全文获取类型
收费全文 | 5384篇 |
免费 | 386篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 177篇 |
儿科学 | 93篇 |
妇产科学 | 85篇 |
基础医学 | 790篇 |
口腔科学 | 245篇 |
临床医学 | 523篇 |
内科学 | 994篇 |
皮肤病学 | 57篇 |
神经病学 | 556篇 |
特种医学 | 210篇 |
外科学 | 688篇 |
综合类 | 23篇 |
一般理论 | 3篇 |
预防医学 | 496篇 |
眼科学 | 113篇 |
药学 | 329篇 |
中国医学 | 7篇 |
肿瘤学 | 385篇 |
出版年
2023年 | 59篇 |
2022年 | 50篇 |
2021年 | 92篇 |
2020年 | 95篇 |
2019年 | 147篇 |
2018年 | 131篇 |
2017年 | 123篇 |
2016年 | 105篇 |
2015年 | 108篇 |
2014年 | 128篇 |
2013年 | 203篇 |
2012年 | 299篇 |
2011年 | 281篇 |
2010年 | 149篇 |
2009年 | 151篇 |
2008年 | 256篇 |
2007年 | 235篇 |
2006年 | 226篇 |
2005年 | 235篇 |
2004年 | 211篇 |
2003年 | 172篇 |
2002年 | 162篇 |
2001年 | 179篇 |
2000年 | 150篇 |
1999年 | 112篇 |
1998年 | 54篇 |
1997年 | 38篇 |
1996年 | 50篇 |
1995年 | 43篇 |
1994年 | 37篇 |
1993年 | 38篇 |
1992年 | 88篇 |
1991年 | 101篇 |
1990年 | 118篇 |
1989年 | 103篇 |
1988年 | 68篇 |
1987年 | 86篇 |
1986年 | 77篇 |
1985年 | 66篇 |
1984年 | 65篇 |
1983年 | 47篇 |
1982年 | 43篇 |
1980年 | 33篇 |
1979年 | 61篇 |
1978年 | 37篇 |
1975年 | 35篇 |
1974年 | 38篇 |
1973年 | 31篇 |
1970年 | 35篇 |
1969年 | 29篇 |
排序方式: 共有5774条查询结果,搜索用时 78 毫秒
1.
Fronto-ethmoidal mucocoeles: a histopathological analysis. 总被引:1,自引:0,他引:1
From a series of 118 fronto-ethmoidal mucocoeles, 40 specimens have been submitted to detailed histological analysis. The frequency of each epithelial and sub-epithelial component is considered and reveals features which support a dynamic theory of bone resorption and formation rather than that of pressure erosion in the pathogenesis of mucocoeles. 相似文献
2.
Usher syndrome: clinical findings and gene localization studies 总被引:3,自引:0,他引:3
William J. Kimberling Sandra L. H. Davenport Ira Priluck Valorie White Karen Biscone-Halterman Patrick E. Brookhouser Claes G. Mller Gunnar Lund Timothy J. Grissom Michael D. Weston 《The Laryngoscope》1989,99(1):66-72
The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized. 相似文献
3.
MR imaging was reviewed in 66 pediatric spinal cord patients with diagnoses of posterior fossa tumor (n = 8), primary spinal cord tumor (n = 3), metastatic disease (n = 11), neuroectodermal disorder (n = 8), congenital malformation (n = 14), trauma (n = 2), and demyelinating, neurodegenerative, or metabolic disorders (n = 9). MR proved to be useful in delineating the extent of posterior fossa and cord tumor including metastasis to the cord. MR was of limited value in demyelinating and metabolic disorders. Arnold Chiari malformations, syringomyelia, tethered cord and meningoceles were all easily evaluated using MR. 相似文献
4.
5.
E K Lund W E Lee-Finglas S Southon J M Gee I T Johnson P M Finglas A J Wright 《European journal of clinical nutrition》1992,46(12):857-864
The relationship between dietary fat intake and fasting plasma lipid levels was assessed in 35 female and 19 male adolescents recruited from two local education authority schools in Norwich, UK. Dietary intakes were assessed using a 7-day weighed dietary record method, coupled with the collection of duplicate diets. Fat and energy intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Fasting plasma lipid levels (total, HDL and LDL cholesterol and triglycerides) were measured and compared with total dietary lipids and fatty acid intakes. The average proportion of energy consumed as fat was higher than is currently considered desirable but lower than previous studies have reported for adults. Mean serum total cholesterol values were 4.2 (SEM 0.1) mmol for females and 4.5 (SEM 0.2) mmol for males; this difference was not statistically significant. In male subjects the dietary fatty acid profiles were significantly correlated with several parameters of plasma lipid status which are thought to be risk factors for coronary heart disease, and in particular with the ratio of total:HDL cholesterol. 相似文献
6.
7.
8.
International comparisons show that populations having a high consumption of fish experience low incidence of breast cancer. We compared death rates from breast cancer among socioeconomic groups in a prospective study of 533,276 Norwegian women aged 35–54 years who were followed from 1970 through 1985. Compared with the reference group (wives of unskilled workers) the fishermen's wives had a decreased risk of breast cancer with a relative risk (RR) of 0.67 (95% confidence interval [CI]=0.47–0.94) adjusted for age and the number of children. Among fishermen's wives who were parous, adjustment for age at first birth gave an RR of 0.62 (CI=0.43–0.91). This study supports the hypothesis that certain aspects of diet, i. e., fish consumption, may be associated with lower breast-cancer mortality.Drs Lund and Bønaa are with the Institute of Community Medicine, University of Tromsø, Tromsø, Norway. Address correspondence to Dr Lund, Institute of Community Medicine, University of Tromsø, N-9037 Tromsø, Norway. 相似文献
9.
10.
L. Lund H. Henmar P. A. Würtzen G. Lund N. Hjortskov J. N. Larsen 《Clinical and experimental allergy》2007,37(4):564-571
BACKGROUND: Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens. OBJECTIVE: The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. METHODS: Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. RESULTS: IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice. CONCLUSION: While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid concept. 相似文献