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   8195篇
  免费   918篇
  国内免费   169篇
耳鼻咽喉   82篇
儿科学   319篇
妇产科学   189篇
基础医学   477篇
口腔科学   140篇
临床医学   1711篇
内科学   1774篇
皮肤病学   150篇
神经病学   488篇
特种医学   252篇
外科学   1886篇
综合类   52篇
一般理论   1篇
预防医学   692篇
眼科学   366篇
药学   305篇
中国医学   3篇
肿瘤学   395篇
  2023年   118篇
  2021年   95篇
  2020年   126篇
  2019年   98篇
  2018年   190篇
  2017年   218篇
  2016年   235篇
  2015年   200篇
  2014年   292篇
  2013年   402篇
  2012年   237篇
  2011年   266篇
  2010年   295篇
  2009年   419篇
  2008年   253篇
  2007年   207篇
  2006年   247篇
  2005年   230篇
  2004年   151篇
  2003年   184篇
  2002年   157篇
  2001年   205篇
  2000年   150篇
  1999年   206篇
  1998年   213篇
  1997年   232篇
  1996年   337篇
  1995年   284篇
  1994年   216篇
  1993年   131篇
  1992年   173篇
  1991年   183篇
  1990年   105篇
  1989年   171篇
  1988年   146篇
  1987年   118篇
  1986年   147篇
  1985年   124篇
  1984年   116篇
  1983年   99篇
  1982年   86篇
  1981年   75篇
  1980年   91篇
  1979年   65篇
  1978年   77篇
  1977年   62篇
  1976年   65篇
  1975年   71篇
  1964年   53篇
  1963年   52篇
排序方式: 共有9282条查询结果,搜索用时 15 毫秒
31.
The elderly (age >65 years) are more vulnerable to side-effects induced by non-steroidal anti-inflammatory drugs (NSAIDs). We therefore performed a double-blind comparative study of ketoprofen SR and sulindac in patients with active rheumatoid arthritis, 65 years of age or older. Sulindac was chosen because of its possible renal sparing effects, and ketoprofen SR because of its short half life and sustained release delivery system. Eighty patients were entered. More patients withdrew from the study due to side-effects in the sulindac group; both treatment groups had a high incidence of side-effects during this study and during previous exposure to other NSAIDs, demonstrating that the elderly are susceptible to side-effects from NSAIDs.  相似文献   
32.
Ventricular vagal nerve endings are thought to trigger vasodepressor syncope. Reports of vasodepressor reactions associated with donor bradycardia after cardiac transplantation have led to speculation that vagal reinnervation occurs. We assessed reinnervation status in seven patients 23–36 months (median 24 months) post-transplantation. Heart rate responses to vagal manoeuvres (respiration, Valsalva) and sympathetic stimuli (exercise and injection of tyramine into the coronary artery supplying the sinus node) were measured. All patients underwent 60 min of 60° head-up tilt with foot plate support. During tilt four of the seven had vasodepressor reactions with a fall in mean arterial pressure of 20–90 mmHg. During vasodepression two patients had falls in donor heart rate of 13 and 40% relative to peak heart rate during tilt. These two patients had evidence of functional sympathetic reinnervation. By contrast the two patients without donor bradycardia during vasodepression had only limited or no evidence of sympathetic reinnervation. No patient had consistent evidence of parasympathetic reinnervation as judged by the heart rate response to vagal manoeuvres. Headup tilt can thus produce vasodepressor reactions with donor bradycardia after cardiac transplantation in the absence of consistent evidence of vagal reinnervation. Left ventricular nerve endings may not be the only mediators of tilt-induced vasodepressor reactions in man. Donor bradycardia during vasodepression may reflect sympathetic withdrawal and not vagal reinnervation.  相似文献   
33.
A double-blind randomised study was performed to assess the value of the addition of pethidine 50 mg to the initial dose of bupivacaine given for epidural analgesia in labour. Forty-nine patients received either 1 ml of saline (n = 24), or 50 mg of pethidine (n = 25), added to 9 ml of 0.25% bupivacaine as an initial injection for intrapartum epidural analgesia. There was a significant increase in the mean duration of analgesia in the pethidine group. However, pethidine did not increase the speed of onset of analgesia, or improve the quality of analgesia.  相似文献   
34.
