首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   45548篇
  免费   4431篇
  国内免费   3659篇
耳鼻咽喉   387篇
儿科学   482篇
妇产科学   620篇
基础医学   5459篇
口腔科学   1000篇
临床医学   5973篇
内科学   6812篇
皮肤病学   513篇
神经病学   2372篇
特种医学   1714篇
外国民族医学   20篇
外科学   4694篇
综合类   7794篇
现状与发展   15篇
一般理论   6篇
预防医学   3079篇
眼科学   1225篇
药学   4652篇
  29篇
中国医学   2871篇
肿瘤学   3921篇
  2024年   223篇
  2023年   708篇
  2022年   1835篇
  2021年   2278篇
  2020年   1796篇
  2019年   1494篇
  2018年   1601篇
  2017年   1474篇
  2016年   1360篇
  2015年   2011篇
  2014年   2549篇
  2013年   2188篇
  2012年   3197篇
  2011年   3496篇
  2010年   2112篇
  2009年   1752篇
  2008年   2241篇
  2007年   2304篇
  2006年   2275篇
  2005年   2060篇
  2004年   1703篇
  2003年   1822篇
  2002年   1630篇
  2001年   1390篇
  2000年   1225篇
  1999年   1309篇
  1998年   883篇
  1997年   809篇
  1996年   636篇
  1995年   582篇
  1994年   511篇
  1993年   261篇
  1992年   348篇
  1991年   289篇
  1990年   271篇
  1989年   221篇
  1988年   213篇
  1987年   175篇
  1986年   147篇
  1985年   91篇
  1984年   76篇
  1983年   33篇
  1982年   18篇
  1981年   15篇
  1980年   14篇
  1979年   6篇
  1978年   2篇
  1970年   1篇
  1969年   1篇
  1964年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
By a double-labeling method combining the retrograde tracing of horseradish peroxidase and the immunocytochemical technique, serotonin-like immunoreactive neurons in the midbrain periaqueductal gray (PAG) and nucleus raphe dorsalis (DR) of the rat were observed to send projection fibers to the nucleus parafascicularis of the thalamus bilaterally with an ipsilateral dominance. These serotonin-containing projecting neurons were observed mainly at the middle-caudal levels of the ventrolateral subdivision of the PAG and less at the middle-rostral levels of the DR.  相似文献   
12.
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response.  相似文献   
13.
14.
15.
T&#;ljedal  I. -B.  Shi  C. L.  Rooth  P. 《Diabetologia》1994,37(2):S112-S116
Diabetologia - To test whether the transplantation of pancreatic islets affects their basic functions, collagenaseisolated mouse islets were inserted under the left renal capsule of recipient...  相似文献   
16.
17.
此文全面论述了先进医学技术给传统医学伦理的医患关系模式、医生义务论、生命认识论、资源分配论等诸多方面带来的巨大冲击,并由此提出先进医学技术发展应遵循的伦理规则。  相似文献   
18.
Q P Ma  Y S Shi  J S Han 《Brain research》1992,583(1-2):292-295
Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop.  相似文献   
19.
D Z Shi 《中华妇产科杂志》1992,27(2):70-2, 123
To investigate the relationship between intrauterine infection and IUGR, the following studies have been carried out: (1) measurement of specific antibodies of Toxoplasma (Toxo) and Cytomegalovirus (CMV) in the umbilical serum samples from 30 cases of IUGR with 26 normal newborn infants as controls; (2) follow-up exam on 14 positive cases in 17-25 months. The results showed that in 30 IUGR cases 14 were found to have Toxo and CMV infection, with an incidence significantly higher than that in the control group. One third of the infected patients were found to have retarded growth afterbirth and 63.63% of them appeared to have an increase in BAEP. This suggested that regular follow-up is indicated in these cases.  相似文献   
20.
For investigating the effect of acupuncture on ischemic arrhythmia and its mech-anism, adult albino rats with ligated anterior descending branch of coronary artery as experimentalmodel were treated with or without acupuncture, and others with imitative operation but without bothcoronary artery ligation and acupuncture treatment were used as control. It was found in acupuncturegroup that the fibrillation-liability of ischemic myocardium was efficiently decreased, the affinity ofAch-M receptors on membranes of ischemic myocardium was markedly increased, and the tolerance ofischemic myocardium to atropine was elevated in the experiment of atropine inducing fibrillation.These results indicate that acupuncture may play a therapeutic role on ischemic arrhythmia throughactivating the activity of muscarine-like receptors of cholinergic nervous system.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号