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   1697篇
  免费   88篇
  国内免费   31篇
耳鼻咽喉   6篇
儿科学   69篇
妇产科学   18篇
基础医学   227篇
口腔科学   39篇
临床医学   149篇
内科学   322篇
皮肤病学   29篇
神经病学   74篇
特种医学   176篇
外科学   223篇
综合类   150篇
预防医学   95篇
眼科学   22篇
药学   122篇
  1篇
中国医学   15篇
肿瘤学   79篇
  2024年   4篇
  2023年   16篇
  2022年   37篇
  2021年   65篇
  2020年   27篇
  2019年   40篇
  2018年   48篇
  2017年   38篇
  2016年   48篇
  2015年   37篇
  2014年   52篇
  2013年   93篇
  2012年   73篇
  2011年   83篇
  2010年   71篇
  2009年   62篇
  2008年   97篇
  2007年   97篇
  2006年   83篇
  2005年   68篇
  2004年   83篇
  2003年   58篇
  2002年   46篇
  2001年   26篇
  2000年   22篇
  1999年   19篇
  1998年   47篇
  1997年   39篇
  1996年   43篇
  1995年   25篇
  1994年   21篇
  1993年   23篇
  1992年   12篇
  1991年   8篇
  1990年   11篇
  1989年   24篇
  1988年   19篇
  1987年   16篇
  1986年   23篇
  1985年   18篇
  1984年   5篇
  1983年   5篇
  1982年   18篇
  1981年   9篇
  1980年   12篇
  1978年   7篇
  1977年   9篇
  1976年   9篇
  1975年   7篇
  1953年   2篇
排序方式: 共有1816条查询结果,搜索用时 15 毫秒
91.
1. Magnolol is an active component of Magnolia officinalis. It is 1000-times more potent than α-tocopherol in inhibiting lipid peroxidation in rat heart mitochondira. In the present study, the in vivo antiarrhythmic and anti-ischaemic effects of magnolol in coronary ligated rats were investigated. 2. Male Sprague-Dawley rats were anaesthetized with urethane. Magnolol, at dosages of 10?7, 10?8 and 10?9 g/kg, was adminstered intravenously 15 min before ligation of the coronary artery. 3. The incidence and duration of ventricular tachycardia and ventricular fibrillation during 30 min coronary ligation were significantly reduced by magnolol. Ventricular arrhythmias during 10 min reperfusion after the relief of coronary ligation were also reduced. 4. In rats subjected to 4h coronary ligation, 10?7 and 10?8 g/kg magnolol significantly reduced infarct size. 5. We conclude that magnolol may protect the myocardium against ischaemic injury and suppress ventricular arrhythmia during ischaemia and reperfusion.  相似文献   
92.
谷氨酸脱羧酶抑制剂L-苹果酸对小鼠学习记忆的影响   总被引:5,自引:0,他引:5  
周红宇  郑国统  张士善 《药学学报》1996,31(12):897-900
跳台法和Y迷宫法试验表明,小鼠po L-苹果酸600mg·kg-1连续5d后对记忆的获得、巩固和再现均有明显的改善作用,并能促进空间辨别学习能力;L-苹果酸改善记忆的作用能被NMDA受体拮抗剂氯胺酮所拮抗。脑内游离氨基酸测定显示,L-苹果酸可明显降低小鼠脑内GABA水平,提高Glu/GABA比值。实验结果表明,脑内GABA水平下降,Glu/GABA比值升高对学习记忆有正性调节作用。  相似文献   
93.

Background

The sudden increase in incidence and magnitude of mine blast injuries prompted us to highlight the problem and its management.

Methods

The cases of mine blast injuries occurring during mining and demining in a particular geographical area were analysed. Total 27 cases of mine blast injuries occurred during mining or demining operations in a period of 13 months.

Results

Various body regions were involved in the mine blast injuries but the main brunt was borne by feet and legs followed by multiple body regions due to splinters. 14 patients underwent below knee (BK) amputation while 4 patients required through knee (TK) amputations. The effect of blast was so severe that most of the cases required 2 to 5 times wound debridements. The initial aggressive debridement / open stump amputation saved the limb and life of all patients.

Conclusion

A mine blast causes extensive injuries and psychological trauma. Management is needed urgently, surgery is difficult, and amputation is often inevitable. Maximum lives and limbs can be saved with aggressive debridement, repeated inspections and dressings under anaesthesia and definitive closure at optimum time.Key Words: Amputation, Antipersonnel mine, Crush syndrome, Debridements, Mine blast injury, Secondary missiles, Shrapenels  相似文献   
94.
The authors report the direct, microvascular repair of a right coronary artery transected during reoperation fOr complications of arterial switch operation (ASO) in a 3 month-old child. This is the first documented use of direct microsurgical anastamosis in the repair of an infant's transected coronary artery. Deviation from standard coronary bypass graft repair was permitted by vessel characteristics, as well as close collaboration between plastic surgery and cardiac surgery services. Patency of repair was confirmed intraoperatively with Doppler ultrasound and through postoperative echocardiograms documenting stable right ventricular function. This case highlights the benefit of a multidisciplinary approach to an emergent clinical problem using microsurgical techniques.  相似文献   
95.
96.
The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.  相似文献   
97.
98.
Thoracic computed tomographic (CT) scans of 250 patients with newly diagnosed or recurrent lymphoma revealed thoracic wall involvement in 24 patients (11 with Hodgkin disease, 13 with non-Hodgkin lymphoma). Thoracic wall involvement occurred without contiguous mediastinal or parenchymal involvement in 17 patients. Of these, 13 patients had masses beneath the pectoralis muscles or within the breast, and four had masses arising from the ribs. Five additional patients had mediastinal masses with thymic involvement and parasternal extension through the thoracic wall. Pulmonary parenchymal lymphoma with thoracic wall invasion was noted in the remaining two patients. In five of nine patients receiving radiation therapy, treatment plans were modified by CT demonstration of thoracic wall lymphoma.  相似文献   
99.
100.
Decreased septal wall thickening in patients with left bundle branch block   总被引:2,自引:0,他引:2  
OBJECTIVES: Septal wall motion abnormalities are frequently observed in patients with left bundle branch block (LBBB). However, septal wall thickening in LBBB patients has not been thoroughly evaluated. METHODS AND RESULTS: To investigate the relationship between septal wall motion and wall thickening, we studied 31 normal control subjects, 24 LBBB patients with normal wall motion (LBBB-NWM), and 24 LBBB patients with septal dyssynchrony (LBBB-SDS), all with a low likelihood (<15%) of coronary artery disease. The septal and lateral quadrants of the left ventricle were analyzed in stress 8-frame gated technetium 99m sestamibi tomograms. The percent wall thickening was calculated by use of a 25-segment polar map with the p-FAST software program by two independent methods: the regional count density increase from end diastole to end systole (CD method) and the geometric increase in the distance between the 50% thresholded endocardial and epicardial borders from end diastole to end systole (GD method). In addition, the ratio of septal/lateral percent wall thickening was calculated. The relative septal wall thickening in the entire LBBB population was decreased as compared with the normal control subjects (0.35 +/- 0.37 vs 0.81 +/- 0.17, P <.001). Decreased wall thickening was observed in not only LBBB-SDS patients but also to a lesser degree in LBBB-NWM patients (0.12 +/- 0.35, P <.001; 0.57 +/- 0.24, P =.005, respectively). This abnormality was most apparent when the CD method was used. CONCLUSIONS: Septal wall thickening is decreased in patients with LBBB even with normal wall motion. LBBB per se may compromise septal wall thickening, and dyssynchronous wall motion results in further deterioration of wall thickening.  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