Skyrmion Generation by Current

Skyrmions, once a hypothesized field-theoretical object believed to describe the nature of elementary particles, became common sightings in recent years among several non-centrosymmetric metallic ferromagnets. For more practical applications of Skyrmionic matter as carriers of information, thus realizing the prospect of "Skyrmionics", it is necessary to have the means to create and manipulate Skyrmions individually. We show through extensive simulation of the Landau-Lifshitz-Gilbert equation that a circulating current imparted to the metallic chiral ferromagnetic system can create isolated Skyrmionic spin texture without the aid of external magnetic field.Comment: 8 pages, 5 figures, submitted to PR

Aging Risk and Health Care Expenditure in Korea

This paper analyzes the impact of population aging on health care expenditures in Korea. Examination of the age-expenditure profile reveals that health care resources are allocated more for the older cohort of population over time, suggesting significant growth of health care expenditures due to population aging. We contend, however, that population aging is considered as a parameter rather than an independent variable to explain rising health care expenditures. This paper shows that population aging is not found to be a significant determinant of health care expenditures according to the econometric analysis using OECD health data and time-series data for Korea. Using the components decomposition method, which measures the contribution of each component of health care expenditure, we estimate that population aging contributes only less than 10 percent

Impact of population ageing on the cost of hospitalisations for cardiovascular disease: a population-based data linkage study

Background: Cardiovascular disease (CVD) is the most costly disease in Australia. Measuring the impact of ageing on its costs is needed for planning future healthcare budget. The aim of this study was to measure the impact of changes in population age structure in Western Australia (WA) on the costs of hospitalisation for CVD. Methods: All hospitalisation records for CVD occurring in WA in 1993/94 and 2003/04 inclusive were extracted from the WA Hospital Morbidity Data System (HMDS) via the WA Data Linkage System. Inflation adjusted hospitalisation costs using 2012 as the base year was assigned to all episodes of care using Australian Refined Diagnosis Related Group (AR-DRG) costing information. The component decomposition method was used to measure the contribution of ageing and other factors to the increase of hospitalisation costs for CVD. Results: Between 1993/94 and 2003/04, population ageing contributed 23% and 30% respectively of the increase in CVD hospitalisation costs for men and women. The impact of ageing on hospitalisation costs was far greater for chronic conditions than acute coronary syndrome (ACS) and stroke. Conclusions: Given the impact of ageing on hospitalisation costs, and the disparity between chronic and acute conditions, disease-specific factors should be considered in planning for future healthcare expenditure

Ultra-Sharp Nanowire Arrays Natively Permeate, Record, and Stimulate Intracellular Activity in Neuronal and Cardiac Networks

Intracellular access with high spatiotemporal resolution can enhance our understanding of how neurons or cardiomyocytes regulate and orchestrate network activity, and how this activity can be affected with pharmacology or other interventional modalities. Nanoscale devices often employ electroporation to transiently permeate the cell membrane and record intracellular potentials, which tend to decrease rapidly to extracellular potential amplitudes with time. Here, we report innovative scalable, vertical, ultra-sharp nanowire arrays that are individually addressable to enable long-term, native recordings of intracellular potentials. We report large action potential amplitudes that are indicative of intracellular access from 3D tissue-like networks of neurons and cardiomyocytes across recording days and that do not decrease to extracellular amplitudes for the duration of the recording of several minutes. Our findings are validated with cross-sectional microscopy, pharmacology, and electrical interventions. Our experiments and simulations demonstrate that individual electrical addressability of nanowires is necessary for high-fidelity intracellular electrophysiological recordings. This study advances our understanding of and control over high-quality multi-channel intracellular recordings, and paves the way toward predictive, high-throughput, and low-cost electrophysiological drug screening platforms.Comment: Main manuscript: 33 pages, 4 figures, Supporting information: 43 pages, 27 figures, Submitted to Advanced Material

Individually addressable and flexible pressure sensor matrixes with ZnO nanotube arrays on graphene

We report the fabrication of individually addressable, high-density, vertical zinc oxide (ZnO) nanotube pressure sensor arrays. High-sensitivity and flexible piezoelectric sensors were fabricated using dimension- and position-controlled, vertical, and free-standing ZnO nanotubes on a graphene substrate. Significant pressure/force responses were achieved from small devices composed of only single, 3 × 3, 5 × 5, and 250 × 250 ZnO nanotube arrays on graphene. An individually addressable pixel matrix was fabricated by arranging the top and bottom electrodes of the sensors in a crossbar configuration. We investigated the uniformity and robustness of pressure/force spatial mapping by considering the pixel size, the number of ZnO nanotubes in each pixel, and the lateral dimensions of individual ZnO nanotubes. A spatial resolution as high as 1058 dpi was achieved for a Schottky diode-based force/pressure sensor composed of ZnO nanotubes on a flexible substrate. Additionally, we confirmed the excellent flexibility and electrical robustness of the free-standing sensor arrays for high-resolution tactile imaging. We believe that this work opens important opportunities for 1D piezoelectric pressure/force sensor arrays with enormous applications in human-electronics interfaces, smart skin, and micro- and nanoelectromechanical systems

Codes for 'An electroencephalogram microdisplay to visualize neuronal activity on the brain surface'

<div> <div> <p>These codes are utilized to operate the iEEG-microdisplay and produce the figures featured in the publication titled 'An electroencephalogram microdisplay to visualize neuronal activity on the brain surface'. </p> </div> </div&gt