Gifu University of Medical Science

About: Gifu University of Medical Science is a education organization based out in Gifu City, Japan. It is known for research contribution in the topics: Imaging phantom & Motion sickness. The organization has 89 authors who have published 202 publications receiving 1350 citations.

Quantification of ustalic acid, a chemotaxonomic marker, in Tricholoma ustale using liquid chromatography–mass spectrometry

Abstract: The development of methods for the detection and qualification of toxic substances in mushrooms is a rapidly growing research area in forensic toxicology. This study aimed to determine liquid chromatographic and mass spectrometric conditions applicable to the analysis of ustalic acid (UA) in Tricholoma ustale. We used HPLC coupled with single quadrupole mass spectrometry (Q-MS) with electrospray ionization in its negative ion mode to analyze UA. We performed HPLC separations on a C18 reversed-phase column with gradient elution using mobile phases containing water, acetonitrile, and formic acid. The MS showed that UA formed the deprotonated molecular ion [M–H]− at m/z 337, which was sufficient for the quantitative analysis of the compound. The average recovery rates of UA from four edible mushrooms (Flammulina velutipes, Pleurotus eryngii, Lentinula edodes, and Grifola frondosa) to which 10.0 μg/g of UA was added were 108%, 104%, 108%, and 107%, respectively, and the relative standard deviation values ranged from 4.1 to 6.4%. Quantitative analysis of UA in three systematically collected individual mushrooms of T. ustale revealed 41.9–155.7 ppm in each dry material. We also explored the fragmentation behaviors of UA in triple quadrupole mass spectrometry and the proposed structures for the product ions. The data suggest that conventional Q-MS with authenticated UA would be able to identify this compound in T. ustale when used for the immediate inspection of incidences of poisoning. Confirmation of the presence of UA in T. ustale would ultimately allow for the chemotaxonomic discrimination of Tricholoma species.

Development of a single-photon-counting camera with use of a triple-stacked micro-channel plate.

Abstract: At the quantum-mechanical level, all substances (not merely electromagnetic waves such as light and X-rays) exhibit wave–particle duality. Whereas students of radiation science can easily understand the wave nature of electromagnetic waves, the particle (photon) nature may elude them. Therefore, to assist students in understanding the wave–particle duality of electromagnetic waves, we have developed a photon-counting camera that captures single photons in two-dimensional images. As an image intensifier, this camera has a triple-stacked micro-channel plate (MCP) with an amplification factor of 10(6). The ultra-low light of a single photon entering the camera is first converted to an electron through the photoelectric effect on the photocathode. The electron is intensified by the triple-stacked MCP and then converted to a visible light distribution, which is measured by a high-sensitivity complementary metal oxide semiconductor image sensor. Because it detects individual photons, the photon-counting camera is expected to provide students with a complete understanding of the particle nature of electromagnetic waves. Moreover, it measures ultra-weak light that cannot be detected by ordinary low-sensitivity cameras. Therefore, it is suitable for experimental research on scintillator luminescence, biophoton detection, and similar topics.

Effect of computed tomography value error on dose calculation in adaptive radiotherapy with Elekta X-ray volume imaging cone beam computed tomography.

Abstract: Purpose We evaluated the effect of changing the scan mode of the Elekta X-ray volume imaging cone beam computed tomography (CBCT) on the accuracy of dose calculation, which may be affected by computed tomography (CT) value errors in three dimensions. Methods We used the electron density phantom and measured the CT values in three dimensions. CT values were compared with planning computed tomography (pCT) values for various materials. The evaluated scan modes were for head and neck (S-scan), chest (M-scan), and pelvis (L-scan) with various collimators and filter systems. To evaluate the effects of the CT value error of the CBCT on dose error, Monte Carlo calculations of dosimetry were performed using pCT and CBCT images. Results The L-scan had a CT value error of approximately 800 HU at the isocenter compared with the pCT. Furthermore, inhomogeneity in the longitudinal CT value profile was observed in the bone material. The dose error for ±100 HU difference in CT values for the S-scan and M-scan was within ±2%. The center of the L-scan had a CT error of approximately 800 HU and a dose error of approximately 6%. The dose error of the L-scan occurred in the beam path in the case of both single field and two parallel opposed fields, and the maximum error occurred at the center of the phantom in the case of both the 4-field box and single-arc techniques. Conclusions We demonstrated the three-dimensional CT value characteristics of the CBCT by evaluating the CT value error obtained under various imaging conditions. It was found that the L-scan is considerably affected by not having a unique bowtie filter, and the S-scan without the bowtie filter causes CT value errors in the longitudinal direction. Moreover, the CBCT dose errors for the 4-field box and single-arc irradiation techniques converge to the isocenter.

Examining Japanese women's preferences for a new style of postnatal care facility and its attributes.

Abstract: Perinatal care in rural Japan is currently facing a crisis because of the lack of medical staff, especially obstetricians. In this study, a new style of postnatal care facility that combines both medical and nonmedical support is considered. Contrary to most postnatal care facilities in Japan, this new postnatal care facility accepts a puerperant from the cooperating maternity facility soon after birth (≤2 days). We conducted a hypothetical choice experiment to investigate whether this new postnatal care facility could be accepted by women in Gero City, Hida, Gifu Prefecture and how these women evaluate different kinds of postnatal care services. The results show that after a 2-day hospital stay, women from Gero City preferred to move to the new postnatal care facility over the other alternatives (continued hospitalization or discharge home). In addition, the estimated choice probabilities for selecting the postnatal care facility under different scenarios show a high level of acceptance for this new postnatal care facility.

Numerical Analysis of Body Sway for Evaluation of 3D Sickness

Abstract: We have applied this artificial intelligence (AI) system to numerical simulations of the stabilogram whose randomness is remarkably greater than that of the other bio-signal in accordance with the nonlinear analysis. We have succeeded in findings of the mathematical models of the body sway in the elderly with use of the Generative Adversarial Networks (GANs). Trying to visualize internal state of the discriminator layer in our GAN, we can discuss how the AI captures the feature of patterns in the stabilograms recorded during the 3D sickness. Especially in the stabilograms measured during the 3D sickness, cusp patterns could be extracted as a high contribution to the output of the discriminator.