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The fragmentation reactions of neutron-rich unstable nuclei 81Ga and 82Ge at 250 MeV/nucleon have been studied in order to search the optimal mean for the production of very neutron-rich nuclei in the vicinity of 78Ni. The newly measured cross sections were compared with various calculations, showing a good agreement with EPAX3.01. The present work provides experimental insights into the two-step scheme—fragmentation following fission—as a method to produce very neutron-rich nuclei through a combination of ISOL and fragmentation of post-accelerated beams of unstable nuclei. Our results enable an evaluation of the potential of the two-step scheme in the production of very neutron-rich nuclei for the 78Ni region. The two-step scheme using fragmentation of a post-accelerated 81Ga beam could be an option to produce neutron-rich nuclei around 78Ni when the 81Ga beam intensity reaches 1.0×108 pps, compared to the one-step scheme with fission of 238U.

In this work we investigate the two-neutron decay of 13Li and of the excited states of 11Li populated via one-proton removal from 14Be and 12Be, respectively. A phenomenological model is used to describe the decay of 11Li and 13Li. While the first one displays important sequential components, the second one appears dominated by the direct two-neutron decay. A microscopic three-body model is used to extract information on the spatial configuration of the emitted neutrons before the decay and shows that the average distance between the neutrons increases going from 11Li to 13Li.

The calcium isotopes are an ideal system to investigate the evolution of shell structure and magic numbers. Although the properties of surface nucleons in calcium have been well studied, probing the structure of deeply bound nucleons remains a challenge. Here, we report on the first measurement of unbound states in 53Ca and 55Ca, populated from 54,56Ca(p,pn) reactions at a beam energy of around 216 MeV/nucleon at the RIKEN Radioactive Isotopes Beam Factory. The resonance properties, partial cross sections, and momentum distributions of these unbound states were analyzed. Orbital angular momentum l assignments were extracted from momentum distributions based on calculations using the distorted wave impulse approximation (DWIA) reaction model. The resonances at excitation energies of 5516(41)keV in 53Ca and 6000(250)keV in 55Ca indicate a significant l =3 component, providing the first experimental evidence for the ν0f7/2 single-particle strength of unbound hole states in the neutron-rich Ca isotopes. The observed excitation energies and cross-sections point towards extremely localized and well separated strength distributions, with some fragmentation for the ν0f7/2 orbital in 55Ca. These results are in good agreement with predictions from shell-model calculations using the effective GXPF1Bs interaction and ab initio calculations and diverge markedly from the experimental distributions in the nickel isotones at Z=28.

Properties of the nuclear equation of state (EoS) can be probed by measuring the dynamical properties of nucleus-nucleus collisions. In this study, we present the directed flow (v1), elliptic flow (v2) and stopping (VarXZ) measured in fixed target Sn + Sn collisions at Image 1 with the SπRIT Time Projection Chamber. We perform Bayesian analyses in which EoS parameters are varied simultaneously within the Improved Quantum Molecular Dynamics-Skyrme (ImQMD-Sky) transport code to obtain a multivariate correlated constraint. The varied parameters include symmetry energy, S0, and slope of the symmetry energy, L, at saturation density, isoscalar effective mass, ms⁎/mN, isovector effective mass, mv⁎/mN and the in-medium cross-section enhancement factor η. We find that the flow and VarXZ observables are sensitive to the splitting of proton and neutron effective masses and the in-medium cross-section. Comparisons of ImQMD-Sky predictions to the SπRIT data suggest a narrow range of preferred values for ms⁎/mN, mv⁎/mN and η.

γ emission probabilities from unbound states in 78,80Se, populated by a neutron-transfer reaction (d,p) on 77,79Se nuclei in inverse kinematics, were measured by directly detecting reaction residues. Assuming the spin distribution at the respective excitation energy of the unbound state, the cross-sections of the 79Se(n,γ)80Se reaction were evaluated using the γ emission probabilities. The surrogate-ratio method with the experimental γ emission probabilities of 78,80Se was also employed to deduce the cross-sections of 79Se(n,γ) reaction by incorporating the theoretical evaluations of the neutron-capture reaction on the isomeric state in 77Se. Our two cross-sections are in good agreement with existing nuclear data compilations for the neutron-capture reaction on 79Se. The presented method contributes to the body of existing knowledge by providing approaches for determining the neutron capture cross-sections of radioactive nuclei at various neutron energies.

