全文获取类型
收费全文 | 1514291篇 |
免费 | 120763篇 |
国内免费 | 3689篇 |
专业分类
耳鼻咽喉 | 19747篇 |
儿科学 | 49247篇 |
妇产科学 | 42802篇 |
基础医学 | 214132篇 |
口腔科学 | 39779篇 |
临床医学 | 136544篇 |
内科学 | 305542篇 |
皮肤病学 | 34981篇 |
神经病学 | 126898篇 |
特种医学 | 57295篇 |
外国民族医学 | 468篇 |
外科学 | 225514篇 |
综合类 | 34500篇 |
现状与发展 | 4篇 |
一般理论 | 648篇 |
预防医学 | 119746篇 |
眼科学 | 34010篇 |
药学 | 105818篇 |
3篇 | |
中国医学 | 3500篇 |
肿瘤学 | 87565篇 |
出版年
2021年 | 12503篇 |
2019年 | 13313篇 |
2018年 | 18461篇 |
2017年 | 14142篇 |
2016年 | 15877篇 |
2015年 | 17982篇 |
2014年 | 25408篇 |
2013年 | 37826篇 |
2012年 | 51732篇 |
2011年 | 54785篇 |
2010年 | 32066篇 |
2009年 | 30844篇 |
2008年 | 50972篇 |
2007年 | 53874篇 |
2006年 | 54441篇 |
2005年 | 53075篇 |
2004年 | 50687篇 |
2003年 | 48467篇 |
2002年 | 46588篇 |
2001年 | 73985篇 |
2000年 | 75274篇 |
1999年 | 62578篇 |
1998年 | 18430篇 |
1997年 | 16612篇 |
1996年 | 16525篇 |
1995年 | 15718篇 |
1994年 | 14174篇 |
1993年 | 13381篇 |
1992年 | 46459篇 |
1991年 | 44035篇 |
1990年 | 42028篇 |
1989年 | 40078篇 |
1988年 | 36647篇 |
1987年 | 35800篇 |
1986年 | 33314篇 |
1985年 | 31845篇 |
1984年 | 24503篇 |
1983年 | 20718篇 |
1982年 | 13173篇 |
1981年 | 11666篇 |
1979年 | 21097篇 |
1978年 | 15067篇 |
1977年 | 12544篇 |
1976年 | 11743篇 |
1975年 | 11965篇 |
1974年 | 14280篇 |
1973年 | 13799篇 |
1972年 | 12818篇 |
1971年 | 11586篇 |
1970年 | 11034篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
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
72.
73.
74.
75.
76.
77.
Michael E Egger Joanna M Ohlendorf Charles R Scoggins Kelly M McMasters Robert C G Martin II 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2015,17(9):839-845
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery. 相似文献
78.
79.
80.