全文获取类型
收费全文 | 2896篇 |
免费 | 259篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 90篇 |
妇产科学 | 23篇 |
基础医学 | 391篇 |
口腔科学 | 62篇 |
临床医学 | 311篇 |
内科学 | 742篇 |
皮肤病学 | 33篇 |
神经病学 | 300篇 |
特种医学 | 114篇 |
外科学 | 294篇 |
综合类 | 9篇 |
一般理论 | 3篇 |
预防医学 | 193篇 |
眼科学 | 100篇 |
药学 | 273篇 |
肿瘤学 | 201篇 |
出版年
2024年 | 5篇 |
2023年 | 41篇 |
2022年 | 44篇 |
2021年 | 99篇 |
2020年 | 87篇 |
2019年 | 99篇 |
2018年 | 113篇 |
2017年 | 94篇 |
2016年 | 120篇 |
2015年 | 122篇 |
2014年 | 158篇 |
2013年 | 183篇 |
2012年 | 242篇 |
2011年 | 246篇 |
2010年 | 131篇 |
2009年 | 105篇 |
2008年 | 177篇 |
2007年 | 156篇 |
2006年 | 146篇 |
2005年 | 140篇 |
2004年 | 136篇 |
2003年 | 108篇 |
2002年 | 95篇 |
2001年 | 27篇 |
2000年 | 17篇 |
1999年 | 22篇 |
1998年 | 35篇 |
1997年 | 25篇 |
1996年 | 28篇 |
1995年 | 14篇 |
1994年 | 16篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 12篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 3篇 |
排序方式: 共有3168条查询结果,搜索用时 234 毫秒
991.
BACKGROUND: Intimal thickening is considered to be an early manifestation of developing atherosclerosis in healthy young adults and children. Low birthweight correlates with increased incidence of cardiovascular diseases. AIM: To test the hypothesis that low birthweight is associated with relatively thickened intima at birth. METHODS: The coronary arteries of 175 children were screened from serial cross-sections for maximal intimal thickening and measured morphometrically. The area of intima and media and the length of internal elastic lamina were measured. The intimal to medial area ratio and calculated thicknesses of intima were used in statistical comparisons. Only children who died within 30 d after birth (n=111) were included. RESULTS: There was a significant positive correlation between intimal thickness and birthweight in low-birthweight children (p<0.006). Neither the relative thickness of the intima nor the ratio of intimal to medial area increased with increasing growth restriction. The sum of the thicknesses of arterial media and intima had a significant positive correlation with birthweight in these infants. CONCLUSION: Intimal thickness present at birth in small-for-date children does not seem to be an aetiological factor for the increased risk of coronary heart disease later in life. 相似文献
992.
Neck Vessel Cross‐Sectional Area Measured with MRI: Scan‐Rescan Reproducibility for Longitudinal Evaluations 下载免费PDF全文
Laura Pelizzari Maria Marcella Laganà Dejan Jakimovski Niels Bergsland Jesper Hagemeier Giuseppe Baselli Robert Zivadinov 《Journal of neuroimaging》2018,28(1):48-56
BACKGROUND AND PURPOSE
The cross‐sectional area (CSA) of common carotid arteries‐internal carotid arteries (CCA‐ICAs), vertebral arteries (VAs), and internal jugular veins (IJVs) is influenced by aging. However, the neck vessel CSA can be affected by other factors as well, including subject positioning, hydration, and respiration, especially in longitudinal studies. This study aimed to assess scan‐rescan reproducibility of CCA‐ICAs, VAs, and IJVs CSA measurements in order to evaluate their feasibility for longitudinal CSA assessments, and to apply the segmentation method on a longitudinal pilot dataset.METHODS
Two set of 2‐dimensional neck magnetic resonance angiography (MRA) images were acquired on a 3‐T scanner from two separate datasets: 9 healthy individuals (HIs) were scanned 5 days apart (scan‐rescan dataset) and 12 HIs were acquired 5 years apart (baseline‐follow‐up dataset). CCA‐ICAs, VAs, and IJVs were segmented along the whole vessel length between C3 and C7 intervertebral spaces. Repeated measure analysis of covariance, adjusted for cervical level and sample, and Wilcoxon signed‐rank sum test were used to assess the scan‐rescan and baseline‐follow‐up CSA differences. Intraclass correlation coefficient (ICC) was also computed to evaluate scan‐rescan reliability.RESULTS
No significant CSA differences were found for the scan‐rescan and baseline‐follow‐up CSA comparisons, using the whole vessel length or single cervical level measurements. ICC analysis showed good degree of scan‐rescan reproducibility (considering whole vessel measures: ICC > .9, P‐value < .001 for CCA‐ICAs, ICC > .6, P‐value < .001 for VAs, and ICC > .7, P‐value < .001 for IJVs).CONCLUSIONS
Scan‐rescan reproducibility of CCA‐ICAs, VAs, and IJVs CSA measurements is high, making longitudinal studies feasible. 相似文献993.
