    To maintain adequate oxygen levels in the body, which is essential for a healthy life, the respiratory and cardiovascular systems play vitally important roles. When the oxygen content is insufficient, i.e., when hypoxia is loaded, respiratory and cardiovascular systems respond to restore, compensate, or adapt to hypoxia, e.g., by increasing ventilation and blood flow to maintain oxygen transport to vital organs. Traditionally, it has been thought that hypoxia is detected solely by carotid and aortic bodies, i.e., by peripheral chemoreceptors, and information from the peripheral chemoreceptors is transmitted to respiratory and cardiovascular centers in the brainstem whose respiratory and cardiovascular neural outputs are regulated. However, recent progress in neurophysiology has clarified that there are hypoxia-sensors not only in the periphery but also in the central nervous system. Hypoxia also affects the vascular system causing atherosclerosis and pulmonary hypertension and impairs blood glucose regulation that also facilitates atherosclerosis. The effects of hypoxia on vital organs and tissues vary depending on the modality of hypoxia exposure, i.e., acute, chronically sustained, or intermittent hypoxia. Although these issues have been vigorously investigated, the underlying mechanisms are yet to be unraveled. Likewise, long-range consequences for organ and tissue functions affected by hypoxia have not been fully elucidated. In the article collection of this Research Topic, a series of studies report the latest and most notable pathophysiological findings that are categorized into four areas: respiratory control, glucose metabolism, pulmonary hypertension, and sympathetic nervous system activation. The articles attempt to clarify many of the unsolved issues summarized below. (Introduction

    Simulation study of electron drift and gas multiplication in Micro Pixel Chamber

    Full text link
    The physical processes of charge collection and gas multiplication of a Micro Pixel Chamber (mu-PIC) were studied in detail using a three-dimensional simulation. The collection efficiencies of primary electrons and gas multiplication factors were calculated for several electrode structures. Based on those studies, we analyzed the optimization of the electrode structure of the mu-PIC, in order to obtain a high gas gain of more than 10^4 and a simultaneous suppression of discharges. Consequently, we found that these characteristics strongly depend on the substrate thickness and the anode diameter of the mu-PIC. In addition, a gas gain of 10^5 would be expected for a mu-PIC having a thick substrate of > 150um.Comment: 16 pages, 14 figures, Submitted to Nucl. Instr. Methods

    Parâmetros físico-químicos incomuns em água de abastecimento público de um município da região nordeste do Estado de São Paulo (Brasil)