The nuclear structure of 66Se, nucleus beyond the N=Z line on the proton-rich side of the valley of stability, was investigated by the neutron knock-out reaction 67Se(12C,X)66Se using a 12C target. The analysis of the singles spectrum of the γ-rays emitted during the de-excitation of the populated low-lying excited states revealed two previously detected (927(4) keV, 1460(32) keV) and three new (744(6) keV, 1210(17) keV, 1661(23) keV) transitions. The 744-keV, the 1210-keV, and the 1460-keV transitions were found to be in coincidence with the one at 927 keV. The spectrum coincident with the 927-keV transition showed a further possible transition at 299(35) keV, which was obscured by significant atomic background in the singles spectrum. This transition might correspond to a peak previously reported at 273(5) keV that could not be assigned to 66Se unambiguously. Based on a comparison of the experimental data to theoretical calculations, four new excited states are proposed which suggest that 66Se exhibits shape coexistence.

Gamma decays were observed in 56Ca and 58Ca following quasi-free one-proton knockout reactions from 57,59Sc beams at ≈200 MeV/nucleon. For 56Ca, a γ ray transition was measured to be 1456(12) keV, while for 58Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic 60Ca and potentially drives the dripline of Ca isotopes to 70Ca or even beyond.

Detailed γ-ray spectroscopy of the exotic neon isotope 28Ne has been performed for the first time using the one-neutron removal reaction from 29Ne on a liquid hydrogen target at 240 MeV/nucleon. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for 28Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N=20 and N=28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

The dineutron correlation is systematically studied in three different Borromean nuclei near the neutron dripline, 11Li, 14Be and 17B, via the (p,pn) knockout reaction measured at the RIBF facility in RIKEN. For the three nuclei, the correlation angle between the valence neutrons is found to be largest in the same range of intrinsic momenta, which can be associated to the nuclear surface. This result reinforces the prediction that the formation of the dineutron is universal in environments with low neutron density, such as the surface of neutron-rich Borromean nuclei.

Unbound states in C17 were investigated via one-neutron removal from a C18 beam at an energy of 245 MeV/nucleon on a carbon target. The energy spectrum of C17, above the single-neutron decay threshold, was reconstructed using invariant mass spectroscopy from the measured momenta of the C16 fragment and neutron, and was found to exhibit resonances at Er=0.52(2), 0.77(2), 1.36(1), 1.91(1), 2.22(3) and 3.20(1) MeV. The resonance at Er=0.77(2) MeV [Ex=1.51(3) MeV] was provisionally assigned as the second 5/2+ state. The two resonances at Er=1.91(1) and 3.20(1) MeV [Ex=2.65(2) and 3.94(2) MeV] were identified, through comparison of the energies, cross sections and momentum distributions with shell-model and eikonal reaction calculations, as p-shell hole states with spin-parities 1/21− and 3/21−, respectively. A detailed comparison was made with the results obtained using a range of shell-model interactions. The YSOX shell-model Hamiltonian, the cross-shell part of which is based on the monopole-based universal interaction, was found to provide a very good description of the present results and those for the neighbouring odd-A carbon isotopes – in particular for the negative parity cross-shell states.

States in the N=35 and 37 isotopes 55,57Ca have been populated by direct proton-induced nucleon removal reactions from 56,58Sc and 56Ca beams at the RIBF. In addition, the (p,2p) quasi-free single-proton removal reaction from 56Ca was studied. Excited states in 55K, 55Ca, and 57Ca were established for the first time via in-beam γ-ray spectroscopy. Results for the proton and neutron removal reactions from 56Ca to states in 55K and 55Ca for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in 57Ca suggests a transition in the calcium isotopic chain from single-particle dominated states at N=35 to collective excitations at N=37.

