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   11336篇
  免费   1114篇
  国内免费   39篇
耳鼻咽喉   175篇
儿科学   349篇
妇产科学   212篇
基础医学   1466篇
口腔科学   97篇
临床医学   1411篇
内科学   2622篇
皮肤病学   111篇
神经病学   1123篇
特种医学   368篇
外科学   1896篇
综合类   124篇
一般理论   4篇
预防医学   898篇
眼科学   399篇
药学   594篇
中国医学   7篇
肿瘤学   633篇
  2023年   120篇
  2022年   213篇
  2021年   441篇
  2020年   224篇
  2019年   355篇
  2018年   432篇
  2017年   315篇
  2016年   347篇
  2015年   371篇
  2014年   477篇
  2013年   608篇
  2012年   923篇
  2011年   897篇
  2010年   466篇
  2009年   429篇
  2008年   678篇
  2007年   613篇
  2006年   576篇
  2005年   565篇
  2004年   505篇
  2003年   411篇
  2002年   364篇
  2001年   113篇
  2000年   89篇
  1999年   84篇
  1998年   70篇
  1997年   54篇
  1994年   36篇
  1992年   81篇
  1991年   57篇
  1990年   67篇
  1989年   56篇
  1988年   68篇
  1987年   92篇
  1986年   79篇
  1985年   71篇
  1984年   66篇
  1983年   61篇
  1982年   63篇
  1981年   52篇
  1980年   35篇
  1979年   57篇
  1978年   44篇
  1976年   42篇
  1975年   35篇
  1974年   47篇
  1973年   40篇
  1972年   45篇
  1971年   35篇
  1969年   35篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
A case of subserosal gastric neurilemmoma is hereby presented. This reported case is unique in its clinical presentation including the appearance of acute abdomen and fever subsequent to unremarkable and uneventful upper gastrointestinal endoscopy. The tendency of neurilemmoma to cause mucosal ulceration with fistula formation probably led to this clinical presentation. The role of computed tomography in establishing diagnosis of exogastric tumor is emphasized.  相似文献   
42.
P A Nathan  R C Keniston  L D Myers  K D Meadows 《JAMA》1992,268(6):787; author reply 787-787; author reply 780
  相似文献   
43.
44.
Background: Opioids are commonly used in conjunction with sedative drugs to provide anesthesia. Previous studies have shown that opioids reduce the clinical requirements of sedatives needed to provide adequate anesthesia. Processed electroencephalographic parameters, such as the Bispectral Index (BIS; Aspect Medical Systems, Newton, MA) and Auditory Evoked Potential Index (AAI; Alaris Medical Systems, San Diego, CA), can be used intraoperatively to assess the depth of sedation. The aim of this study was to characterize how the addition of opioids sufficient to change the clinical level of sedation influenced the BIS and AAI.

Methods: Twenty-four adult volunteers received a target-controlled infusion of remifentanil (0-15 ng/ml) and inhaled sevoflurane (0-6 vol%) at various target concentration pairs. After reaching pseudo-steady state drug levels, the modified Observer's Assessment of Alertness/Sedation score, BIS, and AAI were measured at each target concentration pair. Response surface pharmacodynamic interaction models were built using the pooled data for each pharmacodynamic endpoint.

Results: Response surface models adequately characterized all pharmacodynamic endpoints. Despite the fact that sevoflurane-remifentanil interactions were strongly synergistic for clinical sedation, BIS and AAI were minimally affected by the addition of remifentanil to sevoflurane anesthetics.  相似文献   

45.
The aim of this study was to evaluate corneal innervation in soft contact lens wearers using the Tomey Confoscan confocal microscope (40x/0.75 objective lens). Three distinct age- and sex-matched subject groups were involved, including extended soft (hydrogel and silicone-hydrogel) contact lens wearers, overnight soft (hydrogel) contact lens wearers, and non contact lens wearers. A number of variables were objectively measured, subjectively evaluated, or graded in order to investigate the distribution and morphology of corneal nerves. For most of the evaluated parameters, no statistically significant differences were found. However, qualitative observations showed noticeable differences in corneal nerve appearance among the different subject groups; the degree of corneal oedema was suggested as the main causative factor. In conclusion, neither the short-term (overnight wear) nor the long-term (12-month extended wear) soft contact lens wear appeared to affect the morphology and/or distribution of corneal nerves as viewed with confocal microscopy.  相似文献   
46.
47.
Pradeep J Nathan  Andrew H Kemp  Ben J Harrison 《Neuropsychopharmacology》2003,28(7):1383; author reply 1384-1383; author reply 1385
  相似文献   
48.
One of the side effects of cisplatinum-based chemotherapy is the impairment of spermatogenic function. In order to understand the mechanisms responsible for this side effect, the present study examined the short- and long-term effects of five daily injections of 2 mg/kg cisplatinum upon the functional normality of Leydig cells and Sertoli cells in intact adult rats, and their relationship with the status of spermatogenesis. Results of the present study demonstrate that cisplatinum treatment resulted in a progressive but reversible loss of germ cells from the seminiferous epithelium. Although testicular testosterone contents reduced transiently after the adminisration of cisplatinum, these testosterone levels are otherwise sufficient to support complete spermatogenesis. Thus, the cisplatinum-induced germinal regression cannot be accounted for by hypoandrogenism. The testicular ABP contents of the drug-treated rats remained unchanged during the treatment period, decreased transiently 30 days after the treatment, and returned to normal 120 days after treatment. A decrease in epididymal ABP content was also noted 10 and 30 days after the drug treatment. These observations suggest that Sertoli cell functions were affected by cisplatinum treatment. The effects of cisplatinum upon Sertoli cells were further demonstrated by the dose-dependent suppression of the production of ABP, lactate, and estradiol in cultured Sertoli cells. In addition, cisplatinum administration resulted in a reversible decrease in pituitary weights and an irreversible decrease in seminal vesicle weights. These results further demonstrate the toxic effects of cisplatinum upon various aspects of the male reproductive system.  相似文献   
49.
SYNOPSIS
These experiments investigate thermographic patterns in the posterior cervical/thoracic (PCT) region of 530headache patients and 30 headache/injury-free volunteers. The study examines: The longitudinal persistence ofProximal and Distal patterns; three distinct midline patterns (PCT I, II, and III); and their correlation with diagnosis,injury, and pain.
Twenty-four (80%) of 30 randomly selected subjects displayed unchanged Proximal patterns at the meanobservation period of 5.5 months. PCT pattern fluctuations occurred in 13/30 (43.3%) subjects. The distinctivenessof each subject's Proximal and Distal patterns was verified by blind calling of thermogram pairs. Patternpersistence was validated with alcohol spray-Patterns were identical regardless of using a 0.5°C or 1.0°Ctemperature setting. Temperature settings of 1.0°C yielded more distinct Proximal and Distal patterns.
Chi square analysis determined that there was no significant difference in the number of PCT III patterns in theexperimental or control groups.
In conclusion, it appears that Proximal and Distal Patterns may be consistent over time and individually unique,but that PCT patterns fluctuate and, therefore, do not correlate with chronic headaches.  相似文献   
50.
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