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   339073篇
  免费   44994篇
  国内免费   2075篇
耳鼻咽喉   4956篇
儿科学   8852篇
妇产科学   6758篇
基础医学   34748篇
口腔科学   9354篇
临床医学   49872篇
内科学   75160篇
皮肤病学   6475篇
神经病学   35110篇
特种医学   11582篇
外国民族医学   11篇
外科学   54391篇
综合类   3549篇
现状与发展   40篇
一般理论   318篇
预防医学   33618篇
眼科学   8487篇
药学   17711篇
  6篇
中国医学   365篇
肿瘤学   24779篇
  2024年   846篇
  2023年   6021篇
  2022年   3338篇
  2021年   7784篇
  2020年   8093篇
  2019年   7013篇
  2018年   12301篇
  2017年   11259篇
  2016年   12226篇
  2015年   13249篇
  2014年   18200篇
  2013年   22911篇
  2012年   21125篇
  2011年   21806篇
  2010年   16757篇
  2009年   17741篇
  2008年   19542篇
  2007年   19377篇
  2006年   20349篇
  2005年   18959篇
  2004年   17344篇
  2003年   15922篇
  2002年   14881篇
  2001年   3781篇
  2000年   2630篇
  1999年   3843篇
  1998年   4960篇
  1997年   4320篇
  1996年   3987篇
  1995年   3643篇
  1994年   2739篇
  1993年   2430篇
  1992年   1957篇
  1991年   1735篇
  1990年   1458篇
  1989年   1441篇
  1988年   1433篇
  1987年   1287篇
  1986年   1278篇
  1985年   1231篇
  1984年   1437篇
  1983年   1390篇
  1982年   1573篇
  1981年   1494篇
  1980年   1256篇
  1979年   760篇
  1978年   859篇
  1977年   742篇
  1976年   662篇
  1974年   538篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo.  相似文献   
84.
85.
86.
Experiments were performed to determine the effect of pin channel preparation with standard and reduction speed handpieces, and pin seating by hand and with motor drive. The greatest retention was achieved by preparation with a standard handpiece at 6000 rpm, and manual pin placement with a hand driver. The most consistent retention values were achieved using the reduction handpiece. All preparation and placement combinations examined produced a clinically acceptable result.  相似文献   
87.
D. W. Barnes, D. A. Sirbasku & G. H. Sato, (eds.): Cell culture methods for molecular and cell biology. P. M. Gootman (ed.): Developmental neurobiology of the autonomic nervous system. M. Sandler, C. Feuerstein, B. Scatton (eds.): Neurotransmitter interactions in the basal ganglia. Harry M. Zimmerman (ed). Progress in neuropathology. M. Yahr & K. J. Bergmann (eds.): Parkinson's disease. G. Bock & M. O'Connor (eds.): Selective neuronal death. H. Julia Hannay (ed.): Experimental techniques in human neuropsychology. D. Papakostopoulos, S. Butler, I. Martin (eds.): Clinical and experimental neuropsychophysiology J. C. Rothwell: Control of human voluntary movement.  相似文献   
88.
89.
In a study of rock music preferences, listening/watching behavior, and views on destructive rock lyrics, 894 adolescents in grades 9 through 12 in rural, urban, suburban public, and metropolitan parochial schools were administered a questionnaire. Demographic information on parents was also collected. It was found that 17.5% of the students were fans of rock music with lyrics that promote homicide, suicide, or satanic practices (HSSR). Loglinear and multiple regression analyses were used to analyze the data. Parents' marital status, student sex, race, and school environment (urban, rural, suburban, etc.) were found to be significant predictors of HSSR status. As compared with non-HSSR fans, the HSSR fans were more likely to have parents who were “Never married” or “Remarried” and less likely to have parents in the “married” category. The HSSR fans were more likely to be male, white, and enrolled in urban schools but not parochial schools than expected; HSSR status also significantly predicted other music-related attitudes and behaviors. The HSSR fans reported liking both the sound and the lyrics of rock music more often than did non-HSSR fans, as did females and urban students. The HSSR fans more often felt that children under 10 years of age should be allowed to listen to HSSR lyrics, and they more frequently expressed the conviction that HSSR music does not affect adolescents' homicidal or self-destructive behavior. The HSSR fans and females reported more nearly complete knowledge of lyrics than did non-HSSR fans and males. The HSSR fans reported that they watch more MTV than did any other group except rural students.  相似文献   
90.
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