偏最小二乘(Partial least square,PLS)是一种基于数据驱动可以处理多个因变量对多个自变量的回归建模方法,因其具有提取质量相关信息的特性,在质量相关复杂工业过程监控中得到广泛的应用,成为近几十年复杂工业过程故障检测和诊断领域...偏最小二乘(Partial least square,PLS)是一种基于数据驱动可以处理多个因变量对多个自变量的回归建模方法,因其具有提取质量相关信息的特性,在质量相关复杂工业过程监控中得到广泛的应用,成为近几十年复杂工业过程故障检测和诊断领域的研究热点.对此,介绍线性、非线性、动态PLS模型及其故障检测技术.首先,介绍标准PLS模型,在此基础上对传统PLS模型进行细化分并指出其优缺点,针对标准PLS存在的两个问题以及工业过程数据的两种极端情况,从数据预处理类、多空间类和分块类三方面梳理线性PLS模型的发展和改进历程;其次,将非线性PLS模型扩展方法分为两类,重点介绍核函数非线性PLS模型的研究现状;再次,指出动态扩展方法的两种基本思路,对PLS动态模型进行分类,阐明动态特性的成因,从本质上揭示两种动态扩展方法的原理,按照分类综述动态PLS模型的发展现状;最后,指出该领域亟需解决的问题和未来研究方向.展开更多
Background Bare stent implantation in the treatment for native and recurrent coarctation of the aorta （CoA） has become established as an alternative to surgery and balloon angioplasty. However, this modality still e...Background Bare stent implantation in the treatment for native and recurrent coarctation of the aorta （CoA） has become established as an alternative to surgery and balloon angioplasty. However, this modality still encounters significant complications during the procedure and/or follow-up. The covered Cheatham-Platinum （CP） stent commonly used to be chosen as a rescue treatment in these patients. The purpose of this study was to evaluate the use of covered CP stent as the primary modality in the treatment for native CoA. Methods Twenty-five covered CP stents and 2 bare CP stents were implanted in 25 patients with native CoA. All patients after the intervention were invited for follow-up examinations. Results The peak systolic gradient across the lesion decreased significantly from a median value of 67.5 mmHg （quartile range, 19.3 mmHg） to 2 mmHg （quartile range, 4.0 mmHg） （P 〈0.0001）. Stenotic segment diameter increased from a median value of 5.0 mm （quartile range, 1.5 mm） to 17.9 mm （quartile range, 2.5 mm） （P 〈0.0001）. The median ratio of diameter of the coarctation postprocedure to preprocedure was 4.2 （quartile range, 1.6）. All of the CP stents were placed in the suitable position without any acute complications. During a follow-up period of up to 72 months, no complications were encountered. Most of the patients （21/25） were normotensive, apart from four patients requiring antihypertensive medication during the follow-up. Conclusion The implantation of covered CP stent as the primary modality is safe and effective in the treatment for native CoA in adolescents and adults.展开更多
文摘偏最小二乘(Partial least square,PLS)是一种基于数据驱动可以处理多个因变量对多个自变量的回归建模方法,因其具有提取质量相关信息的特性,在质量相关复杂工业过程监控中得到广泛的应用,成为近几十年复杂工业过程故障检测和诊断领域的研究热点.对此,介绍线性、非线性、动态PLS模型及其故障检测技术.首先,介绍标准PLS模型,在此基础上对传统PLS模型进行细化分并指出其优缺点,针对标准PLS存在的两个问题以及工业过程数据的两种极端情况,从数据预处理类、多空间类和分块类三方面梳理线性PLS模型的发展和改进历程;其次,将非线性PLS模型扩展方法分为两类,重点介绍核函数非线性PLS模型的研究现状;再次,指出动态扩展方法的两种基本思路,对PLS动态模型进行分类,阐明动态特性的成因,从本质上揭示两种动态扩展方法的原理,按照分类综述动态PLS模型的发展现状;最后,指出该领域亟需解决的问题和未来研究方向.
文摘Background Bare stent implantation in the treatment for native and recurrent coarctation of the aorta （CoA） has become established as an alternative to surgery and balloon angioplasty. However, this modality still encounters significant complications during the procedure and/or follow-up. The covered Cheatham-Platinum （CP） stent commonly used to be chosen as a rescue treatment in these patients. The purpose of this study was to evaluate the use of covered CP stent as the primary modality in the treatment for native CoA. Methods Twenty-five covered CP stents and 2 bare CP stents were implanted in 25 patients with native CoA. All patients after the intervention were invited for follow-up examinations. Results The peak systolic gradient across the lesion decreased significantly from a median value of 67.5 mmHg （quartile range, 19.3 mmHg） to 2 mmHg （quartile range, 4.0 mmHg） （P 〈0.0001）. Stenotic segment diameter increased from a median value of 5.0 mm （quartile range, 1.5 mm） to 17.9 mm （quartile range, 2.5 mm） （P 〈0.0001）. The median ratio of diameter of the coarctation postprocedure to preprocedure was 4.2 （quartile range, 1.6）. All of the CP stents were placed in the suitable position without any acute complications. During a follow-up period of up to 72 months, no complications were encountered. Most of the patients （21/25） were normotensive, apart from four patients requiring antihypertensive medication during the follow-up. Conclusion The implantation of covered CP stent as the primary modality is safe and effective in the treatment for native CoA in adolescents and adults.
