175 research outputs found

    Heparinとの可逆的な結合は抗菌活性およびLPS中和能を減弱することなく,高濃度LL37の細胞障害性を改善する

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    広島大学(Hiroshima University)博士(歯学)Doctor of Philosophy in Dental Sciencedoctora

    From photoelectron detachment spectra of BrHBr−, BrDBr− and IHI−, IDI− to vibrational bonding of BrMuBr and IMuI

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    Photoelectron detachment XLX−(0000) + hν → XLX(vib) + e − + KER (X = Br or I, L = H or D) at sufficiently low temperatures photoionizes linear dihalogen anions XLX− in the vibrational ground state (v 1 v 2 l v 3 = 0000) and prepares the neutral radicals XLX(vib) in vibrational states (vib). At the same time, part of the photon energy (hν) is converted into kinetic energy release (KER) of the electron [R. B. Metz, S. E. Bradforth, and D. M. Neumark, Adv. Chem. Phys. 81, 1 (1992)]. The process may be described approximately in terms of a Franck-Condon type transfer of the vibrational wavefunction representing XLX−(0000) from the domain close to the minimum of its potential energy surface (PES) to the domain close to the linear transition state of the PES of the neutral XLX. As a consequence, prominent peaks of the photoelectron detachment spectra (pds) correlate with the vibrational energies E XLX,vib of states XLX(vib) which are centered at linear transition state. The corresponding vibrational quantum numbers may be labeled vib = (v 1 v 2 l v 3) = (000 v 3). Accordingly, the related most prominent peaks in the pds are labeled v 3. We construct a model PES which mimics the “true” PES in the domain of transition state such that it supports vibrational states with energies E XLX,pds,000v3 close to the peaks of the pds labeled v 3 = 0, 2, and 4. Subsequently, the same model PES is also used to calculate approximate values of the energies E XMuX,0000 of the isotopomers XMuX(0000). For the heavy isotopomers XHX and XDX, it turns out that all energies E XLX,000 v 3 are above the threshold for dissociation, which means that all heavy XLX(000 v 3) with wavefunctions centered at the transition state are unstable resonances with finite lifetimes. Turning the table, bound states of the heavy XLX are van der Waals (vdW) bonded. In contrast, the energies E XMuX,0000 of the light isotopomers XMuX(0000) are below the threshold for dissociation, with wavefunctions centered at the transition state. This means that XMuX(0000) are vibrationally bonded. This implies a fundamental change of the nature of chemical bonding, from vdW bonding of the heavy XHX, XDX to vibrational bonding of XMuX. For BrMuBr, the present results derived from experimental pds of BrHBr− and BrDBr− confirm the recent discovery of vibrational bonding based on quantum chemical ab initio calculations [D. G. Fleming, J. Manz, K. Sato, and T. Takayanagi, Angew. Chem., Int. Ed. 53, 13706 (2014)]. The extension from BrLBr to ILI means the discovery of a new example of vibrational bonding. These empirical results for the vibrational bonding of IMuI, derived from the photoelectron spectra of IHI− and IDI−, are supported by ab initio simulations of the spectra and of the wavefunction representing vibrational bonding of IMuI

    Time-Domain Universal Linear-Optical Operations for Universal Quantum Information Processing

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    We demonstrate universal and programmable three-mode linear optical operations in the time domain by realizing a scalable dual-loop optical circuit suitable for universal quantum information processing (QIP). The programmability, validity, and deterministic operation of our circuit are demonstrated by performing nine different three-mode operations on squeezed-state pulses, fully characterizing the outputs with variable measurements, and confirming their entanglement. Our circuit can be scaled up just by making the outer loop longer and also extended to universal quantum computers by incorporating feedforward systems. Thus, our work paves the way to large-scale universal optical QIP

    Raman Scattering Investigation of Structural Transition in Ca5Ir3O12

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    We report a study of the second-order phase transition at 105 K in the geometrically frustrated iridate Ca5Ir3O12 using a Raman scattering method. The Raman scattering spectra of a single crystal were measured from 4 K to room temperature. Ab initio phonon calculations that consider the spin–orbit interaction were also conducted and compared with the experimental spectra. Agreement between the theoretical and experimental results at room temperature is reasonably good. At room temperature, 6A\u271+9E\u27+5E\u27\u27 were assigned among the Raman active modes, 6A\u271+13E\u27+6E\u27\u27, based on the reported P6¯2m crystal structure. Below Ts, 23 additional peaks were observed, suggesting the appearance of a superlattice structure. The polarization dependence of Raman spectra below Ts indicates the existence of 6¯ symmetry. We observed at least one additional mode as a broad weak-intensity peak at temperatures higher than Ts. This suggests possible local distortion around the Ir ions, which would be expected for Ir ions with mixed valence states

