全文获取类型
收费全文 | 548篇 |
免费 | 8篇 |
专业分类
556篇 |
出版年
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 16篇 |
2016年 | 15篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 22篇 |
2012年 | 23篇 |
2011年 | 17篇 |
2010年 | 18篇 |
2009年 | 7篇 |
2008年 | 24篇 |
2007年 | 23篇 |
2006年 | 19篇 |
2005年 | 24篇 |
2004年 | 14篇 |
2003年 | 10篇 |
2002年 | 19篇 |
2001年 | 14篇 |
2000年 | 19篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1992年 | 5篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 15篇 |
1978年 | 4篇 |
1976年 | 6篇 |
1975年 | 11篇 |
1974年 | 18篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1971年 | 13篇 |
1970年 | 7篇 |
1969年 | 6篇 |
1968年 | 8篇 |
1967年 | 9篇 |
1966年 | 9篇 |
1965年 | 3篇 |
排序方式: 共有556条查询结果,搜索用时 15 毫秒
521.
M D Kirnos S A Volkova N I Ganicheva I B Kudriashova B F Vaniushin 《Biokhimii?a (Moscow, Russia)》1983,48(10):1587-1595
In etiolated coleoptiles and initial leaf of developing wheat shoots the DNA synthesis is periodical and synchronous. In the initial leaf each step of DNA synthesis results in a stepwise increase of DNA content and is doubled at the first three steps. During the leaf plane formation the synthesis of nuclear DNA (nDNA) is decreased, while that of mitochondrial DNA (mitDNA) continues in synchronous cycles. This is the cause of relative stabilization of DNA content per unit of leaf plane length. The DNA increase in this organ occurs due to synchronous synthesis of nDNA and mitDNA in intercalary meristem cells. In coleoptiles a marked replication of nDNA is observed at the first three steps of the synthesis; in each cycle nDNA synthesis precedes that of mitDNA. With completion of coleoptile formation the nDNA synthesis in it practically ceases, whereas that of mitDNA continues in synchronous cycles. MitDNA is non-methylated and its composition (56 mol.% GC) differs significantly from that of the newly synthesized nDNA (44 mol.% GC; 100 X m5C/(C + m5C) = 16-17%). It may be concluded that in various organs of wheat shoots the composition and methylation of newly synthesized DNA depend on the age of the shoot and on the ratio of nDNA/mitDNA syntheses. 相似文献
522.
Iu M Seleznev S M Danilov N G Volkova L A Medvedeva 《Biokhimii?a (Moscow, Russia)》1979,44(2):245-251
Accumulation of 3H-dexamethasone by the nuclei in a cell-free system was studied. The increase in temperature from 0 degrees to 20 degrees C and treatment of cytosol by KCl (0.4 M) or theophylline (10mM) significantly increased the absorption the bound hormone by the nuclear fraction. Activation of the steroid-protein complex induced by temperature and addition of theophylline did not change its size. The increase in the ionic strength decreased the Stokes radius from 53 A down to 39.5 A and the sedimentation coefficient value from 7S down to 4S. It is concluded that the heart tissue cytoplasm contains a glucocorticoid receptor. 相似文献
523.
L F Morozova N I Belianchikova R M Radzikhovskaia A Iu Baryshnikov M A Volkova 《Biulleten' eksperimental'no? biologii i meditsiny》1979,87(6):574-576
The presence of the common antigen on B lymphocytes of healthy donors and myeloblasts of patients with chronic myeloid leukemia in blastic crisis was observed with antimyeloblastic serum in the indirect surface immunofluorescence test. The cytotoxic test showed this antigen in the blastic cells in 27 out of 57 patients with CML BC, in 3 of 11 patients with acute lymphoid leukemia, in 1 of 8 patients with chronic lymphoid leukemia and in 2 of 2 patients with undifferentiated leukemia. The antigen was not found in the peripheral blood cells of healthy donors. 相似文献
524.
525.
N N Kostiukova N A Korzhueva S A Derkach L Sh Bagirova Z A Merzeniuk L A Gul'man V N Niiakaia M O Volkova 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1992,(7-8):14-17
In 1985-1989 the etiological structure of acute bacterial meningitides (ABM) in children was studied in 4 largest industrial cities in different regions of the European part of the former USSR, as well as in 2 industrial cities of western Siberia. Due to the common methodological approach used in all investigations, comparable data were obtained in all cities. These investigations revealed that meningococci caused 53.0-86.7% of all cases of ABM in children, which corresponded to moderately increased morbidity rate in meningococcal infection (3.9-11.0 cases per 100,000 of the population, mostly 5.0-7.0 cases) in these cities with its progressive decrease during 3-4 years of observation. The gradual change of meningococci from group A, prevailing in the '70s and early '80s, to group B and in some cases the appearance of group C meningococci, accompanied by a decrease in morbidity rate, were noted. In St. Petersburg the indices of ABM morbidity in children aged up to 5 years for 1987 and 1988, caused by Haemophilus influenzae (0.74 and 4.13) and pneumococci (3.23 and 4.86), could be calculated. A great number of ABM cases of unclear etiology (15.9-33.3%) suggests that the number of ABM cases caused by these two infective agents was underestimated. 相似文献
526.
N A Spiridonov M A Kostenko S P Volkova A G Pogorelov M N Kondrashova 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1984,78(1):207-210
A procedure for isolating biologically active substances from Galleria mellonella using a culture of isolated giant neurons of mollusc Lymnaea stagnalis as a test-system is described. Fractions capable of activating neurites and inhibiting aggregation of neuronal cells within a range of concentrations from 1 to 30 micrograms/ml were isolated. The fractions obtained have in their chemical composition about 10.5% N, also contain P and S. They have a carbohydrate component. 相似文献
527.
528.
529.
530.