全文获取类型
收费全文 | 8573篇 |
免费 | 745篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 210篇 |
妇产科学 | 126篇 |
基础医学 | 1065篇 |
口腔科学 | 321篇 |
临床医学 | 964篇 |
内科学 | 1994篇 |
皮肤病学 | 78篇 |
神经病学 | 640篇 |
特种医学 | 272篇 |
外科学 | 1189篇 |
综合类 | 120篇 |
一般理论 | 5篇 |
预防医学 | 926篇 |
眼科学 | 153篇 |
药学 | 739篇 |
中国医学 | 14篇 |
肿瘤学 | 470篇 |
出版年
2022年 | 71篇 |
2021年 | 171篇 |
2020年 | 82篇 |
2019年 | 158篇 |
2018年 | 197篇 |
2017年 | 150篇 |
2016年 | 153篇 |
2015年 | 174篇 |
2014年 | 244篇 |
2013年 | 366篇 |
2012年 | 553篇 |
2011年 | 534篇 |
2010年 | 286篇 |
2009年 | 280篇 |
2008年 | 463篇 |
2007年 | 484篇 |
2006年 | 468篇 |
2005年 | 458篇 |
2004年 | 456篇 |
2003年 | 354篇 |
2002年 | 424篇 |
2001年 | 156篇 |
2000年 | 152篇 |
1999年 | 180篇 |
1998年 | 78篇 |
1997年 | 90篇 |
1996年 | 68篇 |
1995年 | 68篇 |
1994年 | 62篇 |
1993年 | 49篇 |
1992年 | 116篇 |
1991年 | 108篇 |
1990年 | 101篇 |
1989年 | 109篇 |
1988年 | 98篇 |
1987年 | 93篇 |
1986年 | 93篇 |
1985年 | 89篇 |
1984年 | 86篇 |
1983年 | 82篇 |
1982年 | 81篇 |
1981年 | 71篇 |
1980年 | 46篇 |
1979年 | 70篇 |
1978年 | 47篇 |
1977年 | 47篇 |
1976年 | 49篇 |
1974年 | 49篇 |
1973年 | 32篇 |
1972年 | 39篇 |
排序方式: 共有9328条查询结果,搜索用时 15 毫秒
191.
192.
193.
194.
Kevin Messacar Christine C. Robinson Dayanand Bagdure Donna J. Curtis Mary P. Glodé Samuel R. Dominguez 《Journal of clinical virology》2013,56(1):41-45
BackgroundThe relative impact of human rhino/enteroviruses (HRV/EV) compared to influenza viruses on hospitalized children is unknown.ObjectivesThis retrospective study compared the epidemiology and clinical characteristics of hospitalized patients with HRV/EV to patients hospitalized with influenza virus.Study designRespiratory specimens from hospitalized children submitted between January 1, 2009 and December 31, 2009 to Children's Hospital Colorado Virology Laboratory in Aurora, CO were tested by a commercial multiplex PCR for 16 respiratory viruses and subtypes. Patients with specimens positive for HRV/EV or influenza virus without bacterial or viral co-infection were selected for retrospective chart review.ResultsOf the 2299 patients with specimens tested during the study period, 427 (18.6%) were singly positive for HRV/EV and 202 (8.8%) for influenza virus (p < 0.01). Children with HRV/EV were more likely to present with increased work of breathing (67.9% vs. 52.5%, p < 0.01) with crackles (36.3% vs. 23.3%, p < 0.01) and wheezing (41.7% vs. 22.8%, p < 0.01) noted on exam. Children hospitalized with HRV/EV had a shorter median length of stay (2 days vs. 3 days, p < 0.01), duration of fever (1 days vs. 3 days, p < 0.01), and duration of hypoxemia (2 days vs. 3 days, p < 0.01) than children with influenza virus. Similar percentages of children with HRV/EV and influenza virus were admitted to the PICU and required positive pressure ventilation. There were no deaths in children hospitalized with HRV/EV, whereas 6 children with influenza virus expired.ConclusionsHRV/EVs are common pathogens in hospitalized children associated with serious lower respiratory tract disease and significant morbidity, similar to influenza viruses. 相似文献
195.
196.
197.
