570 research outputs found
O tipo de modelação dos pneus dos veículos pesados na avaliação do desempenho dos pavimentos
Os veículos pesados são os principais responsáveis pela degradação dos pavimentos rodoviários provocando
principalmente fendilhamento por fadiga e deformações permanentes. Os pavimentos rodoviários são dimensionados para
suportar o tráfego de projecto, o qual é composto por diferentes tipos de veículos com diferentes tipos de eixos e rodas,
sendo a carga total do veículo função de vários factores. Alguns destes veículos pesados causam maiores degradações nos
pavimentos devido ao tipo de suspensão, tipo de pneu, localização dos eixos ou pressão de enchimento dos pneus. No
entanto, em termos de dimensionamento, esta diversidade de veículos é considerada de modo semelhante pela atribuição de
uma área onde é aplicada a carga dos veículos, verificando-se que a configuração desta área não representa correctamente o
contacto dos pneus com o pavimento.
Deste modo, este trabalho pretende estudar a acção dos veículos pesados na avaliação do comportamento do pavimento
considerando a carga dos veículos pesados modelada de forma mais aproximada da real, nomeadamente, considerando os
sulcos dos pneus e a variação não uniforme da pressão de contacto pneu-pavimento. Assim, neste trabalho é modelado um
pavimento representativo da rede rodoviária no qual são aplicadas diferentes configurações de carga sendo obtido o estado
de tensão/deformação instalado no pavimento. A modelação numérica do pavimento foi realizada utilizando um modelo
elástico linear de elementos finitos em três dimensões desenvolvido para analisar a influência de um veículo pesado
possuindo uma configuração de pneus duplos com 245mm de largura. Neste estudo foram consideradas duas configurações
de distribuição de pressões de contacto, em que foram considerados as seguintes pressões totais: 700, 800, 900, 1200 e
1500 kPa. Com base nos resultados obtidos é possível observar as diferenças significativas no estado de tensão/deformação
do pavimento, principalmente à superfície a qual poderá ser responsável pelo fendilhamento com origem à superfície.Road pavements have been designed to support the design traffic which is composed by different type of vehicles with
different axle configurations, load magnitudes, wheel types and tire inflation pressures. Traffic loads are the major source
of pavement damage by causing fatigue, which leads to cracking and permanent deformation. Heavy vehicles do not cause
equal damage because the differences in wheel loads, number and location of axles, types of suspensions and tires.
Furthermore, the damage is specific to the pavement properties, operating conditions and environmental factors. This
research proposes a model for predicting the mechanical behaviour of flexible pavement subjected to heavy load vehicle
with dual-tire configuration using a numerical simulation. An elastic finite element model in three dimensions (3D) was
developed to analyze the influence of a heavy vehicle with dual-tire configuration featuring 245 mm wide on each tire. This
research studied three configurations of contact pressure considering the following pressures: 700, 800, 900, 1200 and 1500
kPa. The results show that it is possible to observe significant differences in the state of stress/strain on the pavement,
especially on the surface which is responsible for cracking originating at the surface. The simulation model present here
will be useful for future pavement design and material selection
Essential role of the czc determinant for cadmium, cobalt and zinc resistance in Gluconacetobacter diazotrophicus PAl 5
The mechanisms of cadmium, cobalt and zinc resistance were characterized in the plant-growth-promoting bacterium Gluconacetobacter diazotrophicus PAl 5. The resistance level of the wild-type strain was evaluated through the establishment of minimum inhibitory concentrations (MIC) of the soluble compounds CdCl2·H2O, CoCl2·6H2O and ZnCl2. Gluconacetobacter diazotrophicus PAl 5 was resistant to high concentrations of Cd, Co and Zn, with MICs of 1.2, 20 and 20 mM, respectively. Screening of an insertion library from transposon EZ-Tn5<R6Kyori/KAN-2> in the presence of ZnO revealed that the mutant GDP30H3 was unable to grow in the presence of the compound. This mutant was also highly sensitive to CdCl2·H2O, CoCl2·6H2O and ZnCl2. Molecular characterization established that the mutation affected the czcA gene, which encodes a protein involved in metal efflux. In silico analysis showed that czcA is a component of the czcCBARS operon together with four other genes. This work provides evidence of the high tolerance of G. diazotrophicus PAl 5 to heavy metalsand that czc is a determinant for metal resistance in this bacterium. [Int Microbiol 2012; 15(2):69-78
Crystal structure and biochemical characterization of the recombinant ThBgl, a GH1 β-glucosidase overexpressed in Trichoderma harzianum under biomass degradation conditions
Additional file 3: Table S3. Percent identity matrix between the GH3 β-glucosidase. The multiple sequence alignment was performed using the Clustal Omega server ( http://www.ebi.ac.uk/Tools/msa/clustalo/ )
Influence of different restraint protocols for the electrocardiogram values of feline night monkeys (Aotus azarae infulatus
Universidade do Estado do Pará. Centro de Ciências Biológicas
e da Saúde. Laboratório de Cirurgia Experimental. Belém, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Centro Nacional de Primatas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Centro Nacional de Primatas. Ananindeua, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brasil.Universidade do Estado do Pará. Centro de Ciências Biológicas
