Dielectric and impedance properties of Nd3/2Bi3/2Fe5O12 ceramics

The polycrystalline sample of Nd3/2Bi3/2Fe5O12 was prepared by a high- temperature solid-state reaction technique. Preliminary X-ray structural analysis exhibits the formation of a single-phase tetragonal structure at room temperature. Microstructural analysis by scanning electron microscopy shows that the sintered sample has well defined grains. These grains are distributed uniformly throughout the surface of the sample. Detailed studies of dielectric response at various frequencies and temperatures exhibit a dielectric anomaly at 400 A degrees C. The electrical properties (impedance, modulus and conductivity) of the material were studied using a complex impedance spectroscopy technique. These studies reveal a significant contribution of grain and grain boundary effects in the material. The frequency dependent plots of modulus and the impedance loss show that the conductivity relaxation is of non-Debye type. Studies of electrical conductivity with temperature demonstrate that the compound exhibits Arrhenius-type of electrical conductivity. Study of ac conductivity with frequency suggests that the material obeys Jonscher's universal power law.

IMPEDANCE CHARACTERISTICS of La3/2Bi3/2Fe5O12 CERAMICS

Polycrystalline La3/2Bi3/2Fe5O12 (LBIO) compound was prepared by a high-temperature solid-state reaction technique. The complex impedance of LBIO was measured over a wide temperature (i.e., room temperature to 500 C) and frequencies (i.e., 10(2)-10(6) Hz) ranges. This study takes advantage of plotting ac data simultaneously in the form of impedance and modulus spectroscopic plots and obey non-Debye type of relaxation process. The Nyquist's plot showed the presence of grain effects in the material at high temperature. The ac conductivity spectrum was found to obey Jonscher's universal power law. The dc conductivity was found to increase with rise in temperature. The activation energy of the compound was found to be 0.24 and 0.51 eV in the low and high-temperature region, respectively, for conduction process.

AC Conductivity and Impedance Properties of 0.65Pb(Mg1/3Nb2/3)O-3-0.35PbTiO(3) Ceramics

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância do estado de hidratação na interpretação de parâmetros nutricionais em diálise peritoneal

OBJETIVO: Identificar determinantes do estado de hidratação de pacientes em diálise peritoneal crônica, bem como investigar os efeitos da sobrecarga líquida sobre o estado nutricional. MÉTODOS: Foi feito estudo transversal, realizado em 2006, avaliando 27 pacientes em diálise peritoneal crônica, acompanhados no Hospital das Clínicas da Faculdade de Medicina de Botucatu (SP), quanto a parâmetros clínicos, dialíticos, laboratoriais, antropométricos e de bioimpedância elétrica. Para avaliar a influência de parâmetros sobre o estado de hidratação empregou-se modelo de regressão linear múltipla. A amostra foi estratificada quanto ao estado de hidratação pela relação entre água extracelular e água corporal total (0,47 para homens e 0,52 para mulheres), parâmetros obtidos por meio de bioimpedância elétrica. Comparações foram realizadas por análise de covariância, Mann-Whitney, Qui-quadrado ou teste exato de Fisher. Considerou-se significância estatística quando p≤0,05. RESULTADOS: Pacientes com maior volume urinário e em modalidade dialítica automatizada apresentaram melhor estado de hidratação. Pacientes com maior sobrecarga líquida, comparados àqueles com menor sobrecarga, apresentaram menor ângulo de fase (M=4,2, DP=0,9 vs M=5,7, DP=0,7º; p=0,006), menor albumina (M=3,06, DP=0,46 vs M=3,55, DP=0,52g/dL; p=0,05) e maior % prega cutânea tricipital (M=75,3, DP=36,9 vs M=92,1, DP=56,9%; p=0,058), sem outras evidências antropométricas. CONCLUSÃO: Pode-se sugerir que os níveis reduzidos de albumina e ângulo de fase nos pacientes com maior sobrecarga líquida não estiveram relacionados a pior estado nutricional. Para o diagnóstico nutricional em vigência de sobrecarga líquida, deve-se considerar o conjunto de variáveis obtidas por diversos métodos, buscando relacioná-las e interpretá-las de maneira abrangente, possibilitando um diagnóstico nutricional fidedigno.

