142 research outputs found

    Cálculo da altitude dos pontos culminantes: Aconcágua, Elbrus, Everest e Kilimanjaro, a partir da Metodologia do IHRS

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    Trabalho de Conclusão de Curso (Graduação)A Associação Internacional de Geodésia, em 2015, publicou a Resolução N° 1 sobre a definição e realização de um Sistema de Referência Internacional para Altitudes especificando que coordenadas altimétricas de pontos ou objetos próximos ou na superfície da Terra serão fornecidas por números geopotenciais (C) referindo-se a uma mesma superfície equipotencial definida pelo valor convencional W_0 = 62.636.853,4 m^2 s^(-2). Atualmente, as altitudes dos pontos culminantes de cada continente, chamados 7 cumes, são referenciadas a diferentes sistemas de altitudes, sendo assim, não estão associadas a uma mesma superfície de referência. Logo, o objetivo desse trabalho foi a partir da metodologia do International Heigh Heference System, estimar as altitudes dos pontos culminantes dos Montes Aconcágua, Elbrus, Everest e Kilimanjaro. Para tanto, se utilizou valores de potencial derivados de modelos globais do geopotencial, com seu maior grau e ordem, e de modelos geoidais. Os resultados obtidos foram comparados aos valores fornecidos pelo órgão responsável pelo cálculo em seu território ou por órgãos de maior confiança quando não encontrado valores oficiais. A partir dos resultados foi verificou-se um melhor desempenho para a metodologia a partir de modelos geoidais. As altitudes do Everest e Aconcágua apresentaram uma diferença menor que 0,50 m, enquanto que o Elbrus e o Kilimanjaro acima de 4,00 m

    Impact of Diesel Exhaust Particles on Th2 Response in the Lung in Asthmatic Mice

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    Although it has been accepted that pulmonary exposure to diesel exhaust particles (DEP), representative constituents in particulate matter of mass median aerodynamic diameter < or 2.5 µm (PM2.5), exacerbates murine allergic asthma, the in vivo effects of DEP on their cellular events in the context of allergen-specific Th response have never been examined. The aim of this study is to elucidate whether in vivo repetitive exposure to DEP combined with allergen (ovalbumin) facilitate allergen-specific Th response in the lung using a simple ex vivo assay system. As a result, repetitive pulmonary exposure to DEP in vivo, if combined with allergen, amplifies ex vivo allergen-specific Th2 response in the lung compared to that to allergen alone, characterized by high levels of interleukin (IL)-4 and IL-5. The result suggests that in asthmatic subjects, DEP promote Th2-prone milieu in the lung, which additively/synergistically augment asthma pathophysiology in vivo

    Extensive Analysis of Elastase-Induced Pulmonary Emphysema in Rats: ALP in the Lung, a New Biomarker for Disease Progression?

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    It is accepted that pulmonary exposure of rodents to porcine pancreatic elastase (ELT) induces lesions that morphologically resemble human emphysema. Nonetheless, extensive analysis of this model has rarely been conducted. The present study was designed to extensively examine the effects of ELT on lung inflammation, cell damage, emphysematous change, and cholinergic reactivity in rats. Intratracheal administration of two doses of ELT induced 1) a proinflammatory response in the lung that was characterized by significant infiltration of macrophages and an increased level of interleukin-1β in lung homogenates, 2) lung cell damage as indicated by higher levels of total protein, lactate dehydrogenase, and alkaline phosphatase (ALP) in lung homogenates, 3) emphysema-related morphological changes including airspace enlargement and progressive destruction of alveolar wall structures, and 4) airway responsiveness to methacholine including an augmented Rn value. In addition, ELT at a high dose was more effective than that at a low dose. This is the novel study to extensively analyze ELT-induced lung emphysema, and the analysis might be applied to future investigations that evaluate new therapeutic agents or risk factors for pulmonary emphysema. In particular, ALP in lung homogenates might be a new biomarker for the disease progression/exacerbation

    Sequence-specific cleavage of RNA by a hybrid ribonuclease H

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    AbstractSite-specific cleavage of the 22-, 132- and 534-base RNAs by the DNA/protein hybrid R Nase H were examined. The 22-base RNA was chemically synthesized, and 132- and 534-base RNAs were prepared by run-off transcription. The hybrid enzyme cleaves these RNAs, which contain a single target sequence, primarily at the unique phosphodiester bond within the target sequence. The hybrid enzyme performs multiple turnovers, and at a substrate/enzyme ratio of 10:1 the RNAs are almost completely cleaved by the hybrid enzyme at 37°C within 1 h. We propose that hybrid RNase H molecules with various oligodeoxyribonucleotides function as RNA restriction enzymes and are useful for structural and functional studies of RNA

    An Arabidopsis SBP-domain fragment with a disrupted C-terminal zinc-binding site retains its tertiary structure

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    AbstractSQUAMOSA promoter-binding proteins (SBPs) form a major family of plant-specific transcription factors, mainly related to flower development. SBPs share a highly conserved DNA-binding domain of ∼80 amino acids (SBP domain), which contains two non-interleaved zinc-binding sites formed by eight conserved Cys or His residues. In the present study, an Arabidopsis SPL12 SBP-domain fragment that lacks a Cys residue involved in the C-terminal zinc-binding pocket was found to retain a folded structure, even though only a single Zn2+ ion binds to the fragment. Solution structure of this fragment determined by NMR is very similar to the previously determined structures of the full SBP domains of Arabidopsis SPL4 and SPL7. Considering the previous observations that chelating all the Zn2+ ions of SBPs resulted in the complete unfolding of the structure and that a mutation of the Cys residue equivalent to that described above impaired the DNA-binding activity, we propose that the Zn2+ ion at the N-terminal site is necessary to maintain the overall tertiary structure, while the Zn2+ ion at the C-terminal site is necessary for the DNA binding, mainly by guiding the basic C-terminal loop to correctly fit into the DNA groove

    Safety and Efficacy of FIT039 for Verruca Vulgaris: A Placebo-Controlled, Phase I/II Randomized Controlled Trial

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    TRIAL DESIGN: Human papillomavirus infection causes verruca vulgaris. CDK9 inhibitor FIT039 inhibits DNA virus proliferation in animal models. We conducted a multicenter, single-blind, placebo-controlled, randomized phase I/II clinical trial evaluating the safety and efficacy of FIT039 against verruca vulgaris. METHODS: Target lesions were treated with liquid nitrogen once, and a FIT039 patch or placebo patch was applied for 14 days. The primary endpoint was lesion disappearance. The secondary endpoints were safety and changes in dimension, cross-sectional area, and the number of petechial lesions. RESULTS: A total of 24 participants were randomly allocated to the FIT039 (n = 13, median age, 54 years) and placebo (n = 11, median age, 62 years) groups. Verruca vulgaris did not disappear. FIT039 decreased the dimension to 76% of the initial value on day 29, followed by an increase to 98% on day 57. Placebo showed a monotonic increase to 107% on day 57. Changes in the cross-sectional area and petechiae number were comparable between the groups. CONCLUSIONS: No drug-related adverse reactions occurred. FIT039 efficacy was not determined in this study
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