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   54489篇
  免费   4252篇
  国内免费   119篇
医药卫生   58860篇
  2023年   506篇
  2022年   748篇
  2021年   1600篇
  2020年   965篇
  2019年   1507篇
  2018年   1762篇
  2017年   1290篇
  2016年   1362篇
  2015年   1447篇
  2014年   2028篇
  2013年   2966篇
  2012年   4195篇
  2011年   4301篇
  2010年   2278篇
  2009年   1994篇
  2008年   3603篇
  2007年   3562篇
  2006年   3322篇
  2005年   3230篇
  2004年   2927篇
  2003年   2608篇
  2002年   2488篇
  2001年   461篇
  2000年   358篇
  1999年   432篇
  1998年   519篇
  1997年   395篇
  1996年   343篇
  1995年   356篇
  1994年   302篇
  1993年   267篇
  1992年   256篇
  1991年   261篇
  1990年   229篇
  1989年   227篇
  1988年   223篇
  1987年   201篇
  1986年   215篇
  1985年   237篇
  1984年   221篇
  1983年   183篇
  1982年   190篇
  1981年   208篇
  1980年   166篇
  1979年   161篇
  1978年   129篇
  1977年   107篇
  1974年   129篇
  1973年   99篇
  1972年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc.  相似文献   
82.
Treatment of AtT-20 cell cultures with increasing concentrations of rat/human corticotropin-releasing factor (r/hCRF) for 24 h resulted in a dose-dependent 2-3 fold increase in specific 125I-labelled recombinant human IL-1 alpha (125I-IL-1 alpha) binding that was paralleled by a 70-80% decrease in 125I-Tyro-ovine CRF binding. Saturation analysis of 125I-IL-1 alpha binding in control and CRF-treated cultures indicated that CRF produced an increase in the density (Bmax) of IL-1 receptors without altering their affinity (KD). The CRF-induced upregulation of IL-1 receptors appears to be mediated through specific membrane receptors for CRF since the CRF receptor antagonist, alpha-helical oCRF (9-41), blocked the CRF-induced upregulation of IL-1 receptors without producing any effect on 125I-IL-1 alpha binding by itself. In summary, these data demonstrate complex interactions between CRF and IL-1 at the pituitary level and identify potential novel mechanisms for cytokines to alter neuroendocrine function.  相似文献   
83.
OBJECTIVE: To describe the rationale, methodology, and general sample characteristics of the Canadian Psychiatric Association (CPA) practice profile survey, a national survey of psychiatrists and psychiatric practice. METHOD: Mail-in interviews were sent to all Canadian psychiatrists listed in their provincial registers and to all active CPA members (total = 3628). Respondents provided general information about their professional activities for one 24-hour day and detailed information for 1 randomly selected hour. Patient information--including sociodemographics, diagnostic profiles, functioning levels, risk of harm to self or others, and disposition--was elicited for 1 patient seen during the random hour as well as for the most seriously ill patient receiving clinical services that day. RESULTS: There was a 45.5% response rate. Questionnaires completed by nonpsychiatrists or with a large percentage of missing or incorrect data were eliminated (107 surveys), resulting in a final sample size of 1570. CPA members and those from Western Canada responded at a higher rate to the survey. The results suggest some cause for concern about future manpower shortages. Most psychiatrists practise eclectically, seeing patients across the life-span, and working in both community and institutional settings. The old and the young appear to be underserviced, compared with adults. CONCLUSIONS: This study represents an important step forward in evaluating the profile and activities of the profession.  相似文献   
84.
85.
86.
Amputations of the nose and of the auricle present difficult management problems. Application of simple reattachment techniques, followed by aggressive medical therapy which consists of cooling, anticoagulation, antibiotic coverage, and multiple stab incisions in the amputated tissues, have resulted in the successful replantation of major portions of an amputated nose and an amputated auricle with satisfactory cosmetic results.  相似文献   
87.
The presence of collateral vessels in a young child with glaucoma is rare. The authors describe a case of collateral vessel regression with intraocular pressure reduction in a child with primary congenital glaucoma. Six months following 180 degrees goniotomies in each eye, the intraocular pressure was reduced, dilation of the retinal arteries and veins resolved, and collateral vessels in both eyes regressed. Intraocular pressure reduction may lead to the regression of collateral vessels in children with primary congenital glaucoma.  相似文献   
88.
During a five year period, approximately 150 elderly patients were treated with a water vapor and oxygen permeable membrane (VPM) in an open fashion. The following is important when treating elderly patients with VPM: xerosis or irritant dermatitis must be thoroughly treated before use of VPM as it will not adhere to abnormal skin; alcohol or acetone should not be used to prepare the treatment site as they cause irritation; VPM must not be stretched prior to placement as friction blisters occur in fragile, elderly skin; prior to removal, VPM should be soaked in soapy water or its surface rubbed lightly with alconol to break the adhesive bond to prevent stripping off epidermis; in patients with protein-calorie malnutrition, serum albumin should be monitored as large amounts of protein-rich fluid collect under VPM. VPM is a useful non-surgical approach to treating many ulcers in the elderly. Certain precautions must be taken to achieve optimum success in this population.  相似文献   
89.
90.
1. A heat-sink calorimeter, suitable for the measurement of energy expenditure in human subjects over periods up to 26 h, is described. 2. The performance of the calorimeter is illustrated by a study of four normal subjects at rest or performing clerical work for a period of 7.5 h. Each condition was measured in duplicate in each subject. On the resting days the subjects were recumbent, and on the working days they were seated throughout the measurement period. Heart rate was monitored by infra-red telemetry and physical activity by an ultrasound movement detector. Urinary cortisol excretion was also measured as an indicator of stress. 3. In each subject the mean heat loss on working days was higher than that on resting days: the increase ranged from 5.1% to 16.7%, with a mean value of 10.0% (P = 0.015). There was no significant difference between resting and working days in heart rate, physical activity or urinary cortisol excretion. 4. The present study confirms that tiring clerical work has very little effect on 24 h energy expenditure.  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-23

京公网安备 11010802026262号