989 resultados para Tsallis distribution. Solar Neutrino. TGEC


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Introduction Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed. Methods Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique. Results A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identified: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B. Conclusions In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.

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Introduction Vector seasonality knowledge is important for monitoring and controlling of vector-borne diseases. Lutzomyia longipalpis (Lu. longipalpis) is the main vector of Leishmania (Leishmania) infantum Nicolle, 1908, which is the causative agent of visceral leishmaniasis in the Americas. Methods Lu. longipalpis was monitored for 3 consecutive nights each month using light traps from the Centers for Disease Control in the peridomiciles and intradomiciles of 18 residences from January 2005 to December 2012 in the urban area of Dracena, a medium-sized city located in the western region of São Paulo, Brazil. Results A total of 54,820 Lu. longipalpis specimens were collected, and the proportion of positive samples was significantly higher in the peridomiciles than in the intradomiciles (p<0.05) in all 8 years of the study, except for 2005. The vector was present in all study years in the 9 sub-regions of the city, and the male/female ratio ranged from 3.19 to 4.26. The greatest vector abundance occurred in the first semester and peaked in March, confirming its seasonality. Conclusions The maintenance of this high abundance over an 8-year surveillance period demonstrates the vector adaptation to the urban conditions of the city. These characteristics present a major challenge for preventing human and canine contact with the vector and, consequently, controlling the spread of disease.

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Os polímeros são materiais de grande interesse científico e tecnológico já que podem ser utilizados no desenvolvimento de dispositivos para aplicação em electrónica e fotónica. Tendo em conta a sua aplicação em dispositivos de conversão de energia solar em energia eléctrica, o estudo das propriedades eléctricas e ópticas de filmes destes materiais, quando irradiados por radiação ultravioleta e visível, é fundamental. Neste trabalho caracterizaram-se as propriedades eléctricas e ópticas de filmes finos obtidos pelas técnicas de derramamento e de camada-por-camada (Layer-by-Layer (LbL)) obtidos a partir do poli(cloreto de xilideno tetrahidrotiofeno) (PTHT) que após aquecimento é convertido em poli(p-fenileno vinileno) (PPV). Assim, e através da técnica de derramamento, foram preparados filmes sobre suportes sólidos com eléctrodos interdigitais de forma a proceder à medição da condutividade em modo de corrente alternada (AC), isto é, à medição da resistência e da capacidade em função da frequência. Verificou-se, portanto, que a presença de luz leva à formação de portadores de carga, ou seja, na presença de luminosidade os filmes apresentam uma menor capacitância e resistência, para além de degradar o material. Esta degradação foi verificada, também, a partir da espectrofotometria de Ultravioleta-Visível (UV-Vis) e de infravermelho (IV). Medições de condutividade de volume, isto é, colocando os filmes entre eléctrodos paralelos de funções de trabalho diferentes, permitiram traçar as curvas características e verificar que os dispositivos obtidos se comportam como díodos. Recorreu-se, também, a técnicas de espectrofotometria de ultravioleta do vácuo (VUV) e UV-Vis para caracterizar filmes LbL obtidos a partir do PTHT e de um polieletrólito comum o poli(estireno sulfonado) (PSS) antes e após aquecimento. Os espectros obtidos, após análise dos picos, mostram que a técnica de VUV é a técnica indicada para analisar a conversão do PTHT em PPV. Este trabalho permitiu concluir que as propriedades eléctricas e ópticas destes filmes, estão dependentes da presença de luminosidade, de oxigénio e da humidade relativa pelo que dispositivos obtidos a partir deste polímero devem ser, sempre, encapsulados.