    High-temperature Fluidized Receiver for Concentrated Solar Radiation by a Beam-down Reflector System

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    AbstractThis study proposes a novel fluidized receiver for absorbing concentrated solar light at high temperatures. Previously, a tubular receiver and a volumetric receiver were developed to make high-temperature air for a solar gas turbine system. The aim was to combine these elements with a tower reflector; however, it was challenging to install these heavy receivers on the top of the tower. Currently, a fluidized receiver prototype is tested by a 3 kWh solar simulator in preparation for a field test at the Miyazaki beam-down reflector system. The fluid dynamics of the prototype receiver is numerically investigated. The currently treated receiver is an inner-circulating fluidized bed spouted by concentric gas streams with high and low velocities in the center and outer annulus, respectively. The draft tube is submerged in the particles to organize particle circulation. Concentrated light irradiates the particles through a quartz window at the top of the receiver container. Such a fluidized bed was first adopted by Kodama et al. for thermochemical reactions; however, it is currently pursued for its potential as a high-temperature receiver aimed at concentrated solar power generation. Experiments of the prototype receiver (inner diameter = 45mm) demonstrated that the inner particles are heated to a temperature greater than 900°C and that an increase of the central gas velocity removes the excess temperature near the particle bed surface. A numerical computation suggests that the large-scale circulation of particles leads to the activation of thermal mixing. The currently proposed receiver is thus expected to attenuate re-radiation losses likely to occur in a conventional volumetric porous receiver. The scale-up of the receiver is being considered by the numerical computation for a field test in the Miyazaki 100 kWh beam-down reflector system

    Study on the Development of a New Device with Dual Cameras for Evaluating Expiratory Nasal Flow

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    [Background] Use of the Glatzel mirror for measuring expiratory nasal flow in preschool children has the disadvantage of vagueness, and the mirror may induce fear and inhibition of interest in those children. In response to these limitations, we developed a new device with dual cameras for measuring expiratory nasal flow in 2 to 6 year old children. The aim of this study is to compare the Glatzel mirror and the new device, in terms of accurate assessment of expiratory nasal flow, children’s feelings, and correlation to each child’s profile. [Methods] This study evaluated 20 cleft lip and palate patients and 21 healthy children aged between 2 and 6 (under 7) years. After consent was granted, a 4-week screening period was undertaken followed by inspection at weeks 8, 16, 24, and 32. Each inspection was conducted while the children were asked to pronounce various sounds and comprised three stages: i) use of the Glatzel mirror, ii) subjective visual assessment using the new device, and iii) image recording by dual cameras of the new device. Questionnaires for the new device were administered at the initial and final inspections. To contrast the results between the Glatzel mirror and the new device, the numbers that indicated values of subjective visual assessment and camera assessment greater than the assessment values of the Glatzel mirror were compared. For measuring the children’s responses to the new device compared with those to the Glatzel mirror, the answers to the questionnaires were compared. For the comparison of the children’s profiles (age and sex) and feelings, the numbers of subjects who could use the new device were measured. [Results] The camera assessment of the new device indicated significantly greater values than that of the Glatzel mirror (P < 0.05). The feelings of the subjects to the new device mostly improved as the study progressed. Subjects aged 3 years and older were generally able to use the new device from the initial inspection. For both sexes, as the inspection progressed, the number occasions of successful use increased. [Conclusion] This study demonstrated the superiority of the new device with dual cameras to the Glatzel mirror in terms of functionality and attitude of children

    14-Cmethionine uptake as a potential marker of inflammatory processes after myocardial ischemia and reperfusion

