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   8769篇
  免费   923篇
  国内免费   17篇
耳鼻咽喉   88篇
儿科学   358篇
妇产科学   226篇
基础医学   1320篇
口腔科学   203篇
临床医学   943篇
内科学   1691篇
皮肤病学   109篇
神经病学   765篇
特种医学   588篇
外国民族医学   1篇
外科学   1028篇
综合类   237篇
一般理论   3篇
预防医学   794篇
眼科学   152篇
药学   731篇
中国医学   18篇
肿瘤学   454篇
  2021年   107篇
  2020年   63篇
  2019年   116篇
  2018年   131篇
  2017年   108篇
  2016年   87篇
  2015年   125篇
  2014年   191篇
  2013年   286篇
  2012年   342篇
  2011年   383篇
  2010年   210篇
  2009年   203篇
  2008年   320篇
  2007年   374篇
  2006年   355篇
  2005年   348篇
  2004年   313篇
  2003年   295篇
  2002年   283篇
  2001年   275篇
  2000年   275篇
  1999年   257篇
  1998年   204篇
  1997年   157篇
  1996年   148篇
  1995年   119篇
  1994年   130篇
  1993年   124篇
  1992年   223篇
  1991年   209篇
  1990年   232篇
  1989年   227篇
  1988年   190篇
  1987年   192篇
  1986年   157篇
  1985年   149篇
  1984年   134篇
  1983年   128篇
  1982年   72篇
  1981年   80篇
  1980年   58篇
  1979年   113篇
  1978年   88篇
  1977年   88篇
  1976年   101篇
  1975年   89篇
  1974年   77篇
  1973年   84篇
  1972年   82篇
排序方式: 共有9709条查询结果,搜索用时 35 毫秒
41.
The long-acting analogue of luteinizing hormone releasing hormone, D-Trp6-Pro9-NEt-LHRH (LHRHa), is effective in the short-term treatment of central precocious puberty. We report the results of two to four years of LHRHa therapy in 27 children with this disorder. Secondary sex characteristics regressed in most patients. Sex steroid levels and basal and LHRH-stimulated gonadotropin levels remained suppressed compared with pretreatment values. Linear growth rates decreased from 11.0 +/- 0.8 (SEM) cm/yr before treatment to 5.7 +/- 0.4 cm/yr at two years of treatment and 3.7 +/- 0.7 cm/yr at four years of treatment. Predicted heights by the Bayley-Pinneau method increased from 156.4 +/- 2.0 cm before treatment to 162.3 +/- 2.3 cm at two years and 163.4 +/- 2.4 cm at three years. Five patients treated for four years had a mean increase in predicted height of 5.5 cm. To date no adverse effects have been observed. However, the ultimate safety of this analogue is not known. We conclude that LHRHa appears to be an effective long-term therapy for central precocious puberty.  相似文献   
42.
43.
44.
A greenstick intercondylar fracture of the distal humerus occurred in a 14-year-old boy. The minimal displacement and stability of the injury allowed early range of motion with healing in an anatomic position and restoration of the preinjury arc of motion.  相似文献   
45.
46.
Within the Huntington's disease (HD) candidate region of 4p16.3, the D4S127 locus displays strong linkage disequilibrium with the defect and anchors a conserved haplotype found on many HD chromosomes. To isolate genes from this region we have applied the exon amplification technique to overlapping cosmids spanning D4S127. Here, we report the discovery of a new gene encoding a novel member of a family of protein kinases that specifically phosphorylate the activated forms of G protein-coupled receptors. Such kinases are thought to participate in desensitization of specific receptors, thereby blocking further signal transduction. This gene must now be carefully scrutinized to determine whether it might be involved in HD.  相似文献   
47.
The post-mortem diagnosis of acute myocardial ischaemia may be difficult to establish in the absence of morphological changes in the myocardium or recent coronary thrombosis. Ischaemic cell injury leads to potassium (K) efflux and sodium (Na) influx and, if the blood is still circulating, the K:Na ratio of the tissue falls. In this study, the K:Na ratio was measured by eluting the ions from samples of myocardium and assaying the eluate. The method yields similar results to those obtained by a previous method, in which myocardial samples were homogenized. The K:Na ratios on samples of horizontal slices through the heart were plotted on maps of the slices. A low K:Na ratio corresponded to, but extended beyond, areas where there was morphological evidence of ischaemia. The method is simple and may be of use in routine practice.  相似文献   
48.
49.
50.
The regulation of histamine-stimulated phosphoinositide turnover by histamine and phorbol esters was examined in intact DDT1 MF-2 cells grown in suspension culture. Histamine increased the incorporation of 32P into phosphatidylinositol (PI) in these cells, and this stimulation was inhibited by the H1 antagonist diphenhydramine but not by the H2 antagonist cimetidine. Pretreatment of cells with histamine or with phorbol 12-myristate 13-acetate (PMA) or other activators of protein kinase C induced a marked decrease in the subsequent stimulation by histamine. PMA, but not histamine, also decreased the ability of epinephrine to stimulate PI labelling through alpha 1-adrenoceptors. Thus, histamine appears to induce homologous desensitization of histamine H1 receptor-mediated PI turnover, whereas direct activation of protein kinase C in the absence of receptor occupancy by agonist induces nonspecific heterologous desensitization of both histamine H1- and alpha 1-adrenoceptor-mediated responses.  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