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   378698篇
  免费   24805篇
  国内免费   2807篇
耳鼻咽喉   5183篇
儿科学   8207篇
妇产科学   10076篇
基础医学   53098篇
口腔科学   11807篇
临床医学   30114篇
内科学   78466篇
皮肤病学   8548篇
神经病学   27228篇
特种医学   13916篇
外国民族医学   82篇
外科学   60600篇
综合类   9955篇
现状与发展   1篇
一般理论   64篇
预防医学   17432篇
眼科学   9437篇
药学   31000篇
  1篇
中国医学   2192篇
肿瘤学   28903篇
  2021年   2611篇
  2019年   2728篇
  2018年   4520篇
  2017年   3437篇
  2016年   3521篇
  2015年   4020篇
  2014年   5697篇
  2013年   7381篇
  2012年   10030篇
  2011年   10220篇
  2010年   6195篇
  2009年   5846篇
  2008年   9462篇
  2007年   10306篇
  2006年   10230篇
  2005年   9298篇
  2004年   8814篇
  2003年   8533篇
  2002年   8204篇
  2001年   28270篇
  2000年   28790篇
  1999年   23668篇
  1998年   5162篇
  1997年   4249篇
  1996年   3831篇
  1995年   3478篇
  1994年   3103篇
  1993年   2843篇
  1992年   16049篇
  1991年   14811篇
  1990年   14154篇
  1989年   13962篇
  1988年   12584篇
  1987年   12062篇
  1986年   11102篇
  1985年   10322篇
  1984年   6911篇
  1983年   5599篇
  1982年   2718篇
  1979年   5478篇
  1978年   3348篇
  1977年   2972篇
  1975年   2641篇
  1974年   3064篇
  1973年   2865篇
  1972年   2828篇
  1971年   2774篇
  1970年   2511篇
  1969年   2543篇
  1968年   2250篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Nevo  N.  Goldstein  A. L.  Staierman  M.  Eran  N.  Carmeli  I.  Rayman  S.  mnouskin  Y. 《Hernia》2022,26(6):1491-1499
Hernia - The minimally invasive surgical repair of combined inguinal and ventral hernias often requires shifting from one approach or plane to another. The traditional enhanced-view totally...  相似文献   
13.
14.
15.
16.
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis.  相似文献   
17.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
18.
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   
19.
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