913 resultados para in situ SECM hydrogen permeation
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Um experimento foi realizado com o objetivo de avaliar os parâmetros ruminais, a produção de ácidos graxos voláteis e a degradabilidade in situ em tourinhos Santa Gertrudes canulados no rúmen alimentados com dietas compostas de feno de capim-marandu e concentrado. Empregou-se o delineamento em quadrado latino 4 ´ 4, no qual os tratamentos foram compostos dos concentrados, ajustados para ganho de peso corporal (GPC) diário de 0,5 e 1 kg/animal e potencial de fermentação microbiana (y) de 9,5 e 11 g de proteína bruta microbiana/MJ energia metabolizável fermentável. Não foram encontradas interações significativas nem diferenças entre as dietas para pH, concentração molar dos ácidos acético e butírico e proporção molar dos ácidos acético, propiônico e butírico e relação acético:propiônico. Os teores de amônia diferiram entre os potenciais de fermentação microbiana, 14,67 e 20,83 mg/100 mL para baixo e alto, respectivamente, e a concentração molar de ácido propiônico foi diferente entre os potenciais de ganho de peso, 7,62 e 8,94 mM, respectivamente, para baixo e alto ganho de peso. Não foram detectadas diferenças entre dietas para as degradabilidades das frações do feno de capim-marandu e da soja em grão. Houve diferença no parâmetro b e na degradabilidade efetiva a 5%/hora da proteína bruta para os potencias de GPC do milho em grão moído. Para o farelo de soja, ocorreu interação significativa entre os potencias de GPC e de fermentação microbiana para alguns dos parâmetros da MS e PB, o mesmo observado para o farelo de algodão. As diferenças encontradas não justificaram o balanceamento dos concentrados para os diferentes potenciais de produção avaliados.
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This study was undertaken to compare cryotolerance, in terms of viability and resumption of meiosis after warming and culture (24 and 48 h), of ex situ (isolated) and in situ (enclosed in the ovarian tissue) feline cumulusoocyte complexes (COCs) vitrified with DAP 213 (2 M DMSO, 1 M acetamide, 3 M propylene glycol) in cryotubes or Cryotop method. Ovaries were harvested from 49 pubertal queens. of each pair of ovaries, one was dissected to release COCs randomly divided into three groups: fresh COCs (control), ex situ COCs vitrified with DAP 213 and Cryotop. The cortex of the other ovary was sectioned into small fragments (approximately 1.5 mm3) and randomly assigned to be vitrified by DAP 213 or Cryotop. After warming, ex situ and in situ (retrieved form vitrified ovarian tissue) COCs were matured in vitro. Viability of oocytes was highly preserved after warming and culture in all treatments. Proportions of oocytes surrounded by complete layers of viable cumulus cells were remarkably decreased (p < 0.00001) in both vitrification procedures compared to fresh oocytes. Resumption of meiosis occurred in all treatments. After 24 h of culture, results were similar in ex situ and in situ vitrified oocytes regardless of the vitrification protocol used (range 29-40%), albeit lower (p < 0.05) than those of fresh oocytes (65.8%). After 48 h of culture, ex situ oocytes vitrified with Cryotop achieved the rates of meiosis resumption similar to fresh oocytes (53.8% vs 67.5%; p > 0.05) and ex situ and in situ oocytes vitrified with DAP 213 showed similar rates of resumption of meiosis. These findings demonstrated that DAP 213 and Cryotop preserve the viability of ex situ and in situ oocytes, but cumulus cells are highly susceptible to vitrification. However, the capability to resume meiosis evidences that feline immature oocytes vitrified as isolated or enclosed in the ovarian cortex have comparable cryotolerance.
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The objective of this work was to evaluate the effect of diets with different forages (sugarcane, corn silage, hydrolyzed bagasse and sugarcane + corn silage) on the ruminal Fermentation and ruminal nutrients degradability, by the application of bovine somatotropin. Three bovines with ruminal cannulas were used in a factorial scheme (4 x 2). The pH, number of protozoa, ammonia and volatile fatty acids concentration were quantified. The potential and the effective degradability and degradation rate of dry matter and crude protein in each diet were evaluated, beyond gross energy disappearance. There were differences among diets on the effective degradability of dry matter and potential degradability, effective degradability and potentially degradable fraction of crude protein, being verified the same for the rBST application. There was effect of different forages on the variables of ruminal Fermentation. The treatments did not affect the gross energy disappearance. The rBST application did not affect the variables of ruminal fermentation.
