全文获取类型
收费全文 | 3218篇 |
免费 | 369篇 |
国内免费 | 7篇 |
专业分类
3594篇 |
出版年
2021年 | 33篇 |
2019年 | 34篇 |
2018年 | 40篇 |
2017年 | 41篇 |
2016年 | 54篇 |
2015年 | 77篇 |
2014年 | 97篇 |
2013年 | 114篇 |
2012年 | 133篇 |
2011年 | 139篇 |
2010年 | 106篇 |
2009年 | 85篇 |
2008年 | 135篇 |
2007年 | 137篇 |
2006年 | 117篇 |
2005年 | 149篇 |
2004年 | 103篇 |
2003年 | 102篇 |
2002年 | 118篇 |
2001年 | 93篇 |
2000年 | 110篇 |
1999年 | 74篇 |
1998年 | 38篇 |
1997年 | 43篇 |
1996年 | 39篇 |
1995年 | 35篇 |
1994年 | 38篇 |
1993年 | 40篇 |
1992年 | 49篇 |
1991年 | 58篇 |
1990年 | 51篇 |
1989年 | 51篇 |
1988年 | 49篇 |
1987年 | 48篇 |
1986年 | 47篇 |
1985年 | 37篇 |
1984年 | 54篇 |
1983年 | 44篇 |
1982年 | 41篇 |
1981年 | 39篇 |
1980年 | 33篇 |
1979年 | 36篇 |
1978年 | 29篇 |
1976年 | 35篇 |
1975年 | 44篇 |
1974年 | 31篇 |
1973年 | 46篇 |
1972年 | 35篇 |
1971年 | 31篇 |
1968年 | 29篇 |
排序方式: 共有3594条查询结果,搜索用时 0 毫秒
21.
T. H. Noel Ellis Claire Domoney Judy Castleton Wendy Cleary D. Roy Davies 《Molecular & general genetics : MGG》1986,205(1):164-169
Summary We describe four genomic clones of pea 7S storage protein gene, one of which corresponds to convicilin, and the others to
vicilin. Hybridization studies exploiting these clones, and previously identified cDNA clones, have enabled us to define six
different loci. Three of these loci have been mapped to positions on chromosome 7. 相似文献
22.
Purification and properties of ribulosebisphosphate carboxylase large subunit binding protein 总被引:17,自引:4,他引:13
The large subunit binding protein, an abundant plastid protein implicated in the assembly of ribulose-1,5-bisphosphate carboxylase-oxygenase (RubisCO), has been highly purified from leaves of Pisum sativum. The 720 kilodaltons purified binding protein is composed of two types of subunits of 60 and 61 kilodaltons. Highly specific polyclonal antibodies have been raised against the binding protein. The antibodies do not cross-react with the large subunit nor do anti-RubisCO antibodies cross-react with the binding protein. A higher molecular weight form of the binding protein is immunoprecipitated from products of P. sativum polysomes translated in a wheat-germ system, indicating that the binding protein is synthesized by cytoplasmic ribosomes. Immunoblotting reveals the presence of binding protein in extracts of tobacco, wheat and barley leaves and castor bean endosperm.
The previously reported dissociation of the binding protein-large subunit complex upon addition of ATP in vitro has been confirmed and the fates of the dissociated subunits further investigated. The dissociated binding protein subunits are not phosphorylated or adenylated in vitro by added ATP.
相似文献23.
24.
To determine patterns of infant feeding and influencing factors, 131 women, interested in breastfeeding and giving birth in 1 hospital in British Columbia, Canada, were followed for 6 months postpartum. Data were collected from hospital records and each participant completed mail-in questionnaries when their babies were 1, 3 and 6 months old. At 6 months 3.9% were exclusively breastfeeding, 26.5% were feeding their infants breast milk and semisolids and 26.5% were combining breastfeeding with formula and/or semisolids. Over 50% discontinued breastfeeding before their stated intentions. Most women had chosen to breastfeed because of benefits to the baby, and most gave up breast feeding because of perceived insufficient milk. 相似文献
25.
The effect of tunicamycin, an inhibitor of N-glycosylation of proteins, on growth and on synthesis of DNA and protein was studied in suspension cultures from Nicotiana tabacum and Catharanthus rosea. In the presence of 0.1–1 g · ml-1 tunicamycin, cell division and DNA synthesis stopped in cells which had been proliferating logarithmically, but protein formation continued. Cytophotometric determination of the nuclear DNA content in Catharanthus cells showed that a cell-cycle arrest had occurred in G1 phase. Metabolic labelling of cells with the glycoprotein precursors glucosamine or mannose was inhibited, too. The results indicate that one or more glycoproteins are needed for the cell to pass through the G1 phase, as was recently postulated for animal and yeast cells.Abbreviations TCA
trichloroacetic acid
- TM
tunicamycin 相似文献
26.
27.
28.
29.
30.