1000 resultados para Alto rendimento


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The corn cob is an agricultural by-product still little used, this in part due to the low knowledge of the biotechnological potential of their molecules. Xylan from corn cobs (XSM) is a polysaccharide present in greater quantity in the structure of plant and its biotechnology potential is little known. This study aimed to the extraction, chemical characterization and evaluation of biological activities of xylan from corn cobs. To this end, corncobs were cleaned, cut, dried and crushed, resulting in flour. This was subjected to a methodology that combines the use of alkaline conditions with waves of ultrasound. After methanol precipitation, centrifugation and drying was obtained a yield of 40% (g/g flour). Chemical analysis indicated a high percentage of polysaccharides in the sample (60%) and low contamination by protein (0.4%) and phenolic compounds (> 0.01%). Analysis of monosaccharide composition indicated the presence of xylose:glucose:arabinose:galactose:mannose:glucuronic acid in a molar ratio 50:20:15:10:2.5:2.5. The presence of xylan in the sample was confirmed by nuclear magnetic resonance (¹H and ¹³C) and infrared spectroscopy (IR). Tests were conducted to evaluate the antioxidant potential of XSM. This showed a total antioxidant capacity of 48.45 EAA/g sample. However, did not show scavenging activity of superoxide and hydroxyl radical and also reducing power. But, showing a high capacity chelating iron ions with 70% with about 2 mg/mL. The ability to XSM to influence cell proliferation in culture was also evaluated. This polymer did not influence the proliferation of normal fibroblast cells (3T3), however, decreased the rate of proliferation of tumor cells (HeLa) in a dose-dependent, reaching an inhibition of about 50% with a concentration around 2 mg/mL. Analyzing proteins related to cell death, by immunoblotting, XSM increases the amount of Bax, Bcl-2 decrease, increase cytochrome c and AIF, and reduce pro-caspase-3, indicating the induction of cell death induced apoptosis dependent and independent of caspase. XSM did not show anticoagulant activity in the PT test. However, the test of activated partial thromboplastin time (aPTT), XSM increased clotting time at about 5 times with 600 μg of sample compared with the negative control. The presence of sulfate on the XSM was discarded by agarose gel electrophoresis and IR. After carboxyl-reduction of XSM the anticoagulant activity decreased dramatically. The data of this study demonstrate that XSM has potential as antioxidant, antiproliferative and anticoagulant compound. Future studies to characterize these activities of XSM will help to increase knowledge about this molecule extracted from corn and allow their use in functional foods, pharmaceuticals and chemical industries.

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Seaweeds sulfated polysaccharides have been described as having various pharmacological activities. However, nothing is known about the influence of salinity on the structure of sulfated polysaccharides from green seaweed and pharmacological activities they perform. Therefore, the main aim of this study was to evaluate the effect of salinity of seawater on yield and composition of polysaccharides-rich fractions from green seaweed Caulerpa cupressoides var. flabellata, collected in two different salinities beaches of the coast of Rio Grande do Norte, and to verify the influence of salinity on their biological activities. We extracted four sulfated polysaccharides-rich fractions from C. cupressoides collected in Camapum beach (denominated CCM F0.3; F0.5; F1.0; F2.0), which the seawater has higher salinity, and Buzios beach (denominated CCB F0.3; F0.5; F1.0; F2.0). Different from that observed for other seaweeds, the proximate composition of C. cupressoides did not change with increased salinity. Moreover, interestingly, the C. cupresoides have high amounts of protein, greater even than other edible seaweeds. There was no significant difference (p>0.05) between the yield of polysaccharide fractions of CCM and its CCB counterparts, which indicates that salinity does not interfere with the yield of polysaccharide fractions. However, there was a significant difference in the sulfate/sugar ratio of F0.3 (p<0.05) and F0.5 (p<0.01) (CCM F0.3 and CCB F0.5 was higher than those determined for their counterparts), while the sulfate/sugar ratio the F1.0 and F2.0 did not change significantly (p>0.05) with salinity. This result suggested that the observed difference in the sulfate/sugar ratio between the fractions from CCM and CCB, is not merely a function of salinity, but probably also is related to the biological function of these biopolymers in seaweed. In addition, the salinity variation between collection sites did not influence algal monosaccharide composition, eletrophoretic mobility or the infrared spectrum of polysaccharides, demonstrating that the salinity does not change the composition of sulfated polysaccharides of C. cupressoides. There were differences in antioxidant and anticoagulant fractions between CCM and CCB. CCB F0.3 (more sulfated) had higher total antioxidant capacity that CCM F0.3, since the chelating ability the CCM F0.5 was more potent than CCB F0.5 (more sulfated). These data indicate that the activities of sulfated polysaccharides from CCM and CCB depend on the spatial patterns of sulfate groups and that it is unlikely to be merely a charge density effect. C. cupressoides polysaccharides also exhibited anticoagulant activity in the intrinsic (aPTT test) and extrinsic pathway (PT test). CCB F1.0 and CCM F1.0 showed different (p<0,001) aPTT activity, although F0.3 and F0.5 showed no difference (p>0,05) between CCM and CCB, corroborating the fact that the sulfate/sugar ratio is not a determining factor for biological activity, but rather for sulfate distribution along the sugar chain. Moreover, F0.3 and F0.5 activity in aPTT test was similar to that of clexane®, anticoagulant drug. In addition, F0.5 showed PT activity. These results suggest that salinity may have created subtle differences in the structure of sulfated polysaccharides, such as the distribution of sulfate groups, which would cause differences in biological activities between the fractions of the CCM and the CCB

