Cell-cycle dependence on the biological effects of boron neutron capture therapy and its modification by polyvinyl alcohol

Matsuya, Yusuke; Sato, Tatsuhiko; Kusumoto, Tamon*; Yachi, Yoshie*; Seino, Ryosuke*; Miwa, Misako*; Ishikawa, Masayori*; Matsuyama, Shigeo*; Fukunaga, Hisanori*

Scientific Reports (Internet), 14, p.16696_1 - 16696_14, 2024/07

https://doi.org/10.1038/s41598-024-67041-6

Boron neutron capture therapy (BNCT) is a unique radiotherapy to selectively eradicate tumor cells using boron compounds (e.g., 4-borono-L-phenylalanine [BPA]) that are heterogeneously taken up at the cellular level. However, the impacts of tempo-spatial heterogenicity on cell killing remain unclear. With the technical combination of radiation track detector, cell cycle analysis, and biophysical simulations, we demonstrated the cell cycle-dependent heterogenicity of BPA uptake and following biological impacts of B(n, )Li reactions in HeLa cells expressing Fluorescent Ubiquitination-based Cell Cycle Indicators (FUCCI), as well as its modification effects of polyvinyl alcohol (PVA). As a result, we revealed that the intracellular BPA concentration in the S/G2/M phase was higher than that in the G1/S phase and that PVA modified the cell cycle dependence. Further, these findings lead to the development of the first BPA-PVA-based model for predicting BNCT treatment effects. These outcomes may contribute to more precision of therapeutic efficacy, when BNCT is combined with PVA and/or cell cycle-specific anticancer agents.

Origin of magnetovolume effect in a cobaltite

Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.

Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03

https://doi.org/10.1103/PhysRevB.103.094302

The layered perovskite PrBaCoO demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCoO is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.

On-site background measurements for the J-PARC E56 experiment; A Search for the sterile neutrino at J-PARC MLF

Ajimura, Shuhei*; Bezerra, T. J. C.*; Chauveau, E.*; Enomoto, T.*; Furuta, Hisataka*; Harada, Masahide; Hasegawa, Shoichi; Hiraiwa, T.*; Igarashi, Yoichi*; Iwai, Eito*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.063C01_1 - 063C01_19, 2015/06

https://doi.org/10.1093/ptep/ptv078

The J-PARC E56 experiment aims to search for sterile neutrinos at the J-PARC Materials and Life Science Experimental Facility (MLF). In order to examine the feasibility of the experiment, we measured the background rates of different detector candidate sites, which are located at the third floor of the MLF, using a detector consisting of plastic scintillators with a fiducial mass of 500 kg. The gammas and neutrons induced by the beam as well as the backgrounds from the cosmic rays were measured, and the results are described in this article.

Data on Plutonium Sorption onto Cementitious Materials under Conditions of Reducing and of Presence of Nitrate

Suguro, Toshiyasu; Notoya, Shin; Nishikawa, Yoshiaki*; Nakamura, Ryosuke*; Shibutani, Tomoki; Kuroha, Mitsuhiko; Kamei, Gento

JNC TN8430 2004-004, 27 Pages, 2005/01

JNC-TN8430-2004-004.pdf:1.03MB

In terms of safety assessment of TRU waste disposal, data on plutonium sorption on cementitious materials have been obtained by means of a static batch-type experiment. Because the repository condition will be reducing and be affected by considerable amount of nitrate, the authors carried out the experiments using ordinary portland cement (OPC) under the reducing (NaSO as added as reductant) and anoxic condition (O 1ppm) and solution of 0 to 0.5 M NaNO. Other experimental conditions are : liquid/solid (L/S) ratios ; 100 and 1000 mL g, Initially aaded plutonium; 2.8410M, Temperature; 255C and Reaction times; 7, 14 and 28 days. The experimental results suggest that distribution coefficient () ranges 50 to 1000 mL g in case of L/S=100mL g. Similarly the ranges, 100 to 10000 mL g at L/S=1000mL g. These values tend to increase with lapsing reaction time. On the basis of these results, we recommend 50mL g as a conservative value of plutonium on OPC in a TRU waste repository condition.

Present and future statuses of search experiment for sterile neutrino at MLF of J-PARC

Meigo, Shinichiro; Hasegawa, Shoichi; Nishikawa, Yuichiro; Maruyama, Takasumi*; Iwai, Eito*; Ota, Ryosuke*

no journal, , 

no abstracts in English