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   195942篇
  免费   2386篇
  国内免费   104篇
耳鼻咽喉   1307篇
儿科学   6936篇
妇产科学   3234篇
基础医学   19541篇
口腔科学   2239篇
临床医学   14283篇
内科学   34996篇
皮肤病学   1241篇
神经病学   18973篇
特种医学   10190篇
外科学   31860篇
综合类   2401篇
一般理论   9篇
预防医学   19062篇
眼科学   3123篇
药学   10588篇
中国医学   679篇
肿瘤学   17770篇
  2023年   176篇
  2022年   238篇
  2021年   681篇
  2020年   461篇
  2019年   586篇
  2018年   22480篇
  2017年   17819篇
  2016年   20093篇
  2015年   1695篇
  2014年   1773篇
  2013年   1940篇
  2012年   8804篇
  2011年   22622篇
  2010年   19815篇
  2009年   12410篇
  2008年   20920篇
  2007年   23175篇
  2006年   2022篇
  2005年   3502篇
  2004年   4558篇
  2003年   5412篇
  2002年   3398篇
  2001年   437篇
  2000年   516篇
  1999年   332篇
  1998年   367篇
  1997年   337篇
  1996年   175篇
  1995年   156篇
  1994年   138篇
  1993年   104篇
  1992年   77篇
  1991年   103篇
  1990年   141篇
  1989年   94篇
  1988年   74篇
  1987年   51篇
  1986年   27篇
  1985年   35篇
  1984年   29篇
  1983年   26篇
  1982年   39篇
  1980年   49篇
  1974年   26篇
  1970年   24篇
  1938年   60篇
  1937年   27篇
  1934年   31篇
  1932年   57篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Gastroesophageal reflux is the most common benign disorder of the esophagus and laparoscopic Nissen fundoplication has become the standard surgical treatment for its treatment. In our area, where the use of bougie calibration is debatable, postoperative dysphagia is encountered often after this surgery although it is usually not permanent. The aim of this study was to investigate the effect of using a soft silicone tube 39 F in diameter for esophageal calibration during laparoscopic Nissen fundoplication on the incidence of postoperative dysphagia. We divided cases scheduled to undergo laparoscopic Nissen fundoplication between January 2009 and November 2010 into two groups, each consisting 25 patients. Esophageal calibration with a 39 F silicone orogastric tube was used for the first group while there was no operative calibration in the second group. The surgical duration was recorded; the presence and severity of the postoperative dysphagia was calculated by using a dysphagia severity scoring system during the 1-year postoperative follow-up. The dysphagia severity scores were significantly lower in group 1 than group 2 on the postoperative second day and at the end of the first week and first month. We did not find a significant difference at the end of the 6-month and first year. There was also no significant difference regarding surgery duration. The use of a soft orogastric tube 39 F in diameter for esophagus calibration during laparoscopic Nissen fundoplication has significantly decreased the incidence of postoperative transient dysphagia without affecting the duration of surgery. Although dysphagia gradually resolves in the majority of patients, a safe and easy calibration method for its prevention is worth developing, and we believe that the use of our method in larger series could be beneficial.  相似文献   
23.
24.
25.
During skeletal development the two ossification centers of the odontoid process are separated from the corpus of the axis by a subdental synchondrosis. This synchondrosis is thought to close and disappear spontaneously in adolescence although this has never been studied in detail. The basis of the dens is of clinical relevance as type II dens fractures are located here. To characterize the morphological architecture of the axis with particular attention to the subdental synchondrosis, the complete axis was harvested from thirty age-matched and gender-matched patients of the three different age groups at autopsy. The subdental synchondrosis and the bone structure of the dens, the basis of the dens and the body of C2 were analyzed by radiography, histology and quantitative histomorphometry. At the macroscopic level the persistency of the subdental synchondrosis in the adult cervical spine was detected in 87% (26 of 30) of the specimens. Histomorphometry revealed a residual disc blastema with an average size of 25.8% of the sagittal depth of the basis of the dens at this level. Bony integration of the synchondrosis was poor throughout all ages. Histologically a cartilaginous matrix composition of the subdental synchondrosis persisted throughout all groups. The trabecular microarchitecture demonstrated a significant reduction of bone volume and trabecular number as well as an increased trabecular separation within the basis of the dens as compared to the corpus or the dens of C2. This histomorphometric data regarding a poor integration of the synchondrosis into the trabecular network and the reduced bone mass within the basis of the dens might offer a previously underestimated explanation for the occurrence of type II dens fractures and their association with pseudoarthrosis, respectively.Matthias Gebauer and Christian Lohse contributed equally to this study and therefore share first authorship.  相似文献   
26.
27.
28.
29.
30.
INTRODUCTION H pylori infection is an established risk factor for development of gastric cancer[1,2]. According to the model of carcinogenesis of the intestinal type adenocarcinoma proposed by Correa, the multi-step development starts from the condition o…  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