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   1049898篇
  免费   74570篇
  国内免费   2452篇
耳鼻咽喉   14827篇
儿科学   26178篇
妇产科学   25016篇
基础医学   151827篇
口腔科学   31237篇
临床医学   91850篇
内科学   204141篇
皮肤病学   23023篇
神经病学   81832篇
特种医学   43640篇
外国民族医学   79篇
外科学   167481篇
综合类   18826篇
现状与发展   4篇
一般理论   260篇
预防医学   68095篇
眼科学   24326篇
药学   83601篇
  3篇
中国医学   3592篇
肿瘤学   67082篇
  2021年   9852篇
  2019年   8771篇
  2018年   12451篇
  2017年   9878篇
  2016年   11507篇
  2015年   14267篇
  2014年   18345篇
  2013年   24830篇
  2012年   35013篇
  2011年   35604篇
  2010年   20860篇
  2009年   19525篇
  2008年   31878篇
  2007年   32687篇
  2006年   32682篇
  2005年   31149篇
  2004年   29545篇
  2003年   27925篇
  2002年   26829篇
  2001年   57108篇
  2000年   58753篇
  1999年   48661篇
  1998年   11559篇
  1997年   10075篇
  1996年   10064篇
  1995年   9331篇
  1994年   8639篇
  1993年   7898篇
  1992年   36107篇
  1991年   34487篇
  1990年   33275篇
  1989年   32302篇
  1988年   29385篇
  1987年   28620篇
  1986年   26561篇
  1985年   25438篇
  1984年   18051篇
  1983年   15299篇
  1982年   7920篇
  1979年   15976篇
  1978年   10735篇
  1977年   9148篇
  1976年   7983篇
  1975年   8730篇
  1974年   10584篇
  1973年   9955篇
  1972年   9453篇
  1971年   8935篇
  1970年   8494篇
  1969年   7974篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
62.
63.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  相似文献   
64.
65.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  相似文献   
66.
67.
68.
69.
70.
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