111 research outputs found

    Proposal on Model Based Current Overshoot Suppression of Receiver Side Coil in Drone Wireless Power Transfer System

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    This paper proposes a model-based control method in the wireless power transfer (WPT) system by operating a semi-bridgeless active rectifier (SBAR) to suppress the secondary coil current overshoot. By damping the current overshoot, it is possible to reduce the rectifier's rated current and decrease the rectifier's size, which is beneficial for the lightweight-oriented system such as drones. In the control method, an inverse of the plant model is used to calculate the reference input to the system. The current overshoot is reduced by operating the SBAR under the duty ratio calculated from the model. To confirm the performance of the proposed method, the simulation and the experiment using the WPT prototype are conducted. The experimental results show that the proposed method can suppress the secondary coil current overshoot. The results suggest it is possible to realize the lighter secondary system by applying the proposed method.Comment: This paper was presented at IEEE 2022 Wireless Power Week (WPW

    Test Bench Study on Attitude Estimation in Ground Effect Region Based on Motor Current for In-Flight Inductive Power Transfer of Drones

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    To overcome the short flight duration of drones, research on in-flight inductive power transfer has been recognized as an essential solution. Thus, it is important to accurately estimate and control the attitude of the drones which operate close to the charging surface. To this end, this paper proposes an attitude estimation method based solely on the motor current for precision flight control in the ground effect region. The model for the estimation is derived based on the motor equation when it rotates at a constant rotational speed. The proposed method is verified on the simulations and experiments. It allows simultaneous estimation of altitude and pitch angle with the accuracy of 0.30\hspace{0.5mm}m and 0.04 rad, respectively. The minimum transmission efficiency of the in-flight power transfer system based on the proposed estimation is calculated as 95.3 %, which is sufficient for the efficient system.Comment: This paper was presented at The 49th Annual Conference of the IEEE Industrial Electronics Society (IECON2023

    A Fast Runtime Visualization of a GPU-Based 3D-FDTD Electromagnetic Simulation

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    In this paper, we present design and implementation of a fast runtime visualizer for a GPU-based 3D-FDTD electromagnetic simulation. We focus on improving the productivity of simulator development without compromising simulation performance. In order to keep the portability, we implemented a visualizer with the MVC model, where simulation kernels and visualization process were completely separated. For high-speed visualization, an interoperability mechanism between OpenGL and CUDA was used in addition to efficient utilization of programmable shaders. We also propose an asynchronous multi-threaded execution with a triple-buffering technique so that developers can concentrate on developing their simulation kernels. As a result of empirical visualization experiments of electromagnetic simulations for practical antenna design, it was revealed that our implementation achieved a rendering throughput of 90 FPS for a view port of 512 x 512 pixels, which corresponds to a 12.9 times speedup compared to when the OpenGL-CUDA interoperability mechanism was not utilized. When a standard visualization throughput of 60 FPS was selected, the performance overhead imposed by the visualization process was 15.8%, which was reasonably low compared to a speedup of the simulation kernel gained by the GPU acceleration

    去勢抵抗性前立腺癌におけるKlothoγのドセタキセル抵抗性との関連と新規治療としての可能性

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    The Klotho (KL) gene was first identified as a potent aging suppressor. The KL family currently comprises of three proteins: α-Klotho (KLA), β-Klotho (KLB), and γ-Klotho (KLG). Many studies have shown that KLA and KLB participate in tumor progression or suppression, depending on the type of cancer; however, the relationship between KLG and prostate cancer has not yet been studied. Some studies have claimed that KL is correlated to sensitivity to chemotherapy. Here, we investigated the oncogenic potential of KLG in castration-resistant prostate cancer (CRPC). Immunohistochemical analysis using prostate biopsy specimens revealed that patients with high KLG expression in primary prostate cancer tissue had a significantly poor prognosis for overall survival. In addition, the prostate-specific antigen response rate after docetaxel (DTX) therapy in patients with high KLG expression was lower than that in patients with low KLG expression. To evaluate the potential of KLG as a therapeutic target in human prostate cancer, we generated a xenograft model of human CRPC cell line (PC-3) in male athymic mice. The animals were randomly divided into four groups as follows: i) control group (vehicle only); ii) DTX group (intraperitoneal administration); iii) small interfering RNA targeting KLG (KLG siRNA) group (intratumoral administration); and iv) a combination group (DTX plus KLG siRNA). After 3 weeks of treatment, the tumor weight and tumor Ki-67 labeling index were significantly lower in the KLG siRNA group and the combination group than in the control group. Sensitivity to DTX was increased upon treatment with KLG siRNA. These findings suggest that KLG expression in primary prostate cancer lesions is associated with resistance to DTX in CRPC and has potential as a diagnostic and therapeutic target for patients with CRPC.博士(医学)・甲第740号・令和2年3月16日Copyright: © Onishiet al. This is an open access article distributed under theterms of CreativeCommons Attribution License(https://creativecommons.org/licenses/by-nc-nd/4.0/)

