37 resultados para long lived
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Radiogenic He-4 is produced by the decay of uranium and thorium in the Earths mantle and crust. From here, it is degassed to the atmosphere(1-5) and eventually escapes to space(1,5,6). Assuming that all of the He-4 produced is degassed, about 70% of the total He-4 degassed from Earth comes from the continental crust(2,-5,7). However, the outgoing flux of crustal He-4 has not been directly measured at the Earths surface(2) and the migration pathways are poorly understood(2-4,7,8). Here we present measurements of helium isotopes and the long-lived cosmogenic radio-isotope Kr-81 in the deep, continental-scale Guarani aquifer in Brazil and show that crustal He-4 reaches the atmosphere primarily by the surficial discharge of deep groundwater. We estimate that He-4 in Guarani groundwater discharge accounts for about 20% of the assumed global flux from continental crust, and that other large aquifers may account for about 33%. Old groundwater ages suggest that He-4 in the Guarani aquifer accumulates over half- to one-million-year timescales. We conclude that He-4 degassing from the continents is regulated by groundwater discharge, rather than episodic tectonic events, and suggest that the assumed steady state between crustal production and degassing of He-4, and its resulting atmospheric residence time, should be re-examined.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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We review evidence that Stem Cell Factor (SCF) plays an important role in the pathophysiology of asthma. SCF is produced by a wide variety of cells present in asthmatic lung, including mast cells and eosinophils. Its receptor, c-kit, is broadly expressed on mature mast cells and eosinophils. SCF promotes recruitment of mast cell progenitors into tissues, as well as their local maturation and activation. It also promotes eosinophil survival, maturation and functional activation. SCF enhances IgE-dependent release of mediators from mast cells, including histamine, leukotrienes, cytokines (TNF-alpha, IL-5, GM-CSF) and chemokines (RANTES/CCL5, MCP-1/CCL2, TARC/CCL17 e MDC/CCL22); it is required for IL-4 production in mast cells. SCF, acting in concert with IgE, also upregulates the expression and function of CC chemokine receptors in mast cells. Structural and resident airway cells express increased levels of SCF in the bronchus of asthmatic patients. In a murine model of asthma, allergen exposure increased production of SCF by epithelial cells and alveolar macrophages, which was transient and paralleled by histamine release. SCF induced long-lived airway hyperreactivity, which was prevented by local neutralization of SCF, as well as by inhibitors of the production or activity of cysteinyl-leukotrienes. Together, these observations suggest that SCF has an important role in asthma.
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Data relative on the side occupied by females in double beds were collected in order to evaluate the feasebility to carryout a more extensive study to determine if this behavioral pattern is lateralized. Information relative to the side occupied in the bed, manual lateralization, how long lived togheter, and other related questions were collected in a sample of 229 women aged from 20 to 65 years old. Total frequencies of the bed side occupied showed to be equivalent, however, the left side showed to be chosen significantly more (70%)(χ2 = 5.4; 1 d.f.; p<0.05) when the choice was stated to be spontaneous (i.e, not determined by an impositive factor) . It is concluded that the obtained data give favourable support to an extensive study on the subject, which inserts into the area of research devoted to the understanding of the functional characteristics of central nervous functioning.
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PROBLEM: What is the experience from long-term psychiatric hospitalization? How can psychiatric nursing contribute to reduce the emotional suffering and the feeling of social exclusion related to this process?METHODS: This study was conducted on four women committed to long periods of psychiatric hospitalization in Brazil. Data were collected through open interviews and drawings made by the patients, and interpreted according to the theory of social representations.FINDINGS: Reports on the patients refer to a process of social exclusion, emotional suffering, and inadequate treatment in the hospital, leading to no other option but recurrent hospitalization.CONCLUSION: Negative experiences related to long-term hospitalization could possibly be minimized through adequate assistance provided by psychiatric nursing in open services, as proposed in the recent Brazilian psychiatric reform.