全文获取类型
收费全文 | 841篇 |
免费 | 30篇 |
国内免费 | 31篇 |
专业分类
儿科学 | 1篇 |
基础医学 | 59篇 |
口腔科学 | 477篇 |
临床医学 | 25篇 |
内科学 | 31篇 |
皮肤病学 | 50篇 |
神经病学 | 4篇 |
特种医学 | 4篇 |
外科学 | 18篇 |
综合类 | 84篇 |
预防医学 | 14篇 |
眼科学 | 3篇 |
药学 | 73篇 |
中国医学 | 57篇 |
肿瘤学 | 2篇 |
出版年
2023年 | 13篇 |
2022年 | 17篇 |
2021年 | 22篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 27篇 |
2014年 | 39篇 |
2013年 | 57篇 |
2012年 | 50篇 |
2011年 | 52篇 |
2010年 | 41篇 |
2009年 | 36篇 |
2008年 | 41篇 |
2007年 | 56篇 |
2006年 | 28篇 |
2005年 | 30篇 |
2004年 | 25篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 23篇 |
2000年 | 13篇 |
1999年 | 15篇 |
1998年 | 8篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 7篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 13篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1985年 | 21篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 7篇 |
1975年 | 3篇 |
排序方式: 共有902条查询结果,搜索用时 15 毫秒
1.
2.
Controversial issues in the treatment of hyperkalaemia. 总被引:2,自引:2,他引:0
3.
1310 patients were routinely patch tested with a paratertiary-butylphenol-formaldehyde resin (PTBP-F-R), a resol resin based on phenol and formaldehyde (P-F-R-2), and a mixture of these 2 resins. Approximately 2.5 times more patients with contact allergy to phenol-formaldehyde resins were diagnosed when routinely patch tested with P-F-R-2 in addition to PTBP-F-R. Although patch testing with a mixture of both resins was not as good as patch testing with the 2 resins separately, it was better than testing only with PTBP-F-R, since 1.6 times more patients with contact allergy to phenol-formaldehyde resins were still diagnosed. P-F-R-2 is therefore recommended for routine patch testing, preferably as a separate patch test but otherwise as a mixture with PTBP-F-R. 相似文献
4.
用酸蚀法提高纯钛与光固化冠桥树脂粘结强度的研究 总被引:5,自引:1,他引:4
目的:研究用酸蚀法提高钛与光固化复合树脂剪切粘结强度的可行性,并观察表面粗糙度与剪切粘结强度之间的关系。方法:采用不同浓度的酸蚀剂对钛铸件表面进行酸蚀,并与artglass光固化复合树脂进行粘结,以单纯喷砂组为对照,比较剪切粘结强度的差异。对酸蚀后及剪切试验后的金属表面进行扫描电镜观察,并测定其表面粗糙度。结果:用酸蚀法可以显著提高钛与复合树脂的粘结强度,HF浓度为4%时粘结强度最高。表面粗糙度随酸蚀剂的浓度增高而下降。结论:纯钛铸件用酸蚀法处理后可以获得较高的粘结强度,HF酸浓度以4%为宜。表面粗糙度对粘结强度不起决定性作用。 相似文献
5.
Dr. R. Mordasini F. Twelsiek P. Oster B. Schellenberg H. Raetzer C. C. Heuck G. Schlierf 《Journal of molecular medicine (Berlin, Germany)》1978,56(16):805-808
Summary In 20 children and adolescents with familial Type IIa hyperlipoproteinemia, serum lipids and lipoproteins were examined before and during treatment with polyanion exchange resins. The composition of LDL was compared to that of healthy siblings. The patients were given Colestyramine (0.6 g/kg body weight) and Colestipol (0.5 g/kg body weight) in a cross-over study for 8 weeks each, after they had been under dietary treatment for at least 12 months. In 6 children, drug treatment had to be stopped due to side-effects. The most common complaints were gastrointestinal discomfort and constipation.Cholesterol, triglycerides and phopholipids were measured in whole serum and cholesterol, triglycerides and Apolipoprotein-B in isolated lipoprotein fractions after ultracentrifugation. Apo-B was determined by radial immunodiffusion.The Apo-B: cholesterol ratio in whole serum and in the LDL fraction was identical in the patients and in the controls. The LDL triglyceride: Apo-B ratio, however, was about 50% lower in the patients. This abnormal LDL composition was not altered by therapy with polyanion exchange resins. HDL cholesterol levels were significantly lower in the patients than in healthy children, and remained low during therapy.The decrease of total and LDL cholesterol (25%) and Apo-B (20%) was similar under both Colestipol and Colestyramine. Triglycerides and phospholipids showed no significant changes in therapy.These studies were supported by grants of the Schweizerische Nationalfonds and the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 90, Cardiovasculäres System) 相似文献
6.
