Otimização de um ciclo Brayton irreversível com regeneração, inter-resfriamento e reaquecimento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Informação e tecnologia para implantação do agroturismo em Echaporã - SP

Pós-graduação em Ciência da Informação - FFC

Perfil clínico dos animais e funcionalidade do uso do aparelho de fisioterapia veterinária(modelos vetcar) na reabilitação de cães e gatos acometidos por dificuldades de locomoção

Pós-graduação em Medicina Veterinária - FMVZ

Efeito da revascularização renal sobre a evolução da disfunção renal na nefropatia isquêmica aterosclerótica

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Análise dos níveis de ruído produzidos pelas canetas de alta rotação nas freqüências de bandas de oitavas e as atenuações dos protetores auriculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do exercício de agachamento utilizando o método de Kane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito protetor da vitima E(ɑ-TOCOFEROL) contra a atividade citotóxica do peróxido de hidrogenênio

Pós-graduação em Reabilitação Oral - FOAR

Electrochemical feasibility study of methyl parathion determination on graphite-modified basal plane pyrolytic graphite electrode

A low-cost electrochemical method was developed for the determination of trace-level of methyl parathion (MP) based on the properties of graphite-modified basal plane pyrolytic graphite electrode (graphite-bppg). A combination of graphite-bppg with square-wave voltammetric (SWV) analysis resulted in an original, sensitive and selective electrochemical method for determination of MP pesticide in drinking water. The electrode was constructed and the electrochemical behavior of MP was studied. Immobilization is achieved via film modification from dispersing graphite powder in deionized water and through pipeting a small volume onto the electrode surface allowing the solvent to volatilize. The strong affinity of the graphite modifier for the phosphorous group of the MP allowed the deposition of a significant amount of MP in less than 60 seconds. The cyclic voltammetric results indicate that the graphite-bppg electrode can enhance sensitivity in current intensity towards the quasi-reversible redox peaks of the products of the cathodic reduction of the nitro group at negative potential (peak I = 0.077 V and peak II = –0.062 V) and that the cathodic irreversible peak (peak III = –0.586 V) in comparison with bare bppg electrode and is also adsorption controlled process. Under optimized conditions, the concentration range and detection limit for MP pesticide are respectively 79.0 to 263.3 mmol L-1 and 3.00 mmol L-1. The proposed method was successfully applied to MP determination in drinking water and the performance of this electrochemical sensor has been evaluated in terms of analytical figures of merit.

Determination of tetradifon in brazilian green bell pepper by differential pulse voltammetry

Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) technique on a glassy carbon electrode is proposed. The electrochemical behavior of tetradifon as followed by cyclic voltammetry (CV) suggests that its reduction occurs via an irreversible five–electron transfer vs. Ag|AgCl, KCl 3 M reference electrode. Very well–resolved diffusion controlled voltammetric peaks have been obtained in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L−1 at −1.43, −1.57, −1.73, −1.88, and −2.05 V. The proposed DPV method has a good linear response in the 3.00 – 10.0 μmol L−1 range, with a limit of detection (L.O.D) of 0.756 μmol L−1 and 0.831 μmol L−1 in the absence and in the presence of the matrix, respectively. Moreover, improved L.O.D results (0.607 μmol L−1) have been achieved in the absence of DMF from the supporting electrolyte solution. Recovery has been evaluated in five commercial green bell pepper samples, and recovery percentages ranging from 91.0 to 109 have been obtained for tetradifon determinations. The proposed voltammetric method has also been tested for reproducibility, repeatability, and potential interferents, and the results obtained for these three analytical parameters are satisfactory for electroanalytical purposes.

New voltammetry-based technique for the determination of tebuthiuron in crystal and brown sugar samples

Sugar is widely consumed worldwide and Brazil is the largest producer, consumer, and exporter of this product. To guarantee proper development and productivity of sugar cane crops, it is necessary to apply large quantities of agrochemicals, especially herbicides and pesticides. The herbicide tebuthiuron (TBH) prevents pre- and post-emergence of infesting weed in sugarcane cultures. Considering that it is important to ensure food safety for the population, this paper proposes a reliable method to analyse TBH in sugar matrixes (brown and crystal) using square wave voltammetry (SWV) and differential pulse voltammetry (DPV) at bare glassy carbon electrode and investigate the electrochemical behavior of this herbicide by cyclic voltammetry (CV). Our results suggest that TBH or the product of its reaction with a supporting electrolyte is oxidized through irreversible transfer of one electron between the analyte and the working electrode, at a potential close to +1.16 V vs. Ag |AgClsat in 0.10 mol L-1 KOH as supporting electrolyte solution. Both DPV and SWV are satisfactory for the quantitative analysis of the analyte. DPV is more sensitive and selective, with detection limits of 0.902, 0.815 and 0.578 mg kg-1, and quantification limits of 0.009, 0.010 and 0.008 mg kg-1 in the absence of the matrix and in the presence of crystal and brown sugar matrix, respectively. Repeatability lay between 0.53 and 13.8%, precision ranged between 4.14 and 15.0%, and recovery remained between 84.2 and 113% in the case of DPV conducted in the absence of matrix and in the presence of the crystal sugar matrix, respectively.

