Prediction of key biological processes from intercellular DNA damage differences through model-based fitting.

DNA double-strand breaks (DSBs) occurring within the genomic DNA of mammalian cells significantly impact cell survival, depending upon their repair capacity. This study presents a mathematical model to fit fibroblast survival rates with a sequence-specific DSB burden induced by the restriction enzyme AsiSI. When cells had a sporadic DSB burden under mixed culture, cell growth showed a good fit to the Lotka-Volterra competitive equation, predicting the presence of modifying factors acting as competitive cell-to-cell interactions compared to monocultures.

Testicular exposure to ionizing radiation and sperm epigenetic alterations as possible mechanisms of hereditary effects: perspectives from the viewpoint of radiation protection.

Purpose: Since the genotoxicity of ionizing radiation was demonstrated in the 1920s, its hereditary effects have remained a serious concern for human society. The International Commission on Radiological Protection has highlighted the need for appropriate protection against hereditary effects of radiation in humans. In this paper, we review the literature on the possible multigenerational and transgenerational effects following testicular exposure to radiation, focusing on sperm epigenetic alterations as possible mechanisms.

MeCP2 deficiency leads to the γH2AX nano foci expansion after ionizing radiation.

DNA double-strand breaks (DSBs) trigger the recruitment of repair protein and promote signal transduction through posttranslational modifications such as phosphorylation. After DSB induction, ataxia telangiectasia mutated (ATM) phosphorylates H2AX on chromatin surrounds the mega-base pairs proximal to the DSBs. Advanced super-resolution microscopic technology has demonstrated the formation of γH2AX nano foci as a unit of nano domain comprised of multiple nucleosomes.

Electrically induced insulator-to-metal transition in InP-based ion-gated transistor.

With the growing awareness of energy savings and consumption for a sustainable ecosystem, the concept of iontronics, that is, controlling electronic devices with ions, has become critically important. Composite devices made of ions and solid materials have been investigated for diverse applications, ranging from energy storage to power generation, memory, biomimetics, and neuromorphic devices. In these studies, three terminal transistor configurations with liquid electrolytes have often been utilized because of their simple device structures and relatively easy fabrication processes.

Immobilisation of iodide in alkali-activated materials.

At the Fukushima Daiichi Nuclear Power Station (FDNPS), continuous water circulation cools fuel debris, leading to the presence of radionuclides such as Sr-30, Cs-137, and I-129 in the cooling water. These radionuclides are adsorbed and co-precipitated by various materials. Among them, I-129 is a key radionuclide for safety assessment during the final disposal of adsorbent and co-precipitation materials, owing to its long half-life and poor sorption.

Mechanisms Underlying Sensory Nerve-Predominant Damage by Methylmercury in the Peripheral Nervous System.

Sensory disturbances and central nervous system symptoms are important in patients with Minamata disease. In the peripheral nervous system of these patients, motor nerves are not strongly injured, whereas sensory nerves are predominantly affected. In this study, we investigated the mechanisms underlying the sensory-predominant impairment of the peripheral nervous system caused by methylmercury.

AOP Report: Development of an adverse outcome pathway for deposition of energy leading to bone loss.

Bone loss, commonly seen in osteoporosis, is a condition that entails a progressive decline of bone mineral density and microarchitecture, often seen in post-menopausal women. Bone loss has also been widely reported in astronauts exposed to a plethora of stressors and in patients with osteoporosis following radiotherapy for cancer. Studies on mechanisms are well documented but the causal connectivity of events to bone loss development remains incompletely understood.

Hidden gems: Scattered knowledge hampered freshwater jellyfish research over the past one-and-a-half centuries.

Freshwater jellyfish (= limnic medusa-budding hydrozoans, FWJ) are a small group of cnidarians found on all continents except Antarctica in temperate to tropical latitudes. Members of this group belong primarily to three genera: , , and . While and are typically restricted to the islands of Japan, Africa, and the Indian subcontinent, one species or potential species complex, , became globally invasive.

