Publications by authors named "Hiroshi Shimoyama"

An 88-year-old man with congenital hemophilia A developed end-stage renal disease due to microscopic polyangiitis. He was at risk for catheter-related infection because he was taking immunosuppressive agents for the treatment of polyangiitis. He was also unable to manipulate the peritoneal dialysis device.

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High-quality color output from digital photocopiers and laser printers is in strong demand, motivating attempts to achieve fine dot reproducibility and stability. The resolution of a digital photocopier depends on the charge density distribution on the organic photoconductor surface; however, directly measuring the charge density distribution is impossible. In this study, we propose a new electron optical instrument that can rapidly measure the electrostatic latent image on an organic photoconductor surface, which is a dielectric surface, as well as a novel method to quantitatively estimate the charge density distribution on a dielectric surface by combining experimental data obtained from the apparatus via a computer simulation.

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A photoimprint-based immobilization process is presented for cylindrical viruses on the surface of an azobenzene-bearing acrylate polymer by using atomic force microscopy (AFM). Tobacco mosaic virus (TMV), 18 nm in diameter and ca. 300 nm in length, was employed as a model virus.

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A simple and quick method to measure the electric field distribution near a specimen using a conventional transmission electron microscope has been developed. The electric field distribution around a field emitter needle was measured to evaluate the performance of the method. It was found that this method allows us to measure the 2D distribution of electric field quantitatively with error of <10% with submicron spatial resolution.

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The paraxial trajectory method has been generalized for the application to the cathode rays inside electron guns. The generalized method can handle rays that initially make a large angle with the optical axis with a satisfactory accuracy. The key to success of the generalization is the adoption of the trigonometric function sine for the trajectory slope specification, instead of the conventional use of the tangent.

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Neuropathic pain, a highly debilitating pain condition that commonly occurs after nerve damage, is a reflection of the aberrant excitability of dorsal horn neurons. This pathologically altered neurotransmission requires a communication with spinal microglia activated by nerve injury. However, how normal resting microglia become activated remains unknown.

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A new numerical simulation method is presented for the electron optical property analysis of probe forming systems with point cathode guns such as cold field emitters and the Schottky emitters. It has long been recognized that the gun aberrations are important parameters to be considered since the intrinsically high brightness of the point cathode gun is reduced due to its spherical aberration. The simulation method can evaluate the 'threshold beam current I(th)' above which the apparent brightness starts to decrease from the intrinsic value.

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The paraxial lens theory cannot directly be applied to the cathode trajectories inside the gun. This inconvenience makes the interpretation of cathode trajectories difficult since one cannot use the physical concepts familiar in the paraxial lens theory, such as focal length and magnification factor. We have proposed the canonical mapping transformation (CMT) to describe the electron trajectories inside the gun by relating the ray conditions on the cathode surface to those in the crossover plane.

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This paper describes a control and monitoring system for the field emission (FE) gun in the high-voltage electron microscope (HVEM), where the whole FE gun system is located inside a pressure vessel and is floated on a high voltage of 1 MV. The operating condition of the FE gun system is controlled and monitored mainly by a bi-directional communication system between ground and high potential through optical fibres. A mechanical driving system by combination of insulator rods and stepping motors is partially used as a control system for FE gun operation.

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