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   33800篇
  免费   2514篇
  国内免费   139篇
耳鼻咽喉   381篇
儿科学   891篇
妇产科学   437篇
基础医学   4300篇
口腔科学   671篇
临床医学   3152篇
内科学   7029篇
皮肤病学   504篇
神经病学   3673篇
特种医学   1602篇
外国民族医学   3篇
外科学   4996篇
综合类   871篇
一般理论   66篇
预防医学   2904篇
眼科学   631篇
药学   2073篇
  2篇
中国医学   52篇
肿瘤学   2215篇
  2023年   111篇
  2022年   184篇
  2021年   478篇
  2020年   284篇
  2019年   451篇
  2018年   593篇
  2017年   439篇
  2016年   503篇
  2015年   584篇
  2014年   893篇
  2013年   1406篇
  2012年   2115篇
  2011年   2253篇
  2010年   1249篇
  2009年   1209篇
  2008年   2130篇
  2007年   2272篇
  2006年   2248篇
  2005年   2415篇
  2004年   2136篇
  2003年   1969篇
  2002年   1989篇
  2001年   379篇
  2000年   302篇
  1999年   373篇
  1998年   505篇
  1997年   475篇
  1996年   443篇
  1995年   428篇
  1994年   331篇
  1993年   327篇
  1992年   258篇
  1991年   279篇
  1990年   258篇
  1989年   246篇
  1988年   229篇
  1987年   251篇
  1986年   205篇
  1985年   223篇
  1984年   255篇
  1983年   250篇
  1982年   295篇
  1981年   286篇
  1980年   243篇
  1979年   143篇
  1978年   163篇
  1977年   114篇
  1976年   134篇
  1975年   91篇
  1974年   110篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.

Background  

There are no published utilities for the post-anesthesia state obtained by the standard gamble method (SG).  相似文献   
8.
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country. It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS) with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery (OPCAB) in patients with critical left main stem stenosis. Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively. 10 patients were high risk with a Euro score of ≥5. Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding. There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion to CPB. There was no operative mortality. Inotropes were used in ten cases. Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may be managed by Beating heart On Pump (BHOP) technique.  相似文献   
9.
10.
OBJECTIVE: Neighborhood sociodemographic characteristics may be important to the mental health of older adults who have decreased mobility and fewer resources. Our objective was to examine the association between neighborhood context and level of depressive symptomatology in older adults in a diverse geographic region of central North Carolina. METHODS: The sample included 2,998 adults 65 or older residing in 91 census tracts. Depressive symptoms were measured using the Center for Epidemiologic Studies-Depression scale (CES-D). Neighborhoods were characterized by five census-based characteristics: socioeconomic disadvantage, socioeconomic advantage, racial/ethnic heterogeneity, residential stability, and age structure. RESULTS: In ecologic level analyses, level of census tract socioeconomic disadvantage was associated with increased depressive symptoms. To determine whether neighborhood context was associated with depressive symptoms independently of individual characteristics, the authors used multilevel modeling. The authors examined the ability of each of five neighborhood (level 2) characteristics to predict a level 1 outcome (CES-D symptoms) controlling for the effects of individual (level 1) characteristics. Younger age, being widowed, lower income, and having some functional limitations were associated with increased depression symptoms conditional on census tract random effects. However, none of the neighborhood characteristics was significantly associated with depression symptoms, conditional on census tract random effects, either unadjusted or adjusted for individual characteristics. CONCLUSION: Any observed association between neighborhood sociodemographic characteristics and individual depressive symptoms in our sample may reflect the characteristics of the individuals who reside in the neighborhood rather than the neighborhood characteristics themselves. The use of multilevel modeling is important to separate these effects.  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