Rare earth element and yttrium geochemistry applied to the genetic study of cryolite ore at the Pitinga Mine (Amazon, Brazil)

This work aims at the geochemical study of Pitinga cryolite mineralization through REE and Y analyses in disseminated and massive cryolite ore deposits, as well as in fluorite occurrences. REE signatures in fluorite and cryolite are similar to those in the Madeira albite granite. The highest ΣREE values are found in magmatic cryolite (677 to 1345 ppm); ΣREE is lower in massive cryolite. Average values for the different cryolite types are 10.3 ppm, 6.66 ppm and 8.38 ppm (for nucleated, caramel and white types, respectively). Disseminated fluorite displays higher ΣREE values (1708 and 1526ppm) than fluorite in late veins(34.81ppm). Yttrium concentration is higher in disseminated fluorite and in magmatic cryolite. The evolution of several parameters (REEtotal, LREE/HREE, Y) was followed throughout successive stages of evolution in albite granites and associated mineralization. At the end of the process, late cryolite was formed with low REEtotal content. REE data indicate that the MCD was formed by, and the disseminated ore enriched by (additional formation of hydrothermal disseminated cryolite), hydrothermal fluids, residual from albite granite. The presence of tetrads is poorly defined, although nucleated, caramel and white cryolite types show evidence for tetrad effect.Este trabalho enfoca a geoquímica de elementos terras raras (ETR) e de Y no minério criolítico disseminado, no depósito criolítico maciço e na fluorita associada na mina Pitinga. As assinaturas de ETR na criolita e fluorita são similares àquelas do granito Madeira. Os maiores valores de SETR são encontrados na criolita magmática disseminada (677 a 1.345 ppm); SETR é menor na criolita maciça, com valores médios de 10,3 ppm, 6,66 ppm e 8,38 ppm, respectivamente, nos tipos de criolita nucleada, caramelo e branca. A fluorita magmática disseminada apresenta os valores mais altos de SETR (1.708 e 1.526 ppm), contrastando com a fluorita de veio tardio(34,81 ppm). A concentração de Y é maior na fluorita disseminada e na criolita magmática. As evoluções de diversos parâmetros (SETR, ETRL/ETRP, Y) podem ser seguidas através dos sucessivos estágios de evolução dos albita granitos e mineralização associada. Os dados de ETR indicam que o depósito criolítico maciço foi formado por, e o minério disseminado enriquecido por (formação adicional criolita disseminada hidrotermal), fluidos hidrotermais residuais do albita granito. A presença do efeito tetrad não é bem definida, embora as criolitas maciças nucleada, caramelo e branca apresentem algumas evidências deste efeito.FINEPAgência para o Desenvolvimento da Indústria Mineral do BrasilConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) - Departamento Nacional de Produção MineralFundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS) - Programa de Apoio a Núcleos de ExcelênciaCNP

Purification, characterization and structural determination of UDP-N-acetylglucosamine pyrophosphorylase produced by Moniliophthora perniciosa

The enzyme UDP-N-acetylglucosamine pyrophosphorylase (PyroMp) from Moniliophthora perniciosa (CCMB 0257), a pathogenic fungal strain and the causative agent of the witches' broom disease in Theobroma cacao, was partially purified by precipitation with ammonium sulfate and gel filtration on Sephacryl S-200. The buffer for enzyme extraction was sodium phosphate, 0.050 mol L-1, pH 7.0, containing 1.0 mol L-1 NaCl. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes (PyroMp I, PyroMp II, PyroMp III and PyroMp IV) were obtained with optimal pH ranging from 6.9-8.4 and optimum temperature ranging from 28 to 68 °C. The 3D structure of pyrophosphorylase of M. perniciosa was determined by comparative modeling. The model obtained showed a good quality, possessing 78.6% of amino acids in energetically allowed regions. The model was then submitted for DM simulation and showed a good geometric quality (91.1% Ramachandran plot). The active site of the enzyme was found to be extremely well conserved. This model will be useful for developing new inhibitors against witches' broom disease22610151023CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DA BAHIA - FAPESBFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãoA enzima UDP-N-acetilglicosamina pirofosforilase de Moniliophthora perniciosa (CCMB 0257), o fungo patogênico causador da doença vassoura-de-bruxa do Theobroma cacao, foi parcialmente purificada por precipitação com sulfato de amônio e cromatografia de gel filtração em Sephacryl S-200. O tampão de extração da enzima foi o fosfato de sódio, 0,050 mol L-1, pH 7,0, contendo 1,0 mol L-1 de NaCl. A metodologia de superfície de resposta (MSR) foi usada para a obtenção do pH e temperatura ótima. Os resultados mostraram quatro diferentes isoenzimas (PyroMp I, PyroMp II, PyroMp III e PyroMp IV) que apresentaram pH ótimo na faixa de 6,9-8,4 e temperatura ótima variando entre 28 a 68 °C. A estrutura 3D de pirofosforilase de M. perniciosa foi obtida por modelagem comparativa. O modelo obtido mostrou uma boa qualidade, possuindo 78,6% de aminoácidos nas regiões energeticamente favoráveis. O modelo foi então submetido a simulações de dinâmica molecular (DM). O modelo apresentou uma boa qualidade geométrica após as simulações de DM (91,1% -gráfico de Ramachandran). A procura pelo sítio ativo da enzima mostrou que este é mantido extremamente conservado. Este modelo pode ser útil para desenvolvimento de inibidores contra a doença vassoura de brux

