全文获取类型
收费全文 | 4632篇 |
免费 | 357篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 180篇 |
妇产科学 | 91篇 |
基础医学 | 604篇 |
口腔科学 | 100篇 |
临床医学 | 518篇 |
内科学 | 1098篇 |
皮肤病学 | 51篇 |
神经病学 | 321篇 |
特种医学 | 252篇 |
外科学 | 619篇 |
综合类 | 69篇 |
一般理论 | 3篇 |
预防医学 | 431篇 |
眼科学 | 53篇 |
药学 | 333篇 |
中国医学 | 5篇 |
肿瘤学 | 240篇 |
出版年
2023年 | 29篇 |
2022年 | 22篇 |
2021年 | 71篇 |
2020年 | 41篇 |
2019年 | 78篇 |
2018年 | 78篇 |
2017年 | 71篇 |
2016年 | 77篇 |
2015年 | 74篇 |
2014年 | 94篇 |
2013年 | 191篇 |
2012年 | 265篇 |
2011年 | 266篇 |
2010年 | 165篇 |
2009年 | 160篇 |
2008年 | 256篇 |
2007年 | 279篇 |
2006年 | 274篇 |
2005年 | 273篇 |
2004年 | 209篇 |
2003年 | 205篇 |
2002年 | 207篇 |
2001年 | 133篇 |
2000年 | 132篇 |
1999年 | 103篇 |
1998年 | 47篇 |
1997年 | 47篇 |
1996年 | 56篇 |
1995年 | 32篇 |
1994年 | 35篇 |
1993年 | 49篇 |
1992年 | 73篇 |
1991年 | 71篇 |
1990年 | 93篇 |
1989年 | 62篇 |
1988年 | 54篇 |
1987年 | 54篇 |
1986年 | 46篇 |
1985年 | 48篇 |
1984年 | 30篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 24篇 |
1980年 | 24篇 |
1979年 | 38篇 |
1977年 | 22篇 |
1975年 | 24篇 |
1974年 | 32篇 |
1973年 | 22篇 |
1970年 | 23篇 |
排序方式: 共有4994条查询结果,搜索用时 31 毫秒
151.
Nephrectomy for benign disease in the UK: results from the British Association of Urological Surgeons nephrectomy database 下载免费PDF全文
152.
Daniel Berglind Mikaela Willmer Per Tynelius Ata Ghaderi Erik Näslund Finn Rasmussen 《Obesity surgery》2016,26(7):1463-1470
Background
Roux-en-Y gastric bypass (RYGB) patients report significant pre- to post-surgery increases in physical activity (PA). Conversely, objectively assessed PA does not increase after RYGB. The aim of the study was to compare self-reported and accelerometer-measured changes in moderate-to-vigorous PA (MVPA) and exercise from pre- to post-surgery, in women undergoing RYGB.Methods
Forty-three women with an average pre-surgery body mass index of 39.2 kg/m2 (SD 3.1) were recruited at Swedish hospitals. PA was measured by the Actigraph GT3X+ and by a previously validated short PA questionnaire, at home visits 3 months before and 9 months after surgery, thus limiting seasonal effects.Results
Self-reported time spent in exercise increased with 75 % and time spent in MVPA increased with 51 %, whereas accelerometer-assessed time spent in exercise increased with 0.9 % and time spent in MVPA increased with 2.1 %, from before to after surgery. Correlations comparing accelerometers with the questionnaire were 0.35 (P?=?0.02) for MVPA and 0.13 (P?=?0.4) for exercise before RYGB and 0.52 (P?≤?0.001) for MVPA and 0.12 (P?=?0.4) for exercise after RYGB.Conclusions
Pre- to post-RYGB surgery increases in self-reported PA were not confirmed by accelerometer-measured PA. Thus, health care workers should use objective measures of PA in patients undergoing RYGB, in order to assess whether patients achieve sufficient levels of PA.153.
Protagonistic pleiotropy: Why cancer may be the only pathogenic effect of accumulating nuclear mutations and epimutations in aging 总被引:1,自引:0,他引:1
de Grey AD 《Mechanisms of ageing and development》2007,128(7-8):456-459
Since Szilard's seminal 1959 article, the role of accumulating nuclear DNA (nDNA) damage -- whether as mutations, i.e. changes to sequence, or as epimutations, i.e. adventitious but persistent alterations to methylation and other decorations of nDNA and histones -- has been widely touted as likely to contribute substantially to the aging process throughout the animal kingdom. Such damage certainly accumulates with age and is central to one of the most prevalent age-related causes of death in mammals, namely cancer. However, its role in contributing to the rates of other aspects of aging is less clear. Here I argue that, in animals prone to cancer, evolutionary pressure to postpone cancer will drive the fidelity of nDNA maintenance and repair to a level greatly exceeding that needed to prevent nDNA damage from reaching levels during a normal lifetime that are pathogenic other than via cancer or, possibly, apoptosis resistance. I term this the "protagonistic pleiotropy of chromosomal damage" (PPCD) hypothesis, because this interaction of cancer-related and -unrelated damage is the converse of the well-known "antagonistic pleiotropy" phenomenon. I then consider a selection of recent data on the rate of accumulation of nDNA damage in the context of this hypothesis, and conclude that all presently available evidence is consistent with it. If this conclusion is correct, the implications for the feasibility of greatly postponing mammalian (and eventually human) aging and age-related pathology are far-reaching. 相似文献
154.
