全文获取类型
收费全文 | 3256756篇 |
免费 | 240385篇 |
国内免费 | 5712篇 |
专业分类
耳鼻咽喉 | 44815篇 |
儿科学 | 106424篇 |
妇产科学 | 89790篇 |
基础医学 | 474279篇 |
口腔科学 | 89892篇 |
临床医学 | 296339篇 |
内科学 | 628352篇 |
皮肤病学 | 73172篇 |
神经病学 | 260389篇 |
特种医学 | 121786篇 |
外国民族医学 | 905篇 |
外科学 | 488365篇 |
综合类 | 72141篇 |
现状与发展 | 15篇 |
一般理论 | 1207篇 |
预防医学 | 257423篇 |
眼科学 | 75962篇 |
药学 | 239091篇 |
11篇 | |
中国医学 | 6877篇 |
肿瘤学 | 175618篇 |
出版年
2021年 | 25924篇 |
2019年 | 26685篇 |
2018年 | 37037篇 |
2017年 | 27892篇 |
2016年 | 31502篇 |
2015年 | 35377篇 |
2014年 | 50257篇 |
2013年 | 75310篇 |
2012年 | 103171篇 |
2011年 | 110173篇 |
2010年 | 65216篇 |
2009年 | 61724篇 |
2008年 | 102500篇 |
2007年 | 108976篇 |
2006年 | 110113篇 |
2005年 | 106901篇 |
2004年 | 102442篇 |
2003年 | 98235篇 |
2002年 | 94846篇 |
2001年 | 150366篇 |
2000年 | 154117篇 |
1999年 | 129242篇 |
1998年 | 37810篇 |
1997年 | 33468篇 |
1996年 | 33513篇 |
1995年 | 31653篇 |
1994年 | 29207篇 |
1993年 | 27427篇 |
1992年 | 99461篇 |
1991年 | 96573篇 |
1990年 | 93878篇 |
1989年 | 90442篇 |
1988年 | 83288篇 |
1987年 | 81306篇 |
1986年 | 76232篇 |
1985年 | 73173篇 |
1984年 | 54943篇 |
1983年 | 46678篇 |
1982年 | 28121篇 |
1979年 | 50110篇 |
1978年 | 35584篇 |
1977年 | 29641篇 |
1976年 | 28265篇 |
1975年 | 30012篇 |
1974年 | 36241篇 |
1973年 | 34535篇 |
1972年 | 32542篇 |
1971年 | 30477篇 |
1970年 | 28352篇 |
1969年 | 26811篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
921.
A E Valeev 《Neirofiziologiia》1986,18(2):273-282
The review describes properties of gamma-aminobutyric acid (GABA) receptors in the central nervous system of mammalians. Two pharmacologically different receptors--GABAA and GABAB--are involved into GABA-ergic inhibition. GABA receptors (bicuculline-sensitive) regulate chloride permeability of membranes and can be functionally enhanced by benzodiazepine and barbiturate. GABA receptors (bicuculline-insensitive) are suggested to regulate calcium permeability. 相似文献
922.
923.
Rifampin alone or with trimethoprim for contacts of children with Haemophilus influenzae type b infections. 总被引:1,自引:0,他引:1 下载免费PDF全文
T Jadavji R Cheung R M Bannatyne C G Prober 《Canadian Medical Association journal》1986,135(4):328-331
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days. 相似文献
924.
925.
926.
927.
928.
Theoretical calculation of relative binding affinity in host-guest systems. 总被引:5,自引:3,他引:2 下载免费PDF全文
T P Lybrand J A McCammon G Wipff 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(4):833-835
The relative free energy of binding the anions Cl- and Br- to the macrotricyclic receptor SC24 in water has been computed by a computer simulation technique. This result and an incidental result for the relative free energy of hydration of the anions are in excellent agreement with experimental data. The simulation approach to ligand-receptor interactions that is described here has significant potential as a predictive tool in chemistry, biochemistry, and pharmacology. 相似文献
929.
K Junge U Klinge B Klosterhalfen P R Mertens R Rosch A Schachtrupp F Ulmer V Schumpelick 《Journal of investigative surgery》2002,15(6):319-328
Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material. 相似文献
930.