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   4801篇
  免费   313篇
  国内免费   91篇
耳鼻咽喉   259篇
儿科学   154篇
妇产科学   17篇
基础医学   149篇
口腔科学   77篇
临床医学   1052篇
内科学   314篇
皮肤病学   10篇
神经病学   31篇
特种医学   133篇
外科学   1303篇
综合类   938篇
预防医学   153篇
眼科学   134篇
药学   334篇
  7篇
中国医学   51篇
肿瘤学   89篇
  2024年   5篇
  2023年   93篇
  2022年   133篇
  2021年   158篇
  2020年   161篇
  2019年   124篇
  2018年   171篇
  2017年   168篇
  2016年   142篇
  2015年   180篇
  2014年   354篇
  2013年   326篇
  2012年   323篇
  2011年   338篇
  2010年   280篇
  2009年   235篇
  2008年   202篇
  2007年   224篇
  2006年   210篇
  2005年   170篇
  2004年   151篇
  2003年   120篇
  2002年   114篇
  2001年   83篇
  2000年   83篇
  1999年   71篇
  1998年   50篇
  1997年   63篇
  1996年   37篇
  1995年   55篇
  1994年   64篇
  1993年   33篇
  1992年   30篇
  1991年   32篇
  1990年   31篇
  1989年   26篇
  1988年   21篇
  1987年   21篇
  1986年   11篇
  1985年   16篇
  1984年   30篇
  1983年   12篇
  1982年   13篇
  1981年   11篇
  1980年   14篇
  1979年   3篇
  1978年   3篇
  1977年   5篇
  1975年   3篇
  1970年   1篇
排序方式: 共有5205条查询结果,搜索用时 502 毫秒
11.
本研究建立了大鼠气管上皮细胞体内-体外转化模型,大鼠气管内滴注苯并芘,三天后处死大鼠,消化气管上皮细胞,接种于无血清完全培养基。细胞形成集落后,换为选择培养基继续培养五周,统计转化率。结果显示,25mg/kg和50mg/kg的苯并芘可诱导大鼠气管上皮细胞转化及微核增加,用同样方法研究了煤焦沥青提取物,结果表明,剂量为8mg/kg和25mg/kg的煤焦沥青提取物能明显诱导大鼠气管上皮细胞转化。  相似文献   
12.
气管与主支气管肿瘤的影像诊断(附32例报告)   总被引:5,自引:1,他引:4  
作者对32例经病理证实的气管与主支气管良、恶性肿瘤的影像学表现进行分析,归纳为3型:腔内型、壁增厚型和腔内外型。后2种类型提示恶性,而无蒂的腔内型表现者不能鉴别良,恶性。作者还评价了常规体层、CT及MRI诊断气管与主支气管肿瘤的优、缺点,讨论了影像诊断的作用。  相似文献   
13.
14.
15.
BACKGROUND: Caecal intubation is a necessary step in the complete endoscopic evaluation of the colon. Studies have estimated that experienced colonoscopists may fail to reach the caecum in up to 10% of cases. AIMS: To evaluate the utility of the double balloon enteroscope used for complete examination of the colon in patients with incomplete standard colonoscopy. PATIENTS: Twenty consecutive patients with incomplete colonoscopies within the Veterans Affairs Palo Alto Health Care System. Mean age of 66 years (S.D.+/-12 years, range 46-84), 16 men. METHODS: Prospective single-centre case series on the caecal intubation rate using standard double balloon enteroscope technique in patients with previous incomplete conventional colonoscopy. RESULTS: Use of the standard double balloon enteroscope technique permitted complete colonoscopy to be achieved in 95% of the patients (19/20). Seven patients (35%) had significant pathology beyond the extent of the prior incomplete colonoscopy. We performed endoscopic mucosal resection, polypectomy or biopsy. The mean time to reach the caecum was 28 min (S.D.+/-20 min, range 6-90 min). The sedation was similar to conventional colonoscopy. No complications occurred. CONCLUSIONS: The double balloon enteroscope technology and technique can be used to complete examination of the colon in patients who were referred because of incomplete standard colonoscopy.  相似文献   
16.
Three patients are described in whom it was impossible to visualise the larynx at direct laryngoscopy. Tracheal intubation was successfully and rapidly achieved with the aid of continuous fluoroscopy.  相似文献   
17.
Background : The study aimed to assess the relative influence of anaesthesia and muscle relaxation on intubating conditions and the haemodynamic and catecholamine responses to tracheal intubation.
Methods : Sixty ASA 1 or 2 patients were randomly assigned to one of four groups (15 patients each) that differed in the depth of anaesthesia (thiopentone plus fentanyl 2.5 μg kg-1 or thiopentone alone) and the degree of vecuronium–induced neuromuscular block (100% or _>: 65%) at intubation. Muscle relaxation was measured at 0.1 Hz by means of mechanomyography. Heart rate (HR) and mean arterial blood pressure (MAP) were measured before and after induction of anaesthesia, and 1 min and 5 min following intubation, while adrenaline (A) and noradrenaline concentrations (NA) were determined from arterial blood samples.
Results : Intubating conditions were improved primarily by providing complete muscle relaxation at the adductor pollicis muscle (P<0.001) and to a lesser extent by adding fentanyl to thiopentone (P=0.04). The response of HR and MAP to tracheal intubation was attenuated mainly by fentanyl (P<0.001). Complete muscle relaxation further diminished the response of MAP to intubation (P=0.03). Changes in A and NA were dependent on the depth of anaesthesia only (P =>0.01).
Conclusion : The results of the study demonstrate that the sympathoadrenal response to intubation is attenuated by adding fentanyl (2.5 kg-1) to an induction regimen with thiopentone, whereas provision of complete muscle relaxation at the adductor pollicis muscle is necessary to attain smooth intubating conditions.  相似文献   
18.
Background: The use of muscle relaxants to facilitate intubation is associated with several side effects regardless of whether depolarizing or non-depolarizing drugs are used. In the present study we compared the intubating conditions, haemodynamic responses and changes in oxygen saturation following induction with alfentanil and propofol or alfentanil, thiopental and suxamethonium.
Methods: Eighty patients (ASA I or II) were in a double-blind manner assigned to receive either of the two induction methods. Intubating conditions were assessed on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing on intubation. Heart rate, systolic arterial pressure and oxygen saturation were monitored throughout the procedure.
Results: The use of alfentanil and propofol resulted in significantly lower scored intubation points. Systolic arterial pressure decreased and heart rate increased significantly in the alfentanil-thiopental-suxamethonium group as compared to the alfentanil-propofol group. There were no significant changes in oxygen saturation.
Conclusion: The results show that propofol and alfentanil in combination provides haemodynamic stability and unaltered oxygen saturation but less optimal intubating conditions.  相似文献   
19.
20.
162例气管插管患者的气道管理   总被引:16,自引:2,他引:14  
杨春娥 《护理学报》2004,11(1):20-21
笔者通过报道162例气管插管患者的气道管理,阐述痰痂形成的原因:(1)气道干燥,湿化不够。(2)吸痰管插入深度不够,吸痰不彻底。管理措施:(1)用金霉素眼膏润滑吸痰管,使之易于插入,保证吸痰管插入深度超过插管远端3-5cm。(2)预防气道干燥,注重湿化效果,重视吸痰环节。认为气囊不需定时放气,只需不定时调整气囊压力。  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