82 research outputs found

    Investigating the binding heterogeneity of trace metal cations with SiO2 nanoparticles using full wave analysis of stripping chronopotentiometry at scanned deposition potential

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    Silica oxides nano- and microparticles, as well as silica-based materials, are very abundant in nature and industrial processes. Trace metal cation binding with these bulk materials is generally not considered significant in speciation studies in environmental systems. Nonetheless, this might change for nanoparticulate systems as observed in a previous study of Pb(II) with a very small SiO2 particle (7.5 nm diameter). Besides, metal binding by those nanoparticles is surprisingly characterized by a heterogeneity that increases with the decrease of metal-to-particle ratio. Therefore, it is interesting to extend this study to investigate different trace metals and the influence of the nanoparticle size on the cation binding heterogeneity. Consequently, the Cd(II), Pb(II), and Zn(II) binding by two different sized SiO2 nanoparticles (Ludox LS30 and TM40) in aqueous dispersion was studied for a range of pH and ionic strength conditions, using the combination of the electroanalytical techniques Scanned Stripping ChronoPotentiometry and Absence of Gradients and Nernstian Equilibrium Stripping. The coupling of these techniques provides the free metal concentration in the bulk (AGNES) and information of the free and complex concentration at the electrode surface for each Stripping Chronopotentiometry at Scanned deposition Potential (SSCP). A recent mathematical treatment allows the reconstruction of a portion of the metal to ligand binding isotherm with the included heterogeneity information using the full SSCP wave analysis. In this work, we observed that the Zn(II) binding is homogeneous, Cd(II) is slightly heterogeneous, and Pb(II) is moderately heterogeneous, whereas the results obtained with the 7.5 nm diameter nanoparticle are slightly more heterogeneous than those obtained with the one of 17 nm. These findings suggest that the Zn(II) binding is electrostatic in nature, and for both Cd(II) and Pb(II), there should be a significant chemical binding contribution.FCT-ANR/AAG-MAA/0065/2012info:eu-repo/semantics/publishedVersio

    'Atypical' bacteria are a common cause of community-acquired pneumonia in hospitalised adults

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    Objectives. To assess the proportion of cases of community· acquired pneumonia caused by 'atypical' bacteria, inclUding the recently discovered Chlamydia pneumoniae, and to compare the clinical, radiographic and laboratory features of patients with and without 'atypical' bacteria.Methods. A prospective serological study was carried out on consecutive adult pneumonia patients from July 1987 to July 1988. Acute and convalescent sera were tested in batches for antibodies against Legionella pneumophila serogroup 1, C. pneumoniae, Chlamydia psittaci, Coxiella burnetii (phase-2 antigen) and Mycoplasma pneumoniae (lgG and IgM). Records and chest radiographs were examined retrospectively.Results. Acute and convalescent sera were available from 113 patients. The records of 4 patients could not be traced and 17 patients did not fulfil the inclusion criteria. Thirty-two of these 92 patients (35,9%) were found to be infected with 'atypical' bacteria. The two most common organisms were C. pneumoniae (20,7%) and L. pneumophila (8,7%). There. were no differences in the clinical and radiographic features of patients with and without 'atypical' bacteria. Clinicians prescribed erythromycin or tetracyclines with equal frequency in the two groups.Conclusions. 'Atypical' bacteria, especially C. pneumoniae, are a common cause of community-acquired pneumonia in adults in South Africa. This is the first demonstration of an aetiological role of C. pneumoniae in this country. We confirmed the finding of other studies that there are no clinical, radiographic or laboratory features characteristic of 'atypical' bacterial infection in hospitalised patients. This has major implications for therapy, as these organisms respond to erythromycin and tetracyclines, but· not to β-lactam antibiotics

    Associação de marcadores moleculares do BTA14 com espessura de gordura em bovinos da raça Canchim.

