全文获取类型
收费全文 | 2778439篇 |
免费 | 205252篇 |
国内免费 | 4264篇 |
专业分类
耳鼻咽喉 | 38127篇 |
儿科学 | 90574篇 |
妇产科学 | 74124篇 |
基础医学 | 412058篇 |
口腔科学 | 77221篇 |
临床医学 | 251236篇 |
内科学 | 536805篇 |
皮肤病学 | 61869篇 |
神经病学 | 216811篇 |
特种医学 | 103889篇 |
外国民族医学 | 552篇 |
外科学 | 417621篇 |
综合类 | 58021篇 |
现状与发展 | 12篇 |
一般理论 | 963篇 |
预防医学 | 215346篇 |
眼科学 | 65174篇 |
药学 | 208172篇 |
12篇 | |
中国医学 | 6211篇 |
肿瘤学 | 153157篇 |
出版年
2021年 | 22265篇 |
2019年 | 22720篇 |
2018年 | 31457篇 |
2017年 | 23751篇 |
2016年 | 26609篇 |
2015年 | 29957篇 |
2014年 | 42180篇 |
2013年 | 63343篇 |
2012年 | 86701篇 |
2011年 | 91829篇 |
2010年 | 54658篇 |
2009年 | 51661篇 |
2008年 | 86316篇 |
2007年 | 92004篇 |
2006年 | 93071篇 |
2005年 | 89748篇 |
2004年 | 86179篇 |
2003年 | 82695篇 |
2002年 | 80326篇 |
2001年 | 129448篇 |
2000年 | 132642篇 |
1999年 | 111229篇 |
1998年 | 31846篇 |
1997年 | 27810篇 |
1996年 | 28207篇 |
1995年 | 26722篇 |
1994年 | 24593篇 |
1993年 | 23129篇 |
1992年 | 85971篇 |
1991年 | 83918篇 |
1990年 | 81717篇 |
1989年 | 79102篇 |
1988年 | 72741篇 |
1987年 | 71249篇 |
1986年 | 66876篇 |
1985年 | 63815篇 |
1984年 | 47417篇 |
1983年 | 40277篇 |
1982年 | 23653篇 |
1979年 | 43580篇 |
1978年 | 30960篇 |
1977年 | 25849篇 |
1976年 | 24751篇 |
1975年 | 26632篇 |
1974年 | 31874篇 |
1973年 | 30431篇 |
1972年 | 28514篇 |
1971年 | 26931篇 |
1970年 | 25101篇 |
1969年 | 23735篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
971.
972.
973.
Dr. Arthur A. Dunk MRCP Natasha Kyprianou MSc Peter Davies PhD Howard C. Thomas PhD FRCP 《Digestive diseases and sciences》1988,33(4):472-476
Castrated or sham-operated male athymic mice were inoculated with cells from the human hepatocellular carcinoma cell line PLC/PRF/5. There were no significant differences between the two groups with respect to the number of animals developing tumors, the time to tumor development, or the subsequent rate of increase in either tumor base area or mouse serum alpha-fetoprotein concentration. Androgen receptors were assayed in nuclei obtained from three separate liver cancer cell lines and from normal adult human liver. Similar concentrations, ranging from 235 to 550 fmol/mg DNA, of nuclear androgen receptors were detected in all tissues. Low percentages of androgen receptors were retained on DNA-cellulose. Although the presence of receptors implies the potential for metabolic effects of androgens in normal and malignant liver, our in vivostudies suggest that castration does not alter significantly the growth of liver cancer xenografts in athymic mice. 相似文献
974.
Dr. William A. Shaver MD Patrick Storms MD Dr. Walter L. Peterson MD 《Digestive diseases and sciences》1988,33(2):185-188
We have noted that colons of patients prepared for colonoscopy with Golytely, a nonabsorbable electrolyte lavage solution, frequently contain foam which may obscure small mucosal lesions. Therefore, a randomized, blinded controlled trial was performed to determine the prevalence of Golytely-induced foam and the effect of supplemental simethicone in decreasing the prevalence of foam. Foam was present in 32% of colons prepared with Golytely alone but in none of the colons prepared with Golytely supplemented with simethicone. In addition, only 5% of colons prepared with supplemental simethicone had residual stool noted at the time of colonoscopy, a significant improvement over the 39% prevalence of residual stool in colons prepared with Golytely alone. Addition of simethicone to Golytely lavage decreases the prevalence of colonic foam and residual stool. 相似文献
975.
976.
977.
P V Fragola C Autore G Ruscitti A Picelli M Borzi D Cannata M Sangiorgi 《Giornale italiano di cardiologia》1988,18(1):52-54
Eighty-nine first-degree relatives of 22 patients with an established diagnosis of hypertrophic cardiomyopathy underwent electrocardiographic and echocardiographic screening. Scalar electrocardiogram was abnormal in 30/89 (33.7%) relatives. Of these thirty, eleven had definite evidence of hypertrophic cardiomyopathy at echo; one had borderline hypertrophy and was considered neither affected nor unaffected; four had questionable signs of hypertrophy. The remaining 14 relatives had normal echo-cardiograms. Fifty-nine relatives (66.3%) had normal electrocardiograms; at echo 3 were considered to have borderline hypertrophy, 16 had questionable signs of hypertrophy and 40 were normal. In relatives of patients with hypertrophic cardiomyopathy an abnormal electrocardiogram may reflect different morphologic conditions: a real hypertrophic cardiomyopathy or a myocardial hypertrophy of uncertain significance. Furthermore, in these categories of subjects, an abnormal electrocardiogram with normal echo must be considered with caution. 相似文献
978.
G N J Tytgat 《Acta chirurgica. Supplement》2002,(587):77-81
A true comparison of long-term medical and surgical treatment in gastro-oesophageal reflux disease (GORD) is impossible as few studies have been carried out with adequate randomisation of the patients and long-term evaluation of quality of life. In general the control of the reflux symptoms is roughly equal with medical and surgical treatment. However, surgery can cause other symptoms such as dysphagia or non-specific epigastric discomfort or pain in some patients, which reduces the overall efficacy in controlling the symptoms. Based on a cost utility analysis, Heudebert et al. came to the conclusion that medical treatment was their preferred strategy for most patients with severe erosive oesophagitis. 相似文献
979.
980.