简介:摘 要:萧红的《回忆鲁迅先生》堪称经典名篇。学情调查阶段,学生对于文本的浅薄认知,导致不解甚至误解,质疑之声此起彼伏。引导七年级阶段的学生回归文本,领略“平淡中的不平淡”、朴拙中的本味、寻常背后的深情,教师必须从学情出发,秉承“长文短教,繁文简教”的原则,以语言为核心,以语言活动为主体,尊重学生经验,以学生喜欢的方式来教学。引导学生在质疑经典的问难声中,拨开迷雾,了解作家萧红独立特行的散文风格:片段化、细节化、情绪化,提升学生的语文素养,向经典致敬!
简介:摘要:深度学习已广泛应用于医学成像的分割中。2015年提出的U-Net模型显示了精确分割小目标及其网络架构可扩展的优势,使其成为医学成像分割任务的主要工具。近年来,随着对医学图像分割性能要求的不断提高,研究人员通过采用新方法或将引入其他方法等手段,从结构、创新性、效率等方面对U-Net架构进行了许多进步。U-Net的成功之处在于它在MRI、CT、眼底成像、超声图像和X射线等几乎所有主要图像模式中被广泛应用,并有巨大的发展潜力。
简介:摘要:糖尿病视网膜病变 (DR) 是一种严重的眼部异常,其严重情况下会导致视网膜脱落甚至失明。眼底的渗出液是由于高血糖毒性作用,导致血屏障破坏,血管内的脂质等漏出而造成的。是视网膜病变的并发症之一。由于患者与专业医生数量悬殊巨大,设计一个可以自动的检测渗出液的医疗助手是十分重要的任务。本文依托于深度学习方法,以U-Net架构为骨架网络,以准确度 (Acc)、灵敏度 (SE)、特异性 (SP)以及AUC值作为模型性能的评估指标,先测试了原始U-Net在该任务上的分割能力,在该任务上达到99.8%的准确度,73.1%的灵敏度,98.0%的特异性以及0.973的AUC值。根据U-Net网络架构的固有问题,将Attention机制与U-Net结构,搭建Attention U-Net。99.8%的准确度,81.5%的灵敏度,99.8%的特异性以及0.985的AUC值。实验结果表明,Attention U-Net有更好的特征提取能力。
简介:【摘要】专业技术人员能力传统的评价系统大多是人工操作的,而且需要很多纸质材料的辅助。评估过程复杂繁琐,并且效率底下。因此开发一个计算机和网络技术的评
简介:AbstractBackground:Chromosomal abnormalities are important causes of ventriculomegaly (VM). In mild and isolated cases of fetal VM, obstetricians rarely give clear indications for pregnancy termination. We aimed to calculate the incidence of chromosomal abnormalities and incremental yield of chromosomal microarray analysis (CMA) in VM, providing more information on genetic counseling and prognostic evaluation for fetuses with VM.Methods:The Chinese language databases Wanfang Data, China National Knowledge Infrastructure, and China Biomedical Literature Database (from January 1, 1991 to April 29, 2020) and English language databases PubMed, Embase, and Cochrane Library (from January 1, 1945 to April 29, 2020) were systematically searched for articles on fetal VM. Diagnostic criteria were based on ultrasonographic or magnetic resonance imaging (MRI) assessment of lateral ventricular atrium width: ≥10 to <15 mm for mild VM, and ≥15 mm for severe VM. Isolated VM was defined by the absence of structural abnormalities other than VM detected by ultrasonography or MRI. R software was used for the meta-analysis to determine the incidence of chromosomal abnormalities and incremental yield of CMA in VM, and the combined rate and 95% confidence interval (CI) were calculated.Results:Twenty-three articles involving 1635 patients were included. The incidence of chromosomal abnormalities in VM was 9% (95% CI: 5%-12%) and incremental yield of CMA in VM was 11% (95% CI: 7%-16%). The incidences of chromosomal abnormalities in mild, severe, isolated, and non-isolated VM were 9% (95% CI: 4%-16%), 5% (95% CI: 1%-11%), 3% (95% CI: 1%-6%), and 13% (95% CI: 4%-25%), respectively.Conclusions:Applying CMA in VM improved the detection rate of abnormalities. When VM is confirmed by ultrasound or MRI, obstetricians should recommend fetal karyotype analysis to exclude chromosomal abnormalities. Moreover, CMA should be recommended preferentially in pregnant women with fetal VM who are undergoing invasive prenatal diagnosis. CMA cannot completely replace chromosome karyotype analysis.