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1.
Fast pyrolyses of sewage sludge (SS), pig compost (PC), and wood chip (WC) were investigated in an internally circulating fluidized-bed to evaluate bio-oil production. The pyrolyses were performed at 500 °C and the bio-oil yields from SS, PC, and WC were 45.2%, 44.4%, and 39.7% (dried and ash-free basis), respectively. The bio-oils were analyzed with an elemental analyzer, Karl-Fischer moisture titrator, bomb calorimeter, Fourier transformation infrared spectrometer, gel permeation chromatograph, and gas chromatography/mass spectrometry. The results show that the bio-oil from SS is rich in aliphatic and organonitrogen species, while the bio-oil from PC exhibits higher caloric value due to its higher carbon content and lower oxygen content in comparison with that from SS. The bio-oils from SS and PC have similar chemical composition of organonitrogen species. Most of the compounds detected in the bio-oil from WC are organooxygen species. Because of its high oxygen content, low H/C ratio, and caloric value, the bio-oil from WC is unfeasible for use as fuel feedstock, but possible for use as chemical feedstock.  相似文献   

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Summary Forty-one strains of non-sporulating sulfate-reducing bacteria were isolated from estuaries, deep sea and other saline environments. Their salinity requirements, utilization of significant carbon compounds, resistance against growth inhibition by Hibitane, optimal growth temperatures and growth temperature ranges were studied. The results include data on strains isolated from the Red Sea hot brine deep area. Basing on the determined characteristics the strains were identified as Desulfovibrio desulfuricans, D. vulgaris, D. salexigens, and D. desulfuricans var. aestuarii.  相似文献   

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Heparan sulfate (HS), is a proteoglycan (PG) found both in the extracellular matrix and on cell surface. It may represent one of the most biologically important glycoconjugates, playing an essential role in a variety of different events at molecular level. The publication of the mouse genome, and the intensive investigations aimed at understanding the proteome it encodes, has motivated us to initiate studies in mouse glycomics focused on HS. The current study is aimed at determining the quantitative and qualitative organ distribution of HS in mice. HS from brain, eyes, heart, lung, liver, kidney, spleen, intestine and skin was purified from 6–8 week old male and female mice. The recovered yield of HS from these organs is compared with the recovered whole body yield of HS. Structural characterization of the resulting HS relied on disaccharide analysis and 1H-NMR spectroscopy. Different organs revealed a characteristic HS structure. These data begin to provide a structural understanding of the role of HS in cell-cell interactions, cell signaling and sub-cellular protein trafficking as well as a fundamental understanding of certain aspects of protein-carbohydrate interactions.  相似文献   

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Partial N-desulfation of beef-lung heparin prior to degradative deamination with butyl nitrite and reduction with sodium borotritide yielded many large fragments. From these, a tetrasaccharide tetra-O-sulfate (II-4NH; 8% yield from heparin) and a mixture of tetrasaccharide tri-O-sulfates (II-3NHh; 6% yield) were isolated by sequential chromatography on Sephadex G-25 and DEAE-Sephadex. For these and the other tetrasaccharide preparations, the radioactive disaccharides produced by deamination, with and without subsequent relabelling with sodium borotritide, have been quantitatively determined by the methodology described in the preceding paper. In most cases, the results permit a unique reconstruction of the relative proportions of monosaccharide components and of their sequences in the compounds present. Tetrasaccharide II-4NH appeared homogeneous and has the structure (IdoA-SO4)(GN-O-SO4)(IdoA-SO4)(anhMan-SO4). In tetrasaccharide preparation II-3NHh, the preponderant species (57%) lacks ester sulfate at the terminal l-iduronic residue in the structure just mentioned, and five other species are present. By treatment of the tetra-O-sulfate with mild acid, tetrasaccharide preparations with 3, 2, 1, and no ester sulfate were produced and could be isolated. The isomeric tetrasaccharide tri-O-sulfate species have been partially resolved. Composition and sequence data are given for all of the preparations. The resolution of numerous small fractions suggests minor irregularities in the fine structure of heparin. Ion-exchange electrophoresis was applied to the acidic oligosaccharides and was found to be a useful technique.  相似文献   

