全文获取类型
收费全文 | 70028篇 |
免费 | 6303篇 |
国内免费 | 53篇 |
出版年
2021年 | 1190篇 |
2020年 | 687篇 |
2019年 | 909篇 |
2018年 | 1350篇 |
2017年 | 1095篇 |
2016年 | 1914篇 |
2015年 | 3106篇 |
2014年 | 3451篇 |
2013年 | 4090篇 |
2012年 | 5300篇 |
2011年 | 4976篇 |
2010年 | 3217篇 |
2009年 | 2808篇 |
2008年 | 4049篇 |
2007年 | 3747篇 |
2006年 | 3481篇 |
2005年 | 3137篇 |
2004年 | 3098篇 |
2003年 | 2741篇 |
2002年 | 2395篇 |
2001年 | 2010篇 |
2000年 | 1870篇 |
1999年 | 1509篇 |
1998年 | 700篇 |
1997年 | 634篇 |
1996年 | 542篇 |
1995年 | 527篇 |
1994年 | 459篇 |
1993年 | 434篇 |
1992年 | 890篇 |
1991年 | 751篇 |
1990年 | 695篇 |
1989年 | 697篇 |
1988年 | 595篇 |
1987年 | 571篇 |
1986年 | 494篇 |
1985年 | 504篇 |
1984年 | 407篇 |
1983年 | 336篇 |
1982年 | 302篇 |
1981年 | 278篇 |
1980年 | 264篇 |
1979年 | 343篇 |
1978年 | 323篇 |
1977年 | 255篇 |
1976年 | 271篇 |
1975年 | 256篇 |
1974年 | 304篇 |
1973年 | 255篇 |
1972年 | 237篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Although acupuncture therapy is widely used in traditional Asian medicine for the treatment of diverse internal organ disorders, its underlying biological mechanisms are largely unknown. Here, we investigated the functional involvement of acupuncture stimulation (AS) in the regulation of inflammatory responses. TNF-α production in mouse serum, which was induced by lipopolysaccharide (LPS) administration, was decreased by manual acupuncture (MAC) at the zusanli acupoint (stomach36, ST36). In the spleen, TNF-α mRNA and protein levels were also downregulated by MAC and were recovered by using a splenic neurectomy and a vagotomy. c-Fos, which was induced in the nucleus tractus solitarius (NTS) and dorsal motor nucleus of the vagus nerve (DMV) by LPS and electroacupuncture (EAC), was further increased by focal administration of the AMPA receptor blocker CNQX and the purinergic receptor antagonist PPADS. TNF-α levels in the spleen were decreased by CNQX and PPADS treatments, implying the involvement of inhibitory neuronal activity in the DVC. In unanesthetized animals, both MAC and EAC generated c-Fos induction in the DVC neurons. However, MAC, but not EAC, was effective in decreasing splenic TNF-α production. These results suggest that the therapeutic effects of acupuncture may be mediated through vagal modulation of inflammatory responses in internal organs. 相似文献
102.
103.
104.
Purification, characterization and immunolocalization of fimbrial protein from Porphyromonas (bacteroides) gingivalis. 总被引:3,自引:0,他引:3
H T Sojar J Y Lee G S Bedi M I Cho R J Genco 《Biochemical and biophysical research communications》1991,175(2):713-719
Rapid and reproducible method is described here for the purification of the 43 kDa fimbrial protein from P. gingivalis by preferential fractionation in the presence of 1% SDS and 0.2M of a bivalent cation at pH 6.5. Homogeneity of the purified 43 kDa was confirmed by SDS-PAGE and Western blot analysis using monoclonal and polyclonal antibodies raised against this protein. Amino acid composition and the amino acid sequence of the first 30 amino acid residues of the purified fimbriae are consistent with the composition and sequence predicted from the cloned gene of the fimbrial subunit. Circular dichroism spectra shows high levels of beta-sheet structure. The purified 43 kDa polymer shows fimbriae-like morphology under the electron microscope. Ultrastructural localization of the 43 kDa protein by the immunogold technique revealed specific labeling of the fimbriae with a diameter of approximately 3.5 to 5.0 nm. Localization of this protein suggest that the 43 kDa component is a fimbrial subunit. 相似文献
105.
Avian oviductal fluids contain phosphorylating-dephosphorylating enzymes that might function in sperm-oocyte interactions. Phosphorprotein phosphatase and protein kinase have been purified 20-fold and 40-fold, respectively. The latter easily aggregates and is highly labile. Other properties are comparable to those of holoenzymes. 相似文献
106.
F. H. Young 《BMJ (Clinical research ed.)》1950,2(4670):97-99
107.
108.
109.
110.