197 resultados para HYDRATED PHOSPHOLIPID-BILAYERS
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Phytochromes are red/far-red light photoreceptors that mediate a variety of photomorphogenic processes in plants, from germination to flowering. In addition, there is evidence that phytochromes are also part of the stress signalling response, especially in response to water deficit stress, which is the major abiotic factor limiting plant growth and crop productivity worldwide. In this study, we used the phyA (far red-insensitive; fri), phyB1 (temporary red-insensitive; tri) and phyB2 mutants of tomato (Solanum lycopersicum L.) to study the roles of these three phytochromes in drought stress responses. Compared to wild type (WT) plants grown under water-deficit stress conditions, the fri, tri, and phyB2 mutants did not exhibit altered dry weights, leaf areas, stomatal densities, or stomatal opening. The stomatal conductance of all three mutants was severely reduced under both fully-hydrated and water-deficit conditions. Although relative water contents did change after drought stress in each mutant, the most significant reduction in water potential during water stress was observed in the fri mutant. However, this mutant returned its water status to WT levels during rehydration. Although the phyB2 mutant lost more water from detached leaves during abscisic acid (ABA) treatment, phyB2 behaved like WT plants, indicating that this mutant was not insensitive to ABA. Overall, these results indicate that the phytochromes phyA, phyB1, and phyB2 modulate drought stress responses in tomato.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Thermogravimetric analysis is one of the most common instrumental techniques used for the characterization of pastes, mortars and concretes based on both calcium hydroxide and Portland cement. Important information about pozzolanic materials can be assessed concerning calcium hydroxide consumption and the formation of new hydrated products. Nevertheless, in some cases, problems associated with the overlapped decomposition processes for hydrates make the analysis of obtained data difficult. In this paper, the use of high-resolution thermogravimetric analysis, a powerful technique that allows separating decomposition processes in analysis of hydrated binders, was performed for spent FCC catalyst-Portland cement pastes. These pastes were monitored for 1, 4, 8 h and 1, 2, 3, 7 and 28 curing days. In order to study the influence of the pozzolanic material (spent FCC catalyst), Portland cement replacements of 5, 15 and 30 % by mass were carried out. The presence of spent FCC catalyst in blended pastes modified the amount and the nature of the formed hydrates, mainly ettringite and stratlingite.
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ObjectivesTo evaluate the influence of different toothpaste abrasives on the bristle wear and bristle tip morphology of toothbrushes with different degrees of hardness.Material and methodsNinety samples of bovine incisor teeth were used in this study. The samples were randomly divided into three groups according to the bristle hardness of the toothbrush used: soft bristles (S); extra-soft bristles (ES); hard bristles (H). The toothbrushes of each group were randomly divided into six subgroups with five toothbrushes each, according to the abrasive of the toothpaste used in the simulation: Negative control (distilled water); toothpaste 1 (silica); toothpaste 2 (hydrated silica); toothpaste 3 (calcium carbonate, calcium bicarbonate and silica); toothpaste 4 (tetrapotassium pyrophosphate, silica and titanium dioxide); toothpaste 5 (calcium carbonate). The samples were placed in a toothbrushing simulating machine that simulating three months of brushing. The toothbrush bristles were evaluated by the bristle wear index, and the bristle tips morphology was evaluated by the bristle tip morphology index.ResultsThe ES brush presented the highest bristle wear among the toothbrushes. Additionally, the S brushes showed better morphology of the bristles followed by ES and H brushes. The type of abrasive only influenced the bristle tip morphology of the ES brushes. The toothpaste 3 induced the worse bristle tip morphology than all the other toothpastes.ConclusionsDifferent abrasives have influence only on the bristle tip morphology of the ES brushes.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work shows the preparation and characterization of the new nanocomposites based on fibroin and biocellulose. Bacterial cellulose (BC) is an exopolysaccharide produced by bacteria of the genus Gluconacetobacter, which it has identical chemical structure of the cellulose from plants and it has gained attention in the field of research for its unique properties as excellent mechanical properties when dry and hydrated , higher capacity of water retention, moldability , biodegradability and excellent biological affinity . Silk fibroin (SF) is a structural protein present in the cocoon of the silkworm, Bombyx mori, has been identified as suitable for developing optical devices, tissue engineering application, enzyme immobilization, controlled release drug agent biopolymer. Silk fibroin/bacterial cellulose nanocomposite films were prepared impregnating different cellulose charges (0.5 %, 1.0 %, 1.5 %, 2.5 %, 5.0 % and 10.0 %) weight/weight. According mechanical tests and water and Paynes's cup permeability showed that SF/BC 1% nanocomposite has the most relevant results. Poliethylenoglicol (PEG) containing SF films improved optical and mechanical properties when compared to pristine SF film. New SF/BC nanocomposites could be applied in Medicine, as biodegradable packaging and flexible substrates for OLEDs.
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Currently has few studies today concerning the behavior of the ethyl alcohol hydrated combustible in the geological environment, results of eventual spill or leaks in a wide transport chain and distribution. This work discusses the results of an experiment in laboratorial scale, that involves the monitoring of alterations in physical properties a simulate leak of alcohol in a tank with sand saturated in water, during 4920 hours. Are applied electrical resistivity, induced polarization and spontaneous potential geophysical methods. The electric resistivity is clearly correlating to the ethanol degradation pattern. The chargeability demonstrated sensibility to this pattern, while the natural electric potential revealed direct association with the oscillations of groundwater level. The variability of the physical parameters monitoring probable control for ethanol degradation process in environment study.
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Pós-graduação em Agronomia (Agricultura) - FCA
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The development of a reliable technique to freeze epididymal semen would provide a unique opportunity to preserve valuable genetic material from unexpectedly lost stallions. The aim of this study was to compare the apoptotic indices of sperm obtained from ejaculate, sperm recently recovered from the epididymides (EP), and sperm recovered from epididymides stored at 5 C for 24 hours (EP-stored). For the first category, two ejaculates from seven stallions were collected and then submitted to cryopreservation using an egg yolk-based extender. One week after the last semen collection, the stallions were submitted to bilateral orchiectomy, and sperm from one of the cauda epididymis was harvested immediately after castration (EP). The remaining testicle was stored in a passive refrigeration container at 5 C for 24 hours before the cauda epididymal sperm was harvested (EP-stored). Sperm harvesting from the epididymis for EP and EP-stored was performed by retrograde flushing of the caudal portion of the epididymis using a skim milk-based extender. The recovered sperm was then cryopreserved using the egg yolk-based extender. Sperm motility parameters were studied by computerassisted semen analysis, and apoptosis was estimated by measuring caspase activity and membrane phospholipid translocation using epifluorescence microscopy. The samples were evaluated immediately (0 hour) and 8 hours after thawing. At 0 hour, no differences in sperm parameters were observed among the groups, but after 8 hours, significant statistical differences were observed in sperm motility parameters and plasma membrane integrity among the treatment groups. In addition, viable cells with no apoptotic signs were more prevalent in EP and EP-stored, suggesting that epididymal sperm is less sensitive to the cold shock caused by sperm cryopreservation.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)