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   1143篇
  免费   116篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   46篇
妇产科学   24篇
基础医学   96篇
口腔科学   11篇
临床医学   121篇
内科学   230篇
皮肤病学   20篇
神经病学   52篇
特种医学   109篇
外科学   246篇
综合类   40篇
预防医学   68篇
眼科学   20篇
药学   52篇
中国医学   1篇
肿瘤学   122篇
  2023年   9篇
  2022年   8篇
  2021年   15篇
  2020年   22篇
  2019年   23篇
  2018年   21篇
  2017年   23篇
  2016年   24篇
  2015年   22篇
  2014年   40篇
  2013年   40篇
  2012年   44篇
  2011年   50篇
  2010年   47篇
  2009年   52篇
  2008年   38篇
  2007年   48篇
  2006年   36篇
  2005年   46篇
  2004年   35篇
  2003年   32篇
  2002年   36篇
  2001年   38篇
  2000年   31篇
  1999年   22篇
  1998年   22篇
  1997年   21篇
  1996年   20篇
  1995年   17篇
  1994年   19篇
  1993年   21篇
  1992年   30篇
  1991年   19篇
  1990年   18篇
  1989年   18篇
  1988年   24篇
  1987年   30篇
  1986年   19篇
  1985年   27篇
  1984年   14篇
  1983年   10篇
  1982年   8篇
  1981年   8篇
  1980年   11篇
  1979年   11篇
  1977年   13篇
  1975年   11篇
  1973年   6篇
  1970年   7篇
  1966年   5篇
排序方式: 共有1267条查询结果,搜索用时 125 毫秒
1.
2.
3.
4.
青蒿琥酯皮肤擦剂在小鼠和兔体内的药代动力学研究   总被引:1,自引:0,他引:1  
赵凯存  宣文漪  赵一  宋振玉 《药学学报》1989,24(11):813-816
将青蒿琥酯溶于苯二甲酸二甲酯,加适量氨酮制成皮肤擦剂。给兔脱毛后,皮肤涂抹此擦剂25mg/kg后,血药浓度达峰时间平均为2 h,峰浓度平均为1.80μg/ml。药物在兔体内平均驻留时间为3.54 h,清除半衰期约为2.46 h。给小鼠脱毛皮肤涂抹擦剂6.7,31.3和71.4 mg/kg,血药浓度在给药后0.5~4 h达高峰,峰浓度分别为0.82,2.05和7.11μg/ml,体内药物平均驻留时间为3.39,2.79及3.54 h,清除半衰期为2.35,1.93及2.45 h。可见,给兔及小鼠皮肤擦剂后,青蒿琥酯吸收良好,血药浓度维持时间较长。  相似文献   
5.
Perceptions and definitions of the term family have always been varied and complex. Hence, an overview of contemporary families is presented here from several perspectives. First, families as they have been perceived by nursing and social science theorists are reviewed. Demographic changes in the family over the last two decades are then presented, followed by an examination of issues faced by families as they change over time. Finally, families as they exist within varying cultural and social contexts are discussed. Emphasis is placed on the need for health care providers to be flexible in defining and working with individual patients and their families.  相似文献   
6.
7.
8.
BACKGROUND: Left ventricular ejection fraction (LVEF) is a significant predictor of morbidity and death. The nuclear summed rest score (SRS) measures myocardial perfusion defects and provides prognostic information, but its effects on long-term outcomes are not fully established. Moreover, information regarding the potential interaction between these 2 covariates is limited. The purpose of this study was to determine whether the mortality risk associated with LVEF is the same across all values of SRS in a population undergoing evaluation for ischemic heart disease. METHODS AND RESULTS: We examined 3,187 patients who underwent cardiac catheterization and perfusion single photon emission computed tomography imaging with a maximum follow-up of 8.1 years and median follow-up of 3.1 years. Cox proportional hazards modeling showed that increasing nuclear SRS and decreasing LVEF were independently associated with a higher long-term mortality rate, with a clinically significant interaction between them (P = .032). Patients with a normal LVEF and a high SRS (greater perfusion abnormality) have a prognosis similar to those with a reduced LVEF. CONCLUSIONS: Resting perfusion studies provide prognostic information for long-term survival and significantly impact the interpretation of mortality risk associated with changes in LVEF. Patient prognostication, risk stratification, and future research using these variables should take this interaction into account.  相似文献   
9.
Background  Left ventricular ejection fraction (LVEF) is a significant predictor of morbidity and death. The nuclear summed rest score (SRS) measures myocardial perfusion defects and provides prognostic information, but its effects on long-term outcomes are not fully established. Moreover, information regarding the potential interaction between these 2 covariates is limited. The purpose of this study was to determine whether the mortality risk associated with LVEF is the same across all values of SRS in a population undergoing evaluation for ischemic heart disease. Methods and Results  We examined 3,187 patients who underwent cardiac catheterization and perfusion single photon emission computed tomography imaging with a maximum follow-up of 8.1 years and median follow-up of 3.1 years. Cox proportional hazards modeling showed that increasing nuclear SRS and decreasing LVEF were independently associated with a higher long-term mortality rate, with a clinically significant interaction between them (P=.032). Patients with a normal LVEF and a high SRS (greater perfusion abnormality) have a prognosis similar to those with a reduced LVEF. Conclusions  Resting perfusion studies provide prognostic information for long-term survival and significantly impact the interpretition of mortality risk associated with changes in LVEF. Patient prognostication, risk stratification, and future research using these variables should take this interaction into account. Supported by a grant from the Tom & Lynn Royster Foundation. Durham, NC, and a National Institutes of Health Research Fellowship Grant (T5 GM08679-04), Bethesda, Md.  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