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   2174篇
  免费   151篇
  国内免费   58篇
耳鼻咽喉   23篇
儿科学   93篇
妇产科学   30篇
基础医学   263篇
口腔科学   62篇
临床医学   221篇
内科学   433篇
皮肤病学   59篇
神经病学   170篇
特种医学   339篇
外科学   159篇
综合类   47篇
预防医学   189篇
眼科学   57篇
药学   152篇
中国医学   2篇
肿瘤学   84篇
  2023年   10篇
  2021年   28篇
  2020年   20篇
  2019年   22篇
  2018年   32篇
  2017年   13篇
  2016年   18篇
  2015年   31篇
  2014年   44篇
  2013年   67篇
  2012年   63篇
  2011年   72篇
  2010年   61篇
  2009年   78篇
  2008年   61篇
  2007年   84篇
  2006年   72篇
  2005年   68篇
  2004年   48篇
  2003年   46篇
  2002年   50篇
  2001年   41篇
  2000年   51篇
  1999年   43篇
  1998年   83篇
  1997年   90篇
  1996年   116篇
  1995年   68篇
  1994年   67篇
  1993年   56篇
  1992年   45篇
  1991年   36篇
  1990年   45篇
  1989年   57篇
  1988年   58篇
  1987年   57篇
  1986年   63篇
  1985年   66篇
  1984年   26篇
  1983年   25篇
  1982年   27篇
  1981年   18篇
  1980年   17篇
  1979年   24篇
  1978年   18篇
  1977年   20篇
  1976年   23篇
  1975年   17篇
  1973年   13篇
  1968年   10篇
排序方式: 共有2383条查询结果,搜索用时 25 毫秒
11.
12.
13.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  相似文献   
14.
15.
Mediators of pulmonary injury induced by inhalation of bacterial endotoxin   总被引:4,自引:0,他引:4  
The purpose of this study has been to further define the pathophysiologic aspects of lung injury caused by the inhalation of endotoxin (LPS) using the morphometric approach to identify mediators that influence distal lung structure and function. Hamsters were divided into 3 groups 24 h prior to low dose LPS inhalation exposure (4 micrograms/m3 for 5 h): (1) pretreated with cobra venom factor to deplete complement in vivo, (2) pretreated with indomethacin to block prostaglandin production, and (3) untreated control group. Both pretreatments abolished LPS-induced decreases in lung volume as well as increases in capillary PMN and platelets seen in untreated control animals. Neither pretreatment had any effect on the LPS-induced decreases of other capillary leukocytes. Similarly, both methods of pretreatment failed to block increases in cellular interstitium of distal capillary septa induced with LPS alone. LPS provoked changes in capillary endothelium, especially seen as an increase in numerical density of endothelial pinocytotic vesicles. Decomplementation failed to alter this increase, but indomethacin pretreatment blocked the effect. Neither treatment had any effect on their size. Low dose LPS inhalation also altered pulmonary capillary permeability to a 125I-BSA probe, which was found in significantly greater amounts in LPS-exposed lungs than in those of saline aerosol control lungs, but was not present in the air space as evidenced by negligible counts in bronchoalveolar lavages. It is evident that endotoxin on the epithelial side of the air-blood barrier leads to changes on the other side of that barrier.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
16.
Isokinetic, shoulder rotational strength was evaluated in 26 high school baseball pitchers before the start of spring practice. Using the Cybex II (Cybex, Division of Lumex, Inc., Ronkonkoma, NY), test data were gathered on the dominant and nondominant shoulders in the supine 90 degrees abducted test position (90 degrees AbTP) and the standing neutral test position (neutral TP). Tests were performed at 90 and 240 deg/sec. The HUMAC (Computer Sports Medicine, Inc., Flemington, NJ) computer system was used to analyze data. Means and standard deviations for peak torque, total work, peak torque to body weight ratios, and agonist/antagonist ratios are presented. Comparison of dominant to non-dominant sides and 90 degrees AbTP to neutral TP values are reported. Peak torque and total work values for the throwing side internal rotators were significantly higher than the nonthrowing side in all tests. Pitching side external rotators failed to show this dominance. External/internal rotation ratios for peak torque and total work were significantly lower on the pitching side, suggesting a relative imbalance of cuff musculature compared to the nonpitching shoulder. Significant differences existed between data gathered in the two different test positions. In the 90 degrees AbTP, external rotation peak torque and total work values and external/internal rotation peak torque and total work ratios were higher than the equivalent values gathered in the neutral TP. Internal rotation peak torque and total work values tended to be higher in the neutral TP than in the 90 degrees AbTP.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
17.
The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.  相似文献   
18.
Birnholz  JC 《Radiology》1986,158(3):805-807
Ultrasound (US) can be used to visualize vertebral segments, suggesting a quantitative means of studying vertebral column growth in utero and thus a means of detecting developmental abnormalities. US images of the lumbar spine were obtained in 128 clinically normal fetuses between the gestational age of 11 through 41 weeks. A large-aperture, dynamically focused US system capable of regional magnification was used. Average lumbar spacing was calculated from distance between centrums of at least four lumbar bodies. The average distance between lumbar centrums increased nearly linearly throughout the second and third trimesters (r2 = 0.98). Enhanced anatomic display implies new capabilities for recognizing developmental abnormalities antenatally.  相似文献   
19.
20.
Male genital oedema can be defined as swelling or the appearance of swelling of the scrotum and/or the penile shaft and prepuce. Despite the various causes of genital oedema reported in the published work, a concise approach to the evaluation and management has not been sufficiently addressed.  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