Inquérito soroepidemiológico sobre a infecção chagásica em doadores de sangue na região do Alto Paranaíba, Minas Gerais

This study aimed to evaluate the seroprevalence of Trypanosoma cruzi infection in blood donors of the core of Patos de Minas Regional Foundation's Hemominas, MG. To this end, tests were used (ELISA) and Reverse Passive Hemagglutination (HPR). Through retrospective study from 1996 to 2006, was considered the result of serological 21,787 donors where 259 (1.2%) were seropositive for T. cruzi infection and the highest number of seropositivity was found in the group of 41-50 years. The total number of donors tested, 15 143 (69.5%) were male and 6644 (30.5%) females giving a seroprevalence rate of 170 (0.8%) and 89 (0.4%) respectively. This seroepidemiological survey showed that still prevail rates of transmission of Chagas disease, which reinforces the idea of the need for serological tests for the prevention of Chagas disease, especially in endemic areas as the region of Triangulo Mineiro and Alto Paranaiba.

Micropatterned nanocomposite hydrogels for biosensing applications

This paper describes the use of Au nanoparticle (NP)-containing hydrogel microstructures in the development of electrochemical enzyme-based biosensors. To fabricate biosensors, AuNPs were conjugated with glucose oxidase (GOX) or horseradish peroxidase (HRP) molecules and were dispersed in the prepolymer solution of poly(ethylene glycol) diacrylate (PEG-DA). Vinylferrocene (VF) was also added into the prepolymer solution in order to lower operating potential of the biosensor and to prevent oxidation of interfering substances. The prepolymer solution was photolithographically patterned in alignment with an array of Au electrodes fabricated on glass. As a result, electrode arrays became functionalized with AuNP/GOX- or AuNP/HRP-carrying hydrogel microstructures. Performance of the biosensors was characterized by impedance spectroscopy, chronoapmerometry and cyclic voltammetry. Impedance measurements revealed that inclusion of Au nanoparticles improved conductivity of PEG hydrogel by a factor of 5. Importantly, biosensors based on AuNP-GOX complex exhibited high sensitivity to glucose (100μAmM -1cm -2) in the linear range from 0.1 to 10mM. The detection limit was estimated to be 3.7×10- 7M at a signal-to-noise ratio of 3. Biosensors with immobilized AuNP/HPR had a linear response from 0.5 to 5.0μM of hydrogen peroxide with sensitivity of 1.4mAmM -1cm -2. The method for fabricating nanoparticle-carrying hydrogel microstructures described in this paper should be widely applicable in the development of robust and sensitive electrochemical biosensors. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Projeto e implementação de redes neurais artificiais em distintos níveis de abstrações para o reconhecimento de deficiências de diversos macronutrientes e cultivares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)