New voltammetry-based analytical method for indirect determination of procymidone in brazilian apples

Procymidone, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to apple crops. In this work, we propose a reliable and sensitive method to determine procymidone in Brazilian apples. The method involves differential pulse (DPV) and square-wave voltammetry (SWV) techniques on a glassy carbon electrode. In a supporting electrolyte solution of 0.5 mol L−1 NaOH, procymidone undergoes an irreversible one-electron oxidation at +1.42 V by cyclic voltammetric vs. Ag|AgCl, KCl 3 M reference electrode. The proposed DPV and SWV methods have a good linear response in the 8.00–20.0 mg L−1 range, with limits of detection (LOD) of 0.678 and 0.228 mg L−1, respectively, in the absence of the matrix. We obtained improved LOD (0.097 mg L−1) in the presence of apple matrix and the supporting electrolyte solution. We used three commercial apple samples to evaluate recovery, and we achieved recovery percentages ranging from 94.6 to 110 % for procymidone determinations. We also tested the proposed voltammetric method for reproducibility, repeatability, and potential interferents, and the results were satisfactory for electroanalytical purposes.

Achados clínicos e radiográficos das doenças endócrinas de interesse estomatológico

Pós-graduação em Biopatologia Bucal - ICT

Efeito citotóxico da Terapia Fotodinâmica associando Photogem e LED azul e vermelho em cultura de células normais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da adição de colesterol sobre a viabilidade e fertilidade de espermatozóides equinos refrigerados

Pós-graduação em Medicina Veterinária - FMVZ

Population ageing in the Caribbean: An inventory of policies, programmes and future challenges

“We must be fully aware that while the developed countries became rich before they became old, the developing countries will become old before they become rich”. This statement made by Gro Harlem Brundtland, World Health Organization (WHO) Director-General, at the World Assembly on Ageing in 2002 in Madrid, reflects the challenges that the developing world is facing in the twentieth century. Population ageing is a global phenomenon, which is having and will have major implications on all aspects of human life in every society. This process is enduring and irreversible, as observed from differing patterns and distinct paces in various regions and countries all over the world. The United Nations has undertaken various efforts to repeatedly draw governments’ attention to the growing demand for answers to these encompassing and profound demographic changes. Various initiatives on the global as well as on the regional and subregional level have been undertaken to highlight the pressing need for concerted action. Of importance in this regard are the numerous agreements reached at the global conferences on social development, population and women orchestrated by the United Nations in the 1990s, which all refer to ageing as an issue of particular concern. The year 1999 was proclaimed by the General Assembly1 of the United Nations as the Year of Older Persons to recognize ageing as one of the major achievements but, at the same time, as one of the major challenges all populations have to cope with in the twentieth century. This continuous call for action culminated in the Second World Assembly on Ageing, which was held in Madrid 2002, where governments agreed to the implementation of a global action plan. This new Plan of Action focuses both on political priorities such as improvements in living conditions of older persons, combating poverty, social inclusion, individual self-fulfilment, human rights and gender equality. To an increasing degree attention is also devoted to such holistic and overarching themes as intergenerational solidarity, employment, social security, health and well-being. Mandated by the Second World Assembly on Ageing, the Population Division of the Economic Commission for Latin America and the Caribbean (ECLAC/CELADE) has convened the Regional Intergovernmental Conference on Ageing in November 2003 in Santiago, where a regional strategy for the implementation (ECLAC, 2003b) of the commitments reached in Madrid has been adopted. Further, a background document (ECLAC 2003a) on the situation of the elderly in the Latin American and Caribbean region, of which this document is a substantive part, has been presented to the meeting. Participating government officials formally committed themselves to work on a national follow-up strategy and to report on the progress made in the implementation of their commitments to the Ad hoc Committee on Population and Development to be convened in 2004.