Four-Dimensional Flow Magnetic Resonance Imaging and Applications in Cardiology

Blood flow through the heart and great vessels moves in three dimensions (3D) throughout time. However, the assessment of its 3D nature has been limited in the human body. Recent advances in magnetic resonance imaging (MRI) allow for the comprehensive visualization and quantification of in-vivo flow dynamics using four-dimensional (4D) flow MRI. In addition, this technique provides the opportunity to obtain advanced hemodynamic biomarkers such as vorticity, helicity, wall shear stress (WSS), pressure gradients, viscous energy loss (EL), and turbulent kinetic energy (TKE). This chapter will introduce 4D flow MRI which is currently used for blood flow visualization and advanced quantification of cardiac hemodynamic biomarkers. We will discuss its advantages relative to other in-vivo flow imaging techniques and describe its potential clinical applications in cardiology

GENERATION EXPANSION PLANNING USING BENDERS’ DECOMPOSITION AND GENERALIZED NETWORKS

This paper presents an optimization model and its application to a generation expansion planning problem. The proposed model has a generalized network structure and is exploited effectively by Benders’ decomposition algorithm, where a master problem generates trial expansion plans and a set of subproblems compute production cost and system reliability for the trial plan. The applicability of our decomposition algorithm is demonstrated in the case study of Korea's generation expansion planning. The results demonstrate that the model is a practical and flexible tool in solving realistic long-range generation planning problems

Cardiovascular Magnetic Resonance Imaging of Atrial Fibrillation: An Advanced Hemodynamic Perspective

Atrial fibrillation (AF) patients can be referred to cardiac magnetic resonance imaging (MRI) for an accurate assessment of cardiac function and left atrial structure. Cardiac MRI is the gold standard for the quantification of heart volumes and allows the noninvasive tissue characterization of the heart. In addition, advanced flow assessment can be achieved using 4D-flow MRI to elegantly depict the hemodynamic efficiency of the left atrium (LA) and left ventricle (LV) throughout the cardiac cycle. Patients with AF may have occult LV disease and thrombus formation. Biomarkers based on 4D-flow MRI may unmask the presence of LA/LV disease by quantifying 3D stasis, flow distribution, and vortex formation. These biomarkers have proved to characterize AF stages, to complement standard risk scores, and bring new insights on heart hemodynamic performance. This chapter aims to present a standard cardiac MRI protocol for atrial fibrillation and the innovative usefulness of advanced flow imaging in clinical settings

A Scoping Review of the Conceptual Differentiation of Technology for Healthy Aging.

BACKGROUND AND OBJECTIVES: With the emergence of healthy aging as a key societal issue in recent decades, technology has often been proposed as a solution to the challenges faced by aging societies. From a public health perspective, however, aging-related technologies have been inconsistently conceptualized and ill-defined. By examining how relevant concepts in "technology for aging" have been developed to date, we hope to identify gaps and begin clarifying the topic. RESEARCH DESIGN AND METHODS: We conducted a scoping review according to PRISMA-ScR, drawing on PubMed and Embase. We selected articles that directly reported concepts of technology for aging, or from which such concepts could be inferred. RESULTS: We identified 43 articles, most of which were narrative reviews (n = 31). Concepts of technology for aging were presented in diverse ways with some overlap. Most studies provided some terminology (n = 36), but with little conceptual uniformity. Conceptual discourse was often focused on the aging agenda; while technological aspects were poorly defined. A conceptual framework from a public health perspective was derived from 8 articles-it showed that technology strategies do not take a population approach. DISCUSSION AND IMPLICATIONS: While the potential of "technology for aging" is vast, its real capacity to deliver a desirable life for older people remains underdeveloped. Clearer concepts and realistic goals at population level are lacking. Efficient investment must be made throughout the social system, and technology needs to be integrated via macro-level practices

Multiple Polymorphic Loci for Molecular Typing of Strains of Mycobacterium leprae

The need for molecular tools for the differentiation of isolates of Mycobacterium leprae, the organism that causes leprosy, is urgent in view of the continuing high levels of new case detection, despite years of aggressive chemotherapy and the consequent reduction in the prevalence of leprosy. The slow onset of leprosy and the reliance on physical examination for detection of disease have restricted the epidemiological tracking necessary to understand and control transmission. Two genetic loci in several isolates of M. leprae have previously been demonstrated to contain variable-number tandem repeats (VNTRs). On the basis of these reports and the availability of the full genome sequence, multiple-locus VNTR analysis for strain typing has been undertaken. A panel of 11 short tandem repeat (STR) loci with repeat units of 1, 2, 3, 6, 12, 18, 21, and 27 bp from four clinical isolates of M. leprae propagated in armadillo hosts were screened by PCR. Fragment length polymorphisms were detected at 9 of the 11 loci by agarose gel electrophoresis. Sequencing of representative DNA products confirmed the presence of VNTRs between isolates. The application of nine new polymorphic STRs in conjunction with automated methods for electrophoresis and size determination allows greater discrimination between isolates of M. leprae and enhances the potential of this technique to track the transmission of leprosy