首页 | 官方网站   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   152974篇
  免费   32735篇
  国内免费   2408篇
医药卫生   188117篇
  2024年   515篇
  2023年   4810篇
  2022年   1184篇
  2021年   3171篇
  2020年   6073篇
  2019年   2250篇
  2018年   7492篇
  2017年   7413篇
  2016年   8519篇
  2015年   8546篇
  2014年   15628篇
  2013年   15832篇
  2012年   5734篇
  2011年   5769篇
  2010年   10513篇
  2009年   14371篇
  2008年   5979篇
  2007年   4218篇
  2006年   6705篇
  2005年   3952篇
  2004年   3178篇
  2003年   2186篇
  2002年   2224篇
  2001年   3851篇
  2000年   3066篇
  1999年   3249篇
  1998年   3677篇
  1997年   3486篇
  1996年   3376篇
  1995年   3223篇
  1994年   1956篇
  1993年   1571篇
  1992年   1405篇
  1991年   1444篇
  1990年   1083篇
  1989年   1195篇
  1988年   1049篇
  1987年   858篇
  1986年   901篇
  1985年   734篇
  1984年   564篇
  1983年   536篇
  1982年   517篇
  1981年   402篇
  1980年   360篇
  1979年   317篇
  1978年   337篇
  1977年   405篇
  1975年   285篇
  1972年   296篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
991.
992.
993.
994.
Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied.  相似文献   
995.
Palmar advancement flap with V-Y closure for thumb tip injuries   总被引:1,自引:0,他引:1  
The palmar advancement flap with V-Y closure was used in two patients with thumb tip injuries. This technique allows more distal advancement of the flap than does a conventional palmar advancement flap and does not require skin graft coverage.  相似文献   
996.
We examined records of sedations provided by the paediatric anaesthesiology staff for 455 children (ages 1 mo-17 yr) undergoing MRI or CT scans at our institution over a twelve-month period with regard to the monitoring of adverse events: excessive sedation, agitation, vomiting, hypoxaemia, and major airway compromise. One hundred-and-thirty-one patients (29%) received chloral hydrate; 324 patients (71%) received propofol. All patients were monitored with continuous noninvasive pulse oximetry and received supplemental oxygen via nasal cannulae. Of the patients who received chloral hydrate, 64 (49%) were over one year of age; of the patients who received propofol, 318 (98%) were one year of age or older. In the chloral hydrate group, 23 patients (19%) were deemed excessively sedated and four patients (3%) were agitated; no patients in the propofol group experienced any of the adverse outcomes reviewed. Furthermore, no patients in either group had significant airway compromise and none was admitted to the hospital as a result of the sedation.  相似文献   
997.
Urban and Rural Differences in Health Insurance and Access to Care   总被引:3,自引:0,他引:3  
This study considers differences in access to health care and insurance characteristics between residents of urban and rural areas. Data were collected from a telephone survey of 10,310 randomly selected households in Minnesota. Sub-samples of 400 group-insured, individually insured, intermittently insured, and uninsured people, were asked about access to health care. Those with group or individual insurance were also asked about the costs and characteristics of their insurance policies.
Rural areas had a higher proportion of uninsured and individually insured respondents than urban areas. Among those who purchased insurance through an employer, rural residents had fewer covered benefits than urban residents (5.1 vs 5.7, P < 0.01) and were more likely to have a deductible (80% versus 40%, P < 0.01). In spite of this, rural uninsured residents were more likely to have a regular source of care than urban residents (69% versus 51%, P < 0.01), and were less likely to have delayed care when they thought it was necessary (21% versus 32%, P<0.01). These differences were confirmed by multivariate analysis.
Rural residents with group insurance have higher out-of-pocket costs and fewer benefits. Uninsured rural residents may have better access to health care than their urban counterparts. Attempts to expand access to health care need to consider how the current structure of employment-based insurance creates inequities for individuals in rural areas as well as the burdens this structure may place on rural providers.  相似文献   
998.
Reversal of diastolic cerebral blood flow in infants without brain death   总被引:1,自引:0,他引:1  
The reversal of diastolic cerebral blood flow has been regarded as a characteristic waveform of brain death and a useful confirming sign. We report 2 patients who had diastolic flow reversal but survived. One, a 1-month-old boy with status epilepticus, had reversal of diastolic cerebral blood flow detected by Doppler ultrasound soon after admission. Reversal disappeared after medical management for increased intracranial pressure and seizure control. He recovered without sequelae. The other, a 6-month-old girl with choroid plexus papilloma, had reversal of diastolic flow during abrupt clinical deterioration. Emergent surgical removal of the tumor was performed and she survived with hemiparesis and psychomotor retardation. Our patients demonstrated that even in the presence of diastolic reversal of cerebral blood flow, prompt and effective treatment can avoid a fatal outcome.  相似文献   
999.
1000.
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-23

京公网安备 11010802026262号