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   909005篇
  免费   64186篇
  国内免费   2429篇
耳鼻咽喉   12663篇
儿科学   28817篇
妇产科学   26376篇
基础医学   128268篇
口腔科学   24907篇
临床医学   75584篇
内科学   184901篇
皮肤病学   19546篇
神经病学   72037篇
特种医学   37131篇
外国民族医学   336篇
外科学   143854篇
综合类   19065篇
一般理论   248篇
预防医学   65141篇
眼科学   20257篇
药学   64725篇
中国医学   1956篇
肿瘤学   49808篇
  2018年   9370篇
  2017年   7386篇
  2016年   8033篇
  2015年   9216篇
  2014年   12960篇
  2013年   19902篇
  2012年   26632篇
  2011年   28220篇
  2010年   17161篇
  2009年   16243篇
  2008年   26779篇
  2007年   28339篇
  2006年   28459篇
  2005年   27998篇
  2004年   26713篇
  2003年   25824篇
  2002年   25377篇
  2001年   41563篇
  2000年   42768篇
  1999年   36433篇
  1998年   10029篇
  1997年   9193篇
  1996年   9123篇
  1995年   8476篇
  1994年   8109篇
  1993年   7609篇
  1992年   28248篇
  1991年   27024篇
  1990年   26454篇
  1989年   25372篇
  1988年   23590篇
  1987年   23205篇
  1986年   22284篇
  1985年   21185篇
  1984年   15840篇
  1983年   13522篇
  1982年   8100篇
  1979年   14613篇
  1978年   10233篇
  1977年   8646篇
  1976年   8165篇
  1975年   8973篇
  1974年   10710篇
  1973年   10202篇
  1972年   9672篇
  1971年   8926篇
  1970年   8594篇
  1969年   8031篇
  1968年   7693篇
  1967年   7097篇
排序方式: 共有10000条查询结果,搜索用时 859 毫秒
21.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  相似文献   
22.
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   
23.
Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (Pacnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.  相似文献   
24.
25.
26.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
27.
28.
29.
30.
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