174 results match your criteria: "Research Center for Nuclear Physics[Affiliation]"
Geriatr Gerontol Int
January 2025
Health and Counselling Center, Osaka University, Osaka, Japan.
Aim: The aim of this study was to investigate the relationship between preoperative patient factors and postoperative half-year health care utilization reflecting recovery, common complications, comorbidities, and significant health concerns, identifying strong risk and protective factors.
Methods: This retrospective cohort study utilized linear, quantile, and ordinal regressions to analyze Osaka National Health Insurance data from 26 606 elderly patients who underwent hip fracture surgery between 2012 and 2018.
Results: The key factors associated with multiple postoperative care utilizations (P < 0.
JMIR Form Res
January 2025
Center for Infectious Disease Education and Research, Osaka University, Co-creation BLDG. D88-1, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan, 81 50-5604-3730.
Background: The COVID-19 pandemic has caused serious health, economic, and social consequences worldwide. Understanding how infectious diseases spread can help mitigate these impacts. The Theil index, a measure of inequality rooted in information theory, is useful for identifying geographic disproportionality in COVID-19 incidence across regions.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan.
Dipole toroidal modes appear in many fields of physics. In nuclei, such a mode was predicted more than 50 years ago, but clear experimental evidence was lacking so far. Using a combination of high-resolution inelastic scattering experiments with photons, electrons, and protons, we identify for the first time candidates for toroidal dipole excitations in the nucleus ^{58}Ni and demonstrate that transverse electron scattering form factors represent a relevant experimental observable to prove their nature.
View Article and Find Full Text PDFJ Environ Radioact
December 2024
Graduate School of Human Environment, Osaka Sangyo University, Osaka, 5748530, Japan.
Tritium, a radioactive isotope produced naturally through cosmic radiation interactions and anthropogenically through nuclear weapons testing, poses potential environmental risks, particularly within the water cycle. This study measured tritium concentrations in surface water across Thailand to establish a baseline dataset for monitoring potential contamination from nuclear activities and accidents. Surface water samples were collected from 14 large reservoirs during the wet season in October 2023 and the dry season in February 2024, providing a total of 28 samples.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Using the Bρ-defined isochronous mass spectrometry technique, we report the first determination of the ^{23}Si, ^{26}P, ^{27}S, and ^{31}Ar masses and improve the precision of the ^{28}S mass by a factor of 11. Our measurements confirm that these isotopes are bound and fix the location of the proton dripline in P, S, and Ar. We find that the mirror energy differences of the mirror-nuclei pairs ^{26}P-^{26}Na, ^{27}P-^{27}Mg, ^{27}S-^{27}Na, ^{28}S-^{28}Mg, and ^{31}Ar-^{31}Al deviate significantly from the values predicted assuming mirror symmetry.
View Article and Find Full Text PDFInteractions (Cham)
March 2024
Institute of Physics, The University of Tokyo, Komaba, Meguro-ku, 153-8902 Tokyo Japan.
We have developed a microwave spectrometer for a measurement of the Lamb shift of antihydrogen atoms towards the determination of the antiproton charge radius. The spectrometer consists of two consecutive apparatuses, of which the first apparatus, (HFS), filters out hyperfine states and pre-selects the state, and the second apparatus, (MWS), sweeps the frequency around the target transition to obtain the spectrum. We optimized the geometry of the apparatuses by evaluating the S-parameter that represents the ratio of the reflected microwave signal over the input, utilizing microwave simulations based on the finite element method.
View Article and Find Full Text PDFRadiat Prot Dosimetry
November 2024
Aloka Co., Ltd., Tokyo 198-0023, Japan.
This study aimed to measure tritium (3H) concentrations in Thailand. Nationwide tap water samples were collected in July 2021. Rainwater samples were collected monthly during May-October 2020, April-October 2021, and February-March 2022 in Chonburi province and in Chiang Mai province during July-November 2021, January 2022, and March-June 2022.
View Article and Find Full Text PDFInt J Radiat Biol
October 2024
Professor Emeritus, Division of Safety Management, Radioisotope Research Center, Osaka University, Osaka, Japan.
To quantitatively investigate the effects of chronic low-dose internal exposure to Cesium-137 on DNA damage, carcinogenicity, and offspring over multiple generations. The potential genetic risk in humans was predicted based on next-generation murine mutation rates to confirm the reasonableness of the current Cesium-137 dose limits for food. Cesium-137 (100 Bq/mL) was provided in drinking water to A/J mice, facilitating chronic, low-dose, low-dose-rate internal exposure through sibling mating over 25 generations (G25).
View Article and Find Full Text PDFPhys Rev Lett
August 2024
Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong, China.
Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low excitation energies, 985.3(19) keV in ^{213}Tl and 874(5) keV in ^{215}Tl.
View Article and Find Full Text PDFMed Phys
October 2024
Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA.
Background: Phenomenological relative biological effectiveness (RBE) models for proton therapy, based on the dose-averaged linear energy transfer (LET), have been developed to address the apparent RBE increase towards the end of the proton range. The results of these phenomenological models substantially differ due to varying empirical assumptions and fitting functions. In contrast, more theory-based approaches are used in carbon ion radiotherapy, such as the microdosimetric kinetic model (MKM).
View Article and Find Full Text PDFPhys Rev Lett
July 2024
RIKEN Nishina Center, Wako 351-0198, Japan.
To search for low-energy resonant structures in isospin T=3/2 three-body systems, we have performed the experiments ^{3}H(t,^{3}He)3n and ^{3}He(^{3}He,t)3p at intermediate energies. For the 3n experiment, we have newly developed a thick Ti-^{3}H target that has the largest tritium thickness among targets of this type ever made. The 3n experiment for the first time covered the momentum-transfer region as low as 15 MeV/c, which provides ideal conditions for producing fragile systems.