Wayne D. Cook 《Biomaterials》1986,7(6):449-454
The spectral distributions of a range of dental photocuring sources were measured at the exit window and at a distance of 10 cm. The former enabled the evaluation of a newly proposed photocuring efficiency index which correlates well with the depth of cure of the photopolymerized resins, thus providing a basis for the comparison of different photocuring sources. The spectral irradiante of the sources obeyed the inversesquare law, allowing a comparison with the ACGIH threshold limit values. According to these criteria, no ocular hazard is posed to the patient or clinician by u.v.-A or u.v.-B radiation nor to the patient by the visible light when momentarily exposed to the sources. Similarly the ACGIH criterion indicates that the clinician does not risk chorioretinal injury provided the exposure is restricted to less than 140 s in a 3 h period. 相似文献
7.
The chemistry and structure of the dimethacrylate resins and the nature of the filler systems in dental composite resins are reviewed in relation to their influence on the setting behaviour, dimensional stability, aesthetics, fracture behaviour and adhesive potential. It is clear that a deeper understanding of the structure of the polymeric matrix and the mechanism of clinical wear is required. As a result of ongoing research in this area and with the development of dentine adhesives, the future prospects of composite resins are encouraging. 相似文献
8.
Preparation of Aminated Macroporous Polyvinyl Alcohol Resins and Evaluation for Bilirubin Adsorption
WANG Wei-chao ZHANG Sheng-nan HU Yue-han XIE Hui OU Lai-liang YU Yao-ting KONG De-ling GU Han-qing 《中国生物医学工程学报(英文版)》2008,17(3)
In the present study we prepared macroporous polyvinyl alcohol beads. A series of bilirubin adsorbents were generated by immobilization of eight amine agents to the beads as ligands. The adsorption of bilirubin was evaluated by in vitro static and dynamic adsorption tests. The results show that these adsorbents have excellent adsorption efficiency and capacity. Among the eight ligands, trimethylamine (TMA), triethylamine (TEA) and 1,6- hexanediamine(HDA) showed the highest adsorption capacity. The adsorption equilibrium can be achieved in half an hour, and the adsorption percentage of bilirubin was up to 80%. Static electricity and hydrophobic interaction played the main role in bilirubin adsorption, and the adsorption was found to match the monolayer model. The excellent adsorption of these adsorbents indicates their potential in clinical treatment. 相似文献
9.
离子交换树脂法与活性炭吸附法提取左旋多巴结果比较 总被引:2,自引:0,他引:2
以水和盐酸为溶剂从猫豆中提取左旋多巴,并对提取液分别用离子交换树脂法和活性炭吸附法富集左旋多巴,再分别用氨水和醇洗脱,经浓缩、精制得左旋多巴。实验结果表明,前法提取周期较长,平均提取率为2.50%,后法提取周期较短,平均提取率为2.66%,提示后法优于前法。 相似文献
10.
研究了以甲基丙烯酸酯端基不饱和取酯树脂为主链,用甲基丙烯酸甲酯取代苯乙烯作为交联剂制成的甲基丙烯酸酯树脂(MAER)与通用型不饱和聚酯树脂(GUPR)的热裂解机理、燃烧现象。结果表明:MAER的裂角产物中苯环化合物含量(14.9%)少于GUPR(74.5%)。MAER燃烧时的发烟量和毒性也远低于GUPR。在MAER中加入三水合氧化铝(ATH)后,裂解产物中有毒物质的各类和数量更少,在燃烧时只有少量 相似文献