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Search Results: 1 - 10 of 65639 matches for " Jorge Luiz Cavalcante;Araújo "
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Partial purification and characterization of xylanase produced by Penicillium expansum
Querido, André Luiz de Souza;Coelho, Jorge Luiz Cavalcante;Araújo, Elza Fernandes de;Chaves-Alves, Virgínia Maria;
Brazilian Archives of Biology and Technology , 2006, DOI: 10.1590/S1516-89132006000400016
Abstract: an extracellular xylanase was found to be the major protein in the filtrate culture of penicillium expansum when grown on 0.3 % wheat bran, which showed no xylanase multiplicity. the enzime was partial purified by.ammonium sulfate fractioning, molecular exclusion chromatography, ultrafiltration and anion exchange chromatography. the protein eluation profile showed only one form of xylanase that was partially characterized. the activity of purified xylanase was optimal at ph 5.5 and 40 oc. the enzyme was stable at ph between 5.5 and 6.5 and temperatures between 20-40 oc. the enzyme showed a km of 3.03 mm and vmax of 0.027 mmol min-1 mg -1 of protein. the enzymatic activity was increased 31 % by mg2+ and 28 % by al3+.
A distribui??o dos eosinófilos nas diferentes fases de evolu??o do granuloma hepático em camundongos infectados pelo Schistosoma mansoni
Lins, Romero Antunes Barreto;Cavalcanti, Carmelita Bezerra de Lima;Araújo-Filho, Jorge Luiz Silva;Melo-Júnior, Mário Ribeiro de;Chaves, Maria Elizabeth Cavalcante;
Revista da Sociedade Brasileira de Medicina Tropical , 2008, DOI: 10.1590/S0037-86822008000200008
Abstract: in the present study, the distribution of eosinophils at different stages of the formation of hepatic granuloma in mice infected with schistosoma mansoni was evaluated. from the results obtained, we suggest a new classification for the evolution of hepatic granuloma in mice, constructed from the phases described by other authors. in each phase, there is a different pattern of eosinophil distribution. in the exudative-necrotic phase, the eosinophils are concentrated in the periphery and center of the granuloma, and are scarce in the necrotic area; in the productive phase, the eosinophils are dispersed throughout the granuloma; and in the cure due to fibrosis phase, the eosinophils are concentrated in the periphery and center of the granuloma. eosinophils were found in direct contact with the eggs at all stages of evolution of the granuloma. it was concluded that the dynamics of eosinophils have an important role in forming the granulomatous reaction of the host and in resolving the inflammatory process caused by the parasite egg, as well as adding new data regarding hepatic granuloma classification.
Impacts of the Brazilian science and technology sectoral funds on the industrial firms’ R&D inputs and outputs Impactos dos fundos setoriais nas empresas
Bruno César Araújo,Donald Pianto,Fernanda De Negri,Luiz Ricardo Cavalcante
Revista Brasileira de Inova??o , 2012,
Abstract: The Brazilian science and technology sectoral funds were established at the end of the 1990s, aiming at providing more stable financial resources to science, technology, and innovation (ST&I) activities in the country. Similarly to other instruments used to foster innovation at the firm level, the sectoral funds are expected to increase firms’ technological efforts as well as their result indicators. The aim of this paper is to evaluate the impacts of these funds on the industrial firms’ R&D inputs and outputs in Brazil during the period between 2001 and 2006. Several papers have discussed the additionality or crowding out effects of innovation policies that involve grants and fiscal incentives, for example. In this paper, the firms which accessed the sectoral funds are compared with the ones which did not, based upon the path followed by their indicators of technological efforts (R&D inputs) and results (R&D outputs). The control group was defined using a Propensity Score Matching (PSM) procedure aiming at reducing the selection bias that makes firms which accessed the funds follow a different path when compared to the ones that did not. Percentage difference-in-differences indicate a significant detachment between the technological efforts of the treatment and control groups and permit the hypothesis of crowding out to be rejected. The growth differential on the PoTec variable – the proxy for technological efforts – is estimated in 6.8 p.p. in the first year, 11.5 in the second, 15.7 p.p. in the third and 26.7 p.p. in the fourth year after the access to the funds. The sectoral funds also presented a significant and positive impact on the number of employees, although only a marginally significant impact on high-tech exports was observed four years after the treatment. Additionally, a preliminary analysis of the impacts of the different instruments that form the sectoral funds suggests that most impacts observed in the technological efforts can be associated to the credit at favorable conditions. Resumo >Os fundos setoriais foram instituídos no final da década de 1990, com o propósito de criar condi es mais estáveis de financiamento público às atividades de ciência, tecnologia e inova o (CT&I) no Brasil. De maneira análoga ao que se observa com outros instrumentos de incentivo à inova o nas empresas, a expectativa é que o acesso aos fundos setoriais contribuiria para o aumento dos esfor os tecnológicos e para o alcance de melhores resultados pelas empresas. O objetivo deste trabalho é, portanto, avaliar o impacto desses fundos sobre os esfor os tecno
Paula Letícia Nemes Schawb Gomes,Leandro Cavalcante Lipinski,Raimundo Jorge Teles de Araújo Pereira
Ciência Animal Brasileira , 2009,
Caracteriza??o da microestrutura de caulinitas pela difra??o de raios x
Araújo, Jorge Corrêa de;Assis, Joaquim Teixeira de;Monine, Vladimir Ivanovitch;Bertolino, Luiz Carlos;
Matéria (Rio de Janeiro) , 2006, DOI: 10.1590/S1517-70762006000300026
Abstract: in this work, the modified thompson-cox-hastings function (tchz) was used in the analisys of the integral breadths obtained from the broadned x ray diffraction line profiles. these set of x ray diffraction results were calculated from the "le bail" fitting method, which does not require any structural information, except unit cell and resolution instrumental parameters. the refinement used here is called ?profile matching' in the fullprof, a program for rietveld analysis. the method was applied in two case size-strain broadening of kaolinites from brazilian deposits that after the treatment chemical and physical still had a content ranging between 1,55 % w/w (intermediate) to amount of 3,04% w/w (high) of structural and total iron. the rietveld refinement was first performed by using the set of data from standard reference material lab6to obtain all the instrumental parameters, simultaneously. this result has been used as an independent method to validate the results obtained by the ?profile matching' method. it has been shown that the crystallite size decreasing and the strain increasing with fe2o3 (% w/w) contents. the lorentzian shape of the inherent widths of the lines diffraction is a strong indication that are the small crystallite size the main cause of the analysed kaolinites samples.
Quantifica??o de nitrato e nitrito em lingüi?as do tipo frescal
Oliveira, Milyan Jorge de;Araújo, Wilma M. C.;Borgo, Luiz Ant?nio;
Ciência e Tecnologia de Alimentos , 2005, DOI: 10.1590/S0101-20612005000400018
Abstract: the objective of this study was to quantify the nitrate and the nitrite level of four distinctive lots of pork leg and chicken sausages of seven different producers. the experimental outline was at random with a factorial treatment of 7x4. to the obtained data, a variance analysis was applied in order to reach the medium square of the residue. in order to verify homogeneity of the experiments, the hartley test was used. it was followed by the joint analysis to compare the two types of sausages. the factorial schema of 7x4x2 was applied to obtain the significant f. the tukey test was also conducted with a 1% significance level. the results indicated that the samples of chicken fresh sausages showed levels between 7.6 to 312.5 ppm for the sodium nitrate fraction and levels between 1.2 to 221 ppm for the nitrite fraction. for the samples of pork leg fresh sausages, the obtained values were between 8.6 to 363.6 ppm for nitrate and between 0.6 to 162.2 ppm for nitrite. among the chicken sausage lots, the variation ranged from 7.6 to 312.5 ppm for the nitrate fraction and from 1.2 to 221 ppm for the nitrite. the pork leg sausage samples showed values from 100 to 104,3 ppm for nitrate and from 0.6 to 162.2 for nitrite. 7.1% of the samples were in discordance to the legislation.
