全文获取类型
收费全文 | 1839篇 |
免费 | 134篇 |
出版年
2022年 | 24篇 |
2021年 | 43篇 |
2020年 | 17篇 |
2019年 | 31篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 55篇 |
2015年 | 58篇 |
2014年 | 68篇 |
2013年 | 95篇 |
2012年 | 161篇 |
2011年 | 134篇 |
2010年 | 94篇 |
2009年 | 91篇 |
2008年 | 113篇 |
2007年 | 127篇 |
2006年 | 94篇 |
2005年 | 110篇 |
2004年 | 103篇 |
2003年 | 78篇 |
2002年 | 83篇 |
2001年 | 22篇 |
2000年 | 19篇 |
1999年 | 11篇 |
1998年 | 18篇 |
1997年 | 18篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 6篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1976年 | 7篇 |
1974年 | 9篇 |
1973年 | 5篇 |
1972年 | 7篇 |
1971年 | 8篇 |
1969年 | 6篇 |
排序方式: 共有1973条查询结果,搜索用时 15 毫秒
1.
Experiments in mice have demonstrated that in the presence of influenza infection the suppressing effect of virulent shigellae on the secondary humoral and cell-mediated immune response is enhanced. Under such conditions avirulent shigellae can also show suppressing effect which is usually absent in these organisms. 相似文献
2.
Tsyganov V. E.; Pavlova Z. B.; Kravchenko L. V.; Rozov S. M.; Borisov A. Y.; Lutova L. A.; Tikhonovich I. A. 《Annals of botany》2000,86(5):975-981
Using ethyl methane sulfonate (EMS) treatment of the seeds ofline SGE, a new mutant of pea (Pisum sativum L.) with alterationsin root development was obtained. The mutant phenotype dependson the density of the growth substrate: on sand (a high densitysubstrate) the mutant forms a small compact curly root systemwhereas on vermiculite (a low density substrate) differencesbetween the root systems of the mutant and wild type plantsare less pronounced. Genetic analysis revealed that the mutantcarries a mutation in a new pea gene designedcrt (curly roots).Gene crt has been localized in pea linkage group V. The mutantline named SGEcrt showed increased sensitivity to exogenousauxin and an increased concentration of endogenous indole-3-aceticacid (IAA) in comparison with the wild type line SGE. Copyright2000 Annals of Botany Company Pisum sativum L., root development, garden pea mutant, curly roots, auxin, environmental stimulus response 相似文献
3.
Olga Maslova Oleg Fedevych Nadiia Shuvalova Olena Deryabina Volodymyr Zhovnir Miroslav Novak Peter Kruzliak 《Cell and tissue banking》2016,17(2):335-339
The need for selection of the optimal material for the manufacturing of cardio-patches can be resolved by the use of cryostored autologous pericardial tissue. This short communication is a concise fragment of a large-scale research and demonstrates only the efficiency of cell culturing before and after pericardial preservation in the low temperature conditions. 相似文献
4.
5.
6.
Ricardo Gonzalez-Mendez David Wemmer George Hahn Norma Wade-Jardetzky Oleg Jardetzky 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1982,720(3):274-280
A continuous-flow NMR culture system for mammalian cells has been developed on which 31P-NMR experiments under complete and strictly physiologic conditions have been performed. Observations on the response of the cellular metabolism to stresses such as starvation, low temperature and changes in environmental pH monitored by 31P-NMR are reported. The response of the intracellular pH relative to the external pH of the growth medium is studied. We find that under the experimental conditions used there exists a ΔpH varying between less than 0.2 and more than 0.6 pH units. These results are compatible with those obtained using other techniques. 相似文献
7.
8.
9.
V. N. Orlov V. B. Sycheva E. V. Cherepanova Yu. M. Borisov 《Russian Journal of Genetics》2013,49(4):417-427
The contact points of four karyotypic races (St. Petersburg, Moscow, Seliger and West Dvina) of the common shrew Sorex araneus L. were studied at the Valdai Hills (European Russia) in an area unimpeded by geographic barriers. The populations of the races are separated by narrow hybrid zones that represent the most complex heterozygous hybrid karyotypes. At these points of contact, the morphometric differentiation of karyotype races was examined in 12 cranial measurements in 190 shrews of a known karyotype. A comparison of the mean values in studied samples of immature shrews revealed statistically significant differences and the correlation of some measurements which describe the level of musculus temporalis. It has been proposed that morphometric differences in the karyotypic races were preserved and accumulated because of a 50% reduction of the frequencies of hybrids. The deviation from the Hardy-Weinberg ration in the frequencies of the genotype and haploid sets of chromosomes in the hybrid zones can be attributed to a number of fatalities of hybrid embryos or the nonrandom mating of karyotypic races. The ethological isolation might arise in the evolution of some karyotypic races from the reduced fitness of the hybrids. 相似文献
10.
Caixia Hou Abhisek Mandal Jürgen Rohr Oleg V. Tsodikov 《Structure (London, England : 1993)》2021,29(5):404-412.e4
- Download : Download high-res image (237KB)
- Download : Download full-size image