Unconventional Crystal Structure of the High-Pressure Superconductor La_{3}Ni_{2}O_{7}.

The discovery of high-temperature superconductivity in La_{3}Ni_{2}O_{7} at pressures above 14 GPa has spurred extensive research efforts. Yet, fundamental aspects of the superconducting phase, including the possibility of a filamentary character, are currently subjects of controversial debates. Conversely, a crystal structure with NiO_{6} octahedral bilayers stacked along the c-axis direction was consistently posited in initial studies on La_{3}Ni_{2}O_{7}. Here, we reassess this structure in optical floating zone-grown La_{3}Ni_{2}O_{7} single crystals that show signs of filamentary superconductivity. Employing scanning transmission electron microscopy and single-crystal x-ray diffraction under high pressures, we observe multiple crystallographic phases in these crystals, with the majority phase exhibiting alternating monolayers and trilayers of NiO_{6} octahedra, signifying a profound deviation from the previously suggested bilayer structure. Using density functional theory, we disentangle the individual contributions of the monolayer and trilayer structural units to the electronic band structure of La_{3}Ni_{2}O_{7}, providing a firm basis for advanced theoretical modeling and future evaluations of the potential of the monolayer-trilayer structure for hosting superconductivity.

Associations among tooth loss, systemic inflammation and antibody titers to periodontal pathogens in Japanese patients with cardiovascular disease.

BACKGROUND AND OBJECTIVE: It is well known that there is a strong relationship between periodontitis and cardiovascular disease (CVD). Tooth loss reflects an end-stage condition of oral diseases, such as periodontitis. Infection with specific periodontal pathogens is known as a possible factor that influences development of CVD. The aim of this study was to assess the relationship between the number of residual teeth and systemic inflammatory conditions in patients with CVD. MATERIAL AND METHODS: We divided 364 patients with CVD into four groups, according to the number of residual teeth: (i) ≥20 teeth; (ii) 10-19 teeth; (iii) 1-9 teeth; and (iv) edentulous. We recorded medical history, blood data and periodontal conditions. Serum samples were obtained and their IgG titers against three major periodontal pathogens were measured. RESULTS: Smoking rate and the prevalence of diabetes mellitus were higher in edentulous patients and in subjects with a few teeth compared with patients with many teeth. The levels of C-reactive protein were higher in patients with 1-9 teeth than in those with 10-19 teeth and with ≥20 teeth. The level of Porphyromonas gingivalis IgG in the group with 10-19 teeth was statistically higher than that in the group with ≥20 teeth. The level of P. gingivalis IgG in the edentulous group tended to be lower than that in the other groups. CONCLUSION: The patients with 1-9 teeth had the highest level of C-reactive protein among the four groups, and the patients with 10-19 teeth had the highest level of IgG to periodontal bacteria. We conclude that the number of remaining teeth may be used to estimate the severity of systemic inflammation in patients with CVD.

Suppression of Trapped Energetic Ions Driven Resistive Interchange Modes with Electron Cyclotron Heating in a Helical Plasma.

The resistive interchange mode destabilized by the resonant interaction with the trapped energetic ions is fully suppressed when the injected power of electron cyclotron heating exceeds a certain threshold. It is shown for the first time that the complete stabilization of the energetic-particle-driven mode without relaxing the energetic particle (EP) pressure gradient is possible by reducing the radial width of the eigenmodes δ_{w}, especially when δ_{w} narrows to a small enough value relative to the finite orbit width of EP.

Abnormal asymmetries in subcortical brain volume in schizophrenia.

