603 research outputs found

    An ytterbium quantum gas microscope with narrow-line laser cooling

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    We demonstrate site-resolved imaging of individual bosonic 174Yb^{174}\mathrm{Yb} atoms in a Hubbard-regime two-dimensional optical lattice with a short lattice constant of 266 nm. To suppress the heating by probe light with the 1S0^1S_0-1P1^1P_1 transition of the wavelength λ\lambda = 399 nm for high-resolution imaging and preserve atoms at the same lattice sites during the fluorescence imaging, we simultaneously cool atoms by additionally applying narrow-line optical molasses with the 1S0^1S_0-3P1^3P_1 transition of the wavelength λ\lambda = 556 nm. We achieve a low temperature of $T = 7.4(1.3)\ \mu\mathrm{K}$, corresponding to a mean oscillation quantum number along the horizontal axes of 0.22(4) during imaging process. We detect on average 200 fluorescence photons from a single atom within 400 ms exposure time, and estimate the detection fidelity of 87(2)%. The realization of a quantum gas microscope with enough fidelity for Yb atoms in a Hubbard-regime optical lattice opens up the possibilities for studying various kinds of quantum many-body systems such as Bose and Fermi gases, and their mixtures, and also long-range-interacting systems such as Rydberg states.Comment: 14 pages, 6 figure

    Geographical and Orbital Information Based Mobility Management to Overcome Last-Hop Ambiguity over IP/LEO Satellite Networks

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    科研費報告書収録論文(課題番号:17500030/研究代表者:加藤寧/インターネットと高親和性を有する次世代低軌道衛星ネットワークに関する基盤研究

    An improved content search engine. Usage of network configuration information

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    科研費報告書収録論文(課題番号:09680388・基盤研究(C)(2)・H9~H10/研究代表者:根元, 義章/情報フィルタリングを用いた大規模情報ネットワークのリアルタイム障害検出方式

    極低温異核フェッシュバッハ分子の研究

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    学位の種別: 課程博士審査委員会委員 : (主査)東京大学准教授 井上 慎, 東京大学教授 上田 正仁, 東京大学教授 香取 秀俊, 東京大学教授 小芦 雅斗, 東京大学特任教授 三尾 典克University of Tokyo(東京大学

    Sirt1 expression is associated with CD31 expression in blood cells from patients with chronic obstructive pulmonary disease

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    Background: Cigarette smoke induced oxidative stress has been shown to reduce silent information regulator 1 (Sirt1) levels in lung tissue from smokers and patients with COPD patients. Sirt1 is known to inhibit endothelial senescence and may play a protective role in vascular cells. Endothelial progenitor cells (EPCs) are mobilized into circulation under various pathophysiological conditions, and are thought to play an important role in tissue repair in chronic obstructive lung disease (COPD). Therefore, Sirt1 and EPC-associated mRNAs were measured in blood samples from patients with COPD and from cultured CD34+ progenitor cells to examine whether these genes are associated with COPD development. Methods: This study included 358 patients with a smoking history of more than 10 pack-years. RNA was extracted from blood samples and from CD34+ progenitor cells treated with cigarette smoke extract (CSE), followed by assessment of CD31, CD34, Sirt1 mRNA, miR-34a, and miR-126-3p expression by real-time RT-PCR. Results: The expression of CD31, CD34, Sirt1 mRNAs, and miR-126-3p decreased and that of miR-34a increased in moderate COPD compared with that in control smokers. However, no significant differences in these genes were observed in blood cells from patients with severe COPD compared with those in control smokers. CSE significantly decreased Sirt1 and increased miR-34a expression in cultured progenitor cells. Conclusion: Sirt1 expression in blood cells from patients with COPD could be a biomarker for disease stability in patients with moderate COPD. MiR-34a may participate in apoptosis and/or senescence of EPCs in smokers. Decreased expression of CD31, CD34, and miR-126-3p potentially represents decreased numbers of EPCs in blood cell from patients with COPD
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