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   9331篇
  免费   711篇
  国内免费   42篇
耳鼻咽喉   90篇
儿科学   225篇
妇产科学   305篇
基础医学   1262篇
口腔科学   200篇
临床医学   1154篇
内科学   2181篇
皮肤病学   100篇
神经病学   771篇
特种医学   309篇
外科学   1133篇
综合类   113篇
一般理论   13篇
预防医学   730篇
眼科学   177篇
药学   694篇
中国医学   5篇
肿瘤学   622篇
  2023年   70篇
  2022年   37篇
  2021年   187篇
  2020年   158篇
  2019年   162篇
  2018年   211篇
  2017年   180篇
  2016年   157篇
  2015年   250篇
  2014年   307篇
  2013年   456篇
  2012年   675篇
  2011年   683篇
  2010年   369篇
  2009年   353篇
  2008年   581篇
  2007年   656篇
  2006年   644篇
  2005年   598篇
  2004年   581篇
  2003年   519篇
  2002年   563篇
  2001年   92篇
  2000年   84篇
  1999年   116篇
  1998年   123篇
  1997年   113篇
  1996年   98篇
  1995年   93篇
  1994年   70篇
  1993年   66篇
  1992年   65篇
  1991年   73篇
  1990年   51篇
  1989年   46篇
  1988年   41篇
  1987年   36篇
  1986年   43篇
  1985年   38篇
  1984年   39篇
  1983年   27篇
  1982年   57篇
  1981年   28篇
  1980年   29篇
  1979年   28篇
  1978年   26篇
  1977年   33篇
  1976年   18篇
  1975年   26篇
  1973年   19篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
1.
2.
3.
OBJECTIVE: To determine if there is a diurnal pattern in the clinical symptoms of HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets) syndrome. STUDY DESIGN: A retrospective study was performed in 134 pregnancies complicated by HELLP syndrome. The medical records were reviewed to describe each HELLP episode. Time of day was divided into three periods, day, evening, and night. The following parameters were categorized according to the time of day: onset of symptoms, consultation by the doctor, initial blood sampling, diagnosis and decrease of symptoms. Biochemical parameters at clinical presentation and consecutive changes within 24 h were recorded. RESULTS: In 65 pregnancies 77 HELLP episodes were well documented. Times of onset of symptoms and consultation by the doctor were significantly higher during the evening and night (p < 0.001), whereas times of diagnosis and decrease of symptoms occurred significantly more during the day (p < 0.001). In only 49.3% of the cases were diagnostic laboratory criteria met at clinical presentation. This was mainly due to platelet values in excess of 100 x 10(9)/l. Several hours later (median 8 h, range 2-23) the decrease in platelets occurred. CONCLUSIONS: A diurnal pattern exists in the clinical symptoms of HELLP syndrome that is characterized by an exacerbation during the night and recovery during the day. There is a considerable delay between the onset of symptoms and the fulfillment of diagnostic laboratory criteria.  相似文献   
4.
5.
6.
7.
8.
BACKGROUND: The impact of exercise programmes for heart failure on those close to the patient is largely unknown. We examined the effect of a hospital and home-based exercise intervention on burden, anxiety and depression of informal caregivers. DESIGN: The study was a randomized, controlled trial. Heart failure patients were randomized to a seated 12-week hospital-based exercise programme. Caregiver measures were gathered at baseline, 3 months later and 6 months following baseline. METHODS: Sixty caregivers (mean age 63.4 years, 65% female) of heart failure patients (n = 82, mean age 80.5 years, 44% female) participating in a trial of an exercise intervention were recruited. Caregiver burden, anxiety and depression were assessed. RESULTS: There were no differences in caregiver burden, depression or anxiety between the two groups of caregivers at baseline (caregiver burden, patient control 33.1 versus patient exercise 34.1; anxiety 4.1 versus 5.5; depression 2.8 versus 3.8). At 3 months there were no differences between caregivers in the two groups on outcomes. At 6-month follow-up caregivers of heart failure patients in the exercise group had burden scores that were significantly worse than the control group. There were no differences between the carers of exercise and control groups in anxiety and depression. Levels of anxiety and depression in the entire carer sample were marginally higher than reference values in a healthy non-clinical sample. CONCLUSION: The present exercise interventions for frail older patients did not benefit caregivers and was associated with an increase in caregiver burden. We suggest that future exercise interventions for heart failure patients should actively incorporate informal caregivers into research designs.  相似文献   
9.
Milieu relationships provide the critical background presence to staff's attempts to motivate, regulate, and teach patients how to cope with stress. Forging a connection with hospitalized children and adolescents demands attention to how they respond to adults and engage with staff around milieu expectations. Assessment guides that deal with these issues are presented. Important aspects of children's relatedness are presented in the context of their working models of adults and the influence of these representations on their response to staff. Coping skills are explained with particular emphasis on behavioral coping strategies. Tied to the assessment process are interventions that emphasize staff's role in helping patients manage strong affects and avoid the use of nonproductive behavior regulation strategies.  相似文献   
10.
Described in 1981 by the Chinese authors Yang Kuofan et al. [1] as a free flap, then in 1982 by Lu et al. [2] as a retrograde flow pedicle flap, this fasciocutaneous flap is designed at the level of the anterior and external faces of the forearm, and vascularized by the radial artery via a network of septal arteries. Prior to utilization it must be reversed on its distal pedicle. This flap allows repairing cutaneous substance loss of the whole hand and fingers. The emergence of the Chinese flap in the 1980’s resulted in a regression of the Mac Gregor groin flap that was widely used at this time [3,4]. Nevertheless, other forearm flaps, less “expensive” in terms of vascular involvement [5–9] have reduced its indications. The Chinese flap however keeps two essential indications: the multi-finger important defect that no other forearmflapmay cover; and composite substance loss of the thumb (despite the fact that the Chinese flap shares these indications with interosseous artery composite flaps).  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