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   26828篇
  免费   2358篇
  国内免费   54篇
耳鼻咽喉   246篇
儿科学   747篇
妇产科学   513篇
基础医学   3616篇
口腔科学   929篇
临床医学   2766篇
内科学   5852篇
皮肤病学   276篇
神经病学   2624篇
特种医学   969篇
外国民族医学   1篇
外科学   3412篇
综合类   701篇
一般理论   23篇
预防医学   2499篇
眼科学   785篇
药学   1822篇
中国医学   12篇
肿瘤学   1447篇
  2022年   144篇
  2021年   378篇
  2020年   246篇
  2019年   392篇
  2018年   429篇
  2017年   360篇
  2016年   363篇
  2015年   432篇
  2014年   615篇
  2013年   1089篇
  2012年   1409篇
  2011年   1511篇
  2010年   800篇
  2009年   808篇
  2008年   1461篇
  2007年   1577篇
  2006年   1599篇
  2005年   1573篇
  2004年   1482篇
  2003年   1365篇
  2002年   1409篇
  2001年   545篇
  2000年   523篇
  1999年   506篇
  1998年   365篇
  1997年   330篇
  1996年   303篇
  1995年   301篇
  1994年   259篇
  1993年   243篇
  1992年   398篇
  1991年   347篇
  1990年   396篇
  1989年   352篇
  1988年   376篇
  1987年   327篇
  1986年   309篇
  1985年   330篇
  1984年   274篇
  1983年   254篇
  1982年   271篇
  1981年   257篇
  1980年   203篇
  1979年   243篇
  1978年   195篇
  1977年   159篇
  1976年   137篇
  1974年   157篇
  1973年   161篇
  1972年   152篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Gas-producing diabetic foot infections are limb-threatening emergencies commonly encountered by foot and ankle surgeons. Appropriate treatment includes aggressive surgical debridement, parenteral antibiotics, and postoperative wound care. The authors present a unique case of a patient who refused treatment for a deep-space gas-producing infection, resulting in autoamputation of the foot. The authors also discuss the confusion surrounding the definition of gas gangrene.  相似文献   
82.
Background: The gastric bypass operation has evolved since 1966 when it was first introduced. The purpose of this study was to determine the present state of gastric bypass by consensus among the members of the American Society for Bariatric Surgery (ASBS). Method: A questionnaire was sent to all members of the ASBS. Forty-three percent responded reporting over 41,200 cases. Results: Results were analyzed by using χ2 tests with a null hypothesis. Surgeons agreed on several technical aspects, preferring a vertical to a horizontal stapleline; estimating, rather than measuring, the pouch volume at an average of 22 cc. Few surgeons divide the short gastric vessels, and only 25% of surgeons polled use a restrictive ring or band proximal to the gastroenterostomy. Most surgeons calibrate the gastroenterostomy, reporting a preferred average diameter of 12.3 cm. There was no consensus regarding forming the gastroenterostomy, 58% preferring hand-sewn and 42% stapled anastomoses. There was no consensus regarding dividing the gastric pouch from the bypassed stomach: Conclusion: The preferred gastric bypass is vertical, with the pouch estimated at 20-25 cc, and the gastroenterostomy calibrated at 12 mm diameter. The short gastric vessels need not be divided, and restrictive bands or rings are not preferred. This technique of gastric bypass should be used as the control procedure when modifications are tested in future trials. Randomized prospective studies are suggested to probe the benefits of division of the stomach pouch from the bypassed stomach.  相似文献   
83.
84.
The rare combination of spinal and intracranial meningeal hemangiopericytomas in the same patient is reported. The coexistence of cerebral and spinal meningiomas of all histological subtypes is distinctly uncommon with only nine cases found in the literature.  相似文献   
85.
86.
We describe a case of preeclampsia with the HELLP (Haemolysis, Elevated Liver enzymes, Low Platelets) syndrome and highlight the delayed diagnosis due to its nonspecific presentation. This syndrome is associated with significant maternal and perinatal mortality and morbidity and we discuss the importance of early recognition of the condition, aggressive management and a multidisciplinary approach.  相似文献   
87.
Subcutaneous melatonin implants were administered to castrated hand-reared male red deer (Cervus elaphus) during a 63 d period in spring, after which effects on voluntary feed intake (VFI), rumen pool size, rumen capacity (i.e. volume) and heart rate were measured on four occasions, evenly spread over a 12-month period, with the deer individually fed indoors on a diet of lucerne (Medicago sativa) chaff. Blood samples for hormone determinations were taken at intervals throughout the study. Day-time plasma melatonin concentration was approximately 5 pg/ml in control animals, whereas during melatonin administration it increased to 60-150 pg/ml and declined to 30 pg/ml by 142 d after the last implantation. Melatonin administration markedly depressed plasma prolactin concentration during the period of implantation, but thereafter plasma prolactin concentration rose in the treated animals during autumn and winter, whilst it declined in control animals over this period. VFI, rumen pool size and heart rate in control animals attained highest values in summer and lowest values in winter, showing a pronounced seasonal cycle. Melatonin administration depressed all these values in late spring and summer and increased all the values in autumn and winter, relative to control animals, and appeared to move the cycles by approximately 6 months. Melatonin-treated animals showed maximum values for all these measurements during winter. The castrated male deer showed little seasonal change in live weight, which was not affected by melatonin administration. The findings support the view that melatonin probably mediates the effect of daylength on digestive function in red deer. Rumen capacity remained relatively constant throughout the year, but rumen pool size as a proportion of rumen capacity increased with increasing VFI.  相似文献   
88.
Ten patients with DSM-III-R obsessive-compulsive disorder (OCD) underwent the desipramine (DMI) growth hormone (GH) stimulation test as well as the dexamethasone suppression test (DST). The results were compared with the responses in a group of matched healthy controls. The GH response to DMI did not differ between patients and controls and 9 of 10 patients showed cortisol suppression in response to dexamethasone. The data suggest that neither alpha 2 adrenergic dysfunction nor DST non-suppression are features of primary OCD.  相似文献   
89.
90.
The presence of depression was evaluated in a cross-section of 50 outpatients with dementia using the self-rated Geriatric Depression Scale and the clinician-rated Cornell Depression Scale. Impaired insight, as manifested by unawareness of dementia, correlated with dementia severity and discriminated a group of patients in whom the self-rated scale failed to show evidence of depression. Discrepancy between the two types of scales occurred among mildly as well as moderately demented patients when insight was impaired. Recognition of this discrepancy suggests that reliance on self-ratings may underestimate the presence and degree of depression among patients with dementia.  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