968 resultados para Residue lignocellulosic


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Cystatins form a large family of cysteine protease inhibitors found in a wide arrange of organisms. Studies have indicated that mammalian cystatins play important roles under both physiological and pathological conditions. However, much less is known about fish cystatins. In this report, we described the identification and analysis of a cystatin B homologue, SmCytB, from turbot Scophthalmus maximus. The open reading frame of SmCytB is 300 bp, which encodes a 99-residue protein that shares high levels of sequence identities with the cystatin B of a number of fish species and contains the conserved cysteine protease inhibitor motif of cystatin B. Constitutive expression of SmCytB is high in muscle, brain, heart and liver, and low in spleen. blood, gill and kidney. Bacterial infection upregulates SmCytB expression in kidney, spleen, liver and brain but not in muscle or heart. Functional analysis showed that recombinant SmCytB purified from Escherichia colt exhibits apparent cysteine protease inhibitor activity. Transient overexpression of SmCytB in head kidney macrophages enhances macrophage bactericidal activity probably through a nitric oxide-independent mechanism. These results indicate that SmCytB is involved in the immune defense of turbot against bacterial infection. (C) 2010 Elsevier Ltd. All rights reserved.

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An improved method for the determination of phosphorus in natural waters, aquatic organisms and sediments by ignition method is proposed. The recoveries of phosphorus (P) from selected inorganic and organic P-containing compound standards after ignition with different auxiliaries, such as MgSO4, Mg(NO3)(2), MgO2, Mg(Ac-2) and CaCl2, were compared. We found that the phosphorus from most compound standards could not be completely recovered when these compounds were ignited (450-500degreesC) with the MgSO4 as auxiliary and the baked residue was extracted with 0.2 mol l(-1) HCl for 30min at 80degreesC or at room temperature. P recoveries, for example, were poor, less than 85%, if pyrophosphate and metaphosphate were ignited with the addition Of MgSO4 prior to the extraction of the baked residue with 0.2 mol l(-1) HCl at 80degreesC for 30 min. In contrast, MgO2, Mg(Ac)(2) and CaCl2, as well as Mg(NO3)(2), could all yield complete P recoveries at routine ashing temperatures (450-500degreesC). The results demonstrate that MgC12 is a more effective auxiliary agent for the determination of phosphorus in natural waters, aquatic organisms and sediments by ignition method than MgSO4 which is commonly used. (C) 2003 Elsevier Science Ltd. All rights reserved.

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Phosphorus recoveries from selected inorganic and organic P-containing compounds after ignition with auxiliaries, such as MgSO4, Mg (NO3)(2), MgCl2, Mg (Ac)(2) and CaCl2 were studied. It was found that the phosphorus could not be completely recovered when most P-containing compounds were ignited with MgSO4 at temperature not higher than 500degreesC if the baked residue was extracted with 0.2 mol/L HCl for 30 min at 80degreesC or at room temperature. In contrast, MgCl2, Mg(Ac)(2) and CaCl2, as well as Mg(NO3)(2), could all yield complete P recoveries. We suggest that MgCl2 rather than MgSO4, which is usually used, should be utilized as ashing auxiliary agent in the P extraction by ignition method. Although Mg (NO3)(2) is a highly effective auxiliary agent, yet interference from MgSO4, danger of explosion, toxicity of nitrogen dioxide and more manipulation steps may limit its widespread utilization. It is suggested that if sediment is ignited with MgCl2, the extraction of residue with 0.2 mol/L HCl for 30 min at 80degreesC could give good result.

