全文获取类型
收费全文 | 1010篇 |
免费 | 97篇 |
出版年
2021年 | 9篇 |
2018年 | 11篇 |
2016年 | 19篇 |
2015年 | 23篇 |
2014年 | 25篇 |
2013年 | 56篇 |
2012年 | 48篇 |
2011年 | 39篇 |
2010年 | 20篇 |
2009年 | 27篇 |
2008年 | 41篇 |
2007年 | 58篇 |
2006年 | 26篇 |
2005年 | 37篇 |
2004年 | 29篇 |
2003年 | 44篇 |
2002年 | 44篇 |
2001年 | 17篇 |
2000年 | 11篇 |
1999年 | 15篇 |
1997年 | 16篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 14篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 18篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1976年 | 14篇 |
1975年 | 16篇 |
1974年 | 13篇 |
1973年 | 14篇 |
1972年 | 20篇 |
1971年 | 19篇 |
1970年 | 15篇 |
1969年 | 10篇 |
1968年 | 18篇 |
1967年 | 10篇 |
1966年 | 7篇 |
排序方式: 共有1107条查询结果,搜索用时 15 毫秒
1.
Vernon Shattuck Frank R. Katterman 《Biochemical and biophysical research communications》1982,109(3):1017-1025
When cotyledonary tissue of cotton are treated with the mutagen ethyl methanesulfonate and then germinated, an enhanced, unscheduled DNA synthesis response is observed, along with a concomitant increase in the thymidine triphosphate precursor pool size. The implications of these results are discussed in this paper. 相似文献
2.
3.
In an ultrastructural study of the hepatopancreas of Porcellio scaber, an obligate intracellular parasite, Chlamydia, was noted in the epithelial cells. Although the infection was found to extend the entire length of the hepatopancreas, it was most extensive in the glandular region. Indirect immunofluorescence testing revealed no cross-reactivity with either lymphogranuloma venereum or psittacosis antisera. 相似文献
4.
Reverse-phase high-performance liquid chromatography was used to analyse the products of treatment of mouse nerve growth factor with cyanogen bromide followed by trypsin as described by Mercanti et al. All the biological activity was found to be due to incompletely cleaved starting material. Total digestion with trypsin led to complete loss of activity. 相似文献
5.
6.
Protein synthesis was measured in vivo in the whole body and in a number of individual tissues in mice at various stages of pregnancy and lactation. The absolute rate of protein synthesis in the whole body increased from 640 mg/day in virgin mice to 1590 mg/day by day 18 of pregnancy, and to 2100 mg/day by day 15 of lactation. Large proportions of these increments were contributed by the rapidly growing foetuses and placentae in the pregnant animals and by protein synthesis in the mammary glands during lactation. In addition, a substantial stimulation of growth and protein synthesis was also observed in the liver and the gastrointestinal tract. Gastrocnemius muscle showed no changes in protein metabolism, indicating that in the well-fed mouse this tissue is not required to play a role as a protein reserve during pregnancy and lactation. 相似文献
7.
8.
A small basic peptide with an unusual amino acid composition has been isolated from the seeds of pumpkin, Cucurbita maxima. Amino acid analysis and sequence data show the protein to be about 36 residues in length, with an approximate composition Lys1, Arg14, Asp3, (Glu + Gln)15, Gly1, Pro1, Trp1. On the basis of composition, the molecular weight is approximately 5000 daltons and the nitrogen content by weight is 20.4%. Twelve amino acids are entirely lacking. The peptide is slightly toxic to mouse B-16 melanoma cells, but its in vivo function is unknown. It does not appear to be derived from cucurbitin, the pumpkin storage globulin; however, it could be a storage peptide involved in nitrogen mobilization during the early stages of germination. 相似文献
9.