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   360篇
  免费   44篇
  国内免费   4篇
儿科学   26篇
妇产科学   1篇
基础医学   39篇
口腔科学   9篇
临床医学   63篇
内科学   72篇
皮肤病学   13篇
神经病学   12篇
特种医学   78篇
外科学   27篇
综合类   6篇
预防医学   29篇
眼科学   3篇
药学   13篇
  2篇
肿瘤学   15篇
  2023年   4篇
  2020年   3篇
  2019年   5篇
  2018年   8篇
  2017年   6篇
  2016年   7篇
  2015年   7篇
  2014年   12篇
  2013年   18篇
  2012年   11篇
  2011年   6篇
  2010年   14篇
  2009年   19篇
  2008年   10篇
  2007年   7篇
  2006年   9篇
  2005年   4篇
  2004年   9篇
  2003年   4篇
  2002年   9篇
  2001年   10篇
  2000年   3篇
  1999年   9篇
  1998年   19篇
  1997年   20篇
  1996年   17篇
  1995年   19篇
  1994年   15篇
  1993年   11篇
  1992年   4篇
  1991年   7篇
  1990年   8篇
  1989年   10篇
  1988年   5篇
  1987年   8篇
  1986年   7篇
  1985年   9篇
  1984年   5篇
  1983年   9篇
  1982年   3篇
  1981年   1篇
  1980年   5篇
  1979年   6篇
  1978年   7篇
  1977年   5篇
  1976年   7篇
  1975年   4篇
  1967年   1篇
  1958年   2篇
排序方式: 共有408条查询结果,搜索用时 15 毫秒
21.
Overheating may cause terminal apnoea and cot death. Rectal temperature and breathing patterns were examined in normal infants at home during the first 6 months of life. Twenty one infants had continuous overnight rectal temperature and breathing recordings for 429 nights (mean 20.4 nights, range 7-30) spaced over the first six months of life. Periods when breathing was 'regular' were directly marked on single night records. Sleep state was determined from respiratory variables. 'Regular' breathing was a reliable marker of 'quiet' sleep (specificity 93%). The duration of 'quiet' sleep increased from 6 to 22 minutes from two weeks to three months of age and then remained static, as did the proportion of sleep spent in the quiet phase (9% to 34%). Rectal temperature fell during 66% of quiet sleep and usually rose during rapid eye movement (REM) sleep. The drop in rectal temperature was maximal at the start of quiet sleep, whereas the maximum rise during REM sleep was reached after 10 to 15 minutes. Oscillations in rectal temperature are associated with changes in sleep and breathing state. The maturation of rectal temperature patterns during the first six months of life are closely related to a maturation of sleep state and breathing patterns.  相似文献   
22.
Immunoglobulin G subclass concentrations were measured in paired foetal (cord) and maternal serum specimens at delivery from 27 IgA-deficient (serum IgA < 0.01 g/l) and 15 control women. IgA-deficient women had significantly higher serum IgGl and IgG3 concentrations than control women but 2 of the group had concomitant IgG2/IgG4 deficiency and a further 12 had low IgG4 concentrations (serum IgG4 < 0.025 g/l). Foetal serum also had significantly higher IgGl concentrations than control foetal serum but lower IgG2 and IgG4 levels. Concentrations of IgG subclasses and IgM were measured in breast milk collected on the fifth day postpartum from 19 of these IgA-deficient and 18 control women. Between-group differences in IgG subclass levels resembled those in serum. Compared with serum, proportionally less IgG3 was present in milk in both groups although the contribution of IgG3 to total IgG was not less than that of IgG4. Slightly higher IgM was found in milk from the IgA-deficient mothers.  相似文献   
23.
Magnetic resonance imaging of benign mediastinal masses   总被引:1,自引:0,他引:1  
  相似文献   
24.
25.
Multisection, dual-echo magnetic resonance (MR) transaxial images of blood vessels contain both anatomic and qualitative information about flow. Even so, the images are produced as a series of two-dimensional tomographic sections from which full visualization of connected structures is difficult. A computer algorithm was developed that automatically detects flowing blood based on pixel intensity and calculated T2 and provides reconstructed views of vessels while analyzing and displaying flow characteristics. Images of abdominal vessels, aortic aneurysms, and the heart were encoded by flow and color to demonstrate depth. In addition, these data were reconstructed to derive a more accurate assessment of patency. With this technique, transaxial images can be used to analyze flow patterns, determine patent areas, and visualize all levels of vessels in a single image.  相似文献   
26.
27.
28.
论我国医疗美容产业的可持续发展   总被引:4,自引:1,他引:3  
目的探讨我国医疗美容事业的产业化属性、经济学地位,以及如何达到全面、协调和可持续发展的大目标。方法逻辑论证。结果认识到医疗美容产业是“医疗美容经济”系统的核心要素;揭示了医疗美容产业具有“人本经济”的特征,民营医疗美容产业是发展医疗美容事业的重要力量,医疗美容产业的发展是当代中国医学美学与美容医学整体学科建设和发展的社会基础和经济基础。结论医疗美容产业的形成是医疗美容事业在社会主义市场经济条件下发展的必然趋势,同时提出了医疗美容产业健康发展的三大措施:增强产业意识;加强行业规范;实行人本管理。最终的结论是:医疗美容事业利用产业化机制,走产业化发展的道路,促进了整个社会医疗美容事业的全面、协调和可持续发展。  相似文献   
29.
30.
Sensory neurons that innervate the heart sense ischemia and mediate angina. To use patch-clamp methods to study ion channels on these cells, we fluorescently labeled cardiac sensory neurons (CSNs) in rats so that they could later be identified in dissociated primary culture of either nodose or dorsal root ganglia (DRG). Currents evoked by a variety of different agonists imply the importance of lowered pH (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