全文获取类型
收费全文 | 3734篇 |
免费 | 269篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 85篇 |
妇产科学 | 53篇 |
基础医学 | 523篇 |
口腔科学 | 55篇 |
临床医学 | 453篇 |
内科学 | 827篇 |
皮肤病学 | 43篇 |
神经病学 | 253篇 |
特种医学 | 238篇 |
外科学 | 712篇 |
综合类 | 36篇 |
一般理论 | 2篇 |
预防医学 | 241篇 |
眼科学 | 44篇 |
药学 | 283篇 |
中国医学 | 4篇 |
肿瘤学 | 153篇 |
出版年
2023年 | 26篇 |
2022年 | 36篇 |
2021年 | 56篇 |
2020年 | 51篇 |
2019年 | 72篇 |
2018年 | 72篇 |
2017年 | 62篇 |
2016年 | 67篇 |
2015年 | 71篇 |
2014年 | 72篇 |
2013年 | 138篇 |
2012年 | 157篇 |
2011年 | 162篇 |
2010年 | 94篇 |
2009年 | 88篇 |
2008年 | 147篇 |
2007年 | 166篇 |
2006年 | 162篇 |
2005年 | 132篇 |
2004年 | 121篇 |
2003年 | 118篇 |
2002年 | 131篇 |
2001年 | 122篇 |
2000年 | 124篇 |
1999年 | 125篇 |
1998年 | 72篇 |
1997年 | 81篇 |
1996年 | 65篇 |
1995年 | 66篇 |
1994年 | 40篇 |
1993年 | 48篇 |
1992年 | 72篇 |
1991年 | 78篇 |
1990年 | 85篇 |
1989年 | 54篇 |
1988年 | 78篇 |
1987年 | 84篇 |
1986年 | 65篇 |
1985年 | 64篇 |
1984年 | 54篇 |
1983年 | 51篇 |
1982年 | 32篇 |
1981年 | 33篇 |
1980年 | 26篇 |
1979年 | 45篇 |
1978年 | 28篇 |
1977年 | 31篇 |
1975年 | 22篇 |
1971年 | 20篇 |
1970年 | 22篇 |
排序方式: 共有4021条查询结果,搜索用时 31 毫秒
1.
2.
Relation between energy expenditure and body composition in man: specific energy expenditure in vivo of fat and fat-free tissue 总被引:2,自引:0,他引:2
L Garby J S Garrow B J?rgensen O Lammert K Madsen P S?rensen J Webster 《European journal of clinical nutrition》1988,42(4):301-305
The relationship between energy expenditure and body composition, in terms of fat and fat-free masses, has previously been described by a variety of predictive regression equations with parameters devoid of physiological content. We present here results obtained by calculating the specific energy expenditure, ie, the energy expenditure per unit of mass, of fat and fat-free tissue on the basis of measurements of the total energy expenditure (EE), the masses of fat (FM), and fat-free (FFM) tissue using the following simple model: EE = k1.FM + k2.FFM where k1 and k2 are the specific energy expenditures of fat and fat-free tissue, respectively. The results of observations on 104 women at rest yielded values for k1 and k2 of 0.31 and 1.35 watts/kg of fat and fat-free mass, respectively, with standard errors of estimate of 0.074 and 0.052 watts/kg, respectively. Analysis of several series of measurements, from other sources and on smaller samples of subjects, yielded similar values at rest but with larger standard errors of estimate. Data from subjects performing varying amounts of work in 24-h measurements showed, as expected, larger values for both tissues. The results explain to a very large extent the well-established relation between resting metabolic rate and body weight, ie, a linear relation with a non-zero intercept. The results also offer a clear-cut explanation for the well known difference in energy expenditure between men and women with the same body weight. 相似文献
3.
Fixation of displaced femoral neck fractures: A comparison between sliding screw plate and four cancellous bone screws 总被引:1,自引:0,他引:1
Frank Madsen Frank Linde Erik Andersen Hanne Birke Inge Hvass Torben D. Poulsen 《Acta orthopaedica》1987,58(3):212-216
In a prospective, randomized trial, 104 consecutive patients with displaced femoral neck fractures were allocated either to fixation with a sliding screw plate or 4 ASIF cancellous bone screws. The patients were reexamined at fixed intervals to determine the time of union. The 2-year-cumulated rate of union was 64 per cent in the plate group and 84 per cent in the screw group. 相似文献
4.
F. Madsen 《Clinical and experimental allergy》2006,36(6):850-851
5.
6.
O A Madsen 《World health forum》1988,9(1):24-28
Health meassages have long been carried on stamps, cancellations and special envelopes. Some postal administrations are particularly active in using stamps as a medium for messages. Others seem to be quite inactive. Perhaps some health ministries, and other interested parties, have not fully understood the enormous potential for health education which exists here. Stamps and frankings can be a major inexpensive source of information about health and other subjects. If those interested in promoting health were to use the full potential of stamps for this purpose, health for all would be 1 step closer to being achieved. The accompanying illustrations show that the health message can take many forms. 相似文献
7.
Decreased blood perfusion in canine tibial diaphysis after filling with acrylic bone cement compared with inert bone wax 总被引:1,自引:0,他引:1
Sixteen dogs had one tibia filled with acrylic PMMA bone cement and the opposite, control tibia filled with inert bone wax. After 1, 4, and 12 weeks, the blood perfusion in diaphyses was measured with Sc-46 labeled microspheres. The blood flow rates increased from 1 to 4 weeks and dropped to about the 1-week level after 12 weeks on both sides, with the acrylic side lower than the control side. On both sides, Disulphine Blue staining of the bones showed severe endosteal avascularity after 1 and 4 weeks and massive periosteal apposition after 4 and 12 weeks. The initial increase in blood flow is considered due to periosteal apposition, and the differences in blood flow rates are attributed to avascularity caused by the polymerization heat and toxicity of the acrylic cement. 相似文献
8.
Experimental verification of a model for predicting transient temperature distributions by focused ultrasound 总被引:1,自引:0,他引:1
A thermal model for predicting time-dependent temperature distributions during ultrasound heating was tested quantitatively. The relevant thermal processes incorporated in the model are heat conduction and ultrasound power absorption, and the required input parameters include the absolute ultrasound power, the shape and frequency of the ultrasound transducer, and the thermal and acoustical properties of the medium. Testing was done by heating an ultrasonically tissue-mimicking phantom with a 525 kHz, single element, focused source. The phantom has muscle-like acoustical properties and contains an array of copper-constantan thermocouples. Time-dependent temperature changes predicted with the thermal model were in very good agreement with those measured in the phantom, verifying the validity of the model for use in optimizing an ultrasound applicator design for a specific treatment situation. 相似文献
9.
F. F. Madsen 《Acta neurochirurgica》1990,106(3-4):164-169
Summary Changes in regional cerebral blood flow in anaesthetized pigs with an induced focal cerebral contusion were studied before and after two grades of hyperventilation. A reduction in arterial tension of CO2 with 0.70mmHg and a further reduction of 0.55mmHg did not change the CO2 reactivity. Reactivity in both injured and macroscopically normal regions was the same, revealing an average of 39.3% flow change per kPa change in CO2 tension. Regions with low flow after the contusion had an equally big reduction apparently leading to hypoxia because global metabolic rate was unchanged. 相似文献