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Introduction: In past decades, leishmaniasis burden has been low across Egypt; however, changing environment and land use has placed several parts of the country at risk. As a consequence, leishmaniasis has become a particularly difficult health problem, both for local inhabitants and for multinational military personnel. Methods: To evaluate coarse-resolution aspects of the ecology of leishmaniasis transmission, collection records for sandflies and Leishmania species were obtained from diverse sources. To characterize environmental variation across the country, we used multitemporal Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2005-2011. Ecological niche models were generated using MaxEnt, and results were analyzed using background similarity tests to assess whether associations among vectors and parasites (i.e., niche similarity) can be detected across broad geographic regions. Results: We found niche similarity only between one vector species and its corresponding parasite species (i.e., Phlebotomus papatasi with Leishmania major), suggesting that geographic ranges of zoonotic cutaneous leishmaniasis and its potential vector may overlap, but under distinct environmental associations. Other associations (e.g., P. sergenti with L. major) were not supported. Mapping suitable areas for each species suggested that northeastern Egypt is particularly at risk because both parasites have potential to circulate. Conclusions: Ecological niche modeling approaches can be used as a first-pass assessment of vector-parasite interactions, offering useful insights into constraints on the geography of transmission patterns of leishmaniasis.

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Introduction: Paracoccidioidomycosis (PCM) is a systemic infection caused by the fungus Paracoccidioides brasiliensis. PCM is considered one of the most important systemic mycoses in Latin America. Methods: This is a clinical, epidemiological, retrospective, quantitative study of PCM cases in patients attending the National Health Service in the State of Rondônia in 1997-2012. The examined variables included sex, age group, year of diagnosis, education level, profession, place of residence, diagnostic test, prior treatment, medication used, comorbidities and case progress. Results: During the study period, 2,163 PCM cases were registered in Rondônia, and the mean annual incidence was 9.4/100,000 people. The municipalities with the highest rates were located in the southeastern region of Rondônia, and the towns of Pimenteiras do Oeste and Espigão do Oeste had the highest rates in the state, which were 39.1/100,000 and 37.4/100,000 people, respectively. Among all cases, 90.2% and 9.8% were observed in men and women, respectively, and most cases (58.2%) were observed in patients aged between 40 and 59 years. Itraconazole was used to treat 91.6% (1,771) of cases, followed by sulfamethoxazole in combination with trimethoprim (4.4% [85] of cases). One hundred thirty-one (6%) patients died. Conclusions: The State of Rondônia has a high incidence of PCM, and the municipalities in the southeastern region of the state were found to have the highest incidence rates of this disease. Our findings suggest that Rondônia is the state in the northern region with the highest mortality rate for PCM.

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Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração.

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Introduction This work presents the initial findings of a molecular epidemiological investigation of Trypanosoma cruzi in triatomine insects in State of Mato Grosso do Sul. Methods A total of 511 triatomines from different regions of the state were examined. Deoxyribonucleic acid (DNA) was extracted from the intestinal contents of the insects using phenol-chloroform-isoamyl alcohol (25:24:1). Polymerase chain reaction (PCR) using primers 121/122 targeting DNA kinetoplast (kDNA) was then performed to identify T. cruzi, and positive samples were subjected to PCR using the primer pair TcSC5D-F/R followed by restriction fragment length polymorphism (RFLP) with the restriction enzymes SphI and HpaI (1 U/reaction), cloning and sequencing. Results One hundred samples were positive for T. cruzi, and three discrete typing units (DTUs) were identified (TcI, TcII, and TcBat). Triatoma sordida had the highest T. cruzi occurrence (83.3%), and DTUs were found in three samples: 58.3% of the samples were TcI, 33.3% were TcII and 8.3% were TcBat. There was a clear geographical distribution of the DTUs throughout the state, with TcI, TcII and TcBat located in the center, TcI located in the east, and TcII located in the west. Conclusions This study showed the occurrence of overlapping DTUs in State of Mato Grosso do Sul. The distributions of the DTUs were different, with TcI, TcII and TcBat in the center of the state, TcI predominantly in the east, and TcII in the west. Further studies may reveal a more defined mosaic distribution of DTUs in MS.

