National Institutes for Quantum and Radiological Science and Technology
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SALMON VR: Visualizing Light–Matter Dynamics
No full textThis study presents SALMON VR, a visualization program designed to visualize the time evolution of electronic density changes and vector potentials in virtual reality (VR) space. The time-series electronic density data computed by SALMON are stored in CUBE format. SALMON VR processes these data to construct isosurfaces of electronic density variations and two-dimensional representations of vector potentials. Equipped with a user-friendly interface using VR technology, the program is available in two versions: one for the Meta Quest 3 head-mount display (Meta Platforms Inc., California) and one for PCs. Atoms are displayed as spheres of different sizes and colors according to their elemental properties. This visual representation facilitates a deeper understanding of the complex interactions between light and electrons. Users can easily manipulate the isosurface values, speed of animation, and color map of the vector potential. SALMON VR will enable researchers and educators to enhance their understanding of physical phenomena and improve engagement in learning environments.journal articl
Uranium micro localization in the renal proximal tubules during intimal exposure of rats to uranyl acetate
No full textThe kidney is the main site of deposition of uranium (U) after exposure. The distal portion of the proximal tubules (S3 segment) are thought to be responsible for the reabsorption of U from the urine, but the dynamics of U distribution in the renal tubules has not been clearly understood. In the present study, the precise distribution of U in the S3 segment of the proximal tubules (S3 tubules) was examined in Wistar male rats during the initial phase of subcutaneous U administration (1 to 3 h post-administration of uranyl acetate, 0.5 mg/kg of body weight) by X-ray fluorescence spectrometry using high energy synchrotron radiation microbeam (SR-μXRF). At 1 h post-administration, rapid transition of U into kidney was observed; U was accumulated in the kidneys at the level of 4% of the dose. In the cross-section of the S3 tubules, U was distributed in the brush border, indicated that U was already being reabsorbed from the urine at this point. Formation of highly concentrated U in microregions with the maximum U level of around 150 μg/g was also detected in the epithelium of the S3 tubules. At 3 h post-administration, the amount of U accumulated to the kidneys was 9% of the dose, and the maximum uranium level of the micro localization in the epithelium of the S3 tubules reached above 200 μg/g. The distribution pattern of micro localization was characteristic of U and differed from those of endogenous trace elements, such as iron and zinc. These findings would be valuable information for decrporation strategies of accumulated U from the critical organ.journal articl
宇宙環境における電荷・LET依存線質係数と固体飛跡検出器を組み合わせた線量評価手法
No full text宇宙放射線は高エネルギーの重荷電粒子が主要成分であり、これらの線量評価には線質係数QICRPが慣例的に用いられている。一方で、QICRPは同LETで電荷の異なる粒子による飛跡構造の差が考慮されておらず、これによる被ばく量の過大評価が指摘されている。粒子の飛跡構造を考慮した線質係数QNASAが提案されているものの、電荷とLETを変数としており、これを現行の固体飛跡検出器を用いた重粒子線量評価に適応するのは困難である。本研究では、太陽活動と遮蔽厚さによる銀河宇宙線環境の差を考慮し、現行手法にそのまま適応可能な電荷荷重線質係数Q*を提案する。第38回固体飛跡検出器研究会conference presentatio
Benchmarking Monte Carlo codes for the modelling of low-energy neutron production target reactions
No full textThe increasing adoption of accelerator-based neutron sources (ABNS) for applications including neutron capture therapy (NCT) research has highlighted the need for accurate simulation tools. Precise modelling of the neutron production target is crucial to ensure that simulated predictions of neutron beam characteristics used for subsequent beam shaping assembly design are reliable. This work presents a comprehensive benchmarking of four widely-used Monte Carlo codes - Geant4, PHITS, FLUKA (CERN), and MCNP - for modelling low-energy neutron production target reactions. Using their recommended physics models and cross-section libraries, we evaluate each code’s performance in simulating four beam-target reactions: 7Li(p,n)7Be, 9Be(p,n)9B, 9Be(d,n)10B, and C(d,n)N. Predictions of neutron yield, angular distributions, and energy spectra are compared against available thick target experimental data. Results show varying levels of agreement between the codes depending on the reaction type, energy range, and beam characteristics. Geant4, MCNP and PHITS are the overall best performing codes for the simulation of total neutron yield and yield in the forward direction across most reactions. Across energies where experimental benchmarks exist, inter-code discrepancies in total and forward-directed yield are typically 10 to 30%, with larger deviations at near-threshold incident ion energies. PHITS provides the best overall reproduction of experimental spectra, particularly for the 9Be(p,n)9B reaction. Additionally, PHITS demonstrates superior computational performance for most reactions. These findings provide valuable guidance for ABNS design, highlighting the strengths and limitations of each code for the simulation of low-energy neutron production reactions.journal articl
