UVC emitting phosphors obtained by spray pyrolysis

The broadband inter-configurational (4f(1)5d(1)-->4f(2)) emission of Pr(3+) doped in lanthanum orthophosphate (LaPO(4)) and in calcium pyrophosphate (Ca(2)P(2)O(7)) has been investigated under plasma excitation. The synthesis by spray pyrolysis at moderate temperature followed by a controlled annealing proves to be a very efficient way to produce good quality UVC emitting phosphor Ca(1.92)Pr(0.04)Na(0.04)P(2)O(7) (alpha phase). The emission of this phosphor in the wavelength range 200-350 nm has been measured with a prototype device, which can be employed for anti-microbial testing. (C) 2010 Elsevier B.V. All rights reserved.

Analytical Methods in Photoelectrochemical Treatment of Phenol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Photocatalytic Degradation of Phenol by Thermal Titanium Dioxide Thin Layer Electrodes

Electrochemical processes in industrial effluents have been studied as a means to obtain higher efficiency in wastewater treatment. Heterogeneous photocatalysis appears as a low-cost alternative through the use of lower wattage lamps and thermal TiO2 films. Photocatalysis became a clean process for water treatment due to hydroxyl radicals generated on semiconductor surface. Such radicals are able to degrade several organic compounds. This study used different electrodes and analytical methods for degradation of phenol molecules to reduce treatment costs, improve efficiency, and identify compounds formed during the decomposition of phenolic molecules. Thermal growth of TiO2 film was observed on the titanium electrode in rutile form. Application of an electrical potential on the Ti/TiO2 working electrode increases efficiency in reducing concentration of phenol after photocatalytic treatment. Still, high energy radiation (UVC) showed best degradation rates in photolytic process. Different compounds formed during the degradation of phenol were also identified in the UVC-PE treatment.

Síntese e caracterização de intermetálicos ordenados binários de ouro: potenciais eletrocatalisadores de reações em células à combustível

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Desenvolvimento de métodos analíticos para estudos de estabilidade para fluconazol cápsulas

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

Atividade antioxidante, compostos fenólicos totais e cor em abacate ‘hass’ submetido a diferentes tratamentos físicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de Reparo de DNA e Atividade Antioxidante do Extrato Etanólico e Substâncias Isoladas de Casearia sylvestris

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

O papel da argila na estabilização térmica de nanocompósitos: um estudo da ordem local e a média distância

Pós-graduação em Química - IQ

Verres et vitrocéramiques à base de chalco: halogénures dopés par des ions de terres rares pour la luminescence dans le visible

Pós-graduação em Química - IQ

Processamento e propriedades magnéticas de manganitas multiferróicas = Mise en forme et propriétés magnétiques de manganites multiferróïques

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Utilização de luz ultravioleta contínua (UV-C) e luz pulsada para conservação de mangas CV. Tommy Atkins minimamente processadas

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Desenvolvimento e validação do método de difusão em ágar para quantificação de fluconazol cápsulas e aplicação em estudos de estabilidade

O fluconazol é um antifúngico de amplo espectro indicado para o tratamento de infecções fúngicas sistêmicas e superficiais. A determinação da potência dos antimicrobianos é importante no controle e na garantia da qualidade das preparações farmacêuticas e faz-se necessário o desenvolvimento de procedimentos práticos e econômicos que possam ser validados e aplicados no doseamento desses fármacos. Dentre os ensaios microbiológicos, os mais comumente empregados são o de difusão em ágar e o turbidimétrico. O objetivo deste trabalho foi desenvolver e validar métodos microbiológicos para determinação da potência do fluconazol cápsulas. O método de difusão em ágar foi desenvolvido empregando ágar Sabouraud e Candida albicans ATCC 64548 como micro-organismo teste. Foi utilizado o delineamento 3 x 3, segundo preconiza a Farmacopeia Brasileira (2010). A validação do método demonstrou linearidade entre o diâmetro dos halos de inibição e o logaritmo da concentração numa faixa de 25,0 a 100,0 µg/mL. Os resultados foram precisos, com desvio padrão relativo igual a 6,15%, e exatos, com intervalo de tolerância de 97,30%, dentro dos limites permitidos. O método foi aplicado ainda em estudos de estabilidade, nas condições de estresse calor úmido, em câmara climática a 40 ºC e 75% de umidade relativa por 90 dias; calor seco, em estufa a 60 ºC por 66 dias e fotodegradação, em câmara espelhada com luz UVC por 66 e 180 dias. Os valores de teor médio calculados foram de 30,27% para calor úmido; 27,72% para calor seco; 33,29% para fotodegradação durante 66 dias e 25,00% para fotodegradação durante 180 dias

Tetraethylortossilicate plasma thin film with hydrophilic and hydrophobic characteristics: Use on passive mixers

This work aims to obtain plasma thin film composites with hydrophobic/hydrophilic alternated regions, which are useful for the production of miniaturized mixers. These regions were acquired by two different strategies: either the codeposition of TEOS and HFE plasma thin films or the exposition of TEOS plasma films to ultraviolet radiation (UVA and UVC). These films were characterized by several chemical and physical techniques. The refractive indexes vary from 1.4 to 1.7; infrared and photoelectron spectroscopy detect Si-O-Si and CHn species. Silicone-like structures with high or low number of amorphous carbon microparticles and with fluorinated organic clusters were produced. Cluster dimensions were in the 1-5 mm range and they are made of graphite or COF (carbon/oxygen/fluorine) compounds. Scanning electron and optical microscopy showed rough surfaces. Water contact angles were 90º; however, for TEOS films that value changed after 6 hr of UVC exposure. Moreover, after UV exposure, organic polar compounds could be adsorbed in those films and water was not. The passive mixer performance was simulated using the FemLab 3.2® program and was tested with 20 nm thick films on a silicon wafer, showing the capacity of these films to be used in such devices.

Estudo das células mononucleares e polimorfonucleares no intestino de cães naturalmente infectados por leishmania infantum

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Stability study of fluconazole applying validated bioassay and stability-indicating LC methods

Chemical degradation of drugs may result in altered therapeutic efficacy and even toxic effects. Therefore, understanding the factors that change the stability of pharmaceuticals and identifying ways to guarantee their stability are important. In this work stability-indicating Liquid Chromatographic (LC) and bioassay methods were validated and employed in the fluconazole stability studies. The correlation of sample results from both methods was evaluated. Fluconazole raw material stability was investigated in aqueous, acid (0.1 M HCl), alkaline (0.1 M NaOH) and oxidative (3% v/v H2O2) reflux for 6 hours, by LC method. Fluconazole capsules were exposed to UVC (254 nm, 66 and 180 days), climatic chamber (40°C, 75% RH, 90 days) and oven (60°C, 60 days), these samples were analyzed by LC and bioassay methods It was found that the drug is degraded (10% decrease) with arising of a possible degradation product in an oxidative medium and UVC exposure, in all the others conditions fluconazole remained chemically stable (higher than 98%) when analyzed by LC. However when the capsules stressed samples were evaluated through bioassay very low antifungal activity was found (about 30%). Fluconazole showed to be an unstable drug and it indicates that special care must be taken during the handling, storage and quality control using appropriated methods to analyze this therapeutic agent. This work suggests monitoring the fluconazole stability by bioassay and the stability-indicating LC methods.