155.
156.
157.
Duration of Antiresorptive Effects of Low‐Dose Zoledronate in Osteopenic Postmenopausal Women: A Randomized,Placebo‐Controlled Trial 下载免费PDF全文
Andrew Grey MD Mark Bolland Bobby Mihov Sumwai Wong Anne Horne Greg Gamble Ian R Reid 《Journal of bone and mineral research》2014,29(1):166-172
Annual intravenous administration of 5 mg zoledronate decreases fracture risk, but the optimal dosing regimen for zoledronate has not been determined. We set out to evaluate the antiresorptive effects of a single administration of lower doses of zoledronate. A total of 180 postmenopausal women with osteopenia enrolled in a double‐blind, randomized, placebo‐controlled trial over 2 years at an academic research center. Participants were randomized to a single baseline administration of intravenous zoledronate in doses of 1 mg, 2.5 mg, or 5 mg, or placebo. The primary endpoint was change in bone mineral density(BMD) at the lumbar spine. Secondary endpoints were change in BMD at the proximal femur and total body, and changes in biochemical markers of bone turnover. After 2 years, the change in spine BMD was greater in each of the zoledronate groups than in the placebo group; values are mean (95% confidence interval [CI]) difference versus placebo: zoledronate 1 mg 4.4% [2.7% to 6.1%]; 2.5 mg 5.5% [3.9% to 7.2%]; 5 mg 5.3% [3.8% to 6.7%], p < 0.001 for each dose). Change in BMD at the total hip was greater in each of the zoledronate groups than the placebo group (mean [95% CI] difference versus placebo: zoledronate 1 mg 2.6% [1.5% to 3.7%]; 2.5 mg 4.4% [3.5% to 5.3%]; 5 mg 4.7% [3.7% to 5.7%], p < 0.001 for each dose). Each of the bone turnover markers, β‐C‐terminal telopeptide of type I collagen (β‐CTX) and procollagen type‐I N‐terminal propeptide (P1NP), was lower in each of the 2.5‐mg and 5‐mg zoledronate groups than the placebo group throughout the trial (p < 0.001 versus placebo for each marker for each dose at each time point). For each endpoint, changes were similar in the 2.5‐mg and 5‐mg zoledronate groups, whereas those in the 1‐mg group were smaller than those in the other zoledronate groups. These data demonstrate that single administrations of zoledronate 1 mg or 2.5 mg produce antiresorptive effects that persist for at least 2 years. Trials assessing the antifracture efficacy of intermittent low doses of zoledronate, in particular the 2.5‐mg dose, are justified. © 2014 American Society for Bone and Mineral Research. 相似文献
158.
Devon L. Golem Jennifer T. Martin-Biggers Mallory M. Koenings Katherine Finn Davis Carol Byrd-Bredbenner 《Advances in nutrition (Bethesda, Md.)》2014,5(6):742-759
Sleep is an essential lifestyle factor that contributes to overall health. The inverse relation between sleep duration and weight status has revealed the importance of sleep in nutritional health. This integrative review builds foundational knowledge with regard to sleep vis-à-vis nutrition by summarizing the importance and process of sleep, current sleep recommendations and trends, as well as lifestyle contributors to poor sleep. Additionally, it details the association between sleep and obesity and potential mechanisms for this association. Furthermore, guidance is offered regarding the incorporation of sleep considerations in nutrition counseling, communication, and research. Like many other lifestyle factors that contribute to nutritional health, sleep needs to be considered when examining weight management and health promotion. 相似文献
159.
An infant male presented with the rare anatomy consisting of situs solitus, concordant atrioventricular connections to L-looped ventricles, double outlet right ventricle (DORV), and hypoplastic aortic arch. 6 months after
neonatal aortic arch repair, the morphologic right ventricle function deteriorated, and surgical evaluation was
undertaken to determine if either biventricular repair with a systemic morphologic left ventricle or right ventricular exclusion was possible. After initial echocardiography, magnetic resonance imaging (MRI) was used to create detailed axial and 4-dimensional (4D) images and 3-dimensional (3D) printed models. The detailed anatomy
of this rare, complex case and its use in pre-surgical planning is presented. 相似文献
160.
Ramon Z. Shaban Cecilia Li Matthew V. N. O'Sullivan John Gerrard Rhonda L. Stuart Joanne Teh Nicole Gilroy Tania C. Sorrell Elizabeth White Shopna Bag Kate Hackett Sharon C. A. Chen Jen Kok Dominic E. Dwyer Jonathan R. Iredell Susan Maddocks Patricia Ferguson Kavita Varshney Ian Carter Ruth Barratt Mark Robertson Sai R. Baskar Caren Friend Roselle S. Robosa Cristina Sotomayor‐Castillo Shizar Nahidi Deborough A. Macbeth Kylie A. D. Alcorn Andre Wattiaux Frederick Moore Jamie McMahon William Naughton Tony M. Korman Mike Catton Rupa Kanapathipillai Finn Romanes Emily Rowe Jennifer Catford Brendan Kennedy Ming Qiao David Shaw 《Internal medicine journal》2021,51(1):42-51