Utility of the rurality index for Japan for exploring good practice solutions for declining birthrates in rural areas.

Background: Japan is experiencing unprecedented decreasing birthrates. This preliminary study aimed to identify the municipalities in Aomori Prefecture that are successfully tacking declining birthrates using the Rurality Index for Japan (RIJ).

Methods: We obtained 100-level RIJ and census data from 1980 to 2020 for children (age < 15 years) in the municipal population of Aomori Prefecture.

Real-world outcomes of avelumab plus axitinib in patients with advanced renal cell carcinoma in Japan: long-term follow-up from the J-DART2 retrospective study.

Background: Avelumab + axitinib was approved for advanced renal cell carcinoma (aRCC) in Japan in December 2019. We report long-term real-world outcomes with first-line avelumab + axitinib from the J-DART2 study in Japan.

Methods: J-DART2 was a multicenter, noninterventional, retrospective study examining clinical data from patients with curatively unresectable locally advanced or metastatic RCC who started treatment with first-line avelumab + axitinib in Japan between December 2019 and October 2022.

Development of medical knowledge content for problem-solving competencies through dialogue with the undergraduate medical education community in Japan.

Background: Discrepancies existed between the medical knowledge sections of the Model Core Curriculum for Medical Education (MCC) and the Guidelines for the National Examination for Medical Practitioners (GNEMP) in Japan. These discrepancies have been one of the underlying factors hindering the development of learner-centered medical education in the country. The project team responsible for the 'Problem-Solving' section of the MCC aimed to address discrepancies between the disease lists in the MCC and the GNEMP.

Ruminant stimulating device-associated esophageal obstruction in a Japanese black heifer with acquired esophageal diverticulum.

Esophageal diseases include esophageal obstruction, esophagitis, esophageal stricture, and esophageal diverticulum. Imaging can facilitate the selection of appropriate treatment options and assist in differential diagnosis. Esophageal obstruction in cattle is generally caused by greedy nature of chewing and swallowing of food and foreign structures, including stones, potatoes, trichobezoar, carrots, foodstuffs (i.

Environmental dependence of geometrical efficiency for the scintillation cell in radon and thoron measurement.

222Rn is recognized as a matter of international concern for human health risk. Because 220Rn as well as 222Rn coexist in the natural environment, thoron sometimes influences the experiment for radon measurement. It is important to measure radon and thoron separately to evaluate the risk of the exposure to 222Rn.

Assessment of annual effective doses from indoor radon and thoron in Doi Lo, Chiang Mai, Thailand.

This study aimed to determine the annual effective dose resulting from radon and thoron progeny inhalation. The levels of radon, thoron, and progeny were assessed in residences situated in the Doi Lo region of Chiang Mai, Thailand. Indoor radon and thoron concentrations were detected using passive discriminative detectors.

Behavior of radioactive cesium concentration for 13 years after FDNPP accident at Koriyama campus of Nihon University, Fukushima, Japan.

The concentration of the radioactive cesium (134Cs and 137Cs) in soils and in atmospheric fallouts has been measured at the Koriyama campus, Nihon University, after the Fukushima Dai-ichi Nuclear Power Plant accident for 13 y, from October 2011 till September 2023 and now ongoing. The concentration of them decreased very rapidly due to decontamination activities and weathering effects, with an environmental half-life of 1.21 and 2.

Development of evaluation method for radiocesium availability in soil by biomimetic approach.

Applicability of biomimetic approach with simulation of plant uptake for assessment of radiocesium availability in soil was investigated. The soil spiked with 137Cs tracer was contacted with wicking material and copper-substituted prussian blue (Cu-PB), which simulate transpirationally induced mass flow and concentration gradient-induced diffusion of radiocesiumin the soil, respectively. Comparison of the removed 137Cs to the wick and the wick + Cu-PB from the soil during the contact period of 12 weeks suggested that the diffusion process has larger contribution than the mass flow process in radiocesium dynamics in root zone.

Chemical form of volatilized iodine obtained from orchard grass (Dactylis glomerata L.).

Japan's first commercial nuclear fuel reprocessing plant is expected to release radioiodine into the atmosphere, and orchard grass plants grown in the vicinity of this plant may absorb this radioiodine. In this study, we investigated the mechanism underlying the absorption and volatilization of iodine in the leaves of orchard grass. Our findings suggest that iodine can be transferred from the leaves of this grass to the atmosphere via two routes: direct volatilization and absorption followed by volatilization.

Absorption and translocation to fruit for cesium applied on apple tree leaf surface.

We investigated the behavior of stable Cs+ ions contained in droplets applied directly on the leaf surfaces of plumleaf crab apple trees (2-3 years old Malus domestica 'Alps Otome') at three different fruit growing stages: before bearing fruit, early fruit development and late fruit development stages. Most of the Cs was rapidly transferred from the leaf surfaces into the applied leaves after application, and then gradually transferred to the fruit through the branches. The mean proportion of Cs transferred to fruit by harvest time ranged from 11 to 30% not directly depending on the fruit growing stages.