Background: The single-nucleotide polymorphism rs6507583 at the promoter of SET-binding protein 1 (SETBP1) was implicated in estrogen receptor (ER)-positive breast carcinogenesis. Here, we evaluated the clinical and biological relevance of SETBP1 expression in ER-positive breast cancer (BC)., Methods: The associations between SETBP1 expression and clinical outcomes in BC patients were analyzed in independent cohorts. The localizations of SETBP1 expression in BC tissues were observed by immunohistochemical staining. Pathway analyses were conducted using TCGA dataset. In vitro proliferation assay, protein phosphatase 2A (PP2A) activity assay, and gene expression analysis were performed in SETBP1-knockdown ER-positive BC cells. We investigated the factors influencing SETBP1 mRNA expression using TCGA dataset. rs6507583 presence and SETBP1 mRNA expression in 11 mammary cell lines and 56 BC tissue samples were examined by target sequencing and RT-qPCR, respectively., Results: SETBP1 was downregulated in BC cells compared with normal ductal epithelial cells. Low SETBP1 mRNA expression was an independent prognostic factor for poor recurrence-free survival. Pathway analyses revealed an inverse relationship between decreased SETBP1 expression and the expression of E2F, MYC, and G2M checkpoint target genes in BC tissues. SETBP1 knockdown promoted proliferation, inhibition of PP2A activity, and phosphorylation of MAPK in ER-positive BC. Low SETBP1 expression was influenced by high SETBP1 promoter methylation and DNA copy number SETBP1 deletion. SETBP1 expression with rs6507583 was lower than without rs6507583 in BC., Conclusions: We demonstrated that low SETBP1 expression could be a poor prognostic biomarker that promotes ER-positive BC proliferation, possibly via phosphorylation of MAPK., Competing Interests: Declarations. Conflict of interest: The authors confirm that they have no conflicts of interest with respect to the work described in this manuscript., (© 2025. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Background/aim: MicroRNAs (miRNAs) have been highlighted as non-invasive clinical biomarkers in liquid biopsy. This study aimed to investigate the clinical significance of circulating tumor suppressors, precursor-miR-488 (pre-miR-488) and miR-488-5p, in the blood of patients with gastric cancer (GC)., Materials and Methods: The expression levels of pre-miR-488 and miR-488-5p in tumor tissues and blood were measured using RT-qPCR, and the clinicopathological and prognostic significance of their expression was assessed in patients with GC. Next, pathway analysis of miR-488-5p expression in GC tissues was performed by gene set enrichment analysis (GSEA) using the TCGA dataset. Finally, pre-miR-488 in exosomes from the plasma of GC patients was analyzed using RT-qPCR., Results: Both pre-miR-488 and miR-488-5p were down-regulated in tumor tissues, whereas their expression in the blood was significantly higher in patients with GC than in healthy controls. Low expression of pre-miR-488 or miR-488-5p in the blood was associated with poor prognosis in patients with GC. Furthermore, low pre-miR-488 expression in the blood was an independent poor prognostic factor for overall survival. miR-488-5p expression tended to be negatively correlated with the expression of gene sets involved in epithelial-mesenchymal transition and hypoxia. pre-miR-488 was detected in exosomes isolated from the plasma of patients with GC., Conclusion: Circulating pre-miR-488 and miR-488-5p expression in the blood may serve as novel prognostic biomarkers for patients with GC, predicting clinical outcomes and guiding therapeutic strategies., (Copyright © 2025 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The neutron-rich unbound fluorine isotope ^{30}F_{21} has been observed for the first time by measuring its neutron decay at the SAMURAI spectrometer (RIBF, RIKEN) in the quasifree proton knockout reaction of ^{31}Ne nuclei at 235  MeV/nucleon. The mass and thus one-neutron-separation energy of ^{30}F has been determined to be S_{n}=-472±58(stat)±33(sys)  keV from the measurement of its invariant-mass spectrum. The absence of a sharp drop in S_{n}(^{30}F) shows that the "magic" N=20 shell gap is not restored close to ^{28}O, which is in agreement with our shell-model calculations that predict a near degeneracy between the neutron d and fp orbitals, with the 1p_{3/2} and 1p_{1/2} orbitals becoming more bound than the 0f_{7/2} one. This degeneracy and reordering of orbitals has two potential consequences: ^{28}O behaves like a strongly superfluid nucleus with neutron pairs scattering across shells, and both ^{29,31}F appear to be good two-neutron halo-nucleus candidates.