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The residues of enrofloxacin and its metabolite in Nile tilapia (Oreochromis niloticus) were studied after oral dose of 50 mg/kg for 7 days. To find the differences between Nile tilapia and Chinese shrimp (Penaeus chinensis), the residues of enrofloxacin in P chinensis were also studied under the same conditions. The results showed that enrofloxacin metabolized into ciprofloxacin in both Nile tilapia and P chinensis, the maximal concentration of enrofloxacin in muscle, liver and plasma of Nile tilapia were 3.61 mu g/g, 5.96 mu g/g, 1.25 mu g/ml respectively, and ciprofloxacin in muscle was 0.22 mu g/g. The maximal concentration of enrofloxacin and ciprofloxacin in P chinensis were 1.68 mu g/g and 0.07 mu g/g respectively. The predicted withdrawal time for Nile tilapia was 22 days, and P. chinensis was 12 days under our experiment conditions. The residues of fitrazolidone [3-(5-nitrofurfurylidenamino)-2-oxazolidinone] and its main metabolite 3-amina-2-oxazolidinone (AOZ) in Nile tilapia were first determined by HPLC/MS. Results showed that after oral dose of 30 mg/kg for 7 days, the maximum concentration of farazolidone in Nile tilapia was 413 mu g/kg after 6 h, whereas AOZ residue reached its maximum (31 mu g/kg) right after stopping treatment. In contrast to the high metabolic rate of furazolidone, AOZ was very difficult to eliminate in vivo, thus the withdrawal time of furazolidone in Nile tilapia was 22 days at least. (c) 2005 Elsevier B.V. All rights reserved.

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An HPLC-UV-MS method for simultaneous identification of predominant phenolics and minor nucleoside derivatives in Gastrodia elata was developed, which was based on their UV and MS characteristics summarized through a series of homemade reference standard experiments. Phenolics showed characteristic UV lambda(max) at 267 nm, [M + NH4](+) base peak in positive mode and [M - H](-) base peak in negative mode while nucleosides exhibited UV lambda(max) at 255 nm, [M + H](+), [M - H + 2H(2)O](-) or [M - H + CH3COOH](-). Phenolics conjugates mainly underwent the consecutive loss of gastrodin residue (- 268 U) and the combined loss of H2O and CO2 from the citric acid unit under negative MS/MS conditions whereas nucleosides simply lost the ribose (- 132 U) under positive MS/MS conditions. According to these characteristics, a special pattern under MS/MS conditions and reported compound data for G. elata in the literature, not only 15 phenolics were identified but also 6 nucleoside derivatives were identified. Among these compounds, seven phenolics and three nucleoside derivatives have not been reported yet from G. elata.

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Chemical weathering intensity of loess deposits is largely determined by three factors: chemical weathering in source regions, grain size and post-depositional weathering. The third factor is influenced by climatic conditions such as precipitation and temperature, and the dust sedimentation rate in the area of deposition. Previous studies have shown that the (CaO+MgO+Na2O)/TiO2 ratio of decarbonated residue from loess is independent of grain size changes and thus is a reliable proxy for chemical weathering. However, the validity of (CaO+MgO+Na2O)/TiO2 to describe changes in monsoon intensity requires further study. In this study, 48 sections over the last glacial-interglacial cycle on the Chinese Loess Plateau were sampled, and the major elemental concentrations of 248 decarbonated residue samples were measured to investigate the utility of the (CaO+MgO+Na2O)/TiO2 ratio as a proxy for changes in monsoon intensity. Results show that the (CaO+MgO+Na2O)/TiO2 ratio, is relatively more sensitive to climate change than other indexes independent of grain size, and is not affected substantially by sedimentation rate. Assuming the weathering regime is relatively stable in the loess source regions, the (CaO+MgO+Na2O)/TiO2 ratio is a reliable proxy for the intensity of summer monsoon. A decreasing (CaO+MgO+Na2O)/TiO2 ratio from northwest to southeast both in loess and paleosols indicates that the Chinese Loess Plateau is in the control of the East Asian summer monsoon during both interglacial and glacial times. In addition, the spatial distributions of (CaO+MgO+Na2O)/TiO2 ratios show a greater north-south gradient during interglacial periods than during glacial periods. This may suggest that the spatial precipitation gradient, controlled by the summer monsoon, is steeper during interglacials than in glacials.

