The effect of high‐pressure oxygen (HPO) annealing on the electrical, magnetic, and magnetoelectric (ME) properties of room‐temperature multiferroic BaSrCo2Fe11AlO22 ceramics was investigated. The ...electrical resistivity of the ceramics was found to strongly depend on the partial oxygen pressure during annealing at 1040°C. Samples annealed under ~10 atm of oxygen exhibited a resistivity of up to 1.6 × 109 Ω·cm at room temperature, more than two orders of magnitude higher than that of samples without oxygen annealing. Thermally stimulated current and complex impedance measurements suggested that the enhancement of the resistivity by the HPO annealing originated from a decrease in the amount of defects related to oxygen vacancies and an increase in the resistance of grains and interfaces. HPO annealing also affects the magnetic‐field response of spiral magnetic ordering, which is ascribed to the ME properties. Furthermore, samples subjected to HPO annealing exhibited a lower contribution of the space charges trapped at the grain boundaries and/or defects to the magnitude of the measured magnetoelectrically induced electric polarization P. The present results indicate that HPO annealing is an effective method to evaluate authentic ME effects in multiferroic BaSrCo2Fe11AlO22 ceramics.
In this study, we designed and synthesized an implantable anti-CD25 antibody-immobilized polyethylene (CD25-PE) mesh to suppress tumor growth by removing regulatory T cells (Tregs). The PE mesh was ...graft-polymerized with poly(acrylic acid), and the anti-mouse CD25 antibody was then immobilized using the 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide reaction. Immobilization of the antibody on the PE mesh was confirmed by immunostaining. The CD25-PE mesh could effectively and selectively capture CD25-positive cells through antigen-antibody interactions when the CD25-PE mesh was incubated with a suspension of mouse spleen cells, including CD25-positive cells. In addition, implantation of the CD25-PE mesh into mice subcutaneously demonstrated the Treg-capturing ability of the CD25-PE mesh with only a weak inflammatory reaction. In tumor-bearing mice, tumor growth was suppressed by subcutaneous implantation of the CD25-PE mesh near the tumor for 1 week. These results suggested that the anti-CD25 antibody-immobilized material could capture Tregs in vivo and inhibit tumor proliferation in a limited tumor-bearing mouse model. Further research is needed to facilitate cancer immunotherapy using implantable anti-CD25 antibody-immobilized material as a Treg-capturing device.
The purpose of this study was to evaluate the physical and chemical properties of engineering plastics processed using supercritical CO2. First, we prepared disk-shaped test pieces via a general ...molding process, which were plasticized using supercritical CO2 at temperatures lower than the glass-transition points of engineering plastics. Amorphous polymers were plasticized, and their molecular weight remained nearly unchanged after treatment with supercritical CO2. The mechanical strength significantly decreased despite the unchanged molecular weight. The surface roughness and contact angle increased slightly, and electrical properties such as the rate of charging decreased significantly. These results suggest that supercritical CO2 could be used for a new molding process performed at lower temperatures than those used in general molding processes, according to the required properties.
Abstract To prepare acellular corneal scaffold, we used high-hydrostatic pressurization (HHP) to decellularize porcine cornea. The HHP method disrupts cells by hydrostatic pressurization, and then ...the disrupted cells' components are removed by washing with a cell culture medium. Porcine corneas were hydrostatically pressed at 980 MPa at 10 or 30 °C for 10 min to make them opaque. There was no change in the thickness of the corneas immediately after the pressurization, but they swelled during the washing process. The cornea swelling caused by HHP was suppressed when medium containing 3.5% w/v dextran was used. For H-E staining of the cornea decellularized with the HHP method, the complete removal of corneal cells was confirmed. Furthermore, when the corneas were immersed in glycerol for 1 hour, their optical properties were restored to those of native corneas. In an animal study, when acellular porcine corneas were implanted into rabbit cornea, no immune reaction occurred and the turbid corneas became clear. The decellularized corneas obtained through HHP could be useful as a corneal scaffold for tissue regeneration.
