Surface Localization of the Dineutron in ^{11}Li.

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246  MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum.

Clinical evaluation of neuroinflammation in child-onset focal epilepsy: a translocator protein PET study.

Background: Neuroinflammation is associated with various chronic neurological diseases, including epilepsy; however, neuroimaging approaches for visualizing neuroinflammation have not been used in the clinical routine yet. In this study, we used the translocator protein positron emission tomography (PET) with [C] DPA713 to investigate neuroinflammation in the epileptogenic zone in patients with child-onset focal epilepsy.

Methods: Patients with intractable focal epilepsy were recruited at the Epilepsy Center of Osaka University; those who were taking any immunosuppressants or steroids were excluded.

Causal relations of health indices inferred statistically using the DirectLiNGAM algorithm from big data of Osaka prefecture health checkups.

Causal relations among many statistical variables have been assessed using a Linear non-Gaussian Acyclic Model (LiNGAM). Using access to large amounts of health checkup data from Osaka prefecture obtained during the six fiscal years of years 2012-2017, we applied the DirectLiNGAM algorithm as a trial to extract causal relations among health indices for age groups and genders. Results show that LiNGAM yields interesting and reasonable results, suggesting causal relations and correlation among the statistical indices used for these analyses.

α-Emitting cancer therapy using At-AAMT targeting LAT1.

α-Methyl-l-tyrosine (AMT) has a high affinity for the cancer-specific l-type amino acid transporter 1 (LAT1). Therefore, we established an anti-cancer therapy, with At-labeled α-methyl-l-tyrosine ( At-AAMT) as a carrier of At into tumors. At-AAMT had high affinity for LAT1, inhibited tumor cell growth, and induced DNA double-stranded breaks in vitro.

WAM to SeeSaw model for cancer therapy - overcoming LQM difficulties.

Purpose: The assessment of biological effects caused by radiation exposure has been currently carried out with the linear-quadratic (LQ) model as an extension of the linear non-threshold (LNT) model. In this study, we suggest a new mathematical model named as SeaSaw (SS) model, which describes proliferation and cell death effects by taking account of Bergonie-Tribondeau's law in terms of a differential equation in time. We show how this model overcomes the long-standing difficulties of the LQ model.

Novel Indicator to Ascertain the Status and Trend of COVID-19 Spread: Modeling Study.

Background: In the fight against the pandemic of COVID-19, it is important to ascertain the status and trend of the infection spread quickly and accurately.

Objective: The purpose of our study is to formulate a new and simple indicator that represents the COVID-19 spread rate by using publicly available data.

Methods: The new indicator K is a backward difference approximation of the logarithmic derivative of the cumulative number of cases with a time interval of 7 days.

Search for Axionlike Particles Produced in e^{+}e^{-} Collisions at Belle II.

We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e^{+}e^{-}→γa, a→γγ in the mass range 0.2 View Article and Find Full Text PDF

Mapping of a New Deformation Region around ^{62}Ti.

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei.

Monitoring the build-up of hydrogen polarization for polarized hydrogen-deuteride (HD) targets with nuclear magnetic resonance (NMR) at 17 T.

We report on the frozen-spin polarized hydrogen-deuteride (HD) targets for photoproduction experiments at SPring-8/LEPS. Pure HD gas with a small amount of ortho-H (∼0.1%) and a very small amount of para-D (∼0.

Development of high-resolution YAP(Ce) x-ray camera for the imaging of astatine-211(At-211) in small animals.

Purpose: Astatine-211 (At-211) is a promising alpha emitter for radionuclide therapy. High-resolution in vivo imaging of At-211 in small animals is needed for the development of At-211 radiopharmaceuticals. For this purpose, we developed a low-energy x-ray camera using a thin YAlO :Ce (YAP(Ce)) plate to image the low-energy x rays (73-87 keV) from the daughter radionuclide of At-211 (Po-211).

Diagnostic Accuracy of F-PSMA-1007 PET/CT Imaging for Lymph Node Staging of Prostate Carcinoma in Primary and Biochemical Recurrence.

Prostate-specific membrane antigen (PSMA)-ligand PET/CT is performed on patients with prostate cancer to stage the disease initially or to identify sites of recurrence after definitive therapy. On the basis of clinical results, F-PSMA-1007 is a promising PSMA PET tracer, but detailed histologic confirmation has been lacking. Ninety-six patients with prostate cancer underwent F-PSMA-1007 PET/CT followed by either radical prostatectomy with lymphadenectomy or salvage lymphadenectomy.

Automated [F]PSMA-1007 production by a single use cassette-type synthesizer for clinical examination.

Background: [F]PSMA-1007, a positron emission tomography (PET) tracer, specifically targets prostate-specific membrane antigen (PSMA), which is highly expressed in prostate cancer. PSMA-PET is effective especially for regional detection of biochemical recurrence, which significantly affects patient management. Herein, we established and optimized a one-step radiolabeling protocol to separate and purify [F]PSMA-1007 with a CFN-MPS200 synthesizer for clinical application.

Evaluation of D-isomer of F-FBPA for oncology PET focusing on the differentiation of glioma and inflammation.

