全文获取类型
收费全文 | 1605379篇 |
免费 | 121517篇 |
国内免费 | 5471篇 |
专业分类
耳鼻咽喉 | 20737篇 |
儿科学 | 52128篇 |
妇产科学 | 45742篇 |
基础医学 | 228273篇 |
口腔科学 | 42894篇 |
临床医学 | 139228篇 |
内科学 | 323372篇 |
皮肤病学 | 38081篇 |
神经病学 | 131606篇 |
特种医学 | 60204篇 |
外国民族医学 | 482篇 |
外科学 | 233447篇 |
综合类 | 37726篇 |
现状与发展 | 7篇 |
一般理论 | 512篇 |
预防医学 | 131302篇 |
眼科学 | 36355篇 |
药学 | 114524篇 |
24篇 | |
中国医学 | 5518篇 |
肿瘤学 | 90205篇 |
出版年
2021年 | 14683篇 |
2019年 | 15337篇 |
2018年 | 23402篇 |
2017年 | 17832篇 |
2016年 | 18806篇 |
2015年 | 20823篇 |
2014年 | 27844篇 |
2013年 | 40364篇 |
2012年 | 57833篇 |
2011年 | 60336篇 |
2010年 | 34560篇 |
2009年 | 31864篇 |
2008年 | 53615篇 |
2007年 | 56642篇 |
2006年 | 56941篇 |
2005年 | 58953篇 |
2004年 | 57409篇 |
2003年 | 52818篇 |
2002年 | 47499篇 |
2001年 | 77153篇 |
2000年 | 79103篇 |
1999年 | 65154篇 |
1998年 | 18039篇 |
1997年 | 16241篇 |
1996年 | 16262篇 |
1995年 | 15422篇 |
1994年 | 13955篇 |
1993年 | 13005篇 |
1992年 | 47846篇 |
1991年 | 45263篇 |
1990年 | 43314篇 |
1989年 | 41098篇 |
1988年 | 37699篇 |
1987年 | 36743篇 |
1986年 | 34300篇 |
1985年 | 32639篇 |
1984年 | 24815篇 |
1983年 | 20844篇 |
1982年 | 12646篇 |
1981年 | 11192篇 |
1979年 | 21856篇 |
1978年 | 15342篇 |
1977年 | 12821篇 |
1976年 | 12075篇 |
1975年 | 12465篇 |
1974年 | 15057篇 |
1973年 | 14662篇 |
1972年 | 13714篇 |
1971年 | 12490篇 |
1970年 | 11876篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Erin C. Tully Jackson M. Gray Sherryl H. Goodman Stephen Nowicki Jr. 《Early child development and care》2016,186(12):1939-1951
Children who expect they can bring about good outcomes and avoid bad outcomes tend to experience more personal successes. Little is known about factors that contribute to these ‘control expectancies’. The purpose of the present study was to determine whether children's internal control expectancies occur in the context of parents’ internal control expectancies, low family strain, and high family cohesiveness and whether these factors are more strongly related to daughters’ than sons’ control expectancies. A community sample of 85 children aged 9–11 years and their parents (85 mothers; 63 fathers) completed rating scales. Fathers’ more internal control expectancies and mothers’ reports of fewer family strains were associated with daughters’ but not sons’ greater internal control expectancies, and greater family cohesiveness was related to both daughters’ and sons’ internal control orientations. These findings suggest that family factors may contribute to children's, particularly daughters’, development of internal control expectancies. 相似文献
22.
Dalton Luiz Schiessel Ricardo K. Yamazaki Marcelo Kryczyk Isabela Coelho de Castro Adriana A. Yamaguchi Danielle C. T. Pequito 《Nutrition and cancer》2016,68(8):1369-1380
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO. 相似文献
23.
Benyam Kinde Harrison W. Gabel Caitlin S. Gilbert Eric C. Griffith Michael E. Greenberg 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(22):6800-6806
DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system. 相似文献
24.
25.
Provocation of Atrial Fibrillation Triggers During Ablation: Does the Use of General Anesthesia Affect Inducibility? 下载免费PDF全文
26.
27.
T. Wu L. G. Trahair M. J. Bound C. F. Deacon M. Horowitz C. K. Rayner K. L. Jones 《Diabetic medicine》2015,32(5):595-600
28.
29.
Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study 下载免费PDF全文