收费全文 | 14115篇 |
免费 | 1314篇 |
国内免费 | 59篇 |
耳鼻咽喉 | 168篇 |
儿科学 | 467篇 |
妇产科学 | 423篇 |
基础医学 | 1943篇 |
口腔科学 | 252篇 |
临床医学 | 1926篇 |
内科学 | 2581篇 |
皮肤病学 | 237篇 |
神经病学 | 1400篇 |
特种医学 | 583篇 |
外国民族医学 | 1篇 |
外科学 | 1636篇 |
综合类 | 281篇 |
一般理论 | 12篇 |
预防医学 | 1480篇 |
眼科学 | 333篇 |
药学 | 912篇 |
中国医学 | 19篇 |
肿瘤学 | 834篇 |
2022年 | 109篇 |
2021年 | 242篇 |
2020年 | 170篇 |
2019年 | 227篇 |
2018年 | 320篇 |
2017年 | 239篇 |
2016年 | 250篇 |
2015年 | 262篇 |
2014年 | 394篇 |
2013年 | 580篇 |
2012年 | 725篇 |
2011年 | 691篇 |
2010年 | 416篇 |
2009年 | 401篇 |
2008年 | 623篇 |
2007年 | 622篇 |
2006年 | 648篇 |
2005年 | 660篇 |
2004年 | 552篇 |
2003年 | 511篇 |
2002年 | 502篇 |
2001年 | 354篇 |
2000年 | 341篇 |
1999年 | 330篇 |
1998年 | 181篇 |
1997年 | 169篇 |
1996年 | 148篇 |
1995年 | 139篇 |
1994年 | 149篇 |
1993年 | 121篇 |
1992年 | 259篇 |
1991年 | 257篇 |
1990年 | 243篇 |
1989年 | 221篇 |
1988年 | 270篇 |
1987年 | 238篇 |
1986年 | 241篇 |
1985年 | 223篇 |
1984年 | 176篇 |
1983年 | 170篇 |
1982年 | 124篇 |
1981年 | 128篇 |
1980年 | 105篇 |
1979年 | 184篇 |
1978年 | 134篇 |
1977年 | 103篇 |
1976年 | 130篇 |
1975年 | 120篇 |
1974年 | 128篇 |
1973年 | 94篇 |
![点击此处可从《Neuromodulation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Introduction
Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.Methods
Incident dementia diagnoses from 1/1/2010 to 9/30/2015 were abstracted from medical records for 2350 members of an integrated health care system in California (n = 1702 whites, n = 375 blacks, n = 105 Latinos, n = 168 Asians) aged ≥90 in 2010. We estimated race/ethnicity-specific age-adjusted dementia incidence rates and implemented Cox proportional hazards models and Fine and Gray competing risk of death models adjusted for demographics and comorbidities in midlife and late-life.Results
Dementia incidence rates (n = 771 cases) were lowest among Asians (89.9/1000 person-years), followed by whites (96.9/1000 person-years), Latinos (105.8/1000 person-years), and blacks (121.5/1000 person-years). Cox regression and competing risk models estimated 28% and 36% higher dementia risk for blacks versus whites adjusting for demographics and comorbidities.Discussion
Patterns of racial/ethnic disparities in dementia seen in younger older adults continue after the age of 90 years, though smaller in magnitude. 相似文献Objective: To quantify spatiotemporal and kinematic BW characteristics in post-stroke community ambulators and compare their performance to controls.
Methods: Individuals post-stroke (n = 15, 60.1 ± 12.9 years, forward speed: 1.13 ± 0.23 m/s) and healthy adults (n = 12, 61.2 ± 16.2 years, forward speed: 1.40 ± 0.13 m/s) performed forward walking (FW) and BW during a single session. Step characteristics and peak lower extremity joint angles were extracted using 3D motion analysis and analyzed with mixed-method ANOVAs (group, walking condition).
Results: The stroke group demonstrated greater reductions in speed, step length and cadence and a greater increase in double-support time during BW compared to FW (p < .01). Compared to FW, the post-stroke group demonstrated greater reductions in hip extension and knee flexion during BW (p < .05). The control group demonstrated decreased plantarflexion and increased dorsiflexion during BW, but these increases were attenuated in the post-stroke group (p < .05).
Conclusions: Assessment of BW can unmask post-stroke walking impairments not detected during typical FW. BW impairments may contribute to the mobility difficulties reported by adults post-stroke. Therefore, BW should be assessed when determining readiness for home and community ambulation. 相似文献