92 research outputs found

    Design of a hybrid plasmonic waveguide device using a trench structure

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    A hybrid plasmonic waveguide device was designed using a trench structure. This waveguide device was designed to improve the affinity of plasmonic devices with optical circuits by connecting them with traditional waveguide structures. The waveguide device consists of three structural segments, comprising two traditional waveguide sections for input and transmission and a hybrid plasmonic waveguide. The designed waveguide structure was evaluated using numerical analysis techniques such as the finite-difference time-domain method. The device's transmission property affects the interference between the guided light and the surface plasmon polaritons. Controlling the length of the hybrid waveguide device, which is composed of a traditional waveguide coated with a gold layer, allows the transmission intensity of the device to be controlled. The device's transmission characteristic can be controlled based on the relationship between the wavelength of the incident light and the length of the hybrid waveguide device. The device will transmit only specific incident light wavelengths because the length of the hybrid plasmonic waveguide remains constant. The characteristics of this device indicate potential for applications to nanoscale devices, optical integrated circuits and plasmonic sensors

    Determining the Optical Geometry of a Gold Semi-Shell under the Kretschmann Configuration

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    Dielectric nanoparticles coated with metals (half-shell or semi-shell structures) have attracted attention as potential composite plasmonic nanomaterials with large optical anisotropy and absorption cross-sections. Structures approximately 100 nm in size can excite plasmons in the visible and near-infrared ranges, highlighting their distinct optical properties. This study employed metal semi-shell structures (metal: gold, dielectric: silica) in the Kretschmann configuration to experimentally and numerically demonstrate the optical determination of single-structure orientations through a finite-difference time-domain method. Gold semi-shell structures were fabricated through deposition and etching. These structures were removed from their substrate in ultrapure water and randomly dropped onto a thin gold substrate. In the single structure, we experimentally observed changes in the scattering light spectrum based on the optical geometry of the gold semi-shell at wavelengths ranging from 530 to 700 nm. The obtained results closely resembled those of a simulation and confirmed the presence of eigenmodes in the orientation through electric field analysis. These observations allow for the cost-effective and rapid determination of the orientations of numerous structures that are approximately 100 nm in size, solely through optical methods. This technique is a valuable development for measurement applications in nanostructure orientation control and functionality enhancement

    Ability of Three Temperate Grasses to Compete with \u3cem\u3ePhalaris arundinacea\u3c/em\u3e L.

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    Weeds with rhizomes have become an ever-increasing problem in the grasslands of Hokkaido in northern Japan. Many meadows in the Tenpoku region, located in the northernmost part of Hokkaido, have been invaded by Phalaris arundinacea L., a grass with aggressive colonising ability known as the primary and most difficult to control weed in the Tenpoku region. However, dairy farmers in the grasslands of the Tenpoku region most commonly cultivate Phleum pratense L., in spite of its low competitive ability. The Tenpoku region frequently experiences years of low rainfall or drought, but P. pratense has low tolerance to drought (Okamoto et al., 2012; Okamoto and Furudate, 2010). Lolium perenne L. and Dactylis glomerata L. are also cultivated in the Tenpoku region, where they are used as rough forages; however, they are much less commonly cultivated than P. pratense. These species are thought to possess not only higher competitive ability than other grasses, but also higher drought tolerance than P. pratense, and thus may be more suitable for cultivation in some parts of the Tenpoku region. Therefore, we suggest that farmers choose a grass species suitable for their land. To further develop this concept, it is necessary to elucidate the differences among the abilities of these species to compete with invading P. arundinacea. Therefore, the objective of this study was to evaluate and compare the competitive ability of these temperate grass species (L. perenne, D. glomerata, and P. pratense) with those of P. arundinacea

    Gap plasmon excitation in plasmonic waveguide using Si waveguide

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    Plasmonic waveguides have attracted considerable attention for application in highly integrated optical circuits since they can confine light to areas smaller than the diffraction limit. In this context, in order to realize a highly integrated optical circuit, we fabricate and evaluate the optical characteristics of a poly(methyl methacrylate) junction positioned between Si and plasmonic waveguides. For the plasmonic waveguide, we employ a gap plasmonic waveguide in which the energy of the plasmonic wave can be confined in order to reduce the scattering loss at the junction. By experimental measurement, we determine the coupling efficiency between the Si and gap plasmonic waveguides and the propagation length at the gap plasmonic waveguide to be 52.4% and 11.1 µm, respectively. These values agree with those obtained by the three-dimensional finite-difference time-domain simulation. We believe that our findings can significantly contribute to the development of highly integrated optical circuits

    Dentin phosphophoryn promotes cellular migration of human dental pulp cells

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    Dentin phosphophoryn (DPP) is a dentin sialophosphoprotein gene product that has an RGD motif and repeat sequences of aspartic acid and phosphoserine. To date, the function of DPP in the early stage of reparative dentin formation still remains unclear. The objective of this study was to evaluate the effects of DPP on pulp cell migration and proliferation. DPP promoted cell migration in a concentration-dependent manner, thus increasing it by about 3-fold at 1000 ng/mL compared with the control, but it had no effect on cell proliferation. Dephosphorylated DPP also promoted cell migration, similarly to DPP. However, cell migration was significantly suppressed by the addition of αvβ3 integrin antibody to the medium. Furthermore, porcine DPP-derived RGD peptide, but not its mutant RAD peptide, significantly promoted cell migration. These results indicated that the RGD motif of DPP plays an important role in the migration of human dental pulp cells

    31P nuclear magnetic resonance evaluation of rat liver preserved in UW solution.