Objectives: L-4-borono-2-F-fluoro-phenylalanine (L-[F]FBPA), a substrate of L-type amino acid transporter 1 (LAT1), is a tumor-specific probe used in positron emission tomography (PET). On the other hand, it has not been examined whether another isomer D-[F]FBPA accumulates specifically in the tumor. Here, we compared the accumulation of D-[F]FBPA in C6 glioma and inflammation to evaluate the performance of D-[F]FBPA as a tumor-specific probe.

Global Issues of Radiopharmaceutical Access and Availability: A Nuclear Medicine Global Initiative Project.

The Nuclear Medicine Global Initiative was formed in 2012 by 13 international organizations to promote human health by advancing the field of nuclear medicine and molecular imaging by supporting the practice and application of nuclear medicine. The first project focused on standardization of administered activities in pediatric nuclear medicine and resulted in 2 articles. For its second project the Nuclear Medicine Global Initiative chose to explore issues impacting on access and availability of radiopharmaceuticals around the world.

Halo Structure of the Neutron-Dripline Nucleus ^{19}B.

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220  MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.

Search for η^{'} Bound Nuclei in the ^{12}C(γ,p) Reaction with Simultaneous Detection of Decay Products.

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region.

Developments of real-time emittance monitors.

Under the upgrade program of an azimuthally varying field (AVF) cyclotron in progress at the Research Center for Nuclear Physics (RCNP), an emittance monitor is being developed to improve the beam injection efficiency from ion sources to the AVF cyclotron. In order to evaluate the quality of the beams extracted from ion sources quickly, we developed the Pepper-Pot type Emittance Monitor at the RCNP. After improving an analysis method for emittance estimation using LabVIEW, we achieved a measurement frequency of 4 Hz.

Targeted alpha therapy using astatine (At)-labeled phenylalanine: A preclinical study in glioma bearing mice.

Phenylalanine derivatives, which target tumors especially through L-type amino acid transporter-1 (LAT1), have elicited considerable attention. In this study, we evaluated the treatment effect of phenylalanine labeled with the alpha emitter astatine (At-PA) in tumor bearing mice. The C6 glioma, U-87MG, and GL261 cell lines were subjected to a cellular At-PA uptake analysis that included an evaluation of the uptake inhibition by the system L amino acid transporter inhibitor 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH).

Search for an Invisibly Decaying Z^{'} Boson at Belle II in e^{+}e^{-}→μ^{+}μ^{-}(e^{±}μ^{∓}) Plus Missing Energy Final States.

Theories beyond the standard model often predict the existence of an additional neutral boson, the Z^{'}. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z^{'} in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'} and of a lepton-flavor-violating Z^{'} in e^{+}e^{-}→e^{±}μ^{∓}Z^{'}. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes.

Nuclear Cardiology in Asia.

Nuclear cardiology for patients with ischemic heart disease and cardiac failure is expanding in Asia, although quite heterogeneously. In Asia, Israel showed the highest utilization with more than 1000 scans/100,000 inhabitants a year followed by Korea, Japan, UAE, Turkey, Australia (250-999 scans/100,000). Saudi Arabia, Kuwait, Jordan, Lebanon, Iran, and Pakistan practiced 60-99 scans/100,000.

Observation of the Radiative Decays of ϒ(1S) to χ_{c1}.

We report the first observation of the radiative decay of the ϒ(1S) into a charmonium state. The significance of the observed signal of ϒ(1S)→γχ_{c1} is 6.3 standard deviations including systematics.

Development of an MeV proton generator using a He ion source at the Research Center for Nuclear Physics.

For simple applications, such as the calibration of a charged particle detector, a multi-MeV proton generator may be preferable to cyclotrons or electrostatic accelerators such as Van de Graaff generator. Thus, a proton generating system, consisting of an 18 GHz superconducting (SC)-ECR ion source and a deuterated polyethylene target, was developed at the Research Center for Nuclear Physics at Osaka University. A He beam of 400 eμA was generated by the SC-ECR ion source with the acceleration voltage of 20 kV in an experiment that utilized the fusion reaction He + deuteron (D) → proton(P) + He.

Preclinical Evaluation of Radiation-Induced Toxicity in Targeted Alpha Therapy Using [At] NaAt in Mice: A Revisit.

We recently reported the dose-dependent therapeutic effect of At-NaAt in differentiated thyroid cancer xenograft models. In the present study, we evaluated the radiation-induced toxicity of At-NaAt using detailed hematological, biochemical, and histological analyses. Biodistribution of At-NaAt was measured in normal ICR mice (n = 12), absorbed doses in the major organs were calculated.

Swelling of Doubly Magic ^{48}Ca Core in Ca Isotopes beyond N=28.

Interaction cross sections for ^{42-51}Ca on a carbon target at 280  MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness.

Relationship between environmental radiation and radioactivity and childhood thyroid cancer found in Fukushima health management survey.

Environmental radioactive contamination caused by the Fukushima Dai-ichi Nuclear Power Plant accident has aroused great concern regarding a possible increase in the incidence of childhood thyroid cancer. The ultrasound examinations were conducted immediately after the accident as part of the Fukushima Health Management Survey (FHMS), which is divided into the preliminary baseline survey (PBLS) and the full-scale survey (FSS). Some of their outcomes are reported regularly and made available to the public.