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   1406篇
  免费   138篇
  国内免费   9篇
耳鼻咽喉   12篇
儿科学   72篇
妇产科学   15篇
基础医学   202篇
口腔科学   31篇
临床医学   137篇
内科学   338篇
皮肤病学   24篇
神经病学   26篇
特种医学   256篇
外科学   128篇
综合类   71篇
预防医学   84篇
眼科学   20篇
药学   46篇
中国医学   9篇
肿瘤学   82篇
  2021年   10篇
  2019年   15篇
  2018年   22篇
  2017年   20篇
  2016年   16篇
  2015年   28篇
  2014年   63篇
  2013年   80篇
  2012年   51篇
  2011年   58篇
  2010年   46篇
  2009年   65篇
  2008年   40篇
  2007年   67篇
  2006年   41篇
  2005年   34篇
  2004年   35篇
  2003年   23篇
  2002年   25篇
  2001年   17篇
  2000年   19篇
  1999年   18篇
  1998年   82篇
  1997年   56篇
  1996年   64篇
  1995年   46篇
  1994年   51篇
  1993年   46篇
  1992年   14篇
  1991年   10篇
  1990年   14篇
  1989年   43篇
  1988年   31篇
  1987年   28篇
  1986年   21篇
  1985年   14篇
  1984年   17篇
  1983年   16篇
  1982年   16篇
  1981年   21篇
  1980年   13篇
  1979年   12篇
  1978年   12篇
  1977年   21篇
  1976年   12篇
  1975年   18篇
  1974年   10篇
  1973年   16篇
  1972年   9篇
  1970年   9篇
排序方式: 共有1553条查询结果,搜索用时 31 毫秒
1.
2.
目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月~2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转,但于伤后5-10d出现恶化,CT复查有脑肿胀,经加强综合脱水等治疗后16例治愈,1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强,应加强观察、积极行CT复查,如能早期明确诊断,保守治疗多数效果良好。  相似文献   
3.
4.
Retrorenal colon: implications for percutaneous diskectomy   总被引:1,自引:0,他引:1  
Helms  CA; Munk  PL; Witt  WS; Davis  GW; Morris  J; Onik  G 《Radiology》1989,171(3):864-865
It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.  相似文献   
5.
6.
7.
8.
Seventeen consecutive patients were referred for management of empyema between April 1991 and March 1992. Fourteen patients defined as having an 'early' empyema were initially treated by videothoracoscopy. The other three patients, defined as having a 'late' empyema proceeded directly to thoracotomy. Videothoracoscopy was successful in 10 out of the 14 patients. The mean postoperative stay was 7.8 days. At a mean follow-up at 16.7 months, these patients were rendered apyrexial with full lung expansion and no residual pleural collection. The postoperative results were at least equivalent to other conventional forms of treatment without an undue level of complications. In this series, thoracoscopy was found to be successful when symptoms had been present up to 31 days before presentation at the first hospital, and the mean length of treatment before referral to Harefield was 47 days. It is now our policy to videothoracoscope all patients with empyema thoracis, regardless of the length of referral. It may circumvent the need for a thoracotomy, it does not add any increased risk of complications, and does not appreciably increase the length of hospital stay should thoracotomy ultimately be required.  相似文献   
9.
Colonization in the respiratory tracts of cystic fibrosis (CF) patients by mucoid Pseudomonas aeruginosa correlates with the progression of bronchial airway pathology. There is a direct correlation between the incidence of Pseudomonas colonization and age, clinical score, extent of pulmonary disease, severity of radiographic changes, and level of serum immunoglobulins. The central propensity to Pseudomonas colonization in patients with CF is not freely understood, but we discuss the acquisition and persistence of P aeruginosa in the CF airway. Elucidation of pathogenetic mechanisms of CF inflammatory airways disease is the first essential step to initiating novel therapies. It has been difficult to prove that the ability of P aeruginosa to adhere to the respiratory epithelium and provide selective advantage for this gram-negative bacillus over other potential pathogens for infection in the CF airway. However, flexible filaments (pili) extending from the Pseudomonas cell wall are thought to medicate epithelial cell adherence for nonmucoid P aeruginosa, and similarly, the gelatinous exopolysaccharide alginate produced by mucoid variants of P aeruginosa seems to be the adhesive to tracheal cells. Following the signal event of adherence, this bacterial pathogen competes successfully for iron cofactor and multiplies, releasing proteases with broad substrate specificities that dramatically alter the airway antiprotease screen, and the pathogen creates defects in local antibacterial defenses. Lung inflammation in CF is characterized by massive neutrophil infiltration. Although critical to host defense, neutrophils also cause progressive airway damage by release of bioactive lipids, oxygen metabolites, and granule enzymes such as hydrolases, myeloperoxidase (MPO), lysozyme, and neutral serine proteases. The necessarily circumscribed discussion that follows will focus narrowly on the host cell-derived factors (macrophages and neutrophils) proposed as important components in this pathogenetic scheme.  相似文献   
10.
采用间接ELISA检测23名肾移植受者血清巨细胞病毒(CMV)抗体,共检出18名(78%)活动性CMV感染,其中10名(44%)为原发性感染。结果证实CMV-IgE和-IgA具有较好的血清学诊断价值,优于CMV-IgM。  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