全文获取类型
收费全文 | 5349篇 |
免费 | 406篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 194篇 |
妇产科学 | 187篇 |
基础医学 | 628篇 |
口腔科学 | 45篇 |
临床医学 | 921篇 |
内科学 | 1117篇 |
皮肤病学 | 77篇 |
神经病学 | 439篇 |
特种医学 | 98篇 |
外科学 | 445篇 |
综合类 | 49篇 |
一般理论 | 7篇 |
预防医学 | 678篇 |
眼科学 | 94篇 |
药学 | 370篇 |
中国医学 | 8篇 |
肿瘤学 | 388篇 |
出版年
2024年 | 6篇 |
2023年 | 46篇 |
2022年 | 87篇 |
2021年 | 167篇 |
2020年 | 119篇 |
2019年 | 165篇 |
2018年 | 163篇 |
2017年 | 133篇 |
2016年 | 143篇 |
2015年 | 143篇 |
2014年 | 194篇 |
2013年 | 304篇 |
2012年 | 435篇 |
2011年 | 424篇 |
2010年 | 238篇 |
2009年 | 196篇 |
2008年 | 402篇 |
2007年 | 392篇 |
2006年 | 377篇 |
2005年 | 362篇 |
2004年 | 349篇 |
2003年 | 315篇 |
2002年 | 265篇 |
2001年 | 30篇 |
2000年 | 21篇 |
1999年 | 34篇 |
1998年 | 60篇 |
1997年 | 29篇 |
1996年 | 30篇 |
1995年 | 35篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有5777条查询结果,搜索用时 31 毫秒
991.
992.
Roy CN 《Clinics in Geriatric Medicine》2011,27(1):67-78
Although anemia is regarded as a relatively common occurrence in older adults, the vigor with which the medical community should intervene to correct this common problem is disputed. Epidemiologic data clearly correlate anemia with functional decline, disability, and mortality. Anemia may contribute to functional decline by restricting oxygen delivery to muscle, or to cognitive decline by restricting oxygen delivery to the brain. On the other hand, the erythron may be a separate target of the same biologic mediators that influence deterioration of physiologic systems that contribute to weakness, functional and cognitive decline, and mortality. Clinical trials aimed at treating anemia in older adults could assess whether physical performance is improved or whether mortality risk declines with improved hemoglobin, but sufficient evidence from such trials is currently lacking. With few guidelines regarding treatment of older adults and significant risk for adverse events associated with transfusion and erythroid stimulating agents, anemia often goes untreated or ignored in geriatric clinics. This article reviews the problem of anemia in older adults, with a particular emphasis on the frail elderly. The gaps in the evidence base for the treatment of anemia in older adults are reviewed and the options for advancing the field are assessed. 相似文献
993.
994.
Our aim was to cross-validate electrocardiographic (ECG) and scintigraphic imaging of acute myocardial ischemia. The former method was based on inverse calculation of heart-surface potentials from the body-surface ECGs, and the latter, on a single photon emission computed tomography (SPECT). A boundary-element torso model with 352 body-surface and 202 heart-surface nodes was used to perform the ECG inverse solution. Potentials at 352 body-surface nodes were calculated from those acquired at 12-lead ECG measurement sites using regression coefficients developed from a design set (n = 892) of body-surface potential mapping (BSPM) data. The test set (n = 18) consisted of BSPM data from patients who underwent a balloon-inflation angioplasty of either the left anterior descending coronary artery (LAD) (n = 7), left circumflex coronary artery (LCx) (n = 2), or the right coronary artery (RCA) (n = 9). Body-surface potential mapping distributions at J point for 352 nodes were estimated from the 12-lead ECG, and an agreement with those estimated from 120 leads was assessed by a correlation coefficient (CC) (in percent). These estimates yielded very similar BSPM distributions, with a CC of 91.0% ± 8.1% (mean ± SD) for the entire test set and 94.1% ± 1.4%, 96.7% ± 0.8%, and 87.4% ± 10.3% for LAD, LCx, and RCA subgroups, respectively. Corresponding heart-surface potential distributions obtained by inverse solution correlated with a lower CC of 69.3% ± 18.0% overall and 73.7% ± 10.8%, 84.7% ± 1.1%, and 62.6% ± 21.8%, respectively, for subgroups. Bull's-eye displays of heart-surface potentials calculated from estimated BSPM distributions had an area of positive potentials that qualitatively corresponded, in general, with the underperfused territory suggested by SPECT images. For the LAD and LCx groups, all 9 ECG-derived bull's-eye images indicated the expected territory; for the RCA group, 6 of 9 ECG-derived images were as expected; 2 of 3 misclassified cases had very small ECG changes in response to coronary-artery occlusion, and their SPECT images showed indiscernible patterns. In conclusion, our findings demonstrate that noninvasive ECG imaging based on just the 12-lead ECG might provide useful estimates of the regions of myocardial ischemia that agree with those provided by scintigraphic techniques. 相似文献
995.