Subcortical structures, which include the basal ganglia and parts of the limbic system, have key roles in learning, motor control and emotion, but also contribute to higher-order executive functions. Prior studies have reported volumetric alterations in subcortical regions in schizophrenia. Reported results have sometimes been heterogeneous, and few large-scale investigations have been conducted. Moreover, few large-scale studies have assessed asymmetries of subcortical volumes in schizophrenia. Here, as a work completely independent of a study performed by the ENIGMA consortium, we conducted a large-scale multisite study of subcortical volumetric differences between patients with schizophrenia and controls. We also explored the laterality of subcortical regions to identify characteristic similarities and differences between them. T1-weighted images from 1680 healthy individuals and 884 patients with schizophrenia, obtained with 15 imaging protocols at 11 sites, were processed with FreeSurfer. Group differences were calculated for each protocol and meta-analyzed. Compared with controls, patients with schizophrenia demonstrated smaller bilateral hippocampus, amygdala, thalamus and accumbens volumes as well as intracranial volume, but larger bilateral caudate, putamen, pallidum and lateral ventricle volumes. We replicated the rank order of effect sizes for subcortical volumetric changes in schizophrenia reported by the ENIGMA consortium. Further, we revealed leftward asymmetry for thalamus, lateral ventricle, caudate and putamen volumes, and rightward asymmetry for amygdala and hippocampal volumes in both controls and patients with schizophrenia. Also, we demonstrated a schizophrenia-specific leftward asymmetry for pallidum volume. These findings suggest the possibility of aberrant laterality in neural pathways and connectivity patterns related to the pallidum in schizophrenia.

Resistive interchange modes destabilized by helically trapped energetic ions in a helical plasma.

A new bursting m=1/n=1 instability (m,n: poloidal and toroidal mode numbers) with rapid frequency chirping down has been observed for the first time in a helical plasma with intense perpendicular neutral beam injection. This is destabilized in the plasma peripheral region by resonant interaction between helically trapped energetic ions and the resistive interchange mode. A large radial electric field is induced near the edge due to enhanced radial transport of the trapped energetic ions by the mode, and leads to clear change in toroidal plasma flow, suppression of microturbulence, and triggering an improvement of bulk plasma confinement.

Investigation of dyeing behavior of oxidative dye in fine structures of the human hair cuticle by nanoscale secondary ion mass spectrometry.

BACKGROUND/PURPOSE: In oxidative coloring, the hair cuticle layers are not only the penetration pathway for active ingredients but also one of the most important dyeing regions. The dyeing mechanism of oxidative dyes in fine structures of the cuticle remains unclear. To investigate the dyeing behavior of oxidative dyes in fine structures of the cuticle, hair cross-sections were analyzed by nanoscale secondary ion mass spectrometry (NanoSIMS). METHODS: The preparation method of hair cross-section for NanoSIMS measurement was improved. Improved hair cross-sections were analyzed using NanoSIMS. RESULTS: The cuticle layer thickness of the hair cross-section could be widened. It was confirmed that (12) C(-) ions were more strongly detected from endocuticle than from other fine structures of cuticle. The NanoSIMS (12) C(-) image and hue saturation intensity (HSI) D(-) /(1) H(-) ratio image of the hair, dyed with deuterium-labeled oxidative dye, indicated that the endocuticle had a higher D(-) /(1) H(-) ratio than the other fine structures of the cuticle. It was substantiated that more colored chromophores were fixated in the endocuticle than in other fine structures of the cuticle. CONCLUSION: The dyeing behavior of oxidative dyes in fine structures of hair cuticle was substantiated by NanoSIMS analysis using the improved hair cross-section preparation method.

The initial measurement of a compact D-T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for fusion plasma diagnostic.

For developing and characterizing a novel compact D-T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for plasma diagnostics toward future D-T fusion reactors, the initial measurement was performed using the accelerator-based D-T neutron sources OKTAVIAN at Osaka University. This neutron spectrometer was designed for the detection of 3-17 MeV neutrons and operated in the proton recoil telescope configuration by installing a polyethylene converter in front of the diamond stack. The measured neutron energy spectra were obtained by summing the energy of the recoil protons deposited in the diamond stack after the coincidence of the recoil protons identified by the time coincidence analysis. The neutron energy peaks measured by the compact D-T neutron spectrometer were almost in agreement with those obtained by the Monte Carlo N-Particle transport (MCNP) simulation. The energy resolution of the compact D-T neutron spectrometer was emulated to be about 4%-5% in D-T neutron measurement. In future work, the design of the compact D-T neutron spectrometer would be optimized to measure the fusion neutron for plasma diagnostics.

Design and initial results of the imaging neutral particle analyzer in large helical device.

