5,771 research outputs found

    Quantum Hall Effects in a Non-Abelian Honeycomb Lattice

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    We study the tunable quantum Hall effects in a non-Abelian honeycomb optical lattice which is a many-Dirac-points system. We find that the quantum Hall effects present different features as change as relative strengths of several perturbations. Namely, a gauge-field-dressed next-nearest-neighbor hopping can induce the quantum spin Hall effect and a Zeeman field can induce a so-called quantum anomalous valley Hall effect which includes two copies of quantum Hall states with opposite Chern numbers and counter-propagating edge states. Our study extends the borders of the field of quantum Hall effects in honeycomb optical lattice when the internal valley degrees of freedom enlarge.Comment: 7 pages, 6 figure

    Retinal Ischemia: MMP-9; Its Relation to Resveratrol, Baicalein, S-allyl L-cysteine and Chi Ju Di Huang Wan

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    Ischemia has been reported to be related to matrix metalloproteinase-9 (MMP-9) level upregulation. Neovascular glaucoma (NVG) (in proliferative diabetic retinopathy and central/branch retinal vein occlusion) and age-related macular degeneration are known vision-threatening retinal ischemic disorders. In this review, an extensive discussion has been made into how MMP-9 is related to retinal ischemia and what the underlying mechanisms of various traditional Chinese medicine (TCM) compounds and combinations are. High intraocular pressure-induced retinal ischemic changes were characterized by decreased electroretinogram (ERG) b-wave amplitudes, a loss of choline acetyltransferase (ChAT) immunopositive amacrine neurons/processes, increased Müller’s vimentin immunoreactivity, and profound retinal ganglion cell (RGC) death. It has also been observed hypoxia inducible factor-1α (HIF-1α), MMP-9 and vascular endothelium growth factor (VEGF) upregulation at the protein/mRNA levels. After ischemia, both the p38 mitogen-activated protein kinases (MAPKs)-stimulated MMP-9 upregulation and HIF-1α-triggered VEGF overexpression might result in neovascularization. Conclusively, baicalein seems to have neuroprotection via antioxidation, antiapoptosis, HO-1 upregulation and HIF-1α, VEGF, and/or MMP-9 downregulation. Furthermore, baicalein inhibition on retinal ischemia-induced MMP-9 upregulation seems to be “partly” associated with its antioxidation. Additionally, retinal ischemia, oxidative stress, and/or kainate excitotoxicity could be protected by resveratrol: “via MMP-9 and inducible nitric oxide synthetase (iNOS) downregulation, and heme oxygenase-1 (HO-1) upregulation,” S-allyl L-cysteine (SAC): “through iNOS, HIF-1α, VEGF inhibition and/or MMP-9 downregulation, and antiapoptosis,” Chi Ju Di Huang Wan: “by means of antiapoptosis, antioxidation, MMP-9 downregulation and p38 MAPK inhibition.

    ANALYSIS OF TRUNK ROTATION PATTERNS WHEN SWINGING AT DIFFERENT SPEEDS: A PILOT STUDY

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    As the trunk plays a vital role during the golf full swing, it is important to understand how body movements affect the golf swing. The purpose of this study was to determine how golfers increase club head speed through trunk rotation. Trunk rotation patterns were captured by 3D motion capture system at 250 Hz. To investigate the effective factors of increasing club head speed, we compared two situations, swing at normal club head speed and at accelerated club head speed, via the trunk rotation angles at three dimensions through six temporary events. The results showed that subtle differences between normal club head speed and accelerated club head speed. To increase club head speed, golfers might optimize the separation between shoulder and pelvic in the early downswing
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