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Search Results: 1 - 10 of 217578 matches for " André Luis Moreira de;Padilha "
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Texture analysis of cold rolled and annealed aluminum alloy produced by twin-roll casting
Martins, Juliana de Paula;Carvalho, André Luis Moreira de;Padilha, Angelo Fernando;
Materials Research , 2012, DOI: 10.1590/S1516-14392011005000101
Abstract: a 7.4 mm thick strip of 3003 aluminum alloy produced by the industrial twin-roll casting (trc) process was homogenized at 500 °c for 12 hours, after which it was cold rolled in two conditions: 1) to reduce the strip's thickness by 67%, and 2) to reduce it by 91%. the alloy was annealed at 400 °c for 1 hour in both conditions. the results revealed that a rotated cube texture, the {001}<110> component, predominated in the as-cast condition and was transformed into brass, copper and s type textures during the cold rolling process. there was practically no difference between the deformation textures at the two thickness reductions.
Determination of Metal Ions in Fuel Ethanol after Preconcentration on 5-Amino-1,3,4-Thiadiazole-2-Thiol Modified Silica Gel
Gomes, Luis A. de Melo;Padilha, Pedro de Magalh?es;Moreira, José Celso;Dias Filho, Newton L.;Gushikem, Yoshitaka;
Journal of the Brazilian Chemical Society , 1998, DOI: 10.1590/S0103-50531998000500015
Abstract: this work describes the synthesis and characterization of 5-amino-1,3,4-thiadiazole-2-thiol modified silica gel (siatt), and the results of a study of the adsorption and preconcentration (in batch, and in flow using a column technique) of cd(ii), co(ii), cu(ii), fe(iii), ni(ii), pb(ii) and zn(ii) in ethanol medium. the adsorption capacities for each metal ion were (in mmol g-1): cd(ii) = 0.11, co(ii) = 0.10, cu(ii) = 0.20, fe(iii) = 0.20, ni(ii) = 0.16, pb(ii) = 0.08 and zn(ii) = 0.12. the results obtained in the flow experiments, showed a recovery of ca. 100% of the metal ions adsorbed in a column packed with 2 g of siatt, using 5 ml of 2.0 mol l-1 hcl solution as eluent. the sorption-desorption of the metal ions made possible the development of a preconcentration method and quantification by flame aas of metal ions at trace level in fuel ethanol.
Determination of Metal Ions in Fuel Ethanol after Preconcentration on 5-Amino-1,3,4-Thiadiazole-2-Thiol Modified Silica Gel
Gomes Luis A. de Melo,Padilha Pedro de Magalh?es,Moreira José Celso,Dias Filho Newton L.
Journal of the Brazilian Chemical Society , 1998,
Abstract: This work describes the synthesis and characterization of 5-amino-1,3,4-thiadiazole-2-thiol modified silica gel (SiATT), and the results of a study of the adsorption and preconcentration (in batch, and in flow using a column technique) of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II) and Zn(II) in ethanol medium. The adsorption capacities for each metal ion were (in mmol g-1): Cd(II) = 0.11, Co(II) = 0.10, Cu(II) = 0.20, Fe(III) = 0.20, Ni(II) = 0.16, Pb(II) = 0.08 and Zn(II) = 0.12. The results obtained in the flow experiments, showed a recovery of ca. 100% of the metal ions adsorbed in a column packed with 2 g of SiATT, using 5 mL of 2.0 mol L-1 HCl solution as eluent. The sorption-desorption of the metal ions made possible the development of a preconcentration method and quantification by Flame AAS of metal ions at trace level in fuel ethanol.
Estenose da fossa intercondilar após estabiliza??o articular com retalho de fáscia lata em c?es
Selmi, André Luis;Padilha Filho, Jo?o Guilherme;Lins, Bruno Testoni;De Nardi, Andrigo Barboza;Penteado, Bianca Mota;
Ciência Rural , 2012, DOI: 10.1590/S0103-84782012000100019
Abstract: intercondylar fossa width indexes (ifwi) were determined in nine adult dogs submitted to intercondylar notchplasty (in) after transection of the cranial cruciate ligament (ccl) followed by a fascial strip stabilization. the right stifle was submitted to in followed by fascial strip reconstruction of the ccl (gi) while in the left stifle in was not performed (gc). each group was then divided into three subgroups which corresponded to time of euthanasia at 30, 90 and 180 days after surgery. ifwi were determined, both macroscopically and radiographically, by measuring the cranial outlet of the intercondylar fossa in relation to the epicondylar width. a significant increase was observed in indexes of gi following in, and these differed from indexes of gc throughout the evaluation period. it was concluded that articular repair using a fascia strip prevented stenosis of the intercondylar fossa, and that in caused a permanent widening of it.