    Get PDF
    Public water supply samples (n = 4347) from 88 municipalities in the northeast of the State of São Paulo (Brazil) were analysed in 21 physico-chemical parameters: temperature, conductivity (by conductimetry), free residual chlorine (colorimetry with N,N-diethyl-p-phenylenediamine), pH (potentiometry), apparent color (spectrophotometry), turbidity (nephelometry), and concentrations of Li+, Na+, NH4+, K+, Ca2+, Mg2+, F-, ClO2-, BrO3-, Cl-, Br-, ClO3-, NO3-, PO43-, SO42- (ion chromatography). The results were submitted to multivariate data analysis. The principal component analysis of 12 variable medians (pH, conductivity, Li+, Na+, K+, Ca2+, Mg2+, Cl-, ClO3-, NO3-, PO43-, SO42-) from 88 municipalities indicated Ibitinga as the locality with the public water supply having physicochemical characteristics unique in the region, characterized by higher relative concentrations of sulphate, chloride, lithium, and sodium, and higher values of pH and conductivity. Additionally, Ibitinga was the only municipality that systematically presented bromide in the water composition. A second principal component analysis on 79 samples of Ibitinga has indicated a sample with higher concentrations of chloride and sulphate, and 4 samples where the presence of nitrate was characteristic. Hierarchical cluster analysis exhibited the clustering of these groups produced in two component analysis. Validation of methods based on ion chromatography is also presented.Amostras de águas de abastecimento público (n = 4347) de 88 municípios do nordeste do Estado de São Paulo (Brasil) foram analisadas em 21 parâmetros físico-químicos: temperatura, condutividade (por condutimetria), cloro residual livre (colorimetria com N,N-dietil-p-fenilenodiamina), pH (potenciometria), cor aparente (espectrofotometria), turbidez (nefelometria), e concentrações de Li+, Na+, NH4+, K+, Ca2+, Mg2+, F-, ClO2-, BrO3-, Cl-, Br-, ClO3-, NO3-, PO43- e SO42- (cromatografia de íons). Os resultados foram submetidos à análise multivariada de dados. A análise de componentes principais das medianas de 12 variáveis (pH, condutividade, Li+, Na+, K+, Ca2+, Mg2+, Cl-, ClO3-, NO3-, PO43-, SO42-) dos 88 municípios indicou Ibitinga como local com água de características físico-químicas únicas, caracterizada pelas concentrações relativas mais altas de sulfato, cloreto, lítio e sódio, e aos valores maiores de pH e condutividade. Em adição, Ibitinga foi o único município que apresentou sistematicamente brometo na composição da água. Uma segunda análise de componentes principais envolvendo as amostras de Ibitinga indicou uma amostra com concentrações mais altas de cloreto e sulfato, e quatro amostras nas quais a presença de nitrato foi característica. Análises de agrupamento hierárquico exibiram a formação dos mesmos grupos produzidos nas duas análises de componentes. A validação dos métodos cromatográficos também é apresentada

    Avaliação da qualidade da fluoretação de águas de abastecimento público em 88 municípios da região Nordeste do estado de São Paulo (Brasil)

    Get PDF
    Introduction: During 1 year, the Núcleo de Ciências Químicas e Bromatológicas do Centro de Laboratório Regional do Instituto Adolfo Lutz de Ribeirão Preto (SP, Brasil) has increased the number of public water supply samples analyzed for fluoride concentration in relation to what is usually requested by 88 Municipal Sanitary Surveillance of Northeast State of São Paulo (Brazil). Objective: To verify if fluoridation indicators values will vary when increasing the number of samples analyzed and to assess the quality of fluoridation in the region. Method: Fluoride was determined by ion chromatography in samples collected by Sanitary Surveillances. Results: Indicators values of fluoridation obtained in the two sampling (Sanitary Surveillances and expanded) were similar for most cases. The mapping indicated a greater number of municipalities with values greater than 80% in Regional Departments of Health of Barretos and Franca, while in Araraquara and Ribeirão Preto prevail indicator values lower than 40%. Conclusions: Investment and technical assistance are insufficient to increase the values above 80% in municipalities with small populations. For the cases in which the values are smaller than 40% an approach based on the similarity between municipalities is suggested to increase these values.Introdução: Durante um ano, o Núcleo de Ciências Químicas e Bromatológicas do Centro de Laboratório Regional do Instituto Adolfo Lutz de Ribeirão Preto (SP, Brasil) aumentou o número de amostras de águas de abastecimento público analisadas para concentração de fluoreto em relação ao que é normalmente solicitado por 88 Vigilâncias Sanitárias Municipais do Nordeste do estado de São Paulo (Brasil). Objetivo: Verificar se os valores dos Indicadores de Fluoretação variam quando se aumenta o número de amostras analisadas e avaliar a qualidade da fluoretação na região. Método: Fluoreto foi determinado por cromatografia de íons em amostras coletadas pelas Vigilâncias Sanitárias. Resultados: Os valores dos Indicadores de Fluoretação obtidos nas duas amostragens (das Vigilâncias e as ampliadas) foram similares para a maioria dos casos. O mapeamento indicou um maior número de municípios com indicadores maiores que 80% nos Departamentos Regionais de Saúde de Barretos e Franca, enquanto nos de Araraquara e Ribeirão Preto prevalecem indicadores menores que 40%. Conclusões: Investimento e assessoria técnica são insuficientes para elevar os indicadores a valores acima de 80% em municípios com populações pequenas. Para os casos em que os valores são menores que 40% sugere-se uma abordagem baseada na similaridade entre municípios para se aumentar esses valores

