Research Organization for Information Science and Technology

In relativistic plasma expansion, a relative motion of plasma components causes absorption of spectral lines to be Doppler-shifted with respect to the emission line centers. The shift of spectral line can be of an order or exceeding the natural linewidth, leading to a significant reduction in self-absorption and optical thickness of the plasma. In this paper we experimentally examine the effect of femtosecond relativistic laser plasma expanding from both sides of the solid foil target. In an experiment, a hot plasma x-ray source in a 1–2 μm thin 4-chlorostyrene foil was created by high-contrast ∼ 1 × 1021 W/cm2 pulses delivered by the J-KAREN-P facility. In addition, the rear side of the target was heated by 1/100 of the main pulse power with a controlled few-nanosecond time delay. It is demonstrated that the high velocity of the downstream and upstream (from the rear side) plasma expansion essentially induces plasma transparency for K-shell emission from He-like chlorine ions dominating the ion charge distribution.

We investigate the impact of glycoform alterations on the dynamic structure of the human immunoglobulin G1 (IgG1) Fc region using integrated computational and experimental approaches. Four distinct IgG1-Fc glycoforms, varying in core fucosylation and nonreducing terminal galactosylation, were generated through a combination of cell engineering and in vitro enzymatic reactions. Stable-isotope-assisted NMR spectroscopy, incorporating both glycan and protein signals, revealed that galactosylation induces chemical shift perturbations extending from the glycan-protein interface to the CH2-CH3 domain boundary. Molecular dynamics simulations demonstrated that the absence of galactose enhances the mobility of both the glycan and the CH2 domain, broadening the conformational landscape of the Fc quaternary structure. This increased flexibility likely contributes to a greater entropic penalty upon binding to effector molecules, which constrain the Fc in an asymmetric conformation. Conversely, the effects of fucosylation are more localized, primarily influencing the dynamics of residues involved in Fcγ receptor IIIa binding. These findings provide atomic-level insights into the distinct yet synergistic mechanisms by which galactosylation and fucosylation modulate IgG1-Fc dynamics and effector functions, offering crucial information for the optimization of therapeutic antibodies.

Mg-based spinels (SP) such as MgM2O4 (M=Mn, Fe, Co) attract much interest as cathode material of future Mg-battery owing to those high capacities and high voltage. In the discharging process, Mg-based SP transforms into a rocksalt (RS) phase,MgM2O4 + Mg2+ + 2e- → Mg2M2O4.Due to low reversibility and slow Mg2+ kinetics, however, the Mg-battery with Mg-based SP cathode is not used for the practical applications. For the reversibility problem, the oxidative decomposition of solvent molecules is a crucial issue, which is the purpose of the present study.In this study, we performed theoretical simulations based on the density functional theory using Quantum Espresso code. The cutoff energy of a plane wave basis set is 35 Ry. The PBE functional of generalized gradient approximation with D3-version of van der Waals correction was employed. The isotropic on-side Coulomb term U was included for the 3d orbitals of Fe, Mn and Co. Both (001) orientation of SP and RS surfaces were considered since these surfaces have the lowest surface energy. While the long glyme molecules (such as G3, and G4) are used in the practical experiments, we employed the simplest ether molecule, i.e., diethyl ether as a model solvent molecule.First, we briefly mention the surface reconstruction of the SP surface. For the (001) surface of SP, the topmost Mg2+ ions which originally belong to the 16c site of bulk SP move to the 8a site which the Mg2+ ion sites of RS phase. Then, the surface of SP increases the RS-like feature and stabilizes. The growth of the RS phase on the SP surface was observed by TEM for MgMn2O4. In the following calculations, we used such reconstructed surface models for the adsorption and decomposition calculations.Next, we will discuss the solvent molecule decomposition. We consider the reaction energies of C-H dissociation and C-O dissociation for both SP and RS surfaces, which are defined by the difference of adsorption energies between the reactants and products.For the reactant, we put diethyl ether with the O atom of diethyl ether being the Mg or M ion sites. For the products, the H atom and -CH3 group are placed at the top of surface oxygen sites. We found that the C-H dissociation reactions on SP surfaces are exothermic irrespective of M elements, while the other reactions, i.e., the C-H dissociation reactions on SP and C-O dissociation on both SP and RS are endothermic.According to the charge analysis using Bader charge, the C-H dissociation can be understood as deprotonation rather than dehydrogenation. Then, an electron used in the C-H bond transfers to the M3+ ion. For the RS surface which does not contain M3+ ions, the electron cannot transfer to the RS surface. Therefore, the presence of M3+ in SP is important for this reaction. We also investigated the electronic structures of reactants and products by calculating LDOS and PDOS. The HOMO level of solvent is located 1.4-2.6 eV below the valence band maxima, suggesting that the adsorbates are hard to be oxidized directly. For the C-H dissociation reaction on SP surfaces, on the other hand, the valence band maxima shifts upward due to the reduction of M3+ ion. Since such energetically unstable occupied states can be easily oxidized, the electron at this level can be extracted as an oxidative current.[1] T. Kaneko, Y. Fujihara, H. Kobayashi and K. Sodeyama, Appl. Surf. Sci. 613, 156065 (2023).[2] T. Kaneko, Y. Fujihara, T. Mandai, H. Kobayashi and K. Sodeyama, Electrochemistry 23, 00087 (2024). Figure 1

