147 research outputs found

    C‐Glycosyltransferases catalyzing the formation of di‐C‐glucosyl flavonoids in citrus plants

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    Citrus plants accumulate many kinds of flavonoids, including di‐C‐glucosyl flavonoids, which have attracted considerable attention due to their health benefits. However, the biosynthesis of di‐C‐glucosyl flavonoids has not been elucidated at the molecular level. Here, we identified the C‐glycosyltransferases (CGTs) FcCGT (UGT708G1) and CuCGT (UGT708G2) as the primary enzymes involved in the biosynthesis of di‐C‐glucosyl flavonoids in the citrus plants kumquat (Fortunella crassifolia) and satsuma mandarin (Citrus unshiu), respectively. The amino acid sequences of these CGTs were 98% identical, indicating that CGT genes are highly conserved in the citrus family. The recombinant enzymes FcCGT and CuCGT utilized 2‐hydroxyflavanones, dihydrochalcone, and their mono‐C‐glucosides as sugar acceptors and produced corresponding di‐C‐glucosides. The Km and kcat values of FcCGT toward phloretin were <0.5 μm and 12.0 sec−1, and those toward nothofagin (3ʹ‐C‐glucosylphloretin) were 14.4 μm and 5.3 sec−1, respectively; these values are comparable with those of other glycosyltransferases reported to date. Transcripts of both CGT genes were found to concentrate in various plant organs, and particularly in leaves. Our results suggest that di‐C‐glucosyl flavonoid biosynthesis proceeds via a single enzyme using either 2‐hydroxyflavanones or phloretin as a substrate in citrus plants. In addition, Escherichia coli cells expressing CGT genes were found to be capable of producing di‐C‐glucosyl flavonoids, which is promising for commercial production of these valuable compounds.ArticlePlant Journal.91(2):187-198(2017)journal articl

    On the lack of strong O-line excess in the Coma cluster outskirts from Suzaku

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    About half of the baryons in the local Universe are thought to reside in the so-called warm-hot intergalactic medium (WHIM) at temperatures of 0.1-10 million K. Thermal soft excess emission in the spectrum of some cluster outskirts that contains OVII and/or OVIII emission lines is regarded as evidence of the WHIM, although the origin of the lines is controversial due to strong Galactic and solar system foreground emission. We observed the Coma-11 field, where the most prominent thermal soft excess has ever been reported, with Suzaku XIS in order to make clear the origin of the excess. We did not confirm OVII or OVIII excess emission. The OVII and OVIII intensity in Coma-11 is more than 5 sigma below that reported before and we obtained 2 sigma upper limits of 2.8 and 2.9 photons cm^-2 s^-1 sr^-1 for OVII and OVIII, respectively. The intensities are consistent with those in another field (Coma-7) that we measured, and with other measurements in the Coma outskirts (Coma-7 and X Com fields with XMM-Newton). We did not confirm the spatial variation within Coma outskirts. The strong oxygen emission lines previously reported are likely due to solar wind charge exchange.Comment: 5 pages, 3 figures. Accepted for publication in Ap

    Development of a large area gas photomultiplier with GEM/μ\muPIC

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    We are developing a new photon detector with micro pattern gaseous detectors. A semitransparent CsI photocathode is combined with 10cm×\times10cm GEM/μ\muPIC for the first prototype which is aimed for the large liquid Xe detectors. Using Ar+C2_2H6_6 (10%) gas, we achieved the gas gain of 10510^5 which is enough to detect single photoelectron. We, then, irradiated UV photons from a newly developed solid scintillator, LaF3_3(Nd), to the detector and successfully detected single photoelectron.Comment: Poster presentation at ICHEP08 Philadelphia, USA, July 2008. 3 pages, LaTeX, 4 eps figure