    Magnetic properties of spin diluted iron pnictides from muSR and NMR in LaFe1-xRuxAsO

    Full text link
    The effect of isoelectronic substitutions on the microscopic properties of LaFe1-xRuxAsO, for 0< x< 0.8, has been investigated by means of muSR and 139La NMR. It was found that Ru substitution causes a progressive reduction of the N\`eel temperature (T_N) and of the magnetic order parameter without leading to the onset of superconductivity. The temperature dependence of 139La nuclear spin-lattice relaxation rate 1/T_1 can be suitably described within a two-band model. One band giving rise to the spin density wave ground-state, while the other one is characterized by weakly correlated electrons. Fe for Ru substitution yields to a progressive decrease of the density of states at the Fermi level close to the one derived from band structure calculations. The reduction of T_N with doping follows the predictions of the J_1-J_2 model on a square lattice, which appears to be an effective framework to describe the magnetic properties of the spin density wave ground-state.Comment: 6 pages, 8 figure

    Ocorrência de bromato em águas destinadas ao consumo humano

    Get PDF
    Introduction: Bromate is mutagenic and a probable carcinogen in humans. It usually does not occur in water for human consumption, but contamination can occur by industrial wastewater and in the disinfection process by ozonization (if bromide is present) or by the use of hypochlorite solution of unsatisfactory quality. Objective: Describe bromateconcentrations in the water supply of 89 municipalities in the state of São Paulo (Brazil), the physicochemical profiles of the waters in which the contaminant occurs, and a joint action between the Public Health Laboratory, the Sanitary Surveillance Regional Group and two Sanitary Surveillance of municipalities where important levels of bromate were found. Method: 4,853 samples were analyzed in 21 physicochemical parameters (including bromate concentration) and 2 microbiological parameters. For multivariate analysis, 4 demographic parameters were included. Results: Bromato was found in 224 samples (4.6% of the total) from 17 municipalities. The concentrations ranged between 3 and 199 μg L-1 and 56 samples (1.1% of the total) presented levels above the Maximum Allowed Value. Principal  Component Analysis in these 17 municipalities indicated KBrO3 as the predominant form of contamination. The contamination rates of two municipalities decreased from the availability to the Sanitary Surveillance of reports that included bromate results. Conclusions: The data suggest that the monitoring of bromate concentrations should be included in the routine of the Water Surveillance Program for Human Consumption in the state of São Paulo. The notifications of the Sanitary Surveillance with those responsible for the water supply of two municipalities were important to improve the quality of the water supplied to the population in relation to contamination.Introdução: Bromato é mutagênico e um provável carcinogênico em seres humanos. Normalmente não ocorre em águas para consumo humano, mas a contaminação pode ocorrer por águas residuárias industriais e pela desinfecção por ozonização (se brometo estiver presente) ou pelo uso de solução de hipoclorito de qualidade insatisfatória. Objetivo:Descrever as concentrações de bromato nas águas de abastecimento de 89 municípios do estado de São Paulo (Brasil), os perfis físico-químicos das águas nas quais o contaminante ocorre e uma ação conjunta entre Laboratório de Saúde Pública, Grupo de Vigilância Sanitária e de duas Vigilâncias Sanitárias dos municípios onde foram encontrados níveisimportantes de bromato. Método: Foram analisadas 4.853 amostras em 21 parâmetros físico-químicos (incluindo concentração de bromato) e dois microbiológicos. Para análise multivariada foram incluídos quatro parâmetros demográficos. Resultados: O bromato foi encontrado em 224 amostras (4,6% do total) de 17 municípios. As concentrações variaram entre 3 e 199 μg L-1 e 56 amostras (1,1% do total) apresentaram teores acima do valor máximo permitido. A Análise de Componentes Principais nesses 17 municípios indicou KBrO3 como a forma predominante de contaminação. Os índices de contaminação de dois municípios diminuíram a partir da disponibilização para as Vigilâncias Sanitárias de laudos que incluíram os resultados de bromato. Conclusões: Os dados sugerem que o monitoramento das concentrações de bromato deveria ser incluído na rotina do Programa de Vigilância da Água para Consumo Humano do estado de São Paulo. As notificações das Vigilâncias Sanitárias junto aos responsáveis pelo abastecimento de água de dois municípios foram importantes para a melhoria da qualidade da água fornecida à população em relação à contaminação

