1,657 research outputs found

    Sistema de alerta com base em estudo teórico-experimental de dispersão de poluentes solúveis em rios

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    Information about capacity of transport and dispersion of soluble pollutants in natural streams are important in the management of water resources, especially in planning preventive measures to minimize the problems caused by accidental or intentional waste, in public health and economic activities that depend on the use of water. Considering this importance, this study aimed to develop a warning system for rivers, based on experimental techniques using tracers and analytical equations of one-dimensional transport of soluble pollutants conservative, to subsidizing the decision-making in the management of water resources. The system was development in JAVA programming language and MySQL database can predict the travel time of pollutants clouds from a point of eviction and graphically displays the temporal distribution of concentrations of passage clouds, in a particular location, downstream from the point of its launch.Informações sobre a capacidade de transporte e dispersão de poluentes solúveis em cursos de água naturais são importantes no gerenciamento dos recursos hídricos, principalmente no planejamento preventivo de medidas que visem a minimizar problemas à saúde pública e às atividades econômicas que dependem do uso da água, ocasionados por despejos acidentais ou intencionais. Considerando tal importância, este trabalho teve como objetivo desenvolver um sistema de alerta para rios, com base em resultados experimentais, utilizando técnicas de traçadores e equações analíticas de transporte unidimensional de poluentes solúveis conservativos, visando a subsidiar a tomada de decisão no gerenciamento dos recursos hídricos. O sistema desenvolvido em linguagem de programação JAVA e banco de dados MySQL permite prever o tempo de percurso da nuvem de poluentes a partir de um ponto de despejo de um poluente e apresenta, graficamente, a distribuição temporal de concentrações da passagem da nuvem, em um determinado local, à jusante do ponto do seu lançamento

    Evaluation of gene amplification and protein expression of HER-2/neu in esophageal squamous cell carcinoma using Fluorescence in situ Hybridization (FISH) and immunohistochemistry

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    <p>Abstract</p> <p>Background</p> <p>Esophageal squamous cell carcinoma (ESCC) is the sixth most frequent neoplasia in Brazil. It is usually associated with a poor prognosis because it is often at an advanced stage when diagnosed and there is a high frequency of lymph node metastases. It is important to know what prognostic factors can facilitate diagnosis, optimize therapeutic decisions, and improve the survival of these patients. A member of the epidermal growth factor receptor (EGFR) family, c-erbB-2, has received much attention because of its therapeutic implications; however, few studies involving fluorescence <it>in situ </it>hybridization (FISH) analysis of HER-2/neu gene amplification and protein expression in ESCC have been conducted. The aim of this study was to verify the presence of HER-2/neu gene amplification using FISH, and to correlate the results with immunohistochemical expression and clinical-pathological findings.</p> <p>Methods</p> <p>One hundred and ninety-nine ESCC cases were evaluated using the Tissue Microarray (TMA) technique. A polyclonal antibody against c-erbB-2 was used for immunohistochemistry. Analyses were based on the membrane staining pattern. The results were classified according to the Herceptest criteria (DAKO): negative (0/1+), potential positive (2+) and positive (3+). The FISH reactions were performed according to the FISH HER2 PharmDx (DAKO) protocol. In each case, 100 tumor nuclei were evaluated. Cases showing a gene/CEN17 fluorescence ratio ≥ 2 were considered positive for gene amplification.</p> <p>Results</p> <p>The c-erbB-2 expression was negative in 117/185 cases (63.2%) and positive in 68 (36.8%), of which 56 (30.3%) were 2+ and 12 (6.5%) were 3+. No significant associations were found among protein expression, clinicopathological data and overall survival. Among the 47 cases analyzed, 38 (80.9%) showed no gene amplification while 9 (19.1%) showed amplification, as demonstrated by FISH. Cases that were negative (0/1+) and potential positive (2+) for c-erbB-2 expression by immunohistochemistry showed no gene amplification. However, all cases with gene amplification were positive (3+) by immunohistochemistry. According to univariate analysis, there was a significant difference (p = 0.003) in survival rates when cases with and without HER-2/neu amplification were compared.</p> <p>Conclusion</p> <p>Our data demonstrate the correspondence between gene amplification and protein expression of HER-2/neu. Gene amplification is an indicator of poor prognosis in ESCC.</p

    Conserved and highly expressed tRNA derived fragments in zebrafish

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    Background: Small non-coding RNAs (sncRNAs) are a class of transcripts implicated in several eukaryotic regulatory mechanisms, namely gene silencing and chromatin regulation. Despite significant progress in their identification by next generation sequencing (NGS) we are still far from understanding their full diversity and functional repertoire. Results: Here we report the identification of tRNA derived fragments (tRFs) by NGS of the sncRNA fraction of zebrafish. The tRFs identified are 18–30 nt long, are derived from specific 5′ and 3′ processing of mature tRNAs and are differentially expressed during development and in differentiated tissues, suggesting that they are likely produced by specific processing rather than random degradation of tRNAs. We further show that a highly expressed tRF (5′tRF-ProCGG) is cleaved in vitro by Dicer and has silencing ability, indicating that it can enter the RNAi pathway. A computational analysis of zebrafish tRFs shows that they are conserved among vertebrates and mining of publicly available datasets reveals that some 5′tRFs are differentially expressed in disease conditions, namely during infection and colorectal cancer. Conclusions: tRFs constitute a class of conserved regulatory RNAs in vertebrates and may be involved in mechanisms of genome regulation and in some diseases. Keywords: tRNA derived fragments, Zebrafish, Small non coding RNAs, tRNAspublishe

    Mitochondrial echoes of first settlement and genetic continuity in El Salvador

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    Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

    Characterization of leaves and barks of Rhamnidium elaeocarpum Reissek

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    As folhas e cascas da Rhamnidium elaeocarpum Reissek (Rhamnaceae), conhecida como cafezinho, são utilizadas popularmente no Brasil para reduzir o prurido das gengivas de crianças no início da dentição e para dores estomacais. O objetivo desse trabalho foi realizar a caracterização das folhas, cascas do caule e cascas da raiz da R. elaeocarpum. Observou-se que as folhas são opostas cruzadas simples, hipoestomáticas, apresentando tricomas tectores sobre as nervuras. As cascas das raízes possuem cicatrizes ou fendas na face externa e fratura fibrosa na face interna. Verificou-se a presença de flavonóides, alcalóides, saponinas e taninos em todas as amostras. Esses resultados podem subsidiar estudos futuros, pois contribuiram para a obtenção de dados padrão visando o controle de qualidade da matéria-prima dessa espécie.The leaves and barks of Rhamnidium elaeocarpum Reissek (Rhamnaceae), known as cafezinho, are popularly used in Brazil to reduce gums itching of the children at the teeth beginning and the stomach pain. The work was a characterization the leaves, stem bark and root bark of R. elaeocarpum. It was observed that the leaves are cross-opposite simple, hypostomatic, showing trichomes on the veins. The roots bark have scars or cracks on the outside and fibrous fracture on the inner side. It was detected the presence of flavonoids, alkaloids, saponins and tannins in all samples. These results may support future studies, allowing to obtain data to the standard quality control of raw material of this species.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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