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   1924篇
  免费   109篇
  国内免费   7篇
耳鼻咽喉   33篇
儿科学   88篇
妇产科学   33篇
基础医学   185篇
口腔科学   52篇
临床医学   166篇
内科学   452篇
皮肤病学   50篇
神经病学   93篇
特种医学   59篇
外科学   273篇
综合类   73篇
预防医学   91篇
眼科学   66篇
药学   166篇
中国医学   15篇
肿瘤学   145篇
  2023年   20篇
  2022年   46篇
  2021年   103篇
  2020年   46篇
  2019年   59篇
  2018年   73篇
  2017年   34篇
  2016年   72篇
  2015年   55篇
  2014年   100篇
  2013年   91篇
  2012年   122篇
  2011年   142篇
  2010年   89篇
  2009年   67篇
  2008年   101篇
  2007年   104篇
  2006年   93篇
  2005年   66篇
  2004年   69篇
  2003年   60篇
  2002年   48篇
  2001年   43篇
  2000年   30篇
  1999年   34篇
  1998年   14篇
  1997年   13篇
  1996年   10篇
  1995年   11篇
  1994年   8篇
  1993年   5篇
  1992年   19篇
  1991年   17篇
  1990年   18篇
  1989年   19篇
  1988年   21篇
  1987年   17篇
  1986年   18篇
  1985年   13篇
  1984年   10篇
  1983年   12篇
  1982年   2篇
  1981年   2篇
  1979年   12篇
  1978年   9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2040条查询结果,搜索用时 46 毫秒
1.
2.
3.
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   
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.
BACKGROUND AND AIM OF STUDY: Cardioplegic arrest remains the method of choice for myocardial protection in cardiac surgery. Caffeic acid phenethyl ester (CAPE) prevents lipid peroxidation induced by ischemia-reperfusion injury and has a potent antioxidant property. We investigated the advantages of CAPE supplemented cardioplegic solution (St. Thomas' Hospital cardioplegic solution No.: 2) on the antioxidant defense system of myocardium against ischemia-reperfusion injury. MATERIAL AND METHODS: Isolated rat hearts were mounted on a nonrecirculating type of Langendorff apparatus. The hearts were arrested for 60 min with cardioplegic solution given at 20-min intervals and then reperfused for 15 min. The hearts were divided into three groups. Cold saline (0.9%, 4 degrees C) in group 1, St. Thomas' Hospital solution in group 2 and CAPE added St. Thomas' Hospital solution in group 3 were used as the cardioplegic solution. Krebs-Henseleit buffer solution was used for reperfusion. The tissues were examined biochemically for oxidative stress. RESULTS: Significant differences among the three groups existed in tissue myeloperoxidase (MPO), catalase (CAT), Na+-K+ ATPase activity and in the concentrations of malonydealdehyde (MDA) and 3-nitrotyrosine (3-NT). Group 2 showed significant changes in MPO (P = 0.04), Na+-K+ ATPase enzyme activity (P = 0.02) and the levels of MDA (P = 0.004) and 3-NT (P = 0.01) in comparison with group 1. Group 3 efficiently reduced MDA levels (P = 0.004) and also led to significant decrease in levels of MPO (P = 0.006), 3-NT (P = 0.01) and Na+-K+ ATPase activity (P = 0.01) and increase in the level of CAT (P = 0.004) in comparison with group 1. Significant changes were also found in the levels of MDA (P = 0.03), MPO (P = 0.04) and CAT (P = 0.009) in comparison between groups 2 and 3. CONCLUSIONS: We demonstrated that the administration of CAPE into cardioplegic solutions improves the antioxidant defense system of rat heart during the ischemia-reperfusion injury.  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.
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