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   68922篇
  免费   5232篇
  国内免费   1803篇
耳鼻咽喉   905篇
儿科学   1301篇
妇产科学   2315篇
基础医学   9014篇
口腔科学   1257篇
临床医学   7244篇
内科学   12839篇
皮肤病学   1303篇
神经病学   4386篇
特种医学   2965篇
外国民族医学   6篇
外科学   9227篇
综合类   4210篇
现状与发展   7篇
一般理论   11篇
预防医学   3599篇
眼科学   1610篇
药学   5820篇
  20篇
中国医学   1776篇
肿瘤学   6142篇
  2023年   490篇
  2022年   1169篇
  2021年   2326篇
  2020年   1398篇
  2019年   1784篇
  2018年   2214篇
  2017年   1637篇
  2016年   1780篇
  2015年   2598篇
  2014年   3268篇
  2013年   3751篇
  2012年   5416篇
  2011年   5225篇
  2010年   3313篇
  2009年   2875篇
  2008年   3903篇
  2007年   3868篇
  2006年   3670篇
  2005年   3362篇
  2004年   3026篇
  2003年   2904篇
  2002年   2532篇
  2001年   1890篇
  2000年   1643篇
  1999年   1357篇
  1998年   582篇
  1997年   476篇
  1996年   438篇
  1995年   386篇
  1994年   361篇
  1993年   248篇
  1992年   720篇
  1991年   595篇
  1990年   538篇
  1989年   499篇
  1988年   431篇
  1987年   431篇
  1986年   362篇
  1985年   304篇
  1984年   230篇
  1983年   197篇
  1982年   118篇
  1981年   125篇
  1980年   103篇
  1979年   207篇
  1978年   164篇
  1977年   105篇
  1976年   111篇
  1975年   104篇
  1974年   103篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
11.
12.
13.
14.
15.
目的 检测微小核糖核酸(microribonucleicacids,miRNA)在老年性黄斑变性(age-related macular degeneration,AMD)患者中的表达,并探讨miRNA的表达量与AMD病程之间的关系。方法 选取2014年1月至2016年11月于同济大学附属第十人民医院眼科门诊就诊的AMD患者6例为试验组,并选取同期6名正常人为对照组,通过基因芯片技术检测两组血液中miRNA的表达量。扩大样本的病例对照研究中共纳入126例AMD患者和140名正常人,检测其血液样本中miRNA的表达,比较两组人群间miRNA的表达量差异。结果 通过基因芯片技术,在试验组与对照组间共检测出216个miRNA存在表达差异(均为P<0.05),与对照组相比,试验组中111个miRNA表达量上升,105个miRNA表达量下降,差异均有统计学意义(均为P<0.05)。扩大样本的病例对照研究结果表明,在AMD患者中,miR-27a-3p、miR-29b-3p、miR-195-5p的表达量显著上升,同时,湿性AMD患者血液中miR-27a-3p的表达量高于干性AMD患者,差异均有统计学意义(均为P<0.05)。结论 AMD患者外周血中miRNA表达量水平有明显变化,miR-27a-3p、miR-29b-3p、miR-195-5p可能成为AMD血清学诊断和预后的标志物。  相似文献   
16.

Background

Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.

Methods

We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A?]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.

Results

Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A? (17 versus 7; P?=?.0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A?. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.

Conclusions

In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits.  相似文献   
17.

Introduction

For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM2.5) levels on LC in Taiwan, in relation to contrasting PM2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).

Methods

We reviewed 371,084 patients with LC to assess smoking prevalence and correlations between the incidence of adenocarcinoma lung cancer (AdLC) and non-AdLC. Two subsets were selected to assess different AdLC stage trends and the effect of PM2.5 on survival of patients with AdLC.

Results

From 1995 to 2015, the proportion of male adult ever-smokers decreased from 59.4% to 29.9% whereas the female smoking rate remained low (3.2% to 5.3%). AdLC incidence in males and females increased from 9.06 to 23.25 and 7.05 to 24.22 per 100,000 population, respectively. Since 1993, atmospheric visibility in NT improved (from 7.6 to 11.5 km), but deteriorated in ST (from 16.3 to 4.2 km). The annual percent change in AdLC stages IB to IV was 0.3% since 2009 (95% confidence interval [CI]: -1.9%–2.6%) in NT, and 4.6% since 2007 (95% CI: 3.3%–5.8%) in ST; 53% patients with LC had never smoked. Five-year survival rates for never-smokers, those with EGFR wild-type genes, and female patients with AdLC were 12.6% in NT and 4.5% in ST (hazard ratio: 0.79, 95% CI: 0.70–0.90).

Conclusions

In Taiwan, greater than 50% of patients with LC had never smoked. PM2.5 level changes can affect AdLC incidence and patient survival.  相似文献   
18.
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