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   1353150篇
  免费   101640篇
  国内免费   7171篇
耳鼻咽喉   18749篇
儿科学   43223篇
妇产科学   38988篇
基础医学   196336篇
口腔科学   36919篇
临床医学   118130篇
内科学   263501篇
皮肤病学   27298篇
神经病学   103407篇
特种医学   52689篇
外国民族医学   398篇
外科学   205045篇
综合类   39359篇
现状与发展   15篇
一般理论   311篇
预防医学   97991篇
眼科学   31149篇
药学   106223篇
  81篇
中国医学   6806篇
肿瘤学   75343篇
  2021年   11416篇
  2018年   14549篇
  2017年   11384篇
  2016年   12361篇
  2015年   15138篇
  2014年   20264篇
  2013年   28349篇
  2012年   39544篇
  2011年   42290篇
  2010年   25310篇
  2009年   23249篇
  2008年   39303篇
  2007年   42096篇
  2006年   42246篇
  2005年   41510篇
  2004年   39049篇
  2003年   37793篇
  2002年   37099篇
  2001年   59768篇
  2000年   61350篇
  1999年   52555篇
  1998年   15465篇
  1997年   14034篇
  1996年   14033篇
  1995年   13271篇
  1994年   12512篇
  1993年   11332篇
  1992年   41499篇
  1991年   40829篇
  1990年   40287篇
  1989年   39066篇
  1988年   36380篇
  1987年   35614篇
  1986年   33918篇
  1985年   32306篇
  1984年   24029篇
  1983年   20885篇
  1982年   12418篇
  1979年   22673篇
  1978年   15895篇
  1977年   13743篇
  1976年   12982篇
  1975年   14211篇
  1974年   16697篇
  1973年   16092篇
  1972年   15333篇
  1971年   14237篇
  1970年   13228篇
  1969年   12736篇
  1968年   11981篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
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   
53.
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   
54.
55.
56.
57.
58.
59.
Delayed contrast enhancement after injection of a gadolinium-chelate (Gd-chelate) is a reference imaging method to detect myocardial tissue changes. Its localization within the thickness of the myocardial wall allows differentiating various pathological processes such as myocardial infarction (MI), inflammatory myocarditis, and cardiomyopathies. The aim of the study was first to characterize benign myocarditis using quantitative delayed-enhancement imaging and then to investigate whether the measure of the extracellular volume fraction (ECV) can be used to discriminate between MI and myocarditis.In 6 patients with acute benign myocarditis (32.2 ± 13.8 year-old, subepicardial late gadolinium enhancement [LGE]) and 18 patients with MI (52.3 ± 10.9 year-old, subendocardial/transmural LGE), myocardial T1 was determined using the Modified Look-Locker Imaging (MOLLI) sequence at 3 Tesla before and after Gd-chelate injection. T1 values were compared in LGE and normal regions of the myocardium. The myocardial T1 values were normalized to the T1 of blood, and the ECV was calculated from T1 values of myocardium and blood pre- and post-Gd injection.In both myocarditis and MI, the T1 was lower in LGE regions than in normal regions of the left ventricle. T1 of LGE areas was significantly higher in myocarditis than in MI (446.8 ± 45.8 vs 360.5 ± 66.9 ms, P = 0.003) and ECV was lower in myocarditis than in MI (34.5 ± 3.3 vs 53.8 ± 13.0 %, P = 0.004).Both inflammatory process and chronic fibrosis induce LGE (subepicardial in myocarditis and subendocardial in MI). The present study demonstrates that the determination of T1 and ECV is able to differentiate the 2 histological patterns.Further investigation will indicate whether the severity of ECV changes might help refine the predictive risk of LGE in myocarditis.  相似文献   
60.
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