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881.
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883.
The opsonization and lysis of different protozoa by antibodies and/or complement was followed using luminol-dependent chemiluminescence and bioluminescence. The addition of immune serum to variable antigen type populations of Trypanosoma evansi led to the specific opsonization of trypanosomes resulting in an intense metabolic activation and chemiluminescence response of phagocytic cells. In comparison to those of uninfected control mice, the phagocytosis of coccidia merozoites by spleen cells from mice infected with Eimeria falciformis was enhanced during the acute stage of a primary infection. Opsonizing activity was demonstrated in phosphate-buffered saline extracts of gut contents of mice infected for 10 days. The incubation of E. falciformis merozoites together with guinea-pig complement resulted in slow lysis of the cells. The addition of mouse serum collected greater than 6 days after an infection led to an accelerated lysis of the merozoites, indicating the appearance of complement-fixing antibodies in the serum. Heat-inactivated immune serum alone had no lysing activity on merozoites. In the presence of complement, bovine lymphoblastoid cells infected with Theileria annulata were lysed by anti-lymphoblastoid cell serum raised in mice but not by serum from cattle which had developed immunity to Theileria annulata. 相似文献
884.
Bendimerad N Taleb Bendiab SA Benabadji AB Fernandez X Valette L Lizzani-Cuvelier L 《Journal of agricultural and food chemistry》2005,53(8):2947-2952
The essential oil composition of an endemic Algerian Cruciferae, Pseudocytisus integrifolius (Salisb.) Rehder, was analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). Eighty-three components representing more than 96.5% of the oil were identified. The major components were dimethyl disulfide (33.4%), dimethyl trisulfide (24.2%), and an unsaturated nitrile (31.7%). Fractionation on a silica gel column led to the identification of trace-level compounds, in particular, polar compounds such as nitriles and aldehydes, and to the isolation of dimethyl disulfide, dimethyl trisulfide, and an unsaturated nitrile. Structural analysis using high-resolution mass spectrometry (HRMS) and 1H,13C NMR techniques enabled the identification of pent-4-enenitrile. Variation in essential oil composition and yields was studied according to harvesting time, drying, and parts of the plant. The essential oil of aerial parts was tested for its antibacterial activity using a paper disk method. The oil was effective on the inactivation of Escherichia coli and Pseudomonas aeruginosa and ineffective on the inactivation of Staphylococcus aureus. 相似文献
885.
Fazel R. Sadeque Ahmed Ian J. Alexander Mwinyikione Mwinyihija Kenneth Killham 《Water, air, and soil pollution》2011,221(1-4):169-182
Arsenic (As)-contaminated irrigation water is responsible for high As levels in soils and crops in many parts of the world, particularly in the Bengal Delta, Bangladesh and West Bengal, India. While arbuscular mycorrhizal (AM) fungi markedly improve phosphorus (P) uptake, they can also alleviate metal toxicity. In this study, the effects of superphosphate and inoculation with the AM fungus Glomus mosseae on P and As uptake of lentil were investigated. Plant height, shoot dry weight, shoot/root P concentration, and shoot P content increased due to mycorrhizal inoculation. However, As concentration in roots/shoots and root As content were reduced, plant height, shoot dry weight, shoot/root P concentration/content, and root As concentration and content increased due to superphosphate application. Root P concentration decreased with increasing As concentration. It was apparent that As concentration and content in shoots/roots increased with increasing As concentration in irrigation water. Superphosphate interaction with G. mosseae reduced the role of mycorrhizal infection in terms of enhancing P nutrition and reducing uptake of potentially toxic As into plant parts. The role and relationship of mycorrhizal in respect of P nutrition and As remediation efficiency in plant parts was established. In conclusion, it was worth alluding to that lentil with AM fungal inoculation can reduce As uptake and improve P nutrition. However, in retrospect superphosphate increased P and As uptake and decreased the role of the mycorrhizal association. This resulted in stimulating increased P uptake while decreasing As uptake in lentil. 相似文献
886.
Seayad A Ahmed M Klein H Jackstell R Gross T Beller M 《Science (New York, N.Y.)》2002,297(5587):1676-1678
The selective synthesis of linear amines from internal olefins or olefin mixtures was achieved through a catalytic one-pot reaction consisting of an initial olefin isomerization followed by hydroformylation and reductive amination. Key to the success is the use of specially designed phosphine ligands in the presence of rhodium catalysts. This reaction constitutes an economically attractive and environmentally favorable synthesis of linear aliphatic amines. 相似文献
887.
888.
Lahori Altaf Hussain Vu Ngoc Ha Du Juan Dinh Quang Toan Saif-Ur-Rehman Naheed Zobia Ahmed Muneer Zhang Zengqiang 《Journal of Soils and Sediments》2020,20(2):734-744
Journal of Soils and Sediments - Mine and smelter soil contaminations with Pb, Cu, Cd, and Zn have become serious problems in China, because of anthropogenic activities. Little is known about the... 相似文献
889.
Salinity reduced (reduction below control = RBC) grain yield of rice by 80 and 98% at 8 and 16 mS/cm levels of saline irrigation, respectively, below tap water (0.6 mS/cm). The adverse effect of salinity was more pronounced on grain yield (98% RBC at 16 mS/cm) than on straw yield (84% RBC). The combined application of gypsum and Zn at the rates of 160 and 5 kg/ha produced 49, 45, and 41% more grain yield above controls at 0.6, 8, and 16 mS/cm levels of salinity, respectively. The length of panicles, percentage of filled grains, and 1000-grain weight, protein concentrations of the rice grains, sum of Ca, Mg and K concentrations were reduced due to imposition of saline irrigation, but gypsum and Zn treatments significantly improved these parameters even at the highest (16 mS/cm) salinity stress. The combined application of gypsum and Zn was found to be effective to increase the protein concentrations in rice grains by 2–4% and to increase total concentrations of Ca, Mg and K, but reduced the Na/K ratios in plant tissues by 29.13, and 12% at 0.6, 8, and 16 mS/cm salinity, respectively, suggesting that the application of gypsum and Zn in parallel with irrigation of saline soils, would be effective to reduce the adverse effects of high Na/K ratios as well as to improve growth, yield, and nutritional balance in rice. 相似文献
890.
The fragmentation of one synthetic and four soil humic acids was studied in solutions of sodium hydroxide (pH 13) at different temperature between 0 and 90°C. The dissolved parts of the initial amounts of humic acids decreased to a minimum with the increase in temperature from 0 to 10°C. The fragmentation in this region was a function of both; temperature and concentration. At 15–20°C all of the initial amounts of humic acids were dissolved. The rate of fragmentation increased rapidly between 15 and 20°C and later slowed down between 20 and 40°C. This was due to the reaggregation of the particles of the produced hymatomelanic acids into particles of similar solubilities as those of the residual nonfragmented parts of the humic acids. This reaggregation took place probably through the formation of hydrophobic bonds. The fragmentation increased at temperatures above 40°C, and reached a maximum between 50 and 70°C depending on the type of the humic acid. The decline in fragmentation at temperatures higher than those corresponding to the maxima is most probably due to chemical reactions, in which the fragmentation products especially fulvic acids recombine together at about 60°C. Importance of these results in analytical methods of extraction and characterisation of humic acids is discussed. 相似文献