全文获取类型
收费全文 | 490315篇 |
免费 | 45256篇 |
国内免费 | 252篇 |
出版年
2016年 | 7077篇 |
2015年 | 11436篇 |
2014年 | 12143篇 |
2013年 | 15514篇 |
2012年 | 15662篇 |
2011年 | 13664篇 |
2010年 | 9946篇 |
2009年 | 9265篇 |
2008年 | 11139篇 |
2007年 | 11722篇 |
2006年 | 11114篇 |
2005年 | 16343篇 |
2004年 | 15225篇 |
2003年 | 13282篇 |
2002年 | 10776篇 |
2001年 | 18145篇 |
2000年 | 17661篇 |
1999年 | 15144篇 |
1998年 | 5225篇 |
1997年 | 5400篇 |
1996年 | 5090篇 |
1995年 | 4844篇 |
1994年 | 4752篇 |
1993年 | 4717篇 |
1992年 | 13714篇 |
1991年 | 13594篇 |
1990年 | 13636篇 |
1989年 | 13310篇 |
1988年 | 12623篇 |
1987年 | 11840篇 |
1986年 | 11043篇 |
1985年 | 11481篇 |
1984年 | 9240篇 |
1983年 | 7892篇 |
1982年 | 5962篇 |
1981年 | 5330篇 |
1980年 | 4980篇 |
1979年 | 8930篇 |
1978年 | 6899篇 |
1977年 | 6398篇 |
1976年 | 6142篇 |
1975年 | 6797篇 |
1974年 | 7472篇 |
1973年 | 7312篇 |
1972年 | 6820篇 |
1971年 | 6260篇 |
1970年 | 5412篇 |
1969年 | 5422篇 |
1968年 | 5012篇 |
1967年 | 4402篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
221.
222.
223.
224.
A Rauch R A Pfeiffer G Leipold H Singer M Tigges M Hofbeck 《American journal of human genetics》1999,64(2):659-666
225.
L. G. Goodwin 《BMJ (Clinical research ed.)》1953,1(4805):311-313
226.
Microsatellite DNA in peach (Prunus persica L. Batsch) and its use in fingerprinting and testing the genetic origin of cultivars. 总被引:11,自引:0,他引:11
R Testolin T Marrazzo G Cipriani R Quarta I Verde M T Dettori M Pancaldi S Sansavini 《Génome》2000,43(3):512-520
We isolated and sequenced 26 microsatellites from two genomic libraries of peach cultivar 'Redhaven', enriched for AC/GT and AG/CT repeats, respectively. For 17 of these microsatellites, it was possible to demonstrate Mendelian inheritance. Microsatellite polymorphism was assayed in 50 peach and nectarine cultivars. Of the 1300 PCRs carried out, all but two produced amplified products of the expected size. All microsatellites were polymorphic, showing 2-8 alleles per locus. Heterozygosity ranged from 0.04-0.74 (mean 0.47); the discrimination power (PD) ranged from 0.04-0.84 (mean 0.60). Cultivar heterozygosity varied greatly, with one cultivar ('Independence') being homozygous at all loci. The set of microsatellites discriminated all cultivars investigated, except several sport mutations, i.e., 'Dixitime' vs. 'Springcrest', 'Compact Redhaven' vs. 'Redhaven', and two pairs of cultivars, 'Venus' vs. 'Orion' and 'Elegant Lady' vs. 'Rome Star', whose pedigrees are controversial. We were able to analyze the paternity of several cultivars. In most cases, the parenthood was confirmed. The comparison of three long-living 'Redhaven' accessions supplied by different repositories did not provide any evidence of somatic instability of microsatellites. Hence, microsatellites, ranked according to their information content, are recommended as markers of choice for peach fingerprinting and suggestions are provided for interpreting band profiles and the correct sizing of alleles. 相似文献
227.
Ia I Serkiz A I Lipskaia L B Pinchuk V V Trishin Iu F Kataevski? G N Koval' 《Radiobiologiia》1991,31(5):629-634
Irradiation conditions in which laboratory animals were kept in experimental laboratories of Chernobyl and Kiev after the accident at the Chernobyl A.P.S. are described. The data are presented on the spectral structural and activity of radionuclides in the diet as well as in the organs and tissues of the animals. The radiation loads have been estimated with regard to an external gamma component and the internal one contributed by the incorporated radionuclides. It has been shown that radiation doses received by the animals during their lifetime due to these contributions do not exceed units of cGy. 相似文献
228.
Steven J. Tucker David McClelland Kristina Sep?i? Roderick H. Scott 《生物化学与生物物理学报:生物膜》2003,1614(2):171-181
The ability of two alkyl pyridinium sponge toxin preparations (poly-APS and halitoxin) to form transient pores/lesions in cell membranes and allow transfection of plasmid cDNA have been investigated using HEK 293 cells. Poly-APS and halitoxin preparations caused a collapse in membrane potential, reductions in input resistance and increased Ca2+ permeability. At least partial recovery was observed after poly-APS application but recovery was more rarely seen with halitoxin. The transfection with plasmid cDNAs for an enhanced green fluorescent protein (EGFP) and human tumour necrosis factor receptor 2 (TNFR2) was assessed for both toxin preparations and compared with lipofectamine. Stable transfection was achieved with poly-APS although it was less efficient than lipofectamine. These results show that viable cells transfected with alien cDNA can be obtained using novel transient pore-forming alkyl pyridinium sponge toxins and a simple pre-incubation protocol. This provides the first proof of principle that pore-forming alkyl pyridinium compounds can be used to deliver cDNA to the intracellular environment without permanently compromising the plasma membrane. 相似文献
229.
V V Snitinski? 《Zhurnal evoliutsionno? biokhimii i fiziologii》1989,25(5):583-588
[2-14C] leucine, [1-14C] alanine, [1-14C] glucose, [1-14C] lactate and [1-14C] pyruvate utilization in the protein synthesis has been studied in vivo at early stages of postnatal development of piglets. It has been established, that during the first 24 hours after birth the protein synthesis intensity, judging by [2-14C] leucine incorporation, in liver, skeletal muscle, duodenal wall and subcutaneous tissue of piglets increases 5, 7, 6.5 and 2.1 times respectively. At the age of 1-2 h the radioactive carbon incorporation from [1-14C] glucose into the brain proteins is more pronounced than into the proteins of liver and skeletal muscle. During the first days of life the intensity of the label incorporation from [1-14C] glucose into liver and skeletal muscle proteins of piglets is enhanced, whereas in brain it remains at the same level. The degree of 14C carbon incorporation from [1-14C]-alanine, [1-14C] pyruvate and [1-14C] lactate into the liver and skeletal muscle proteins of 5-days-old piglets is approximately the same, 14C substrates of protein synthesis in brain and subcutaneous adipose tissue having some peculiarities. 相似文献
230.