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   4074230篇
  免费   331806篇
  国内免费   14988篇
耳鼻咽喉   56757篇
儿科学   131220篇
妇产科学   106813篇
基础医学   625561篇
口腔科学   111459篇
临床医学   379545篇
内科学   731856篇
皮肤病学   106171篇
神经病学   344371篇
特种医学   159063篇
外国民族医学   575篇
外科学   622761篇
综合类   118696篇
现状与发展   92篇
一般理论   2600篇
预防医学   344346篇
眼科学   94606篇
药学   278263篇
  28篇
中国医学   10695篇
肿瘤学   195546篇
  2021年   56528篇
  2020年   37749篇
  2019年   59076篇
  2018年   75975篇
  2017年   58906篇
  2016年   64906篇
  2015年   78309篇
  2014年   115239篇
  2013年   180577篇
  2012年   112712篇
  2011年   116566篇
  2010年   126467篇
  2009年   130277篇
  2008年   103043篇
  2007年   108200篇
  2006年   117794篇
  2005年   112309篇
  2004年   113341篇
  2003年   103437篇
  2002年   92921篇
  2001年   135832篇
  2000年   129495篇
  1999年   122921篇
  1998年   69776篇
  1997年   66509篇
  1996年   64338篇
  1995年   59728篇
  1994年   53770篇
  1993年   49815篇
  1992年   89514篇
  1991年   86502篇
  1990年   83006篇
  1989年   81337篇
  1988年   75050篇
  1987年   74069篇
  1986年   70305篇
  1985年   69086篇
  1984年   59892篇
  1983年   53792篇
  1982年   45864篇
  1981年   42945篇
  1980年   40351篇
  1979年   51984篇
  1978年   43771篇
  1977年   38909篇
  1976年   36034篇
  1975年   35620篇
  1974年   39000篇
  1973年   37835篇
  1972年   35529篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
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   
15.
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   
16.
17.
18.
19.

Background

Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.

Methods

PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.

Results

Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.

Conclusions

MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.
  相似文献   
20.
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