Robert L. Hanson Rong Rong Sayuko Kobes Yunhua Li Muller E. Jennifer Weil Jeffrey M. Curtis Robert G. Nelson Leslie J. Baier 《Diabetes》2015,64(7):2646-2657
Several single nucleotide polymorphisms (SNPs) associated with type 2 diabetes mellitus (T2DM) have been identified, but there is little information on their role in populations at high risk for T2DM. We genotyped SNPs at 63 T2DM loci in 3,421 individuals from a high-risk American Indian population. Nominally significant (P < 0.05) associations were observed at nine SNPs in a direction consistent with the established association. A genetic risk score derived from all loci was strongly associated with T2DM (odds ratio 1.05 per risk allele, P = 6.2 × 10−6) and, in 292 nondiabetic individuals, with lower insulin secretion (by 4% per copy, P = 4.1 × 10−6). Genetic distances between American Indians and HapMap populations at T2DM markers did not differ significantly from genomic expectations. Analysis of U.S. national survey data suggested that 66% of the difference in T2DM prevalence between African Americans and European Americans, but none of the difference between American Indians and European Americans, was attributable to allele frequency differences at these loci. These analyses suggest that, in general, established T2DM loci influence T2DM in American Indians and that risk is mediated in part through an effect on insulin secretion. However, differences in allele frequencies do not account for the high population prevalence of T2DM. 相似文献
198.
Wrist Fracture and Risk of Subsequent Fracture: Findings from the Women's Health Initiative Study
下载免费PDF全文
![点击此处可从《Journal of bone and mineral research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Carolyn J Crandall Kathleen M Hovey Jane A Cauley Christopher A Andrews Jeffrey R Curtis Jean Wactawski‐Wende Nicole C Wright Wenjun Li Meryl S LeBoff 《Journal of bone and mineral research》2015,30(11):2086-2095
Wrist fractures are common in postmenopausal women and are associated with functional decline. Fracture patterns after wrist fracture are unclear. The goal of this study was to determine the frequency and types of fractures that occur after a wrist fracture among postmenopausal women. We carried out a post hoc analysis of data from the Women's Health Initiative Observational Study and Clinical Trials (1993–2010) carried out at 40 US clinical centers. Participants were postmenopausal women aged 50 to 79 years at baseline. Mean follow‐up duration was 11.8 years. Main measures included incident wrist, clinical spine, humerus, upper extremity, lower extremity, hip, and total non‐wrist fractures and bone mineral density (BMD) in a subset. Among women who experienced wrist fracture, 15.5% subsequently experienced non‐wrist fracture. The hazard for non‐wrist fractures was higher among women who had experienced previous wrist fracture than among women who had not experienced wrist fracture: non‐wrist fracture overall (hazard ratio [HR] = 1.40, 95% confidence interval [CI] 1.33–1.48), spine (HR = 1.48, 95% CI 1.32–1.66), humerus (HR = 1.78, 95% CI 1.57–2.02), upper extremity (non‐wrist) (HR = 1.88, 95% CI 1.70–2.07), lower extremity (non‐hip) (HR = 1.36, 95% CI 1.26–1.48), and hip (HR = 1.50, 95% CI 1.32–1.71) fracture. Associations persisted after adjustment for BMD, physical activity, and other risk factors. Risk of non‐wrist fracture was higher in women who were younger when they experienced wrist fracture (interaction p value 0.02). Associations between incident wrist fracture and subsequent non‐wrist fracture did not vary by baseline BMD category (normal, low bone density, osteoporosis). A wrist fracture is associated with increased risk of subsequent hip, vertebral, upper extremity, and lower extremity fractures. There may be substantial missed opportunity for intervention in the large number of women who present with wrist fractures. © 2015 American Society for Bone and Mineral Research. 相似文献
199.
OBJECTIVE: Little is known about the impact of fellowship training in primary care on subsequent research productivity. Our goal was to identify characteristics of research fellows and their training associated with subsequent publications and research funding. DESIGN: Mail survey in 1998. SETTING AND PARTICIPANTS: 1988-1997 graduates of 25 National Research Service Award primary care research fellowships in the United States. OUTCOME MEASURES: 1) Publishing 1 or more papers per year since the beginning of fellowship, or 2) serving as principal investigator (PI) on a federal or non-federal grant. RESULTS: One hundred forty-six of two hundred fifteen program graduates (68%) completed the survey. The median age was 38 years, and 51% were male. Thirty-two percent had published 1 or more papers per year, and 44% were PIs. Male gender (odds ratio [OR], 3.6; 95% confidence interval [95% CI], 1.4 to 9.2), self-reported allocation of 40% or more of fellowship time to research (OR, 4.4; 95% CI, 1.8 to 11.2), and having an influential mentor during fellowship (OR, 5.0; 95% CI, 1.5 to 17.2) were independently associated with publishing 1 or more papers per year. Fellows with funding as a PI were also more likely to have an influential mentor (OR, 3.0; 95% CI, 1.3 to 7.2). CONCLUSION: Primary care fellows who had influential mentors were more productive in research early after fellowship. Awareness of the indicators of early research success can inform the policies of agencies that fund research training and the curricula of training programs themselves. 相似文献
200.