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Evaluation of mitral chordae tendineae length using four-dimensional computed

World Journal of Cardiology 2024年第5期16卷 274-281页

作者： Takuya Mori Satoshi Matsushita Terumasa Morita Abulaiti Abudurezake Junji Mochizuki Atsushi Amano Department of Cardiovascular Surgery Juntendo University Faculty of MedicineTokyo 113-8421Japan Department of Cardiovascular Surgery JACCT Japan Animal Cardiovascular Care TeamOsaka 533-0033Japan Department of Radiology Minamino Cardiovascular HospitalTokyo 192-0918Japan

BACKGROUND Mitral valvuloplasty using artificial chordae tendineae represents an effective surgical approach for treating mitral *** precise measurements of artificial chordae tendineae length(CL)is an important factor in the procedure;however,no objective index currently exists to facilitate this ***,preoperative assessment of CL is critical for surgical planning and ***-dimensional x-ray micro-computed tomography(4D-CT)may be useful for accurate CL measurement considering that it allows for dynamic three-dimensional(3D)evaluation compared to that with transthoracic echocardiography,a conventional inspection *** To investigate the behavior and length of mitral chordae tendineae during systole using *** Eleven adults aged>70 years without mitral valve disease were evaluated.A 64-slice CT scanner was used to capture 20 phases in the cardiac cycle in electrocardiographic *** length of the primary chordae tendineae was measured from early systole to early diastole using the 3D *** primary chordae tendineae originating from the anterior papillary muscle and attached to the A1-2 region and those from the posterior papillary muscle and attached to the A2-3 region were designated as cA and cP,*** behavior and maximum lengths[cA(ma),cP(max)]were compared,and the correlation with body surface area(BSA)was *** In all cases,the mitral anterior leaflet chordae tendineae could be *** most cases,the cA and cP chordae tendineae could be measured *** mean cA(max)and cP(max)were 20.2 mm±1.95 mm and 23.5 mm±4.06 mm,***(max)was significantly *** correlation coefficients(r)with BSA were 0.60 and 0.78 for cA(max)and cP(max),*** cA and cP exhibited constant variation in CL during systole,with a maximum 1.16-fold increase in cA and a 1.23-fold increase in cP from early to *** cP,CL reached a plateau at 15%and remaine

关键词： Mitral valve Chordae tendineae Computed tomography four-dimensional Cardiac cycle

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OPERATOR NORM AND LOWER BOUND OF four-dimensional GENERALIZED HAUSDORFF MATRICES

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Acta Mathematica Scientia 2022年第1期42卷 429-436页

作者： Gholamreza TALEBI Department of Mathematical sciences Vali-e-Asr University of RafsanjanRafsanjanIslamic Republic of Iran

The problem addressed is the exact determination of the operator norm and lower bound of four-dimensional generalized Hausdorff matrices on the double sequence spaces L_(p).A Hardy type formulae is found as an exact value for their operator norm and a Copson type formulae is established as a lower estimate for their lower ***,exact values are found for the operator norm and lower bound of the transpose of generalized Hausdorff matrices.

关键词： four-dimensional Hausdorff matrices

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four-dimensional flow magnetic resonance imaging incirrhosis

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World Journal of Gastroenterology 2016年第1期22卷 89-102页

作者： Zoran Stankovic University Institute of Diagnostic Interventional and Pediatric RadiologyInselspital-University Hospital Bern3010 BernSwitzerland

Since its introduction in the 1970’s,magnetic resonance imaging(MRI)has become a standard imaging *** its broad and standardized application,it is firmly established in the clinical routine and an essential element in cardiovascular and abdominal *** addition to sonography and computer tomography,MRI is a valuable tool for diagnosing cardiovascular and abdominal diseases,for determining disease severity,and for assessing therapeutic *** techniques have improved over the last few decades,revealing not just morphologic information,but functional information about perfusion,diffusion and hemodynamics as ***-dimensional(4D)flow MRI,a time-resolved phase contrast-MRI with three-dimensional(3D)anatomic coverage and velocity encoding along all three flow directions has been used to comprehensively assess complex cardiovascular hemodynamics in multiple regions of the *** technique enables visualization of 3D blood flow patterns and retrospective quantification of blood flow parameters in a region of *** the last few years,4D flow MRI has been increasingly performed in the abdominal *** applying different acceleration techniques,taking 4D flow MRI measurements has dropped to a reasonable scanning time of 8 to 12 *** new developments have encouraged a growing number of patient studies in the literature validating the technique’s potential for enhanced evaluation of blood flow parameters within the liver’s complex vascular *** purpose of this review article is to broaden our understanding of 4D flow MRI for the assessment of liver hemodynamics by providing insights into acquisition,data analysis,visualization and ***,in this article we highlight its development,focussing on the clinical application of the technique.

