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   1840984篇
  免费   133958篇
  国内免费   3145篇
耳鼻咽喉   25942篇
儿科学   61268篇
妇产科学   52223篇
基础医学   273021篇
口腔科学   52052篇
临床医学   160216篇
内科学   357481篇
皮肤病学   39768篇
神经病学   139348篇
特种医学   70688篇
外国民族医学   429篇
外科学   281668篇
综合类   39075篇
现状与发展   3篇
一般理论   436篇
预防医学   135091篇
眼科学   42541篇
药学   140359篇
  4篇
中国医学   4501篇
肿瘤学   101973篇
  2018年   18153篇
  2016年   15576篇
  2015年   17742篇
  2014年   24453篇
  2013年   37040篇
  2012年   50194篇
  2011年   53352篇
  2010年   31540篇
  2009年   29685篇
  2008年   50969篇
  2007年   54962篇
  2006年   56037篇
  2005年   53959篇
  2004年   52334篇
  2003年   50526篇
  2002年   49456篇
  2001年   86469篇
  2000年   88481篇
  1999年   74391篇
  1998年   20635篇
  1997年   18136篇
  1996年   18564篇
  1995年   17527篇
  1994年   16593篇
  1993年   15245篇
  1992年   59239篇
  1991年   58326篇
  1990年   57348篇
  1989年   56128篇
  1988年   52066篇
  1987年   50640篇
  1986年   48353篇
  1985年   45876篇
  1984年   34117篇
  1983年   29399篇
  1982年   17060篇
  1981年   15127篇
  1979年   31907篇
  1978年   22407篇
  1977年   19327篇
  1976年   18267篇
  1975年   20111篇
  1974年   23664篇
  1973年   22741篇
  1972年   21551篇
  1971年   20113篇
  1970年   18986篇
  1969年   18017篇
  1968年   16832篇
  1967年   14845篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
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   
74.
75.
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   
76.
77.
78.
79.
Context Withania somnifera (L.) Dunal is traditionally used for treating various ailments, but lacks scientific evaluation.

Objective This study evaluates Withania somnifera (WS) for its effect on platelet activity and inflammatory enzymes.

Materials and methods Aqueous and ethanolic (1:1) leaf extracts were subjected to in vitro indirect haemolytic activity using Naja naja venom, human platelet aggregation was quantified for lipid peroxidation using arachidonic acid (AA) as agonist and 5-lipoxygenase (5-LOX) levels were determined using standard spectrometric assays. Further, molecular docking was performed by the ligand fit method using molegro software package (Molegro ApS, Aarhus, Denmark).

Results The study found that aqueous and ethanol extracts have very negligible effect (15%) with an IC50 value of 13.8?mg/mL on PLA2 from Naja naja venom. Further, extracts of WS also had very little effect (18%) with an IC50 value of 16.6?mg/mL on malondialdehyde (MDA) formation. However, a 65% inhibition of 5-LOX with an IC50 value of 0.92?mg/mL was observed in 1:1 ethanol extracts. The same was evident from SAR model with the active ingredient withaferin A binding predominantly on Phe 77, Tyr 98, Arg 99, Asp 164, Leu 168, Ser 382, Arg 395, Tyr 396 and Tyr 614 with an atomic contact energy value of??128.96 compared to standard phenidone (?103.61). Thus, the current study validates the application of WS for inflammatory diseases.

Conclusion This study reveals the inhibitory potential of W. somnifera on inflammatory enzymes and platelet aggregation. Thus, WS can serve as a newer, safer and affordable medicine for inflammatory diseases.  相似文献   
80.
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