全文获取类型
收费全文 | 4284篇 |
免费 | 407篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 122篇 |
妇产科学 | 108篇 |
基础医学 | 519篇 |
口腔科学 | 88篇 |
临床医学 | 497篇 |
内科学 | 1007篇 |
皮肤病学 | 35篇 |
神经病学 | 326篇 |
特种医学 | 181篇 |
外科学 | 363篇 |
综合类 | 174篇 |
一般理论 | 8篇 |
预防医学 | 499篇 |
眼科学 | 40篇 |
药学 | 381篇 |
中国医学 | 8篇 |
肿瘤学 | 314篇 |
出版年
2021年 | 70篇 |
2020年 | 49篇 |
2019年 | 66篇 |
2018年 | 77篇 |
2017年 | 43篇 |
2016年 | 50篇 |
2015年 | 68篇 |
2014年 | 95篇 |
2013年 | 146篇 |
2012年 | 178篇 |
2011年 | 227篇 |
2010年 | 94篇 |
2009年 | 105篇 |
2008年 | 176篇 |
2007年 | 225篇 |
2006年 | 202篇 |
2005年 | 212篇 |
2004年 | 198篇 |
2003年 | 173篇 |
2002年 | 207篇 |
2001年 | 153篇 |
2000年 | 144篇 |
1999年 | 132篇 |
1998年 | 59篇 |
1997年 | 64篇 |
1996年 | 56篇 |
1995年 | 63篇 |
1994年 | 41篇 |
1993年 | 30篇 |
1992年 | 71篇 |
1991年 | 92篇 |
1990年 | 64篇 |
1989年 | 97篇 |
1988年 | 93篇 |
1987年 | 97篇 |
1986年 | 61篇 |
1985年 | 71篇 |
1984年 | 51篇 |
1983年 | 35篇 |
1982年 | 33篇 |
1979年 | 44篇 |
1978年 | 26篇 |
1977年 | 26篇 |
1975年 | 30篇 |
1974年 | 29篇 |
1973年 | 41篇 |
1972年 | 30篇 |
1971年 | 29篇 |
1970年 | 27篇 |
1969年 | 27篇 |
排序方式: 共有4711条查询结果,搜索用时 31 毫秒
81.
Psychiatric Quarterly - For centuries, attempting a successful rehabilitation of youth with antisocial behaviors has challenged juvenile justice systems and society. More recently, advances in... 相似文献
82.
Testing associations between cannabis use and subcortical volumes in two large population‐based samples 下载免费PDF全文
Nathan A. Gillespie Michael C. Neale Timothy C. Bates Lisa T. Eyler Christine Fennema‐Notestine Jasmin Vassileva Michael J. Lyons Elizabeth C. Prom‐Wormley Katie L. McMahon Paul M. Thompson Greig de Zubicaray Ian B. Hickie John J. McGrath Lachlan T. Strike Miguel E. Rentería Matthew S. Panizzon Nicholas G. Martin Carol E. Franz Margaret J. Wright 《Addiction (Abingdon, England)》2018,113(9):1661-1672
83.
Jeffrey L. Jackson Steven Asch Carol Bates 《Journal of general internal medicine》2018,33(12):2015-2021
84.
85.
86.
87.
Signal transduction by the platelet Fc receptor 总被引:6,自引:1,他引:6
We have evaluated the mechanism by which crosslinking human platelet Fc receptor (FcR) for IgG triggers platelet aggregation and the platelet release reaction. Platelet FcR was crosslinked by incubating purified human platelets with anti-FcRII monoclonal antibody and F(ab')2 anti- mouse Ig. The resultant [Ca2+]i increase, monitored by Fura-2 and measured in the absence of extracellular Ca2+, reached a peak of 750 +/- 50 nmol/L. The effects of cyclooxygenase inhibitors, aspirin and indomethacin, and a phospholipase A2 inhibitor, dibromoacetophenone, were examined. Regardless of the inhibitor, at least 25% of the [Ca2+]i increase remained. Thrombin (0.2 U/mL) stimulated an immediate [Ca2+]i increase that reached 1.95 +/- 0.8 mumol/L. The [Ca2+]i increase generated by thrombin was only slightly reduced by these inhibitors. Crosslinking the FcRII of platelets resulted in a fivefold increase in the production of [3H]inositol phosphates, (IP) which, in the absence of extracellular Ca2+ was insensitive to aspirin. The activation of a [Ca2+]i increase along with the measured increases in IP indicate that FcRII crosslinking leads to the activation of phospholipase C (PLC). In contrast to thrombin, platelet activation via FcRII depends to a large extent on arachidonic acid metabolites. However, neither cyclooxygenase nor phospholipase A2 inhibitors completely blocked FcRII-stimulated [Ca2+]i increase. These observations led us to propose that crosslinking of platelet FcRII initially activates PLC. 相似文献
88.
Normal human platelets were shown to contain the enzyme dihydropteridine reductase. The enzyme was not found in a variety of other cells of hematogenous origin. Partial purification and kinetic and physical data indicated that the platelet enzyme is similar to that previously characterized from liver. Dihydropteridine reductase is important for the regeneration of tetrahydrobiopterin, a required cofactor in hydroxylation reactions involved in biogenic amine formation. The presence of the enzyme may indicate that some synthesis de novo of serotonin and/or catecholamines occurs in platelets, as opposed to a purely storage and transport function. In addition, screening for hyperphenylalaninemia due to dihydropteridine reductase deficiency may become feasible by assaying platelets for enzyme activity. 相似文献
89.
90.