Elevated levels of miR-155 in solid and liquid malignancies correlate with aggressiveness of the disease. In this manuscript, we show that miR-155 targets transcripts encoding IcosL, the ligand for Inducible T-cell costimulator (Icos), thus impairing the ability of T cells to recognize and eliminate malignant cells. We specifically found that overexpression of miR-155 in B cells of Eµ- miR-155 mice causes loss of IcosL expression as they progress toward malignancy. Similarly, in mice where miR-155 expression is controlled by a Cre-Tet-OFF system, miR-155 induction led to malignant infiltrates lacking IcosL expression. Conversely, turning miR-155 OFF led to tumor regression and emergence of infiltrates composed of IcosL-positive B cells and Icos-positive T cells forming immunological synapses. Therefore, we next engineered malignant cells to express IcosL, in order to determine whether IcosL expression would increase tumor infiltration by cytotoxic T cells and reduce tumor progression. Indeed, overexpressing an IcosL -encoding cDNA in MC38 murine colon cancer cells before injection into syngeneic C57BL6 mice reduced tumor size and increased intratumor CD8+ T cell infiltration, that formed synapses with IcosL-expressing MC38 cells. Our results underscore the fact that by targeting IcosL transcripts, miR-155 impairs the infiltration of tumors by cytotoxic T cells, as well as the importance of IcosL on enhancing the immune response against malignant cells. These findings should lead to the development of more effective anticancer treatments based on maintaining, increasing, or restoring IcosL expression by malignant cells, along with impairing miR-155 activity., Competing Interests: Competing interests statement:The authors declare no competing interest.

The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for the first time, with energies of 0.84(3) and 2.15(5) MeV above the two-neutron decay threshold and widths of 0.32(8) and 0.95(15) MeV, respectively. These were assigned to be the ground (J^{π}=0^{+}) and first excited (2^{+}) state, with E_{x}=1.31(6)  MeV. The mass excess of ^{16}Be was thus deduced to be 56.93(13) MeV, some 0.5 MeV more bound than the only previous measurement. Both states were observed to decay by direct two-neutron emission. Calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component, while the 2^{+} level presents a far more diffuse neutron-neutron distribution.

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

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. The remarkable agreement between calculated and measured cross sections in both shape and magnitude validates the molecular structure description of the ^{10}Be ground-state, configured as an α-α core with two valence neutrons occupying π-type molecular orbitals.

Hot springs have long been used for medical purposes throughout the world. Recently, the positive effects of hot spa-bathing on circulatory diseases have been reported, while there are few reports on the mental effects of hot spa-bathing. Therefore, the purpose of this study was to clarify the relationship between hot spa-bathing habits and mental health throughout Japan. We conducted a nationwide online survey, including questions on bathing behavior, subjective satisfaction, lifestyle, and illness. The results showed a significant positive correlation between hot spa-bathing habits and multiple subjective satisfaction levels regarding mental health effects. The factor analysis results indicated that hot spa-bathing habits tended to be associated with good mental health, high health consciousness, and disease. Our study revealed that subjective satisfaction was higher among individuals with hot spa-bathing habits, suggesting that the hot spring spa-bathing habit may have a positive influence on mental health., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

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 -21  s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28 O and 27 O through their decay into 24 O and four and three neutrons, respectively. The 28 O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers 1,2 , it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27 O and 28 O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28 O from a 29 F beam is consistent with it not exhibiting a closed N = 20 shell structure., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

The new isotope ^{39}Na, the most neutron-rich sodium nucleus observed so far, was discovered at the RIKEN Nishina Center Radioactive Isotope Beam Factory using the projectile fragmentation of an intense ^{48}Ca beam at 345  MeV/nucleon on a beryllium target. Projectile fragments were separated and identified in flight with the large-acceptance two-stage separator BigRIPS. Nine ^{39}Na events have been unambiguously observed in this work and clearly establish the particle stability of ^{39}Na. Furthermore, the lack of observation of ^{35,36}Ne isotopes in this experiment significantly improves the overall confidence that ^{34}Ne is the neutron dripline nucleus of neon. These results provide new key information to understand nuclear binding and nuclear structure under extremely neutron-rich conditions. The newly established stability of ^{39}Na has a significant impact on nuclear models and theories predicting the neutron dripline and also provides a key to understanding the nuclear shell property of ^{39}Na at the neutron number N=28, which is normally a magic number.

