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   20700篇
  免费   1372篇
  国内免费   56篇
耳鼻咽喉   127篇
儿科学   447篇
妇产科学   272篇
基础医学   2758篇
口腔科学   325篇
临床医学   2573篇
内科学   3632篇
皮肤病学   198篇
神经病学   1822篇
特种医学   722篇
外科学   2852篇
综合类   235篇
一般理论   28篇
预防医学   2684篇
眼科学   443篇
药学   1606篇
中国医学   35篇
肿瘤学   1369篇
  2024年   20篇
  2023年   139篇
  2022年   240篇
  2021年   494篇
  2020年   314篇
  2019年   442篇
  2018年   515篇
  2017年   395篇
  2016年   433篇
  2015年   585篇
  2014年   744篇
  2013年   979篇
  2012年   1655篇
  2011年   1683篇
  2010年   959篇
  2009年   893篇
  2008年   1467篇
  2007年   1609篇
  2006年   1459篇
  2005年   1453篇
  2004年   1421篇
  2003年   1341篇
  2002年   1158篇
  2001年   157篇
  2000年   114篇
  1999年   172篇
  1998年   225篇
  1997年   153篇
  1996年   138篇
  1995年   104篇
  1994年   111篇
  1993年   88篇
  1992年   50篇
  1991年   45篇
  1990年   33篇
  1989年   38篇
  1988年   27篇
  1987年   34篇
  1986年   30篇
  1985年   28篇
  1984年   27篇
  1983年   28篇
  1982年   23篇
  1981年   25篇
  1980年   20篇
  1979年   4篇
  1978年   9篇
  1977年   7篇
  1976年   14篇
  1975年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
The purpose of this laboratory study was to assess the value of refractometry in identifying the contents of a variety of opioid-containing solutions. A hand-held refractometer was used to document the refraction produced by the undiluted contents of alfentanil, fentanyl, morphine, sufentanil ampoules and by solutions of Ringer’s lactate, 0.9% saline, 3.3% dextrose in 0.3% saline, and distilled water. Each opioid was then serially diluted in serial 1:2, 1:4, and 1:8 dilutions in each of these solutions and the refractions of each determined. Based on this information, blinded identification of various diluted opioid solutions was attempted. Refractometer values for undiluted fentanyl and sufentanil were identical with those for distilled water. Those for undiluted alfentanil and morphine were almost identical with each other and with 1:2 and 1:4 dilutions of either drug in Ringer’s lactate or 0.9% saline. We conclude that refractometry is an unreliable screening method to detect tampering with opioid solutions.  相似文献   
94.
The cerebral representation of space depends on the integration of many different sensory inputs. The vestibular system provides one such input and its dysfunction can cause profound spatial disorientation. Using positron emission tomography (PET), we measured regional cerebral perfusion with various vestibular stimulations to map central vestibular projections and to investigate the cerebral basis of spatial disorientation. We showed that the temporoparietal cortex, the insula, the putamen, and the anterior cingulate cortex are the cerebral projections of the vestibular system in man and that the spatial disorientation caused by unilateral vestibular stimulation is associated with their asymmetric activation.  相似文献   
95.
96.
Summary Forearm bone mineral density (BMD) was measured at proximal and distal sites by 125I single photon absorptiometry (SPA) and by dual energy X-ray absorptiometry (DXA) in 67 consecutive subjects, aged 18–75 years. Correlations and regression equations between these two techniques were determined. All forearm measurements were significantly correlated with each other (r=0.599–0.926; P0.0001). Although SPA and DXA correct for fat in different ways, we found similar correlation and regression equations in women with body mass index measurements above and below the mean. In addition, forearm measurements by both techniques were moderately correlated with vertebral spine and hip BMD. We conclude that overall, SPA forearm measurements in a population can be calibrated to DXA measurements if necessary, and that DXA forearm measurements are as predictive of the remainder of the skeleton as SPA measurements.  相似文献   
97.
COX-inhibiting nitric oxide donators (CINODs) are a new class of drugs in development for the treatment of acute and chronic pain. They comprise a COX-inhibiting moiety linked to a nitric-oxide-donating component and are designed to provide an innovative mechanism of action of balanced COX inhibition and controlled nitric oxide donation. Through these pathways, CINODs should provide analgesic and anti-inflammatory efficacy, while offering gastrointestinal safety through the tissue-protective effects of nitric oxide donation. AZD3582 [4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propanoate] is the first agent in the CINOD class to enter extensive clinical development. Pre-clinical studies demonstrate that AZD3582 has a superior gastrointestinal safety profile to naproxen, while demonstrating analgesic and anti-inflammatory efficacy. In healthy human volunteers, AZD3582 caused little gastrointestinal damage compared with equimolar doses of naproxen. Studies to evaluate the longer-term gastrointestinal safety of AZD3582, alongside its efficacy in alleviating chronic and acute pain, are ongoing.  相似文献   
98.
99.
100.
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