996.
997.
998.
Objective. The purpose of this study was to compare perceived parenting abilities in mothers with systemic sclerosis (SSc) based on the subtype of SSc and age group of their children, and to examine how the degree of pain, fatigue and functional ability relates to parenting ability. Methods. In this cross‐sectional survey, 74 mothers with SSc, who had children aged 18 years or younger living at home with them, completed a series of questionnaires online or on paper. The questionnaires included the Parent Disability Index (PDI) and surveys regarding demographic information, pain (visual analogue scale), fatigue (Multidimensional Assessment of Fatigue) and functional ability (Health Assessment Questionnaire). Results. An analysis of variance revealed that the mean age of the mother (F2,71 = 7.9; p < 0.01), mean PDI score (F2,68 = 5.4; p < 0.01) and mean pain score (F2,71 = 4.0; p = 0.02) were each associated with the age group of the children. The univariate analysis of variance results showed that dichotomized pain (F1,69 = 13.3; p < 0.01), fatigue (F1,69 = 18.9; p < 0.01) and disability (F1,69 = 9.8; p < 0.01) were each associated with the PDI score. The multivariate analysis of variance results showed that dichotomized pain (F1,68 = 7.5; p < 0.01) and fatigue (F1,68 = 12.7; p < 0.01) were associated with the PDI. Conclusion. Mothers with SSc report difficulty with parenting, which can be related to the severity of the symptoms. The findings suggest that interventions to reduce pain and fatigue may improve perceived parenting ability. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
999.
The left atrial appendage (LAA) is the primary nonvalvular cause of cardioembolic stroke in patients with atrial fibrillation
(AF). Warfarin and direct thrombin inhibitors such as dabigatran are presumed to prevent formation of LAA thrombus, and are
first-line treatments to prevent ischemic stroke in AF. However, these medications carry many contraindications such as hemorrhage,
and can interact with many drugs and supplements. Epicardial and endovascular techniques for occlusion of LAA are being explored,
whether to mitigate the need for anticoagulation in patients at risk of bleeding or as a first-line therapy to reduce the
risk of thromboembolic stroke. The purposes of this article are to 1) review the LAA structure and its potential contribution
to ischemic stroke; 2) discuss the results of surgical and endovascular trials of LAA occlusion on risk of stroke and adverse
events in AF patients; and 3) present early data on devices in development. 相似文献
1000.
Hobson-Peters J Arévalo C Cheah WY Blitvich BJ Tan CS Sandis A Araya LN Hernández JL Toye P Hall RA 《Vector borne and zoonotic diseases (Larchmont, N.Y.)》2011,11(8):1081-1084
We conducted a serosurvey for West Nile virus (WNV) infection in equines in Costa Rica in 2004. Antibodies to WNV were detected in 28% of the horses using an epitope blocking ELISA that is specific for WNV. WNV infection was confirmed for a subset of these sera by plaque reduction neutralization tests and Western blot. This is the first evidence of WNV activity in Costa Rica. 相似文献