Athyrium yokoscense, a cadmium-hypertolerant fern, exhibits two cadmium stress mitigation strategies in its roots and aerial parts.

Athyrium yokoscense is hypertolerant to cadmium (Cd) and can grow normally under a high Cd concentration despite Cd being a highly toxic heavy metal. To mitigate Cd stress in general plant species, Cd is promptly chelated with a thiol compound and is isolated into vacuoles. Generated active oxygen species (ROS) in the cytoplasm are removed by reduced glutathione.

Stimulus effects of extremely low-frequency electric field exposure on calcium oscillations in a human cortical spheroid.

High-intensity, low-frequency (1 Hz to 100 kHz) electric and magnetic fields (EF and MF) cause electrical excitation of the nervous system via an induced EF (iEF) in living tissue. However, the biological properties and thresholds of stimulus effects on synchronized activity in a three-dimensional (3D) neuronal network remain uncertain. In this study, we evaluated changes in neuronal network activity during extremely low-frequency EF (ELF-EF) exposure by measuring intracellular calcium ([Ca]) oscillations, which reflect neuronal network activity.

Improving the estimation of direct release rates and transport processes from the Fukushima Daiichi Nuclear Power Plant accident using higher-resolution oceanic dispersion model.

A series of accidents at the Fukushima Daiichi Nuclear Power Station (F1NPS), following the 11 March 2011 earthquake and tsunami, resulted in the release of radioactive substances into the ocean. In particular, the release of large amounts of radioactive caesium has damaged the fishing industry, leading to voluntary restrictions on fishing and shipping. Oceanic dispersion simulations based on estimates of the pathways and fluxes of radioactive materials provide useful information for assessing the environmental impacts and formulating measures to mitigate the effects of the accident.

A Historical Survey of Key Epidemiological Studies of Ionizing Radiation Exposure.

In this article we review the history of key epidemiological studies of populations exposed to ionizing radiation. We highlight historical and recent findings regarding radiation-associated risks for incidence and mortality of cancer and non-cancer outcomes with emphasis on study design and methods of exposure assessment and dose estimation along with brief consideration of sources of bias for a few of the more important studies. We examine the findings from the epidemiological studies of the Japanese atomic bomb survivors, persons exposed to radiation for diagnostic or therapeutic purposes, those exposed to environmental sources including Chornobyl and other reactor accidents, and occupationally exposed cohorts.

Establishment and activity of the planning and acting network for low dose radiation research in Japan (PLANET): 2016-2023.

The Planning and Acting Network for Low Dose Radiation Research in Japan (PLANET) was established in 2017 in response to the need for an all-Japan network of experts. It serves as an academic platform to propose strategies and facilitate collaboration to improve quantitative estimation of health risks from ionizing radiation at low-doses and low-dose-rates. PLANET established Working Group 1 (Dose-Rate Effects in Animal Experiments) to consolidate findings from animal experiments on dose-rate effects in carcinogenesis.

Feasibility of I groundwater dating calibrated by both Kr and He for the assessment of deep geological repositories in Japan.

Iodine-129, which is a promising tracer for dating old groundwater, has been used as a tracer for deep upwelling groundwater. The nuclide is expected to be one of the key factors for site selection for high-level radioactive waste disposal, which is a global societal issue. The pre-anthropogenic I/I ratio for marine iodine is (1.

Evaluation of relative biological effectiveness for diseases of the circulatory system based on microdosimetry.

In the next decade, the International Commission on Radiological Protection (ICRP) will issue the next set of general recommendations, for which evaluation of relative biological effectiveness (RBE) for various types of tissue reactions would be needed. ICRP has recently classified diseases of the circulatory system (DCS) as a tissue reaction, but has not recommended RBE for DCS. We therefore evaluated the mean and uncertainty of RBE for DCS by applying a microdosimetric kinetic model specialized for RBE estimation of tissue reactions.