A novel small molecule that enhances lysyl hydroxylase 2 activity and matrix mineralization
No full textLysyl hydroxylase 2 (LH2), encoded by the procollagen lysine 2-oxoglutarate 5-dioxygenase 2 (Plod2) gene, catalyzes the hydroxylation of lysine residues in the fibrillar collagen telopeptides. This post-translational modification is essential for forming the stable hydroxylysine-aldehyde derived collagen cross-links that play a critical role in collagen stability, mechanical strength, and bone formation. Defective LH2 activities have been implicated in bone disorders including Bruck syndrome, however, effective agents that control LH2 activity have not been developed until now. In this study, using in silico docking simulations, we identified a small molecule (KS122-0485428) that specifically binds LH2, and assessed the effects of this compound on collagen cross-linking, cell proliferation, and mineralization using the murine osteoblastic cell line MC3T3-E1. While KS122-0485428 did not affect cell proliferation and LH2 expression, it significantly accelerated mineralization. The hydroxylysine-aldehyde derived collagen cross-links were also significantly increased at the expense of the lysine-aldehyde derived cross-link. These results demonstrate that KS122-0485428 enhances LH2 activity leading to accelerated mineralization. Thus, this novel LH2 activator has the potential as a therapeutic agent for bone repair and regeneration.journal articl
レーザービームプロファイル画像の深層学習による光学系損傷の自動検査技術
No full text本研究では，Xceptionによる深層特徴抽出と，SPADE による教師なし異常検知を組み合わせることで，レーザービームプロファイル画像から光学系の損傷を自動で検査出来ることを確認した．本システムは学習する画像を増加することで更に高精度化し，高強度レーザーの安定運用に大きく貢献することが期待される．一般社団法人レーザー学会学術講演会第46回年次大会conference presentatio
The 2024 NIA-AA biological definition of Alzheimer’s disease: linking biomarkers to clinical practice
No full textThe 2024 National Institute on Aging–Alzheimer’s Association (NIA-AA) criteria establish a biological definition of Alzheimer’s disease (AD), marking a pivotal step toward linking research biomarkers with clinical practice. This review traces the evolution of AD diagnostic frameworks from the 1984 NINCDS-ADRDA clinical criteria, through biomarker-informed updates in 2011, to the 2024 biology-based criteria that bridge research and clinical care. The 2024 framework defines AD by its underlying pathology rather than clinical symptoms, recognizing that biomarker evidence alone can establish diagnosis. It expands the traditional AT (N) model into a multimodal profile (AT1T2NISV), in which Core-1 biomarkers (A and T1) are diagnostic, while Core-2 biomarkers (T2) support biological staging. Non-specific but mechanistically important processes (N, neurodegeneration; I, inflammation) and common co-pathologies (S, α-synuclein; V, vascular injury) are also incorporated to better capture the complexity of late-life dementia. Recent advances in plasma and PET biomarkers, including p-tau217, mid-region p-tau, and α-synuclein imaging, are redefining biological diagnosis and expanding its reach. Moreover, co-pathologies involving TDP-43, glial dysfunction, and vascular factors contribute to disease heterogeneity and variable therapeutic response. While the 2024 criteria represent a major conceptual step forward, they should be regarded as a dynamic framework open to future integration of emerging biomarkers. Bridging molecular pathology, neuroimaging, and clinical presentation will be essential to realize the goal of patient-centered precision medicine in AD. In this review, we synthesize recent advances in biomarker-based frameworks for AD and discuss co-pathologies, resilience-related modifiers, and emerging evidence challenging traditional interpretations of structural neurodegeneration markers. We also address implications for clinical implementation, including PET standardization and disease-modifying therapies.journal articl
Carbon-Ion radiotherapy alone for inoperable locally advanced Non-Small cell lung cancer: A Japanese National registry study (J-CROS-LUNG)
