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   39773篇
  免费   2830篇
  国内免费   418篇
耳鼻咽喉   602篇
儿科学   645篇
妇产科学   748篇
基础医学   6067篇
口腔科学   883篇
临床医学   3515篇
内科学   7644篇
皮肤病学   1108篇
神经病学   2861篇
特种医学   2633篇
外科学   5720篇
综合类   332篇
一般理论   12篇
预防医学   1633篇
眼科学   1053篇
药学   3576篇
  1篇
中国医学   486篇
肿瘤学   3502篇
  2023年   280篇
  2022年   808篇
  2021年   1287篇
  2020年   701篇
  2019年   1067篇
  2018年   1165篇
  2017年   1004篇
  2016年   1294篇
  2015年   1870篇
  2014年   2180篇
  2013年   2472篇
  2012年   3473篇
  2011年   3351篇
  2010年   2083篇
  2009年   1790篇
  2008年   2382篇
  2007年   2220篇
  2006年   1999篇
  2005年   1933篇
  2004年   1619篇
  2003年   1405篇
  2002年   1250篇
  2001年   816篇
  2000年   807篇
  1999年   625篇
  1998年   254篇
  1997年   226篇
  1996年   200篇
  1995年   163篇
  1994年   140篇
  1993年   113篇
  1992年   258篇
  1991年   198篇
  1990年   184篇
  1989年   174篇
  1988年   149篇
  1987年   110篇
  1986年   101篇
  1985年   74篇
  1984年   82篇
  1983年   53篇
  1982年   56篇
  1981年   45篇
  1980年   44篇
  1979年   56篇
  1978年   44篇
  1977年   46篇
  1976年   38篇
  1972年   44篇
  1971年   44篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
1.
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations.  相似文献   
2.
3.
Moderate sedatives have been increasingly used to improve patient comfort during flexible bronchoscopy (FB). However, routine use of moderate sedation during FB is controversial because its efficacy and safety are not well established.This study aims to evaluate the efficacy and safety of moderate sedation during FB.A search was made of Medline, EMBASE, and the Cochrane Library to May 2014.Randomized controlled trials (RCTs) and quasi-RCTs were included.The main analysis was designed to examine the efficacy of moderate sedation during FB in sedation than no-sedation.The willingness to repeat FB was significantly more in sedation than no-sedation (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.11–4.73; P = 0.02; I2 = 22.5). The duration of FB was shorter in sedation group than no-sedation group (standardized mean difference [SMD] −0.21; 95% CI −0.38 to −0.03; P = 0.02; I2 = 78.3%). Event of hypoxia was not significantly different between sedation and no-sedation groups (OR 0.86; 95% CI 0.42–1.73; P = 0.67; I2 = 0%). The SpO2 during procedure was not different between sedation and no-sedation groups (SMD −0.14; 95% CI −0.37 to 0.08; P = 0.21; I2 = 49.9%). However, in subgroup analysis without supplemental oxygen, the SpO2 was significantly lower in sedation than no-sedation group (SMD −0.45; 95% CI −0.78 to −0.11; P = 0.01; I2 = 0.0%).According to this meta-analysis, moderate sedation in FB would be useful in patients who will require repeated bronchoscopies as well as safe in respiratory depression. To our knowledge, although the various sedative drugs are already used in the real field, this analysis was the first attempt to quantify objective results. We anticipate more definite and studies designed to elucidate standardized outcomes for moderate sedation in FB.  相似文献   
4.
5.
6.
7.
8.
9.
10.
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