197 research outputs found

    Construction of a [15]Annulenone-[15]annulenyl Ion Cycle

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    Previously, we have reported the synthesis of furanoid [15]annulenones and their protonated species. With the benefits of FT NMR spectroscopy, some of experiments have now been reinvestigated. The annulenone may undergo dynamic conformational changes to provide an interesting cycle, which can be driven by protonation- deprotonation sequence

    Construction of a [15]Annulenone-[15]annulenyl Ion Cycle

    Get PDF
    Previously, we have reported the synthesis of furanoid [15]annulenones and their protonated species. With the benefits of FT NMR spectroscopy, some of experiments have now been reinvestigated. The annulenone may undergo dynamic conformational changes to provide an interesting cycle, which can be driven by protonation- deprotonation sequence

    Septic Pulmonary Embolism Induced by Dental Infection

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    Dental infection can be an important source for septic pulmonary embolism (SPE), but only a few cases of SPE accompanying dental infection have been reported. The aim of this study was to characterize the clinical features of SPE induced by dental infection. Patients who fulfilled the diagnostic criteria described in the text were recruited in a retrospective fashion. All 9 patients were men, with a median age of 59 years (range:47 to 74 years). Eight patients had chest pain (88.9%), 5 had a preceding toothache (55.6%) and 3 had preceding gingival swelling (33.3%). Blood cultures obtained from 7 patients were negative. Periodontitis was found in all of the cases, periapical periodontitis in 5 cases, and gingival abscess in 3 cases. The median duration of hospitalization was 15 days, and symptoms were mild in some cases. In addition to antimicrobial therapy, tooth extraction was performed in 3 cases, tooth scaling in 6. SPE induced by dental infection has prominent clinical characteristics such as male preponderance, chest pain, preceding toothache, and mild clinical course

    Characterization of sensitivity and responses of a 2-element prototype wavefront sensor for millimeter-wave adaptive optics attached to the Nobeyama 45 m telescope

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    We report the results of the performance characterization of a prototype wavefront sensor for millimetric adaptive optics (MAO) installed on the Nobeyama 45 m radio telescope. MAO is a key component to realize a future large-aperture submillimeter telescope, such as Large Submillimeter Telescope (LST) or Atacama Large Aperture Submillimeter Telescope (AtLAST). The difficulty of MAO is, however, real-time sensing of wavefront deformation with ~10 um accuracy across the aperture. Our wavefront sensor operating at 20 GHz measures the radio path length between a certain position of the primary mirror surface to the focal point where a 20 GHz coherent receiver is placed. With the 2-element prototype, we sampled two positions on the primary mirror surface (at radii of 5 m and 16 m) at a sampling rate of 10 Hz. Then an excess path length (EPL) between the two positions was obtained by differentiating the two optical paths. A power spectral density of the EPL shows three components: a low-frequency drift (1/f^n), oscillations, and a white noise. A comparison of EPL measurements under a variety of wind conditions suggests that the former two are likely induced by the wind load on the telescope structure. The power of the white noise corresponds to a 1sigma statistical error of 8 um in EPL measurements. The 8 um r.m.s. is significant with respect to the mirror surface accuracy required by the LST and AtLAST (~20-40 um r.m.s.), which demonstrates that our technique is also useful for the future large-aperture submillimeter telescopes.Comment: 10 pages, 9 figures. Published in SPIE Pro

    Pair-density wave signature observed by x-ray scattering in La-based high-TcT_{\rm c} cuprates

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    Suggestive, but indirect evidence of the existence of pair-density wave (PDW) order in several high-TcT_{\rm c} cuprates has been reported. As this constitutes a new quantum phase of matter, it is important to {\it establish} its existence at least somewhere in the phase diagram. However, a direct correspondence between experiment and theory has remained elusive. Here, we report the observation of a theoretically predicted PDW {\it bulk} signature in two La-based cuprates, Sr-doped La1.875_{1.875}Ba0.125_{0.125}CuO4_4 and Fe-doped La1.87_{1.87}Sr0.13_{0.13}CuO4_4, through a comprehensive study that incorporates zero-magnetic field x-ray scattering, neutron scattering, and transport measurements. Specifically, we observe the emergence of so-called "1Q" order, which is to say subharmonic order associated with the charge-density wave (CDW) stripes, in a range of temperatures in which independent evidence suggests the co-existence of PDW long-range order and fluctuating uniform superconducting order. The subharmonic order is most pronounced around a half-integer ll-vector, where the CDW diffraction peak is also strongest. This is consistent with the theoretical proposal that the cancellation of the Josephson coupling ("layer-decoupling"), is a signature of PDW order and that it is commensurately locked to the density wave stripes that are known to alternate orientation between adjacent layers. Even if the PDW is not the "mother of all state", it is at least a close relative -- possibly a second cousin

    Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era

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    We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [O III] 88 μ\mum line and rest-frame 90 μ\mum dust continuum emission in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a spectroscopic redshift of z=8.3118±0.0003z = 8.3118 \pm 0.0003, making this object one of the furthest galaxies ever identified spectroscopically. The observed 850 μ\mum flux density of 137±26137 \pm 26 μ\muJy corresponds to a de-lensed total infrared (IR) luminosity of LIR=(1.7±0.3)×1011LL_{\rm IR} = (1.7 \pm 0.3) \times 10^{11} L_{\odot} if assuming a dust temperature of Tdust=50T_{\rm dust} = 50 K and an emissivity index of β=1.5\beta = 1.5, yielding a large dust mass of 4×106M4 \times 10^6 M_{\odot}. The ultraviolet-to-far IR spectral energy distribution modeling where the [O III] emissivity model is incorporated suggests the presence of a young (τage4\tau_{\rm age} \approx 4 Myr), star-forming (SFR 60M\approx 60 M_{\odot} yr1^{-1}), moderately metal-polluted (Z0.2ZZ \approx 0.2 Z_{\odot}) stellar component with a mass of Mstar=3×108MM_{\rm star} = 3 \times 10^8 M_{\odot}. An analytic dust mass evolution model with a single episode of star-formation does not reproduce the metallicity and dust mass in τage4\tau_{\rm age} \approx 4 Myr, suggesting a pre-existing evolved stellar component with Mstar3×109MM_{\rm star} \sim 3 \times 10^9 M_{\odot} and τage0.3\tau_{\rm age} \sim 0.3 Gyr as the origin of the dust mass.Comment: Accepted by ApJ. 18 pages, 10 figures, 5 table

    Submillimeter ALMA Observations of the Dense Gas in the Low-Luminosity Type-1 Active Nucleus of NGC 1097

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    We present the first 100 pc scale view of the dense molecular gas in the central ~ 1.3 kpc region of the type-1 Seyfert NGC 1097 traced by HCN (J=4-3) and HCO+ (J=4-3) lines afforded with ALMA band 7. This galaxy shows significant HCN enhancement with respect to HCO+ and CO in the low-J transitions, which seems to be a common characteristic in AGN environments. Using the ALMA data, we study the characteristics of the dense gas around this AGN and search for the mechanism of HCN enhancement. We find a high HCN (J=4-3) to HCO+ (J=4-3) line ratio in the nucleus. The upper limit of the brightness temperature ratio of HCN (v2=1^{1f}, J=4-3) to HCN (J=4-3) is 0.08, which indicates that IR pumping does not significantly affect the pure rotational population in this nucleus. We also find a higher HCN (J=4-3) to CS (J=7-6) line ratio in NGC 1097 than in starburst galaxies, which is more than 12.7 on the brightness temperature scale. Combined from similar observations from other galaxies, we tentatively suggest that this ratio appears to be higher in AGN-host galaxies than in pure starburst ones similar to the widely used HCN to HCO+ ratio. LTE and non-LTE modeling of the observed HCN and HCO+ lines using J=4-3 and 1-0 data from ALMA, and J=3-2 data from SMA, reveals a high HCN to HCO+ abundance ratio (5 < [HCN]/[HCO+] < 20: non-LTE analysis) in the nucleus, and that the high-J lines (J=4-3 and 3-2) are emitted from dense (10^{4.5} < n_H2 [/cc] < 10^6), hot (70 < Tkin [K] < 550) regions. Finally we propose that the high temperature chemistry is more plausible to explain the observed enhanced HCN emission in NGC 1097 than the pure gas phase PDR/XDR chemistry.Comment: 28 pages, 17 figures, 10 tables. Accepted to PAS

    Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) VIII. A less biased view of the early co-evolution of black holes and host galaxies

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    We present ALMA [CII] line and far-infrared (FIR) continuum observations of three z>6z > 6 low-luminosity quasars (M1450>25M_{\rm 1450} > -25) discovered by our Subaru Hyper Suprime-Cam (HSC) survey. The [CII] line was detected in all three targets with luminosities of (2.49.5)×108 L(2.4 - 9.5) \times 10^8~L_\odot, about one order of magnitude smaller than optically luminous (M145025M_{\rm 1450} \lesssim -25) quasars. The FIR continuum luminosities range from <9×1010 L< 9 \times 10^{10}~L_\odot (3σ\sigma limit) to 2×1012 L\sim 2 \times 10^{12}~L_\odot, indicating a wide range in star formation rates in these galaxies. Most of the HSC quasars studied thus far show [CII]/FIR luminosity ratios similar to local star-forming galaxies. Using the [CII]-based dynamical mass (MdynM_{\rm dyn}) as a surrogate for bulge stellar mass (MbulgeM_{\rm bulge}), we find that a significant fraction of low-luminosity quasars are located on or even below the local MBHMbulgeM_{\rm BH} - M_{\rm bulge} relation, particularly at the massive end of the galaxy mass distribution. In contrast, previous studies of optically luminous quasars have found that black holes are overmassive relative to the local relation. Given the low luminosities of our targets, we are exploring the nature of the early co-evolution of supermassive black holes and their hosts in a less biased way. Almost all of the quasars presented in this work are growing their black hole mass at much higher pace at z6z \sim 6 than the parallel growth model, in which supermassive black holes and their hosts grow simultaneously to match the local MBHMbulgeM_{\rm BH} - M_{\rm bulge} relation at all redshifts. As the low-luminosity quasars appear to realize the local co-evolutionary relation even at z6z \sim 6, they should have experienced vigorous starbursts prior to the currently observed quasar phase to catch up with the relation.Comment: 19 pages, 11 figures, 4 tables. Accepted for publication in Publications of the Astronomical Society of Japan (PASJ
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