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   11704篇
  免费   797篇
  国内免费   45篇
耳鼻咽喉   106篇
儿科学   312篇
妇产科学   321篇
基础医学   1609篇
口腔科学   249篇
临床医学   1244篇
内科学   2674篇
皮肤病学   105篇
神经病学   958篇
特种医学   441篇
外科学   1401篇
综合类   177篇
一般理论   13篇
预防医学   1029篇
眼科学   278篇
药学   900篇
中国医学   6篇
肿瘤学   723篇
  2023年   68篇
  2022年   78篇
  2021年   211篇
  2020年   150篇
  2019年   199篇
  2018年   215篇
  2017年   176篇
  2016年   153篇
  2015年   253篇
  2014年   314篇
  2013年   511篇
  2012年   789篇
  2011年   776篇
  2010年   433篇
  2009年   388篇
  2008年   699篇
  2007年   780篇
  2006年   726篇
  2005年   710篇
  2004年   699篇
  2003年   622篇
  2002年   649篇
  2001年   181篇
  2000年   180篇
  1999年   189篇
  1998年   151篇
  1997年   127篇
  1996年   108篇
  1995年   128篇
  1994年   88篇
  1993年   96篇
  1992年   127篇
  1991年   136篇
  1990年   114篇
  1989年   101篇
  1988年   95篇
  1987年   85篇
  1986年   89篇
  1985年   90篇
  1984年   75篇
  1983年   51篇
  1982年   70篇
  1981年   43篇
  1980年   43篇
  1979年   53篇
  1978年   51篇
  1977年   42篇
  1976年   38篇
  1973年   46篇
  1969年   41篇
排序方式: 共有10000条查询结果,搜索用时 640 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.
Wound healing involves a number of cellular and molecular events, many of which are controlled by soluble growth factors. In the process of healing, hepatocyte growth factor, a cytokine known to act as mitogen, motogen, and morphogen, has been postulated to play multiple roles during several stages of this complex biological process. Produced primarily by stromal fibroblasts, hepatocyte growth factor regulates angiogenesis, vascular permeability, cell migration, matrix deposition and degradation, and other biological processes. The current article discusses recent progress in understanding the multiple roles played by this growth factor in tissue repair.  相似文献   
5.
6.
7.
8.
9.
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   
10.
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