全文获取类型
收费全文 | 230篇 |
免费 | 73篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 12篇 |
妇产科学 | 6篇 |
基础医学 | 33篇 |
口腔科学 | 2篇 |
临床医学 | 15篇 |
内科学 | 54篇 |
皮肤病学 | 10篇 |
神经病学 | 17篇 |
特种医学 | 58篇 |
外科学 | 24篇 |
综合类 | 14篇 |
预防医学 | 19篇 |
眼科学 | 5篇 |
药学 | 23篇 |
肿瘤学 | 12篇 |
出版年
2022年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 11篇 |
2000年 | 2篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 15篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 19篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1970年 | 4篇 |
1968年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有304条查询结果,搜索用时 15 毫秒
51.
52.
53.
Parenteral nutrition may protect patients unable to eat from malnutrition almost indefinitely. If fat is not also given EFAD will occur. This outlines a prospective study of 28 surgical patients on total intravenous fat-free nutrition to determine the developmental course of EFAD and the response to therapy. Twenty-eight patients ranging from newborn to 66 years receiving parenteral nutrition without fat had regular determinations of the composition of total plasma fatty acids and the triene/tetraene ratio using gas liquid chromatography. Physical signs of EFAD were looked for also. Patients found to have evidence of EFAD were treated with 10% Intralipid. Topical safflower oil was used in three infants. Total plasma fatty acid composition was restudied following therapy. In general, infants on fat-free intravenous nutrition developed biochemical EFAD within two weeks, but dermatitis took longer to become evident. Older individuals took over four weeks to develop a diagnostic triene/tetraene ratio (greater than 0.4; range 0.4 to 3.75). Therapeutic correction of biochemical EFAD took 7 to 10 days but dermatitis took longer to correct. Cutaneous application of safflower oil alleviated the cutaneous manifestations but did not correct the triene/tetraene ratio of total plasma fatty acids. These studies indicate that surgical patients who are unable to eat for two to four weeks, depending upon age and expected fat stores, should receive fat as a part of their intravenous regimen. 相似文献
54.
漫反射光谱法研究维生素C与片剂辅料的相互作用 总被引:2,自引:0,他引:2
漫反射是一束光射到一定厚度的不透明不光滑固体表面上,光被部分吸收和部分散射后,向各个方向的反射。反射光的分数称为反射率。测定反射率时一般与某种白色粉末(例如硫酸钡)相比较,测得的反射率为相对反射率。以相对反射率对波长作图所得的曲线称为漫反射光 相似文献
55.
A comparison was made between untreated McCoy cells and McCoy cells treated with Cytochalasin B for the isolation of chlamydiae of subgroup A. Chlamydiae were isolated in both cell systems from 125 specimens, whereas six agents were isolated only in untreated cultures and seven agents were isolated only in Cytochalasin B treated cultures. 相似文献
56.
57.
58.
Blood flow imaging with MR: spin-phase phenomena 总被引:2,自引:0,他引:2
Blood flow phenomena occurring when flow is within the magnetic resonance (MR) imaging plane were analyzed. In this situation, the signal intensity of vascular lumina is predominantly determined by spin-phase change phenomena, and section transition effects of moving spins can be neglected. In this paper, we develop the concepts of in-plane flow, with emphasis on the notion that the spatial variations in velocity and acceleration of blood, which mainly occur along vessel walls, are important determinants of intravascular signal loss in MR images. Flow patterns in the large mediastinal arteries were qualitatively and quantitatively analyzed in six healthy subjects and 14 patients with hemodynamic abnormalities using multiple electrocardiograph-gated image acquisition; ungated studies of 30 patients were analyzed for venous flow effects. Intraluminal signal was strongly dependent on the phase of the cardiac cycle and the echo number. Signal loss was found to occur along vessel walls, in vascular bends, and at bifurcations. 相似文献
59.
60.