The chemical characterization of the heaviest elements at the farthest reach of the periodic table (PT) and the classification of these elements in the PT are undoubtedly crucial and challenging ...subjects in chemical and physical sciences. The elucidation of the influence of relativistic effects on their outermost electronic configuration is also a critical and fascinating aspect. However, the heaviest elements with atomic numbers Z ≳ 100 must be produced at accelerators using nuclear reactions of heavy ions and target materials. Therefore, production rates for these elements are low, and their half-lives are as short as a few seconds to a few minutes; they are usually available in a quantity of only a few atoms at a time. Here, we review some highlighted studies on heavy actinide and light transactinide chemical characterization performed at the Japan Atomic Energy Agency tandem accelerator facility. We discuss briefly the prospects for future studies of the heaviest elements.
This study demonstrated the antiviral properties of copper iodide (CuI) nanoparticles against the non-enveloped virus feline calicivirus (FCV) as a surrogate for human norovirus. The effect of CuI ...nanoparticles on FCV infectivity to Crandell-Rees feline kidney (CRFK) cells was elucidated. The infectivity of FCV to CRFK cells was greatly reduced by 7 orders of magnitude at 1000μgml−1 CuI nanoparticles. At the conditions, electron spin resonance (ESR) analysis proved hydroxyl radical production in CuI nanoparticle suspension. Furthermore, amino acid oxidation in the viral capsid protein of FCV was determined by nanoflow liquid chromatography-mass spectrometric (nano LC-MS) analysis. The use of CuI nanoparticles showed extremely high antiviral activity against FCV. The high antiviral property of CuI nanoparticles was attributed to Cu+, followed by ROS generation and subsequent capsid protein oxidation. CuI nanoparticles could be proposed as useful sources of a continuous supply of Cu+ ions for efficient virus inactivation. Furthermore, this study brings new insights into toxic actions of copper iodide nanoparticles against viruses.
Perceptions of yellowing, aging and dirtiness in textile products affect consumer satisfaction and sustainable use. Customers often decide whether to use a product based on its color, even if it is ...functionally usable. It is difficult to avoid the yellowing of objects; consequently, many scales have been developed to evaluate this phenomenon. This study examined consumers' perceptions of various colors associated with yellowing, aging and dirtiness using the terms “whitish,” “yellowish,” “yellowing,” “yellowed,” “aged” and “dirty,” and the differences between them. The applicability of the commonly used yellowness index (YI) was also examined. The results showed perceptual similarities among “yellowish,” “yellowing” and “yellowed,” but there were also notable differences. The boundary between “whitish” and “yellowish” was clear, but near-white colors were included for “yellowing” and “yellowed” colors. The yellow component was a major factor in “aged” and “dirty,” but not the only characteristic. Similarities and differences between “aged” and “dirty” perceptions were demonstrated. The “aged” colors were distributed in a wider range than the “dirty” colors, and most of the “dirty” colors were within the “aged” color range. This suggests that even colors perceived as “aged” are not necessarily “dirty.” The YI did not adequately assess the perceptions. Consumers' perceptions of colors ranged more widely than those of the YI. As the need for sustainability and creating products that meet consumers' needs for long-term use continues to grow, it would be valuable to understand not only yellow-associated colors but also “aged” and “dirty” and their differences.
General relations for nonequilibrium spin transport at a magnetic junction between a normal metal and a ferromagnetic insulator are derived from the quantum fluctuation theorem. They include the ...extended Onsager relations between the spin conductance and the spin-current noise that hold for nonequilibrium states driven by an external current. These relations are valid for a general setup of spin Hall magnetoresistance (SMR) when the main contribution is due to the interfacial spin conductance. Unidirectional spin Hall magnetoresistance (UMR) in insulating ferromagnetic junctions can be understood in a similar way. Therefore, our work can provide a comprehensive viewpoint for understanding of SMR and UMR in insulating ferromagnetic junctions. Our result also predicts relations for higher-order coefficients with respect to the external current in terms of higher-order cumulants in a unified framework.
•General relations were derived from the fluctuation theorem for nonequilibrium spin transport at a normal-metal/ferromagnetic-insulator interface.•The obtained formulas include the extended Onsager relation that holds between the spin conductance and the spin-current noise.•Our results will attribute to comprehension of the unidirectional spin Hall magnetoresistance in insulating ferromagnetic junctions.
With the recent surge of affordable, high-performance virtual reality (VR) headsets, there is unlimited potential for applications ranging from education, to training, to entertainment, to fitness ...and beyond. As these interfaces continue to evolve, passive user-state monitoring can play a key role in expanding the immersive VR experience, and tracking activity for user well-being. By recording physiological signals such as the electroencephalogram (EEG) during use of a VR device, the user's interactions in the virtual environment could be adapted in real-time based on the user's cognitive state. Current VR headsets provide a logical, convenient, and unobtrusive framework for mounting EEG sensors. The present study evaluates the feasibility of passively monitoring cognitive workload via EEG while performing a classical n-back task in an interactive VR environment. Data were collected from 15 participants and the spatio-spectral EEG features were analyzed with respect to task performance. The results indicate that scalp measurements of electrical activity can effectively discriminate three workload levels, even after suppression of a co-varying high-frequency activity.