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Extensive studies of humoral and cell mediated autoimmune responses to thyroid antigens have been performed in order to understand the underlying mechanisms of autoimmune thyroid disorders. Very little is known, however, about the nature of the lymphocyte subpopulations in the thyroid gland and their possible involvement in the pathogenesis of thyroid diseases. We have developed a Percoll gradient technique to separate mononuclear cells from thyroid cells of resected thyroid glands. Thyroid tissue was minced, incubated with Dispase and passed through a tissue sieve. The filtrate was layered onto a four step discontinuous Percoll gradient (densities 1.140, 1.077, 1.061, 1.030 g/ml). Thyroid cells appeared in band II and mononuclear cells in band III. Mononuclear cells were characterized using the monoclonal antibodies OKT-3, OKT-8, OKI-a and OKM-1, and the levels of these populations in peripheral blood and thyroid tissue compared. Patients have been classified by conventional clinical, immunological and histological criteria. The studies involved thyroid tissues from 8 patients with euthyroid nodular goitre, 7 patients with Graves' disease and 1 with Hashimoto's thyroiditis. In the thyroid tissue of non-autoimmune thyroid diseases we find significantly less OKT-3+ cells compared to peripheral blood. In thyroid tissue of autoimmune thyroid diseases there are significantly less OKT-8+ cells compared to peripheral blood. These preliminary results might be linked to the hypothesis of decreased suppressor T-cell activity in autoimmune thyroid disease.  相似文献   

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A method for the isolation of reactivated chick erythrocyte nuclei from heterokaryons was developed. The heterokaryons were produced by fusing chick erythrocytes with HeLa or L cells in the presence of inactivated Sendai virus. At various time intervals after fusion nuclei were isolated directly from the monolayer by treatment with an acidic detergent solution. Chick erythrocyte nuclei were then separated from other nuclei (HeLa or L cell) by centrifugation on sucrose gradients. The purified preparation of reactivated chick erythrocyte nuclei was shown to be free from other nuclei and cytoplasmic contamination. By using L cells which had been labelled with 3H-leucine before fusion or heterokaryons labelled after fusion it was demonstrated that labelled mouse proteins migrate from the cytoplasm of the heterokaryons into the reactivating chick erythrocyte nuclei. 3H-uridine labelling of heterokaryons made by fusing UV-irradiated chick erythrocytes with L cells failed to reveal any significant migration of mouse RNA into the chick erythrocyte nuclei.  相似文献   

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Preparation and characterization of activated carbon from rice bran   总被引:1,自引:0,他引:1  
A study on the preparation of rice bran-based activated carbon was conducted, with and without an acid treatment step prior the activation process. The influence of the activation time on the structure of the activated carbons was evaluated. The acid treatment had a significant positive influence on sorption properties. The rice bran-activated carbon presented a BET surface area of 652m(2)g(-1) and a pore volume of 0.137cm(3)g(-1), with mesopores predominance (ca. 55%). These experimental results indicated the potential use of rice bran as a precursor in the activated carbon preparation process, thus representing an economically promising material.  相似文献   

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Preparation and characterization of cellulose nanocrystals from rice straw   总被引:2,自引:0,他引:2  
Pure cellulose have been isolated from rice straw at 36% yield and hydrolyzed (64% H2SO4, 8.75 mL/g, 45 °C) for 30 and 45 min to cellulose nanocrystals (CNCs), i.e., CNC30 and CNC45, respectively. CNC45 was smaller (11.2 nm wide, 5.06 nm thick and 117 nm long) than CNC30 (30.7 nm wide, 5.95 nm thick and 270 nm long). Freeze-drying of diluted CNC suspensions showed both assembled into long fibrous structures: ultra-fine fibers (∼400 nm wide) from CNC45 and 1-2 μm wide broad ribbons interspersed with CNC clusters from CNC30. The self-assembled fibers from CNC30 and CNC45 were more highly crystalline (86.0% and 91.2%, respectively) and contained larger crystallites (7.36 nm and 8.33 nm, respectively) than rice straw cellulose (61.8%, 4.42 nm). These self-assembled fibers had essentially nonporous or macroporous structures with the CNCs well aligned along the fiber axis. Furthermore, the self-assembled ultra-fine fibers showed extraordinary structural stability, withstanding vigorous shaking and prolong stirring in water.  相似文献   