关键词： four-dimensional flow magnetic resonanceimaging Phase contrast-magnetic resonance imaging Liver cirrhosis Imaging technique Hemodynamics Bloodflow Visualization Quantification TIPS Splanchnic system

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An explicit four-dimensional variational data assimilation method

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Science China Earth Sciences 2007年第8期50卷 1232-1240页

作者： QIU ChongJian ZHANG Lei SHAO AiMei Key Laboratory of Arid Climatic Changing and Reducing Disaster of Gansu Province College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China

A new data assimilation method called the explicit four-dimensional variational (4DVAR) method is proposed. In this method, the singular value decomposition (SVD) is used to construct the orthogonal basis vectors from a forecast ensemble in a 4D space. The basis vectors represent not only the spatial structure of the analysis variables but also the temporal evolution. After the analysis variables are ex-pressed by a truncated expansion of the basis vectors in the 4D space, the control variables in the cost function appear explicitly, so that the adjoint model, which is used to derive the gradient of cost func-tion with respect to the control variables, is no longer needed. The new technique significantly simpli-fies the data assimilation process. The advantage of the proposed method is demonstrated by several experiments using a shallow water numerical model and the results are compared with those of the conventional 4DVAR. It is shown that when the observation points are very dense, the conventional 4DVAR is better than the proposed method. However, when the observation points are sparse, the proposed method performs better. The sensitivity of the proposed method with respect to errors in the observations and the numerical model is lower than that of the conventional method.

关键词： data assimilation four-dimensional variation explicit method singular value decomposition shallow water equation

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Deep Volatiles as the Key for Energy and Environments of the four-dimensional Earth System

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Engineering 2019年第3期5卷 393-394页

作者： Ho-Kwang Mao Craig M. Schiffries Center for High Pressure Science and Technology Advanced Research (HPSTAR) Shanghai 201203 China Geophysical Laboratory Carnegie Institution for Science Washington DC 20015 USA

Carbon, hydrogen, oxygen, nitrogen, sulfur, and their compounds are volatile components that dominate the thin and fragile atmosphere, hydrosphere, and biosphere on Earth’s habitable surface. However, the vast majority of these volatiles are hidden in the deep interior, where the high pressure–temperature conditions drastically and categorically alter the physics and chemistry of the volatiles. Like the bloodstream of an organism, the circulations and interactions of volatiles in the deep Earth modulate climate, resources, energy, natural hazards, and other factors that define the Earth as a unique living and changing planet.

关键词： four-dimensional Earth System Deep Volatiles

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Forming proper ensemble forecast initial members with four-dimensional variational data assimilation method

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Chinese Science Bulletin 1999年第16期44卷 1527-1531页

作者： Jiandong Gong Weijing Li Jifan Chou Natl Climate Ctr Beijing 100081 Peoples R China Lanzhou Univ Dept Atmospher Sci Lanzhou 730000 Peoples R China

A method has been presented to improve ensemble forecast by utilizing these initial members generated by four-dimensional variational data assimilation (4-D VDA), to conquer limitation of those initial members generated by Monte Carlo forecast (MCF) or lagged average forecast (LAF). This method possesses significant statistical characteristic of MCF, and by virtue of LAF that contains multi-time information and its initial members are harmonic with

关键词： ensemble forecast initial member generating four-dimensional variational data assimilation method numeri-cal forecast experiments.

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DYNAMICAL BEHAVIORS OF A four-dimensional SYSTEM IN INFECTIOUS DISEASE

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Systems Science and Mathematical Sciences 1995年第2期8卷 102-115页

作者： LIN Yiping(Yunnan Institute of Applied Mathematics,Kunming Institute of Technology,Kunming 650093, China)JING Zhujun(Institute of Mathematics, Academia Sinica, Beijing 100080,China) 云南省应用数学所云南昆明中科院数学所北京

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关键词： Equilibria bifUrcation Hopf bifurcation four-dimensional infectious disease System

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Clinical effect of four-dimensional therapy on patients with cervical hypertension

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Journal of Hainan Medical University 2019年第13期25卷 25-30页

作者： You-Xue Wang Qi Qin Dong-Wei Wang Yu Chen Department of Orthopaedics The Seventh People’s Hospital of ShenyangShenyang11034Liaoning ProvinceChina Department of Orthopaedics The Second Affiliated Hospital to Liaoning University of Chinese MedicineShenyang110003Liaoning ProvinceChina