The importance of knowing the home conditions of patients receiving long-term oxygen therapy

Purpose: Long-term oxygen therapy (LTOT) is one of the main treatments for patients with chronic obstructive pulmonary disease. Patients receiving LTOT may have less than optimal home conditions and this may interfere with treatment. The objective of this study was, through home visits, to identify the characteristics of patients receiving LTOT and to develop knowledge regarding the home environments of these patients.Methods: Ninety-seven patients with a mean age of 69 plus or minus 10.5 years were evaluated. This study was a cross-sectional descriptive analysis. Data were collected during an initial home visit, using a questionnaire standardized for the study. The results were analyzed retrospectively.Results: Seventy-five percent of the patients had chronic obstructive pulmonary disease, and 11% were active smokers. The patients' mean pulse oximetry values were 85.9% plus or minus 4.7% on room air and 92% plus or minus 3.9% on the prescribed flow of oxygen. Most of the patients did not use the treatment as prescribed and most used a humidifier. The extension hose had a mean length of 5 plus or minus 3.9 m (range, 1.5-16 m). In the year prior to the visit, 26% of the patients received emergency medical care because of respiratory problems. Few patients reported engaging in leisure activities.Conclusion: The home visit allowed us to identify problems and interventions that could improve the way LTOT is used. The most common interventions related to smoking cessation, concentrator maintenance and cleaning, use of a humidifier, and adjustments of the length of the connector hose. Therefore, the home visit is a very important tool in providing comprehensive care to patients receiving LTOT, especially those who show lack of adequate progress and those who show uncertainty about the treatment method.

Tratamento do transtorno de pânico com terapia psicodramática de grupo

INTRODUÇÃO/OBJETIVOS: Há poucos trabalhos publicados sobre psicoterapia grupal para pacientes com transtorno de pânico (TP); além disso, esses estudos geralmente são restritos a abordagens cognitivo-comportamentais. O objetivo deste trabalho é relatar uma experiência de atendimento psicoterápico psicodramático grupal para portadores de TP, iniciada em 1996 na Faculdade de Medicina de Botucatu/Unesp, e discutir aspectos psicodinâmicos desse transtorno. MÉTODOS: Atende-se uma média de oito a dez pacientes em sessões mensais de duas horas de duração, nas quais se utilizam técnicas psicodramáticas. O uso associado de psicofármacos é a regra. A temática é aberta, centrando-se tanto em aspectos próprios do TP (sintomas mais comuns; peregrinação em serviços médicos até o diagnóstico; preocupações hipocondríacas; limitações e dependência; reações dos familiares; estratégias de exposição e enfrentamento; efeitos e reações dos medicamentos) quanto em problemas individuais específicos. RESULTADOS: A abordagem psicodramática favorece a identificação e a elaboração de aspectos psicodinâmicos. Entre estes, destacaram-se os sentimentos de desamparo e seus desdobramentos: insegurança; fragilidade e medo; raiva e culpa; sentimentos de desamor e rejeição; vergonha e inferioridade; isolamento e dificuldade de pedir ajuda; dificuldade de identificar e de expressar sentimentos - manifestados somaticamente -; e dificuldade de assumir o papel de cuidador e outras responsabilidades. CONCLUSÕES: Aspectos valiosos para o tratamento do TP, como apoio mútuo, companheirismo, confiança, modelo e estímulo, são favorecidos pelo contexto grupal homogêneo. O compartilhar de experiências e sofrimentos comuns propiciou rápida coesão e suporte grupal, melhora da capacidade de expressar sentimentos e da auto-estima e o aprimoramento de papéis sociais. Além da melhora dos sintomas, possibilitou-se a melhor compreensão e elaboração destes, que passam a ser integrados significativamente no contexto existencial.

