A5006536628- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Catalytic Processes in Materials Science
- Zeolite Catalysis and Synthesis
- Nuclear Physics and Applications
- Nuclear physics research studies
- Cancer therapeutics and mechanisms
- Radiation Dose and Imaging
- DNA and Nucleic Acid Chemistry
- Catalysis and Oxidation Reactions
- Atomic and Subatomic Physics Research
- Advanced X-ray and CT Imaging
- Mesoporous Materials and Catalysis
- Catalysis and Hydrodesulfurization Studies
- Advanced NMR Techniques and Applications
- Radiation Effects and Dosimetry
- Boron Compounds in Chemistry
- Quantum Chromodynamics and Particle Interactions
- Radiation Effects in Electronics
- Effects of Radiation Exposure
- Catalysis for Biomass Conversion
- Industrial Gas Emission Control
- Photodynamic Therapy Research Studies
Nagoya University
2019-2025
Kitasato University
1997-2020
Futaba (Japan)
2017
Waseda University
1995-2015
Gakushuin University
2009
Tokyo Institute of Technology
2001-2003
RIKEN
2003
Mitsubishi Research Institute (Japan)
2000
While the FLASH radiotherapy (FLASH RT) using ultra-high-dose-rate (UHDR) proton beams has potential to achieve more effective cancer treatment, reliable and practical dosimetry of UHDR remains challenging. Although commercial radiochromic films, named "Gafchromic film," can be promising tools for measurements beam profiles, these films have some unfavorable features such as scanning orientation effects lateral response artifacts. In this study, we examined Gafchromic EBT3 irradiated with...
Abstract Selective reduction of nitric oxide with methane or ethane in the presence excess oxygen was investigated using a gallium ion-exchanged ZSM-5 zeolite catalyst(Ga-ZSM-5). Ga-ZSM-5 highly active and selective for NO above 400 °C. The limiting molar ratios reacted to consumed carbon C2H6 CH4 at 500 °C were found be 1.5 2, respectively.
Abstract H-form Fe-silicate catalysts showed high activity and stability for the reduction of NO with propylene in presence a concentration oxygen. The catalytic was hardly affected by SO2.
Abstract The reduction of NO with propane in the presence excess oxygen was investigated using gallium ion-exchanged zeolite catalysts, among which ferrierite(Ga-ferrierite) and ZSM-5(Ga-ZSM-5) showed high activity a wide range reaction temperature.
Significance Reverse gyrase resides in bacteria that live hot conditions. The enzyme further intertwines the double helix of DNA to make it tighter. In biochemical assays, reverse appears quite inefficient, requiring many molecules per and yet taking minutes wind up. Here, we show one molecule rapidly overwinds relaxed but begins idle as torsion accumulates. Excess would hamper replication/transcription activities, whereas quick restoration modest prevents thermal denaturation DNA. We...
The electric quadrupole moment Q for the ground state of ${}^{17}\mathrm{B}$ was determined by $\ensuremath{\beta}$-NMR method applied to spin-polarized projectile fragments. From measured coupling constant, $|{eqQ/h(}^{17}\mathrm{B}\mathrm{in}\mathrm{}\mathrm{Mg})|=137.4\ifmmode\pm\else\textpm\fi{}4.5\mathrm{kHz},$ in a Mg single crystal stopper deduced as $|{Q(}^{17}\mathrm{B})|=38.6\ifmmode\pm\else\textpm\fi{}1.5\mathrm{mb}.$ As case previous ${}^{15}\mathrm{B}$ result, obtained is very...
Gold nanoparticles (AuNPs) can be used with megavolt (MV) X-rays to exert radiosensitization effects, as demonstrated in cell survival assays and mouse experiments. However, the detailed mechanisms are not clear; besides physical dose enhancement, several chemical biological processes have been proposed. Reducing AuNP concentration while achieving sufficient enhancement is necessary for clinical application of AuNPs. Here, we positively charged (+) AuNPs determine effects combined MV on DNA...
Abstract Objective. FLASH radiation therapy with ultrahigh dose rates (UHDR) has the potential to reduce damage normal tissue while maintaining anti-tumor efficacy. However, rapid and precise distribution measurements remain difficult for proton beams. To solve this problem, we performed luminescence imaging of water following irradiation by a UHDR beam captured using charge-coupled device camera. Approach . We used 60 MeV beams 0.03–837 Gy s −1 from cyclotron. Therapeutic 139.3 0.45–4320...
Quality assurance (QA) of clinical electron beams is essential for performing accurate and safe radiation therapy. However, with advances in therapy, QA has become increasingly labor-intensive time-consuming. In this paper, we propose a tissue-equivalent plastic scintillator quick easy beams. The proposed tool comprises plate charge-coupled device camera that enable the scintillation light by to be recorded high sensitivity spatial resolution. Further, Cerenkov image directly subtracted from...
Type-II DNA topoisomerases resolve entanglements such as supercoils, knots and catenanes by passing one segment of duplex through a transient enzyme-bridged double-stranded break in another segment. The ATP-dependent passage reaction has previously been demonstrated at the single-molecule level, showing apparent processivity saturating ATP. Here we directly observed strand human topoisomerase IIα, after winding pair fluorescently stained molecules with optical tweezers for 30 turns into an...
Abstract The accuracy of computed tomography number to electron density ( CT ‐ ED ) calibration is a key component for dose calculations in an inhomogeneous medium. In previous work, it was shown that the tolerance levels became stricter with increase tissue thickness and decrease effective energy photon beam. For last decade, low beam (e.g., flattening‐filter‐free FFF )) has been used clinical sites. However, its level not established yet. We relative each type were calculated using maximum...
Abstract With advances in high-dose-rate (HDR) brachytherapy, the importance of quality assurance (QA) is increasing to ensure safe delivery treatment by measuring dose distribution and positioning source with much closer intervals for highly active sources. However, conventional QA time-consuming, involving use several different measurement tools. Here, we developed simple method HDR brachytherapy based on imaging Cherenkov emission evaluated its performance. Light from pure water...
Gold nanoparticles (AuNPs) are candidate radiosensitizers for medium-energy photon treatment, such as γ-ray radiation in high-dose-rate (HDR) brachytherapy. However, high AuNP concentrations required sufficient dose enhancement clinical applications. Here, we investigated the effect of positively (+) charged radiosensitization plasmid DNA damage induced by 192Ir γ-rays, and compared it with that negatively (-) AuNPs.We observed breaks reactive oxygen species (ROS) generation presence AuNPs...
Abstract Objective . Precise monitoring of the position and dwell time iridium-192 (Ir-192) during high-dose-rate (HDR) brachytherapy is crucial to avoid serious damage normal tissues. Source imaging using a compact gamma camera potential approach for monitoring. However, images from are affected by blurring statistical noise, which impact accuracy source This study aimed develop deep-learning estimating ideal that reduce effect noise experimental captured camera. Approach A double pix2pix...