No full textPurposeCarbon-ion radiotherapy (CIRT) offers high-dose concentration and enhanced biological effects. Since 2016, a nationwide prospective registry study of CIRT for locally advanced non-small cell lung cancer (LA-NSCLC) has been conducted in Japan. This study aimed to evaluate clinical outcomes of CIRT in patients with LA-NSCLC who were ineligible for surgery or chemoradiotherapy (CCRT).Materials and methodsPatients with inoperable LA-NSCLC treated with CIRT in Japan from May 2016 to June 2020 were included. Most patients received 64–72 Gy in 16 fractions per the Japanese Society for Radiation Oncology (JASTRO) unified policy. Elective nodal irradiation was allowed for nodal disease. No systemic therapy was administered before or after CIRT. Overall and progression-free survival were estimated by the Kaplan–Meier method; local failure was evaluated using the cumulative incidence function (CIF) with Gray’s test. Two-sided P < 0.05 was considered significant.ResultsMedian follow-up was 28 months for all patients and 36 months for survivors. Of the 55 patients, clinical stages (UICC 8th) were: IIB (26), IIIA (17), and IIIB (12). A clinical diagnosis without histological confirmation was established in four patients (7.3%), and interstitial pneumonia (IP) was present in nine (16.4%). The 3-year overall survival and progression-free survival were 49.1% (95% confidence interval [CI], 33.8–62.7%) and 28.3% (95% CI, 16.6–41.3%), respectively. Using competing risks, the 3-year CIF was 37.4% (95% CI, 24.2–50.5%). No grade ≥ 4 toxicity was observed; grade 2 and 3 pneumonitis occurred in 3 (5.5%) and 2 (3.6%) patients, respectively. In multivariable analysis, concomitant IP was a significant factor for overall survival (P = 0.011).ConclusionCIRT demonstrated favorable tumor control with acceptable toxicity in patients with LA-NSCLC ineligible for surgery or CCRT. It may be a promising treatment option for this patient population.journal articl
Ultra-dense lutetium oxide ceramic scintillators for positron emission tomography
No full textObjective. Lutetium oxide (Lu2O3), with its high density (9.4 g cm−3), presents a compelling scintillation host for detecting 511 keV annihilation photons in positron emission tomography (PET). Despite its favorable density, the practical deployment of Lu2O3-based scintillators for PET has faced limitations due to difficulties in crystal growth and inappropriate decay time. Recent progress in ceramic processing has facilitated the development of transparent Lu2O3 ceramics, while targeted doping strategies have significantly improved their luminescence performance. This study evaluates the performance of Lu2O3:Yb and a newly developed ceramic scintillator of (Lu,Y)2O3:La, a modified Lu2O3-based compound incorporating yttrium (Y) and doped with lanthanum (La). Approach. Various ceramic disks were fabricated and cut into 3 × 3 × 5 mm3 samples. The performance of both Lu2O3:Yb and (Lu,Y)2O3:La ceramic samples in terms of decay time, energy resolution, and coincidence timing resolution (CTR) was assessed. Decay time measurements were conducted using waveform data collected from samples mounted on an H10580 photomultiplier tube (PMT) and irradiated with 511 keV photons from a 22Na source. Energy and CTRs were evaluated using both PMT and silicon photomultiplier setups, arranged in coincidence with a reference lutetium–yttrium oxyorthosilicate (LYSO) detector of the same size. Main results. All three (Lu,Y)2O3:La ceramic scintillator samples exhibited a triple exponential decay profile and were dominated by a slow component ranging from 1379.3 to 1515.6 ns. The best energy resolution of 15.4% at 511 keV and the best CTR of 237.9 ps full width at half maximum (FWHM) were observed for the same sample. In contrast, a fast decay time of 1.6 ns was observed for the Lu2O3:Yb samples, which exhibited CTR values ranging from 237.9 ps to 261.4 ps FWHM, while the photopeak at 511 keV was difficult to distinguish. These CTR values were estimated between two identical ceramic samples, derived from coincidence measurements of each ceramic sample against the LYSO reference detector. The (Lu,Y)2O3:La samples achieved CTR values comparable to those of the Lu2O3:Yb samples, as their much higher light yield offsets the disadvantage associated with their slower decay time. Significance. These results highlight the promising potential of the (Lu,Y)2O3:La ceramic scintillators for PET applications, especially for time-of-flight PET.journal articl
2025年度生体分子機能科学集中講義
No full text生体に関連するラジカルの反応および機能を明らかにする。活性種の生体成分との反応を明らかにし、その防御機構および防御物質についても考察する。2025年度生体分子機能科学集中講義conference presentatio