全文获取类型
收费全文 | 3233198篇 |
免费 | 266491篇 |
国内免费 | 13533篇 |
专业分类
耳鼻咽喉 | 44464篇 |
儿科学 | 96753篇 |
妇产科学 | 81011篇 |
基础医学 | 518765篇 |
口腔科学 | 88795篇 |
临床医学 | 287757篇 |
内科学 | 566021篇 |
皮肤病学 | 87031篇 |
神经病学 | 276423篇 |
特种医学 | 127076篇 |
外国民族医学 | 105篇 |
外科学 | 512028篇 |
综合类 | 96156篇 |
现状与发展 | 23篇 |
一般理论 | 2156篇 |
预防医学 | 264281篇 |
眼科学 | 73818篇 |
药学 | 224181篇 |
24篇 | |
中国医学 | 9558篇 |
肿瘤学 | 156796篇 |
出版年
2021年 | 54713篇 |
2020年 | 34891篇 |
2019年 | 57862篇 |
2018年 | 70361篇 |
2017年 | 53593篇 |
2016年 | 59071篇 |
2015年 | 73556篇 |
2014年 | 107679篇 |
2013年 | 172735篇 |
2012年 | 83461篇 |
2011年 | 81665篇 |
2010年 | 114027篇 |
2009年 | 119342篇 |
2008年 | 69972篇 |
2007年 | 71496篇 |
2006年 | 83166篇 |
2005年 | 78496篇 |
2004年 | 80625篇 |
2003年 | 71821篇 |
2002年 | 61967篇 |
2001年 | 102691篇 |
2000年 | 95606篇 |
1999年 | 95661篇 |
1998年 | 64479篇 |
1997年 | 62468篇 |
1996年 | 60216篇 |
1995年 | 55682篇 |
1994年 | 49667篇 |
1993年 | 46439篇 |
1992年 | 66430篇 |
1991年 | 62739篇 |
1990年 | 59258篇 |
1989年 | 58844篇 |
1988年 | 54244篇 |
1987年 | 52984篇 |
1986年 | 49892篇 |
1985年 | 50365篇 |
1984年 | 45975篇 |
1983年 | 42366篇 |
1982年 | 40558篇 |
1981年 | 38241篇 |
1980年 | 35958篇 |
1979年 | 36949篇 |
1978年 | 33081篇 |
1977年 | 30854篇 |
1976年 | 27644篇 |
1975年 | 26211篇 |
1974年 | 26589篇 |
1973年 | 25256篇 |
1972年 | 23754篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems 总被引:1,自引:0,他引:1
Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 +/- 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10(-6)-10(-4) M) of kainic acid (10(-8)-10(-6) M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10(-4) M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not by electrical stimulation. The addition of GABA (10(-5)-10(-3) M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10(-6)-10(-4) M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation. 相似文献
992.
C.T. PEASE M. FENNELL R.C.D. STAUGHTON D.A. BREWERTON 《The British journal of dermatology》1987,117(2):161-167
Polymorphonuclear leukocyte (PMN) migration was assessed in vitro using the agarose plate method in patients with psoriasis vulgaris, and compared with an age- and sex-matched control group. No significant difference was found between the two groups in the PMN response to the chemotactic substances F-Met-Leu-Phe (FMLP) or zymosan activated serum (ZAS). Equally, the chemokinetic or chemotactic potential of psoriatic serum did not differ from control serum. Our results do not support a primary abnormality of PMN function in psoriasis. 相似文献
993.
994.
995.
S B Wieslander B T Mortensen L Binderup N I Nissen 《European journal of haematology》1987,39(1):35-38
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily. 相似文献
996.
997.
IgG-maleimide peroxidase, Fab'-maleimide peroxidase, polymer and monomer types of Fab'-periodate peroxidase were prepared from an antibody against rat lipoamide dehydrogenase, a component of the pyruvate dehydrogenase complex which is located in mitochondria. They were examined for immunohistochemical staining of the rat kidney. Fab'-maleimide peroxidase was the best for staining mitochondrial protein. IgG-maleimide peroxidase and the monomer type of Fab'-periodate peroxidase had the same intensity of staining. The polymer type of Fab'-periodate peroxidase could not stain the lipoamide dehydrogenase. 相似文献
998.
999.
1000.