994.
Isaac Cano Magí Lluch-Ariet David Gomez-Cabrero Dieter Maier Susana Kalko Marta Cascante Jesper Tegnér Felip Miralles Diego Herrera Josep Roca Synergy-COPD consortium 《Journal of translational medicine》2014,12(Z2):S10
This article describes a Digital Health Framework (DHF), benefitting from the lessons learnt during the three-year life span of the FP7 Synergy-COPD project. The DHF aims to embrace the emerging requirements - data and tools - of applying systems medicine into healthcare with a three-tier strategy articulating formal healthcare, informal care and biomedical research. Accordingly, it has been constructed based on three key building blocks, namely, novel integrated care services with the support of information and communication technologies, a personal health folder (PHF) and a biomedical research environment (DHF-research). Details on the functional requirements and necessary components of the DHF-research are extensively presented. Finally, the specifics of the building blocks strategy for deployment of the DHF, as well as the steps toward adoption are analyzed. The proposed architectural solutions and implementation steps constitute a pivotal strategy to foster and enable 4P medicine (Predictive, Preventive, Personalized and Participatory) in practice and should provide a head start to any community and institution currently considering to implement a biomedical research platform. 相似文献
995.
Dorte L. Nielsen Iben Kümler Jesper A.E. Palshof Michael Andersson 《Breast (Edinburgh, Scotland)》2013,22(1):1-12
Therapies targeting the human epidermal growth factor receptor (HER) 2 are effective in metastatic breast cancer (MBC).We review the efficacy of HER2-directed therapies, focussing on monoclonal antibodies and tyrosine kinase inhibitors targeting HER2 that have been tested in phase II–III studies in MBC.Trastuzumab is an important component of first-line treatment of HER2-positive MBC. New anti-HER2 drugs have the potential to change clinical practice. The potential role of the different drugs and regimens is yet to be determined. The response rate for trastuzumab-DM1 of 26–64% is comparable to those obtained for capecitabine plus lapatinib (48%), continuing trastuzumab in combination with capecitabine (48%), pertuzumab plus trastuzumab (24%), and neratinib (24%). Strategies combining multiple HER2-directed therapies might yield additive or synergistic effects and lead to improved outcome.The future challenges include understanding HER2 functions, designing rational combinations and optimal selection of patients. 相似文献
996.