Objective:To research the effect of four-dimensional therapy on the clinical effect (symptoms, blood pressure, and pain degree), the changes of blood rheology and arterial (left vertebral artery (LVA), right vertebral artery (RVA), and basal artery (BA)) hemodynamics (average cerebral blood flow (Vm), resistance index (RI), pulsatility index (PI)) on patients with cervical hypertension. Method: Selecting 120 patients (Department of Orthopaedics, the second Affiliated Hospital to Liaoning University of Chinese Medicine, 2012.6-2018.10) with cervical hypertension, then they were divided into observation group (n=60) and control group (n=60). The control group were given enalapril meleate (amlodipine besylate) +conventional therapy (acupuncture treatment and massage), the observation group were given four-dimensional therapy on the basic of control group, they were treated 3 weeks. The primary endpoints were the changes from baseline to week 3 in the symptoms and function were scored using the Evaluation Scale for Cervical Vertigo, the secondary endpoints were changes from baseline to month 3 in the artery hemodynamics (Vm, RI, and PI) in the BA, LVA, blood rheology, and RVA. At last, assessing the pain degree through visual analog scale (VAS), measuring the blood pressure, and accessing the clinical ***:The score of vertigo in the two groups had no statistical significance before treatment, the score of vertigo in the two groups were higher than pretherapy, and had statistical significance, and the score in the observation group were higher than control group, and had statistical significance. The hemodynamics (Vm, RI, and PI) in the artery (BA, LVA, and RVA) had no statistical significance in the two groups before treatment, and the hemodynamics (Vm) in the artery (BA, LVA, and RVA) were higher than pretherapy, and had statistical significance, the hemodynamics (Vm) in the artery (BA, LVA, and RVA) of observation group were higher than control group, and h

关键词： four-dimensional therapy Cervical hypertension Hemodynamics Blood rheology

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The Role of Cultural Compatibility in Effective Management The Application of Cultural four-dimensional Model in Transnational Corporations

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西安翻译学院学报 2015年第1期22卷 64-68页

作者：成哲比利时安特卫普大学

Cross-cultural management is often regarded as a discipline of international management focusing on cultural encounters between the organization and the nation-state, and providing tools to tackle cultural difl＇erences seen as sources of conflict, friction or misunderstanding. Based on Greet Hofstede＇ s Cultural Model, this paper attempts to shed some light on effective corporation management through cultural analysis of the difl＇erences between China and western countries. The paper puts more emphasis on the impact of cultural compatibility on effective corporation man- agement through the case study of China, Japan, Germany and America. The author argues that managers and employ- ees involved in companies with diverse cultural backgrounds should be integrated and developed into a specific local context through interlocking their cultural identifications and the organizational practices.

关键词： Cultural differences Cultural four-dimensional Model Cultural Compatibility Cross-cultural Man-agement

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Application value of four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging in screening fetal congenital heart disease

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Journal of Hainan Medical University 2019年第12期25卷 71-73页

作者： Yi-Nan Chen Jiang-Jun Qin Ying-Mei Qin Huai-Chun Chen Cun Chen Li-Fei Lin Department of Ultrasound Sanya City Womenfolk&Infant Health Care HospitalSanya572000HainanChina Department of Radiology the Third People's Hospital of Hainan ProvinceSanya572000HainanChina

Objective:To explore the value of four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging in screening fetal congenital heart ***: A total of 671 pregnant women at 22-24 gestational weeks from January 2018 to December 2018 were examined by two-dimensional ultrasound and four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging to observe the development of fetal cardiovascular structure and to compare the two methods in terms of diagnostic accuracy, examination time, image quality and new physician training ***: Cardiac malformations were found in 12 of the 671 fetuses, among which 11 cases were detected by four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging and 1 case was missed. Postnatal echocardiographic reexamination and autopsy confirmed 12 cases of children with cardiac malformation, including 1 case of atrial septal defect (missed diagnosis by four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging), 4 cases of tetralogy of Fallot's disease, 1 case of right ventricular double outlet, 3 cases of left ventricular dysplasia, 2 cases of complete transposition of the great artery and 1 case of tricuspid valve descending malformation. There was no statistically significant difference between four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging and conventional two-dimensional color echocardiography or/and autopsy (P>0.05). In terms of examination time and new physician training, the four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging technique was superior to conventional color ultrasound screening. No statistically significant difference in image ***:The four-dimensional spatiotemporal image correlation and tomographic ultrasound imaging can rapidly and accurately display fetal heart development, and can be used as the main screening method for f

关键词： four-dimensional spatiotemporal image correlation Ultrasound Fetus Cardiac abnormalities

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