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   45942篇
  免费   3166篇
  国内免费   609篇
耳鼻咽喉   858篇
儿科学   743篇
妇产科学   983篇
基础医学   6891篇
口腔科学   799篇
临床医学   3803篇
内科学   9634篇
皮肤病学   1513篇
神经病学   3146篇
特种医学   2562篇
外科学   6462篇
综合类   592篇
一般理论   16篇
预防医学   2026篇
眼科学   1197篇
药学   4018篇
中国医学   546篇
肿瘤学   3928篇
  2023年   294篇
  2022年   885篇
  2021年   1468篇
  2020年   745篇
  2019年   1194篇
  2018年   1382篇
  2017年   964篇
  2016年   1384篇
  2015年   1862篇
  2014年   2231篇
  2013年   2549篇
  2012年   3767篇
  2011年   3773篇
  2010年   2256篇
  2009年   1907篇
  2008年   2743篇
  2007年   2543篇
  2006年   2324篇
  2005年   2193篇
  2004年   1826篇
  2003年   1756篇
  2002年   1585篇
  2001年   1011篇
  2000年   933篇
  1999年   832篇
  1998年   331篇
  1997年   284篇
  1996年   264篇
  1995年   211篇
  1994年   191篇
  1993年   125篇
  1992年   372篇
  1991年   293篇
  1990年   320篇
  1989年   305篇
  1988年   298篇
  1987年   241篇
  1986年   226篇
  1985年   215篇
  1984年   177篇
  1983年   163篇
  1982年   96篇
  1981年   90篇
  1980年   88篇
  1979年   155篇
  1978年   112篇
  1977年   89篇
  1975年   76篇
  1974年   74篇
  1973年   73篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
4.
5.
ABSTRACT

Purpose

Work-related eye injuries have been reported with a variety of epidemiologic and clinical characteristics. We aimed to identify epidemiologic characteristics of work-related eye injuries and risk factors associated with severe injury in a large metropolitan city.  相似文献   
6.
7.
8.
9.
Psoriasis is a chronic, inflammatory, immune‐mediated disease. Approximately 30% of patients have disease onset before age 18 years. Psoriasis in children and adolescents may be difficult to control, with subsequent poor quality of life and psychosocial consequences. We describe the case of a 12‐year‐old boy with severe, refractory, chronic plaque psoriasis for 6 years. Various therapeutic regimens including different topical corticosteroids, topical vitamin D analogs, phototherapy, photochemotherapy, systemic therapy with methotrexate, cyclosporin, and combination therapies showed only partial or transient responses with frequent relapses. Because anti‐interleukin‐12/23 agents have been successfully used in adults with psoriasis, ustekinumab was initiated and our patient showed a rapid, excellent, sustained response. No recurrence or flares have been observed after 33 months of follow‐up. This case illustrates that ustekinumab may be an effective and safe therapeutic option in adolescents with psoriasis.  相似文献   
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