Anders Kasper Bruun Kristensen Jon Gitz Holler S?ren Mikkelsen Jesper Hallas Annmarie Lassen 《Critical care (London, England)》2015,19(1)
IntroductionSystolic blood pressure is a widely used tool to assess circulatory function in acutely ill patients. The systolic blood pressure limit where a given patient should be considered hypotensive is the subject of debate and recent studies have advocated higher systolic blood pressure thresholds than the traditional 90 mmHg. The aim of this study was to identify the best performing systolic blood pressure thresholds with regards to predicting 7-day mortality and to evaluate the applicability of these in the emergency department as well as in the prehospital setting.MethodsA retrospective, hospital-based cohort study was performed at Odense University Hospital that included all adult patients in the emergency department between 1995 and 2011, all patients transported to the emergency department in ambulances in the period 2012 to 2013, and all patients serviced by the physician-staffed mobile emergency care unit (MECU) in Odense between 2007 and 2013. We used the first recorded systolic blood pressure and the main outcome was 7-day mortality. Best performing thresholds were identified with methods based on receiver operating characteristics (ROC) and multivariate regression. The performance of systolic blood pressure thresholds was evaluated with standard summary statistics for diagnostic tests.ResultsSeven-day mortality rates varied from 1.8 % (95 % CI (1.7, 1.9)) of 112,727 patients in the emergency department to 2.2 % (95 % CI (2.0, 2.5)) of 15,862 patients in the ambulance and 5.7 % (95 % CI (5.3, 6.2)) of 12,270 patients in the mobile emergency care units. Best performing thresholds ranged from 95 to 119 mmHg in the emergency department, 103 to 120 mmHg in the ambulance, and 101 to 115 mmHg in the MECU but area under the ROC curve indicated poor overall discriminatory performance of SBP thresholds in all cohorts.ConclusionsSystolic blood pressure alone is not sufficient to identify patients at risk regardless of the defined threshold for hypotension. If, however, a threshold is to be defined, a systolic blood pressure threshold of 100 to 110 mmHg is probably more relevant than the traditional 90 mmHg.
Electronic supplementary material
The online version of this article (doi:10.1186/s13054-015-0884-y) contains supplementary material, which is available to authorized users. 相似文献997.
998.
Isolation and characterization of 55 novel microsatellite markers for the pink-footed goose (Anser brachyrhynchus) 总被引:1,自引:0,他引:1
Kristina Noreikiene Amber G. F. Teacher Jesper Madsen Phillip Gienapp 《Conservation Genetics Resources》2012,4(2):423-428
Here we present 55 new microsatellite markers isolated from the pink-footed goose (Anser brachyrhynchus), using next generation sequencing. Of these, 44 markers were found to be polymorphic, and the number of alleles ranged from two to ten with a mean of 4.23 alleles per locus. Mean observed heterozygosity was 0.44, and 33 polymorphic markers were in Hardy?CWeinberg equilibrium in our sample population. These newly developed molecular markers could prove to be a useful tool for further studies of pink-footed goose populations. 相似文献
999.
Smoldering multiple myeloma risk factors for progression: a Danish population‐based cohort study 下载免费PDF全文
Rasmus Sørrig Tobias W. Klausen Morten Salomo Annette J. Vangsted Brian Østergaard Henrik Gregersen Ulf Christian Frølund Niels F. Andersen Carsten Helleberg Kristian T. Andersen Robert S. Pedersen Per Pedersen Niels Abildgaard Peter Gimsing the Danish Myeloma Study Group 《European journal of haematology》2016,97(3):303-309
Several risk scores for disease progression in patients with smoldering multiple myeloma (SMM) have been proposed; however, all have been developed using single‐center registries. To examine risk factors for time to progression (TTP) to multiple myeloma (MM) for SMM, we analyzed a nationwide population‐based cohort of 321 patients with newly diagnosed SMM registered within the Danish Multiple Myeloma Registry between 2005 and 2014. Significant univariable risk factors for TTP were selected for multivariable Cox regression analyses. We found that both an M‐protein ≥30 g/L and immunoparesis significantly influenced TTP (HR 2.7, 95%CI (1.5;4.7), P = 0.001, and HR 3.3, 95%CI (1.4;7.8), P = 0.002, respectively). High free light chain (FLC) ratio did not significantly influence TTP in our cohort. Therefore, our data do not support recent IMWG proposal of identifying patients with FLC ratio above 100 as having ultra high‐risk of transformation to MM. Using only immunoparesis and M‐protein ≥30 g/L, we created a scoring system to identify low‐, intermediate‐, and high‐risk SMM. This first population‐based study of patients with SMM confirms that an M‐protein ≥30 g/L and immunoparesis remain important risk factors for progression to MM. 相似文献
1000.