全文获取类型
收费全文 | 243篇 |
免费 | 4篇 |
出版年
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 14篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 5篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有247条查询结果,搜索用时 31 毫秒
151.
Anna Y. Golovina Petr V. Sergiev Andrey V. Golovin Marina V. Serebryakova Irina Demina Vadim M. Govorun Olga A. Dontsova 《RNA (New York, N.Y.)》2009,15(6):1134-1141
Transfer RNA is highly modified. Nucleotide 37 of the anticodon loop is represented by various modified nucleotides. In Escherichia coli, the valine-specific tRNA (cmo5UAC) contains a unique modification, N6-methyladenosine, at position 37; however, the enzyme responsible for this modification is unknown. Here we demonstrate that the yfiC gene of E. coli encodes an enzyme responsible for the methylation of A37 in tRNA1Val. Inactivation of yfiC gene abolishes m6A formation in tRNA1Val, while expression of the yfiC gene from a plasmid restores the modification. Additionally, unmodified tRNA1Val can be methylated by recombinant YfiC protein in vitro. Although the methylation of m6A in tRNA1Val by YfiC has little influence on the cell growth under standard conditions, the yfiC gene confers a growth advantage under conditions of osmotic and oxidative stress. 相似文献
152.
Mironova EV Leont'eva SV Sheviakov SV Alekseeva SG Shvets VI Demina OV Krasnokutskaia IS Finkel'shteĭn EI Khodonov AA 《Bioorganicheskaia khimiia》2002,28(6):535-542
A method of simultaneous one-stage synthesis of three retinal derivatives (5,6-dioxo-5,6-seco-, 5,6-dihydro-5,6-epoxy-, and 4-oxoretinal) was proposed, with the yield of the first derivative being approximately 50%. These compounds are useful tools for studying the antitumor activity of retinoids, the reconstituted bacteriorhodopsin analogues with changed parameters of photocycle, and the reactivity of retinal derivatives in the processes of oxidation by molecular oxygen. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 6; see also http://www.maik.ru. 相似文献
153.
Bariliak IR Demina EA Kliushin DA Petunin IuI Savkina MIu 《T?Sitologii?a i genetika》2001,35(4):55-58
Insufficient fitness of experimental data with convenient linear and linear-quadratic models of "dose-effect" dependence for the number of chromosome aberrations of different types were revealed. Proposed method of approximation of the experimental "dose-effect" dependence with piece-linear splines allows to obtain more accurate results in the most cases and therefore is more preferable than the linear and linear-quadratic models. 相似文献
154.
Demina EA 《T?Sitologii?a i genetika》2002,36(5):11-15
A tendency of the increasing frequency of malignant neoplasms in liquidators at low radiation doses was found. The dose-effect dependence of the frequency of radiation markers (dicentric chromosomes) in lymphocytes of peripheral blood was revealed only in a group of liquidators of the ChNPP accident with malignant neoplasms in remote terms. 相似文献
155.
The development of mouth angle sacciform structure was studied in the ontogenesis of hamster Phodopus campbelli. It was found that the true sacciform structure with all components characteristic for adult animals was formed by the 20th day of postnatal development. Histological data have shown than the sacciform structure is formed in ontogenesis as a result of a complex epidermal transformation involving muscular and connective tissues which comprise the external coat. The structure studied is not formed on the basis of sebaceous glands and cannot be assigned to the class of gland as considered before. 相似文献
156.
Neomycin phosphate was obtained as a result of neomycin phosphorylation with aminoglycoside-phosphotransferase from Act. fradiae. It was isolated from the reaction mixture and purified. Successive ion exchange chromatography on columns with Amberlite IRC-50 (NH+4 form), Dowex 1 X 10 (OH- form) and Amberlite CG-50 (NH+4 form) was used for purification of the inactivation product. The findings of the elementary analysis of neomycin phosphate showed the presence of 1 mole of phosphorus per 1 mole of the antibiotic. From the results of the chemical analysis, IR- and NMR-spectrometry neomycin phosphate and neamine phosphate obtained from it by methanolysis were identified as neomycin-3'-phosphate and neamine-3'-phosphate, respectively. The data indicate that the enzyme isolated from Act. fradiae is aminoglycoside-3'-phosphotransferase. 相似文献
157.
KR N’Guessan BRD Aboua J Tison-Rosebery A Ouattara EP Kouamelan 《African Journal of Aquatic Science》2018,43(2):131-140
The ecology and taxonomy of the epilithic diatom flora of the Agnéby River, Ivory Coast were studied in 2012. Ten sites were investigated and diatoms were sampled on glass slides immersed for a period of 30 days during the wet and dry seasons. Physico-chemical parameters were measured at each site while sampling diatoms. Five taxa were largely dominant: Planothidium comperei CE Wetzel, N’Guessan and Tison-Rosebery, Eolimna minima (Grunow) Lange-Bertalot, Planothidium piaficum (JR Carter and Denny) CE Wetzel and Ector, Cocconeis schroederi Foged and Cocconeis scutellum var. parva (Grunow in Van Heurck) Cleve. Electrical conductivity, temperature, dissolved oxygen, nitrite and phosphorus were found to influence the distribution of taxa. 相似文献
158.
159.
160.
N. R. Kil’deeva M. A. Kasatkina M. G. Drozdova T. S. Demina S. A. Uspenskii S. N. Mikhailov E. A. Markvicheva 《Applied Biochemistry and Microbiology》2016,52(5):515-524
The influence of the conditions of the formation of chitosan hydrogels crosslinked with glutaraldehyde (GA) or genipin (the polysaccharide molecular weight, pH level, and concentration of the chitosan solution) on the gel time and the properties of biopolymer scaffolds for tissue engineering obtained by the freeze-drying of hydrogels was studied. The resulting scaffolds had different structures (morphology, degree of anisotropy, average pore size) and moisture-retaining capacities. The cytotoxicity of biodegradable scaffolds based on chitosan with a low content of genipin and GA was studied for the first time. Using the L929 mouse fibroblasts model line, we demonstrated that scaffolds based on chitosan with a molecular weight of 320 and 190 kDa crosslinked with genipin and GA (0.005 and 0.01 mol/mol of chitosan amino groups) are biocompatible. Using confocal laser microscopy, we demonstrated that the cells are uniformly distributed in all scaffold samples and they successfully grew and proliferated when cultured in vitro for 4 days. 相似文献