Practical cut-off value for radon concentration in indoor air using an activated-charcoal radon collector.

The World Health Organization (WHO) recommends that countries adopt the reference level of 100 Bq m-3 for indoor radon gas. Adopting the reference level requires a preliminary assessment of the indoor radon concentration. In the preliminary investigation, a cut-off value is useful, which is a value for selecting samples that can be reliably determined to be below the reference level (in this paper, the WHO reference level) using a straightforward method.

Assessment of air dose distribution in the vertical plane for better occupational exposure management.

The International Commission on Radiological Protection recommended a significant reduction of the equivalent dose limit for the eye lens. Reportedly, medical staff in charge of diagnostic imaging procedures may exceed the new dose limits for the eye lens. The use of dosimeters dedicated to the eye lens remains low, and dosimeters for the neck region were often used to assess eye lens doses.

Study of seasonal variation of accident-derived atmospheric radiocesium in Koriyama City, Fukushima Prefecture, Japan during 2011-2014.

This study measured the atmospheric concentration and deposition flux of radiocesium in Koriyama City, Fukushima Prefecture, Japan, from November 2011 to October 2014. The results show synchronous seasonal change in atmospheric concentration and deposition flux of radiocesium, which is high during winter to early spring and low during summer to autumn. These seasonal variations are similar to those observed in Fukushima City but differ from those in Namie Town, Fukushima Prefecture, comprising a larger contaminated forest area.

Evaluation of combustion system for organically bound tritium analysis using dried fish samples.

The combustion process of the organically bound tritium (OBT) analysis method is difficult and requires sophisticated techniques. For ease, safety, and reproducibility a semi-automatic combustion system was developed. An arbitrary combustion program that prevents sudden ignition was devised and combustion tests were conducted.

Involvement of cellular senescence in the effect of X-irradiated human lung fibroblast WI-38 cells on human lung cancer A549 cell clonogenic potential.

Ionizing radiation not only affects irradiated but also non-irradiated surrounding cells through intercellular communication, indicating that the former cells could affect the latter. The present study investigated the effect of X-irradiated normal human lung fibroblast WI-38 cells on the clonofenic potential of human lung cancer A549 cells by co-culturing them. Moreover, the relationship between the effects of co-culturing on the clonogenic potential of A549 cells and cellular senescence in WI-38 cells was investigated.

Evaluation of an ionization chamber characteristics for 222Rn calibration.

The National Metrology Institute of Japan plan to use an inner-through-type ionization chamber (IC) as a working standard to calibrate radon monitors. Novel methods to calibrate the IC were described, and the calibration factor, CF [Bq m -3 A-1], of the IC with its expanded uncertainty (k = 2) was evaluated to be (2.0 ± 0.

Radiation dose estimation for indoor radon, thoron and their progenies using a stochastic method-a small-scale survey in Wuhan, China.

Passive radon monitors with CR-39s are widely used in major epidemiological surveys. However, the conventional CR-39 track density determining strategy makes it difficult to accurately estimate the concentration because of the heterogeneity of tracks on CR-39s. This study introduced a stochastic method, Latin hypercube sampling, to improve the track density determining strategy and provide the probability distribution of 222Rn concentration and equilibrium equivalent thoron concentration.

Effect of sampling face velocity on the ultrafine particle surface collection efficiency of a cellulose membrane filter and a cellulose-glass fiber filter for environmental airborne radioactivity monitoring.

Surface collection efficiency (SCE) of a cellulose membrane filter (CMF) and a cellulose-glass fiber filter used in environmental monitoring for alpha-emitting radionuclides from nuclear facilities and natural radioactivity sources was evaluated for particles in the size range of 0.03-0.1 μm at different levels of face velocity.

Tritium concentration in monthly precipitation in Okinawa and Kagoshima, southern Japan.

This study aimed at understanding the background concentration level of tritium in precipitation in southern Japan, where precipitation samples were collected monthly in 2022 in Okinawa and Kagoshima. Tritium concentration in monthly precipitation collected in Okinawa since 2014 ranged from 0.05 to 0.

Possible existence of dose-rate threshold for mutation induction by chronic low-dose-rate gamma-rays.

To assess the biological effects of low-dose and low-dose-rate radiation, we established a sensitive assay system for detecting somatic mutations in hypoxanthine-phosphoribosyltransferase 1 (HPRT1) gene. In this study, we investigated the dose-rate effects of mutagenesis by gamma irradiation at dose-rates of 6.6, 20 and 200 mGy d-1.

Impacts of the large fusion test facility on tritium in environmental water and natural radiation levels.

In the progress of nuclear fusion development, environmental radiation monitoring in the vicinity of the facility would be an important issue. At the National Institute of Fusion Science (NIFS), the deuterium plasma experiment, which produces tritium and neutrons using d-d fusion reactions, was conducted from 2017 to 2022. Environmental radiation and tritium in environmental water were monitored before and during the deuterium plasma experiment for public acceptance.