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The continental mantle geochemical characteristics and crust-mantle evolution in the west of Yangtze Plate was discussed through the study of some within-plate basic-ultrabasic rocks from Lower Proterozoic to Later Paleozoic in this paper. In the Lower Proterozoic, the plate subduction between the pre-Tethys Proterozoic Ocean Plate and paleo-Yangtze Plate induced some basic volcanic formed in the island arc-back arc surrounding, which were represented by Ailaoshan Group-Dibadu Formation-Dahongshan Group, and there existed EM I component in the mantle source. The Middle Proterozoic Caiziyuan peridotite was formed in the epicontinental basin at the ocean-land boundary or within-continent rift basin. Its mantle source could be metasomatized by the dehydration fluid of subducted plate, and much initial radioactive ~(143)Nd was added to the source. In the Later Proterozoic, some rifts at the epicontinent or within-continent was formed due to the pre-Tethys oceanic plate subduction, and within-plate hot-spot Dahongshan diabase came into being. The whole-rock isochronal age of diabase is 1066±110Ma, and its mantle source was enriched Nd isotope and trace element which was related to the primary volatile component from asthenosphere and mantle plume. Its mantle source was included "FOZO" component representing mantle plume. The layer ultramafic rocks located at the Panxi Rift in the Middle-Later Paleozoic were resulted from different period and source. The early ultramafic indicated the incipient action of Panxi Rift, which is residue of continental lithospheric partial melting. Its mantle source involved subducted material and had distinct EM II component. The Emeishan basalt in the Later Paleozoic was typical continental flood basalt and its source also contained EM II component. The subduction of paleo-Tethys Ocean Plate provided essential dynamic condition for the large-scale opening of Panxi Rift, while the mantle plume supplied much material for Emeishan basalt. However, the plume was contaminated by the metasomatized continental mantle lithosphere in its upwelling process, which resulted in the Sr isotopic and incompatible elemental enrichment, and the Nd isotope kept down the weak-depleted character of mantle plume. The magmatic history in the west of Yangtze Plate is the tectonic process between pre-Tethys, paleo-Tethys Oceanic Plate and Yangtze Plate in a long history. Due to the subduction of oceanic plate, the crustal source material took part in the crust-mantle evolution widely. the continental mantle lithosphere in the west of Yangtze Plate was metasomatized by the fluid released by the subducted plate and the primary volatile from deeper mantle, and the mantle source include obvious enriched component.

