975 resultados para pH and acidity
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The aim of this study was to evaluate the effect of gamma irradiation associated with modified atmosphere in cold storage of guava ‘Pedro Sato’ minimally processed, checking their physical-chemical characteristics. Were used guavas from the region of Vista Alegre do Alto/São Paulo/Brazil. After harvest, fruits were immediately transported to the Fruit and Vegetables Laboratory from the Agroindustrial Management and Technology Department, Agronomic Sciences College - UNESP - Botucatu / SP, where they were kept at 10 ° C and 90-95% RH in cold storage, for 12 days. In the laboratory, fruits were selected by size and lack of defects in order to standardize the lot and then were cut into slices 0.5 cm thick. We used the completely randomized design, with factorial design 5 x 5, with three replications. The first factor consisted of the following effects: control 1 (without package or irradiation), control 2 (polystyrene package/PS + package low density polyethylene/LDPE and without irradiation), treatment 1 (PS + LDPE and 0.2 kGy ), treatment 2 (PS + LDPE and 0.6 kGy) and treatment 3 (PS + LDPE and 1.0 kGy). The second factor consisted of the evaluation periods: 0, 3, 6, 9 and 12 days. The analyses were: firmness, soluble solids (SS), titratable acidity (TA), maturity index, pH, breathing behavior. In the end of this work it was concluded that the lower dose of radiation associated with modified atmosphere promoted positive effect on physical-chemical characteristics of guava ‘Pedro Sato’, providing fruits with higher quality and durability, due to higher maintenance of pulp firmness, the highest pH and soluble solids obtained. Regarding the storage days, there were no beneficial effect of the treatments during storage, mainly due to the sensitivity of fruits submitted to gamma irradiation, where only the early days provided better values for the variables.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Microbiologia Agropecuária - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Proteção de Plantas) - FCA
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Pós-graduação em Agronomia (Horticultura) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Proteção de Plantas) - FCA
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Pós-graduação em Agronomia (Horticultura) - FCA
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The results of video-assisted thoracic sympathectomy (VATS)in children are unknown. To investigate the improvement in quality of life (QOL) of a group of 45 children who did and did not undergo VATS for the treatment of palmar hyperhidrosis (PH) 4 years after the initial evaluation. Forty-five children with PH were initially evaluated. Children were divided into two groups: 30 in the VATS group and 15 in the control group. We studied the evolution of PH, negative effect of hyperhidrosis on the QOL before the treatment, and improvement in QOL after treatment. Twenty-five patients (83.4%) in the VATS group experienced great improvement in PH, and five (16.6%) experienced partial improvement; 12 (80.0%) children from the control group had some type of improvement, and three (20.0%) had partial improvement. Two (13.3%) children in the control group and 23 (76.7%) in the VATS group had great improvement in QOL. For children with PH and poor QOL, VATS is better than no treatment. It produces better results with regard to sweating and greater improvement in QOL.
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Phase diagrams of poly(ethylene glycol)/polyacrylate/Na2SO4 systems have been investigated with respect to polymer size and pH. Plasmid DNA from Escherichia coil can depending on pH and polymer molecular weight be directed to a poly(ethylene glycol) or to a polyacrylate-rich phase in an aqueous two-phase system formed by these polymers. Bovine serum albumin (BSA) and E. coil homogenate proteins can be directed opposite to the plasmid partitioning in these systems. Two bioseparation processes have been developed where in the final step the pDNA is partitioned to a salt-rich phase giving a total process yield of 60-70%. In one of them the pDNA is partitioned between the polyacrylate and PEG-phases in order to remove proteins. In a more simplified process the plasmid is partitioned to a PEG-phase and back-extracted into a Na2SO4-rich phase. The novel polyacrylate/PEG system allows a strong change of the partitioning between the phases with relatively small changes in composition or pH. (C) 2012 Elsevier B.V. All rights reserved.
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Snake Venom Metalloproteinases (SVMPs) are the most abundant components present in Viperidae venom. They are important in the induction of systemic alterations and local tissue damage after envenomation. In the present study, a metalloproteinase named BpMPI was isolated from Bothropoides pauloensis snake venom and its biochemical and enzymatic characteristics were determined. BpMPI was purified in two chromatography steps on ion exchange CM-Sepharose Fast flow and Sephacryl S-300. This protease was homogeneous on SOS-PAGE and showed a single chain polypeptide of 20 kDa under non reducing conditions. The partial amino acid sequence of the enzyme showed high similarity with other SVMPs enzymes from snake venoms. BpMPI showed proteolytic activity upon azocasein and bovine fibrinogen and was inhibited by EDTA, 1,10 phenanthroline and beta-mercaptoethanol. Moreover, this enzyme showed stability at neutral and alkaline pH and it was inactivated at high temperatures. BpMPI was able to hydrolyze glandular and tissue kallikrein substrates, but was unable to act upon factor Xa and plasmin substrates. The enzyme did not induce local hemorrhage in the dorsal region of mice even at high doses. Taken together, our data showed that BpMP-I is in fact a fibrinogenolytic metalloproteinase and a non hemorrhagic enzyme. (C) 2011 Elsevier Inc. All rights reserved.
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Babassu is considered one of the greatest native resources in the world and its oil is used in body and hair formulations. The aim of this study was to evaluate the short-term stability in oil-in-water (O/W) nanoemulsions containing babassu oil prepared by emulsification phase inversion submitted to the centrifugation, thermal stress, and heating/cooling cycle tests. The formulations showed no change compared to the droplet size, polydispersity index, pH, and electrical conductivity values after thermal stress and heating/cooling cycle tests. Based on these results, the nanoemulsions obtained can be considered as promising disperse systems for pharmaceutical and cosmetic applications.
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The Dengue has become a global public health threat, with over 100 million infections annually; to date there is no specific vaccine or any antiviral drug. The structures of the envelope (E) proteins of the four known serotype of the dengue virus (DENV) are already known, but there are insufficient molecular details of their structural behavior in solution in the distinct environmental conditions in which the DENVs are submitted, from the digestive tract of the mosquito up to its replication inside the host cell. Such detailed knowledge becomes important because of the multifunctional character of the E protein: it mediates the early events in cell entry, via receptor endocytosis and, as a class II protein, participates determinately in the process of membrane fusion. The proposed infection mechanism asserts that once in the endosome, at low pH, the E homodimers dissociate and insert into the endosomal lipid membrane, after an extensive conformational change, mainly on the relative arrangement of its three domains. In this work we employ all-atom explicit solvent Molecular Dynamics simulations to specify the thermodynamic conditions in that the E proteins are induced to experience extensive structural changes, such as during the process of reducing pH. We study the structural behavior of the E protein monomer at acid pH solution of distinct ionic strength. Extensive simulations are carried out with all the histidine residues in its full protonated form at four distinct ionic strengths. The results are analyzed in detail from structural and energetic perspectives, and the virtual protein movements are described by means of the principal component analyses. As the main result, we found that at acid pH and physiological ionic strength, the E protein suffers a major structural change; for lower or higher ionic strengths, the crystal structure is essentially maintained along of all extensive simulations. On the other hand, at basic pH, when all histidine residues are in the unprotonated form, the protein structure is very stable for ionic strengths ranging from 0 to 225 mM. Therefore, our findings support the hypothesis that the histidines constitute the hot points that induce configurational changes of E protein in acid pH, and give extra motivation to the development of new ideas for antivirus compound design.