Plasma progesterone concentration in beef heifers receiving exogenous glucose, insulin, or bovine somatotropin

Three experiments were conducted to evaluate plasma concentrations of glucose, insulin, IGF-I, and progesterone (P4) in pubertal beef heifers receiving exogenous glucose, insulin, or sometribove zinc. All heifers used had no luteal P4 synthesis but received a controlled internal drug-releasing device containing 1.38 g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 8 pubertal, nulliparous Angus x Hereford heifers (initial BW = 442 +/- 14 kg; initial age = 656 +/- 7 d) were randomly assigned to receive, in a crossover design containing 2 periods of 10 h, intravenous (i.v.) infusions (10 mL) of insulin (1 mu g/kg of BW; INS) or saline (0.9%; SAL). Treatments were administered via jugular venipuncture in 7 applications (0.15 mu g insulin/kg BW per application) 45 min apart (from 0 to 270 min). Blood samples were collected immediately before each infusion as well as at -120, -60, 330, 390, and 450 min relative to the first infusion. Heifers receiving INS had greater (P < 0.01) plasma insulin, reduced (P <= 0.04) plasma glucose and IGF-I, and similar (P = 0.62) plasma P4 concentrations compared with SAL heifers. In Exp. 2, the same heifers were assigned to receive, in a similar experimental design as Exp. 1, i.v. infusions (10 mL) of 1) insulin (1 mu g/kg BW) and glucose (0.5 g/kg BW; INS+G) or 2) SAL. Heifers receiving INS+G had greater (P <= 0.02) plasma insulin, glucose, and P4 but reduced (P = 0.01) plasma IGF-I concentrations compared with SAL heifers. In Exp. 3, the same heifers were assigned to receive, in a crossover design containing 2 periods of 14 d, subcutaneous (s.c.) injections of 1) 250 mg of sometribove zinc (BST) or 2) SAL. Blood samples were collected 3 h apart (0900, 1200, 1500, and 1800 h) from heifers on d 6, 8, and 10 relative to treatment administration (d 1). Heifers receiving BST had greater (P < 0.01) plasma glucose and IGF-I and similar (P >= 0.67) plasma insulin and P4 concentrations compared with SAL heifers. Results from this series of experiments suggested that concurrent increases in glucose and insulin are required to reduce hepatic catabolism and increase plasma concentrations of P4 in bovine females.

Clinical and microbiological studies of children and adolescents receiving orthodontic treatment

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Oxidative stress and antioxidant capacity in sickle cell anaemia patients receiving different treatments and medications for different periods of time

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Detection of phenolic compounds using impedance spectroscopy measurements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilization of electrochemical impedance spectroscopy for monitoring bornite (CU5FeS4) oxidation by Acidithiobacillus ferrooxidans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Electrochemical impedance spectroscopy as a tool to estimate thickness in PB films

The analysis of the faradaic impedance of electroactive films provides a characteristic point from which it is possible to estimate the thickness of thin films. Thus, electrochemical impedance spectroscopy was used in this paper as a fast and easy technique to estimate this thickness. The proposed method was checked on PB films. (c) 2006 Elsevier B.V. All rights reserved.

Corrosion of the component phases presents in high copper dental amalgams. Application of electrochemical impedance spectroscopy and electrochemical noise analysis

The corrosion resistance of three of the constituent phases in high copper dental amalgams has been investigated by electrochemical methods in 0.9% NaCl solution. Polarization curves show corrosion potentials most positive for gamma(1)-Ag2Hg3, followed by Ag-Cu, and gamma-Ag3Sn in agreement with the order of corrosion resistance deduced from the corrosion currents. Complex plane impedance plots at the open circuit potential showed distorted semicircles with diffusional components at low frequency for Ag-Hg and Ag-Cu, while for gamma-Ag3Sn a layer of corrosion products is formed, partially or completely covering the surface of the electrode. Impedance and noise spectra have been compared in the frequency domain, and show good agreement. (C) 2004 Elsevier Ltd. All rights reserved.