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The mafic-ultramafic layered intrusions in the Panxi, China contain large V-Ti-magnetite deposits. These layered intrusions are related with the Emeishan continental flood basalts in space and time. Two layered intrusions, Hongge and Xinjie have clear PGE mineralization at the base of the intrusions. Thus the detailed investigations of these two intrusions not only have a geological but also have an economic significance. This thesis aims to characterize the elemental and Sr-Nd isotopic features of diverse rock zones within the intrusion on the basis of systematic studies of the major, trace element and isotope ratios, therefore to constrain the petrogenesis, mantle source and evolution of the Hongge and Xinjie intrusions. Generally, both Hongge and Xinjie intrusions show the same Fe-Ti-rich and Si-M-poor characteristics. They are also enriched in rare-earth elements (REE) and large-ion lithophile elements (LILE) as well as in Sr-Nd isotope ratios (Hongge: initial Sr = 0.7056-0.7076, ε_(Nd)(t) and (Nd/Sm)_N-ε_(Nd)(t) plots, the Hongge intrusion has a similar elemental and isotopic features to the Emeishan low-Ti (LT) basalts, whereas the Xinjie intrusion was close to the Emeishan high-Ti (HT) basalt. Therefore, the Hongge intrusion may be co-genetic with the LT basalt, formed by the partial melting of the spinel-garnet transition mantle that had a slight enriched isotope character. In contrast, the Xinjie intrusion and the HT basalts are probably derived from the garnet-phases mantle with a primitive isotope character. The involvement of the components of mantle wedge into the source is considered to be the major reason of the REE and LILE enrichment and Nd isotope depletion in the Xinjie intrusion. In contrast with the systematic variations in TiO_2 content, Mg#, transition elements (Ni, Cu, Co), REE concentrations, and La/Yb, La/Sm ratios from the lower zone to upper zone, the different rock zones of the Hongge intrusion have no clear Sr-Nd isotope variations. This suggests that the Hongge intrusions were formed by the crystal fractionation from the same magma source. The rhythm may be formed by slow injection of the co-genetic magma during the crystal fractionation. The increase in K_2O and Al_2O_3 contents, REE abundance, and the degree of the REE fractionation in the base of the intrusion, together with the relatively low ε_(Nd)(t) value, may imply that the base of the Hongge intrusion was contaminated with the local crust rocks. Xinjie intrusion shows the clearly elemental and isotopic differences in diverse cumulus cycles. The observation of the systematic variations in TiO_2 content, Mg# value, transition elements (Ni, Cu, Co), REE concentrations, and La/Yb, La/Sm ratios in first cycle was not occurred in second cumulus cycle. In addition, the ε_(Nd)(t) value in second cumulus cycle is apparently higher than that of the first one. Thus the abruptly elemental and isotopic changes at the base of second cycle demonstrate that there is considerable new and depleted magma addition to the residue magma after the crystallization of the first cycle. These features are very similar to those of the well-known PGE-rich Bushveld and Stillwater layered intrusions. The PGE mineralization in Xinjie intrusion is much better than in Hongge intrusion. Therefore, the layered intrusion similar to the Xinjie in Panxi area posses the better prospects for the PGE deposits.

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RESUMO: Os efeitos de fatores climáticos sobre a dinâmica da decomposição de resíduos culturais, apesar de importantes para a compreensão de processos como a formação da matéria orgânica, são pouco conhecidos e estudados, sendo raros os estudos, principalmente os de longa duração. O objetivo deste trabalho foi avaliar os impactos das temperaturas máxima e mínima, da quantidade de chuvas (precipitação) e da evaporação sobre a evolução da decomposição de resíduos de aveia e trigo, em semeadura direta e convencional, utilizando-se dados de um ensaio de longa duração (12 anos) conduzido no campo experimental da Embrapa Soja, em Londrina, PR. Enquanto as temperaturas mostraram não ser um fator limitante à decomposição dos resíduos, as maiores quantidades de chuvas foram diretamente relacionadas às maiores taxas de decomposição dos resíduos estudados, principalmente no sistema plantio convencional. ABSTRACT: Climatic effect studies on residue decomposition are scarce in spite of its importance to understand the formation of the soil organic matter. The infl uence of maximum and minimum temperatures, rain and evaporation was studied on oat and wheat residues with emphasis on decay levels, considering tillage and no-tillage practices, over 12 years, in a clayish soil at the experimental fi eld of Embrapa Soybean, Londrina-PR, Brazil. While temperatures showed no limitations on decomposition of residues studied, rainfall was directly associated with high levels of residue decay. Decomposition levels were greater for tillage systems in both crops.

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Copper nanoparticles were deposited onto mesoporous SBA-15 support via two different routes: post-grafting method and incipient wet impregnation method. Both XRD and TEM reveal that the post-grafting can make Cu particles very small in size and highly dispersed into channels of SBA-15, while the impregnation method mainly forms large Cu particles on the external surface of SBA-15. TPR experiments show that CuO species formed by the post-grafting method is more reducible than that prepared by the impregnation method. The catalytic activity tests for CO oxidation manifests that the sample prepared by the post-grafting method has a much higher activity than that prepared by the impregnation method, with a lowering of 50 degrees C for T-50, showing a strong dependence of catalytic activity on the size and dispersion of Cu particles. Besides the preparation procedure, other factors including calcination temperature, reduction treatment, copper loading as well as the feed composition, have an important effect on the catalytic activity. The best performance was obtained when the catalyst was calcined at 500 degrees C and reduced at 550 degrees C. The calcination and reduction treatment at high temperature have been found to be necessary to completely remove the organic residue and to generate active metallic copper particles. (c) 2005 Elsevier B.V. All rights reserved.