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Two experiments were carried out to evaluate the effect of supplementation with different nitrogenous compounds on the activities of carboxymethil cellulase (CMCase) and glutamate dehydrogenase (GDH). In the first experiment, four treatments were evaluated in vitro: cellulose, cellulose with casein, cellulose with urea, and cellulose with casamino acids. After 6, 12 and 24 hours of incubation, CMCase and GDH activity, pH, and concentrations of ammonia nitrogen (AN) and microbial protein were measured. In the three incubation periods, the concentration of AN was higher when urea was used as a supplemental source of nitrogen. The activity of CMCase was higher with the addition of urea and casamino acids when compared with the control and the casein treatment. Supplementation with casamino acids provided higher GDH activity when compared with the control at 6 hours of incubation. At 12 hours of incubation, the GHD activity was also stimulated by casein. At 24 hours, there was no difference in GHD activity among treatments. In the second experiment, three rumen-fistulated bulls were used for in situ evaluation. Animals were fed Tifton hay (Cynodon sp.) ad libitum. The treatments consisted of control (no supplementation), supplementation with non-protein nitrogenous compounds (urea and ammonium sulphate, 9:1) and supplementation with protein (albumin). In treatments with nitrogenous compound supplementation, 1 g of crude protein/kg of body weight was supplied. The experiment was conducted in a 3 × 3 Latin square design. The measurements were performed at 6, 12 and 24 hours after supplementation. No difference in GDH activity was observed among treatments. The control treatment showed higher CMCase activity when compared with the treatments containing supplemental sources of nitrogen. However, urea supplementation provided higher CMCase activity compared to albumin.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Este trabalho foi realizado na Faculdade de Ciências Agrárias Veterinárias - Unesp - Jaboticabal e foi conduzido, com o objetivo de avaliar a influência do método de amostragem do pasto sobre a degradabilidade in situ da matéria seca e da fração fibrosa de capim Marandu, colhido no período seco dos anos de 2003 e 2005. O experimento foi instalado em delineamento de blocos casualizados com parcela subdividida, com três repetições, representadas pelos piquetes amostrados. Nas parcelas, foram avaliados cinco métodos de amostragens de forragem (método do quadrado metálico; método de avaliação através de extrusa de bovino da raça Nelore; método de avaliação por meio de extrusa de bovino Cruzado (Red Angus x Nelore); método de avaliação por meio do pastejo, simulando bovino da raça Nelore; método de avaliação por meio do pastejo, simulando bovino Cruzado (Red Angus x Nelore) e as subparcelas foram constituídas pelos anos de amostragem, 2003 e 2005. Foram determinadas as frações da cinética ruminal: solúvel A; insolúvel potencialmente degradável B; taxa de degradação Kd; degradação potencial (DP) e fração não degradável C da MS e degradação potencial (DP), fração não degradável C e taxa de degradação Kd da FDN e da FDA. de acordo com os resultados obtidos, observou-se que o método do quadrado metálico subestimou as características da degradação do capim. Os métodos do pastejo simulado se assemelharam muito ao das extrusas, no entanto, a prática do simulador é que assegurou a amostragem eficiente, conforme foi constatado pelos dados obtidos no ano de 2003 e 2005.
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Avaliou-se o efeito de enzimas fibrolíticas (celulase e xilanase) sobre a degradabilidade in situ da MS, PB, FDN, FDA e hemicelulose do feno de Tifton-85 (Cynodon spp.) cortado aos 30 e 90 dias e do bagaço de cana, utilizando-se seis bovinos com cânula no rúmen. As enzimas foram extraídas dos fungos Aspergillus niger e Trichoderma longibrachiatum e fornecidas, na quantidade de 0,75 g/kgMS.dia, por meio da cânula ruminal. Os tempos de incubação ruminal foram de 0, 3, 6, 12, 24, 48, 72 e 96 horas. Os resíduos de incubação foram avaliados por meio de microscopia eletrônica de varredura (MEV). O efeito da adição de enzimas sobre a degradação da MS e PB variou em função do volumoso estudado. A degradabilidade efetiva da MS do feno Tifton cortado aos 30 e 90 dias e do bagaço de cana sem a adição de enzimas foi de 61,85; 42,35 e 28,22%, respectivamente, e de 63,51; 40,64 e 31,43%, respectivamente, com a adição das enzimas. Não houve efeito das enzimas sobre a degradação da fibra. As observações ao MEV indicaram aumento da colonização bacteriana sobre a parede celular com a suplementação enzimática. A adição de enzimas fibrolíticas na dieta de ruminantes apresentou efeito pouco expressivo sobre os parâmetros de degradação ruminal dos volumosos estudados.
