3,732 research outputs found

    Using MicroPET Imaging in Quantitative Verification of Acupuncture Effect in Ischemia Stroke Treatment

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    While acupuncture has survived several thousand years’ evolution of medical practice, its function still remains as a myth from the view point of modern medicine. Our goal in this paper is to quantitatively understand the function of acupuncture in ischemia stroke treatment. We carried out a comparative study using the Sprague Dawley rat animal model. We induced the focal cerebral ischemia in the rats using the middle cerebral artery occlusion (MCAO) procedure. For each rat from the real acupuncture group (n = 40), sham acupoint treatment group (n = 54), and blank control group (n = 16), we acquired 3-D FDG-microPET images at baseline, after MCAO, and after treatment (i.e., real acupuncture, sham acupoint treatment, or resting according to the group assignment), respectively. After verifying that the injured area is in the right hemisphere of the cerebral cortex in the brain by using magnetic resonance imaging(MRI) and triphenyl tetrazolium cchloride (TTC)-staining, we directly compared the glucose metabolism in the right hemisphere of each rat. We carried out t-test and permutation test on the image data. Both tests demonstrated that acupuncture had a more positive effect than non-acupoint stimulus and blank control (P < 0.025) in increasing the glucose metabolic level in the stroke-injured area in the brain, while there was no statistically significant difference between non-acupoint stimulus and blank control (P>0.15). The immediate positive effect of acupuncture over sham acupoint treatment and blank control is verified using our experiments. The long-term benefit of acupuncture needs to be further studied

    Rare case of magnetic Ag3+^{3+} ion: double perovskite Cs2_{2}KAgF6_{6}

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    Normally 4d4d or 5d5d transition metals are in a low-spin state. Here using first-principles calculations, we report on a rare case of a high-spin SS=1 magnetic state for the Ag3+^{3+} ion in the double perovskite Cs2_{2}KAgF6_{6}. We also explored a possibility of a conventional low-spin SS=0 ground state and find an associated tetragonal distortion to be 0.29 {\AA}. However, the lattice elastic energy cost and the Hund exchange loss exceed the eg_{g} crystal-field energy gain, thus making the low-spin tetragonal structure less favorable than the high-spin cubic structure. We conclude that the compact perovskite structure of Cs2_{2}KAgF6_{6} is an important factor in stabilizing the unusual high-spin ground state of Ag3+^{3+}.Comment: 6 pages, 6 figures, accepted for publication in PR

    Progressive amorphization of GeSbTe phase-change material under electron beam irradiation

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    Fast and reversible phase transitions in chalcogenide phase-change materials (PCMs), in particular, Ge-Sb-Te compounds, are not only of fundamental interests, but also make PCMs based random access memory (PRAM) a leading candidate for non-volatile memory and neuromorphic computing devices. To RESET the memory cell, crystalline Ge-Sb-Te has to undergo phase transitions firstly to a liquid state and then to an amorphous state, corresponding to an abrupt change in electrical resistance. In this work, we demonstrate a progressive amorphization process in GeSb2Te4 thin films under electron beam irradiation on transmission electron microscope (TEM). Melting is shown to be completely absent by the in situ TEM experiments. The progressive amorphization process resembles closely the cumulative crystallization process that accompanies a continuous change in electrical resistance. Our work suggests that if displacement forces can be implemented properly, it should be possible to emulate symmetric neuronal dynamics by using PCMs

    GROUND REACTION FORCE ANALYSIS FOR DIFFERENT FEET POSITION IN BASKETBALL DEFENSIVE-SHUFFLE

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    INTRODUCTION: There are several steps for defending in basketball competition. Defender must shuffle toward lateral rear to defend. We want to understand how the different defensive steps works when defence. The purpose of this study was to collect the ground reaction force while defender shuffling toward lateral rear to find the differences of the different feet position, which we can find the optimal strategy to stop opponent cutting and moving

    IMPRESS: Evaluating the Resilience of Imperceptible Perturbations Against Unauthorized Data Usage in Diffusion-Based Generative AI

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    Diffusion-based image generation models, such as Stable Diffusion or DALL-E 2, are able to learn from given images and generate high-quality samples following the guidance from prompts. For instance, they can be used to create artistic images that mimic the style of an artist based on his/her original artworks or to maliciously edit the original images for fake content. However, such ability also brings serious ethical issues without proper authorization from the owner of the original images. In response, several attempts have been made to protect the original images from such unauthorized data usage by adding imperceptible perturbations, which are designed to mislead the diffusion model and make it unable to properly generate new samples. In this work, we introduce a perturbation purification platform, named IMPRESS, to evaluate the effectiveness of imperceptible perturbations as a protective measure. IMPRESS is based on the key observation that imperceptible perturbations could lead to a perceptible inconsistency between the original image and the diffusion-reconstructed image, which can be used to devise a new optimization strategy for purifying the image, which may weaken the protection of the original image from unauthorized data usage (e.g., style mimicking, malicious editing). The proposed IMPRESS platform offers a comprehensive evaluation of several contemporary protection methods, and can be used as an evaluation platform for future protection methods.Comment: 21 pages, 11 figures, 9 tables. Accepted by NeurIPS 202

    The Bˉs0J/ψπ0η\bar B_s^0 \to J/\psi \pi^0 \eta decay and the a0(980)f0(980)a_0(980)-f_0(980) mixing

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    We study the Bˉs0J/ψf0(980)\bar B_s^0 \to J/\psi f_0(980) and Bˉs0J/ψa0(980)\bar B_s^0 \to J/\psi a_0(980) reactions, and pay attention to the different sources of isospin violation and mixing of f0(980)f_0(980) and a0(980)a_0(980) resonances where these resonances are dynamically generated from meson-meson interaction. We find that the main reason of isospin violation is the isospin breaking in the meson-meson transition TT matrices, and the other source is that the loops involving kaons in the production mechanism provide a source of isospin violation because they do not cancel by the different mass of the charged and neutral kaons. We obtain a branching ratio for a0(980)a_0(980) production of the order of 5×1065 \times 10^{-6}. Future experiments can address this problem and the production rate and shape of the π0η\pi^0 \eta mass distribution will definitely help to better understand the nature of scalar resonances.Comment: 12 pages, 4 figure
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