全文获取类型
收费全文 | 1207篇 |
免费 | 30篇 |
专业分类
1237篇 |
出版年
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 19篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 55篇 |
2012年 | 37篇 |
2011年 | 34篇 |
2010年 | 25篇 |
2009年 | 23篇 |
2008年 | 38篇 |
2007年 | 41篇 |
2006年 | 21篇 |
2005年 | 36篇 |
2004年 | 41篇 |
2003年 | 32篇 |
2002年 | 51篇 |
2001年 | 32篇 |
2000年 | 31篇 |
1999年 | 25篇 |
1998年 | 7篇 |
1992年 | 30篇 |
1991年 | 37篇 |
1990年 | 36篇 |
1989年 | 29篇 |
1988年 | 43篇 |
1987年 | 32篇 |
1986年 | 44篇 |
1985年 | 35篇 |
1984年 | 28篇 |
1983年 | 19篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 19篇 |
1978年 | 22篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 9篇 |
1974年 | 13篇 |
1973年 | 16篇 |
1972年 | 13篇 |
1971年 | 19篇 |
1969年 | 8篇 |
1967年 | 10篇 |
1966年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有1237条查询结果,搜索用时 15 毫秒
1.
V. V. Smirnov L. N. Churkina A. N. Kravets V. I. Perepnikhatka 《Applied Biochemistry and Microbiology》2000,36(3):262-265
Various plasmids carrying transposon Tn5 were used to generate insertion mutants synthesizing batumin, a unique antibiotic
with a selective antistaphylococcal effect. One of the plasmids used provided a sufficient yield of the clones in question.
An analysis of over 7000 clones allowed us to select the mutant clones with increased and decreased levels of batumin synthesis
and the mutants that lost the ability to synthesize this antibiotic. 相似文献
2.
3.
The article reports experimental data on new bacteria, the so-called ‘stone nannobacteria’. Recent publications in Russia and abroad show that this bacterial species may cause various human ailments, thus being a serious environmental hazard. According to our findings, one of the natural habitats of nannobacteria is water which aggregates the nannobacteria-related ecological problem. 相似文献
4.
5.
6.
A N Orekhov V V Tertov D N Mukhin V E Koteliansky M A Glukhova K A Khashimov V N Smirnov 《Biochimica et biophysica acta》1987,928(3):251-258
Low-density lipoproteins (LDL) were incubated with elastin particles, collagenase-resistant debris isolated from human aorta, and latex beads of 1.13 microns in diameter. As a result of incubation, insoluble LDL-associates were formed. These associates, as well as LDL-heparin-fibronectin-gelatin complexes described by other workers, were added to a 7-day primary culture of enzyme-isolated cells of human aortic subendothelial intima. The culture contained a mixed cell population made up mostly of typical and modified smooth muscle cells. 24 h later, total cholesterol, phospholipid, triacylglycerol, free cholesterol and cholesteryl ester levels were measured. Addition of insoluble LDL-complexes as well as LDL-associates to culture brought about a substantial accumulation of intracellular lipids; primarily, cholesteryl esters. The total cholesterol level in cultured cells was raised 3- to 8-fold. Addition of free LDL or LDL-free particles had no effect on the content of intracellular lipids. The results obtained allow the assumption that the occurrence of the LDL-mediated accumulation of intracellular lipids is due mainly to the LDL penetration inside the cell via 'nonspecific' phagocytosis and not through a regulated receptor-dependent pathway. 相似文献
7.
I L Shchaveleva I P Smirnov S V Kochetkova T L Tsilevich A A Khorlin 《Bioorganicheskaia khimiia》1988,14(6):824-827
Acyclic analogues of nucleosides, viz.9- and 3-(1,6-dihydroxy-4-oxahex-3-yl)adenine, 9-(1,6-dihydroxy-4-oxahex-3-yl)guanine, 1-(1,6-dihydroxy-4-oxahex-3-yl)cytosine and thymine, with C3'-C4' bond of the furanose ring cleaved, have been prepared by condensation of trimethylsilyl derivatives of nucleic acid bases with 1,4,6-triacetoxy-3-oxahexane in the presence of Lewis acids followed by treatment with metanolic ammonia. 相似文献
8.
I P Smirnov S V Kochetkova I L Shchaveleva T L Tsilevich B P Gottikh 《Bioorganicheskaia khimiia》1988,14(7):921-925
A convenient method has been proposed for the synthesis of 1,2-dihydroxy-4-oxahex-3-yl and 1-hydroxy-4-oxahex-3-yl derivatives of guanine, adenine, thymine and cytosine, acyclic nucleoside analogues lacking the 3'--4' bond. 相似文献
9.
S V Davenis A P Markov A V Golubev G B Smirnov 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1988,(9):14-17
The affect of mutations in chromosomal genes determining the realization of RecBC and RecF pathways of recombination in E. coli K12 on the frequency of transposon Tn5 precise excision from the genome of the conjugative plasmid pNM1 has been demonstrated. The pNM1 plasmid is a derivative of R100.1 and differs from the latter in the presence of Tn5 inactivating the tet gene of transposon Tn10. 相似文献
10.
I A Rudneva N N Finskaia Iu A Smirnov N V Kaverin 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1988,(9):32-36
Reassortment analysis of the pneumovirulence for mice marker of influenza virus has been performed. The original A/USSR/90/77 (H1H1) influenza virus strain or its mouse-adapted variant were crossed with a variant of A/Aichi/2/68 (H3N2) influenza virus highly virulent for mice. The reassortant having HA gene of the original A/USSR/90/77 virus and the other genes of the highly virulent A/Aichi/2/68 strain was avirulent for mice, whereas a similar reassortant possessing HA gene of the mouse-adapted A/USSR/90/77 strain was as virulent as A/Aichi/2/68 parent virus. The reasortant having HA and M genes of A/Aichi/2/68 and other genes of the mouse-adapted A/USSR/90/77 was moderately virulent, resembling in this respect the latter parent. The data indicates that changes in the different genes in course of viral adaptation to mice result in a differential acquisition of virulence for mice. 相似文献