    Survey of imaging dose in HDR brachytherapy

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    Institutional imaging protocols for the verification of brachytherapy applicator placements were investigated in a survey study of domestic radiotherapy institutions. The survey form designed by a free on-line survey system was distributed via the mailing-list system of the Japanese Society for Radiation Oncology. Survey data of 75 institutions between August 2019 and October 2019 were collected. The imaging modalities used were dependent on resources available to the institutions. The displacement of a brachytherapy applicator results in significant dosimetric impact. It is essential to verify applicator placements using imaging modalities before treatment. Various imaging modalities used in institutions included a computed tomography (CT) scanner, an angiography X-ray system, a multi-purpose X-ray system and a radiotherapy simulator. The median total exposure time in overall treatment sessions was ≤75 s for gynecological and prostate cancers. Some institutions used fluoroscopy to monitor the brachytherapy source movement. Institutional countermeasures for reducing unwanted imaging dose included minimizing the image area, changing the imaging orientation, reducing the imaging frequency and optimizing the imaging conditions. It is worth noting that half of the institutions did not confirm imaging dose regularly. This study reported on the usage of imaging modalities for brachytherapy in Japan. More caution should be applied with interstitial brachytherapy with many catheters that can lead to potentially substantial increments in imaging doses for monitoring the actual brachytherapy source using fluoroscopy. It is necessary to share imaging techniques, standardize imaging protocols and quality assurance/quality control among institutions, and imaging dose guidelines for optimization of imaging doses delivered in radiotherapy should be developed

    Cyclic Naphthalene Diimide with a Ferrocene Moiety as a Redox-Active Tetraplex-DNA Ligand

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    Cyclic naphthalene diimides (cNDIs), with a ferrocene moiety (cFNDs) and different linker lengths between the ferrocene and cNDI moieties, were designed and synthesized as redox‐active, tetraplex‐DNA ligands. Intramolecular stacking was observed between ferrocene and the NDI planes, which could affect the binding properties for G‐quadruplexes. Interestingly, the circular dichroism spectrum of one of these compounds clearly shows new Cotton effects around 320–380 and 240 nm, which can be considered a direct evidence of intramolecular stacking of ferrocene and the NDI. Regarding recognition of hybrid G‐quadruplexes, the less rigid structures (longer linkers) show higher binding affinity (106 M−1 order of magnitude). All new compounds show higher selectivity for G4 during electrochemical detection than noncyclic FND derivatives, which further identifies the redox‐active potentiality of the cFNDs. Two of the three compounds tested even show preferential inhibition of cell growth in cancer cells over normal cells in a low concentration range, highlighting the potential for bioapplications of these cFNDs

    Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XIII. Large-scale Feedback and Star Formation in a Low-luminosity Quasar at z = 7.07 on the Local Black Hole to Host Mass Relation

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    We present Atacama Large Millimeter/submillimeter Array [C II] 158 μm line and underlying far-infrared (FIR) continuum emission observations (0 70 × 0 56 resolution) toward HSC J124353.93+010038.5 (J1243+0100) at z = 7.07, the only low-luminosity (M1450 > −25 mag) quasar currently known at z > 7. The FIR continuum is bright (1.52 mJy) and resolved with a total luminosity of LFIR = 3.5 × 1012 Le. The spatially extended component is responsible for ∼40% of the emission. The area-integrated [C II] spectrum shows a broad wing (FWHM = 997 km s−1 , L[C II] = 1.2 × 109 Le), as well as a bright core (FWHM = 235 km s−1 , L[C II] = 1.9 × 109 Le). This wing is the first detection of a galactic-scale quasar-driven outflow (atomic outflow rate >447 Me yr−1 ) at z > 7. The estimated large mass-loading factor of the total outflow (e.g., 9 relative to the [C II]-based star formation rate) suggests that this outflow will soon quench the star formation of the host. The core gas dynamics are governed by rotation, with a rotation curve suggestive of a compact bulge (∼3.3 × 1010 Me), although it is not yet spatially resolved. Finally, we found that J1243+0100 has a black hole mass–to–dynamical mass (and –to–bulge mass) ratio of ∼0.4% (∼1%), consistent with the local value within the uncertainties. Our results therefore suggest that the black hole–host coevolution relation is already in place at z ∼ 7 for this object

    Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures : the Denture Adhesive Guideline trial : study protocol for a randomized controlled trial

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    Background: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. Methods: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. Discussion: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries
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