A novel Imaging Neutral Particle Analyzer (INPA) was newly installed in early 2024 to enhance the understanding of fast ion confinement on Large Helical Devices (LHDs). This diagnostic system, based on a magnetic spectrometer using a scintillator, provides energy-resolved radial profiles of confined fast ions by measuring charge-exchanged fast neutrals escaping from the plasma. The system utilizes a 100 nm thick carbon foil to ionize the fast neutrals, subsequently deflecting the ions toward a scintillator via the existing local magnetic field. The fast ion energy and sightline determine the position of the scintillation, while the light intensity depends on the flux of the fast ions. The INPA features two apertures, facilitating effective measurements in both clockwise and counterclockwise magnetic field directions in the LHD. This INPA was designed as a passive measurement system that measures fast ions charge exchange with background neutrals, focusing on perpendicular beam ions from 5 to 100 keV with an energy resolution of about 5.75 keV. This paper describes the details of the design, installation, and the initial results of the INPA on the LHD. This work will contribute significantly to a deeper understanding of fast ion transport due to magnetohydrodynamic instabilities.

Robustness of basal-plane antiferromagnetic order and the J(eff)=1/2 state in single-layer iridate spin-orbit Mott insulators.

The magnetic structure and electronic ground state of the layered perovskite Ba(2)IrO(4) have been investigated using x-ray resonant magnetic scattering. Our results are compared with those for Sr(2)IrO(4), for which we provide supplementary data on its magnetic structure. We find that the dominant, long-range antiferromagnetic order is remarkably similar in the two compounds and that the electronic ground state in Ba(2)IrO(4), deduced from an investigation of the x-ray resonant magnetic scattering L(3)/L(2) intensity ratio, is consistent with a J(eff)=1/2 description. The robustness of these two key electronic properties to the considerable structural differences between the Ba and Sr analogues is discussed in terms of the enhanced role of the spin-orbit interaction in 5d transition metal oxides.

Fast-sampling fast-ion D-alpha measurement using multi-anode photomultiplier tube in large helical device.

A fast-sampling fast-ion D-alpha (F-FIDA) measurement has been developed in the large helical device in order to investigate fast ion dynamics associated with helically trapped fast-ion-driven Magnetohydrodynamic (MHD) bursts. F-FIDA consists of a multi-anode photomultiplier tube (PMT) and achieves a sampling rate of 10 kHz. During the deuterium experiment campaign in 2022, F-FIDA measured the spectrum of perpendicular fast ions, using perpendicular lines of sight. We compared F-FIDA with conventional FIDA, using an electron multiplying charge coupled device, and confirmed that the time-averaged images were generally consistent between the two. The statistical properties of the temporal evolution associated with MHD bursts were analyzed using a conditional sampling technique. The results showed that the PMT signal varied in different spatial and wavelength channels. Although the signal-to-noise ratio was poor and there was room for improvement, it could provide useful information for studies on the phase-space dynamics of fast ions.

Optimization of a fast deuterium diagnostic method based on visible energetic 3He spectroscopy for high electron density plasmas.

Fast ions play a crucial role in plasma heating, and their behavior in the plasma must be accurately understood. A diagnostics method based on charge exchange emission from the n = 4 - 3 transition (λ0 = 468.6 nm) of energetic 3He produced by the deuteron-deuteron reaction has been proposed as a for fast deuterons with energies in the order of MeV. The proposed method has the following advantages: No beam emission interferes with the spectra, the direction of the measuring line of sight, and the injection angle of the diagnostic beam can be freely determined. In previous studies, due to competing bremsstrahlung, it was expected that the proposed method will not be practical in the case of high electron density operation. This paper makes the proposed method available for measurement even at high electron densities by optimizing the measurement line of sight direction and the diagnostic beam incidence angle. This allows an electron density five times larger than the range of applications shown in previous studies. This result will contribute to measure of DT alpha in ITER.

First measurements of p11B fusion in a magnetically confined plasma.

Proton-boron (p11B) fusion is an attractive potential energy source but technically challenging to implement. Developing techniques to realize its potential requires first developing the experimental capability to produce p11B fusion in the magnetically-confined, thermonuclear plasma environment. Here we report clear experimental measurements supported by simulation of p11B fusion with high-energy neutral beams and boron powder injection in a high-temperature fusion plasma (the Large Helical Device) that have resulted in diagnostically significant levels of alpha particle emission. The injection of boron powder into the plasma edge results in boron accumulation in the core. Three 2 MW, 160 kV hydrogen neutral beam injectors create a large population of well-confined, high -energy protons to react with the boron plasma. The fusion products, MeV alpha particles, are measured with a custom designed particle detector which gives a fusion rate in very good relative agreement with calculations of the global rate. This is the first such realization of p11B fusion in a magnetically confined plasma.