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•CuOx/3Al2O3·2SiO2 suppressed N2O/NOx production from the catalytic NH3 combustion.•CuOx/3Al2O3·2SiO2 after thermal aging was shown to contain highly dispersed CuAl2O4.•During the ...combustion, aged CuOx/3Al2O3·2SiO2 preserved the structure of CuAl2O4.•The activity is closely associated with the reducibility of supported CuOx particles.
Although NH3 has recently been regarded as a renewable and carbon-free energy source, NH3 fuel has a high ignition temperature and its use results in the production of N2O/NOx. To overcome these issues, in this work, we focused on a novel catalytic combustion system and copper oxides (CuOx) catalysts supported on aluminum silicates (Al6O13Si2, 3Al2O3·2SiO2, 3A2S) and silicon oxides (SiO2). The preparation methods for 3A2S as a support material were optimized to achieve high catalytic NH3 combustion activity and high N2 (low N2O/NO) selectivity. Because the CuOx supported on 3A2S prepared by an alkoxide method and subsequent calcination at 1200 °C for 5 h in air exhibited high catalytic performance for NH3 combustion, the properties of the catalyst in addition to CuOx/SiO2 thermally aged at 900 °C for 100 h in air were also evaluated using high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray mapping, operando X-ray absorption fine structure analysis, X-ray photoelectron spectroscopy, and gas adsorption techniques. Our findings suggest that the catalytic NH3 combustion activity, NO selectivity, and N2O selectivity are closely associated with the reducibility (dispersion) of CuOx, local structures around Cu, fraction of the oxidation state (Cu2+), and adsorption species of NH3 (NH, imide). Finally, we propose a reaction mechanism for catalytic NH3 combustion over not only CuOx/3A2S but also CuOx/SiO2.
Peripheral blood (PB) contains several types of stem/progenitor cells, including hematopoietic stem and endothelial progenitor cells. We identified a population positive for both the pluripotent ...surface marker SSEA-3 and leukocyte common antigen CD45 that comprises 0.04% ± 0.003% of the mononuclear cells in human PB. The average size of the SSEA-3(+)/CD45(+) cells was 10.1 ± 0.3 µm and ∼22% were positive for CD105, a mesenchymal marker; ∼85% were positive for CD19, a B cell marker; and ∼94% were positive for HLA-DR, a major histocompatibility complex class II molecule relevant to antigen presentation. These SSEA-3(+)/CD45(+) cells expressed the pluripotency markers Nanog, Oct3/4, and Sox2, as well as sphingosine-1-phosphate (S1P) receptor 2, and migrated toward S1P, although their adherence and proliferative activities in vitro were low. They expressed NeuN at 7 d, Pax7 and desmin at 7 d, and alpha-fetoprotein and cytokeratin-19 at 3 d when supplied to mouse damaged tissues of the brain, skeletal muscle and liver, respectively, suggesting the ability to spontaneously differentiate into triploblastic lineages compatible to the tissue microenvironment. Multilineage-differentiating stress enduring (Muse) cells, identified as SSEA-3(+) in tissues such as the bone marrow and organ connective tissues, express pluripotency markers, migrate to sites of damage via the S1P-S1P receptor 2 system, and differentiate spontaneously into tissue-compatible cells after homing to the damaged tissue where they participate in tissue repair. After the onset of acute myocardial infarction and stroke, patients are reported to have an increase in the number of SSEA-3(+) cells in the PB. The SSEA-3(+)/CD45(+) cells in the PB showed similarity to tissue-Muse cells, although with difference in surface marker expression and cellular properties. Thus, these findings suggest that human PB contains a subset of cells that are distinct from known stem/progenitor cells, and that CD45(+)-mononuclear cells in the PB comprise a novel subpopulation of cells that express pluripotency markers.
DNA methylation is globally reprogrammed after fertilization, and as a result, the parental genomes have similar DNA-methylation profiles after implantation except at the germline differentially ...methylated regions (gDMRs). We and others have previously shown that human blastocysts might contain thousands of transient maternally methylated gDMRs (transient mDMRs), whose maternal methylation is lost in embryonic tissues after implantation. In this study, we performed genome-wide allelic DNA methylation analyses of purified trophoblast cells from human placentas and, surprisingly, found that more than one-quarter of the transient-in-embryo mDMRs maintained their maternally biased DNA methylation. RNA-sequencing-based allelic expression analyses revealed that some of the placenta-specific mDMRs were associated with expression of imprinted genes (e.g., TIGAR, SLC4A7, PROSER2-AS1, and KLHDC10), and three imprinted gene clusters were identified. This approach also identified some X-linked gDMRs. Comparisons of the data with those from other mammals revealed that genomic imprinting in the placenta is highly variable. These findings highlight the incomplete erasure of germline DNA methylation in the human placenta; understanding this erasure is important for understanding normal placental development and the pathogenesis of developmental disorders with imprinting effects.
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