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   2048259篇
  免费   149363篇
  国内免费   3139篇
耳鼻咽喉   29570篇
儿科学   64160篇
妇产科学   54313篇
基础医学   290224篇
口腔科学   58026篇
临床医学   178174篇
内科学   405904篇
皮肤病学   43842篇
神经病学   159687篇
特种医学   81253篇
外国民族医学   725篇
外科学   322870篇
综合类   42093篇
现状与发展   2篇
一般理论   578篇
预防医学   147032篇
眼科学   46036篇
药学   155152篇
  5篇
中国医学   4206篇
肿瘤学   116909篇
  2018年   20165篇
  2017年   15475篇
  2016年   17099篇
  2015年   19329篇
  2014年   26754篇
  2013年   40293篇
  2012年   55159篇
  2011年   58108篇
  2010年   34730篇
  2009年   33202篇
  2008年   56241篇
  2007年   59859篇
  2006年   60724篇
  2005年   58833篇
  2004年   57373篇
  2003年   55474篇
  2002年   54483篇
  2001年   107549篇
  2000年   111624篇
  1999年   94242篇
  1998年   23898篇
  1997年   21357篇
  1996年   21796篇
  1995年   20508篇
  1994年   19230篇
  1993年   17769篇
  1992年   73344篇
  1991年   71174篇
  1990年   69075篇
  1989年   66559篇
  1988年   61034篇
  1987年   59781篇
  1986年   55744篇
  1985年   53497篇
  1984年   39177篇
  1983年   33056篇
  1982年   18260篇
  1981年   16331篇
  1979年   34916篇
  1978年   23838篇
  1977年   20423篇
  1976年   18416篇
  1975年   20119篇
  1974年   23817篇
  1973年   22737篇
  1972年   21216篇
  1971年   19683篇
  1970年   18645篇
  1969年   17171篇
  1968年   15568篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
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   
42.
43.
44.
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   
45.
46.
47.
48.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
49.
50.
Jahn  P. 《Der Onkologe》2020,26(11):1040-1046
Die Onkologie - Die Pflegepersonaluntergrenzen als rote Linien zur Abgrenzung einer gefährlichen Pflegepraxis sind nicht geeignet, die dringend benötigte Trendwende einzuleiten und...  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