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   3222189篇
  免费   240569篇
  国内免费   8192篇
耳鼻咽喉   43751篇
儿科学   104550篇
妇产科学   87337篇
基础医学   462639篇
口腔科学   89562篇
临床医学   293057篇
内科学   630435篇
皮肤病学   73516篇
神经病学   257870篇
特种医学   124190篇
外国民族医学   743篇
外科学   488908篇
综合类   70686篇
现状与发展   14篇
一般理论   1169篇
预防医学   257671篇
眼科学   73541篇
药学   235768篇
  15篇
中国医学   6023篇
肿瘤学   169505篇
  2018年   35210篇
  2017年   26839篇
  2016年   30840篇
  2015年   34706篇
  2014年   48837篇
  2013年   73736篇
  2012年   97594篇
  2011年   104294篇
  2010年   63077篇
  2009年   60187篇
  2008年   97524篇
  2007年   104049篇
  2006年   105383篇
  2005年   102206篇
  2004年   97563篇
  2003年   94349篇
  2002年   91042篇
  2001年   146491篇
  2000年   150359篇
  1999年   126759篇
  1998年   38057篇
  1997年   33534篇
  1996年   34260篇
  1995年   33261篇
  1994年   30751篇
  1993年   28942篇
  1992年   100991篇
  1991年   98552篇
  1990年   95867篇
  1989年   92059篇
  1988年   84942篇
  1987年   83396篇
  1986年   78521篇
  1985年   75514篇
  1984年   56894篇
  1983年   48331篇
  1982年   29352篇
  1981年   26429篇
  1979年   52204篇
  1978年   37575篇
  1977年   31360篇
  1976年   29704篇
  1975年   31632篇
  1974年   37757篇
  1973年   35914篇
  1972年   33774篇
  1971年   31657篇
  1970年   29013篇
  1969年   27627篇
  1968年   25460篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
65.
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction.  相似文献   
66.
67.
68.
69.
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   
70.
Guidelines and consensus on the management of patients with acne aim to give evidence-based, expert-group recommendations. This review compares current guidelines and consensus articles to provide a compilation of recommendations on the treatment of acne with oral isotretinoin. Ten common, relevant, clinical questions are addressed, based on published recommendations, including the indications of isotretinoin, the proposed daily dose, the cumulative isotretinoin dose and the laboratory monitoring needed. Recommendations on special considerations are also addressed, including the timing of procedures and the question of an association of depression or inflammatory bowel disease with isotretinoin. A major limitation is the use of different classification systems for acne across guidelines. The recommended daily dose ranges from 0.3 to 0.5 mg/kg in the European guidelines to up to 1 mg/kg in the US guidelines. A specific duration of treatment of at least 6 months is only recommended in the European guidelines. All guidelines report the need of strict pregnancy prevention measures. The European, French and US guidelines recommend to monitor for symptoms of depression. Important clinical questions that are inconsistently addressed in guidelines include the age indication, the recommendation for a cumulative dose, the timing of procedures, the association of isotretinoin with IBD, the recommendation for preventing acne flares and for appropriate laboratory monitoring. These topics should be clearly included in the recommendations of guidelines as they are often raised in everyday clinical practice.  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