S. L. Lim  MB  BS  MMed    D. H. B. Tay  MB  BS  MMed  FAMS    E. Thomas  MB  BS  MMed  FANZCA  FAMS   《Anaesthesia》1994,49(3):255-257
  相似文献   
35.
SUMMARY Four specialised air mattresses had interface pressure measured under six body sites prone to pressure sores in 10 subjects, supine and sitting. The mattresses were the Clinirest (SSI) and FirstStep (KCI) continuous airflow mattress overlays, and Airwave (Pegasus) and Nimbus (Huntleigh) alternating pressure air mattresses. On the mattress overlays, average supine interface pressures were 2.33 kPa (scapula), 4.15 kPa (elbow), 1.94 kPa (sacrum) and 2.79 kPa (buttock), although they were higher at the occiput (7.97 kPa) and heel (11.7 kPa). The alternating pressure air mattresses had an average minimum interface pressure close to zero for three sites, rising to 4.28 kPa under the heel. Average maximum interface pressures were 8.61 kPa (occiput), 5.21 kPa (scapula), 4.90 (elbow), 4.85 kPa (sacrum), 4.61 kPa (buttock) and 13.2 kPa (heel). No accepted scientific method exists for comparing the two types of mattress. Our data suggest a clinical benefit at the occiput and heel (supine) in using an alternating pressure air mattress and a benefit in using a continuous airflow mattress overlay at other sites.  相似文献   
36.
Before informed advice can be given to parents and health care workers about the need for pertussis immunisation, an estimate of the risk of inadequately immunised children contracting pertussis is needed. The study reported here was conducted because the literature contains no such estimates of risk. Analysis was made of a county's Notification of Disease Reports. Computation was carried out of age-specific annual notification rates of pertussis amongst adequately and inadequately immunised children. It was found that inadequately immunised one-year-old children probably have more than a one in six chance of developing pertussis before age ten.  相似文献   
37.
A randomized controlled trial of sedation in the critically ill   总被引:2,自引:0,他引:2  
A randomized controlled trial comparing: a) a combination of oral chloral hydrate and promethazine to b) a continuous intravenous midazolam infusion, for maintenance sedation in critically ill children, was carried out. The level of sedation was assessed four hourly using a specifically devized sedation scale. Forty-four children entered the study of whom two were subsequently excluded. The number of satisfactory assessments (desired and actual levels of sedation equal) was significantly greater in the chloral hydrate and promethazine group (Chi-squared P <0.01; confidence intervals of the difference 0.06 to 0.20). The number of assessments at level 5 on the sedation scale (patient restless/distressed) was significantly greater in the midazolam group (Chi-squared P <0.05). The total number of satisfactory assessments in the two groups were only 61 and 48% respectively, suggesting that sedation can be considerably improved. Chloral hydrate and promethazine are more effective than midazolam as maintenance sedation in critically ill children. It is possible to prospectively study the efficacy of sedative drugs in critically ill children.  相似文献   
38.
A survey by questionnaire was carried out to examine the level of nursing staff satisfaction with the acute psychiatric services. Comparisons were made between views of older psychiatric hospitals and newer district general hospital units, and before and after the closure of Friern Barnet Hospital, London, England when the service was reorganized to include fewer beds. The importance of nurses having their say is emphasized, and areas in which improvements can be made are suggested.  相似文献   
39.
Mary A. Moxon  MB  ChB  FFARCS    M.E. Ward  MB  BS  FFARCS 《Anaesthesia》1986,41(5):543-546
An operating theatre fire and the steps taken to deal with it are described; the difficulties encountered in evacuating anaesthetised patients are highlighted. Measures which might be taken to prevent recurrence of these problems, and recommendations on the institution of fire drills for the safety of patients and staff are given.  相似文献   
40.
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