Background: Gambling is a popular leisure activity in many countries, often expected to boost regional economies. Nevertheless, its negative impacts remain a significant concern. Gambling disorder is recognized as the most severe consequence; however, even non- or low-risk gamblers may also face negative impacts.
View Article and Find Full Text PDFInternationally, the prevalence of gambling disorder has been reported to be higher among homeless people than the general population; however, little is known about the factors associated with gambling disorder in this population. The present study aimed to investigate the prevalence of gambling disorder and its associated factors among homeless men using shelters in Osaka City. A cross-sectional survey was conducted from 30 to 2018 to 4 January 2019, using the 2017 Japanese National Survey of Gambling (JNSG) questionnaire, supplemented with questions about homeless experiences, drinking, and smoking.
View Article and Find Full Text PDFBackground: The efficacy of brief intervention (BI) for unhealthy drug use in outpatient medical care has not been sufficiently substantiated through meta-analysis despite its ongoing global delivery. This study aims to determine the efficacy of BI for unhealthy drug use and the expected length of effects, and describe subgroup analyses by outpatient setting.
Methods: Trials comparing BI with usual care controls were retrieved through four databases up to January 13, 2021.
Introduction: Drug misuse is associated with significant global morbidity, mortality, economic costs and social costs. Many primary care facilities have integrated drug misuse screening and brief intervention (BI) into their usual care delivery. However, the efficacy of BI for drug misuse in primary care has not been substantiated through meta-analysis.
View Article and Find Full Text PDFCorrection for 'Rewritable full-color computer-generated holograms based on color-selective diffractive optical components including phase-change materials' by Chi-Young Hwang et al., Nanoscale, 2018, DOI: 10.1039/c8nr04471f.
View Article and Find Full Text PDFWe propose rewritable full-color computer-generated holograms (CGHs) based on color-selective diffraction using the diffractive optical component with the resonant characteristic. The structure includes an ultrathin layer of phase-change material Ge2Sb2Te5 (GST) on which a spatial binary pattern of amorphous and crystalline states can be recorded. The CGH patterns can be easily erased and rewritten by the pulsed ultraviolet laser writing technique owing to the thermally reconfigurable characteristic of GST.
View Article and Find Full Text PDFA phase modulation device was proposed for the implementation of hologram image for display applications. A Ge2Sb2Te5 (GST) film as thin as 7 nm was prepared between the ITO films to form the cavities corresponding a unit pixel. Nitrogen was incorporated into the GST for improving the thermal stability of the GST active region.
View Article and Find Full Text PDFvan der Waals (vdW) heterostructures with two-dimensional (2D) crystals such as graphene, hexagonal boron nitride (hBN) and transition metal dichalcogenides (TMDCs) allow us to demonstrate atomically thin field-effect transistors (FETs), photodetectors (PDs) and photovoltaic devices capable of higher performance and greater stability levels than conventional devices. Although there have been studies of gas molecule sensing with 2D crystal channels, vdW heterostructures based on 2D crystals have not been employed thus far. Here, utilizing graphene/WS/graphene (G/WS/G) vdW heterostructure tunnel FETs, we demonstrate the rectification behavior of the sensitivity signal by tuning the WS potential barriers as a function of the gas molecule concentration and devise a fingerprint map of the sensitivity variation corresponding to an individual ratio of two different molecules in a gas mixture.
View Article and Find Full Text PDFThe development of digital holography is anticipated for the viewing of 3D images by reconstructing both the amplitude and phase information of the object. Compared to analog holograms written by a laser interference, digital hologram technology has the potential to realize a moving 3D image using a spatial light modulator. However, to ensure a high-resolution 3D image with a large viewing angle, the hologram panel requires a near-wavelength scale pixel pitch with a sufficient large numbers of pixels.
View Article and Find Full Text PDFWe present a method for reflection-type spatial amplitude modulation using a sub-wavelength plasmonic absorber structure that can operate in the visible region. We utilize a pixelated array of absorbing elements based on a two-dimensional sub-wavelength metal grating, and the reflectance of each pixel is controlled by simple structural modification. For the purpose of validation, numerical simulations were performed on an amplitude modulation hologram fabricated using our method.
View Article and Find Full Text PDFA novel fast frequency-based method to estimate the focus distance of digital hologram for a single object is proposed. The focus distance is computed by analyzing the distribution of intersections of smoothed-rays. The smoothed-rays are determined by the directions of energy flow which are computed from local spatial frequency spectrum based on the windowed Fourier transform.
View Article and Find Full Text PDFA method is proposed for the construction of a square pixel complex spatial light modulator (SLM) from a commercial oblong full-high-definition (full-HD) amplitude SLM using an anamorphic optical filter. In the proposed scheme, one half-band of the optical Fourier transform of the amplitude-only spatial light field is rejected in the optical Fourier plane and the other half-band is reformatted to be an effective complex SLM with square pixels. This has an advantage in the viewing window plane since the shape of the viewing window becomes square and more ideal for observers who watch the hologram contents through it.
View Article and Find Full Text PDFWe present a method to calculate wave propagation between arbitrary curved surfaces using a staircase approximation approach. The entire curved surface is divided into multiple subregions and each curved subregion is approximated by a piecewise flat subplane allowing the application of conventional diffraction theory. In addition, in order to reflect the local curvature of each subregion, we apply the phase compensation technique.
View Article and Find Full Text PDFA polarization-dependent switchable plasmonic beaming structure composed of metallic hole surrounded by double spiral dielectric gratings is proposed. The main mechanism of the proposed structure is based on the angular momentum change of surface plasmon caused by the spiral geometry. On- and off-states of the proposed device are determined by the condition whether the rotating direction of incident polarization is the same as or opposite of the direction of the spiral rotations.
View Article and Find Full Text PDFWe propose a way of generating Bessel-like non-diffracting beams based on the superposition of multiple Airy beams. We also demonstrate, through numerical simulations of the propagation dynamics of the Bessel-like beams, that these Bessel-like beams can be modified to show the feature of vortex power flow by controlling the initial positions of each single Airy beam.
View Article and Find Full Text PDFWe show that in plasmonic or metamaterial slab waveguides, it is possible to generate slow non-dispersing wavepackets which undergo neither spatial diffraction nor temporal spreading with no nonlinear effects by forming a type of hybrid wavepacket between slow-light waveguide modes and diffraction-free Airy wavepackets. Three mechanisms are involved in their slowness: the slow-light feature of waveguide modes, the initial launching speed of hybrid wavepackets, and their acceleration along the time domain in a moving frame.
View Article and Find Full Text PDFWe derive a general form of Airy wave function which satisfies paraxial equation of diffraction. Based on this, we propose a new form of Airy beam, which is composed of two symmetrical Airy beams which accelerate mutually in the opposite directions. This 'dual' Airy beam shows several distinguishing features: it has a symmetric transverse intensity pattern and improved self-regeneration property.
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