Sinusoidal electric fields are applied to liquid crystals (LCs) across various frequencies ranging from 0.1 Hz to 10 kHz to investigate the oscillatory behavior of LC directors. In a 1.5 μm thick 5CB cell, a significant decline in refractive index change occurs in the frequency range greater than 10 Hz, in which the LC director cannot sufficiently follow the rapid fluctuations in field intensity. To evaluate the response speed of the LCs under sinusoidal electric fields, the cutoff frequency is introduced as a response indicator. Enhancement of the cutoff frequency can be achieved through conventional fast response techniques such as polymer-stabilized LCs.

The Republic of Moldova, one of Europe's poorest countries, also bears one of the highest burdens of rifampicin-resistant TB (RR-TB). To trace the patients' journey through TB in terms of the relationship with poverty and assess its determinants. This cross-sectional study used secondary data from a survey assessing catastrophic costs in RR-TB-affected households. Data were obtained from 430 RR-TB patients. The percentage of poor TB-affected households rose from 65% prior to TB to 86% after TB treatment completion (P < 0.001). Social factors leading to poverty were identified for each stage: diagnostic period (history of incarceration: cOR 2.3, 95% CI 1.1-5.2); treatment period (being unemployed or unofficially employed: cOR 6.7, 95% CI 4.3-10.0); and post-treatment (being married or cohabiting: cOR 5.7, 95% CI 2.9-11.0). Participants who had ≥3 members in their households were more likely to be poor at all TB stages: diagnostic period (cOR 5.7, 95% CI 3.7-8.8), treatment period (cOR 3.8, 95% CI 2.5-5.6) and post-treatment (cOR 7.2, 95% CI 3.6-14.3). The study identified risk factors associated with poverty at each stage of TB. These findings outline that innovative social protection policies are required to protect TB patients against poverty.

Purpose of ReviewThis review provides insights into resolving intergenerational issues related to the disposal of waste containing high amounts of uranium (uranium waste), from which distant future generations will have higher health risks than the current generation.Recent FindingsUranium (half-life: 4.5 billion years) produces various progeny radionuclides through radioactive decay over the long term, and its radioactivity, as the sum of its contributions, continues to increase for more than 100,000 years. In contrast to high-level radioactive wastes, protective measures, such as attenuation of radiation and confinement of radionuclides from the disposal facility, cannot work effectively for uranium waste. Thus, additional considerations from the perspective of intergenerational ethics are needed in the strategy for uranium waste disposal.SummaryThe current generation, which has benefited from the use and disposal of uranium waste, is responsible for protecting future generations from the potential risk of buried uranium beyond the lifetime of a disposal facility. Fulfilling this responsibility means making more creative efforts to convey critical information on buried materials to the distant future to ensure that future generations can properly take measures to reduce the harm by themselves in response to changing circumstances including people’s values.

In this study, we performed systematic search for dopants to stabilize the tetragonal structure of HfO<inf>2</inf> and ZrO<inf>2</inf> by using first-principles calculations. Whole impurity configurations within the supercell, more than 12,000 systems, are examined and the most stable configurations are assumed to be realized. We reveal the contributions of the dopants to the structural stability of tetragonal phase, and that Si or Ge significantly stabilize the tetragonal phase.

The oxygen reduction reaction (ORR) at the cathode is one of the critical bottlenecks in the energy conversion process in polymer electrolyte fuel cells (PEFCs) and metal–air batteries. An iron azaphthalocyanine unimolecular layer (Fe-AZUL) adsorbed onto a carbon substrate exhibited high ORR activity as an alternative of Pt supported on carbon black (Pt/C) electrocatalyst. We herein report the synthesis of various AzPc molecules with different peripheral structures and complex metals, as well as measurements of the ORR activities of catalysts containing the synthesized molecules and carbons. The catalytic activities were characterized by electrochemical analysis, density functional theory (DFT) calculations, and measurements of ionization potential (IP) values. From the results, the IP values on Ketjen Black (KB) were found to be one of the significant indicators for high ORR activities, providing a guideline for the development of high-performance electrocatalysts.