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   3588篇
  免费   264篇
  国内免费   2篇
耳鼻咽喉   88篇
儿科学   97篇
妇产科学   58篇
基础医学   356篇
口腔科学   40篇
临床医学   386篇
内科学   890篇
皮肤病学   95篇
神经病学   371篇
特种医学   102篇
外科学   408篇
综合类   60篇
一般理论   4篇
预防医学   462篇
眼科学   99篇
药学   175篇
中国医学   3篇
肿瘤学   160篇
  2023年   12篇
  2022年   23篇
  2021年   57篇
  2020年   52篇
  2019年   71篇
  2018年   74篇
  2017年   43篇
  2016年   66篇
  2015年   85篇
  2014年   136篇
  2013年   181篇
  2012年   285篇
  2011年   261篇
  2010年   197篇
  2009年   141篇
  2008年   208篇
  2007年   244篇
  2006年   253篇
  2005年   233篇
  2004年   238篇
  2003年   225篇
  2002年   186篇
  2001年   29篇
  2000年   34篇
  1999年   39篇
  1998年   46篇
  1997年   41篇
  1996年   52篇
  1995年   37篇
  1994年   25篇
  1993年   25篇
  1992年   17篇
  1991年   17篇
  1990年   19篇
  1989年   13篇
  1988年   15篇
  1987年   15篇
  1986年   13篇
  1985年   12篇
  1984年   18篇
  1983年   15篇
  1982年   16篇
  1981年   13篇
  1980年   10篇
  1979年   7篇
  1977年   6篇
  1976年   5篇
  1975年   7篇
  1974年   7篇
  1971年   4篇
排序方式: 共有3854条查询结果,搜索用时 15 毫秒
11.
Swimmer     
McMahon  Ted 《JAMA》2004,292(13):1529
  相似文献   
12.
13.
14.
One hundred three consecutive patients referred for treatment of chronic pelvic pain underwent MMPI testing, and 60 had diagnostic laparoscopy. A physical cause for the pain was found in 45 (75%) of the 60. However, three fourths (34) of patients with an organic cause for the pain also had evidence of psychopathology on the MMPI. Reassurance and education as to the role of stress in causing or exacerbating pain complaints appeared helpful. Most patients improve without major surgery.  相似文献   
15.
16.
Pseudopregnant, pregnant, and ovariectomized rabbits were utilized to study hormonal mediation of uterine epithelial surface negativity and glycocalyx morphology, and to seek local effects of blastocysts at sites of implantation. A loss of surface negativity [polycationic ferritin (PCF) binding] by day 6 of pregnancy or pseudopregnancy was noted, accompanied by alterations in epithelial glycocalyx. Uteri from estrous animals, or ovariectomized animals receiving oil or estradiol injections, bound PCF and exhibited a “globular” glycocalyx. Uteri from day 6 pseudopregnant or pregnant animals, or ovariectomized animals receiving progesterone injections, did not bind PCF or exhibit a globular glycocalyx. Both PCF binding and the globular character of the epithelial glycocalyx were sensitive to neuraminidase and trypsin treatment, suggesting sialoglycoprotein contribution to surface negativity. Implanting blastocysts had no detectable local effect on surface negativity, but did induce local reduction of epithelial glycocalyx at sites of implantation. Results of this study suggest that uterine epithelial glycocalyx alterations during the preimplantation period reflect a general response to prosgesterone stimulation, primarily qualtitative in nature, related to the acquisition of receptivity to ovo-implantation.  相似文献   
17.
Spaced training is generally more effective than massed training for learning and memory, but the molecular mechanisms underlying this trial spacing effect remain poorly characterized. One potential molecular basis for the trial spacing effect is the differential modulation, by distinct temporal patterns of neuronal activity, of protein synthesis-dependent processes that contribute to the expression of specific forms of synaptic plasticity in the mammalian brain. Long-term potentiation (LTP) is a type of synaptic modification that may be important for certain forms of memory storage in the mammalian brain. To explore the role of protein synthesis in the trial spacing effect, we assessed the protein synthesis dependence of hippocampal LTP induced by 100-Hz tetraburst stimulation delivered to mouse hippocampal slices in either a temporally massed (20-s interburst interval) or spaced (5-min interburst interval) fashion. To extend our studies to the behavioral level, we trained mice in fear conditioning using either a massed or spaced training protocol and examined the sensitivity of long-term memory to protein synthesis inhibition. Larger LTP was induced by spaced stimulation in hippocampal slices. This improvement of synaptic potentiation following temporally spaced synaptic stimulation in slices was attenuated by bath application of an inhibitor of protein synthesis. Further, the maintenance of LTP induced by spaced synaptic stimulation was more sensitive to disruption by anisomycin than the maintenance of LTP elicited following massed stimulation. Temporally spaced behavioral training improved long-term memory for contextual but not for cued fear conditioning, and this enhancement of memory for contextual fear was also protein synthesis dependent. Our data reveal that altering the temporal spacing of synaptic stimulation and behavioral training improved hippocampal LTP and enhanced contextual long-term memory. From a broad perspective, these results suggest that the recruitment of protein synthesis-dependent processes important for long-term memory and for long-lasting forms of LTP can be modulated by the temporal profiles of behavioral training and synaptic stimulation.  相似文献   
18.
19.
20.
Summary Two patients presenting with malignant meningitis resulting from small-cell carcinoma of the lung and with lymphoblastic leukemia, respectively, were treated by intrathecal administration of etoposide. In both cases, this treatment was well tolerated and produced relief of the central nervous system symptoms. Pharmacokinetic data showed that cerebrospinal fluid drug levels of up to 5.2 g/ml were achieved, which were considerably higher than those obtained after i.v. administration of high-dose etoposide.  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