全文获取类型
收费全文 | 8289篇 |
免费 | 675篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 295篇 |
妇产科学 | 269篇 |
基础医学 | 1157篇 |
口腔科学 | 92篇 |
临床医学 | 1335篇 |
内科学 | 1331篇 |
皮肤病学 | 131篇 |
神经病学 | 726篇 |
特种医学 | 181篇 |
外科学 | 777篇 |
综合类 | 121篇 |
一般理论 | 22篇 |
预防医学 | 1142篇 |
眼科学 | 254篇 |
药学 | 614篇 |
中国医学 | 11篇 |
肿瘤学 | 499篇 |
出版年
2023年 | 92篇 |
2022年 | 43篇 |
2021年 | 228篇 |
2020年 | 186篇 |
2019年 | 285篇 |
2018年 | 305篇 |
2017年 | 237篇 |
2016年 | 249篇 |
2015年 | 272篇 |
2014年 | 358篇 |
2013年 | 500篇 |
2012年 | 688篇 |
2011年 | 684篇 |
2010年 | 369篇 |
2009年 | 319篇 |
2008年 | 517篇 |
2007年 | 562篇 |
2006年 | 505篇 |
2005年 | 517篇 |
2004年 | 475篇 |
2003年 | 453篇 |
2002年 | 357篇 |
2001年 | 72篇 |
2000年 | 45篇 |
1999年 | 68篇 |
1998年 | 90篇 |
1997年 | 66篇 |
1996年 | 45篇 |
1995年 | 50篇 |
1994年 | 45篇 |
1993年 | 50篇 |
1992年 | 20篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 9篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 6篇 |
1982年 | 17篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1970年 | 5篇 |
1969年 | 6篇 |
排序方式: 共有8980条查询结果,搜索用时 656 毫秒
31.
32.
33.
Fiona E. Ralley J. Earl Wynands James G. Ramsay Franco Carli Roisin MacSullivan 《Journal canadien d'anesthésie》1988,35(4):332-337
Oxygen consumption (VO2), carbon dioxide production (VCO2), end-tidal carbon dioxide partial pressure (PETCO2), mixed venous oxygen saturation (SvO2) and haemodynamic variables were recorded every 30 min for four hours in 15 patients recovering from hypothermic cardiopulmonary bypass (CPB). All patients had been anaesthetised with fentanyl 40 micrograms.kg-1, supplemented with isoflurane, and pancuronium 0.15 mg.kg-1 for muscle relaxation. Three of the 15 patients (20 per cent) shivered, defined as intermittent or continuous, vigorous movements of chest or limb muscles. Patients who shivered had a VO2 of 159 +/- 16.4 ml.min-1.m-2 on arrival in the ICU which rose to a maximum value of 254 +/- 28.3 ml.min-1.m-2 by 150 min post-CPB. In contrast, patients who did not shiver had a significantly lower VO2 of 93.1 +/- 6.9 ml.min-1.m-2 on arrival in the ICU which rose to a maximal value of only 168 +/- 11.5 ml.min-1.m-2 by 180 min post-CPB. Maximal VO2 in both groups was reached when the nasopharyngeal temperature (NPT) was approaching normal. VCO2 paralleled the increase in VO2 in both groups. By four hours there was no significant difference between the two groups; however, the VO2 in both groups (160.5 +/- 21.3 ml.min-1.m-2 and 173.9 +/- 12.3 ml.min-1.m-2 respectively) was approximately twice values commonly measured in anaesthetized patients. Patients who shivered had a significantly higher heart rate and cardiac index and significantly lower SvO2. We conclude that the high VO2 and VCO2 associated with shivering causing increased myocardial work may be detrimental to patients who have impaired cardiac function post-coronary artery surgery (CAS). 相似文献
34.
35.
NHS Direct usage in a GP population of children under 5 years: is NHS Direct used by people with the greatest health need? 下载免费PDF全文
This study compares health status, demographic and socioeconomic characteristics of users and non-users of NHS Direct in order to establish whether the service is being used by people with the greatest need for healthcare services. It suggests that use of NHS Direct is widespread among carers of children under 5 years old, but there is evidence that it may not be accessed equitably by those from ethnic minorities, lower socioeconomic groups and those with established ill health. 相似文献
36.
BACKGROUND: To investigate vergence adaptation during the incipient phase of presbyopia, when the amplitude of accommodation approaches the level where the first reading addition is required. The study aimed to assess the ability of the vergence system to counteract changes in the component contributions to the overall vergence response with the decline in the amplitude of accommodation in presbyopia, although previous reports on the nature of changes in accommodative, tonic and proximal vergence are equivocal. METHODS: Using a 'flashed' Maddox rod technique, an assessment of vergence adaptation to 6delta base-out and 6delta base-in prism was made for 28 subjects (aged 35-45 years at the commencement of the study). The measurements were taken four times over a 2-year period. RESULTS: Using a repeated measures analysis of variance, the results show that with the decline in amplitude of accommodation, there is a statistically significant reduction in the magnitude of vergence adaptation to both base-out (p < 0.05) and base-in prism (p < 0.01). CONCLUSIONS: This study shows that with ageing, there is a decrease in the ability of the slow vergence mechanism to overcome a change in fusional vergence demand and would suggest that either the fast component of fusional vergence must cope with any change in fusional vergence demand or that the sum of the accommodative, tonic and proximal vergence responses are virtually stable with age. 相似文献
37.
38.
39.
40.
Reliability of a Core Competency Checklist Assessment in the Emergency Department: The Standardized Direct Observation Assessment Tool 总被引:2,自引:1,他引:1