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   1816篇
  免费   109篇
  国内免费   9篇
耳鼻咽喉   31篇
儿科学   82篇
妇产科学   23篇
基础医学   193篇
口腔科学   66篇
临床医学   134篇
内科学   387篇
皮肤病学   54篇
神经病学   114篇
特种医学   50篇
外科学   257篇
综合类   71篇
现状与发展   1篇
一般理论   1篇
预防医学   68篇
眼科学   65篇
药学   159篇
中国医学   13篇
肿瘤学   165篇
  2023年   25篇
  2022年   36篇
  2021年   86篇
  2020年   45篇
  2019年   57篇
  2018年   63篇
  2017年   27篇
  2016年   59篇
  2015年   50篇
  2014年   88篇
  2013年   87篇
  2012年   113篇
  2011年   146篇
  2010年   74篇
  2009年   62篇
  2008年   88篇
  2007年   106篇
  2006年   94篇
  2005年   65篇
  2004年   70篇
  2003年   60篇
  2002年   45篇
  2001年   44篇
  2000年   28篇
  1999年   31篇
  1998年   21篇
  1997年   13篇
  1996年   12篇
  1995年   12篇
  1994年   9篇
  1993年   5篇
  1992年   20篇
  1991年   17篇
  1990年   19篇
  1989年   20篇
  1988年   21篇
  1987年   18篇
  1986年   17篇
  1985年   12篇
  1984年   10篇
  1983年   12篇
  1982年   2篇
  1981年   3篇
  1979年   12篇
  1978年   7篇
  1977年   7篇
  1976年   3篇
  1973年   5篇
  1970年   2篇
  1959年   1篇
排序方式: 共有1934条查询结果,搜索用时 31 毫秒
1.
2.
Teratomas are true neoplasms composed of tissues from all three germinal layers and may exhibit variable levels of maturity. They have an unknown origin and eccentric microscopic appearance. Teratomas arising from the oral cavity are rare in the newborn; only 22 cases have been reported in the literature. We describe a female neonate with an oral teratoma originating from the tongue that was successfully treated with surgery.  相似文献   
3.
4.
5.
Four patients with mild to moderate obstructive sleep apnea were monitored first in the supine posture to establish a diagnosis of obstructive sleep apnea (apnea indices 33, 12, 22, 36). A second polysomnogram, obtained while the patients slept in the lateral posture, showed a dramatic decrease in apnea (apnea indices 5, 0, 0.2, and 0) and snoring. Each patient had an enlarged uvula, which moved to the side in the lateral posture. We conclude that sleeping in the lateral posture may be therapeutic in some patients with obstructive sleep apneas.  相似文献   
6.
High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.   相似文献   
7.
Twenty patients with nodulocystic acne were randomly allocated to one of two treatment schedules: 1) Tetracycline 500 mg or 2) Tab. Gugulipid (equivalent to 25 mg guggulsterone). Both were taken twice daily for 3 months, and both produced a progressive reduction in the lesions in the majority of patients. With tetracycline, the percentage reduction in the inflammatory lesions was 65.2% as compared to 68% with gugulipid; on comparison, this difference was statistically insignificant (P>0.05). Follow-up at 3 months showed a relapse in 4 cases on tetracyline and 2 cases on gugulipid. An interesting observation was that the patients with oily faces responded remarkably better to gugulipid.  相似文献   
8.
Management of post-cholecystectomy bile duct strictures can be complex.Traditional treatment has been surgical reconstruction. In recent years endoscopic stenting has been successful in a selected subgroup of patients with iatrogenic bile duct strictures. Adequate information about long-term results of endoscopic stenting as definite treatment for such strictures is still awaited. Surgery is a reliable and time-tested method and results of numerous studies show its long-term success in relieving biliary obstruction with minimal morbidity.  相似文献   
9.
10.
Norepinephrine triggers release of glial ATP to increase postsynaptic efficacy   总被引:10,自引:0,他引:10  
Glial cells actively participate in synaptic transmission. They clear molecules from the synaptic cleft, receive signals from neurons and, in turn, release molecules that can modulate signaling between neuronal elements. Whether glial-derived transmitters can contribute to enduring changes in postsynaptic efficacy, however, remains to be established. In rat hypothalamic paraventricular nucleus, we demonstrate an increase in the amplitude of miniature excitatory postsynaptic currents in response to norepinephrine that requires the release of ATP from glial cells. The increase in quantal efficacy, which likely results from an insertion of AMPA receptors, is secondary to the activation of P2X(7) receptors, an increase in postsynaptic calcium and the activation of phosphatidylinositol 3-kinase. The gliotransmitter ATP, therefore, contributes directly to the regulation of postsynaptic efficacy at glutamatergic synapses in the CNS.  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