A heavy-ion beam has been recognized as an effective mutagen for plant breeding and applied to the many kinds of crops including rice. In contrast with X-ray or γ-ray, the heavy-ion beam is characterized by a high linear energy transfer (LET). LET is an important factor affecting several aspects of the irradiation effect, e.g. cell survival and mutation frequency, making the heavy-ion beam an e...

As is well documented, platinum nanoparticles, promising for catalysts for fuel cells, exhibit better catalytic activities, when alloyed with Zn. Pre-existing syntheses of Pt-Zn alloy catalysts are composed of a number of complex steps. In this study, we have demonstrated that nanoparticles of Pt-Zn alloys are simply generated by electron-beam irradiation in a transmission electron microscope o...

Surgical resection with a tumor-free margin is the only curative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beam irradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unre...

Clinical trials of boron neutron capture therapy (BNCT) for recurrent breast cancers are considered at Japan Research Reactor No. 4 (JRR-4). In this study, the irradiation technique for a total mastectomy patient with recurrent cancer was optimized by dosimetric calculations using JAEA computational dosimetry system (JCDS). The evaluation was performed using an en face technique and a tangents ...

Beam commissioning of the new proton therapy system for University of Tsukuba was started in September 2000. The present system employs a synchrotron with a maximum energy of 250MeV and two rotating gantries. The beam was successfully accelerated up to 250MeV and transported to the irradiation nozzles. The position of the beam extracted from the synchrotron was confirmed to be very stable and s...

In this article, we first address how the indirect-drive irradiation geometry must be modified to accommodate direct drive. Emphasis is placed on finding an acceptable direct-drive geometry that minimizes the amount of reconfiguration. Tolerances for energy imbalance, beam mispointing, and target-positioning errors are discussed for the proposed irradiation geometry. The beam uniformity that ca...

In this study, the efficacy of electron beam irradiation versus chemical coupling for yielding polyethersulfone (PES) membranes with antibacterial properties was investigated. For the surface coating, a recently discovered lead compound, IL-KKA, comprising a short peptide sequence functionalized with imidazolium groups, was used. For better integration within the membrane, several novel variant...

On the other hand, brachytherapy combined with external beam irradiation is not a good therapeutic approach in advanced disease because, in this case, the brachytherapy target volume would be by definition identical for a primary brachytherapy and/or for a brachytherapy boost. (8,11) For any tumour size, the combination of external beam irradiation and brachytherapy boost yields worse results t...

Surgical resection with a tumor-free margin is the only curative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beam irradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unre...