全文获取类型
收费全文 | 1264796篇 |
免费 | 104884篇 |
国内免费 | 1564篇 |
专业分类
1371244篇 |
出版年
2021年 | 17692篇 |
2020年 | 12602篇 |
2019年 | 16148篇 |
2018年 | 17765篇 |
2017年 | 16592篇 |
2016年 | 28078篇 |
2015年 | 42132篇 |
2014年 | 50091篇 |
2013年 | 76349篇 |
2012年 | 33431篇 |
2011年 | 21729篇 |
2010年 | 43081篇 |
2009年 | 44672篇 |
2008年 | 20811篇 |
2007年 | 18592篇 |
2006年 | 24071篇 |
2005年 | 25600篇 |
2004年 | 24509篇 |
2003年 | 22182篇 |
2002年 | 20339篇 |
2001年 | 29043篇 |
2000年 | 26315篇 |
1999年 | 27739篇 |
1998年 | 24732篇 |
1997年 | 24478篇 |
1996年 | 24102篇 |
1995年 | 22274篇 |
1994年 | 22082篇 |
1993年 | 21124篇 |
1992年 | 24057篇 |
1991年 | 22433篇 |
1990年 | 21432篇 |
1989年 | 22315篇 |
1988年 | 20447篇 |
1987年 | 19375篇 |
1986年 | 18337篇 |
1985年 | 20515篇 |
1984年 | 20803篇 |
1983年 | 18448篇 |
1982年 | 19399篇 |
1981年 | 18865篇 |
1980年 | 17629篇 |
1979年 | 16636篇 |
1978年 | 16229篇 |
1977年 | 15718篇 |
1976年 | 15098篇 |
1975年 | 14438篇 |
1974年 | 14716篇 |
1973年 | 15197篇 |
1972年 | 12639篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
The selective action of the antibiotics chloramphenicol and cycloheximide on the synthesis of ferredoxin in liquid cultures of Chlamydomonas reinhardii was studied. Highly specific antibodies raised against Chlamydomonas ferredoxin were used to determine the in vivo synthesis of apoferredoxin and conversion into native protein. The results indicate that 80S ribosomes are involved in the synthesis. Chlamydomonas cells growing in the absence of iron did not synthesize immunologically detectable amounts of ferredoxin. We suggest that this is based upon feed-back inhibition of apoferredoxin synthesis at the translational level.Abbreviations CAP
chloramphenicol
- CHI
cycloheximide
- IgG
Immunoglobulin G
- PBS
140.4 mM NaCl. 9 mM Na2HPO4, 1.3 mM NaH2PO4 (pH 74)
- SDS
sodium dodecvl sulphate
- Fd
Ferredoxin
- apoFd
Apoferredoxin
- CM-Fd
Scarboxymethylated Fd
- TCA-Fd
Fd treated with trichloroacetic acid 相似文献
192.
An isoleucine arrest point in G1 was determined by two methods for CHO and 3T3 cells. In the first method the fraction of cells entering S after isoleucine deprivation was assessed by [3H]thymidine labelling and autoradiography. In the second method cells entering S after isoleucine deprivation were identified by double-label autoradiography using [3H] and [14C]thymidine. From the fraction of cells entering S, determined by the two methods, the arrest point in G1 (and entry into G0) is located within the last 40 min of G1. 相似文献
193.
194.
Conditions for breaking various medically important yeasts using glass beads, 30 ml Corex centrifuge tubes, and a Vortex mixer were determined. From 75–95% ofCandida hyphal cells and all species of yeasts exceptSporothrix schenckii were broken when 10 g of 0.45–0.50 mm glass beads, 50–300 mg of wet cells in 5 ml of buffer, and 90 s of vortexing were employed. Yeasts ofSporothrix schenckii broke more efficiently when 0.25–0.30 mm beads were used. 相似文献
195.
196.
V. Luu-The J. Cumps P. Dumont 《Biochemical and biophysical research communications》1980,93(3):776-781
Using homogeneous cytochrome P-450, we have shown that the well-known metyrapone-dithionite reduced cytochrome P-450 complex is specific for the cytochrome P-450b induced by phenobarbital. A linear relationship was observed between the absorbance of metyrapone-reduced cytochrome P-450 complex and the one of CO-reduced cytochrome P-450 complex, the usual method for the determination of cytochrome P-450. A method has been proposed for the specific determination of the cytochrome P-450b. 相似文献
197.
198.
199.
200.