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    A relationship between L-[methyl-11C]methionine (11C-methionine) uptake and angiogenesis has been suggested in gliomas. However, methionine uptake in myocardial ischemia and reperfusion has received little attention. We investigated the serial changes and mechanisms of 14-Cmethionine uptake in a rat model of myocardial ischemia and reperfusion. Methods: The left coronary artery was occluded for 30 min, followed by reperfusion for 1-28 d. At the time of the study, 14-Cmethionine (0.74 MBq) and 201Tl (14.8 MBq) were injected intravenously at 20 and 10 min before sacrifice, respectively. One minute before sacrifice, the left coronary artery was reoccluded, and 99mTc-hexakis-2-methoxyisobutylisonitrile (150-180 MBq) was injected to verify the area at risk. Histologic sections of the heart were immunohistochemically analyzed using anti-CD68, anti-smooth-muscle a-actin (SMA), and antitroponin I and compared with the autoradiography findings. Results: Both 14Cmethionine (uptake ratio, 0.71 ± 0.13) and 201Tl uptake were reduced in the area at risk at 1 d after reperfusion. However, 3 d after reperfusion, an increased 14-Cmethionine uptake (1.79 ± 0.23) was observed corresponding to the area of still-reduced 201Tl uptake, and the 14-Cmethionine uptake gradually declined until 28 d. The increased 14-Cmethionine uptake area at 3 and 7 d corresponded well to the macrophage infiltrations demonstrated by positive CD68 staining. Anti-SMA staining appeared at 7 d, after which CD68 staining was gradually replaced by the SMA staining, suggesting that methionine uptake in the early phase after ischemia and reperfusion might reflect inflammatory activity. Conclusion: 14-Cmethionine accumulated in the infarcted area, and its uptake corresponded closely to macrophage infiltration at 3-7 d after reperfusion. Methionine imaging may be useful for inflammatory imaging early after myocardial infarction. COPYRIGHT © 2013 by the Society of Nuclear Medicine and Molecular Imaging, Inc

    Promotion of allergic immune responses by intranasally-administrated nanosilica particles in mice

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    With the increase in use of nanomaterials, there is growing concern regarding their potential health risks. However, few studies have assessed the role of the different physical characteristics of nanomaterials in allergic responses. Here, we examined whether intranasally administered silica particles of various sizes have the capacity to promote allergic immune responses in mice. We used nanosilica particles with diameters of 30 or 70 nm (nSP30 or nSP70, respectively), and conventional micro-sized silica particles with diameters of 300 or 1000 nm (nSP300 or mSP1000, respectively). Mice were intranasally exposed to ovalbumin (OVA) plus each silica particle, and the levels of OVA-specific antibodies (Abs) in the plasma were determined. Intranasal exposure to OVA plus smaller nanosilica particles tended to induce a higher level of OVA-specific immunoglobulin (Ig) E, IgG and IgG1 Abs than did exposure to OVA plus larger silica particles. Splenocytes from mice exposed to OVA plus nSP30 secreted higher levels of Th2-type cytokines than mice exposed to OVA alone. Taken together, these results indicate that nanosilica particles can induce allergen-specific Th2-type allergic immune responses in vivo. This study provides the foundations for the establishment of safe and effective forms of nanosilica particles

    Recent Progress of Flower Colour Modification by Biotechnology

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    Genetically-modified, colour-altered varieties of the important cut-flower crop carnation have now been commercially available for nearly ten years. In this review we describe the manipulation of the anthocyanin biosynthesis pathway that has lead to the development of these varieties and how similar manipulations have been successfully applied to both pot plants and another cut-flower species, the rose. From this experience it is clear that down- and up-regulation of the flavonoid and anthocyanin pathway is both possible and predictable. The major commercial benefit of the application of this technology has so far been the development of novel flower colours through the development of transgenic varieties that produce, uniquely for the target species, anthocyanins derived from delphinidin. These anthocyanins are ubiquitous in nature, and occur in both ornamental plants and common food plants. Through the extensive regulatory approval processes that must occur for the commercialization of genetically modified organisms, we have accumulated considerable experimental and trial data to show the accumulation of delphinidin based anthocyanins in the transgenic plants poses no environmental or health risk

    Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages

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    Amorphous silica nanoparticles (nSP) have been used as a polishing agent and/or as a remineralization promoter for teeth in the oral care field. The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects. Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles. However, tartrate-resistant acid phosphatase (TRAP) activity and the number of osteoclast cells (TRAP-positive multinucleated cells) were not changed by nSP treatment in the presence of receptor activator of nuclear factor κB ligand (RANKL) at doses that did not induce cytotoxicity by silica particles. These results indicated that nSP did not cause differentiation of osteoclasts. Collectively, the results suggested that nanosilica exerts no effect on RANKL-induced osteoclast differentiation of RAW264.7 cells, although a detailed mechanistic examination of the nSP70-mediated cytotoxic effect is needed
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