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In recent years, the area of advanced materials has been considerably, especially when it comes to materials for industrial use, such as is the case with structured porosity of catalysts suitable for catalytic processes. The use of catalysts combined with the fast pyrolysis process is an alternative to the oxygenate production of high added value, because, in addition to increasing the yield and quality of products, allows you to manipulate the selectivity to a product of interest, and therefore allows greater control over the characteristics of the final product. Based on these arguments, in this work were prepared titanium catalysts supported on MCM-41 for use in catalytic pyrolysis of biomass, called elephant grass. The reactions of pyrolysis of biomass were performed in a micro pyrolyzer, Py-5200, coupled to GC / MS, the company CDS Corporation, headquartered in the United States. The catalysts Ti-MCM-41 in different molar ratios were characterized by XRD, TG / DTG, FT-IR, SEM, XRF, UV-visible adsorption of nitrogen and the distribution of particle diameter and specific surface area measurement by the BET method. From the catalytic tests it was observed that the catalysts synthesized showed good results for the pyrolysis reaction.The main products were obtained a higher yield of aldehydes, ketones and furan. It was observed that the best reactivity is a direct function of the ratio Si/Ti, nature and concentration of the active species on mesoporous supports. Among the catalysts Ti-MCM-41 (molar ratio Si / Ti = 25 and 50), the ratio Si / Ti = 25 (400 ° C and 600 ° C) favored the cracking of oxygenates such as acids , aldehydes, ketones, furans and esters. Already the sample ratio Si / Ti = 50 had the highest yield of aromatic oxygenates

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O presente estudo teve como objetivo avaliar o rendimento da espermatogênese de cutias criadas em cativeiro, por intermédio das razões encontradas entre tipos celulares do epitélio seminífero. Os resultados apontaram que o rendimento da espermatogênese da cutia dos nove aos quatorze meses de idade não chegou a um ponto de estabilização. O coeficiente de eficiência de mitoses espermatogoniais não aumentou com a idade. O rendimento meiótico, o rendimento geral da espermatogênese e o índice de células de Sertoli mostraram variações numéricas em função da idade, entretanto, não detectadas estatisticamente.

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This study investigated the impact of pulp hexenuronic acids (HexAs) content on pulping yield by changing cooking reaction temperature. The bleachability of pulps containing variable amounts of HexAs was also investigated. The cooking at 170 degrees C produced pulp of kappa number, HexAs and screen yield of 16.2, 49.4 mmol/kg and 50.2%, respectively, whereas the cooking at 156 degrees C resulted pulp of kappa 17.0, 61.3 mmol/kg HexAs and 50.8% screened yield. The pulp produced at lower cooking temperature also showed better bleachability as evaluated by the total amount of active chlorine required to achieve 90% ISO. The sequence OAHTD(EP) DD showed the lowest bleaching performance among all.

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The objective of this study was to evaluate the processing methods (F-1 = to remove skin with pliers and then to cut in fillets; F-2 = cut in fillet and then to remove skin with knife and pliers help) and weight categories (W-1=250-300 g; W-2=301-350 g; W-3 = 351-400 g and W-4 = 401-450 g), on the carcass (CY), fillet (FY) and skin yield of Nile tilapia. Forty-eight fishes were used in a completely randomized design. There was effect for the processing method, being the F-1 mean (56.43 and 36.67 %) higher to the F-2 (53.46 and 32.89%) for CY and FY respectively. For the weight categories, W-1 (56.49 and 37.34%) and W-2 (56.34 and 36.40%) were superior as compared to W-3 (53.27 and 31.98%) and W-4 (53.71 and 33.42%), respectively for CY and FY. Crude skin percentage, clean and of fleshed were higher for F-2, but there was no effect for weight categories. The F-1 processing method promoted the best yield and skin results, and for the weight categories W-1 and W-2 higher yields.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The objective of the present work was evaluate two techniques of smoking, the hot traditional and with use of smoke natural aroma or "liquid smoke", having as control Perna perna mussels vapor cooked. Sensorial characteristics were appraised (appearance, color, aroma, texture, flavor and salt tenor) and yield processing. The experimental design was completely randomized with three treatments (T1 = smoked with liquid smoke; T2 = traditional smoked and T3 = just cooked, control), with nine repetitions. For sensorial analysis 30 people were used, where each one was considered a block. There was significant difference for processing performance among treatments (P<0.05), however there was not significant difference independent of smoked technique applied. Nevertheless, smoking technique using smoke natural aroma was more attractive, presenting better results with relationship to sensorial characteristics and final product packaged for commercialization.