    A Study on Topology Optimization of Optical Circuits Consisting of Multi-Materials

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    A topology optimization method can be used to find out the optical waveguide structures which have the desired transmission characteristics. Using the function expansion method, we can avoid the problem of a gray area, which means that some areas having intermediate refractive index between those of usable materials appear in a design region. However, so far, topology optimization has mainly been studied for structures consisting of two isotropic materials. In this paper, we study the applicability of topology optimization to structures which include three or more materials, and demonstrate the optimal design of a waveguide crossing

    Fluorescence and chemiluminescence behavior of distyrylbenzene bearing two arms of dipicolylaminomethyl groups: Interactions with zinc ion and ATP

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    Available online 31 January 2018.The absorption and fluorescence spectral study of the distyrylbenzene bearing two arms of the dipicolylaminomethyl groups, the effective ligands for Zn2+, was studied in the presence of Zn2+ and ATP. Upon complexation of the distyrylbenzene with zinc ions in acetonitrile, enhancement of the fluorescence intensity was observed due to inhibition of intramolecular PET (photo-induced electron transfer) quenching, but no effect was found in aqueous media because the equilibrium laid to the free form of the ligands. In contrast, the addition of ATP disodium salt was effective to enhance the fluorescence intensity of the combination of the distyrylbenzne and Zn2+ in aqueous media. This assembly was applied to the peroxyoxalate chemiluminescence system and a significant increase in the intensity was observed, which provides a potential detection for ATP by chemiluminescence. (C) 2018 Elsevier B.V. All rights reserved.ArticleSPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY. 195:223-229 (2018)journal articl

    限局性腎細胞癌における腫瘍浸潤性リンパ球と関連サイトカインの予後因子としての意義

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    Renal cell carcinoma (RCC) is an immunogenic tumor and pathological specimen generally contain large quantities of tumor-infiltrating lymphocytes (TILs). Numerous cell types and cytokines could affect the immune escape mechanism of tumor cells. The aim of the present study was to investigate the prognostic impact of TILs and the associated circulating cytokines on localized clear cell RCC following radical nephrectomy. A total of 87 patients who had undergone radical nephrectomy and were pathologically diagnosed with localized clear cell RCC were included. The present study evaluated the profile of TILs with immunohistochemical analysis of tumor specimens using a panel of antibodies [cluster of differentiation (CD)-4, CD8, CD80, CD86, CD276, and Forkhead box p3 (Foxp3)]. Counts of each TIL were compared with clinicopathological variables. Based on the results of immunohistochemical analyses, putative cytokines, including interleukin (IL)-6, IL-10, IL-17, interferon-γ, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β, were selected, and their levels in preoperative serum were measured by ELISA. The levels were compared with TIL counts in tumor specimens. High counts of the CD276+ and Foxp3+ TILs were identified as independent factors for poor prognosis for metastasis and local recurrence following radical nephrectomy (P=0.033 and 0.006, respectively). A high CD276+ TIL count was associated with preoperative serum levels of TNF-α and IFN-γ (P=0.027 and P=0.035, respectively), whereas a high count of Foxp3+ TILs was associated with preoperative serum levels of TGF-β (P=0.021). High levels of TNF-α and TGF-β were associated with recurrence-free survival (P=0.035 and P=0.031, respectively). Topical intra-tumoral immunoreaction and systemic immune status may be associated with patients with localized RCC. The topical induction of the CD276+ and Foxp3+ TILs was suggested to be associated with high levels of serum TNF-α and IFN-γ. Preoperative serum levels of TNF-α and TGF-β could be simple and non-invasive biomarkers for risk stratification before radical surgery.博士(医学)・甲第741号・令和2年3月16日Copyright © Spandidos Publications 2019. All rights reserved.Articles from Oncology Letters are provided here courtesy of Spandidos Publications