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    A persistent problem in orthotopic liver transplantation is primary nonfunction (PNF) of the hepatic allograft. In an attempt to reduce the incidence of graft failure, the feasibility of pretransplant assessment of graft viability was investigated by 31P nuclear magnetic resonance (NMR) spectroscopy. The level of adenosine triphosphate (ATP) was measured as an indicator of liver function by 31P NMR spectroscopy after a 30 min normothermic reperfusion following cold-storage in University of Wisconsin (UW) solution. The mean +/- SD beta-ATP/Pi ratio after preservation for 0, 12, 24 or 48 h was 1.40 +/- 0.34, 0.85 +/- 0.27, 0.64 +/- 0.14 and 0.38 +/- 0.09, respectively. Significance was observed between 12h and 24h and between 12h and 48h of preservation. These results correlated well with the morphological changes in endothelial cells and sinusoidal lining cells examined by transmission electron microscopy. It is suggested strongly that microcirculatory disturbances due to endothelial cell injury impairs the recovery of ATP levels after reperfusion, and that ATP determination by 31P NMR spectroscopy, as a non-invasive modality, may help in the prediction of PNF after liver transplantation.</p

    繊維集合体における微小面積部分の配色に関する研究(第4報) : 2色杢糸における色の見分けとメランジ配色の効果

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    Color discrimination and desirable melange effect in the colored two-ply yarns were assessed by 20 observers in visual testing the seriplanes of the plied two-colored yarns together with the dyed single yarns of three primary colors and of 12 vivid colors, respectively, which were carefully prepared after color-matching with the color cards of vivid tone on the color ring of PCCS (Practical Color Coordinate System). The results of the color discrimination and desirable color combinations were discussed in the relation to color differences between the two colors in the ply yarns. It was necessary for desirable melange color effect of the two colored ply yarns to select medium hue contrast combination. High hue contrast combination to be consequently high color differences between the two colored yarns led the color discrimination to improve, while it also led the desirable melange effect to change for the worse. The result of the desirable color effects in the colored yarns was different from that in the colored fiber assemblies previously reported, due to size as a visual object

    Sterilization effect of UV light on Bacillus spores using TiO2 films depends on wavelength

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    UV light and photocatalysts such as titanium dioxide (TiO2) and silver (Ag) are useful for disinfection of water and surfaces. However, the effect of UV wavelength on photocatalytic disinfection of spores is not well understood. Inactivation of Bacillus spores has been examined using different UV wavelengths and TiO2 or TiO2/Ag composite materials. The level of UVA disinfection of Bacillus anthracis and Bacillus brevis vegetative cells increased with the presence of the TiO2 and Ag photocatalysts, but had little effect on their spores. B. brevis spores were slightly more sensitive to UVB and UVC than the spores of B. atrophaeus. Photocatalytic sterilization against spores was strongest in UVC and UVB and weakest in UVA. The rate of inactivation of Bacillus spores was significantly increased by the presence of TiO2, but was not markedly different from that induced by the presence of Ag. Therefore, TiO2/Ag plus UVA can be used for the sterilization of vegetative cells, while TiO2 and UVC are effective against spores

    Diabetes mellitus itself increases cardio- cerebrovascular risk and renal complications in primary aldosteronism

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    This is a pre-copyedited, author-produced version of an article accepted for publication in The Journal of Clinical Endocrinology & Metabolism following peer review. The version of record Aya Saiki, Michio Otsuki, Daisuke Tamada, Tetsuhiro Kitamura, Iichiro Shimomura, Isao Kurihara, Takamasa Ichijo, Yoshiyu Takeda, Takuyuki Katabami, Mika Tsuiki, Norio Wada, Toshihiko Yanase, Yoshihiro Ogawa, Junji Kawashima, Masakatsu Sone, Nobuya Inagaki, Takanobu Yoshimoto, Ryuji Okamoto, Katsutoshi Takahashi, Hiroki Kobayashi, Kouichi Tamura, Kohei Kamemura, Koichi Yamamoto, Shoichiro Izawa, Miki Kakutani, Masanobu Yamada, Akiyo Tanabe, Mitsuhide Naruse, Diabetes Mellitus Itself Increases Cardio-Cerebrovascular Risk and Renal Complications in Primary Aldosteronism, The Journal of Clinical Endocrinology & Metabolism, Volume 105, Issue 7, July 2020, Pages e2531–e2537 is available online at: https://doi.org/10.1210/clinem/dgaa177

    Qualitative investigation of the factors that generate ambivalent feelings in women who give birth after receiving negative results from non-invasive prenatal testing

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    Background: Women who receive negative results from non-invasive prenatal genetic testing (NIPT) may find that they later have mixed or ambivalent feelings, for example, feelings of accepting NIPT and regretting undergoing the test. This study aimed to investigate the factors generating ambivalent feelings among women who gave birth after having received negative results from NIPT. Methods: A questionnaire was sent to women who received a negative NIPT result, and a contents analysis was conducted focusing on ambivalent expressions for those 1562 women who responded the questionnaire. The qualitative data gathered from the questionnaire were analyzed using the N-Vivo software package. Results: Environmental factors, genetic counseling-related factors, and increased anticipatory anxiety, affected the feeling of ambivalence among pregnant women. Furthermore, pregnant women desired more information regarding the detailed prognosis for individuals with Down syndrome and living with them and/or termination, assuming the possibility that they were positive. Conclusions: Three major interrelated factors affected the feeling of ambivalence in women. Highlighting and discussing such factors during genetic counseling may resolve some of these ambivalences, thereby enhancing the quality of decisions made by pregnant women
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