全文获取类型
收费全文 | 14885篇 |
免费 | 1230篇 |
国内免费 | 246篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 507篇 |
妇产科学 | 316篇 |
基础医学 | 976篇 |
口腔科学 | 130篇 |
临床医学 | 1491篇 |
内科学 | 3237篇 |
皮肤病学 | 149篇 |
神经病学 | 594篇 |
特种医学 | 234篇 |
外科学 | 1135篇 |
综合类 | 1283篇 |
现状与发展 | 1篇 |
一般理论 | 7篇 |
预防医学 | 4578篇 |
眼科学 | 140篇 |
药学 | 696篇 |
2篇 | |
中国医学 | 168篇 |
肿瘤学 | 691篇 |
出版年
2024年 | 30篇 |
2023年 | 168篇 |
2022年 | 144篇 |
2021年 | 214篇 |
2020年 | 205篇 |
2019年 | 110篇 |
2018年 | 281篇 |
2017年 | 269篇 |
2016年 | 324篇 |
2015年 | 302篇 |
2014年 | 284篇 |
2013年 | 490篇 |
2012年 | 793篇 |
2011年 | 1650篇 |
2010年 | 910篇 |
2009年 | 690篇 |
2008年 | 883篇 |
2007年 | 896篇 |
2006年 | 825篇 |
2005年 | 813篇 |
2004年 | 1495篇 |
2003年 | 1276篇 |
2002年 | 881篇 |
2001年 | 577篇 |
2000年 | 372篇 |
1999年 | 293篇 |
1998年 | 233篇 |
1997年 | 193篇 |
1996年 | 101篇 |
1995年 | 76篇 |
1994年 | 88篇 |
1993年 | 85篇 |
1992年 | 77篇 |
1991年 | 55篇 |
1990年 | 54篇 |
1989年 | 32篇 |
1988年 | 28篇 |
1987年 | 30篇 |
1986年 | 15篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1974年 | 7篇 |
1970年 | 4篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
L. Umapathy G.G. Perez-Carrillo M.B. Keerthivasan J.A. Rosado-Toro M.I. Altbach B. Winegar C. Weinkauf A. Bilgin for the Alzheimers Disease Neuroimaging Initiative 《AJNR. American journal of neuroradiology》2021,42(4):639
BACKGROUND AND PURPOSE:Accurate and reliable detection of white matter hyperintensities and their volume quantification can provide valuable clinical information to assess neurologic disease progression. In this work, a stacked generalization ensemble of orthogonal 3D convolutional neural networks, StackGen-Net, is explored for improving automated detection of white matter hyperintensities in 3D T2-FLAIR images.MATERIALS AND METHODS:Individual convolutional neural networks in StackGen-Net were trained on 2.5D patches from orthogonal reformatting of 3D-FLAIR (n = 21) to yield white matter hyperintensity posteriors. A meta convolutional neural network was trained to learn the functional mapping from orthogonal white matter hyperintensity posteriors to the final white matter hyperintensity prediction. The impact of training data and architecture choices on white matter hyperintensity segmentation performance was systematically evaluated on a test cohort (n = 9). The segmentation performance of StackGen-Net was compared with state-of-the-art convolutional neural network techniques on an independent test cohort from the Alzheimer’s Disease Neuroimaging Initiative-3 (n = 20).RESULTS:StackGen-Net outperformed individual convolutional neural networks in the ensemble and their combination using averaging or majority voting. In a comparison with state-of-the-art white matter hyperintensity segmentation techniques, StackGen-Net achieved a significantly higher Dice score (0.76 [SD, 0.08], F1-lesion (0.74 [SD, 0.13]), and area under precision-recall curve (0.84 [SD, 0.09]), and the lowest absolute volume difference (13.3% [SD, 9.1%]). StackGen-Net performance in Dice scores (median = 0.74) did not significantly differ (P = .22) from interobserver (median = 0.73) variability between 2 experienced neuroradiologists. We found no significant difference (P = .15) in white matter hyperintensity lesion volumes from StackGen-Net predictions and ground truth annotations.CONCLUSIONS:A stacked generalization of convolutional neural networks, utilizing multiplanar lesion information using 2.5D spatial context, greatly improved the segmentation performance of StackGen-Net compared with traditional ensemble techniques and some state-of-the-art deep learning models for 3D-FLAIR.White matter hyperintensities (WMHs) correspond to pathologic features of axonal degeneration, demyelination, and gliosis observed within cerebral white matter.1 Clinically, the extent of WMHs in the brain has been associated with cognitive impairment, Alzheimer’s disease and vascular dementia, and increased risk of stroke.2,3 The detection and quantification of WMH volumes to monitor lesion burden evolution and its correlation with clinical outcomes have been of interest in clinical research.4,5 Although the extent of WMHs can be visually scored,6 the categoric nature of such scoring systems makes quantitative evaluation of disease progression difficult. Manually segmenting WMHs is tedious, prone to inter- and intraobserver variability, and is, in most cases, impractical. Thus, there is an increased interest in developing fast, accurate, and reliable computer-aided automated techniques for WMH segmentation.Convolutional neural network (CNN)-based approaches have been successful in several semantic segmentation tasks in medical imaging.7 Recent works have proposed using deep learning–based methods for segmenting WMHs using 2D-FLAIR images.8-11 More recently, a WMH segmentation challenge12 was also organized (http://wmh.isi.uu.nl/) to facilitate comparison of automated segmentation of WMHs of presumed vascular origin in 2D multislice T2-FLAIR images. Architectures that used an ensemble of separately trained CNNs showed promising results in this challenge, with 3 of the top 5 winners using ensemble-based techniques.12Conventional 2D-FLAIR images are typically acquired with thick slices (3–4 mm) and possible slice gaps. Partial volume effects from a thick slice are likely to affect the detection of smaller lesions, both in-plane and out-of-plane. 3D-FLAIR images, with isotropic resolution, have been shown to achieve higher resolution and contrast-to-noise ratio13 and have shown promising results in MS lesion detection using 3D CNNs.14 Additionally, the isotropic resolution enables viewing and evaluation of the images in multiple planes. This multiplanar reformatting of 3D-FLAIR without the use of interpolating kernels is only possible due to the isotropic nature of the acquisition. Network architectures that use information from the 3 orthogonal views have been explored in recent works for CNN-based segmentation of 3D MR imaging data.15 The use of data from multiple planes allows more spatial context during training without the computational burden associated with full 3D training.16 The use of 3 orthogonal views simultaneously mirrors how humans approach this segmentation task.Ensembles of CNNs have been shown to average away the variances in the solution and the choice of model- and configuration-specific behaviors of CNNs.17 Traditionally, the solutions from these separately trained CNNs are combined by averaging or using a majority consensus. In this work, we propose the use of a stacked generalization framework (StackGen-Net) for combining multiplanar lesion information from 3D CNN ensembles to improve the detection of WMH lesions in 3D-FLAIR. A stacked generalization18 framework learns to combine solutions from individual CNNs in the ensemble. We systematically evaluated the performance of this framework and compared it with traditional ensemble techniques, such as averaging or majority voting, and state-of-the-art deep learning techniques. 相似文献
2.
