Microstructural and electrical properties of PbTIO3 screen-printed thick films

In this article we will study the structural and electrical properties of PbTiO3 (PTO) screen-printed thick films. These properties can change with synthetic routes employed for synthesis of PTO. The ceramic powder has been synthesized by mechanical alloying and solid state route. This material crystallizes in the tetragonal system, with space group P4mm and unit cell dimensions a = b = 3.904, c = 4.152 angstrom, and Z = 1. From our results, it was observed that PTO obtained by mechanical alloying provides smaller crystallite size. The Rietveld refinement showed that the samples synthesized by mechanical alloying and solid state route crystallize in the tetragonal system but with different cell parameters. The Raman shifts of these films agree with modes from literature. However, some displacements happen, because the morphology and structural characteristics of the thick films are different, compared to single crystal and thin film. The photomicrographs of the PTO thick films showed that the choice of synthetic routes obtained samples with different microstructures.191097398

Is dynamometry able to infer the risk of muscle mass loss in patients with COPD?

Dionei Ramos,1 Giovana Navarro Bertolini,1 Marceli Rocha Leite,1 Luiz Carlos Soares Carvalho Junior,1 Paula Roberta da Silva Pestana,1 Vanessa Ribeiro dos Santos,2 Ana Claudia de Souza Fortaleza,2 Fernanda Maria Machado Rodrigues,1 Ercy Mara Cipulo Ramos1 1Department of Physiotherapy, São Paulo State University, Presidente Prudente, Brazil; 2Department of Motricity Sciences, São Paulo State University, Rio Claro, Brazil Introduction: Sarcopenia is characterized by a progressive and generalized decrease of strength and muscle mass. Muscle mass loss is prevalent in patients with chronic obstructive pulmonary disease (COPD) as a result of both the disease and aging. Some methods have been proposed to assess body composition (and therefore identify muscle mass loss) in this population. Despite the high accuracy of some methods, they require sophisticated and costly equipment.Aim: The purpose of this study was to infer the occurrence of muscle mass loss measured by a sophisticated method (dual energy X-ray absorptiometry [DEXA]) using a more simple and affordable equipment (dynamometer).Methods: Fifty-seven stable subjects with COPD were evaluated for anthropometric characteristics, lung function, functional exercise capacity, body composition, and peripheral muscle strength. A binary logistic regression model verified whether knee-extension strength (measured by dynamometry) could infer muscle mass loss (from DEXA).Results: Patients with decreased knee-extension strength were 5.93 times more likely to have muscle mass loss, regardless of sex, disease stage, and functional exercise capacity (P=0.045).Conclusion: Knee-extension dynamometry was able to infer muscle mass loss in patients with COPD. Keywords: COPD, sarcopenia, peripheral muscle strength &nbsp

Microstructure and magneto-dielectric properties of ferrimagnetic composite GdIG(X):YIG(1-X) at radio and microwave frequencies

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The gadolinium iron garnet (GdIG, Gd3Fe5O12) and yttrium iron garnet (YIG, Y3Fe5O12), and their GdIG(X):YIG(1-X) composites, were obtained by a new solid-state procedure. The microstructure of the samples was studied by X-ray powder diffraction and Rietveld refinement, Vickers microhardness and scanning electron microscopy. The density and microhardness behavior were studied as a function of the lattice parameters for the composite samples. In the present work, the magnetic and dielectric properties of the GdlG(X):YIG(1-X) composite at radio and microwave frequencies were also studied. The magnetic permeability and dielectric permittivity and loss properties for the composite GdIG(X):YIG(1-X) showed good potential for use in components, when one is looking for moderate epsilon(r)' and mu(r)' materials with low loss in the radio-frequency and microwave range. (C) 2009 Elsevier Ltd. All rights reserved.705804810Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FUNCAP (Brazilian agencies)CELESTICAUS Air Force Office of Scientific Research (AFOSR) [FA9550-08-1-0210]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)US Air Force Office of Scientific Research (AFOSR) [FA9550-08-1-0210

Associative diazotrophic bacteria in grass roots and soils from heavy metal contaminated sites

