全文获取类型
收费全文 | 280篇 |
免费 | 13篇 |
出版年
2022年 | 1篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 12篇 |
2015年 | 21篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 16篇 |
2011年 | 7篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 7篇 |
2007年 | 15篇 |
2006年 | 9篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有293条查询结果,搜索用时 31 毫秒
1.
Cecilia PC Soh Alastair SR Donald James Feeney Walter TJ Morgan Winifred M Watkins 《Glycoconjugate journal》1989,6(3):319-332
The tetrasaccharides GalNAcß1-4[NeuAc2-3]Galß1-4Glc and GalNAcß1-4[NeuAc2-3]Galß1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3-sialyllactose (NeuAc2-3Galß1-4Glc) and 3-sialyl-N-acetyllactosamine (NeuAc2-3Galß1-4GlcNAc). The structures of the products were established by methylation and1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3-sialyl-N-acetyllactosamine was highly active whereas that formed with 3-sialyllactose had only weak activity. 相似文献
2.
3.
Nuclear Overhauser effect and computational characterization of the beta-spiral of the polypentapeptide of elastin 总被引:1,自引:0,他引:1
D K Chang C M Venkatachalam K U Prasad D W Urry 《Journal of biomolecular structure & dynamics》1989,6(5):851-858
The structure of the elastin polypentapeptide, poly(VPGVG), was studied by nuclear Overhauser effect experiments using perdeuterated Val1 and Val4 samples under the condition where intermolecular interactions are absent. More extensive interaction was found between the Val1 gamma CH and Pro2 beta CH protons than between the Val4 gamma CH and Pro2 beta CH protons. The Val1 gamma CH3-Pro2 beta CH interaction does not occur within the same pentamer as previously shown experimentally and as expected from steric considerations. The results are incompatible with the presence of a random chain network in poly(VPGVG) at room temperature but are readily explicable in terms of interturn interactions in a beta-spiral structure. More specifically, the results indicate that the beta-spiral conformation with 2.9 pentamers/turn is more prevalent than that with 2.7 pentamers/turn. Using conformations developed by molecular mechanics calculations, molecular dynamics simulations were carried out to compare the relative energies of these two variants of this class of beta-spiral structures. It was found in vacuo that the structure with 2.9 pentamers/turn is indeed more stable than that of 2.7 pentamers/turn by approximately 1 kcal/mole-pentamer. 相似文献
4.
Approaches to breeding for salinity tolerance - a case study on Porteresia coarctata 总被引:2,自引:0,他引:2
R LATHA C SRINIVAS RAO H M SR SUBRAMANIAM P EGANATHAN M S SWAMINATHAN 《The Annals of applied biology》2004,144(2):177-184
Cereals are the world's major source of food for human nutrition. Among these, rice (Oryza sativa) is the most prominent and represents the staple diet for more than two-fifths (2.4 billion) of the world's population, making it the most important food crop of the developing world (Anon., 2000a). Rice production in vast stretches of coastal areas is hampered due to high soil salinity. This is because rice is a glycophyte and it does not grow well under saline conditions. In order to increase rice production in these areas there is a need to develop rice varieties suited to saline environments. Research has shown that Porteresia coarctata, a highly salt tolerant wild relative of rice growing in estuarine soils, is an important material for transferring salt tolerant characteristics to rice. It is quite possible that Porteresia may be used as a parent for evolving better and truly salt resistant varieties. The inadequate results and the difficulties associated with conventional breeding techniques necessitate the use of the tools of crop biotechnology in unravelling some of the characteristics of Porteresia that have been highlighted in this report. In view of the limited resources available for increasing salinity tolerance to the breeders to wild rice germplasm, Porteresia is undoubtedly one of the key source species for elevating salinity tolerance in cultivated rice. 相似文献
5.
6.
The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs. 相似文献
7.
Semi-empirical energy calculations for an internal Pro-Pro dimer are presented that take into account the nature of the flexibility of the proline ring due to its puckering. Calculations show that three stable conformations are available for the dimer: the cis (ω = 0°, ψ = 160°); the trans (ω = 180°, ψ = 160°, also referred to as trans′); and the cis′ (ω = 180°, ψ = ?40°) conformations. The best conformational pathways between these stable conformations are determined. Calculations also show that the barrier for cis′–trans′ conversion is of the same order of magnitude as that for cis–trans conversion. 相似文献
8.
9.
Zhang Guanshi Zhang Jialing DeHoog Rachel J. Pennathur Subramaniam Anderton Christopher R. Venkatachalam Manjeri A. Alexandrov Theodore Eberlin Livia S. Sharma Kumar 《Metabolomics : Official journal of the Metabolomic Society》2020,16(1):1-12
Metabolomics - Food and dietary ingredients have significant effects on metabolism and health. To evaluate whether and how different diets affected the serum lipidomic profile of dogs. Sixteen... 相似文献
10.
Mandal Anup Mani Anjali Kottayil Lamech Ruban Anandajothi Elamaran Venkatachalam Shanmuga Arasu Dinakaran Gajendiran K. Quinitio Emilia T. Kandan Shanmuganathan 《Biochemical genetics》2021,59(4):856-869
Biochemical Genetics - Misleading identification and subsequent publications on biological, molecular, and aquaculture data of mangrove mud crab (genus Scylla de Hann 1833) is a major concern in... 相似文献