263 research outputs found

    Ferroelectric Instability and Dimensionality in Bi-Layered Perovskites and Thin Films

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    The dielectric and thermal properties of Bi (bismuth)-layered perovskite SrBi2Ta2O9 (SBT) are discussed in comparison with ferroelectric thin BaTiO3 films. Although these two perovskites exhibit quite a different nature, the dielectric properties of BaTiO3 thin film are similar to those in bulk SBT. The dielectric properties and pseudo-two-dimensional structure between SBT and thin film suggest that the bulk layered ferroelectric SBT is a good model of ultra-thin ferroelectric film with two perovskite layers, free from any misfit lattice strain with substrate and surface charge at the interface with electrodes. Based on the mechanism of ferroelectric phase transition of SBT, it seems plausible that the ferroelectric interaction is still prominent but shows a crossover from ferroelectric to antiferroelectric interaction in perovskite ultra-thin films along the tetragonal axis

    ACCURACY IN DETERMINING KINETIC PARAMETERS WITH FORCE PLATES EMBEDDED UNDER SOIL-FILLED BASEBALL MOUND

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    We developed a force measurement system embedded in a soil-filled mound for measuring ground reaction forces (GRF) acting on baseball pitchers and examined the accuracy of determining the point of force application (PFA) and kinetic parameters computed from GRF. Three 1.0 x 0.9 m2 force platforms were placed on the concrete foundation of an indoor sports facility and three bays were fixed onto the aluminum plates of the force plateorms. In each tray, clay-blocks were laid tightly and a mixture of red sand and volcanic-ash was used to make a smooth surface layer. The mean absolute error was 6.0 f 4.0 mm in determining PFA, less than 15.5 Ns (5% of the true value) in determining linear impulse. These results suggest that the present method is valid for measuring the PFA and GRF acting on the pitcher's legs for analyzing kinetics of pitching performances

    CT画像を用いて算出したHip Structural Analysis(HSA)指標の検討

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    骨粗鬆症に伴う脆弱性骨折を起こすか否かは,骨量,骨構造,骨の石灰化,ダメージの蓄積および骨代謝などに依存するとされているが,近年,骨量測定に臨床で広く用いられているDXA装置に大腿骨近位部の構造力学的解析が可能なHip Structural Analysis (HSA) のプログラムが組み込まれ,骨強度の評価に用いられている.そこで我々は,CT画像からHSA指標の算出が可能か否か,また,その手法による指標の計算精度について,DXA装置で得られた指標と比較することによって検討した.その結果,CT画像からHSA指標の算出は可能であったが,その計算精度に若干の問題があり,撮影時の整位および計算位置の解剖学的なズレ等を補正する必要があることがわかった

    Nanoscale corrosion behavior of polycrystalline copper fine wires in dilute NaCl solution investigated by in-situ atomic force microscopy

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    In this study, nanoscale corrosion behavior of copper fine wires in dilute NaCl solution is studied by atomic force microscopy and electron backscatter diffraction. The dissolution rate of grains constituting the wires strongly depends on their crystallographic orientation. In pure water, the dissolution rate increases in the order of (111) < (001) < (110). Addition of Cl- dramatically increases the dissolution rate of the (111) surface to alter the order to (110) ≈ (001) ≈ (111) at 0.1 mM. These results show that the crystallographic orientation dependence is significantly changed by a slight increase of Cl- concentration in dilute solution. © 2016 Elsevier Ltd.Embargo Period 24 month

    Serial Cerebral Perfusion Imaging in a Case with Herpes Simplex Encephalitis

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    To evaluate cerebral blood flow, single photon emission computed tomographies (SPECTs) were serially performed in a case with herpes simplex encephalitis (HSE). Increased accumulation of N-ispropyl-I-123-p-iodoamphetamine (I-123-IMP) and Tc - 99m - hexamethylpropyleneamine oxime (Tc - 99m - HM - PAO) were noticed in the acute phase, and continued for seven weeks after the onset of the disease. In the third week, regional cerebral blood flow (rCBF) was estimated with I-123-IMP SPECT, and rCBF showed a high value in the affected temporal and occipital lobes of 60 to 70 ml/100 g/min (normal value; 40-50 ml/100 g/min), reflecting high accumulation of the tracer. After the twelfth week, when chinical symptoms and laboratory data had improved, the increased accumulation of these tracers was converted to a decreased accumulation

    Disturbance of cerebellar synaptic maturation in mutant mice lacking BSRPs, a novel brain-specific receptor-like protein family

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    AbstractBy DNA cloning, we have identified the BSRP (brain-specific receptor-like proteins) family of three members in mammalian genomes. BSRPs were predominantly expressed in the soma and dendrites of neurons and localized in the endoplasmic reticulum (ER). Expression levels of BSRPs seemed to fluctuate greatly during postnatal cerebellar maturation. Triple-knockout mice lacking BSRP members exhibited motor discoordination, and Purkinje cells (PCs) were often innervated by multiple climbing fibers with different neuronal origins in the mutant cerebellum. Moreover, the phosphorylation levels of protein kinase Cα (PKCα) were significantly downregulated in the mutant cerebellum. Because cerebellar maturation and plasticity require metabotropic glutamate receptor signaling and resulting PKC activation, BSRPs are likely involved in ER functions supporting PKCα activation in PCs
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