Purpose This study aimed to investigate the effect of cognitive tasks on the center-of-foot pressure (COP) displacements and brain activity during single leg stance (SLS) in older people. ...Participants and Methods This study included 25 healthy older (age, 68.8 ± 4.9 years) and 25 young (age, 21.0 ± 0.9 years) participants. Participants performed SLS for 35 s under a single-task (ST) and three dual-tasks (DTs), namely verbal, subtraction, and recall tasks. We measured the total length of COP (COP_TL) and change in oxygenated hemoglobin (HbO2) levels during SLS under four tasks. Results There were no differences in COP_TL and HbO2 levels in the young group, whereas COP_TL in the recall task was significantly longer than in ST in the older group. In the comparisons of the DTc (the relative change of DT to ST), no differences were found among three DTs in the young group, whereas the DTc of COP_TL in the recall task was significantly higher than that in the verbal task in the older group. Regarding HbO2, no differences were observed among the four tasks in both groups. Conclusion These results suggest that SLS combined with a recall task may be useful for fall risk screening in healthy older individuals.
Monte Carlo (MC)‐based refinement software to analyze the atomic arrangements of perovskite oxide ultrathin films from the crystal truncation rod intensity is developed on the basis of Bayesian ...inference. The advantages of the MC approach are (i) it is applicable to multi‐domain structures, (ii) it provides the posterior probability of structures through Bayes' theorem, which allows one to evaluate the uncertainty of estimated structural parameters, and (iii) one can involve any information provided by other experiments and theories. The simulated annealing procedure efficiently searches for the optimum model owing to its stochastic updates, regardless of the initial values, without being trapped by local optima. The performance of the software is examined with a five‐unit‐cell‐thick LaAlO3 film fabricated on top of SrTiO3. The software successfully found the global optima from an initial model prepared by a small grid search calculation. The standard deviations of the atomic positions derived from a dataset taken at a second‐generation synchrotron are ±0.02 Å for metal sites and ±0.03 Å for oxygen sites.
Reverse Monte Carlo software to analyze the atomic arrangements of perovskite oxide ultrathin films from the crystal truncation rod intensity is developed on the basis of Bayesian inference.
Decellularized tissues are widely used as promising materials in tissue engineering and regenerative medicine. Research on the microstructure and components of the extracellular matrix (ECM) was ...conducted to improve the current understanding of decellularized tissue functionality. The presence of matrix-bound nanovesicles (MBVs) embedded within the ECM was recently reported. Results of a previous experimental investigation revealed that decellularized tissues prepared using high hydrostatic pressure (HHP) exhibited good in vivo performance. In the current study, according to the hypothesis that MBVs are one of the functional components in HHP-decellularized tissue, we investigated the extraction of MBVs and the associated effects on vascular endothelial cells. Using nanoparticle tracking assay (NTA), transmission electron microscopy (TEM), and RNA analysis, nanosized (100–300 nm) and membranous particles containing small RNA were detected in MBVs derived from HHP-decellularized small intestinal submucosa (SIS), urinary bladder matrix (UBM), and liver. To evaluate the effect on the growth of vascular endothelial cells, which are important in the tissue regeneration process, isolated SIS-derived MBVs were exposed to vascular endothelial cells to induce cell proliferation. These results indicate that MBVs can be extracted from HHP-decellularized tissues and may play a significant role in tissue remodeling.
Single crystals of BiFe0.9Co0.1O3 and BiFe0.892Mn0.008Co0.1O3, room temperature ferroelectric ferromagnets, were successfully grown by a flux method at a high pressure of 3 GPa. Remanent ...magnetization measurements along 18 crystallographic directions revealed the existence of a magnetic easy plane perpendicular to the electric polarization. Reorientation of the magnetic easy plane occurred in connection with 71° ferroelectric switching by applying an electric field. This is the first demonstration of an electric field affecting the local magnetic moment of Co-substituted BiFeO3.
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