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Search Results: 1 - 10 of 3822 matches for " Vania Margaret Flosi Paschoalin "
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Biocatalytic production of chitosan polymers from shrimp shells, using a recombinant enzyme produced by pichia pastoris  [PDF]
Eduardo Mere Del Aguila, Laidson Paes Gomes, Cristina Trist?o Andrade, Joab Trajano Silva, Vania Margaret Flosi Paschoalin
American Journal of Molecular Biology (AJMB) , 2012, DOI: 10.4236/ajmb.2012.24035
Abstract: Chitosan has a unique chemical structure with high charge density, reactive hydroxyl and amino groups, and extensive hydrogen bonding. Chitin deacetylase (EC 3.5.1.41) catalyzes the hydrolysis of the N-acetamido groups of N-acetyl-D-glucosamine residues in chitin, converting it to chitosan and releasing acetate. The entire ORF of the CDA2 gene encoding one of the two isoforms of chitin deacetylase from Saccharomyces cerevisiae was cloned in Pichia pastoris. The Tg (Cda2-6xHis)p was expressed at high levels as a soluble intracellular protein after induction of the recombinant yeast culture with methanol, and purified using nickel-nitrilotriacetic acid chelate affinity chromatography, resulting in a protein preparation with a purity of >98% and an overall yield of 79%. Chitin deacetylase activity was measured by a colorimetric method based on the O-phthalaldehyde reagent, which detects primary amines remaining in chitinous substrate after acetate release. The recombinant enzyme could deacetylate chitin, chitobiose, chitotriose and chitotetraose, with an optimum temperature of 50°C and pH 8.0, determined using oligochitosaccharides as the substrates. The recombinant protein was also able to deacetylate its solid natural substrate, shrimp chitin, to a limited extent, producing chitosan with a degree of acetylation (DA) of 89% as determined by Fourier transform infrared spectroscopy. The degree of deacetylation was increased by pre-hydrolysis of crystalline shrimp chitin by chitinases, which increased the deacetylation ratio triggered by chitin deacetylase, producing chito-oligosaccharides with a degree of acetylation of 33%. The results described here open the possibility to use the rCda2p, combined with chitinases, for biocatalytic conversion of chitin to chitosan with controlled degrees of deacetylation. We show herein that the crystalline chitin form can be cleanly produced in virtually quantitative yield if a combined and sequential enzyme treatment is performed.
L-Arginine Supplementation and Nitric Oxide Production:No Additional Effect When Associated to Exercise  [PDF]
Diego dos Santos Bai?o, Carlos Adam Conte Jr., Joab Trajano Silva, Vania Margaret Flosi Paschoalin, Thiago Silveira Alvares
Food and Nutrition Sciences (FNS) , 2013, DOI: 10.4236/fns.2013.48101
Abstract:

L-arginine is an amino acid semiessencial considered a precursor of nitric oxide, a gas mainly produced in endothelial cells. Nutritional supplements based on the amino acid L-arginine have been broadly marketed in order to increase vasodilation and the blood supply to muscle in order to optimize metabolic responses induced by exercise. The main objective of this study was to evaluate the effect of L-arginine supplementation on nitric oxide production in response to exercise. Furthermore, the biochemical parameters of muscle fatigue were assessed. Fourteen trained runners were divided in two groups, supplemented with L-arginine (ARG) and placebo (PLA). Blood samples were collected before supplementation (T0), immediately after the first exercise session (T1), immediately after the second exercise session (T2), and after 20 minutes of rest (T3). Plasma cyclic guanosine monophosphate was assessed as a marker of nitric oxide production. The biochemical parameters of muscle fatigue analyzed were plasma lactate and ammonia. There was significant increase in plasma cyclic guanosine monophosphate in both groups in response to exercise: ARG (T0: 3.6 ± 1.4; T1: 17.9 ± 5.8; T2: 15.9 ± 5.3; T3: 7.3 ± 2.5 pmol/mL) and PLA (T0: 4.1 ± 1.1; T1: 18.8 ± 9.9; T2: 16.1 ± 3.5; T3: 9.3 ± 3.7 pmol/mL). A significant reduction in plasma lactate and ammonia were observed in the recovery period after exercise (T3). However, no significant difference was observed between groups in the variables studied. Therefore, L-arginine supplementation was unable to increase the effects of exercise on nitric oxide production and did not improve the metabolic responses to exercise in runners.