Quasi-Non-Destructive Estimation of Concrete Compression Strength Using Laser-Induced Breakdown Spectroscopy and Multivariate Analysis.

Micro- and non-destructive methods of estimating compressive strength are useful for diagnosing the degradation of reinforced structures. The velocity of waves propagating through concrete can be measured using conventional non-destructive methods; however, the propagation path of waves varies depending on the distribution of coarse aggregate, resulting in variations in velocity at different measurement points. To address this issue, a method based on laser-induced breakdown spectroscopy and multivariate analysis was developed in this study for estimating the compressive strength of concrete non-destructively, ensuring the non-influence of the coarse aggregate spatial distribution.

descSPIM: an affordable and easy-to-build light-sheet microscope optimized for tissue clearing techniques.

Despite widespread adoption of tissue clearing techniques in recent years, poor access to suitable light-sheet fluorescence microscopes remains a major obstacle for biomedical end-users. Here, we present descSPIM (desktop-equipped SPIM for cleared specimens), a low-cost ($20,000-50,000), low-expertise (one-day installation by a non-expert), yet practical do-it-yourself light-sheet microscope as a solution for this bottleneck. Even the most fundamental configuration of descSPIM enables multi-color imaging of whole mouse brains and a cancer cell line-derived xenograft tumor mass for the visualization of neurocircuitry, assessment of drug distribution, and pathological examination by false-colored hematoxylin and eosin staining in a three-dimensional manner.

The impact of dose rate on responses of human lens epithelial cells to ionizing irradiation.

The knowledge on responses of human lens epithelial cells (HLECs) to ionizing radiation exposure is important to understand mechanisms of radiation cataracts that are of concern in the field of radiation protection and radiation therapy. However, biological effects in HLECs following protracted exposure have not yet fully been explored. Here, we investigated the temporal kinetics of γ-H2AX foci as a marker for DNA double-strand breaks (DSBs) and cell survival in HLECs after exposure to photon beams at various dose rates (i.

Revisiting an Inverse Dose-Fractionation Effect of Ionizing Radiation Exposure for Ischemic Heart Disease: Insights from Recent Studies.

Over the last two decades, there has been emerging evidence suggesting that ionizing radiation exposures could be associated with elevated risks of cardiovascular disease (CVD), particularly ischemic heart disease (IHD). Excess CVD risks have been observed in a number of exposed groups, with generally similar risk estimates both at low and high radiation doses and dose rates. In 2014, we reported for the first time significantly higher risks of IHD mortality when radiation doses were delivered over a protracted period of time (an inverse dose-fractionation effect) in the Canadian Fluoroscopy Cohort Study.

Radiation Adverse Outcome pathways (AOPs): examining priority questions from an international horizon-style exercise.

Purpose: The Organisation for Economic Co-operation and Development (OECD) Adverse Outcome Pathway (AOP) Development Programme is being explored in the radiation field, as an overarching framework to identify and prioritize research needs that best support strengthening of radiation risk assessment and risk management strategies. To advance the use of AOPs, an international horizon-style exercise (HSE) was initiated through the Radiation/Chemical AOP Joint Topical Group (JTG) formed by the OECD Nuclear Energy Agency (NEA) High-Level Group on Low Dose Research (HLG-LDR) under the auspices of the Committee on Radiological Protection and Public Health (CRPPH). The intent of the HSE was to identify key research questions for consideration in AOP development that would help to reduce uncertainties in estimating the health risks following exposures to low dose and low dose-rate ionizing radiation.

Comparative study of susceptibility to methylmercury cytotoxicity in cell types composing rat peripheral nerves: a higher susceptibility of dorsal root ganglion neurons.

Methylmercury is an environmental polluting organometallic compound that exhibits neurotoxicity, as observed in Minamata disease patients. Methylmercury damages peripheral nerves in Minamata patients, causing more damage to sensory nerves than motor nerves. Peripheral nerves are composed of three cell types: dorsal root ganglion (DRG) cells, anterior horn cells (AHCs), and Schwann cells.