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   846351篇
  免费   52162篇
  国内免费   1721篇
耳鼻咽喉   10476篇
儿科学   25488篇
妇产科学   18634篇
基础医学   134771篇
口腔科学   18710篇
临床医学   82300篇
内科学   159306篇
皮肤病学   16308篇
神经病学   63442篇
特种医学   30271篇
外国民族医学   74篇
外科学   125155篇
综合类   12529篇
现状与发展   2篇
一般理论   473篇
预防医学   67964篇
眼科学   19860篇
药学   63745篇
  7篇
中国医学   1523篇
肿瘤学   49196篇
  2021年   10029篇
  2020年   6095篇
  2019年   9935篇
  2018年   12665篇
  2017年   9252篇
  2016年   10574篇
  2015年   12029篇
  2014年   16757篇
  2013年   24082篇
  2012年   35832篇
  2011年   38731篇
  2010年   21856篇
  2009年   19598篇
  2008年   34492篇
  2007年   37283篇
  2006年   36517篇
  2005年   35872篇
  2004年   34270篇
  2003年   32356篇
  2002年   30834篇
  2001年   26900篇
  2000年   27105篇
  1999年   23450篇
  1998年   9133篇
  1997年   7637篇
  1996年   7256篇
  1995年   6847篇
  1994年   6098篇
  1992年   17568篇
  1991年   18780篇
  1990年   18677篇
  1989年   18284篇
  1988年   16862篇
  1987年   16750篇
  1986年   15638篇
  1985年   15166篇
  1984年   11861篇
  1983年   10264篇
  1982年   6283篇
  1979年   10767篇
  1978年   7928篇
  1977年   6474篇
  1976年   6745篇
  1975年   7733篇
  1974年   8703篇
  1973年   8259篇
  1972年   7634篇
  1971年   7186篇
  1970年   6694篇
  1969年   6164篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The effect of localized hyperthermia on blood flow and cis-diamminedichloroplatinum(II) (CDDP) pharmacokinetics in 7,12-dimethylbenz[a]anthracene-induced mammary adenocarcinomas was studied. Blood flow was determined in rat tumors and normal tissue immediately and 1, 2, and 3 h after local hyperthermia treatment (43 degrees C, 1 h) as well as in unheated tumors of rats. The rate of blood flow in the tumor was increased 1.9 times at the end of treatment relative to control values and returned to the control values by 3 h after hyperthermia. Similarly, the rate of blood flow in the peripheral skin around the tumor immediately after hyperthermia was 2.2 times greater than that of unheated skin and returned to near normal values by 3 h after heating. Tumor-bearing rats received CDDP 1 h before, at the beginning of, at the end of, and 1 h after hyperthermia administration. The CDDP plasma concentration versus time profiles for rats did not vary statistically between treatment groups. Two h after CDDP administration, the mean tumor CDDP concentration of the rats which received drug at the beginning of hyperthermia was statistically greater (P less than 0.05) than tumor CDDP concentrations in rats which received drug at the end of heat treatment. The latter group was given CDDP when tumor blood flow was the greatest; however, mean tumor drug concentration was lowest of all the groups. The mean drug concentration in tumor tissues of rats which received drug 1 h after hyperthermia was comparable to rats which received drug at the beginning of hyperthermia. This suggests that drug delivery or uptake in tumors may be altered when local hyperthermia is administered concurrently or sequentially.  相似文献   
52.
This paper examines the effect of patient age, tumour grade and extent of surgery on the outcome of treatment of 278 patients with high grade malignant gliomas referred to the Queensland Radium Institute between 1980 and 1987. The aim was to determine whether the extent of surgical resection alters survival rates. The extent of surgery had no effect on survival except for those patients with grade 3 tumours in whom a total excision was possible. Those in whom only a biopsy was done did not have a worse prognosis. Grading was found to be of importance, as patients with grade 3 tumours had a better survival than those with grade 4 tumours. In grade 4 tumours, those under 30 years of age had a better survival than those over 30 years, whereas with grade 3 tumours there was a gradation of age effect (under 40 years best, then 40–49 years, and those 50 years and over doing worst).  相似文献   
53.
54.
55.
56.
This study examined electromyogram (EMG) and skin conductance level (SCL) as mediators of neuropsychological test performance of alcoholics. Alcoholics and controls with high EMG performed less well than low EMG subjects on 12 measures of neuropsychological performance. For SCL, the alcoholics and controls in the Low Group did not differ from those in the High Group on any measure. Analyses that used information intake (Low EMG and High SCL) and rejection (High EMG and Low SCL) information postures (IPs) demonstrated that the intake group outperformed the rejection group on 10 neuropsychological measures. Subjects with intake IPs reported more stimulation, concentration, and interest during the tasks than did subjects with rejection IPs. Results suggest that IPs can be used to identify alcoholics with neuropsychological deficits.  相似文献   
57.
58.
Fronto-ethmoidal mucocoeles: a histopathological analysis.   总被引:1,自引:0,他引:1  
From a series of 118 fronto-ethmoidal mucocoeles, 40 specimens have been submitted to detailed histological analysis. The frequency of each epithelial and sub-epithelial component is considered and reveals features which support a dynamic theory of bone resorption and formation rather than that of pressure erosion in the pathogenesis of mucocoeles.  相似文献   
59.
Facial reanimation after acoustic neuroma excision is currently accomplished using a variety of surgical techniques. A multi-institutional survey of patient perceptions of facial reanimation success was accomplished by mailing a questionnaire to 809 randomly selected members of the Acoustic Neuroma Association. Four hundred sixty patients who underwent 296 reanimation procedures responded. Facial to hypoglossal nerve anastomosis, tarsorrhaphy, and upper eyelid implants were most frequently performed. The patient's estimations of initial deficit, spontaneous recovery, and overall satisfaction with the reanimation procedures are discussed.  相似文献   
60.
Most authors consider the principal advantage of FG anastomoses (compared to microsurgical anastomoses) to be shorter operating time, reduced surgical trauma to oviduct stumps, and absence of tissue ischemia. These features promote reparative regeneration and decrease adhesion formation, resulting in complete recanalization of fallopian tubes. To date, the majority of work on FG is confined to the experimental development of surgical techniques. Investigations in reconstructive gynecological surgery are quite uncommon. The physical properties of FG and the positive results of available experimental studies suggest that further development of surgical techniques using FG in obstetrics and gynecology is worthwhile.  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