全文获取类型
收费全文 | 318257篇 |
免费 | 29330篇 |
国内免费 | 22592篇 |
专业分类
耳鼻咽喉 | 2972篇 |
儿科学 | 3398篇 |
妇产科学 | 4922篇 |
基础医学 | 39694篇 |
口腔科学 | 5484篇 |
临床医学 | 44459篇 |
内科学 | 47675篇 |
皮肤病学 | 3078篇 |
神经病学 | 18137篇 |
特种医学 | 11904篇 |
外国民族医学 | 213篇 |
外科学 | 32677篇 |
综合类 | 49582篇 |
现状与发展 | 76篇 |
一般理论 | 20篇 |
预防医学 | 18935篇 |
眼科学 | 9498篇 |
药学 | 32455篇 |
328篇 | |
中国医学 | 17381篇 |
肿瘤学 | 27291篇 |
出版年
2024年 | 660篇 |
2023年 | 4419篇 |
2022年 | 8806篇 |
2021年 | 16171篇 |
2020年 | 11915篇 |
2019年 | 10812篇 |
2018年 | 11398篇 |
2017年 | 9900篇 |
2016年 | 9344篇 |
2015年 | 14330篇 |
2014年 | 17776篇 |
2013年 | 15327篇 |
2012年 | 22800篇 |
2011年 | 25798篇 |
2010年 | 15881篇 |
2009年 | 12240篇 |
2008年 | 17010篇 |
2007年 | 17003篇 |
2006年 | 17040篇 |
2005年 | 16763篇 |
2004年 | 10657篇 |
2003年 | 9753篇 |
2002年 | 8427篇 |
2001年 | 7459篇 |
2000年 | 8265篇 |
1999年 | 8994篇 |
1998年 | 5438篇 |
1997年 | 5463篇 |
1996年 | 4332篇 |
1995年 | 3922篇 |
1994年 | 3213篇 |
1993年 | 2099篇 |
1992年 | 2826篇 |
1991年 | 2416篇 |
1990年 | 2117篇 |
1989年 | 1859篇 |
1988年 | 1564篇 |
1987年 | 1305篇 |
1986年 | 1089篇 |
1985年 | 912篇 |
1984年 | 526篇 |
1983年 | 373篇 |
1982年 | 242篇 |
1981年 | 238篇 |
1980年 | 188篇 |
1979年 | 221篇 |
1978年 | 82篇 |
1977年 | 89篇 |
1974年 | 102篇 |
1973年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
991.
Bloodflowvariationandenergymetabolisminthegastricmucosafollowing7.5%hypertonicsalineresuscitationWangJunyi(王俊义);WuGuosheng;(吴... 相似文献
992.
993.
The edema-producing activity of NNAVPLA2, an acidic phospholipase A2 (PLA2) enzyme from Naja naja atra venom (NNAV), was less potent than that of TMVPLA2 II, a basic PLA; from Trimeresurus mucrosquamatus venom (TMV). These edema-forming effects were greatly suppressed by pretreatment of rats with diphenhydramine/ methysergide or compound 48/80, which reduced the tissue content of histamine and serotonin. Heparin abolished and suppressed the paw edema caused by protamine and TMVPLA2 II, respectively, but had no effect on the NNAVPLA2-induced response. In isolated rat peritoneal mast cells, both PLA2 concentration dependently induced the release of histamine and β-glueuronidase. Again, TMVPLA2 II was more potent than NNAVPLA2. This degranulation effect of mast cells caused by TMVPLA2 II and protamine was inhibited by heparin, while that caused by NNAVPLA2 was unaffected. The edema-forming and mast cell degranulation effects were greatly decreased in both PBPB-modified NNAVPLA2 and PBPB-modified TMVPLA2 II, in which the catalytic activity of the enzymes was completely lost. PBPB-modified TMVPLA2 II-induced paw edema was also suppressed by heparin. Furthermore, this edematous response was totally reversed in rat pretreated with aspirin in combination with diphenhydramine and methysergide. These results suggest that the edema-forming effect of PLA2 is probably dependent on the presence of catalytic, positive charge and pharmacological sites on its molecule. 相似文献
994.
995.
996.
997.
998.
You M. Lu Bu F. Lu Yu L. Yan Tin H. Yan Xiaon P. Ho Wen J. Wang 《The European journal of neuroscience》1993,5(10):1334-1338
The activation of membrane-associated phospholipase C is rapidly and transiently induced in the central nervous system by a variety of stimuli. Ischaemic brain injury is one of the situations that leads to a dramatic increase in polyphosphoinositide (PPI) turnover. In this study, stimulation of PPI hydrolysis by glutamate (500 μM) was measured in hippocampal slices from rats up to 21 days after an ischaemic insult of 30 min. Ischaemia was induced using the four-vessel occlusion method. PPI hydrolysis elicited by glutamate was significantly increased in the slices prepared from ischaemic rats 24 h after reperfusion, the accumulation of inositol phosphates (InsPs ) and inositol 1,4,5-trisphosphate (InsP3 ) was 614±74% ( n = 8) and 182±11% ( n = 9) of the basal level respectively. This potentiation was also observed 21 days after ischaemia. Hyper-responsiveness to glutamate was also accompanied by an increase in AIF− 4 -stimulated formation of [3 H]inositol phosphates. In addition, global ischaemia did not change either high-affinity [3 H]glutamate binding in hippocampal membranes or the stimulation of PPI hydrolysis by carbachol or noradrenaline in hippocampal slices. The present results suggest that the increased responsiveness to glutamate is the result, at least in part, of functional changes at the G-protein level, and may contribute to the pathophysiology of ischaemic brain injury or to the regenerative phenomena that accompany ischaemic damage. 相似文献
999.
1000.