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   258248篇
  免费   18505篇
  国内免费   1134篇
耳鼻咽喉   2890篇
儿科学   6708篇
妇产科学   4731篇
基础医学   33874篇
口腔科学   4783篇
临床医学   25951篇
内科学   54674篇
皮肤病学   3461篇
神经病学   24766篇
特种医学   8589篇
外国民族医学   11篇
外科学   39363篇
综合类   3625篇
一般理论   320篇
预防医学   22111篇
眼科学   6738篇
药学   17432篇
  6篇
中国医学   366篇
肿瘤学   17488篇
  2023年   1371篇
  2022年   2441篇
  2021年   5503篇
  2020年   3320篇
  2019年   5390篇
  2018年   6073篇
  2017年   4565篇
  2016年   5060篇
  2015年   5927篇
  2014年   8732篇
  2013年   11983篇
  2012年   18264篇
  2011年   19179篇
  2010年   10734篇
  2009年   9576篇
  2008年   16860篇
  2007年   17754篇
  2006年   17586篇
  2005年   17531篇
  2004年   16461篇
  2003年   15246篇
  2002年   14292篇
  2001年   2381篇
  2000年   1869篇
  1999年   2531篇
  1998年   3176篇
  1997年   2619篇
  1996年   2249篇
  1995年   2132篇
  1994年   1799篇
  1993年   1607篇
  1992年   1443篇
  1991年   1309篇
  1990年   1127篇
  1989年   1124篇
  1988年   1110篇
  1987年   1073篇
  1986年   1073篇
  1985年   1076篇
  1984年   1291篇
  1983年   1200篇
  1982年   1397篇
  1981年   1353篇
  1980年   1186篇
  1979年   768篇
  1978年   820篇
  1977年   697篇
  1976年   627篇
  1975年   511篇
  1974年   515篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
63.
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   
64.
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   
65.
66.
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   
67.
68.
69.
70.
The craft of surgery has always relied on the use of instruments. Innovations in surgery have paralleled innovations in instrumentation. Advances in surgical instrumentation continue today and have enabled huge strides in surgical procedures and outcomes during this generation. Computers and related technology are now changing the interface between the surgeon and the patient, and are poised to improve patient outcomes by enhancing the surgeon’s skills and training. The application of computer enhanced telemanipulators, or “robots”, may specifically enhance operations, for example Heller myotomy, that require good visualization and precise careful dissection of delicate structures. This review covers the pathophysiology of achalasia and its history of medical and surgical treatment, leading to modern robotic telesurgical approaches. Improvements in outcome from medical to standard surgical to robotic telesurgical approaches are discussed. Current operative technique for robotic telesurgical treatment of achalasia is described and the authors conclude with a glimpse of where, in the future, current research endeavors will lead us in the treatment of achalasia.  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