    Australian Cosmic Ray Modulation Research

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    Australian research into variations of the cosmic ray flux arriving at the Earth has played a pivotal role for more than 50 years. The work has been largely led by the groups from the University of Tasmania and the Australian Antarctic Division and has involved the operation of neutron monitors and muon telescopes from many sites. In this paper the achievements of the Australian researchers are reviewed and future experiments are described. Particular highlights include: the determination of cosmic ray modulation parameters; the development of modelling techniques of Ground Level Enhancements; the confirmation of the Tail-In and Loss-Cone Sidereal anisotropies; the Space Ship Earth collaboration; and the Solar Cycle latitude survey.Comment: 47 pages, 37 figures, LaTeX, invited review, in press PASA 18(1). HTML version available at http://www.atnf.csiro.au/pasa/18_1/duldig/paper

    Derivation of induced pluripotent stem cells in Japanese macaque (Macaca fuscata)

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    Non-human primates are our closest relatives and are of special interest for ecological, evolutionary and biomedical research. The Japanese macaque (Macaca fuscata) has contributed to the progress of primatology and neurosciences over 60 years. Despite this importance, the molecular and cellular basis of the Japanese macaque remains unexplored since useful cellular tools are lacking. Here we generated induced pluripotent stem cells (iPSCs) from skin fibroblasts of the Japanese macaque with Sendai virus or plasmid vectors. The Japanese macaque iPSCs (jm-iPSCs) were established under feeder-free culture conditions, but feeder cells turned out to be essential for their maintenance. The jm-iPSCs formed human iPSC-like flat colonies which were positive for pluripotent antigens including alkaline phosphatase, SSEA4, and TRA-1-81. They also expressed endogenous OCT3/4, SOX2, L-MYC, and KLF4 and other pluripotent marker genes. The potential to differentiate into all three germ layers and neural stem cells was confirmed by embryoid body and neurosphere formation, respectively. The jm-iPSCs will provide a robust in vitro tool for investigating the underlying mechanisms of development and physiology studies with the Japanese macaque

    尿路上皮癌微小環境内におけるDisabled Homolog 2 (DAB2) は腫瘍細胞上皮間葉転換を介して遊走能・浸潤能を高める

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    Disabled homolog-2 (DAB2) has been reported to be a tumor suppressor gene. However, a number of contrary studies suggested that DAB2 promotes tumor invasion in urothelial carcinoma of the bladder (UCB). Here, we investigated the clinical role and biological function of DAB2 in human UCB. Immunohistochemical staining analysis for DAB2 was carried out on UCB tissue specimens. DAB2 expression levels were compared with clinicopathological factors. DAB2 was knocked-down by small interfering RNA (siRNA) transfection, and then its effects on cell proliferation, invasion, and migration, and changes to epithelial-mesenchymal transition (EMT)-related proteins were evaluated. In our in vivo assays, tumor-bearing athymic nude mice subcutaneously inoculated with human UCB cells (MGH-U-3 or UM-UC-3) were treated by DAB2-targeting siRNA. Higher expression of DAB2 was associated with higher clinical T category, high tumor grade, and poor oncological outcome. The knock-down of DAB2 decreased both invasion and migration ability and expression of EMT-related proteins. Significant inhibitory effects on tumor growth and invasion were observed in xenograft tumors of UM-UC-3 treated by DAB2-targeting siRNA. Our findings suggested that DAB2 expression was associated with poor prognosis through increased oncogenic properties including tumor proliferation, migration, invasion, and enhancement of EMT in human UCB.博士(医学)・甲第768号・令和3年3月15日© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
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