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    Efficacy of the Pentavalent Rotavirus Vaccine, RotaTeq (RV5), Between Doses of a 3-Dose Series and With Less Than 3 Doses (Incomplete Regimen)

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    Post-hoc analyses of the Rotavirus Efficacy and Safety Trial (RES T) were conducted to determine whether the pentavalent rotavirus vaccine (RV5) confers early protection against rotavirus gastroenteritis (RVGE) before completion of the 3-dose regimen. To evaluate the efficacy of RV5 between doses in reducing the rates of RVGE-related hospitalizations and emergency department (ED) visits in infants who ultimately received all 3 doses of RV5/placebo, events occurring from 2 weeks after the first and second doses to receipt of the subsequent dose (Analysis A) and events occurring from 2 weeks after the first and second doses to 2 weeks after the subsequent dose (Analysis B) were analyzed. In Analysis A, RV5 reduced the rates of combined hospitalizations and ED visits for G1-G4 RVGE or RVGE regardless of serotype between doses 1 and 2 by 100% [95% confidence interval (CI): 72-100%] or 82% (95% CI: 39-97%), respectively, and between doses 2 and 3, RV5 reduced the rates of combined hospitalizations and ED visits for G1-G4 RVGE or RVGE regardless of serotype by 91% (95% CI: 63-99%) or 84% (95% CI: 54-96%), respectively. Similar rate reductions were observed in Analysis B. These data suggest that RV5 provides a high level of protection between doses against hospitalizations and ED visits for RVGE starting as early as 14 days after the first dose

    Public Health Impact and Cost-Effectiveness of Hepatitis A Vaccination in the United States: A Disease Transmission Dynamic Modeling Approach

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    Objective: To assess the population-level impact and costeffectiveness of hepatitis A vaccination programs in the United States. Methods: We developed an age-structured population model of hepatitis A transmission dynamics to evaluate two policies of administering a twodose hepatitis A vaccine to children aged 12 to 18 months: 1) universal routine vaccination as recommended by the Advisory Committee on Immunization Practices in 2006 and 2) Advisory Committee on Immunization Practices's previous regional policy of routine vaccination of children living in states with high hepatitis A incidence. Inputs were obtained from the published literature, public sources, and clinical trial data. The model was fitted to hepatitis A seroprevalence (National Health and Nutrition Examination Survey II and III) and reported incidence from the National Notifiable Diseases Surveillance System (1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995). We used a societal perspective and projected costs (in 2013 US ),qualityadjustedlifeyears,incrementalcosteffectivenessratio,andotheroutcomesovertheperiod2006to2106.Results:Onaverage,universalroutinehepatitisAvaccinationprevented259,776additionalinfections,167,094outpatientvisits,4781hospitalizations,and228deathsannually.Comparedwiththeregionalvaccinationpolicy,universalroutinehepatitisAvaccinationwascostsaving.Inscenarioanalysis,universalvaccinationprevented94,957infections,46,179outpatientvisits,1286hospitalizations,and15deathsannuallyandhadanincrementalcosteffectivenessratioof), qualityadjusted life-years, incremental cost-effectiveness ratio, and other outcomes over the period 2006 to 2106. Results: On average, universal routine hepatitis A vaccination prevented 259,776 additional infections, 167,094 outpatient visits, 4781 hospitalizations, and 228 deaths annually. Compared with the regional vaccination policy, universal routine hepatitis A vaccination was cost saving. In scenario analysis, universal vaccination prevented 94,957 infections, 46,179 outpatient visits, 1286 hospitalizations, and 15 deaths annually and had an incremental cost-effectiveness ratio of 21,223/quality-adjusted life-year when herd protection was ignored. Conclusions: Our model predicted that universal childhood hepatitis A vaccination led to significant reductions in hepatitis A mortality and morbidity. Consequently, universal vaccination was cost saving compared with a regional vaccination policy. Herd protection effects of hepatitis A vaccination programs had a significant impact on hepatitis A mortality, morbidity, and cost-effectiveness ratios

    Predicted genetic gains weighted by selection pressures for grain quality in irrigated rice.

