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   15751篇
  免费   921篇
  国内免费   195篇
耳鼻咽喉   202篇
儿科学   375篇
妇产科学   414篇
基础医学   2173篇
口腔科学   281篇
临床医学   1734篇
内科学   2155篇
皮肤病学   510篇
神经病学   1122篇
特种医学   1737篇
外科学   2989篇
综合类   52篇
预防医学   1041篇
眼科学   406篇
药学   1089篇
中国医学   90篇
肿瘤学   497篇
  2023年   141篇
  2021年   105篇
  2020年   136篇
  2019年   98篇
  2018年   310篇
  2017年   294篇
  2016年   352篇
  2015年   247篇
  2014年   427篇
  2013年   647篇
  2012年   764篇
  2011年   1130篇
  2010年   674篇
  2009年   481篇
  2008年   858篇
  2007年   968篇
  2006年   980篇
  2005年   774篇
  2004年   661篇
  2003年   680篇
  2002年   586篇
  2001年   468篇
  2000年   542篇
  1999年   388篇
  1998年   249篇
  1997年   246篇
  1996年   334篇
  1995年   297篇
  1994年   218篇
  1993年   133篇
  1992年   141篇
  1991年   157篇
  1990年   96篇
  1989年   152篇
  1988年   126篇
  1987年   95篇
  1986年   117篇
  1985年   113篇
  1984年   108篇
  1983年   96篇
  1982年   95篇
  1981年   91篇
  1980年   109篇
  1979年   68篇
  1978年   87篇
  1977年   54篇
  1976年   62篇
  1975年   71篇
  1964年   53篇
  1963年   66篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
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   
22.
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   
23.
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   
24.
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.  相似文献   
25.
Childhood sarcoidosis is a rare disorder with protean manifestations. The case of a child with prolonged fever, hepatosplenomegaly, pancytopenia, and systemic necrotizing vasculitis manifesting as fever, rash and skin infarctions, digital pregangrene, and foot drop is reported. This is the first case of systemic necrotizing vasculitis reported in sarcoidosis. The fulminant course of the disease required treatment with intravenous pulsed cyclophosphamide and high doses of corticosteroids. The spectrum of vasculitis in childhood and adult sarcoidosis is reviewed.  相似文献   
26.
From mid-October 1989 to mid-July 1990 all newly admitted residents to Bury Local Authority Residential Homes were comprehensively medically screened. In a series of 100 residents eight had early Parkinson's disease (six of them hitherto undiagnosed). Seven showed evidence of Vitamin C deficiency. Of the seven showing evidence of deficiency, four suffered from early Parkinson's disease. Of the 93 without evidence of Vitamin C deficiency only four had Parkinson's disease. This indicates a significantly higher prevalence of Parkinson's disease in the group with Vitamin C deficiency (P less than 0.001 using Fisher's exact).  相似文献   
27.
28.
29.
M. J. Ball  BSc  MB  BCh  MRCP    J. W. Sear  BSc  PhD  FFARCS  DRCOG   《Anaesthesia》1986,41(4):423-426
Critically ill patients are usually in a catabolic state and may require total parenteral nutrition; this often includes lipid emulsions. Any adverse effects of constituents on pulmonary function, white cell function or the haemocoagulation system could have disastrous consequences in such patients. We have investigated the effects of a new intravenous lipid preparation containing medium chain triglycerides, which, in severely ill malnourished patients are theoretically a preferable energy source to conventional drug chain triglycerides. In a pilot study 17 critically ill patients whose lungs were artificially ventilated were given this lipid emulsion; no adverse effects were observed. Arterial oxygen and carbon dioxide tensions, ratio of inspired oxygen fractional concentration to arterial oxygen tension, platelet and white cell counts all remained constant and the complement system was not activated.  相似文献   
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