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   4134篇
  免费   221篇
  国内免费   29篇
耳鼻咽喉   31篇
儿科学   37篇
妇产科学   98篇
基础医学   663篇
口腔科学   127篇
临床医学   294篇
内科学   790篇
皮肤病学   81篇
神经病学   305篇
特种医学   237篇
外科学   543篇
综合类   17篇
预防医学   172篇
眼科学   109篇
药学   460篇
中国医学   46篇
肿瘤学   374篇
  2023年   36篇
  2022年   57篇
  2021年   123篇
  2020年   59篇
  2019年   77篇
  2018年   103篇
  2017年   75篇
  2016年   139篇
  2015年   189篇
  2014年   206篇
  2013年   247篇
  2012年   346篇
  2011年   346篇
  2010年   209篇
  2009年   175篇
  2008年   258篇
  2007年   263篇
  2006年   205篇
  2005年   191篇
  2004年   164篇
  2003年   149篇
  2002年   118篇
  2001年   122篇
  2000年   120篇
  1999年   71篇
  1998年   25篇
  1997年   25篇
  1996年   19篇
  1995年   7篇
  1994年   9篇
  1993年   11篇
  1992年   22篇
  1991年   29篇
  1990年   15篇
  1989年   20篇
  1988年   10篇
  1987年   14篇
  1986年   14篇
  1985年   13篇
  1984年   6篇
  1983年   6篇
  1982年   9篇
  1981年   7篇
  1979年   5篇
  1978年   6篇
  1977年   7篇
  1975年   5篇
  1972年   7篇
  1967年   7篇
  1921年   4篇
排序方式: 共有4384条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
65.
66.
67.
The accurate diagnosis of glioma subtypes is critical for appropriate treatment, but conventional histopathologic diagnosis often exhibits significant intra‐observer variability and sampling error. The aim of this study was to investigate whether histogram analysis using an automatically segmented region of interest (ROI), excluding cystic or necrotic portions, could improve the differentiation between low‐grade and high‐grade gliomas. Thirty‐two patients (nine low‐grade and 23 high‐grade gliomas) were included in this retrospective investigation. The outer boundaries of the entire tumors were manually drawn in each section of the contrast‐enhanced T1‐weighted MR images. We excluded cystic or necrotic portions from the entire tumor volume. The histogram analyses were performed within the ROI on normalized apparent diffusion coefficient (ADC) maps. To evaluate the contribution of the proposed method to glioma grading, we compared the area under the receiver operating characteristic (ROC) curves. We found that an ROI excluding cystic or necrotic portions was more useful for glioma grading than was an entire tumor ROI. In the case of the fifth percentile values of the normalized ADC histogram, the area under the ROC curve for the tumor ROIs excluding cystic or necrotic portions was significantly higher than that for the entire tumor ROIs (p < 0.005). The automatic segmentation of a cystic or necrotic area probably improves the ability to differentiate between high‐ and low‐grade gliomas on an ADC map. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
68.
The aim of this paper is to provide an account of the history, current status and vision of the Korean Institute on Alcohol Problems (KIAP). In the context of increasing alcohol consumption, rising second‐hand effects and industry‐friendly government policy, the Korean College Alcohol Study (KCAS) was established in the Republic of Korea in 1999, and changed its name to the Korean Institute on Alcohol Problems (KIAP) in 2005. KIAP's mission is to decrease alcohol consumption and its related harms by promoting research, advocating policy, developing intervention programmes and preparing media communications. Since 1999, KIAP has published scientific papers and books in alcohol research and used the internet and other media for dissemination of specialized information to the general population. In the last decade, KIAP has trained front‐line alcohol researchers, and advanced domestic and international networks to promote evidence‐based alcohol control policy in Korea. The light of hope shines brightly as KIAP grows and establishes critical linkages to move forward in its mission.  相似文献   
69.
BACKGROUND/AIMS: Antibiotic resistance and poor compliance are the main causes of Helicobacter pylori (H. pylori) eradication failure. This study evaluated the eradication rate, tolerability, and compliance of levofloxacin- azithromycin combined triple therapy for H. pylori eradication. METHODS: 1) First-line eradication: A total of 78 H. pylori-positive patients were enrolled. Seventeen military men in Armed Forces Capital Hospital were treated with 7 days of levofloxacin-azithromycin combined triple therapy (omeprazole 20 mg bid, levofloxacin 500 mg od, and azithromycin 500 mg od), and 61 patients in Kangbuk Samsung Hospital were treated with standard PPI-based triple therapy (omeprazole 20 mg bid, amoxicillin 1.0 g bid, and clarithromycin 500 mg bid) for 7 days. 2) Second-line eradication: A consecutive series of 59 patients who failed H. pylori eradication with standard PPI-based triple therapy in Kangbuk Samsung Hospital were randomized to two groups. Thirty patients were retreated with 7 days of bismuth-based quadruple therapy (omeprazole 20 mg bid, bismuth 120 mg qid, metronidazole 500 mg tid, and tetracycline 500 mg qid), and remaining 29 patients were retreated with levofloxacin-azithromycin combined triple therapy. Patient's compliance and tolerability were evaluated at the end of treatment. The status of H. pylori infection was assessed 8 weeks later then. The successful eradication of H. pylori was defined as negative results from histology and CLO test, or 13C-urea breath test. RESULTS: First-line eradication rate of levofloxacin-azithromycin triple therapy was lower than that of standard PPI-based triple therapy, but there was no statistically significant difference (70.6% vs. 80.3%, p=0.390). Second-line eradication rate of levofloxacin-azithromycin combined triple therapy was significantly lower than that of bismuth-based quadruple therapy (ITT/PP 65.5%/73.1% vs. 90%/90%, p<0.0001). The compliances of all patients were more than 85%. Two of patients with levofloxacin-azithromycin combined triple therapy complained self-limiting side effects (mild dizziness; mild insomnia with general weakness). CONCLUSIONS: Levofloxacin-azithromycin combined triple therapy should not be recommended as the first-line or second-line H. pylori eradication regimen in Korea.  相似文献   
70.
Seven patients underwent attempted low pressure balloon dilation of stenotic conduits or homografts from right ventricle to pulmonary artery (n=5), in the aortic valve position (n=1), or from right atrium to left pulmonary artery (n=1). In the right ventricle to pulmonary artery group, mean gradient reduction was only 17%. At follow-up, two patients underwent surgical conduit replacement, one had a stent implanted at cardiac catheterization, the other two are awaiting surgical intervention. The patient with a homograft in the aortic valve position had a good initial result but restenosed within 1 year and underwent a pulmonary autograft operation. The patient with the Fontan homograft stenosis had transient obstruction relief but subsequently required stent implantation. Low-pressure balloon dilation of conduits or homografts is only partially and transiently successful. Whether stent implantation will offer better long-term results remains to be determined.  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