Incorporation of mineral phosphorus and potassium on leather waste (collagen): A new NcollagenPK-fertilizer with slow liberation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The feasibility of using a solid waste (rich in nitrogen) from the leather industry, after chromium extraction, as adsorbent for P and K, for possible utilization as NPK fertilizer was evaluated. The materials, with and without the addition of P and K, were characterized by chemical analyses, infrared spectroscopy, EDS (energy dispersive X-ray spectrometry) and SEM (scanning electronic microscopy). Langmuir and Freundlich equations were used for analyzing the experimental data, which showed a better fit to the Freundlich model, thus suggesting a multilayer adsorption process on the surface of the adsorbent. A preliminary test in greenhouse demonstrates that the P and K incorporation on the matrix rich in nitrogen (collagen) is a interesting alternative to use such material as NPK fertilizer. The application of NcollagenPK formulations, as a source of nutrients for the growth of rice plants, showed promising agronomic results. (C) 2009 Elsevier B.V. All rights reserved.17641699374380PREMIO SANTANDERCAPQ-DQIFundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Critical analysis of the international classification of headache disorders diagnostic criteria (ICHD I-1988) and (ICHD II-2004), for migraine in children and adolescents

The present study analyzed the (ICHD I-1988) and ( ICHD II-2004) diagnostic criteria in children and adolescents. Our population consisted of 496 patients of the Headache Outpatient Ward for Children and Adolescents retrospectively studied from 1992 to 2002. Individuals were classified according to three diagnostic groups: Intuitive Clinical Diagnosis ( Gold Standard), ICHD I-1988 and ICHD II-2004. They were statistically compared using the variables: Sensitivity ( S), Specificity (Sp), Positive Predictive Value (PPV), Negative Predictive Value (NPV). When ICHD I-1988 was used, the sensitivity of migraine without and with aura was 21% and 27%, respectively, whereas in ICHD II-2004 it changed to 53% and 71% without affecting specificity. As a conclusion, the current classification criteria ( ICHD II-2004) showed greater sensitivity and high specificity for migraine than ICHD I-1988, although it improved migraine diagnosis in children and adolescents, the sensitivity remains poor

Nb-containing hematites Fe2-xNbxO3: The role of Nb5+ on the reactivity in presence of the H2O2 or ultraviolet light

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A series of Nb-containing hematites, Fe-2-xNbxO3 (%Nb = 0.00, 1.49, 5.00 and 9.24) was prepared using the conventional co-precipitation method. Mossbauer and temperature-programmed reduction (TPR) measurements suggested the formation of the crystalline phase with partial substitution of Fe3+ by Nb5+ in the structure. N-2 adsorption/desorption revealed that the presence of Nb has a remarkable effect on the textural properties of the material with an increase in the BET surface area. The reactivity of Fe2-xNbxO3 was investigated using the oxidation of the methylene blue dye used as a model pollutant. The obtained results showed that the presence of Nb seems not to act directly promoting the H2O2 decomposition, but improving the dye oxidation. The analysis using the ESI-MS technique showed partial oxidation observed through different intermediates before the mineralization. This suggests the use of Nb-doped hematite as an efficient catalyst in degradation reactions in the presence of H2O2 or ultraviolet light. (C) 2009 Elsevier B.V. All rights reserved.35717984Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq