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   117289篇
  免费   8724篇
  国内免费   412篇
耳鼻咽喉   1453篇
儿科学   2935篇
妇产科学   1877篇
基础医学   16505篇
口腔科学   2590篇
临床医学   11686篇
内科学   24795篇
皮肤病学   2141篇
神经病学   12155篇
特种医学   5096篇
外国民族医学   16篇
外科学   17002篇
综合类   1362篇
一般理论   75篇
预防医学   8953篇
眼科学   2002篇
药学   7940篇
中国医学   133篇
肿瘤学   7709篇
  2023年   613篇
  2022年   1165篇
  2021年   2361篇
  2020年   1450篇
  2019年   2151篇
  2018年   2658篇
  2017年   1974篇
  2016年   2384篇
  2015年   2752篇
  2014年   3602篇
  2013年   4722篇
  2012年   7310篇
  2011年   7372篇
  2010年   4318篇
  2009年   3980篇
  2008年   6575篇
  2007年   7056篇
  2006年   6611篇
  2005年   6577篇
  2004年   6125篇
  2003年   5524篇
  2002年   5472篇
  2001年   2469篇
  2000年   2372篇
  1999年   2165篇
  1998年   1420篇
  1997年   1164篇
  1996年   963篇
  1995年   943篇
  1994年   819篇
  1993年   758篇
  1992年   1476篇
  1991年   1369篇
  1990年   1332篇
  1989年   1270篇
  1988年   1126篇
  1987年   1058篇
  1986年   1061篇
  1985年   1049篇
  1984年   856篇
  1983年   736篇
  1982年   658篇
  1981年   544篇
  1980年   470篇
  1979年   666篇
  1978年   517篇
  1977年   457篇
  1975年   434篇
  1974年   458篇
  1973年   442篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
111.
In an in vitro study, 10 gallbladders of adult pigs and 6 gallbladders of lambs, all removed immediately after slaughtering, were stimulated in a water bath by electric means to induce active contraction. Gallbladder emptying was followed by ultrasonography employing five measurement procedures: (1) gallbladder width, (2) longitudinal planimetry, (3) transverse planimetry, (4) ellipsoid method, and (5) sum of cylinders method. In an in vivo investigation, gallbladder emptying of 30 volunteers (12 healthy subjects, 18 diabetics) was evaluated in the same way after ingestion of a fatty meal. Gallbladder width was found to be unsuitable to estimate the decrease in gallbladder volume due to a nonlinear relation of the parameters. Longitudinal planimetry tended to be less valid than transverse planimetry in assessing gallbladder volume reduction. The most valid estimation of gallbladder volume decreases was obtained by the two three-dimensional procedures. However, in neither in vitro nor in vivo could a significant difference between the sum of cylinders method and the ellipsoid method in determining relative volume reduction be established. We conclude that a three-dimensional measurement procedure should be used for valid assessments of gallbladder motility. However, according to our data there is no advantage in using the time-consuming sum of cylinders method compared to the simple ellipsoid method.  相似文献   
112.
113.
114.
Fiber-reinforced resin composites (FRCs) have been used to make frameworks to support particulate resin composite veneers in the replacement of missing teeth. Both prosthetic laboratory-fabricated and chairside-fabricated approaches have been used with varying degrees of success. The chairside FRC fixed partial denture has been mainly used for anterior tooth replacement where the emphasis is on esthetics rather than withstanding occlusal load. This article focuses on the use of this technology in the chairside replacement of premolars. The concept of using a prefabricated framework is described in detail. This approach allows for the efficient delivery of a consistently made chairside prosthesis. This is in contrast with the time-consuming and less consistent result of FRC framework fabrication directly in the mouth. The goal for this concept is to use a premade framework finalized by the provider at chairside to provide medium- to long-term posterior tooth replacement, with minimal abutment tooth reduction.  相似文献   
115.
A case of esthesioneuroblastoma with an unusual clinical and radiographic presentation is reported. The presenting symptoms as well as the computed tomographic examination were compatible with a primary intracranial mass.  相似文献   
116.
BACKGROUND: The dopamine transporter (DAT) is known to be a key regulator of dopamine, and recent studies of genetics, treatment, and imaging have highlighted the role of DAT in attention-deficit/hyperactivity disorder (ADHD). The findings of in vivo neuroimaging of DAT in ADHD have been somewhat discrepant, however. METHOD: Dopamine transporter binding was measured using a highly selective ligand (C-11 altropane) and positron emission tomography (PET). The sample consisted of 47 well-characterized, treatment-na?ve, nonsmoking, non-comorbid adults with and without ADHD. Additionally, control subjects had few symptoms of ADHD. RESULTS: Results showed significantly increased DAT binding in the right caudate in adults with ADHD compared with matched control subjects without this disorder. CONCLUSIONS: These results confirm abnormal DAT binding in the striatum of adults with ADHD and provide further support that dysregulation of DAT may be an important component of the pathophysiology of ADHD.  相似文献   
117.
118.
A régime for the care of far advanced cancer patients is elaborated.The following considerations in therapy are discussed: the psychologic approach; nursing care; bedsores; ulcers; odors; discharges; the peculiarities of abdominal cancer; fistulae from hollow viscera; hemorrhage; intractable pain; palliative operations.The importance of treating the exact cause of the discomfort rather than loading the patient with narcotics, is emphasized.  相似文献   
119.
120.
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