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Sorghum is the fifth most important cereal worldwide and is a major source of agricultural residues in tropical regions. Bioconversion of whole sorghum crop residues comprising stalks, leaves, peduncles and panicles to ethanol has great potential for improving ethanol yield per sorghum crop cultivated, and for sustainable biofuel production. Effective pretreatment of sorghum lignocellulosic biomass is central to the efficiency of subsequent fermentation to ethanol. Previous studies have focused on bioconversion of sorghum stalks and/or leaves only to bioethanol, but the current study is the first report dealing with whole crop residues. We specifically focused on the impact of Nigerian sorghum cultivation location and cultivar type on the potential ethanol yield from whole sorghum crop residues. Efficient bioconversion of whole sorghum residues to ethanol provides a sustainable route for utilisation of crop residues thereby providing a non-food feedstock for industrial scale bioethanol production.

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Wydział Biologii: Instytut Biologii Molekularnej i Biotechnologii

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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In gesture and sign language video sequences, hand motion tends to be rapid, and hands frequently appear in front of each other or in front of the face. Thus, hand location is often ambiguous, and naive color-based hand tracking is insufficient. To improve tracking accuracy, some methods employ a prediction-update framework, but such methods require careful initialization of model parameters, and tend to drift and lose track in extended sequences. In this paper, a temporal filtering framework for hand tracking is proposed that can initialize and reset itself without human intervention. In each frame, simple features like color and motion residue are exploited to identify multiple candidate hand locations. The temporal filter then uses the Viterbi algorithm to select among the candidates from frame to frame. The resulting tracking system can automatically identify video trajectories of unambiguous hand motion, and detect frames where tracking becomes ambiguous because of occlusions or overlaps. Experiments on video sequences of several hundred frames in duration demonstrate the system's ability to track hands robustly, to detect and handle tracking ambiguities, and to extract the trajectories of unambiguous hand motion.

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We propose a new characterization of protein structure based on the natural tetrahedral geometry of the β carbon and a new geometric measure of structural similarity, called visible volume. In our model, the side-chains are replaced by an ideal tetrahedron, the orientation of which is fixed with respect to the backbone and corresponds to the preferred rotamer directions. Visible volume is a measure of the non-occluded empty space surrounding each residue position after the side-chains have been removed. It is a robust, parameter-free, locally-computed quantity that accounts for many of the spatial constraints that are of relevance to the corresponding position in the native structure. When computing visible volume, we ignore the nature of both the residue observed at each site and the ones surrounding it. We focus instead on the space that, together, these residues could occupy. By doing so, we are able to quantify a new kind of invariance beyond the apparent variations in protein families, namely, the conservation of the physical space available at structurally equivalent positions for side-chain packing. Corresponding positions in native structures are likely to be of interest in protein structure prediction, protein design, and homology modeling. Visible volume is related to the degree of exposure of a residue position and to the actual rotamers in native proteins. In this article, we discuss the properties of this new measure, namely, its robustness with respect to both crystallographic uncertainties and naturally occurring variations in atomic coordinates, and the remarkable fact that it is essentially independent of the choice of the parameters used in calculating it. We also show how visible volume can be used to align protein structures, to identify structurally equivalent positions that are conserved in a family of proteins, and to single out positions in a protein that are likely to be of biological interest. These properties qualify visible volume as a powerful tool in a variety of applications, from the detailed analysis of protein structure to homology modeling, protein structural alignment, and the definition of better scoring functions for threading purposes.