全文获取类型
收费全文 | 3841篇 |
免费 | 311篇 |
国内免费 | 6篇 |
出版年
2023年 | 28篇 |
2022年 | 72篇 |
2021年 | 116篇 |
2020年 | 76篇 |
2019年 | 94篇 |
2018年 | 81篇 |
2017年 | 84篇 |
2016年 | 114篇 |
2015年 | 181篇 |
2014年 | 200篇 |
2013年 | 248篇 |
2012年 | 296篇 |
2011年 | 304篇 |
2010年 | 187篇 |
2009年 | 147篇 |
2008年 | 218篇 |
2007年 | 190篇 |
2006年 | 170篇 |
2005年 | 161篇 |
2004年 | 135篇 |
2003年 | 140篇 |
2002年 | 113篇 |
2001年 | 41篇 |
2000年 | 30篇 |
1999年 | 43篇 |
1998年 | 34篇 |
1997年 | 26篇 |
1996年 | 24篇 |
1995年 | 25篇 |
1994年 | 19篇 |
1993年 | 22篇 |
1992年 | 12篇 |
1991年 | 18篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 22篇 |
1987年 | 15篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 34篇 |
1981年 | 22篇 |
1980年 | 23篇 |
1979年 | 24篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1973年 | 17篇 |
1972年 | 16篇 |
1971年 | 16篇 |
排序方式: 共有4158条查询结果,搜索用时 15 毫秒
21.
Ribonucleic Acid Synthesis of Vesicular Stomatitis Virus: I. Species of Ribonucleic Acid Found in Chinese Hamster Ovary Cells Infected with Plaque-forming and Defective Particles 总被引:62,自引:50,他引:12
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Plaque-forming B particles of vesicular stomatitis virus (VSV) induce the synthesis of virus-specific ribonucleic acid (RNA) in Chinese hamster ovary cells, whereas defective T particles do not. Infection with low input multiplicities of B results in the formation of four species of RNA. During infection with high multiplicities, RNA synthesis begins with mainly these four species of RNA but gradually shifts to a new pattern of RNA synthesis involving five other species of RNA. The change can also be induced by superinfection with T at 2.5 hr after infection with a low multiplicity of B. T added at the same time as B prevents virtually all RNA synthesis. Synthesis of the first group of RNA species correlates with the formation of B particles, whereas synthesis of the second group correlates with the formation of T particles. The various species of RNA formed after infection with VSV particles include single-stranded RNA, a completely double-stranded RNA, and RNA with partially double-stranded regions. These observations begin to establish a molecular basis for understanding the ability of T particles to interfere with the growth of B particles. 相似文献
22.
The rapid fluorescent-antibody staining technique described by Kellogg and Deacon for staining Neisseria gonorrhoeae and Treponema pallidum was applied to fluorescent-antibody tests for group A streptococci and enteropathogenic Escherichia coli. Results obtained with this staining technique were compared with results using the conventional staining procedure; excellent correlation was obtained. Considerable time and materials were saved by using the rapid method; it was also found completely satisfactory. 相似文献
23.
24.
25.
The incorporation of uridine into RNA in brain slices was studied. Optimal conditions for uridine incorporation were determined. The characteristics of the product suggest that de novo DNA-directcd synthesis of fairly high molecular weight material takes place. Incorporation into RNA of several areas of brain was studied. The incorporation was also studied as a function of the age of the animal. Finally, an apparent correlation was observed between the decrease in uridine incorporation with age and the increase of the enzyme uridine nucleosidase which hydrolyses uridine to uracil, a material which cannot be incorporated into RNA. 相似文献
26.
The Photosynthetic Electron Transport Chain of Chlamydomonas reinhardi. VII. Photosynthetic Phosphorylation by a Mutant Strain of Chlamydomonas reinhardi Deficient in Active P700 总被引:7,自引:5,他引:2
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Electron transport activity and absorbance changes associated with P700 were investigated in a mutant strain of Chlamydomonas reinhardi with impaired photosynthesis. This mutant strain, ac-8oa, cannot reduce NADP with electrons from either water or dye and ascorbate, but it has considerable Hill activity. The mutant strain shows none of the absorbance changes characteristic of P700. Although unable to carry out cyclic photosynthetic phosphorylation, ac-8oa is able to synthesize ATP when ferricyanide is provided as an electron acceptor.
These observations lead to the conclusion that a site for the coupling of photosynthetic phosphorylation with electron transport must exist between the 2 photochemical systems.
相似文献27.
28.
Alice K. Strangway 《CMAJ》1960,83(20):1040-1046
29.
Alice Stewart 《BMJ (Clinical research ed.)》1960,2(5209):1381-1382
30.