View Article and Find Full Text PDFJ Radiat Res
July 2024
Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Iwado-kita 2-11-1, Komae, Tokyo 201-8511, Japan.
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.
View Article and Find Full Text PDFRev Sci Instrum
June 2024
Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan.
Producing a polarized lanthanum (La) target with high polarization and long relaxation time is crucial for realizing time-reversal violation experiments using polarized neutron beams. We use a LaAlO3 crystal doped with a small amount of Nd3+ ions for the polarized lanthanum target. Optimizing the amount of Nd3+ ions is considerably important because the achievable polarization and relaxation time strongly depend on this amount.
View Article and Find Full Text PDFSci Bull (Beijing)
June 2024
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt D-64291, Germany.
We report the charge-changing cross sections (σ) of 24 p-shell nuclides on both hydrogen and carbon at about 900A MeV, of which Li, Be, B, N and O on hydrogen and Li on carbon are for the first time. Benefiting from the data set, we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets. This allows us to deduce proton radii (R) for the first time from the cross sections on hydrogen.
View Article and Find Full Text PDFRev Sci Instrum
March 2024
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Solid-state nuclear track detectors (SSNTDs) are often used as ion detectors in laser-driven ion acceleration experiments and are considered to be the most reliable ion diagnostics since they are sensitive only to ions and measure ions one by one. However, ion pit analyses require tremendous time and effort in chemical etching, microscope scanning, and ion pit identification by eyes. From a laser-driven ion acceleration experiment, there are typically millions of microscopic images, and it is practically impossible to analyze all of them by hand.
View Article and Find Full Text PDFPhys Rev Lett
January 2024
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
With excellent energy resolution and ultralow-level radiogenic backgrounds, the high-purity germanium detectors in the Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via the transition magnetic moment from conversion to active neutrinos ν_{s}→ν_{a}. We report new limits on fermionic dark matter absorption (χ+A→ν+A) and sub-GeV DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), and new exclusion limits for bosonic dark matter (axionlike particles and dark photons).
View Article and Find Full Text PDFEnviron Health Prev Med
January 2024
Health Care Division, Health and Counseling Center, Osaka University.
Background: It is crucial to understand the seasonal variation of Metabolic Syndrome (MetS) for the detection and management of MetS. Previous studies have demonstrated the seasonal variations in MetS prevalence and its markers, but their methods are not robust. To clarify the concrete seasonal variations in the MetS prevalence and its markers, we utilized a powerful method called Seasonal Trend Decomposition Procedure based on LOESS (STL) and a big dataset of health checkups.
View Article and Find Full Text PDFNat Commun
December 2023
College of Science and Engineering, Kanto Gakuin University, Yokohama, 236-8501, Japan.
The formed He (α) clusters consisting of two neutrons and two protons can be a building block in light nuclear systems. Intriguingly, these alpha clusters could potentially form alpha condensate states within the nuclear system. The Hoyle state at 7.
View Article and Find Full Text PDFPhys Rev Lett
November 2023
Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8551, Japan.
The cluster structure of the neutron-rich isotope ^{10}Be has been probed via the (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and in quasifree conditions. The populated states of ^{6}He residues were investigated through missing mass spectroscopy. The triple differential cross section for the ground-state transition was extracted for quasifree angle pairs (θ_{p},θ_{α}) and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using successively the Tohsaki-Horiuchi-Schuck-Röpke product wave function and the wave function deduced from antisymmetrized molecular dynamics calculations.
View Article and Find Full Text PDFNature
November 2023
Liberal and General Education Center, Institute for Promotion of Higher Academic Education, Utsunomiya University, Tochigi, Japan.
Rev Sci Instrum
June 2023
Research Center for the Early Universe, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
A half-wave plate (HWP) is often used as a modulator to suppress systematic error in the measurements of cosmic microwave background (CMB) polarization. A HWP can also be used to measure circular polarization (CP) through its optical leakage from CP to linear polarization. The CP of the CMB is predicted from various sources, such as interactions in the Universe and extension of the standard model.
View Article and Find Full Text PDFNature
August 2023
Liberal and General Education Center, Institute for Promotion of Higher Academic Education, Utsunomiya University, Tochigi, Japan.
Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10 s), provide the most stringent tests of modern nuclear-structure theories.
View Article and Find Full Text PDFPhys Med Biol
July 2023
Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States of America.
. Estimation of the probability density of the microdosimetric quantities in macroscopic matter is indispensable for applying the concept of microdosimetry to medical physics and radiological protection. The Particle and Heavy Ion Transport code System (PHITS) enables estimating the microdosimetric probability densities due to its unique hybrid modality between the Monte Carlo and analytical approaches called the microdosimetric function.
View Article and Find Full Text PDFPhys Rev Lett
April 2023
RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient ^{14}O nucleus with large Fermi-surface asymmetry S_{n}-S_{p}=18.6 MeV at ∼100 MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the ^{13}N and ^{13}O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations.
View Article and Find Full Text PDFInt J Mol Sci
April 2023
Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL 60660, USA.
New carborane-bearing hydroxamate matrix metalloproteinase (MMP) ligands have been synthesized for boron neutron capture therapy (BNCT) with nanomolar potency against MMP-2, -9 and -13. New analogs are based on MMP inhibitor CGS-23023A, and two previously reported MMP ligands () and () were studied in vitro for BNCT activity. The boronated MMP ligands and showed high in vitro tumoricidal effects in an in vitro BNCT assay, exhibiting IC values for and of 2.
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