首页 | 官方网站   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   3317982篇
  免费   269394篇
  国内免费   13503篇
医药卫生   3600879篇
  2021年   55051篇
  2020年   35081篇
  2019年   57956篇
  2018年   70878篇
  2017年   54056篇
  2016年   59758篇
  2015年   74008篇
  2014年   108240篇
  2013年   173395篇
  2012年   88461篇
  2011年   87673篇
  2010年   115702篇
  2009年   120443篇
  2008年   74541篇
  2007年   77048篇
  2006年   88110篇
  2005年   83136篇
  2004年   84942篇
  2003年   75969篇
  2002年   65694篇
  2001年   107256篇
  2000年   100093篇
  1999年   98970篇
  1998年   65044篇
  1997年   62853篇
  1996年   60619篇
  1995年   56176篇
  1994年   50070篇
  1993年   46831篇
  1992年   68154篇
  1991年   64465篇
  1990年   61554篇
  1989年   60669篇
  1988年   55657篇
  1987年   54116篇
  1986年   51306篇
  1985年   51044篇
  1984年   46734篇
  1983年   42752篇
  1982年   40804篇
  1981年   38400篇
  1980年   36336篇
  1979年   37754篇
  1978年   33423篇
  1977年   31389篇
  1976年   28185篇
  1975年   27076篇
  1974年   27258篇
  1973年   26246篇
  1972年   24633篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
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   
72.
73.
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.
80.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.  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-23

京公网安备 11010802026262号