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Introduction More than half of the malaria cases reported in the Americas are from the Brazilian Amazon region. While malaria is considered endemic in this region, its geographical distribution is extremely heterogeneous. Therefore, it is important to investigate the distribution of malaria and to determine regions whereby action might be necessary. Methods Changes in malaria indicators in all municipalities of the Brazilian Amazon between 2003-2004 and 2008-2009 were studied. The malaria indicators included the absolute number of malaria cases and deaths, the bi-annual parasite incidence (BPI), BPI ratios and differences, a Lorenz curve and Gini coefficients. Results During the study period, mortality from malaria remained low (0.02% deaths/case), the percent of municipalities that became malaria-free increased from 15.6% to 31.7%, and the Gini coefficient increased from 82% to 87%. In 2003, 10% of the municipalities with the highest BPI accumulated 67% of all malaria cases, compared with 2009, when 10% of the municipalities (with the highest BPI) had 80% of the malaria cases. Conclusions This study described an overall decrease in malaria transmission in the Brazilian Amazon region. As expected, an increased heterogeneity of malaria indicators was found, which reinforces the notion that a single strategy may not bring about uniformly good outcomes. The geographic clustering of municipalities identified as problem areas might help to define better intervention methods.

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Os polímeros são materiais de grande interesse científico e tecnológico já que podem ser utilizados no desenvolvimento de dispositivos para aplicação em electrónica e fotónica. Tendo em conta a sua aplicação em dispositivos de conversão de energia solar em energia eléctrica, o estudo das propriedades eléctricas e ópticas de filmes destes materiais, quando irradiados por radiação ultravioleta e visível, é fundamental. Neste trabalho caracterizaram-se as propriedades eléctricas e ópticas de filmes finos obtidos pelas técnicas de derramamento e de camada-por-camada (Layer-by-Layer (LbL)) obtidos a partir do poli(cloreto de xilideno tetrahidrotiofeno) (PTHT) que após aquecimento é convertido em poli(p-fenileno vinileno) (PPV). Assim, e através da técnica de derramamento, foram preparados filmes sobre suportes sólidos com eléctrodos interdigitais de forma a proceder à medição da condutividade em modo de corrente alternada (AC), isto é, à medição da resistência e da capacidade em função da frequência. Verificou-se, portanto, que a presença de luz leva à formação de portadores de carga, ou seja, na presença de luminosidade os filmes apresentam uma menor capacitância e resistência, para além de degradar o material. Esta degradação foi verificada, também, a partir da espectrofotometria de Ultravioleta-Visível (UV-Vis) e de infravermelho (IV). Medições de condutividade de volume, isto é, colocando os filmes entre eléctrodos paralelos de funções de trabalho diferentes, permitiram traçar as curvas características e verificar que os dispositivos obtidos se comportam como díodos. Recorreu-se, também, a técnicas de espectrofotometria de ultravioleta do vácuo (VUV) e UV-Vis para caracterizar filmes LbL obtidos a partir do PTHT e de um polieletrólito comum o poli(estireno sulfonado) (PSS) antes e após aquecimento. Os espectros obtidos, após análise dos picos, mostram que a técnica de VUV é a técnica indicada para analisar a conversão do PTHT em PPV. Este trabalho permitiu concluir que as propriedades eléctricas e ópticas destes filmes, estão dependentes da presença de luminosidade, de oxigénio e da humidade relativa pelo que dispositivos obtidos a partir deste polímero devem ser, sempre, encapsulados.

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Apesar do elevado potencial do metal magnésio como material útil em várias áreas cien-tíficas e tecnológicas, os seus métodos de produção tradicionais têm um impacto fortemente prejudicial no ambiente e um custo elevado. Este facto é um incentivo à procura de novas so-luções, nomeadamente as que recorrem à utilização da radiação solar partindo do óxido de magnésio. Alguns estudos têm já sido feitos nesse sentido, utilizando laser solar ou radiação solar concentrada mas a utilização concertada dos dois não tinha sido feita até ao momento. Neste trabalho, a exequibilidade da utilização concertada destes dois métodos será avaliada e será estudado o comportamento do óxido de magnésio face à radiação que nele incide.

