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   3226983篇
  免费   247850篇
  国内免费   5618篇
耳鼻咽喉   47231篇
儿科学   102494篇
妇产科学   89428篇
基础医学   459335篇
口腔科学   92871篇
临床医学   289322篇
内科学   626220篇
皮肤病学   66668篇
神经病学   265261篇
特种医学   128156篇
外国民族医学   1170篇
外科学   489817篇
综合类   74131篇
现状与发展   2篇
一般理论   1195篇
预防医学   255018篇
眼科学   75927篇
药学   242872篇
  5篇
中国医学   6007篇
肿瘤学   167321篇
  2018年   31991篇
  2016年   27204篇
  2015年   30914篇
  2014年   44083篇
  2013年   67446篇
  2012年   91323篇
  2011年   96798篇
  2010年   56964篇
  2009年   54332篇
  2008年   92258篇
  2007年   98978篇
  2006年   100123篇
  2005年   97756篇
  2004年   94255篇
  2003年   90937篇
  2002年   89982篇
  2001年   146227篇
  2000年   151106篇
  1999年   128027篇
  1998年   37277篇
  1997年   33582篇
  1996年   33518篇
  1995年   32282篇
  1994年   30364篇
  1993年   28242篇
  1992年   103588篇
  1991年   100793篇
  1990年   98092篇
  1989年   94787篇
  1988年   88087篇
  1987年   86655篇
  1986年   82336篇
  1985年   78839篇
  1984年   59600篇
  1983年   51046篇
  1982年   30953篇
  1981年   27528篇
  1980年   25802篇
  1979年   56260篇
  1978年   39772篇
  1977年   33684篇
  1976年   31854篇
  1975年   34046篇
  1974年   41422篇
  1973年   39473篇
  1972年   37308篇
  1971年   34548篇
  1970年   32440篇
  1969年   30448篇
  1968年   28187篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
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   
92.
93.
94.
95.
96.
97.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
98.
99.
100.
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   
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