Molecular characterization of clinical multiresistant isolates of Acinetobacter sp. from hospitals in Porto Alegre, State of Rio Grande do Sul, Brazil
Ferreira, Alessandra Einsfeld;Marchetti, Desirée Padilha;Cunha, Gabriela Rosa da;Oliveira, Lyvia Moreira de;Fuentefria, Daiane Bopp;Bello, Aline Gehlen Dall;Barth, Afonso Luis;Cor??o, Gertrudes;
Revista da Sociedade Brasileira de Medicina Tropical , 2011, DOI: 10.1590/S0037-86822011000600014
Abstract: introduction: hospitals around the world have presented multiresistant acinetobacter sp. outbreaks. the spread of these isolates that harbor an increasing variety of resistance genes makes the treatment of these infections and their control within the hospital environment more difficult. this study aimed to evaluate the occurrence and dissemination of acinetobacter sp. multiresistant isolates and to identify acquired resistance genes. methods: we analyzed 274 clinical isolates of acinetobacter sp. from five hospitals in porto alegre, rs, brazil. we evaluated the susceptibility to antimicrobial, acquired resistance genes from ambler's classes b and d, and performed molecular typing of the isolates using enterobacterial repetitive intergenic consensus-polymerase chain reaction (eric-pcr) technique. results: a high (68%) percentage of multiresistant isolates of acinetobacter sp. was observed, and 69% were resistant to carbapenems. we identified 84% of isolates belonging to species a. baumannii because they presented the gene blaoxa-51. the gene blaoxa-23 was detected in 62% of the isolates, and among these, 98% were resistant to carbapenems. using the eric-pcr technique, we identified clones of acinetobacter sp. spread among the four hospitals analyzed during the sampling period. conclusions: the data indicate the dissemination of acinetobacter sp. isolates among hospitals and their permanence in the hospital after one year.
Isolation and partial characterization of a lectin from Bauhinia pentandra (bong) vog. Ex. Steua.
SILVA, ANDRé LUIS COELHO DA;HORTA, ANA CECíLIA GóES;MOREIRA, RENATO DE AZEVEDO;
Revista Brasileira de Fisiologia Vegetal , 2001, DOI: 10.1590/S0103-31312001000300002
Abstract: bauhinia pentandra (bong) vog. ex. steua seeds were investigated with respect to phenologic aspects (size, mass, hilum and length) and with respect to their chemical composition. the total nitrogen content of the seed flour was determined, and the flour was extracted in different ph values. a lectin was isolated from the seeds by sepharose-4b affinity chromatography. the homogeneity of the lectin was demonstrated by sds-page in the presence of b-mercaptoethanol. only one protein band with an apparent molecular mass of 30 kda was found. the b. pentandra lectin showed a carbohydrate specificity for d-galactose, a requirement for divalent metal cations (ca2+ and mn2+) for full activity and amino acid composition with a high content of aspartic acid, glutamic acid and alanine and low levels of methionine, cysteine and tryptophan. the lectin agglutinated rabbit and human a group erythrocytes and was relatively stable to heat treatment, retaining half of its original activity after 60 min at 70 oc.
Isolation and partial characterization of a lectin from Bauhinia pentandra (bong) vog. Ex. Steua.
SILVA ANDRé LUIS COELHO DA,HORTA ANA CECíLIA GóES,MOREIRA RENATO DE AZEVEDO
Revista Brasileira de Fisiologia Vegetal , 2001,
Abstract: Bauhinia pentandra (Bong) Vog. ex. Steua seeds were investigated with respect to phenologic aspects (size, mass, hilum and length) and with respect to their chemical composition. The total nitrogen content of the seed flour was determined, and the flour was extracted in different pH values. A lectin was isolated from the seeds by Sepharose-4B affinity chromatography. The homogeneity of the lectin was demonstrated by SDS-PAGE in the presence of beta-mercaptoethanol. Only one protein band with an apparent molecular mass of 30 kDa was found. The B. pentandra lectin showed a carbohydrate specificity for D-galactose, a requirement for divalent metal cations (Ca2+ and Mn2+) for full activity and amino acid composition with a high content of aspartic acid, glutamic acid and alanine and low levels of methionine, cysteine and tryptophan. The lectin agglutinated rabbit and human A group erythrocytes and was relatively stable to heat treatment, retaining half of its original activity after 60 min at 70 oC.
Lipase Activity among Bacteria Isolated from Amazonian Soils
André Luis Willerding,Luiz Antonio de Oliveira,Francisco Wesen Moreira,Mariana Gomes Germano,Aloísio Freitas Chagas Jr.