Aim: Gastric mucosal changes associated with chronic gastritis are known to be precancerous lesions of gastric cancer. We aimed to identify individuals with a high risk of gastric cancer by detection of microRNAs (miRNA) in the blood as biomarkers., Methods: Of 1206 individuals screened, 144 who were positive for Helicobacter pylori ( H. pylori ) by the serum antibody test and who underwent endoscopy were the subjects of this study. For the gross assessment of mucosal inflammation, we applied the Kimura-Takemoto classification, in which normal mucosa was defined as grade 0, and atrophy was categorized as grade 1 (C-1 and C-2), grade 2 (C-3 and O-1), and grade 3 (O-2 and O-3). Serum samples were divided into two phases and used for miRNA microarray profiling. We compared the expression of miRNAs in grade 3 mucosa and other grades. Expression in gastric cancer was confirmed with TCGA data., Results: miR-196b-3p was significantly upregulated, and miR-92a-2-5p was downregulated ( P  < .05 and q  < 0.2). TCGA data showed a high expression of miR-196b-3p in gastric cancer cases ( P  < .001). Comparing grade 3 and the others, the area under the receiver operating characteristic curve using the detected miRNAs was as high as about 0.7. Furthermore, the combination of miRNAs resulted in higher accuracy. In terms of the significance of the combinatory mRNAs, the combination of three miRNAs ( miR-196b-3p , miR-92a-2-5p , and miR-6791-3p ) revealed high sensitivity and specificity, with the area under the curve exceeding 0.8., Conclusion: The identified combinatory miRNAs may represent promising biomarkers of precancerous lesions in gastric cancer., (© 2022 The Authors. Annals of Gastroenterological Surgery published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Gastroenterology.)

A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. To our knowledge, only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades 1 , with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far 2-4 , leaving the tetraneutron an elusive nuclear system for six decades. Here we report on the observation of a resonance-like structure near threshold in the four-neutron system that is consistent with a quasi-bound tetraneutron state existing for a very short time. The measured energy and width of this state provide a key benchmark for our understanding of the nuclear force. The use of an experimental approach based on a knockout reaction at large momentum transfer with a radioactive high-energy 8 He beam was key., (© 2022. The Author(s).)

Background: The mainstream first-line chemotherapy for advanced/recurrent gastric cancer (ARGC) is combination therapy including platinum-based agents. With the progressive aging of the society, the incidence of gastric cancer in elderly patients is increasing. However, elderly patients cannot tolerate these agents because of renal dysfunction or low quality of life. The KSCC1701 study explored the efficacy and safety of S-1 + ramucirumab in elderly patients with ARGC., Patients and Methods: Chemotherapy-naive patients aged ≥70 years with ARGC were eligible. Patients received S-1 (40-60 mg twice daily for 4 weeks in 6-week cycles) and ramucirumab (8 mg/kg every 2 weeks) until disease progression. The primary end-point was the 1-year overall survival (OS) rate. The anticipated lower threshold of 1-year survival was set at 40% in light of previous S-1-based regimens. The secondary end-points included progression-free survival (PFS), OS, the overall response rate (ORR) and safety., Results: Between September 2017 and November 2019, 48 patients (34 men and 14 women) were enrolled in this study. The median patient age was 77.5 years, and all patients had a performance status of 0 (n = 20) or 1 (n = 28). The 1-year OS rate was 65.2%, which met the primary end-point. The median survival time and median PFS were 16.4 and 5.8 months, respectively. The ORR was 41.9%. The most frequent grade 3/4 (≥15%) adverse events were neutropenia, anorexia and anaemia., Conclusion: Considering these findings, S-1 + ramucirumab appears to be an excellent treatment option for elderly patients with ARGC. (250 words). This trial has been registered with the Japan Registry of Clinical Trials Registry under the number jRCTs071180066., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)