Acute L-Arginine supplementation does not increase nitric oxide production in healthy subjects
Thiago Silveira Alvares, Carlos Adam Conte-Junior, Joab Trajano Silva, Vania Margaret Flosi Paschoalin
Nutrition & Metabolism , 2012, DOI: 10.1186/1743-7075-9-54
Abstract:
Proteomic analysis of whey from bovine colostrum and mature milk
Golinelli, Luciana Pacheco;Conte-Junior, Carlos Adam;Paschoalin, Vania Margaret Flosi;Silva, Joab Trajano;
Brazilian Archives of Biology and Technology , 2011, DOI: 10.1590/S1516-89132011000400016
Abstract: the aim of this study was to standardize a methodology to obtain two-dimensional (2d) maps of whey proteins from bovine colostrum and mature milk, using two-dimensional electrophoresis, in order to identify the minor proteins by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (maldi tof/tof ms). a total of 38 proteins were identified, 20 spots in the colostrum whey and 18 in the mature milk whey; 5 of them were identified for the first time.
Quality of Semi-Prepared Products from Rainbow Trout Waste (Onchorynchus mykiss) by Using Different Technological Strategics  [PDF]
Karoline Ribeiro Palmeira, Eliane Teixeira Mársico, Laís Doro, M?sar Lemos, Claudia Emília Teixeira, Vania Margaret Flosi Paschoalin, Maria Lúcia Guerra Monteiro, Carlos Adam Conte Júnior
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.56067
Abstract:

The consumption of freshwater fish and fish products has gradually grown worldwide over the last decades, generating a proportional waste increase. The objective of the present study was to assess the chemical and bacteriological quality of restructured fish product, meatball-type, prepared with rainbow trout (Onchorynchus mykiss) waste added of 1% transglutaminase (MTG), 4% textured soy protein (TSP) and replacing part of the sodium chloride with potassium chloride (75%/25%) as described below: T1—starch addition (control); T2—MTG addition (1%); T3—soy protein addition (4%); T4—soy protein addition (4%) and MTG addition (1%); T5—soy protein addition (4%), MTG addition (1%) and partial replacement of salt (75% NaCl/25% KCl). Total aerobic mesophilic bacteria (TAMB), 2-thiobarbituric acid reactive substances (TBARS), pH determination and quantification of biogenic amines were performed on the day after manufacturing (P0) and after 60 days of storage (P1) at -25℃ ± 2℃. The results showed that there was no significant difference (p < 0.05) of microbiological quality, TBARS and pH after storage. T4 presented the lowest total biogenic amine content (256.84 mg/kg) whereas T3 and T5 had the highest value (791.36 and 707.19 mg/kg, respectively) in this parameter. Putrescine was the biogenic amine that presented the highest concentration (504.00 mg/kg) in T3 and cadaverine that presented the smallest concentration (0.36 mg/kg) in T4. The use of technological strategies for developing new products with non-commercial fillets kept the most standards, having changes only in some biogenic amines.

Qualitative and quantitative assessment of genetically modified soy in enteral nutrition formulas by polymerase chain reaction based methods
Barros, Natália Eudes Fagundes de;Oliveira, Edna Maria Morais;Silva, Otniel Freitas;Silva, Joab Trajano;Paschoalin, Vania Margaret Flosi;
Revista de Nutri??o , 2010, DOI: 10.1590/S1415-52732010000100006
Abstract: objective: the aim of this work was to investigate the occurrence of roundup ready soybean in enteral nutrition formulas sold in brazil. methods: a duplex polymerase chain reaction based on the amplification of the lectin gene and the construction of the recombinant deoxyribonucleic acid of transgenic glyphosate-tolerant soybean (35s promoter and chloroplast transit peptide gene) was performed in order to analyze the deoxyribonucleic acid obtained from nine soy protein isolate-containing formulas. results: despite the highly processed nature of the food matrices, amplifiable deoxyribonucleic acid templates were obtained from all tested samples, as judged by the amplification of the lectin gene sequence. however, amplicons relative to the presence of roundup ready soybean were restricted to one of the nine enteral nutrition formulas analyzed as well as to the soybean reference powder, as expected. quantitative analysis of the genetically modified formula by real-time polymerase chain reaction showed a content of approximately 0.3% (w/w) of recombinant deoxyribonucleic acid from the roundup ready soybean. conclusion: the results show that one of the formulas contained genetically modified soy, pointing to the need of regulating the use of transgenic substances and of specific labeling in this product category.