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    O objetivo deste trabalho foi analisar componentes de variâncias e herdabilidades, estimar o ganho de seleção e avaliar as diferentes pressões de seleção para atributos físicos de qualidade de grãos de famílias de gerações segregantes de arroz (Oryza sativa) irrigado, por meio da metodologia REML/BLUP. O experimento foi conduzido no Rio Grande do Sul, Brasil, onde foram realizadas seleções nas gerações segregantes F3, F4 e F5, nas safras 2015/2016, 2016/2017 e 2017/2018, em oito populações segregantes (famílias) oriundas de diferentes cruzamentos. Foram avaliados atributos físicos de qualidade intrínsecos, parâmetros genéticos e resposta à seleção, tendo-se utilizado diferentes pressões de seleção. Foram obtidas estimativas que apresentaram ganhos genéticos para os caracteres de qualidade dos grãos, principalmente para área calcárea total, alvura vítrea, alvura total, relação entre alvura vítrea e alvura total, e percentual de grãos inteiros e quebrados, em seleções nas primeiras gerações. As famílias utilizadas apresentam resultados satisfatórios, sendo superiores às cultivares-controle. Para a maioria dos caracteres, as estimativasde herdabilidade em sentido amplo são consideradas intermediárias, junto com os demais parâmetros, o que mostra a possibilidade de seleção genética para os atributos de qualidade do grão. A resposta à seleção com pressão de 10% é muito promissora para os atributos de qualidade de grãos de arroz.Título em português: Ganhos genéticos previstos ponderados por pressões de seleção para qualidade de grãos em arroz irrigado

    GeoNode-BR: comunidade brasileira para a colaboração entre usuários do software GeoNode.

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    O GeoNode é uma solução web para o gerenciamento de recursos espaciais [1], e para a implantação de Infraestruturas de Dados Espaciais (IDEs). É uma solução livre e de código aberto, que oferece suporte aos padrões do Open Geoespatial Consortium (OGC) [2], além de ser extensível e interoperável com outras plataformas. O GeoNode possui uma estrutura de metadados baseada na ISO 19115 [3], essa aplicação Free Open Source Software (FOSS) GIS web tem sido uma ótima alternativa para implantar IDE e, por essa razão, tem sido muito adotada por empresas e instituições que possuem grande acervo de dados espaciais no Brasil e no mundo. Desta forma, visando trocar experiências sobre a aplicação FOSS GeoNode, profissionais de gestão de geoinformação da Embrapa, CPRM, ANA, IBGE e Geobases criaram um Grupo de Trabalho (GT) com reuniões periódicas a partir de 2020. Destas reuniões surgiu o interesse em criar uma comunidade brasileira de usuários GeoNode, e organizar um primeiro evento para disseminar, compartilhar e difundir conhecimentos sobre essa aplicação FOSS GIS, além de identificar outras iniciativas, em curso no país, que também estejam utilizando o GeoNode

    GeoNode-BR: comunidade brasileira para a colaboração entre usuários do software GeoNode.

    Get PDF
    O GeoNode é uma solução web para o gerenciamento de recursos espaciais [1], e para a implantação de Infraestruturas de Dados Espaciais (IDEs). É uma solução livre e de código aberto, que oferece suporte aos padrões do Open Geoespatial Consortium (OGC) [2], além de ser extensível e interoperável com outras plataformas. O GeoNode possui uma estrutura de metadados baseada na ISO 19115 [3], essa aplicação Free Open Source Software (FOSS) GIS web tem sido uma ótima alternativa para implantar IDE e, por essa razão, tem sido muito adotada por empresas e instituições que possuem grande acervo de dados espaciais no Brasil e no mundo. Desta forma, visando trocar experiências sobre a aplicação FOSS GeoNode, profissionais de gestão de geoinformação da Embrapa, CPRM, ANA, IBGE e Geobases criaram um Grupo de Trabalho (GT) com reuniões periódicas a partir de 2020. Destas reuniões surgiu o interesse em criar uma comunidade brasileira de usuários GeoNode, e organizar um primeiro evento para disseminar, compartilhar e difundir conhecimentos sobre essa aplicação FOSS GIS, além de identificar outras iniciativas, em curso no país, que também estejam utilizando o GeoNode
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