513 research outputs found

    Pulsed UCN production using a Doppler shifter at J-PARC

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    We have constructed a Doppler-shifter-type pulsed ultra-cold neutron (UCN) source at the Materials and Life Science Experiment Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). Very-cold neutrons (VCNs) with 136-m/s\mathrm{m/s} velocity in a neutron beam supplied by a pulsed neutron source are decelerated by reflection on a m=10 wide-band multilayer mirror, yielding pulsed UCN. The mirror is fixed to the tip of a 2,000-rpm rotating arm moving with 68-m/s\mathrm{m/s} velocity in the same direction as the VCN. The repetition frequency of the pulsed UCN is 8.33Ā Hz8.33~\mathrm{Hz} and the time width of the pulse at production is 4.4Ā ms4.4~\mathrm{ms}. In order to increase the UCN flux, a supermirror guide, wide-band monochromatic mirrors, focus guides, and a UCN extraction guide have been newly installed or improved. The 1Ā MW1~\mathrm{MW}-equivalent count rate of the output neutrons with longitudinal wavelengths longer than 58Ā nm58~\mathrm{nm} is 1.6Ɨ102Ā cps1.6 \times 10^{2}~\mathrm{cps}, while that of the true UCNs is 80Ā cps80~\mathrm{cps}. The spatial density at production is 1.4Ā UCN/cm31.4~\mathrm{UCN/cm^{3}}. This new UCN source enables us to research and develop apparatuses necessary for the investigation of the neutron electric dipole moment (nEDM).Comment: 32 pages, 15 fugures. A grammatical error was fixe

    Pulsed neutron time-dependent intensity modulation for quasi-elastic neutron scattering spectroscopy

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    We propose a basic formula and demonstration for a high-resolution quasi-elastic neutron scattering (QENS) by combining the time-of-flight (TOF) method with Modulation of Intensity by Zero Effort (MIEZE) type neutron spin echo spectroscopy. The MIEZE technique has the potential to develop a unique approach to study on slow dynamics of condensed matter; however, the energy resolution is limited owing to the hypersensitivity of the MIEZE signal contrast to the echo condition, which is strongly affected by the alignment of the instruments and the sample. The narrow allowance of the optimal alignment is a major obstacle to the wide use of this technique. Combining the TOF method with MIEZE (TOF-MIEZE), the hypersensitivity of MIEZE signals is significantly alleviated with a short pulsed beam. This robustness is very useful to optimize experimental alignments and enables accurate measurements of QENS. The experimental results demonstrate the characteristic of the TOF-MIEZE technique and are well described by the formula presented in this study

    Towards a high-resolution TOF-MIEZE spectrometer with very cold neutrons

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    We report the first experimental test of TOF-MIEZE technique using very cold neutrons (VCNs) towards high-resolution quasi-elastic neutron scattering spectroscopy. TOF-MIEZE is a type of neutron resonance spin echo spectroscopy with a combination of the time-of-flight (TOF) method and modulation of intensity by zero effort (MIEZE). A compact MIEZE instrument was constructed at the VCN beam port at the High Flux Reactor at the Institut Laue Langevin. By accumulating individual oscillations of raw data, we observed a TOF-MIEZE signal with an effective frequency of 50 kHz in a wavelength band of 4ā€“6 nm. The signal contrasts were 0.59 Ā± 0.04 and 0.29 Ā± 0.03 for wavelengths of 4 nm and 6 nm, respectively. The Fourier time was estimated to be 70 ns with 6 nm VCNs in the experimental set-up

    Effects of bronchodilators on dynamic hyperinflation following hyperventilation in patients with COPD

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    ā€˜The definitive version is available at www.blackwell-synergy.com '.ArticleRespirology. 12(1): 93-99 (2007)journal articl

    Oxygen ultra-fine bubbles water administration prevents bone loss of glucocorticoid-induced osteoporosis in mice by suppressing osteoclast differentiation

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    Summary: Oxygen ultra-fine bubbles (OUB) saline injection prevents bone loss of glucocorti\coid-induced osteoporosis in mice, and OUB inhibit osteoclastogenesis via RANK-TRAF6-c-Fos-NFATc1 signaling and RANK-p38 MAPK signaling in vitro. Introduction: Ultra-fine bubbles (<200Ā nm in diameter) have several unique properties, and they are tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUB) on glucocorticoid-induced osteoporosis (GIO) model mice. Methods: Prednisolone (PSL, 5Ā mg) was subcutaneously inserted in 6-month-old male C57BL/6J mice, and 200Ā Ī¼l of saline, OUB-diluted saline, or nitrogen ultra-fine bubbles (NUB)-diluted saline was intraperitoneally injected three times per week for 8Ā weeks the day after operations. Mice were divided into four groups; (1) control, sham-operationĀ +Ā saline; (2) GIO, PSLĀ +Ā saline; (3) GIOĀ +Ā OUB, PSLĀ +Ā OUB saline; (4) GIOĀ +Ā NUB, PSLĀ +Ā NUB saline. The effects of OUB on osteoblasts and osteoclasts were examined by serially diluted OUB medium in vitro. Results: Bone mass was significantly decreased in GIO [bone volume/total volume (%): control vs. GIO 12.6 vs. 7.9; pĀ <Ā 0.01] while significantly preserved in GIOĀ +Ā OUB (GIO vs. GIOĀ +Ā OUB 7.9 vs. 12.9; pĀ <Ā 0.05). In addition, tartrate-resistant acid phosphatase (TRAP)-positive cells in the distal femur [mean osteoclasts number/bone surface (mmāˆ’1)] was significantly increased in GIO (control vs. GIO 6.8 vs. 11.6; pĀ <Ā 0.01) while suppressed in GIOĀ +Ā OUB (GIO vs. GIOĀ +Ā OUB 11.6 vs. 7.5; pĀ <Ā 0.01). NUB did not affect these parameters. In vitro experiments revealed that OUB significantly inhibited osteoclastogenesis by inhibiting RANK-TRAF6-c-Fos-NFATc1 signaling, RANK-p38 MAPK signaling, and TRAP/Cathepsin K/DC-STAMP mRNA expression in a concentration-dependent manner. OUB did not affect osteoblastogenesis in vitro. Conclusions: OUB prevent bone loss in GIO mice by inhibiting osteoclastogenesis.This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Natureā€™s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00198-016-3830-1Noguchi T., Ebina K., Hirao M., et al. Oxygen ultra-fine bubbles water administration prevents bone loss of glucocorticoid-induced osteoporosis in mice by suppressing osteoclast differentiation. Osteoporosis International 28, 1063 (2017); https://doi.org/10.1007/s00198-016-3830-1
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