全文获取类型
收费全文 | 1172篇 |
免费 | 58篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 71篇 |
妇产科学 | 21篇 |
基础医学 | 173篇 |
口腔科学 | 11篇 |
临床医学 | 156篇 |
内科学 | 293篇 |
皮肤病学 | 26篇 |
神经病学 | 79篇 |
特种医学 | 61篇 |
外科学 | 113篇 |
综合类 | 23篇 |
预防医学 | 54篇 |
眼科学 | 2篇 |
药学 | 58篇 |
中国医学 | 7篇 |
肿瘤学 | 58篇 |
出版年
2022年 | 14篇 |
2021年 | 24篇 |
2020年 | 12篇 |
2019年 | 18篇 |
2018年 | 28篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 28篇 |
2014年 | 43篇 |
2013年 | 68篇 |
2012年 | 70篇 |
2011年 | 53篇 |
2010年 | 29篇 |
2009年 | 33篇 |
2008年 | 42篇 |
2007年 | 40篇 |
2006年 | 58篇 |
2005年 | 37篇 |
2004年 | 39篇 |
2003年 | 39篇 |
2002年 | 33篇 |
2001年 | 32篇 |
2000年 | 35篇 |
1999年 | 24篇 |
1998年 | 19篇 |
1997年 | 25篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 14篇 |
1988年 | 25篇 |
1987年 | 20篇 |
1986年 | 15篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1968年 | 5篇 |
1952年 | 16篇 |
1951年 | 23篇 |
排序方式: 共有1236条查询结果,搜索用时 31 毫秒
1.
2.
Access to good-quality health services is crucial for the improvement of many health outcomes, such as those targeted by the
Millennium Development Goals (MDGs) adopted by the international community in 2000. The health-related MDGs cannot be achieved
if vulnerable populations do not have access to skilled personnel and to other necessary inputs. This paper focuses on the
geographical dimension of access and on one of its critical determinants: the availability of qualified personnel. The objective
of this paper is to offer a better understanding of the determinants of geographical imbalances in the distribution of health
personnel, and to identify and assess the strategies developed to correct them. It reviews the recent literature on determinants,
barriers and the effects of strategies that attempted to correct geographical imbalances, with a focus on empirical studies
from developing and developed countries. An analysis of determinants of success and failures of strategies implemented, and
a summary of lessons learnt, is included. 相似文献
3.
Intracranial venous thrombosis has been described in newborns, but there have been no reports of intractable neonatal seizures due to this condition. We report cortical venous sinus thrombosis in two term neonates who presented with seizures in the first 24 hours of life. The diagnosis was made by cranial computed tomography and was confirmed by cerebral angiography. Both patients improved clinically after the intracranial venous thrombosis resolved. These patients demonstrate that intracranial venous thrombosis should be considered in the differential diagnosis of neonatal seizures. 相似文献
4.
用体外培养的人的伪表皮作为模型,进行药物毒理学作用的研究,观察了二甲亚砜(DMSO)在不同浓度和不同接触时间条件下,对人的伪表皮细胞脱氧核糖核酸(DNA)、核糖核酸(RNA)和蛋白质合成的影响:随着接触时间的延长,DNA、RNA和蛋白质合成均受抑制。低浓度条件下(1%),DNA、RNA和蛋白质合成增加;在15~50%浓度下,DNA和蛋白质合成抑制,而RNA合成仍增加;在高浓度条件下(70%~100%),DNA、RNA和蛋白质合成均明显抑制。 相似文献
5.
6.
7.
8.
9.
The ramification of the portal vein at the porta hepatis was studied by anatomic dissection performed in 32 formalin fixed human livers. In all the specimens there were branches which ran towards the caudate lobe, arising from the portal vein and either from the left or the right portal branches. Tri-and quadrifurcation of the portal vein was observed. In 5 cases (16%) there were branches arising from left portal branch or portal vein and directed anteriorly to the quadrate lobe or to the region of the gall-bladder sulcus. These branches ranged from 1.0 to 6.0 mm in diameter. The portal caudate branches were divided into 3 groups.Group 1: Branches to the papillary process; 1 or 2 branches in 26 cases (82%), 3 or 5 branches in 3 cases (9%) and no branches in 3 cases (9%); 相似文献
10.
Hueber DM Franceschini MA Ma HY Zhang Q Ballesteros JR Fantini S Wallace D Ntziachristos V Chance B 《Physics in medicine and biology》2001,46(1):41-62
The frequency-domain multiple-distance (FDMD) method is capable of measuring the absolute absorption and reduced scattering coefficients of optically turbid media. Absolute measurement of absorption at two near-infrared (NIR) wavelengths makes possible the quantitation of tissue haemoglobin concentration and tissue haemoglobin oxygen-saturation (StO2). However, errors are introduced by the uncertainties of background absorption and the dissimilarities between real tissues and the simplified mathematical model on which these measurements are based. An FDMD-based tissue instrument has been used for the monitoring of tissue haemoglobin concentration and oxygenation in the brain of newborn piglets during periods of hypoxia and hyperoxia. These tissue haemoglobin saturation values were compared with arterial saturation (SaO2) and venous saturation (SvO2) measured by blood gas analyses. A linear correlation was observed between StO2 and the average of SaO2 and SvO2. However, StO2 is not equal to any fixed weighted average of SaO2 and SvO2 unless we introduce an effective background tissue absorption. The magnitude of the background absorption was about 0.08 cm(-1) at 758 nm and 0.06 cm(-1) at 830 nm, and it was nearly consistent between piglets. The origin of this 'effective' background absorption may be real, an artefact caused by the application of a simplified model to a complex sample, or a combination of factors. 相似文献