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   2439篇
  免费   257篇
  国内免费   50篇
耳鼻咽喉   26篇
儿科学   114篇
妇产科学   20篇
基础医学   245篇
口腔科学   78篇
临床医学   230篇
内科学   510篇
皮肤病学   63篇
神经病学   117篇
特种医学   205篇
外科学   378篇
综合类   131篇
一般理论   1篇
预防医学   198篇
眼科学   30篇
药学   210篇
中国医学   4篇
肿瘤学   186篇
  2023年   18篇
  2021年   44篇
  2020年   28篇
  2019年   33篇
  2018年   41篇
  2017年   51篇
  2016年   58篇
  2015年   42篇
  2014年   101篇
  2013年   118篇
  2012年   88篇
  2011年   95篇
  2010年   113篇
  2009年   108篇
  2008年   83篇
  2007年   133篇
  2006年   115篇
  2005年   74篇
  2004年   74篇
  2003年   57篇
  2002年   49篇
  2001年   72篇
  2000年   55篇
  1999年   73篇
  1998年   94篇
  1997年   84篇
  1996年   67篇
  1995年   65篇
  1994年   60篇
  1993年   54篇
  1992年   46篇
  1991年   25篇
  1990年   37篇
  1989年   45篇
  1988年   35篇
  1987年   28篇
  1986年   28篇
  1985年   39篇
  1984年   28篇
  1983年   30篇
  1982年   21篇
  1980年   16篇
  1979年   13篇
  1978年   13篇
  1977年   14篇
  1976年   22篇
  1975年   16篇
  1971年   12篇
  1970年   12篇
  1968年   12篇
排序方式: 共有2746条查询结果,搜索用时 93 毫秒
1.
Haaga  JR; Beale  SM 《Radiology》1986,161(3):829-830
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).  相似文献   
2.
3.
Although it has been demonstrated that many of the behavioral responses to psychomotor stimulants are gender dependent and hormonally sensitive, few studies have examined the possibility that the estrous cycle interacts with drug reinforcement in laboratory animals. The present experiment assessed the effect of the estrous cycle on two aspects of cocaine self-administration behavior: the breaking point on a progressive ratio (PR) schedule and the rate of cocaine intake on a fixed ratio one (FR1) schedule. On the PR schedule, the first lever response produced a drug infusion. Subsequent response requirements escalated with each injection until the behavior extinguished. Breaking points were defined as the final ratio completed. On a FR1 schedule, the estrous cycle had no effect on the rate of drug intake. On a PR schedule, female rats reached higher breaking points during estrus than during other stages of the estrous cycle. Furthermore, female rats displayed higher breaking points than male rats. It appears that the estrous cycle influences an animal's motivation to self-administer cocaine.  相似文献   
4.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  相似文献   
5.
Birnie  D.  H.  Vickers  L.  E.  Hillis  W.  S.  杨海涛 《世界核心医学期刊文摘》2006,2(1):49-50
目的:探讨抗人热休克蛋白60或抗分枝杆菌热休克蛋白65抗体是否能够预测因急性心源性胸痛入院的患者一年预后不良。设计:前瞻性观察研究。地点:教学医院。患者:连续588例急诊收治的疑似急性心源性胸痛患者。主要观察指标:测定入院后晨起血样的抗人热休克蛋白60和抗分枝杆菌热休克蛋白65效价。出院后终点为冠心病死亡、非致死性心肌梗死、冠状动脉搭桥术、经皮穿刺腔内冠状动脉成形术、血管造影或因心脏缺血性胸痛加重再次入院。  相似文献   
6.
7.
8.
In an attempt to define the hemodynamic and radiographic parameters of normal erectile function 6 patients 20 to 41 years old (mean age 30.3 years) with erectile dysfunction that spontaneously resolved after a comprehensive evaluation were reviewed. The results included normal hormonal assays, normal penile biothesiometry and normal penile brachial index. The sleep tumescence and rigidity tracings were abnormal according to the criteria that sleep erections occur every 90 minutes, are associated with penile rigidity of greater than 550 gm. plus an increase in penile circumference of greater than 1.5 cm. and last longer than 15 minutes. High resolution ultrasonography, pulse wave Doppler ultrasound, dynamic pharmacocavernosometry and dynamic cavernosography were performed. After testing the patients were informed that no organic abnormalities had been detected. No medical or surgical treatment was given. The hemodynamic values are presented as suggested normal parameters: maintenance rate (mean 11 +/- 3 cc per minute), initial decompression rate (mean 59 +/- 17 mm. Hg/30 seconds) and radiographic findings (visualization of the cavernous, external pudendal and deep dorsal veins during pharmacocavernosography, performed at intracorporeal pressures of 100 mm. Hg). All 6 patients had maintenance rates of greater than 5 cc per minute. Of these 6 patients 5 had initial decompression rates of greater than 48 mm. Hg/30 seconds and 4 had 5-minute, post-infusion steady state values of less than 50 mm. Hg, criteria that have been used to define corporovenous dysfunction.  相似文献   
9.
This paper documents the type, frequency and duration of complications associated with regional anaesthesia of the maxillary nerve via the greater palatine canal in a series of 101 patients treated in the Oral Surgery Department, United Dental Hospital of Sydney.  相似文献   
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