    Synthesis and physical properties of Ca1-xRExFeAs2 with RE = La ~ Gd

    Full text link
    Synthesis of a series of layered iron arsenides Ca1-xRExFeAs2 (112) was attempted by heating at 1000 C under a high-pressure of 2 GPa. The 112 phase successfully forms with RE = La, Ce, Nd, Sm, Eu and Gd, while Tb, Dy and Ho substituted and RE free samples does not contain the 112 phase. The Ce, Nd, Sm, Eu and Gd doped Ca1-xRExFeAs2 are new compounds. All of them exhibit superconducting transition except for the Ce doped sample. The behaviour of the critical temperature, with the RE ionic radii have been investigated

    Mapeamento da qualidade da água de abastecimento público no nordeste do estado de São Paulo (Brasil)

    Get PDF
    This paper presents data obtained on microbiological and physico-chemical analysis of 4347 public water supply samples from 88 municipalities in the Northeast region of the state of São Paulo, carried out within a year. In microbiological analysis, 288 samples showed positive results for indicator microorganisms, occurring an increase of 80% in the rainy season compared with the dry period. Physico-chemical analysis: in 1514 samples, lithium concentration was equal to or higher than the detection limit of the method; the nitrate concentration was greater than the maximum value allowed in 17 samples; 1730 samples showed fluoride content out-of-range of drinking pattern; bromate concentration was greater than the maximum value allowed in 16 samples; the pH value was outside the range recommended in 161 samples; 292 samples showed levels of free residual chlorine (FRC) outside the recommended range; 17 samples showed apparent color values above the maximum allowed; 13 samples showed turbidity values above the maximum allowed. By means of principal components analysis, it was possible to discriminate the waters of the region, with the formation of groups of municipalities with similar physico-chemical profiles, generating a mapping based on prominent variables.Esse trabalho apresenta dados obtidos em análises microbiológicas e físico-químicas de 4.347 amostras de águas de abastecimento público de 88 municípios da região nordeste do Estado de São Paulo, realizadas no período de um ano. Nos ensaios microbiológicos, 288 amostras apresentaram resultado positivo para microrganismos indicadores, ocorrendo um acréscimo de 80% no período de chuvas em comparação com o período de seca. Nos ensaios físico-químicos: em 1.514 amostras, a concentração de lítio foi igual ou superior ao limite de detecção do método; a concentração de nitrato foi superior ao valor máximo permitido em 17 amostras; 1.730 amostras apresentaram teor de fluoreto fora da faixa do padrão de potabilidade; a concentração de bromato foi superior ao valor máximo permitido em 16 amostras; o valor de pH situou-se fora do intervalo recomendado em 161 amostras; 292 amostras apresentaram teores de cloro residual livre fora da faixa recomendada; 17 amostras apresentaram valores de cor aparente acima do máximo permitido; 13 amostras apresentaram valores de turbidez acima do máximo permitido. Através da análise de componentes principais foi possível discriminar as águas de abastecimento da região, com a formação de grupos de municípios com águas de perfis físico-químicos similares, gerando um mapeamento baseado em variáveis proeminentes
    corecore