e da Saúde. Laboratório de Cirurgia Experimental. Belém, PA, Brasil.Macacos-da-noite são muito susceptíveis ao estresse e por isso a contenção química ou física deve ser cuidadosamente avaliada antes de qualquer procedimento. Protocolos anestésicos podem alterar alguns parâmetros fisiológicos, sendo o eletrocardiograma (ECG) um exame muito utilizado para avaliação do ritmo e da frequência cardíaca. O objetivo deste estudo foi avaliar a influência de quatro diferentes protocolos de contenção sobre o ECG realizado em Aotus azarae infulatus. Para isso foram utilizados 10 animais, machos, adultos, submetidos à contenção com a associação tiletamina/zolazepam (TZ), isoflurano (ISO), associação cetamina e midazolam (CET) e contenção física (CF). Não foram observadas diferenças nos parâmetros de ondas e complexos obtidos no ECG em todos os grupos testados, no entanto, durante a avaliação do traçado os animais do grupo CF apresentaram uma quantidade maior de alterações. Concluiu-se que os protocolos de contenção utilizados não alteraram os valores do ECG e que não foi possível considerar o grupo CF como controle devido causar mais alterações do que todos os protocolos testados
Worsening of pain and swelling following triamcinolone hexacetonide intra-articular injection: a prospective study in a cohort of patients with rheumatic diseases
Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
In Vitro
Jaboticaba is a fruit from a native tree to Brazil, Plinia peruviana. Jaboticaba peels are an important source of antioxidant molecules such as phenolic compounds. This study aimed to evaluate in vitro the activity of a hydroalcoholic extract of jaboticaba fruit peels (HEJFP) in wound healing processes and antioxidant activity in murine fibroblasts (L929 cell line). HEJFP concentrations (0.5, 1, 5, 10, 25, 50, 100, and 200 µg/mL) were tested in MTT assay and cell proliferation was verified at 100 µg/mL after 24 h and at 25, 50, and 100 µg/mL after 48 h of extract exposure. Evaluation of antioxidant activity was performed at 0.5, 5, 25, 50, and 100 µg/mL HEJFP concentrations. Cell treatment with HEJFP at 25, 50, and 100 µg/mL for 24 h followed by H2O2 exposure for 3 h showed a strong cytoprotective effect. In vitro scratch wound healing assay indicated that none of tested HEJFP concentrations (0.5, 5, 25, 50, and 100 µg/mL) were capable of increasing migration rate after 12 h of incubation. These results demonstrate a positive effect of HEJFP on the wound healing process on L929 fibroblasts cell line, probably due to the antioxidant activity exhibited by phytochemicals in the extract
UV-visible scanning spectrophotometry and chemometric analysis as tools for carotenoids analysis in cassava genotypes (Manihot esculenta Crantz)
In this study, the metabolomics characterization focusing on the carotenoid composition of ten cassava (Manihot esculenta) genotypes cultivated in southern Brazil by UV-visible scanning spectrophotometry and reverse phase-high performance liquid chromatography was performed. Cassava roots rich in -carotene are an important staple food for populations with risk of vitamin A deficiency. Cassava genotypes with high pro-vitamin A activity have been identified as a strategy to reduce the prevalence of deficiency of this vitamin. The data set was used for the construction of a descriptive model by chemometric analysis. The genotypes of yellow-fleshed roots were clustered by the higher concentrations of cis--carotene and lutein. Inversely, cream-fleshed roots genotypes were grouped precisely due to their lower concentrations of these pigments, as samples rich in lycopene (redfleshed) differed among the studied genotypes. The analytical approach (UV-Vis, HPLC, and chemometrics) used showed to be efficient for understanding the chemodiversity of cassava genotypes, allowing to classify them according to important features for human health and nutrition.FAPESC (Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina) and
CNPq (Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico) for financial support.
The research fellowship from CNPq on behalf of the last author is acknowledged. The work is
partially funded by Project PropMine, funded by the agreement between Portuguese FCT and
Brazilian CNPq. The authors also thank the FCT Strategic Project of UID/BIO/04469/2013
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Identifying COPD patients at risk for worse symptoms, HRQoL, and self-efficacy: A cluster analysis
Homozygous Inactivating Mutation In Nanos3 In Two Sisters With Primary Ovarian Insufficiency.
Despite the increasing understanding of female reproduction, the molecular diagnosis of primary ovarian insufficiency (POI) is seldom obtained. The RNA-binding protein NANOS3 poses as an interesting candidate gene for POI since members of the Nanos family have an evolutionarily conserved function in germ cell development and maintenance by repressing apoptosis. We performed mutational analysis of NANOS3 in a cohort of 85 Brazilian women with familial or isolated POI, presenting with primary or secondary amenorrhea, and in ethnically-matched control women. A homozygous p.Glu120Lys mutation in NANOS3 was identified in two sisters with primary amenorrhea. The substituted amino acid is located within the second C2HC motif in the conserved zinc finger domain of NANOS3 and in silico molecular modelling suggests destabilization of protein-RNA interaction. In vitro analyses of apoptosis through flow cytometry and confocal microscopy show that NANOS3 capacity to prevent apoptosis was impaired by this mutation. The identification of an inactivating missense mutation in NANOS3 suggests a mechanism for POI involving increased primordial germ cells (PGCs) apoptosis during embryonic cell migration and highlights the importance of NANOS proteins in human ovarian biology.201478746
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