3.
L. Misery E. Weisshaar E. Brenaut A.W.M. Evers F. Huet S. Ständer A. Reich E. Berardesca E. Serra-Baldrich J. Wallengren D. Linder J.W. Fluhr J.C. Szepietowski H. Maibach for the Special Interest Group on sensitive skin of the International Forum for the Study of Itch 《Journal of the European Academy of Dermatology and Venereology》2020,34(2):222-229
The special interest group on sensitive skin of the International Forum for the Study of Itch previously defined sensitive skin as a syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus and tingling sensations) in response to stimuli that normally should not provoke such sensations. This additional paper focuses on the pathophysiology and the management of sensitive skin. Sensitive skin is not an immunological disorder but is related to alterations of the skin nervous system. Skin barrier abnormalities are frequently associated, but there is no cause and direct relationship. Further studies are needed to better understand the pathophysiology of sensitive skin – as well as the inducing factors. Avoidance of possible triggering factors and the use of well-tolerated cosmetics, especially those containing inhibitors of unpleasant sensations, might be suggested for patients with sensitive skin. The role of psychosocial factors, such as stress or negative expectations, might be relevant for subgroups of patients. To date, there is no clinical trial supporting the use of topical or systemic drugs in sensitive skin. The published data are not sufficient to reach a consensus on sensitive skin management. In general, patients with sensitive skin require a personalized approach, taking into account various biomedical, neural and psychosocial factors affecting sensitive skin. 相似文献
4.
Parallel enzyme‐linked immunosorbent assay screening for human immunodeficiency virus among blood donors in five Chinese blood centres: a retrospective analysis
下载免费PDF全文
![点击此处可从《Transfusion medicine (Oxford, England)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
5.
Emmi Helle Aldo Córdova-Palomera Tiina Ojala Priyanka Saha Praneetha Potiny Stefan Gustafsson Erik Ingelsson Michael Bamshad Deborah Nickerson Jessica X. Chong University of Washington Center for Mendelian Genomics Euan Ashley James R. Priest 《Genetic epidemiology》2019,43(2):215-226
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes. 相似文献
6.
Which infants with eczema are at risk of food allergy? Results from a population‐based cohort
下载免费PDF全文
![点击此处可从《Clinical and experimental allergy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
8.
9.
含左氧氟沙星及卷曲霉素方案治疗耐多药肺结核近期疗效分析 总被引:21,自引:0,他引:21
目的 观察和评价含左氧氟沙星和卷曲霉素联合化疗方案在耐多药肺结核 (MDR PTB)治疗中的疗效。方法 将 177例MDR PTB患者分为治疗组 88例和对照组 89例。化疗方案 :治疗组以左氧氟沙星和卷曲霉素为主 ,联合利福喷汀、异烟肼、对氨基水杨酸钠、吡嗪酰胺 ;对照组用链霉素、乙胺丁醇 ,联用药物同治疗组 ,疗程均为 2 1个月。结果 共有 16 1例患者完成化疗疗程 ,治疗组 82例 ,痰菌阴转率 83% ;对照组 79例 ,痰菌阴转率 5 8% ;痰菌阴转率治疗组明显高于对照组 (P <0 0 1) ;治疗组病灶显效率 5 0 % ,空洞闭合率 6 3% ,治疗组优于对照组 (P <0 0 1) ;治疗组的药物不良反应率为 31% ,对照组为 35 % ,两组比较差异无显著性 (P >0 0 5 )。结论 含左氧氟沙星和卷曲霉素的方案治疗MDR PTB ,有助于痰菌阴转和病变吸收好转 ,药物不良反应低 ,值得在临床上推广应用 相似文献
10.
目的:讨论在院前和急诊科对创伤性休克病人施行早期急救护理,对挽救病人的生命及伤情预后有重要的意义.方法:对我科1997年2月至2001年4月27例创伤性休克病人进行早期,快速,积极的补液,输血增加有效循环量,监测生命体征等综合性抢救治疗与护理措施.结果:经早期积极急救护理,26例病人收缩压维持在60mmHg以上,意识清醒,脉搏有力,转入手术室或专科治疗,1例病人伤势严重抢救无效死亡.结论:创伤性休克病人,伤势复杂,死亡率高,伤后早期院前与急诊科的有效救护,是提高抢救成功率的关键. 相似文献