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Este trabalho consistiu no estudo técnico-económico (dimensionamento) de uma central térmica solar de torre norte, com back-up a biomassa (pellets) para produção de energia elétrica. A partir da plataforma PVGIS obteve-se a irradiação normal direta, DNI, da região do Alentejo, Portugal, segundo critérios descritos na secção 3.1. O valor anual obtido foi de 2319 !"ℎ/%&, valor este que foi convertido em energia elétrica, obtendo-se, assim, um montante de 105.761.800 kWh por ano, em 25 anos. Estas importâncias foram obtidas através dos equipamentos que constituem a central, entre eles o campo solar (composto por 2067 helióstatos com área total de 188097 %&), a torre (convertendo a concentração da DNI para energia térmica ao fluído de transferência de calor, HTF), o bloco de potência (composta por permutador de calor, turbina, gerador elétrico e outros) e com ajuda de uma caldeira a biomassa (pellets) que consome cerca de 24.001,23 toneladas de pellets por ano. O estudo económico foi realizado num modelo executável no Excel, calculando, assim, o custo total do sistema, 138.515.886,87 €. A partir deste valor calcularam-se os indicadores económicos (Valor Atualizado Líquido, VAL=-12.282540,28 €) com uma tarifa bonificada de 0,22114 €/kWh, que indica que o sistema termo solar com back-up a biomassa (pellets) não é viável economicamente (e o mesmo acontece com o sistema termo solar sem a biomassa). O dimensionamento técnico do sistema CSP de torre é feito a partir de um modelo matemático executado em Excel e MatLab e pelo software System Advisor Model, SAM e o da caldeira a pellets é concretizado também no Excel. Os resultados do modelo matemático foram comparados com os valores obtidos no SAM para o mês típico de julho comprovando, assim, as fórmulas e conceitos contidos no estado da arte. Realizou-se, também, uma comparação dos valores anuais do sistema obtidos no SAM com os valores reais da Gemasolar (em Espanha), demonstrando então a veracidade dos valores obtidos no dimensionamento feito para Portugal.

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INTRODUCTION: Epidemiological data on the prevalence of extended-spectrum β-lactamases (ESBLs) are scarce in Brazil despite the fact that these data are essential for empirical treatment and control measures. The objective of this study was to evaluate the prevalence of different ESBLs by type and distribution in a tertiary hospital in southern Brazil. METHODS: We evaluated 1,827 enterobacterial isolates between August 2003 and March 2008 isolated from patients at a tertiary hospital. Samples were identified using a Vitek automated system and were confirmed by biochemical testing. The identified ESBL strains were characterized by phenotypic methods, polymerase chain reaction (PCR), and sequencing. Genetic similarities were evaluated by pulsed-field gel electrophoresis. RESULTS: It was 390 (21.3%) ESBL-producing strains, which expressed the ESBLs CTX-M (292), SHV (84), CTX and SHV (10), TEM (2), and PER (2). CONCLUSIONS: The prevalence of ESBL-expressing strains was high, especially in Klebsiella pneumoniae and Enterobacter spp. CTX-M was the predominant type of ESBL observed, and its genetic variability indicates a polyclonal distribution.

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Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

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INTRODUCTION: Visceral leishmaniasis (VL) is a zoonosis of great importance to public health and is considered a neglected disease by the World Health Organization. The disease has expanded and become more prevalent in urban areas in Brazil. METHODS: Geospatial analyses were performed and thematic maps of the triad of the disease were produced for the study period (2003-2012) in the urban area of the municipality of Rondonópolis in the midwestern State of Mato Grosso (MT), Brazil, TerraView 4.2.2 software was used for the analyses. RESULTS: A total of 87.9% of the 186 confirmed human cases of VL were cured. Children between the ages of 1 and 4 were the most affected. Registered deaths were predominant among adults aged 60 years or older. The urban area of the municipality consists of eight strata and 12 census districts include 237 neighborhoods. All sectors had confirmed cases of VL. During the study period, human cases of the disease were recorded in 90 neighborhoods. The 23 deaths from the disease were distributed in 21 neighborhoods. Sandflies carrying the parasite were captured in 192 out of 200 neighborhoods evaluated for the presence of the VL vector. The presence of dogs carrying the parasite was confirmed in, 140 out of 154 surveyed neighborhoods. CONCLUSIONS: The data demonstrated the endemic nature of VL, with a high percentage of infected children, a high distribution of canine infection, and a wide adaptation and dispersal of the vectors in the urban environment. These results, illustrate the process of urbanization of VL in the municipality of Rondonópolis, MT, Brazil.