全文获取类型
| 收费全文 | 326761篇 |
| 免费 | 23485篇 |
| 国内免费 | 1239篇 |
专业分类
| 耳鼻咽喉 | 3560篇 |
| 儿科学 | 9010篇 |
| 妇产科学 | 6356篇 |
| 基础医学 | 42793篇 |
| 口腔科学 | 6724篇 |
| 临床医学 | 31660篇 |
| 内科学 | 69136篇 |
| 皮肤病学 | 4216篇 |
| 神经病学 | 31692篇 |
| 特种医学 | 10593篇 |
| 外国民族医学 | 15篇 |
| 外科学 | 49503篇 |
| 综合类 | 4962篇 |
| 现状与发展 | 3篇 |
| 一般理论 | 441篇 |
| 预防医学 | 29327篇 |
| 眼科学 | 7553篇 |
| 药学 | 22817篇 |
| 2篇 | |
| 中国医学 | 639篇 |
| 肿瘤学 | 20483篇 |
出版年
| 2023年 | 1291篇 |
| 2022年 | 2008篇 |
| 2021年 | 5730篇 |
| 2020年 | 3494篇 |
| 2019年 | 5718篇 |
| 2018年 | 6685篇 |
| 2017年 | 5179篇 |
| 2016年 | 5748篇 |
| 2015年 | 6699篇 |
| 2014年 | 9898篇 |
| 2013年 | 14219篇 |
| 2012年 | 21126篇 |
| 2011年 | 22906篇 |
| 2010年 | 12791篇 |
| 2009年 | 11734篇 |
| 2008年 | 21240篇 |
| 2007年 | 22470篇 |
| 2006年 | 21569篇 |
| 2005年 | 22000篇 |
| 2004年 | 21015篇 |
| 2003年 | 19519篇 |
| 2002年 | 18842篇 |
| 2001年 | 3077篇 |
| 2000年 | 2363篇 |
| 1999年 | 3258篇 |
| 1998年 | 4203篇 |
| 1997年 | 3592篇 |
| 1996年 | 3082篇 |
| 1995年 | 2846篇 |
| 1994年 | 2518篇 |
| 1993年 | 2409篇 |
| 1992年 | 1874篇 |
| 1991年 | 1745篇 |
| 1990年 | 1595篇 |
| 1989年 | 1464篇 |
| 1988年 | 1508篇 |
| 1987年 | 1495篇 |
| 1986年 | 1400篇 |
| 1985年 | 1578篇 |
| 1984年 | 2027篇 |
| 1983年 | 1952篇 |
| 1982年 | 2467篇 |
| 1981年 | 2212篇 |
| 1980年 | 2049篇 |
| 1979年 | 1183篇 |
| 1978年 | 1291篇 |
| 1977年 | 1257篇 |
| 1976年 | 1113篇 |
| 1975年 | 950篇 |
| 1974年 | 939篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
81.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献82.
Stephanie A. Grilo Marina Catallozzi John S. Santelli Hanying Yan Xiaoyu Song Jennifer Heitel Kristen Kaseeska Julie Gorzkowski Alexandra E. Dereix Jonathan D. Klein 《The Journal of adolescent health》2019,64(3):311-318
Purpose
The objective of the study was to define factors associated with adolescent and young adult (AYA) experiences with private time and having discussed confidentiality and the impact of these experiences on improving delivery of clinical preventive services.Methods
In 2016, a nationally representative sample of 1,918 US AYAs (13- to 26-year-olds) was surveyed. Survey questionnaire domains were based on prior research and Fishers' information-motivation-behavior skills conceptual model. Data were weighted to represent US households with AYA and analyzed to identify factors independently associated with ever experiencing private time and discussions of confidentiality with a regular health-care provider (HCP). We examined the association of these experiences on AYA attitudes about health care.Results
Fifty-five percent of female and 49% of male AYA reported ever having had private time with an HCP and 55% of female and 44% of male AYA had spoken to an HCP about confidentiality. Independent predictors of having experienced private time and confidentiality included older age, race, higher household income, gender of the provider, amount of years with the provider, and involvement in risk behaviors. AYA who had experienced private time and confidentiality discussions had more positive attitudes about their providers, were more willing and comfortable discussing sensitive topics, and thought that these discussions should happen at younger ages.Conclusions
Although confidentiality and private time are important to AYA, many are not experiencing these components of care. Providing private time and discussions of confidentiality can improve the delivery of health care for young people by enhancing positive youth attitudes about preventive care. 相似文献83.
J. John Mann Allison V. Metts R. Todd Ogden Chester A. Mathis Harry Rubin-Falcone Zhiqun Gong 《Archives of Suicide Research》2019,23(1):122-133
Objective: To determine serotonin system abnormalities related to major depression or previous suicidal behavior.
Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.
Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.
Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents. 相似文献
84.
Algorithms based on deep neural networks (DNNs) have attracted increasing attention from the scientific computing community. DNN based algorithms are
easy to implement, natural for nonlinear problems, and have shown great potential to
overcome the curse of dimensionality. In this work, we utilize the multi-scale DNN-based algorithm (MscaleDNN) proposed by Liu, Cai and Xu (2020) to solve multi-scale
elliptic problems with possible nonlinearity, for example, the p-Laplacian problem.
We improve the MscaleDNN algorithm by a smooth and localized activation function.
Several numerical examples of multi-scale elliptic problems with separable or non-separable scales in low-dimensional and high-dimensional Euclidean spaces are used
to demonstrate the effectiveness and accuracy of the MscaleDNN numerical scheme. 相似文献
85.
86.
87.
88.
89.
Annals of Surgical Oncology - 相似文献