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O objetivo deste ensaio foi avaliar o efeito do emurchecimento e da adição de fubá durante o processo de ensilagem da alfafa sobre a degradabilidade in situ da matéria seca (MS), da fibra em detergente neutro (FDN) e da proteína bruta (PB). Foram utilizados três bovinos adultos mestiços fistulados no rúmen, nos quais foram incubados seis tipos de silagens (1-alfafa fresca; 2-alfafa fresca +5% de fubá; 3-alfafa fresca +10% de fubá; 4-alfafa emurchecida; 5-alfafa emurchecida + 5% de fubá ; 6-alfafa emurchecida + 10% de fubá) durante três tempos de incubação (6, 24, 96 horas). O delineamento experimental foi em parcelas subdivididas, com tratamentos em parcelas, tempos em subparcelas e animais como blocos. A adição de fubá à silagem aumentou (P<0,05) a degradação da MS e FDN com o tempo de incubação. O emurchecimento proporcionou diminuição (P<0,05) na degradabilidade dos nutrientes, entretanto esse efeito foi ligeiramente contornado pela adição de 10% de fubá. Os tratamentos com a adição de fubá e o emurchecimento proporcionaram maior taxa de degradabilidade da MS de fração b, entretanto o emurchecimento diminuiu o potencial de degradação a, enquanto que a adição de níveis de fubá não alterou a degradabilidade da MS dessa fração. A degradação da fração b da FDN aumentou com a adição de fubá e diminuiu com o emurchecimento, entretanto houve aumento dessa fração quando se adicionou fubá à forragem emurchecida. A degradação da fração a da PB aumentou com a adição de fubá e diminuiu com o emurchecimento; para a fração b ocorreu o inverso. Concluiu-se que a prática do emurchecimento, por reduzir a fração solúvel da forragem, diminui a degradabilidade dos nutrientes da silagem de alfafa, que no entanto pode ser melhorada com a adição de fubá.
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O objetivo deste trabalho foi o de avaliar o efeito das silagens de três híbridos de sorgo: granífero (Conti-Silo, de porte baixo), duplo propósito (Conti-Silo-03, de porte médio) e forrageiro (547-F, de porte alto) e de três épocas distintas (aos 105, 112 e 119 dias após a semeadura) sobre a degradabilidade in situ da matéria seca (MS) e da fibra em detergente neutro (FDN). Foram utilizados três bovinos adultos mestiços fistulados no rúmem, distribuídos em um delineamento experimental em parcelas subdivididas, com três tempos de incubação (6, 24, 96 horas). Houve diferença (P<0,05) nas frações de desaparecimento da MS e de FDN após 6, 24 e 96 horas de incubação ruminal entre as diferentes silagens. Quanto à época de colheita, a diferença na degradação de MS foi observada após 96 horas de incubação, destacando-se a variedade de duplo propósito, superior nos três diferentes cortes. Com a maturação, observou-se tendência de aumento na fração degradável da MS, porém esse efeito foi menos evidente nas silagens de sorgo forrageiro. Para a FDN não houve diferença (P<0,05) entre silagens em nenhum dos tempos de incubação.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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With the growth and development of modern society, arises the need to search for new raw materials and new technologies which present the "clean" characteristic, and do not harm the environment, but can join the energy needs of industry and transportation. The Moringa oleifera Lam, plant originating from India, and currently present in the Brazilian Northeast, presents itself as a multi-purpose plant, can be used as a coagulant in water treatment, as a natural remedy and as a feedstock for biodiesel production. In this work, Moringa has been used as a raw material for studies on the extraction and subsequently in the synthesis of biodiesel. Studies have been conducted on various techniques of Moringa oil extraction (solvents, mechanical pressing and enzymatic), being specially developed an experimental design for the aqueous extraction with the aid of the enzyme Neutrase© 0.8 L, with the aim of analyzing the influence variable pH (5.5-7.5), temperature (45-55°C), time (16-24 hours) and amount of catalyst (2-5%) on the extraction yield. In relation to study of the synthesis of biodiesel was initially carried out a conventional transesterification (50°C, KOH as a catalyst, methanol and 60 minutes reaction). Next, a study was conducted using the technique of in situ transesterification by using an experimental design variables as temperature (30-60°C), catalyst amount (2-5%), and molar ratio oil / ethanol (1:420-1:600). The extraction technique that achieved the highest extraction yield (35%) was the one that used hexane as a solvent. The extraction using 32% ethanol obtained