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   2384630篇
  免费   199351篇
  国内免费   4225篇
耳鼻咽喉   34426篇
儿科学   73195篇
妇产科学   63362篇
基础医学   336623篇
口腔科学   67880篇
临床医学   217342篇
内科学   470411篇
皮肤病学   48030篇
神经病学   201764篇
特种医学   96432篇
外国民族医学   886篇
外科学   362392篇
综合类   56517篇
现状与发展   1篇
一般理论   990篇
预防医学   192139篇
眼科学   55730篇
药学   178551篇
  4篇
中国医学   4387篇
肿瘤学   127144篇
  2018年   24474篇
  2016年   20756篇
  2015年   23495篇
  2014年   33841篇
  2013年   51306篇
  2012年   69470篇
  2011年   72998篇
  2010年   42882篇
  2009年   41216篇
  2008年   69392篇
  2007年   73832篇
  2006年   74645篇
  2005年   72653篇
  2004年   70001篇
  2003年   67603篇
  2002年   66807篇
  2001年   112828篇
  2000年   116920篇
  1999年   98666篇
  1998年   28022篇
  1997年   25689篇
  1996年   25588篇
  1995年   24741篇
  1994年   23282篇
  1993年   21666篇
  1992年   79666篇
  1991年   76646篇
  1990年   73820篇
  1989年   71070篇
  1988年   66088篇
  1987年   65020篇
  1986年   61569篇
  1985年   58602篇
  1984年   44411篇
  1983年   37818篇
  1982年   23010篇
  1981年   20445篇
  1980年   19169篇
  1979年   41481篇
  1978年   29117篇
  1977年   24469篇
  1976年   22915篇
  1975年   24071篇
  1974年   29768篇
  1973年   28157篇
  1972年   26354篇
  1971年   24239篇
  1970年   22849篇
  1969年   21209篇
  1968年   19239篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
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   
102.
103.
Objective: Report efficacy findings from three clinical trials (one phase 2 and two phase 3 [OPUS-1, OPUS-2]) of lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease (DED).

Research design and methods: Three 84-day, randomized, double-masked, placebo-controlled trials. Adults (≥18 years) with DED were randomized (1:1) to lifitegrast 5.0% or matching placebo. Changes from baseline to day 84 in signs and symptoms of DED were analyzed.

Main outcome measures: Phase 2, pre-specified endpoint: inferior corneal staining score (ICSS; 0–4); OPUS-1, coprimary endpoints: ICSS and visual-related function subscale (0–4 scale); OPUS-2, coprimary endpoints: ICSS and eye dryness score (EDS, VAS; 0–100).

Results: Fifty-eight participants were randomized to lifitegrast 5.0% and 58 to placebo in the phase 2 trial; 293 to lifitegrast and 295 to placebo in OPUS-1; 358 to lifitegrast and 360 to placebo in OPUS-2. In participants with mild-to-moderate baseline DED symptomatology, lifitegrast improved ICSS versus placebo in the phase 2 study (treatment effect, 0.35; 95% CI, 0.05–0.65; p?=?0.0209) and OPUS-1 (effect, 0.24; 95% CI, 0.10–0.38; p?=?0.0007). Among more symptomatic participants (baseline EDS ≥40, recent artificial tear use), lifitegrast improved EDS versus placebo in a post hoc analysis of OPUS-1 (effect, 13.34; 95% CI, 2.35–24.33; nominal p?=?0.0178) and in OPUS-2 (effect, 12.61; 95% CI, 8.51–16.70; p?<?0.0001).

Limitations: Trials were conducted over 12 weeks; efficacy beyond this period was not assessed.

Conclusions: Across three trials, lifitegrast improved ICSS in participants with mild-to-moderate baseline symptomatology in two studies, and EDS in participants with moderate-to-severe baseline symptomatology in two studies. Based on the overall findings from these trials, lifitegrast shows promise as a new treatment option for signs and symptoms of DED.  相似文献   
104.
105.
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   
106.
107.
108.
109.
110.
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   
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