Determina??o dos parametros microestruturais de amostras de caulinitas usando o método de refinamento do perfil de difra??o de raios X
Araújo, Jorge Corrêa de;Assis, Joaquim Teixeira de;Monin, Vladimir Ivanovitch;Bertolino, Luiz Carlos;
Rem: Revista Escola de Minas , 2005, DOI: 10.1590/S0370-44672005000400003
Abstract: from the x-ray diffraction theory, we know that the broadening of the reflection lines obtained from a powder sample may be related to some imperfection of the crystallite. such broadening effect may also be caused by instrumental failures and dispersion of the length of the radiation. in this study, the micro structural parameters of two improved samples of kaolinites were obtained through the method of fitting profiles. this method is also known as le bail fitting method and was embodied in the version of fullprof, a program of rietveld analysis. the rietveld refinement was performed with the data obtained from the standard reference material lab6. this refinement led to a set of instrumental function parameters and the validation method of the results obtained by the profile matching method. a modified pseudo-voigt function (tchz) was used to fit the profiles. the integral broadening and the parameters, bh and hh, respectively, were calculated from the program and used as data base for the tchzpv "model". the results of the microstructural parameters computed by both methods match well, suggesting that the size of the crystallites is the major cause of the kaolinite crystalline imperfections.
Risco e competi??o bancária no Brasil
Araújo, Luiz Alberto D'ávila de;Jorge Neto, Paulo de Melo;
Revista Brasileira de Economia , 2007, DOI: 10.1590/S0034-71402007000200003
Abstract: one of the most relevant discussions on bank regulation is the dichotomy between liberalization, with higher competition, and financial stability. to investigate this problem, the article examines competitive conditions and risk taking in brazilian banks, and investigates their relationship. competition is measured using panzar & rosse model and risk taking by basel brazilian index. given the relevance of the discussion, we use the concentration index as a measure of market structure. it is shown that brazilian banks operate in monopolist competition and that competition increases risk taking.
Estudo experimental da influência da altura do enxerto ósseo intersomático na estabilidade da fixa??o monossegmentar anterior da coluna cervical
Léo, Jorge Alfredo;Shimano, Antonio Carlos;Pereira, Gilberto de Araújo;Defino, Helton Luiz Aparecido;
Revista Brasileira de Ortopedia , 2008, DOI: 10.1590/S0102-36162008000600005
Abstract: objective: to perform an experimental study of the impact of intersomatic bone graft height of the cervical spine on the mechanical stability of anterior cervical fixation. methods: mechanical assays were performed using swine cervical spine (c3-c4). three experimental groups were formed with 20 cervical spine segments (c3-c4) according to the degree of stability achieved and the fixation of the vertebral segment. group i: removal of the intervertebral disc and placement of intersomatic graft. group ii: removal of the intervertebral disc, placement of the intersomatic graft, and anterior fixation with plate. group iii: removal of the intervertebral disc, bilateral section of posterior ligaments and joint capsules, placement of intersomatic graft, and anterior fixation with plate. each experimental group was divided into two subgroups, according to the height of the bone graft used (3.0 mm or 6.0 mm). vertebral segments were submitted to mechanical assays of flexion, lateral flexion, and torsion in a universal assay machine. the parameters analyzed were maximum strength (n) and the time (nm) to produce a predetermined deflection. results: considering all experimental groups, the authors did not observe a statistical difference among the maximum strength (n) and time (nm) between the different heights (3.0 mm and 6.0 mm) of the intersomatic bone graft. conclusions: immediate mechanical stability of anterior monosegmental cervical arthrodesis was not impacted by the intersomatic graft height in the flexion, lateral flexion, and torsion assays.
Tamanho de amostras para avalia??o da severidade da queima das folhas do inhame
Michereff, Sami Jorge;Noronha, Mariss?nia de Araújo;Maffia, Luiz Antonio;
Summa Phytopathologica , 2008, DOI: 10.1590/S0100-54052008000200018
Abstract: leaf blight, caused by curvularia eragrostidis, is the major foliar disease of yam in the brazilian northeast. optimum sample size were determined in 15 commercial yam (cv. da costa) areas, located at zona da mata, pernambuco state, northeast of brazil, aiming to orientate the disease assessment of yam leaf blight in field conditions. disease severity was assessed in 100 plants by field in extracts of 5, 15, and 30 leaves by plant. the data set from each area were analyzed by a method that specified the level of acceptable error, determined by the mean coefficient of variation. the disease severity ranged between 0.41 and 22.34% and was negatively correlated (p=0.05) with the sample size. the increase of 15 to 30 leaves sampled for plant result small reduction in the total number of plants to be sampled differing of the observed when the increase was from 5 to 15 leaves. based on data set and considering 10% of acceptable error, future surveys of yam leaf blight severity in northeast fields should analyze 37 plants/ha and 15 leaves/plant.
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