Clarithromycin suppresses the periodontal bacteria-accelerated abdominal aortic aneurysms in mice.

BACKGROUND AND OBJECTIVE: Although clarithromycin (CAM) has many biological functions, including regulation of MMPs, little is known about its effect on abdominal aortic aneurysms. Periodontopathic bacteria have been reported to be associated with several kinds of circulatory diseases. The purpose of this study was therefore to clarify the effect of CAM on periodontopathic bacteria-accelerated abdominal aortic aneurysms. MATERIAL AND METHODS: Abdominal aortic aneurysm was produced in mice by the peri-aortic application of 0.25 m CaCl(2). The mice were inoculated once per week with live Porphyromonas gingivalis, which is one of the major periodontopathic bacteria. Test mice (n=8) were given a daily oral dose of CAM, while control mice (n=13) were not. RESULTS: Four weeks after the operation, the P. gingivalis-injected and CAM-treated mice showed a significant decrease in the aortic diameter in comparison with the mice only injected with P. gingivalis. Histopathologically, the samples obtained from the P. gingivalis-injected and CAM-treated mice showed less elastic degradation. Moreover, the plasma MMP-2 concentration of the CAM-treated mice decreased significantly. CONCLUSION: These findings suggest that CAM administration is useful to suppress periodontal bacteria-accelerated abdominal aortic aneurysms via MMP regulation.

Generalized bond order parameters to characterize transient crystals.

Higher order parameters in the hard disk fluid are computed to investigate the number, the lifetime, and size of transient crystal nuclei in the pre-freezing phase. The methodology introduces further neighbor shells bond orientational order parameters and coarse-grains the correlation functions needed for the evaluation of the stress autocorrelation function for the viscosity. We successfully reproduce results by the previous collision method for the pair orientational correlation function, but some two orders of magnitude faster. This speed-up allows calculating the time dependent four body orientational correlation between two different pairs of particles as a function of their separation, needed to characterize the size of the transient crystals. The result is that the slow decay of the stress autocorrelation function near freezing is due to a large number of rather small crystal nuclei lasting long enough to lead to the molasses tail.

Initial operation of perpendicular line-of-sight compact neutron emission spectrometer in the large helical device.

The perpendicular line-of-sight compact neutron emission spectrometer (perpendicular CNES) was newly installed to understand the helically trapped fast-ion behavior through deuterium-deuterium (D-D) neutron energy spectrum measurement in the Large Helical Device (LHD). The energy calibration of the EJ-301 liquid scintillation detector system for perpendicular CNES was performed on an accelerator-based D-D neutron source. We installed two EJ-301 liquid scintillation detectors, which view the LHD plasma vertically from the lower side through the multichannel collimator. The D-D neutron energy spectrum was measured in a deuterium perpendicular-neutral-beam-heated deuterium plasma. By the derivative unfolding technique, it was found that the D-D neutron energy spectrum had a double-humped shape with peaks at ∼2.33 and ∼2.65 MeV. D-D neutron energy spectrum was calculated based on the fast ion distribution function using guiding center orbit-following models considering the detector's energy resolution. The calculated peak energies in the D-D neutron energy spectrum almost match the experiment. In addition, a feasibility study toward the measurement of the energy distribution of ion-cyclotron-range-of-frequency-wave-accelerated beam ions was performed.

A gamma ray spectrometer with Compton suppression on the HL-2A tokamak.

A new broad-energy, high-resolution gamma ray spectrometer (GRS) with Compton suppression function has been developed recently in the HL-2A tokamak to obtain the gamma ray information in the energy range of 0.1-10 MeV. This is the first time to develop an anti-Compton GRS for a magnetic confinement fusion device. The anticoincidence detector consists of a large-volume high purity germanium (HPGe) crystal (Φ63 × 63 mm2) as the primary detector and eight trapezoidal bismuth germinate (BGO) scintillators (trapezoid crystal with 30 mm thickness) as the secondary detector. The anti-coincidence data processing is implemented by a digital-based data acquisition system with fast digitization and software signal processing technology. Using radioisotope gamma ray sources and Monte Carlo N-Particle code, the energy and efficiency of the spectrometer have been calibrated and quantitatively tested. The Compton continuum suppression factor reaches 4.2, and the energy resolution (Full Width at Half Maximum) of the 1.332 MeV full energy peak for 60Co is 2.1 keV. Measurements of gamma ray spectra with Compton suppression using the spectrometer have been successfully performed during HL-2A discharges with different conditions. The performance of the spectrometer and the first experimental results are presented in this paper.

