9,339 research outputs found

    Clinical study on the melarsoprol-related encephalopathic syndrome: risk factors and HLA association

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    Melarsoprol administration for the treatment of late-stage human African trypanosomiasis (HAT) is associated with the development of an unpredictable and badly characterized encephalopathic syndrome (ES), probably of immune origin, that kills approximately 50% of those affected. We investigated the characteristics and clinical risk factors for ES, as well as the association between the Human Leukocyte Antigen (HLA) complex and the risk for ES in a case-control study. Late-stage Gambiense HAT patients treated with melarsoprol and developing ES (69 cases) were compared to patients not suffering from the syndrome (207 controls). Patients were enrolled in six HAT treatment centres in Angola and in the Democratic Republic of Congo. Standardized clinical data was obtained from all participants before melarsoprol was initiated. Class I (HLA-A, HLA-B, HLA-Cw) and II (HLA-DR) alleles were determined by PCR-SSOP methods in 62 ES cases and 189 controls. The principal ES pattern consisted in convulsions followed by a coma, whereas ES with exclusively mental changes was not observed. Oedema, bone pain, apathy, and a depressed humour were associated with a higher risk of ES, while abdominal pain, coma, respiratory distress, and a Babinski sign were associated with higher ES-associated mortality. Haplotype C*14/B*15 was associated with an elevated risk for ES (OR: 6.64; p-value: 0.008). Haplotypes A*23/C*14, A*23/B*15 and DR*07/B*58 also showed a weaker association with ES. This result supports the hypothesis that a genetically determined peculiar type of immune response confers susceptibility for ES

    Synthesis and photophysical characterization of novel triphenylamine-benzimidazole derivatives

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    Research on organic luminescent materials has been intensely pursued due to their importance in technological applications related to signaling, fluorescent biosensory/chemosensory materials, molecular switches and organic light emitting diodes (OLEDs). Organic fluorophores such as triphenylamine and benzimidazole derivatives have attracted a particular attention owing to their high emission efficiency being widely used as electron transporters and emitting layers for OLEDs.1 Recently, we have been investigating the potential of heterocyclic systems bearing functionalized (benz)imidazole derivatives exhibiting high thermal stability, interesting emissive and chemosensory properties.2 In this communication we report the synthesis and photophysical characterization of triphenylamine-benzimidazoles (compounds 1a-d) which were synthesized by a one step reaction through the Na2S2O4 reduction of several commercially available o-nitroanilines in the presence of triphenylamine aldehyde in DMSO at 120 ¬įC. Compounds 1a-d bear different functionalization at position 5 of the benzimidazole with electron-donor or acceptor groups (Figure 1). A comprehensive spectral and photophysical investigation of these compounds including absorption, fluorescence and triplet-triplet absorption spectra, together with quantum yields of fluorescence, internal conversion, intersystem crossing and singlet oxygen and rate constants for the radiative and radiationless processes has been undertaken in solution at room temperature. It is shown that compounds 1a-d exhibit high fluorescence quantum yields (0.70-0.78). Additionally, a comparison between the optical and photophysical properties of 1a-d will be also presented and discussed.Funda√ß√£o para a Ci√™ncia e a Tecnologia (FCT

    Análise da produção brasileira de frutas a partir do armazém de dados da fruticultura.

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    Armazém de dados da fruticultura. Integração dos dados de produção de frutas. Análise da produção brasileira de frutas.bitstream/CNPTIA/9872/1/comuntec18_0.pd

    Análise de comércio exterior de frutas a partir do armazém de dados da fruticultura brasileira.

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    O objetivo geral do Programa √© elevar os padr√Ķes de qualidade e competitividade da fruticultura brasileira ao patamar de excel√™ncia requerido pelo mercado internacional, paradigma que ser√° efetivado com o avan√ßo da capacidade produtiva e gerencial dos produtores de frutas e a amplia√ß√£o dos mercados interno e externo. S√£o contempladas a√ß√Ķes em diversas √°reas, como inova√ß√£o tecnol√≥gica, capacita√ß√£o de fruticultores, controle de pragas na fruticultura, campanha para promo√ß√£o das frutas brasileiras, entre outras.bitstream/CNPTIA/9175/1/COMNICADOTEC2.pd
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