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  • Author or Editor: A. O. S. Silva x
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Summary  

The radionuclide 192Ir has been increasingly used as a brachytherapy source and manufactured in different geometry forms (thin wires, hairpins, needles or point sources). A procedure for the characterization of the activity content of 192Ir wire sources was developed in order to establish the secondary standard activity measurement system based on the ionization chamber set up at Brazilian National Laboratory for Ionizing Radiation Metrology (LNMRI). Firstly, the ion current of the ionization chamber is measured and, subsequently, the activity is determined in a destructive analysis. This procedure enables obtaining the calibration factor for wire sources that can be used for further activity determination of similar sources in a non-destructive analysis. Accurate activity determination is needed for dosimetric measurements and for helping the manufacturers to improve its quality control programs.

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Soymilk was fermented using Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. The soy yoghurt produced was evaluated in comparison to soymilk and commercial milk yoghurt by biological evaluation, rat growth, nitrogen balance assays and microbiological methods. Trypsin inhibitor activity and chemical composition were also determined for all samples. For the soy yoghurt, the growth and nitrogen balance values were not different from the control diet, but the nitrogen balance values were higher than for the soymilk, without significant difference in terms of growth assays. Compared to the commercial yoghurt, Net Protein Ratio and Nitrogen Utilization values were lower, but the Protein Efficiency Ratio, Biological Value and Net Protein Utilization values were equivalent, and for digestibility assays the best results were obtained with the soy yoghurt. The results indicated that soy yoghurt represents a good protein alternative to milk yoghurt and casein. The protein quality of soymilk evidently increased during the fermentation process using Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus, including a reduction in trypsin inhibitor levels of about 30%.

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Journal of Thermal Analysis and Calorimetry
Authors: J. A. Moura, A. S. Araujo, A.C. S. L. S. Coutinho, Joana M. F. B. Aquino, A. O. S. Silva, and M. J. B. Souza
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Journal of Thermal Analysis and Calorimetry
Authors: J. C. O. Santos, I. M. G. Santos, F. S. M. Sinfrônio, M. A. Silva, E. V. Sobrinho, M. M. Conceiçăo, V. J. Fernandes Jr., and A. G. Souza
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Journal of Thermal Analysis and Calorimetry
Authors: Márcia Silva, Lydianne de O. Miranda, Maria Cassia-Santos, S. Lima, L. Soledade, E. Longo, C. Paskocimas, A. Souza, and Iêda Santos

Abstract  

Undoped and/or doped with 1 mol% of Co2+ Mg2TiO4 andMg2SnO4 powders were synthesized by the polymeric precursor method. The influence of the network former (Sn4+ or Ti4+) on the thermal, structural and optical properties was investigated. The recorded mass losses are due to the escape of water and adsorbed gases and to the elimination of the organic matter. Mg2TiO4 crystallizes at lower temperatures and also presents more ordered structure with a smaller unit call and having more intense green color than Mg2SnO4 has.

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Journal of Thermal Analysis and Calorimetry
Authors: Marta M. Conceição, V. J. Fernandes Jr., F. S. M. Sinfrônio, J. C. O. Santos, M. C. D. Silva, V. M. Fonseca, and A. G. Souza
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European Journal of Microbiology and Immunology
Authors: Ingrid E. Pereira, Kyssia P. Silva, Laura M. Menegati, Aimara C. Pinheiro, Elaine A. O. Assunção, Maria De Lourdes P. Araújo, Elfadil Abass, Malcolm S. Duthie, Ulrich Steinhoff, and Henrique C. Teixeira

Abstract

Control of canine visceral leishmaniasis (CVL), a major zoonotic disease in Brazil and many other tropical and subtropical countries, remains difficult as an accurate and reliable diagnosis is still missing. In endemic regions, infected dogs are the main parasitic reservoir host of human Visceral leishmaniasis (VL) infection. Vaccination of dogs against Leishmania infection constitutes an important strategy to prevent or to better control CVL, thus, a serological test that can discriminate between antibodies induced by immunization versus infection is highly desirable in order to improve and simplify diagnosis. Here, four recombinant proteins were evaluated for their ability to detect and differentiate between dogs that are infected with Leishmania or have been immunized with the anti-Leishmania vaccine Leish-Tec®. Receiver operating characteristic (ROC) curve analysis of the four Leishmania-specific IgG ELISA revealed superior performance of rK28, followed by rKLO8, rK39 and rLb6H. The rK28-based ELISA revealed not only the best accuracy against CVL, but also the lowest cross-reactivity with sera from Leish-Tec® immunized dogs. Our data show that the rK28-based ELISA is highly suitable for CVL screening as it shows high sensitivity with simultaneous low cross-reactivity. Further, the high specificity of the rKLO8 indicates its suitability for the confirmation of CVL diagnosis.

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