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A incidência de hastes ocas em brócolis (Brassica oleracea L. var. italica Plenck) depende de vários fatores que afetam a absorção e o transporte de B, elemento responsável pelo aparecimento dessa desordem fisiológica. O trabalho avaliou os efeitos de quatro níveis de nitrogênio e dois níveis de boro e da interação entre eles na incidência de hastes ocas e na produção de brócolis. As doses de N (100, 150, 200 e 250 kg ha-1) foram divididas em quatro aplicações iguais aos 15, 30, 45 e 60 dias após o transplante. O boro (0, 4 e 8 kg ha-1) foi aplicado metade no plantio e a outra metade em cobertura aos 45 dias após o transplante. A massa média das inflorescências e a produção total foram diminuídas com a aplicação de B em função do crescimento mais lento das plantas provocado pela toxicidade desse elemento. Contudo, nas áreas não adubadas com B, a porcentagem de plantas com hastes ocas foi, em média, de 44,14%, sendo que a incidência dessa anomalia sofreu drástica redução com a aplicação de B, onde a maior dose (8 kg ha-1) resultou em apenas 4,52% de inflorescências afetadas. Doses de N superiores a 215,4 kg ha-1 aumentaram o número de plantas com hastes ocas somente nas áreas que não receberam B.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Um experimento foi conduzido com o objetivo de avaliar diferentes níveis de aminoácidos e de cálcio para frangos de corte no período de 22 a 42 dias de idade. Avaliou-se o desempenho, o rendimento de carcaça e a excreção de cálcio. Foram utilizadas 540 aves, machos, da marca comercial Cobb, distribuídas em delineamento inteiramente casualizado, em esquema fatorial 3x2, ou seja, 3 níveis de aminoácidos (metionina, metionina+cistina, lisina e treonina - 100%, 125% e 150% NRC,1994) e 2 níveis de cálcio (75% e 100% NRC,1994), com 3 repetições de 30 aves cada. Os aminoácidos estudados foram metionina, metionina+cistina, lisina e treonina. O desempenho das aves foi avaliado pelo peso vivo, ganho de peso, consumo de ração e conversão alimentar. O rendimento de carcaça e a percentagem de cada parte foram avaliados de 2 aves de cada repetição, escolhidas ao acaso, perfazendo um total de 6 animais por tratamento. O rendimento de carcaça foi realizado após o abate levando-se em consideração a percentagem de peito, pernas (coxa+sobrecoxa), asas, dorso, cabeça+pescoço e pés em relação à carcaça eviscerada. Além disso, analisou-se o cálcio excretado pelas aves. Para tanto, utilizou-se 72 aves, alojadas em gaiolas, seguindo o mesmo delineamento descrito anteriormente. Não houve interação entre os fatores estudados para as características avaliadas. As que consumiram dietas com 125% e 150% de aminoácidos apresentaram melhor conversão alimentar. O rendimento de peito foi afetado pelos níveis de cálcio.

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Com o objetivo de estudar o efeito da utilização de doses de fósforo e de potássio no rendimento e nas características agronômicas do algodoeiro (Gossypium hirsutum L.), cv. IAC 20, foi conduzido um experimento em 1994/95, num Latossolo Vermelho-Escuro do Campo Experimental da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-Centro de Pesquisa Agropecuária do Oeste (CPAO), em Ponta Porã, MS. O delineamento experimental foi o de blocos ao acaso, num esquema fatorial 3 x 5, com quatro repetições. As doses foram de 30, 60 e 90 kg ha-1 de P2O5, na forma de superfosfato triplo; 0, 30, 60, 90 e 120 kg ha-1 de K2O, na forma de KCl. Somente as doses de K2O influenciaram significativamente o rendimento de algodão em caroço, a altura da planta e o peso de 100 sementes e dos capulhos.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In maize (Zea mays L.), the inadequate nitrogen supply and planting density are considered limiting factors to the grain yield. The objective of this study was to evaluate the influence of different nitrogen levels and plant densities to the maize yield components and productivity. The experiment was carried out in the Cerrado region, located in the southern of the Maranhao State, Brazil, in a clay Oxisol (Ustox), cropped under the no-tillage system for six years. The randomized completed blocks experimental design with four replications was used, with treatments arrangement in a 5 x 4 factorial. The treatments were a combination of five doses of nitrogen as urea (0, 50, 100, 150 and 200 kg ha(-1)) and four plant densities (25,000; 50,000; 75,000 and 100,000 plants he). The grain number and mass per spike and grain mass per plant were improved by increased N and decreased plant density. Higher incomes of grains were obtained with adding concomitantly in N doses and in plants density. The maximum grain yield (11,9 Mg ha(-1)) was obtained with 120 kg ha(-1) of N and 83,000 plants ha(-1).