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   43115篇
  免费   2934篇
  国内免费   269篇
医药卫生   46318篇
  2024年   67篇
  2023年   502篇
  2022年   970篇
  2021年   1378篇
  2020年   1120篇
  2019年   3141篇
  2018年   2747篇
  2017年   1613篇
  2016年   795篇
  2015年   868篇
  2014年   2434篇
  2013年   2135篇
  2012年   2388篇
  2011年   2518篇
  2010年   2108篇
  2009年   1743篇
  2008年   1646篇
  2007年   1419篇
  2006年   1351篇
  2005年   928篇
  2004年   770篇
  2003年   598篇
  2002年   428篇
  2001年   389篇
  2000年   321篇
  1999年   272篇
  1998年   221篇
  1997年   207篇
  1996年   150篇
  1995年   153篇
  1994年   129篇
  1993年   65篇
  1992年   28篇
  1991年   34篇
  1990年   29篇
  1988年   21篇
  1986年   21篇
  1985年   853篇
  1984年   1392篇
  1983年   1112篇
  1982年   1100篇
  1981年   1102篇
  1980年   955篇
  1979年   844篇
  1978年   660篇
  1977年   464篇
  1976年   632篇
  1975年   552篇
  1974年   469篇
  1973年   430篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
941.
Multigated equilibrium radionuclide angiography was used to quantitate global and regional ejection fraction (EF) in 26 awake dogs 10 minutes after distal and then proximal occlusion of the left anterior descending (LAD) or left circumflex (LC) coronary artery. Changes in global and regional EF were correlated with simultaneous measurements of the extent of acute left ventricular (LV) ischemia measured by radioisotope-labeled microspheres. The extent of ischemia, defined as the percentage of LV mass with greater than 25% reduction in blood flow from normal regional flow, was linearly related to the percent change in global EF after LAD (r = 0.84) and LC (r = 0.77) occlusions. The extent of ischemia also correlated with regional EF (r = 0.47 to 0.88 for LAD and r = 0.41 to 0.69 for LC occlusions). In 24 of 25 LAD occlusions and in all 20 LC occlusions that produced a measurable ischemic zone, the maximal percent change in regional EF exceeded the percent change in global EF. Two LAD occlusions and 2 LC occlusions reduced regional EF but not global EF. Thus, global and regional EF decreased in direct proportion to the extent of acute myocardial ischemia; regional ischemia produced greater changes in regional than in global EF.  相似文献   
942.
To elucidate the functional and prognostic significance of right ventricular dysfunction after acute inferior wall myocardial infarction, 74 consecutive patients with inferior infarction were prospectively evaluated with gated equilibrium blood pool imaging at rest, submaximal exercise thallium-201 scintigraphy and coronary angiography before hospital discharge. In addition, symptom-limited stress thallium-201 scintigraphy was performed in 61 patients at 3 months, and all patients were followed up clinically for 23 +/- 15 months. Utilizing predetermined radionuclide angiographic criteria, 47 patients (Group I) had normal right ventricular function, 12 patients (Group II) had mild to moderate dysfunction and 15 patients (Group III) had severe right ventricular dysfunction. There were no significant differences among the groups with regard to age, history of prior myocardial infarction, peak creatine kinase values, maximal Killip functional class, number or type of in-hospital complications, left ventricular ejection fraction, prevalence of multivessel disease or the distribution and severity of disease affecting the infarct-related vessel. Exercise tolerance as assessed by treadmill time, blood pressure-heart rate product and peak work load in METS was comparable among the three groups, both before hospital discharge and at 3 month follow-up. No differences in indicators of exercise-induced ischemia were noted among the groups, including the prevalence of redistribution thallium-201 defects, ST segment depression or symptoms of chest pain. Finally, cardiac mortality, reinfarction rate and the incidence of medically refractory angina pectoris were similar in the three groups. Thus, right ventricular dysfunction after acute inferior wall myocardial infarction does not appear to limit exercise tolerance or identify a subgroup of patients at higher risk for recurrent cardiac events.  相似文献   
943.
944.
945.
946.
947.
948.
949.
正手术室是一个特殊的工作场所,医护人员每天都要频繁地与患者的血液、体液、呕吐物和排泄物等接触,被锋利的污染医疗器械(如手术刀、缝针等)刺伤、划伤的概率也较高,以上情况都对医护人员的健康构成威胁。调查表明,手术室医护人员的职业预防现状不尽如人意,医护人员对标准预防及相关预防知识掌握欠缺。约40%的医护人员不了解针刺伤后应立即报告[1-2],43%的护理人员不知道针刺伤后应采取哪些  相似文献   
950.

Background

Improving the timely recognition and response to clinical deterioration is a critical challenge for clinicians, educators, administrators and researchers. Clinical deterioration leading to Rapid Response Team review is associated with poor patient outcomes. A range of factors associated with clinical deterioration and its outcomes have been identified, and may help with early identification of deteriorating patients. However, the relative importance of each factor on the development of clinical deterioration is unknown.

Objective

To identify the relative importance of factors contributing to the development of clinical deterioration in ward patients, as perceived by health professionals who have experience in recognising or responding to clinical deterioration, or in the management, administration or governance of RRSs.

Methods

A written questionnaire containing 12 pre-determined factors was provided to participants. Participants were asked to rank the items from most to least important contributors to ward patient deterioration. The study took place during a session of the Australia and New Zealand Intensive Care Society Rapid Response Team conference.

Results

A final sample of 233 (83% response rate), returned the questionnaire. The sample comprised specialist ICU registered nurses with direct patient contact (64%), ICU consultant doctors (17%), ICU nurse managers (7%), hospital administrators (2%), ICU registrars (2%), quality coordinators (2%) and non-hospital staff (4%). The patient’s presenting illness/main diagnosis was the highest ranked factor, followed by pre-existing co-morbidities, seniority of nursing ward staff, medical documentation, senior medical staff, and interdisciplinary communication. Almost two-thirds of participants ranked patient characteristics as the most important contributor to clinical deterioration.

Conclusion

Health professionals who have experience in recognising or responding to clinical deterioration, or in the management, administration or governance of RRSs perceive that patient characteristics such as the patient’s primary diagnosis and comorbidities to be the most important contributors to clinical deterioration.  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