全文获取类型
收费全文 | 56818篇 |
免费 | 5704篇 |
国内免费 | 3061篇 |
出版年
2024年 | 68篇 |
2023年 | 480篇 |
2022年 | 1249篇 |
2021年 | 2337篇 |
2020年 | 1511篇 |
2019年 | 1897篇 |
2018年 | 2001篇 |
2017年 | 1436篇 |
2016年 | 2032篇 |
2015年 | 2855篇 |
2014年 | 3391篇 |
2013年 | 3715篇 |
2012年 | 4291篇 |
2011年 | 3999篇 |
2010年 | 2487篇 |
2009年 | 2106篇 |
2008年 | 2569篇 |
2007年 | 2315篇 |
2006年 | 2164篇 |
2005年 | 1794篇 |
2004年 | 1525篇 |
2003年 | 1384篇 |
2002年 | 1211篇 |
2001年 | 2832篇 |
2000年 | 2617篇 |
1999年 | 2033篇 |
1998年 | 757篇 |
1997年 | 800篇 |
1996年 | 716篇 |
1995年 | 654篇 |
1994年 | 583篇 |
1993年 | 478篇 |
1992年 | 1003篇 |
1991年 | 810篇 |
1990年 | 698篇 |
1989年 | 563篇 |
1988年 | 427篇 |
1987年 | 329篇 |
1986年 | 265篇 |
1985年 | 216篇 |
1984年 | 142篇 |
1983年 | 116篇 |
1982年 | 77篇 |
1981年 | 50篇 |
1980年 | 35篇 |
1979年 | 41篇 |
1978年 | 27篇 |
1976年 | 31篇 |
1973年 | 30篇 |
1970年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A method based on the infection of CaCo-2 cells and molecular hybridization with a specific cDNA probe has been developed for the detection of infectious astroviruses in environmental samples. By this procedure wild-type astroviruses have been detected in water from an area where a concurrent gastroenteritis outbreak was reported. 相似文献
82.
83.
84.
85.
86.
Xu Zhang Wei Zhang Santosh L. Saraf Mehdi Nouraie Jin Han Michel Gowhari Johara Hassan Galina Miasnikova Adelina Sergueeva Sergei Nekhai Rick Kittles Roberto F. Machado Joe G. N. Garcia Mark T. Gladwin Martin H. Steinberg Paola Sebastiani Donald A. McClain Victor R. Gordeuk 《Human genetics》2015,134(8):895-904
87.
Ke Wang Feiyun Xu Wei Yuan Dongping Zhang Jianping Liu Leyun Sun Liyou Cui Jianhua Zhang Weifeng Xu 《The Plant journal : for cell and molecular biology》2021,107(6):1603-1615
Heterotrimeric G protein is involved in plant growth and development, while the role of rice (Oryza sativa) G protein γ subunit qPE9-1 in response to low-phosphorus (LP) conditions remains unclear. The gene expression of qPE9-1 was significantly induced in rice roots under LP conditions. Rice varieties carrying the qPE9-1 allele showed a stronger primary root response to LP than the varieties carrying the qpe9-1 allele (mutant of the qPE9-1 allele). Transgenic rice plants with the qPE9-1 allele had longer primary roots and higher P concentrations than those with the qpe9-1 allele under LP conditions. The plasma membrane (PM) H+-ATPase was important for the qPE9-1-mediated response to LP. Furthermore, OsGF14b, a 14-3-3 protein that acts as a key component in activating PM H+-ATPase for root elongation, is also involved in the qPE9-1 mediation. Moreover, the overexpression of OsGF14b in WYJ8 (carrying the qpe9-1 allele) partially increased primary root length under LP conditions. Experiments using R18 peptide (a 14-3-3 protein inhibitor) showed that qPE9-1 is important for primary root elongation and H+ efflux under LP conditions by involving the 14-3-3 protein. In addition, rhizosheath weight, total P content, and the rhizosheath soil Olsen-P concentration of qPE9-1 lines were higher than those of qpe9-1 lines under soil drying and LP conditions. These results suggest that the G protein γ subunit qPE9-1 in rice plants modulates root elongation for phosphorus uptake by involving the 14-3-3 protein OsGF14b and PM H+-ATPase, which is required for rice P use. 相似文献
88.
X. M. Zhou P. H.-S. Jen 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2000,186(4):389-398
This study examines the role of neural inhibition in auditory spatial selectivity of inferior collicular neurons of the big
brown bat, Eptesicus fuscus, using a two-tone inhibition paradigm. Two-tone inhibition decreases auditory spatial response areas but increases the slopes
of directional sensitivity curves of inferior collicular neurons. Inferior collicular neurons have either directionally-selective
or hemifield directional sensitivity curves. A directionally-selective curve always has a peak which is at least 50% larger
than the minimum. A hemifield directional sensitivity curve rises from an ipsilateral angle by more than 50% and either reaches
a plateau or declines by less than 50% over a range of contralateral angles. Two-tone inhibition does not change directionally-selective
curves but changes most hemifield directional sensitivity curves into directionally-selective curves. Auditory spatial selectivity
determined both with and without two-tone inhibition increases with increasing best-excitatory frequency. Sharpening of auditory
spatial selectivity by two-tone inhibition is larger for neurons with smaller differences between excitatory and inhibitory
best frequencies. The effect of two-tone inhibition on auditory spatial selectivity increases with increasing inhibitory tone
intensity but decreases with increasing intertone interval. The implications of these findings in bat echolocation are discussed.
Accepted: 18 January 2000 相似文献
89.
X. Y. Li C. M. Han Y. Wang H. Z. Liu Z. F. Wu Q. H. Gao S. H. Zhao 《Animal genetics》2010,41(5):537-540
RIG-1 signalling is responsible for the detection of cytoplasmic viral RNA molecules. DEXH (Asp-Glu-X-His) box polypeptide 58 (encoded by DHX58) is a negative regulator of the RIG-1 signalling pathway. In human, the DHX58 gene can be upregulated and can inhibit the RIG-1 signalling pathway during viral infection. In this study, porcine DHX58 gene expression patterns were studied. According to our results, the porcine DHX58 gene was upregulated not only by the stimulation of Poly I:C but also by the stimulation of 1ipopolysaccharides (LPS). One polymorphism (g.4919G>C), detected in the ninth intron, was significantly associated with some blood parameters including the red cell distribution width of 1-day-old pigs and white blood cell counts, lymphocyte absolute counts, and platelet distribution width of 17-day-old pigs (P < 0.05). Moreover, the individuals with the genotype GG have a significantly higher mean white blood cell count than individuals with genotype CC or GC (P < 0.05). Our study indicates that DHX58 is an important gene that is associated with the immune response in swine. 相似文献
90.