Enzyme Research , 2011, DOI: 10.4061/2011/720194
Abstract: The objective of this study was to select lipase-producing bacteria collected from different counties of the Amazon region. Of the 440 bacteria strains, 181 were selected for the lipase assay in qualitative tests at Petri dishes, being 75 (41%) lipase positive. The enzymatic index was determined during fifteen days at different temperatures (30°, 35°, 40°, and 45°C). The highest lipase activity was observed within 72 hours at 30°C. Twelve bacteria strains presented an index equal to or greater than the standard used like reference, demonstrating the potential of microbial resource. After the bioassay in Petri dishes, the selected bacteria strains were analyzed in quantitative tests on p-nitrophenyl palmitate (p-NPP). A group of the strains was selected for other phases of study with the use in oleaginous substrates of the Amazonian flora, aiming for the application in processes like oil biotransformation. 1. Introduction Lipase (triacylglycerol acylhydrolase E.C. 3.1.1.3) has an extensive industrial application by hydrolysing acyl ester bonds from acylglycerols at the interface between oil and water, acting also in the esterification and transesterification reactions [1–3]. Lipases are produced by many microorganisms. Most commercially useful lipases are of microbial origin. The increasing tendency of its market shows the importance to search new microbial resources to produce these enzymes [4, 5]. Lipase-producing microorganisms have been found in different habitats such as industrial wastes, vegetable oil processing factories, dairies, soil contaminated with oil, oilseeds, and decaying food [6]. Lipase from different microorganisms presents different chemical characteristics, which may be useful for industries. A specific lipase activity of P. fluorescens S1K W1 was found in a medium which contained emulsified olive oil as carbon source. The enzyme showed a high lipolytic activity towards tricaproic (C6) and tricaprylin (C8) compared to the other triacylglycerols examined; also, it preferentially hydrolyzed the ester bonds in 1 and 3 of triolein [7]. Temperature and pH activity also may be different among lipases [8]. The environmental conditions of Amazon favor high metabolic activities and growth of several microorganisms. This microbial diversity may be useful to find new good enzymatic resources. The aim of this study was to evaluate the production of lipase from the collection of soil microorganisms from the National Institute for Amazon Research (INPA), aiming for the application in processes like oil biotransformation. 2. Materials and Methods
In vitro induction of callus from cotyledon and hypocotyl explants of Glycine wightii (Wight & Arn.) Verdc.
Silva, André Luis Coelho da;Caruso, Cecília Sulzbacher;Moreira, Renato de Azevedo;Horta, Ana Cecília Góes;
Ciência e Agrotecnologia , 2003, DOI: 10.1590/S1413-70542003000600011
Abstract: with the objective to promote in vitro callus induction, cotyledon and hypocotyl segments of "perennial soybean" (glycine wightii (wight & arn.) verdc.) were inoculated in basal medium ms supplemented with sucrose (1.5 e 3%) and 0.8% agar and different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) and 6-furfurylaminopurine (kinetin). the explants were maintained in a dark growth room at 28oc. the best callus induction was observed in explants (cotyledon and hypocotyl) maintained in medium containing the combination of 2,4-d (1 mg.l-1), kinetin (0.1 mg.l-1) and 3% sucrose. to promote callus subculture, the ms medium was supplemented with different combinations of 2,4-d (0.5 to 4.0 mg.l-1), with or without kinetin (0.1 mg.l-1) and sucrose (1.5 e 3%). the calli were maintained 35 days in a dark growth room at 28oc. the results indicated that the use of 2,4-d 1.0 mg.l-1 + kinetin 0.1 mg.l-1 + sucrose 3% provided the highest average weight of cotyledons calli fresh matter, whereas the use of 2,4-d 2.0 mg.l-1 + kinetin 0.1 mg.l-1 + sucrose 3% provided the highest average weight of hypocotyl calli fresh matter. high concentrations of 2,4-d, independent of kinetin and sucrose concentrations, promoted oxidation and reduction in fresh weight from calli of cotyledon and hypocotyls.
Growth characteristics and dynamics of protein synthesis in callus cultures from Glycine wightii (Wight & Arn.) Verdc.
Silva, André Luis Coelho da;Caruso, Cecília Sulzbacher;Moreira, Renato de Azevedo;Horta, Ana Cecília Góes;
Ciência e Agrotecnologia , 2005, DOI: 10.1590/S1413-70542005000600009
Abstract: cotyledon explants were first cultured on ms medium supplemented with 4.52 m 2,4-d and 0.46 mm kinetin. the development of the calli was followed (0, 4, 8, 12, 16, 20, 24, 28 and 32 days after) and the growth curve was determined, based in fresh and dry weight. the growth curve presented sigmoidal form with four distinct phases. the highest growth percentage was observed at the exponential phase and the lowest at the stationary phase. these results indicated that cotyledon callus subculture should be performed 20 days after inoculation. the calli obtained after a period of 28 days were freeze dried, macerated and submitted to extraction with buffers of different ph values (2.6; 4.0; 6.0; 8.0 and 10.0) and the proteins in the extracts were determined by bradford method. the ph 8.0 buffer was the most efficient to extract the largest amount of protein. the amino acid analyses calli showed a high content of aspartic acid and low content of metionin. the dynamics of protein synthesis in calli was followed by sds-page electrophoresis.
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