This work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (Zinc, Cadmium and NaCl tolerance in vitro, and protein profiles) and genotypically (16S rDNA sequencing), as compared to type strains of known diazotrophic species. Densities were evaluated by using NFb, Fam and JNFb media, commonly used for enrichment cultures of diazotrophic bacteria. Bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. Azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to Zn+2 and Cd+2, being Cd+2 more toxic than Zn+2. Among the most tolerant isolates (UFLA 1S, 1R, S181, S34 and S22), some (1R, S34 and S22) were more tolerant to heavy metals than rhizobia from tropical and temperate soils. The majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g L-1 NaCl. Five isolates exhibited high dissimilarity in protein profiles, and the 16S rDNA sequence analysis of two of them revealed new sequences for Azospirillum.<br>Objetivou-se avaliar a densidade de populações de bactérias diazotróficas associativas em amostras de solos e de raízes de gramíneas oriundas de sítios contaminados com metais pesados, e caracterizar isolados destas populações através da análise fenotípica (tolerância aos metais pesados zinco e cádmio e à NaCl in vitro, perfis protéicos), e genotípica (seqüenciamento de 16S rDNA), comparados às estirpes tipo das mesmas espécies. As densidades foram avaliadas nos meios NFb, Fam e LGI, comumente utilizados para culturas de enriquecimento de populações de bactérias diazotróficas associativas. As densidades encontradas em amostras de solo e raiz de sítios contaminados foram semelhantes àquelas relatadas na literatura para solos agrícolas. Isolados de Azospirillum spp. de solos contaminados e estirpes tipo oriundas de solos não contaminados variaram substancialmente com relação à tolerância a Zn+2 e Cd+2, sendo que Cd+2 mais tóxico que Zn+2. Dentre os isolados mais tolerantes (UFLA 1S, 1R, S181, S34, e S22), alguns(1R, S34 e S22) foram mais tolerantes a metais pesados que rizóbios isolados de solos de áreas tropicais e temperadas. A maioria dos isolados mais tolerantes a metais pesados também foi tolerante ao estresse salino, o que foi indicado por seu crescimento em meio sólido suplementado com 30 g L-1 de NaCl in vitro. Cinco isolados apresentaram alta dissimilaridade em perfis protéicos e o seqüenciamento do gene 16S rDNA em dois deles revelou que apresentam novas seqüências de Azospirillum

An overview of mercury contamination research in the Amazon basin with an emphasis on Brazil Uma revisão das pesquisas sobre contaminação por mercúrio na Amazônia com ênfase no território brasileiro

This article provides an overview of research on mercury contamination in the Amazon Basin and its evolution from 1990 to 2005. The assessment was based on an extensive and systematic review using bibliographic databases available online and a review of projects by research groups. Brazilian research groups were identified using the database of the Brazilian National Research Council (CNPq). A geographic information system was used to determine the location of the studies. Different aspects of mercury contamination were evaluated (environmental studies, impacts on human health, technological improvements). For 1990-2005, a total of 455 publications were identified. The main advances and remaining gaps in relation to environmental issues and human health were identified and discussed. Although the scientific output varied considerably over the period, there was a general increase in the total number of publications per year from the early 1990s (fewer than 20) until 2005 (more than 30), considering the articles published in indexed journals.<br>Esta pesquisa apresenta uma visão geral dos estudos desenvolvidos sobre a contaminação por mercúrio na bacia Amazônica e a evolução destes estudos no período 1990-2005. O estudo baseou-se em extensiva e sistemática revisão utilizando bases de dados bibliográficas disponíveis na Internet e em uma revisão dos projetos de pesquisa realizados por grupos de pesquisa. Além disso, os grupos de pesquisa brasileiros foram identificados pela base de dados do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Um sistema de informação geográfica foi usado para localizar os estudos conduzidos. Diferentes aspectos da contaminação por mercúrio na Amazônia foram analisados (estudos ambientais, impactos na saúde humana, melhorias tecnológicas). No período de 1990-2005, foram identificadas 455 publicações. As principais realizações e as lacunas existentes em relação aos estudos ambientais e de saúde humana foram identificadas e discutidas. Apesar de variações, há um aumento geral do número total de publicações por ano desde o começo da década de 1990 (menos de 20) para o final do período estudado (mais de 30), expresso por meio dos artigos publicados em revistas indexadas