Peierls mechanism of the metal-insulator transition in ferromagnetic hollandite K2Cr8O16.

Synchrotron x-ray diffraction experiment shows that the metal-insulator transition occurring in a ferromagnetic state of a hollandite K(2)Cr(8)O(16) is accompanied by a structural distortion from the tetragonal I4/m to monoclinic P112(1)/a phase with a √2×√2×1 supercell. Detailed electronic structure calculations demonstrate that the metal-insulator transition is caused by a Peierls instability in the quasi-one-dimensional column structure made of four coupled Cr-O chains running in the c direction, leading to the formation of tetramers of Cr ions below the transition temperature. This provides a rare example of the Peierls transition of fully spin-polarized electron systems.

Dimerization and charge order in hollandite K2V8O16.

The metal-insulator transition occurring in hollandite K2V8O16 has been studied by means of neutron and x-ray diffraction as well as by thermodynamic and electron-spin resonance measurements. The complete analysis of the crystal structure in the distorted phase allows us to identify dimerization as the main distortion element in insulating K2V8O16. At low-temperature, half of the V chains are dimerized perfectly explaining the suppression of magnetic susceptibility due to the formation of spin singlets. The dimerization is accompanied by the segregation of charges into chains.

Porphyromonas gingivalis promotes murine abdominal aortic aneurysms via matrix metalloproteinase-2 induction.

BACKGROUND AND OBJECTIVE: Abdominal aortic aneurysm (AAA) is a common and lethal disorder, and MMPs are highly expressed in AAA lesions. Large numbers of periodontopathic bacteria have been reported to be present in specimens obtained from the aortic walls of patients with an AAA. The purpose of this study was to analyze the influence of periodontopathic bacteria on AAA dilatation. MATERIAL AND METHODS: AAAs were produced in mice by the periaortic application of 0.25 M CaCl(2), and NaCl was used as a control. The mice were inoculated once weekly with live Porphyromonas gingivalis, live Aggregatibacter actinomycetemcomitans or vehicle. RESULTS: Four weeks after the periaortic application of either CaCl(2) or NaCl, a significant increase was observed in the aortic diameter of P. gingivalis-challenged mice compared with the vehicle control mice (p < 0.05), whereas there was no statistically significant increase in the aortic diameter of the A. actinomycetemcomitans-challenged mice. Immunohistochemical analysis found significantly higher numbers of CD8-positive and MOMA2-positive cells and significantly higher levels of MMP-2 in the aneurysmal samples of P. gingivalis-challenged mice compared with control mice. Live P. gingivalis promoted a significant proliferation of splenocytes in comparison with P. gingivalis-lipopolysaccharide and live A. actinomycetemcomitans (p < 0.05). CONCLUSION: These findings demonstrate that challenge with P. gingivalis, but not with A. actinomycetemcomitans, can accelerate, or even initiate, the progression of experimental AAA through the increased expression of MMPs.

Prevention of graft coronary arteriosclerosis by antisense cdk2 kinase oligonucleotide.

Graft coronary arteriosclerosis, which limits the long-term survival of allograft recipients, is characterized by diffuse intimal thickening composed of proliferative smooth muscle cells. We observed that messenger RNA of the cell cycle regulatory enzyme cyclin-dependent kinase (cdk) 2 kinase, which mediates smooth muscle cell proliferation, was elevated in the thickened intima of coronary arteries of murine heterotopic cardiac allografts. We studied the effects of antisense phosphorothioate oligodeoxynucleotide (ODN) against this enzyme using gene transfer mediated by a hemagglutinating virus of Japan (HVJ)-liposome complex intraluminally delivered to inhibit the intimal hyperplasia. At 30 days after transplantation, antisense cdk2 kinase ODN treatment had dramatically inhibited neointimal formation in the allografts. Expression of vascular cell adhesion molecule-1 was also suppressed by antisense cdk2 kinase. However, these effects were not observed in the sense or scrambled ODN-treated allografts. Thus, an intraluminal administration of antisense ODN directed to a specific cell cycle regulatory gene can inhibit neointimal formation after cardiac transplantation.