by mechanical pressing and extraction reached 25% yield. For the enzymatic extraction, the experimental design indicated that the extraction yield was most affected by the effect of the combination of temperature and time. The maximum yield obtained in this extraction was 16%. After the step of obtaining the oil was accomplished the synthesis of biodiesel by the conventional method and the in situ technique. The method of conventional transesterification was obtained a content of 100% and esters by in situ technique was also obtained in 100% in the experimental point 7, with a molar ratio oil / alcohol 1:420, Temperature 60°C in 5% weight KOH with the reaction time of 1.5 h. By the experimental design, it was found that the variable that most influenced the ester content was late the percentage of catalyst. By physico-chemical analysis it was observed that the biodiesel produced by the in situ method fell within the rules of the ANP, therefore this technique feasible, because does not require the preliminary stage of oil extraction and achieves high levels of esters
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Microalgae are microscopic photosynthetic organisms that grow rapidly and in different environmental conditions due to their simple cellular structure. The cultivation of microalgae is a biological system capable of storing solar energy through the production of organic compounds via photosynthesis, and these species presents growth faster than land plants, enabling higher biomass yield. Thus, it is understood that the cultivation of these photosynthetic mechanisms is part of a relevant proposal, since, when compared to other oil producing raw materials, they have a significantly higher productivity, thus being a raw material able to complete the current demand by biodiesel . The overall aim of the thesis was to obtain biofuel via transesterification process of bio oil from the microalgae Isochrysis galbana. The specific objective was to estimate the use of a photobioreactor at the laboratory level, for the experiments of microalgae growth; evaluating the characteristics of biodiesel from microalgae produced by in situ transesterification process; studying a new route for disinfection of microalgae cultivation, through the use of the chemical agent sodium hypochlorite. The introduction of this new method allowed obtaining the kinetics of the photobioreactor for cultivation, besides getting the biomass needed for processing and analysis of experiments in obtaining biodiesel. The research showed acceptable results for the characteristics observed in the bio oil obtained, which fell within the standards of ANP Resolution No. 14, dated 11.5.2012 - 18.5.2012. Furthermore, it was demonstrated that the photobioreactor designed meet expectations about study culture growth and has contributed largely to the development of the chosen species of microalgae. Thus, it can be seen that the microalgae Isochrysis galbana showed a species with potential for biodiesel production
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Ages of zircon from sedimentary samples of Rio Parana Formation, belonging of Bauru Group, north of Parana Basin, Brazil, has been determined by zircon Fission Track and U-Th-Pb in situ dating methods. The obtained ages are from same zircon grain that provided information on the source areas for the sediments and the morphotectonic events.
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Objective. To investigate and compare the protective impact of the in situ formed salivary pellicle on enamel and dentine erosion caused by different acids at pH 2.6. Methods. Bovine enamel and dentine samples were exposed for 120 min in the oral cavity of 10 healthy volunteers. Subsequently, enamel and dentine pellicle-covered specimens were extraorally immersed in 1 ml hydrochloric, citric or phosphoric acid (pH 2.6, 60 s, each acid n=30 samples). Pellicle-free samples (each acid n=10) served as controls. Calcium release into the acid was determined by atomic absorption spectroscopy. The data were analysed by two-way ANOVA and Tukey's test (alpha=0.05). Results. Pellicle-covered samples showed significantly less calcium loss compared to pellicle-free samples in all acid groups. The mean (SD) pellicle protection (% reduction of calcium loss) was significantly better for enamel samples [60.9 (5.3)] than for dentine samples [30.5 (5.0)], but revealed no differences among the acids. Conclusion. The efficacy of the in situ pellicle in reducing erosion was 2-fold better for enamel than for dentine. Protection of the pellicle was not influenced by the kind of acid when enamel and dentine erosion was performed at pH 2.6.