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排序方式: 共有466条查询结果,搜索用时 78 毫秒
461.
Strano MS Dyke CA Usrey ML Barone PW Allen MJ Shan H Kittrell C Hauge RH Tour JM Smalley RE 《Science (New York, N.Y.)》2003,301(5639):1519-1522
Diazonium reagents functionalize single-walled carbon nanotubes suspended in aqueous solution with high selectivity and enable manipulation according to electronic structure. For example, metallic species are shown to react to the near exclusion of semiconducting nanotubes under controlled conditions. Selectivity is dictated by the availability of electrons near the Fermi level to stabilize a charge-transfer transition state preceding bond formation. The chemistry can be reversed by using a thermal treatment that restores the pristine electronic structure of the nanotube. 相似文献
462.
Wilson Tamara S. Matchett Elliott Byrd Kristin B. Conlisk Erin Reiter Matthew E. Wallace Cynthia Flint Lorraine E. Flint Alan L. Joyce Brian Moritsch Monica M. 《Landscape Ecology》2022,37(3):861-881
Landscape Ecology - California’s Central Valley provides critical habitat for migratory waterbirds, yet only 10% of naturally occurring wetlands remain. Competition for limited water supplies... 相似文献
463.
Rosa A Atzeri A Deiana M Melis MP Incani A Corona G Loru D Appendino G Dessì MA 《Journal of agricultural and food chemistry》2008,56(10):3546-3553
This study investigated the effect of synthetic capsiate, a simplified analogue of capsiate, and vanillyl alcohol on the oxidative stress induced by tert-butyl hydroperoxide (TBH) in a line of fibroblasts derived from monkey kidney (Vero cells). In response to the TBH-mediated oxidative stress, a reduction of the levels of total unsaturated fatty acids and cholesterol was observed, and a rise in the concentrations of conjugated dienes fatty acids hydroperoxides and 7-ketocholesterol. Pretreatment with both synthetic capsiate and vanillyl alcohol preserved Vero cells from oxidative damage and showed a remarkable protective effect on the reduction of the levels of total unsaturated fatty acids and cholesterol, inhibiting the increase of MDA, conjugated dienes fatty acids hydroperoxides, and 7-ketocholesterol. Both compounds were effective against peroxidation of cell membrane lipids induced by TBH, with synthetic capsiate essentially acting as a pro-drug of vanillyl alcohol, its hydrophilic hydrolytic derivative. 相似文献
464.
Giuseppe Colla Youssef Rouphael Mariateresa Cardarelli Monica Tullio Carlos Mario Rivera Elvira Rea 《Biology and Fertility of Soils》2008,44(3):501-509
With the aim of determining whether the arbuscular mycorrhizal (AM) inoculation would give an advantage to overcome salinity
problems and if the phosphorus (P) concentration can profoundly influence zucchini (Cucurbita pepo L.) plant responses to AM, a greenhouse experiment was carried out with AM (+AM) and non-AM (−AM). Plants were grown in sand
culture with two levels of salinity (1 and 35 mM NaCl, giving electrical conductivity values of 1.8 and 5.0 dS m−1) and P (0.3 and 1 mM P) concentrations. The percentages of marketable yield and shoot biomass reduction caused by salinity
were significantly lower in the plants grown at 0.3 mM P, compared to those grown at 1 mM P. However, even at high P concentration,
the absolute value of yield and shoot biomass of +AM zucchini plants grown under saline conditions was higher than those grown
at low P concentration. The +AM plants under saline conditions had higher leaf chlorophyll content and relative water content
than −AM. Mycorrhizal zucchini plants grown under saline conditions had a higher concentration of K and lower Na concentration
in leaf tissue compared to −AM plants. The P content of zucchini leaf tissue was similar for +AM and −AM treatments at both
low and high P concentrations in the saline nutrient solution. The beneficial effects of AM on zucchini plants could be due
to an improvement in water and nutritional status (high K and low Na accumulation). 相似文献
465.
Sanden M Stubhaug I Berntssen MH Lie Ø Torstensen BE 《Journal of agricultural and food chemistry》2011,59(23):12697-12706
The objective of the present study was to investigate the effects of replacing high levels of marine ingredients with vegetable raw materials and with emphasis on lipid metabolism and net production of long-chain polyunsaturated ω-3 fatty acids (EPA + DHA). Atlantic salmon were fed three different replacement vegetable diets and one control marine diet before sensory attributes, β-oxidation capacity, and fatty acid productive value (FAPV) of ingested fatty acids (FAs) were evaluated. Fish fed the high replacement diet had a net production of 0.8 g of DHA and a FAPV of 142%. Fish fed the marine diet had a net loss of DHA. The present work shows that Atlantic salmon can be a net producer of marine DHA when dietary fish oil is replaced by vegetable oil with minor effects on sensory attributes and lipid metabolism. 相似文献
466.
Farinacci M Colitti M Sgorlon S Stefanon B 《Veterinary immunology and immunopathology》2008,126(1-2):54-63
Neutrophils play an essential role in host defense and inflammation. Plants have long been used to improve the immune function, but for most of them specific investigations on animal health are lacking. In the present study, water and hydroethanolic extracts from 11 plant wastes have been screened on immune responses of ovine neutrophils. Eight sheep clinically healthy, not lactating, non-pregnant were selected and used for the experiment. Freshly isolated neutrophils were incubated with the extracts of the residues at increasing doses, and then they were tested for adhesion and superoxide production induced with PMA. The residues of Larix decidua, Thymus vulgaris, Salix alba, Sinupret, Helianthus annuus, Mangifera indica modulated the neutrophil immune functions, moreover, Larix decidua, Thymus vulgaris and Salix alba presented the highest anti-inflammatory activity. 相似文献