Generation, mobilization and crystallization of impact-induced alkali-rich melts in granitic target rocks: Evidence from the Araguainha impact structure, central Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This paper provides important insights into the generation, extraction and crystallization of clast-laden impact melt rocks from the Araguainha impact structure, central Brazil. Despite the mixed nature of the Araguainha target rocks (comprising a 2 km thick sequence of sedimentary rocks and underlying granitic basement), the exposed melt bodies are characterised by an alkali-rich granitic matrix embedding mineral and rock fragments derived only from the target granite. The melt rocks occur in the form of a massive impact melt sheet overlying the eroded central uplift structure, and as melt veins in the granite of the core of the central uplift. Bulk-rock major and trace element data (including platinum group elements) indicate that the precursor melts were generated locally, principally by partial melting of the target granite, without any contribution from the sedimentary sequence or the projectile. The dense network of melt veins was formed in isolation, by selective melting of plagioclase and alkali feldspar within the granite target. Plagioclase and alkali feldspar melted discretely and congruently, producing domains in the matrix of the melt veins, which closely match the stoichiometry of these minerals. The compositionally discrete initial melt phases migrated through a dense network of microfractures before being assembled into larger melt veins. Freezing of the melt veins was substantially fast, and the melt components were quenched in the form of alkali-feldspar and plagioclase schlieren in the matrix of the melt veins. The overlying impact melt rock is, in contrast, characterised by a granophyric matrix consisting of albite, sanidine, quartz, biotite and chlorite. In this case, melt components appear to have been more mobile and to have mixed completely to form a granitic parental melt. We relate the melting of the minerals to post-shock temperatures that exceeded the melting point of feldspars. (C) 2009 Elsevier Ltd. All rights reserved.732371837201Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)NRFConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Helmholtz Alliance "Planetary Evolution and Early Life"German Science Foundation (DFG) [RE 528/5-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [05/51530-3]German Science Foundation (DFG) [RE 528/5-1

Synthesis and thermal characterization of luminescent powers of terbium(III) with mixed ligands

This work deals with the synthesis and thermal decomposition of complexes of general formula: Ln(beta-dik)(3)L (where Ln=Tb(+3), beta-dik=4,4,4-trifluoro-1-phenyl-1,3butanedione(btfa) and L=1,10-fenantroline(phen) or 2,2-bipiridine(bipy). The powders were characterized by melting point, FTIR spectroscopy, LTV-visible, elemental analysis, scanning differential calorimeter(DSC) and thermogravimetry(TG). The TG/DSC curves were obtained simultaneously in a system DSC-TGA, under nitrogen atmosphere. The experimental conditions were: 0.83 ml.s(-1) carrier gas flow, 2.0 +/- 0.5 mg samples and 10 degrees C.min(-1) heating rate. The CHN elemental analysis of the Tb(btfa)(3)bipy and Tb(btfa)(3)phen complexes, are in good agreement with the expected values. The IR spectra evinced that the metal ion is coordinated to the ligands via C=O and C-N groups. The TG/DTG/DSC curves of the complexes show that they decompose before melting. The profiles of the thermal decomposition of the Tb(btfa)3phen and Tb(btfa)3bipy showed six and five decomposition stages, respectively. Our data suggests that the thermal stability of the complexes under investigation followed the order: Tb(btfa)(3)phen < Tb(btfa)(3)bipy

Comportamento e conhecimento: fundamentos para prevenção do pé diabético Comportamiento y conocimiento: fundamentos para la prevención del pié diabético Behavior and knowlege: basis for prevention of diabetic foot

OBJETIVO: Identificar o conhecimento e comportamento de pessoas diabéticas em relação aos cuidados com os pés. MÉTODOS: Estudo descritivo e transversal realizado em um centro de pesquisa e extensão universitária do interior paulista, em 2005. Foram entrevistados 55 pacientes diabéticos. Para a obtenção dos dados utilizamos um formulário, dois questionários e exame físico dos pés. RESULTADOS: As pessoas diabéticas não reconhecem a dimensão do risco real com relação aos pés. O conhecimento referido nem sempre se traduz na adoção de ações de autocuidado para a prevenção de problemas relacionados aos pés. Esta realidade aponta para a necessidade de considerarmos as particularidades de cada sujeito e sua interação com o ambiente, para delineamento das intervenções educativas. CONCLUSÕES: É preciso que os profissionais de saúde compreendam que o descompasso entre conhecimento e comportamento dos diabéticos não deve ser interpretado como um obstáculo intransponível, mas como um dos desafios fundamentais que precisam ser enfrentados.<br>OBJETIVO: Identificar el conocimiento y comportamiento de personas diabéticas en relación a los cuidados de los piés. MÉTODOS: Estudio descriptivo y transversal realizado en un centro de investigación y extensión universitaria del interior paulista, en el 2005. Fueron entrevistados 55 pacientes diabéticos. Para la obtención de los datos utilizamos un formulario, dos cuestionarios y examen físico de los piés. RESULTADOS: Las personas diabéticas no reconocen la dimensión del riesgo real en relación a los piés. El conocimiento referido no siempre se traduce en la adopción de acciones de autocuidado para la prevención de problemas relacionados a los piés. Esta realidad apunta hacia la necesidad de considerar las particularidades de cada sujeto y su interacción con el ambiente, para el delineamento de las intervenciones educativas. CONCLUSIONES: Es preciso que los profesionales de salud comprendan que el descompás entre conocimiento y comportamiento de los diabéticos no debe ser interpretado como un obstáculo intransferible, sino como uno de los desafíos fundamentales que precisan ser enfrentados.<br>OBJECTIVE: To describe the knowledge and behaviors of patients with diabetes towards foot care. METHODS: A cross-sectional descriptive study was conducted at a university research and intervention center in the interior of the state of São Paulo. Data were collected through interviews, two specific questionnaires, and physical examination of the foot in 55 patients in 2005. RESULTS: The participants did not recognize the dimension of the true risks regarding lack of foot care. The participant knowledge of diabetes did not translate into actions to prevent foot problems. These results suggest the need to take into consideration specific individual characteristics and the individual's interactions with the environment in designing educational interventions. CONCLUSIONS: Health care professionals need to understand that discrepancy between knowledge and behaviors of patients with diabetes is not an obstacle impossible to cross, but a challenging issue that needs to be addressed

Inequalities in access and utilization of dental services: a cross-sectional study in an area covered by the Family Health Strategy

This cross-sectional study aimed to investigate the presence of inequalities in the access and use of dental services for people living in the coverage area of the Family Health Strategy (FHS) in Ponta Grossa, Paraná State, Brazil, and to assess individual determinants related to them. The sample consisted of 747 individuals who answered a pre-tested questionnaire. Data analysis was performed by chi-square test and Poisson regression analysis, obtaining explanatory models for recent use and, by limiting the analysis to those who sought dental care, for effective access. Results showed that 41% of the sample had recent dental visits. The lowest visit rates were observed among preschoolers and elderly people. The subjects who most identified the FHS as a regular source of dental care were children. Besides age, better socioeconomic conditions and the presence of a regular source of dental care were positively associated to recent dental visits. We identified inequalities in use and access to dental care, reinforcing the need to promote incentives to improve access for underserved populations