Purification, characterization and structural determination of UDP-N-acetylglucosamine pyrophosphorylase produced by Moniliophthora perniciosa

The enzyme UDP-N-acetylglucosamine pyrophosphorylase (PyroMp) from Moniliophthora perniciosa (CCMB 0257), a pathogenic fungal strain and the causative agent of the witches' broom disease in Theobroma cacao, was partially purified by precipitation with ammonium sulfate and gel filtration on Sephacryl S-200. The buffer for enzyme extraction was sodium phosphate, 0.050 mol L-1, pH 7.0, containing 1.0 mol L-1 NaCl. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes (PyroMp I, PyroMp II, PyroMp III and PyroMp IV) were obtained with optimal pH ranging from 6.9-8.4 and optimum temperature ranging from 28 to 68 °C. The 3D structure of pyrophosphorylase of M. perniciosa was determined by comparative modeling. The model obtained showed a good quality, possessing 78.6% of amino acids in energetically allowed regions. The model was then submitted for DM simulation and showed a good geometric quality (91.1% Ramachandran plot). The active site of the enzyme was found to be extremely well conserved. This model will be useful for developing new inhibitors against witches' broom disease.A enzima UDP-N-acetilglicosamina pirofosforilase de Moniliophthora perniciosa (CCMB 0257), o fungo patogênico causador da doença vassoura-de-bruxa do Theobroma cacao, foi parcialmente purificada por precipitação com sulfato de amônio e cromatografia de gel filtração em Sephacryl S-200. O tampão de extração da enzima foi o fosfato de sódio, 0,050 mol L-1, pH 7,0, contendo 1,0 mol L-1 de NaCl. A metodologia de superfície de resposta (MSR) foi usada para a obtenção do pH e temperatura ótima. Os resultados mostraram quatro diferentes isoenzimas (PyroMp I, PyroMp II, PyroMp III e PyroMp IV) que apresentaram pH ótimo na faixa de 6,9-8,4 e temperatura ótima variando entre 28 a 68 °C. A estrutura 3D de pirofosforilase de M. perniciosa foi obtida por modelagem comparativa. O modelo obtido mostrou uma boa qualidade, possuindo 78,6% de aminoácidos nas regiões energeticamente favoráveis. O modelo foi então submetido a simulações de dinâmica molecular (DM). O modelo apresentou uma boa qualidade geométrica após as simulações de DM (91,1% -gráfico de Ramachandran). A procura pelo sítio ativo da enzima mostrou que este é mantido extremamente conservado. Este modelo pode ser útil para desenvolvimento de inibidores contra a doença vassoura de bruxa.FINEPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqFAPESBFIOCRUZ - Programa de Pós-Graduação em Biotecnologia UEF

Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study

Purification, characterization and structural determination of chitinases produced by Moniliophthora perniciosa

The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV. ChitMp I had an optimum temperature at 44-73ºC and an optimum pH at 7.0-8.4. ChitMp II had an optimum temperature at 45-73ºC and an optimum pH at 7.0-8.4. ChitMp III had an optimum temperature at 54-67ºC and an optimum pH at 7.3-8.8. ChitMp IV had an optimum temperature at 60ºC and an optimum pH at 7.0. For the computational biology, the primary sequence was determined in silico from the database of the Genome/Proteome Project of M. perniciosa, yielding a sequence with 564 bp and 188 amino acids that was used for the three-dimensional design in a comparative modeling methodology. The generated models were submitted to validation using Procheck 3.0 and ANOLEA. The model proposed for the chitinase was subjected to a dynamic analysis over a 1 ns interval, resulting in a model with 91.7% of the residues occupying favorable places on the Ramachandran plot and an RMS of 2.68

Acute norovirus gastroenteritis in children in a highly rotavirus-vaccinated population in Northeast Brazil.

Background: Gastroenteritis is one of the most important causes of morbidity and mortality in children and an important etiological agent is norovirus. Objective: We describe the occurrence and characteristics of norovirus diarrhoea in children from Sergipe, Northeast-Brazil, over two consecutive periods of three years following rotavirus vaccine introduction. Study design: A cross sectional hospital-based survey conducted from October-2006 to September-2009 and from July-2011 to January-2013. Acute diarrhoea cases had a stool sample collected and tested for norovirus by RT-PCR and positive samples were sequenced. Results: In total 280 (19.6%) of 1432 samples were norovirus positive, including 204 (18.3%) of 1,113 samples collected during the first period and 76 (23.9%) of 318 collected during the second period. The proportion of children with norovirus infection increased significantly through the second study period (χ2 for trend = 6.7; p = 0.009), was more frequent in rotavirus vaccinated and in younger children (p < 0.001). Of 280 norovirus-positive specimens, 188 (67.1%) were sequenced. Of these, 12 were genogroup I and 176 genogroup II. The main genotype was GII.4 (149/188, 79.3%), followed by GII.2 (6, 3.2%) and GII.6 (5, 2.6%). Conclusion: Norovirus annual detection rates increased over the study period. The detection of norovirus was higher among young children