Detection of Mycobacterium bovis DNA in nasal swabs from tuberculous cattle by a multiplex PCR
Figueiredo, Eduardo Eustáquio de Souza;Carvalho, Ricardo Cezar Tavares;Silvestre, Flávia Galindo;Lilenbaum, Walter;Fonseca, Leila Sousa;Silva, Joab Trajano;Paschoalin, Vania Margaret Flosi;
Brazilian Journal of Microbiology , 2010, DOI: 10.1590/S1517-83822010000200020
Abstract: detection of tuberculosis in cattle relies on the intradermal tuberculin test (itt), but a definitive diagnosis requires identification of the pathogen after the animal is slaughtered. dna in nasal swabs from 50 cows was analyzed by m-pcr, targeting for the rvd1-rv2031c and is6110 sequences. m. bovis was identified in two of 34 tuberculous cows (5.9%). the use of mpcr of nasal swabs as an in vivo diagnostic tool for bovine tuberculosis is suggested.
Identification of Mycobacterium bovis Isolates by a multiplex PCR
Figueiredo, Eduardo Eustáquio de Souza;Silvestre, Flávia Galindo;Campos, Wilma Neres;Furlanetto, Leone Vinícius;Medeiros, Luciana;Lilenbaum, Walter;Fonseca, Leila Sousa;Silva, Joab Trajano;Paschoalin, Vania Margaret Flosi;
Brazilian Journal of Microbiology , 2009, DOI: 10.1590/S1517-83822009000200004
Abstract: isolates from suggestive bovine tuberculosis lesions were tested by a multiplex polymerase chain reaction (m-pcr) targeting for rvd1rv2031c and is6110 sequences, specific for m. bovis and mycobacterium tuberculosis complex respectively. the m-pcr successfully identified as m. bovis 88.24% of the isolates.
Purifica??o e caracteriza??o da quitinase de uva (Vitis vinífera L. cv Red Globe) para a produ??o de quitosana a partir de quitina de camar?o
Gomes, Laidson Paes;Oliveira, Carlos Ivan Ribeiro de;Silva, Márcia Cristina da;Andrade, Cristina Trist?o de;Del Aguila, Eduardo Mere;Silva, Joab Trajano;Paschoalin, Vania M. Flosi;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000900012
Abstract: chitinase is produced by a wide variety of plants as a defense against peste attacks. in this study, grape chitinases were purified 16 times by fractionation in 80% ammonium sulfate followed by dialysis and filtration. purified chitinases exhibited enzymatic activity toward chitin azure. the yield of purified chitinase was 229 mg/l with chitinase activity of 563 u/g. chitinases had molecular masses of 24 and 30 kda, as evaluated by sds-page 12.5%. two ph optima were determined 3.0 and 6.0. the optimal temperature was 42 °c. pre hydrolysis of crystalline shrimp chitin by chitinases caused in an increase in the deacetylation ratio triggered by chitin deacetylase producing chitooligosaccharides with da (degree acetylation) of 58.8%.
Polymorphic microsatellites of analysis in cultivars of taro
Nunes, Raquel SC;Pinhati, Fernanda R;Golinelli, Luciana P;Rebou?as, Tiyoko Nair H;Paschoalin, Vania Margaret F;Silva, Joab T da;
Horticultura Brasileira , 2012, DOI: 10.1590/S0102-05362012000100018
Abstract: taro (colocasia esculenta) is a tuberous plant belonging to the araceae family whose tuber is the 14th most consumed food crop in the world. characterized as an unconventional vegetable, taro is grown in brazil as a subsistence crop, but in recent years began to gain commercial importance, especially in the states of espirito santo, minas gerais and rio de janeiro. to avoid loss of genetic diversity of the local varieties traditionally grown in brazil a core collection for taro germplasm has been developed by the instituto capixaba de pesquisa, assistência técnica e extens?o rural do estado do espirito santo (incaper). the aim of this study was to perform a molecular characterization of the seven regional core collections. genetic diversity of the cultivars was investigated by using ssr (simple sequence repeats) polymorphisms, in seven loci (xuqtem55, xuqtem73, xuqtem84, xuqtem88, xuqtem91, xuqtem97 and xuqtem110). genetic diversity of the cultivars, based on the seven microsatellite alleles, was evaluated by using the software gelcompar ii, showed that the loci xuqtem73, xuqtem88 and xuqtem110 were the most informative, featuring 7, 10 and 8 alleles, respectively, a percentage of cultivars with polymorphic alleles of 85, 57 and 100% and identical pic of 0.91. based on xuqtem110 locus analysis, the seven cultivars were grouped in two clusters. chinês regional incaper cultivar was originated from chinês cultivar which originated the s?o bento cultivar, corroborating previous results. macaquinho and chinês cultivars were shown to be the primitive ones originating the allelic collections found in the states of mato grosso do sul and espirito santo.
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