全文获取类型
收费全文 | 133723篇 |
免费 | 9114篇 |
国内免费 | 551篇 |
专业分类
耳鼻咽喉 | 1400篇 |
儿科学 | 4022篇 |
妇产科学 | 2276篇 |
基础医学 | 17691篇 |
口腔科学 | 2522篇 |
临床医学 | 13353篇 |
内科学 | 27966篇 |
皮肤病学 | 1610篇 |
神经病学 | 12968篇 |
特种医学 | 4126篇 |
外国民族医学 | 1篇 |
外科学 | 19372篇 |
综合类 | 2023篇 |
现状与发展 | 1篇 |
一般理论 | 186篇 |
预防医学 | 11662篇 |
眼科学 | 3490篇 |
药学 | 9584篇 |
1篇 | |
中国医学 | 282篇 |
肿瘤学 | 8852篇 |
出版年
2023年 | 653篇 |
2022年 | 1117篇 |
2021年 | 2467篇 |
2020年 | 1502篇 |
2019年 | 2531篇 |
2018年 | 2956篇 |
2017年 | 2147篇 |
2016年 | 2482篇 |
2015年 | 2868篇 |
2014年 | 4190篇 |
2013年 | 5875篇 |
2012年 | 8884篇 |
2011年 | 9514篇 |
2010年 | 5194篇 |
2009年 | 4880篇 |
2008年 | 8446篇 |
2007年 | 8988篇 |
2006年 | 8510篇 |
2005年 | 8596篇 |
2004年 | 8102篇 |
2003年 | 7463篇 |
2002年 | 7179篇 |
2001年 | 1603篇 |
2000年 | 1257篇 |
1999年 | 1572篇 |
1998年 | 1583篇 |
1997年 | 1317篇 |
1996年 | 1055篇 |
1995年 | 1047篇 |
1994年 | 895篇 |
1993年 | 893篇 |
1992年 | 955篇 |
1991年 | 868篇 |
1990年 | 803篇 |
1989年 | 751篇 |
1988年 | 744篇 |
1987年 | 734篇 |
1986年 | 659篇 |
1985年 | 725篇 |
1984年 | 733篇 |
1983年 | 665篇 |
1982年 | 822篇 |
1981年 | 709篇 |
1980年 | 611篇 |
1979年 | 486篇 |
1978年 | 429篇 |
1977年 | 419篇 |
1976年 | 387篇 |
1974年 | 374篇 |
1973年 | 378篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
Geneticists have, for years, understood the nature of genome‐wide association studies using common genomic variants. Recently, however, focus has shifted to the analysis of rare variants. This presents potential problems for researchers, as rare variants do not always behave in the same way common variants do, sometimes rendering decades of solid intuition moot. In this paper, we present examples of the differences between common and rare variants. We show why one must be significantly more careful about the origin of rare variants, and how failing to do so can lead to highly inflated type I error. We then explain how to best avoid such concerns with careful understanding and study design. Additionally, we demonstrate that a seemingly low error rate in next‐generation sequencing can dramatically impact the false‐positive rate for rare variants. This is due to the fact that rare variants are, by definition, seen infrequently, making it hard to distinguish between errors and real variants. Compounding this problem is the fact that the proportion of errors is likely to get worse, not better, with increasing sample size. One cannot simply scale their way up in order to solve this problem. Understanding these potential pitfalls is a key step in successfully identifying true associations between rare variants and diseases. 相似文献
7.
8.
David M. Presby Michael C. Rudolph Vanessa D. Sherk Matthew R. Jackman Rebecca M. Foright Kenneth L. Jones Julie A. Houck Ginger C. Johnson Janine A. Higgins P. Darrell Neufer Robert H. Eckel Paul S. MacLean 《Diabetes》2021,70(4):867
Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain. 相似文献
9.
10.
If cigarette design was exogenous, inefficiencies arising from smoking could be addressed either with a tax per packet or with an ad valorem tax. However, it is well known that the consequences of these two instruments differ when product characteristics are endogenous. We consider three such characteristics: nicotine, tar, and flavor. Implementation of the first‐best social optimum typically requires the capacity to tax or regulate harmful ingredients. Without such a capacity, the next‐best policy often combines a per‐unit tax on cigarettes with an ad valorem subsidy. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献