全文获取类型
收费全文 | 560篇 |
免费 | 10篇 |
专业分类
570篇 |
出版年
2021年 | 9篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 11篇 |
2016年 | 8篇 |
2015年 | 12篇 |
2014年 | 14篇 |
2013年 | 13篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 6篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 20篇 |
2002年 | 11篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 7篇 |
1995年 | 3篇 |
1992年 | 13篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 20篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 18篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1976年 | 3篇 |
1974年 | 5篇 |
1973年 | 9篇 |
1972年 | 11篇 |
1971年 | 9篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1968年 | 5篇 |
1967年 | 4篇 |
1966年 | 6篇 |
排序方式: 共有570条查询结果,搜索用时 15 毫秒
1.
2.
The authors discuss various aspects of a recently developed method permitting a detailed flow cytometric analysis of the individual cell karyotypes such as instrumentation, histochemistry, data proceeding algorithms. Possible drawbacks of the method and the ways of their overcoming are considered. Results of analysis of the Chinese hamster cells are presented that illustrate the possibilities of the method, including the metaphase chromosome distribution according to their fluorescence intensity, the analysed cell distribution according to their chromosomes number, the table in which the individual cell karyotypes are distributed according to their fluorescence. The results obtained show that the developed method may be successfully used for investigating chromosomal iNstability and heterogeneity of the mammalian cells. 相似文献
3.
The paramagnetic form of ribonucleotide reductase was detected by ESR method in human cervix tissues, especially in tumor ones. The magnetic relaxation rate was proved to be slower for this form than for that in normal animal tissues having a high level of proliferative activity or in Ehrlich tumor cells studied before. 相似文献
4.
5.
The radioprotective effect of cysteamine combined with the modification of the chromatin state by sodium butyrate has been studied using V-79 and CHEL lines of Chinese hamster cells and HeLa cells. Sodium butyrate enhances the chromatin sensitivity to nucleases and removes the radioprotective effect of cysteamine as measured by the yield of cells with chromosome aberrations. As is indicated by changes in the intensity of fluorescence of the DNA-ethidium bromide complex, measured by laser flow cytometry, the protective agent decreases the binding of the dye with both irradiated and nonirradiated DNA whereas ionizing radiation and sodium butyrate increase thereof. It is concluded that the radioprotective effect of cysteamine depends in its ability to reduce the susceptibility of DNA to nucleases. 相似文献
6.
One and 24 h following single X-irradiation (0.21 C/kg) of rabbit hind leg the content of free fatty acids and phospholipid lysoforms increased in the sarcoplasmic reticulum (SR) membrane of skeletal muscles. The results obtained are important in estimating the mechanisms of action of ionizing radiation on the structural and functional properties of SR. 相似文献
7.
Peter Ort Igor A. Zalunin Victor S. Gasparov Galina G. Chestukhina Valentin M. Stepanov 《Journal of Protein Chemistry》1995,14(4):241-249
Denaturation ofBacillus thuringiensis CryIIIA-endotoxin—an insecticidal protein, active againstColeoptera larvae—in concentrated guanidine hydrochloride solutions was pursued by fluorescence and circular dichroism spectroscopy and limited proteolysis. It was found that the protein consists of two fragments that differ by their stability to denaturation by guanidine hydrochloride atpH 3. The less stable fragment corresponds to the N-terminal-helical domain limited by Leu-279; the more stable one starts with Ile-280, contains about 330 amino acid residues, and corresponds to the molecule C-terminal moiety that consist of its two-structural domains forming a superdomain.Abbreviations BT
Bacillus thuringiensis
- Gdn-HCl
guanidine hydrochloride
- PAGE
electrophoresis in polyacrylamide gel
- SDS
sodium dodecylsulfate
- CD
circular dichroism 相似文献
8.
V M Stepanov A Y Strongin L S Isotova Z T Abramov 《Acta biologica et medica Germanica》1977,36(11-12):1509-1513
An intracellular serine proteinase was isolated from Bacillus subtilis, strain A-50. The molecular weight of the enzyme is 30000 +/- 1000, its amino acid composition is enriched in glutamic acid residues, the isoelectric point is 4.3, the N-terminal sequence Glu-Leu-Pro-Glu-Gly-Ile-Gln-Val-Ile-Lys-Ala-Pro-Glu-Leu-Xxx-Ala-Gln-Gly-Phe-Lys Gly-Ser-Asx-Ile-Lys-Ile-Ala-Val-Leu-Asx. The enzyme is structuraly homologous with secretory subtilisins. 相似文献
9.
N V Kha?darova G N Rudenskaia V M Stepanov N S Egorob 《Prikladnaia biokhimiia i mikrobiologiia》1991,27(3):375-380
The secretion of some proteolytic enzymes by Streptomyces thermovulgaris T 54 was studied using artificial chromogenic substrates of proteinases. Maximum accumulation of the enzymes hydrolysing Z-Glu-pNA and Z-Ala-Ala-Leu-pNA occurred during autolysis of the culture. Two peaks of activity were observed, when DNP-Gly-Gly-Ile-Arg was used as a substrate, one of them being correspondent to prevalence of dense colonies in the culture and the other to the prevalence of friable networks of hyphae. 相似文献
10.
Three genetic systems of blood groups of great gerbils were studied to reveal that different resistance patterns exist in rodents toward Yersinia pestis and Salmonella typhimurium. Extrapolation of the results obtained on relations of co-members of parasite systems contributes to understanding of some points of immunobiological mechanisms of dynamics of expizootic procedures. A hypothesis is proposed claiming that isoantigenic blood structure of the host is responsible for formation of population resistance to infection. 相似文献