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A protocol for the isolation of functional thylakoids from Arabidopsis thaliana leaves was developed. The critical factor in obtaining active, coupled and stable preparation is the inclusion of EDTA and EGTA in the grinding buffer. Preparations were characterized with respect to the whole or partial electron transport chain, ATP/NADPH, ATP/O2 and PS II/chlorophyll ratios. Sensitivity to a light-chill photoinhibitory treatment was also determined by evaluating the decrease in both maximal photochemical efficiency (Fv/Fm) and in electron transport rate. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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We have developed a reliable procedure for the purification of envelope membranes from cauliflower (Brassica oleracea L.) bud plastids and sycamore (Acer pseudoplatanus L.) cell amyloplasts. After disruption of purified intact plastids, separation of envelope membranes was achieved by centrifugation on a linear sucrose gradient. A membrane fraction, having a density of 1.122 grams per cubic centimeter and containing carotenoids, was identified as the plastid envelope by the presence of monogalactosyldiacylglycerol synthase. Using antibodies raised against spinach chloroplast envelope polypeptides E24 and E30, we have demonstrated that both the outer and the inner envelope membranes were present in this envelope fraction. The major polypeptide in the envelope fractions from sycamore and cauliflower plastids was identified immunologically as the phosphate translocator. In the envelope membranes from cauliflower and sycamore plastids, the major glycerolipids were monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and phosphatidylcholine. Purified envelope membranes from cauliflower bud plastids and sycamore amyloplasts also contained a galactolipid:galactolipid galactosyltransferase, enzymes for phosphatidic acid and diacylglycerol biosynthesis, acyl-coenzyme A thioesterase, and acyl-coenzyme A synthetase. These results demonstrate that envelope membranes from nongreen plastids present a high level of homology with chloroplasts envelope membranes.  相似文献   

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D Solaiman  F Y Wu 《Biochemistry》1985,24(19):5077-5083
The Escherichia coli DNA-dependent RNA polymerase (RPase) holoenzyme (alpha 2 beta beta' sigma) possesses 2 mol equiv of Zn: beta and beta' subunits each contain one Zn ion. An in vitro metal-substitution method developed earlier (method I) was used to remove the two intrinsic Zn ions and then to reconstitute other metal ions into the beta subunit of RPase. One Cd or Hg ion was successfully reconstituted into half-active enzymes (rec-Cd1- or rec-Hg1-RPase), while Mn or Ni ion was not incorporated. A new, simplified in vitro metal-substitution method (method II), which omitted the low-pH treatment and subsequent urea dialysis in method I, was devised in this study. Consequently, Zn or Cd could be incorporated into both the beta and beta' subunits, resulting in rec-Zn2- or rec-Cd2-RPase, respectively. However, only one Hg was incorporated, probably due to steric hindrance by the large size of the Hg ion, while Mn, Ni, or Cr was not bound by the reconstituted enzyme, which instead incorporated only one Zn. Analysis of the metal content of various reconstituted RPases indicated that without low-pH treatment Zn bound to both the beta and beta' subunits when Zn concentrations were higher than 2 X 10(-6)M, but it bound only to the beta' subunit at lower concentrations. Moreover, low-pH treatment destroys the metal binding site in the beta' subunit. The metal sites on the beta and beta' subunits did not have significant affinity for the transition metals such as Mn, Ni, and Cr.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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Different elastolytic enzymes were isolated from rat aorta and platelets, as well as from granulocyte and pancreatic extracts. The active fractions were purified to electrophoretic apparent homogeneity by precipitation with ammonium sulfate, sequential batch fractionation on DEAE-Sephadex A-50, and finally by isoelectric focusing (IF) on Sephadex G-75 Superfine. The molecular weight and the isoelectric point of the isolated enzymes were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by analytical IF, respectively. All the enzymes have elastolytic activity as well as activity toward Suc-(Ala)3-NA. The inhibition profile of the different isolated enzymes toward various inhibitors indicates that aortic, pancreatic, and granulocyte enzymes all belong to the group of serine proteinases, unlike the platelet elastase which is a metalloproteinase.  相似文献   

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A procedure was developed for the large scale preparation of membranes from pig atria which are enriched 10-13 fold in the muscarinic acetylcholine receptor. The procedure involved differential centrifugation and sucrose-gradient centrifugation in solutions containing 150 mM-NaClO4 and 5 mM-EDTA to minimize membrane aggregation. The final membrane preparation bound about 1.1 pmol of L-quinuclidinyl benzilate/mg of protein. Comparable results were obtained with either fresh or frozen tissue. About the same yield (120 pmol of L-quinuclidinyl benzilate sites/100 g of tissue) and specific activity of membranes were obtained from different regions of the atria. The final preparation was stable at -80 degrees C in buffered sucrose solutions. The membranes appeared mostly as sheets or fragments and partly as closed vesicles in the electron microscope and were heterogeneous in isopycnic Percoll gradients. Marker enzyme studies showed that the receptor was enriched in parallel with the plasma membrane markers guanylate cyclase (particulate form) and (Na+ + K+)-activated ATPase. Some contamination by mitochondrial outer and endoplasmic reticulum membranes was evident from the distribution of monoamine oxidase and glucose-6-phosphatase activity, but the preparation was largely free of sarcoplasmic reticulum, mitochondrial inner, and lysosomal membranes.  相似文献   

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