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   2387361篇
  免费   199518篇
  国内免费   4272篇
耳鼻咽喉   34471篇
儿科学   73287篇
妇产科学   63273篇
基础医学   336693篇
口腔科学   67862篇
临床医学   217160篇
内科学   471754篇
皮肤病学   48204篇
神经病学   202338篇
特种医学   96440篇
外国民族医学   886篇
外科学   362992篇
综合类   56587篇
现状与发展   1篇
一般理论   1008篇
预防医学   191971篇
眼科学   55887篇
药学   178564篇
  4篇
中国医学   4393篇
肿瘤学   127376篇
  2018年   24538篇
  2016年   20817篇
  2015年   23617篇
  2014年   33967篇
  2013年   51530篇
  2012年   69732篇
  2011年   73253篇
  2010年   43063篇
  2009年   41383篇
  2008年   69663篇
  2007年   74068篇
  2006年   74993篇
  2005年   73004篇
  2004年   70288篇
  2003年   67922篇
  2002年   67091篇
  2001年   112652篇
  2000年   116703篇
  1999年   98536篇
  1998年   28057篇
  1997年   25691篇
  1996年   25618篇
  1995年   24759篇
  1994年   23294篇
  1993年   21667篇
  1992年   79542篇
  1991年   76510篇
  1990年   73711篇
  1989年   70944篇
  1988年   65971篇
  1987年   64900篇
  1986年   61456篇
  1985年   58514篇
  1984年   44358篇
  1983年   37808篇
  1982年   23042篇
  1981年   20485篇
  1980年   19191篇
  1979年   41423篇
  1978年   29093篇
  1977年   24441篇
  1976年   22923篇
  1975年   24044篇
  1974年   29722篇
  1973年   28118篇
  1972年   26299篇
  1971年   24205篇
  1970年   22789篇
  1969年   21130篇
  1968年   19188篇
排序方式: 共有10000条查询结果,搜索用时 687 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