University of Electro-Communications

Carbapenem-resistant Acinetobacter baumannii (CRAb) is designated by the World Health Organization as a critical priority pathogen, and most clinical CRAb isolates are multidrug-resistant (MDRA). However, an in vivo mouse imaging model of infection using clinical MDRA isolates has not been curated. Using antibiotic resistance genes as plasmid selection markers is incompatible with antimicrobial drug evaluation and prevents their application to MDRA isolates. To overcome this limitation, we constructed a firefly luciferase plasmid using tellurite resistance genes as non-antibiotic selection markers, enabling luminescence in multiple clinical MDRA isolates without altering susceptibility. Using a mouse pneumonia model and near-infrared luciferin derivative (TokeOni), we achieved noninvasive visualization of lung colonization by clinical MDRA isolates. Luminescence dynamics during treatment mirrored the in vitro minimum inhibitory concentration and survival outcomes, providing a therapeutic response readout. This platform overcomes a major bottleneck in MDR pathogen imaging and supports the evaluation of infection dynamics and drug efficacy.

Purpose This study proposes a problem-solving framework grounded in Total Quality Management (TQM) to enhance preparedness for future pandemics. By comparing COVID-19 responses in Japan, United States, Taiwan, and India, it examines how TQM principles can strengthen adaptive governance and public health resilience. Design/methodology/approach A comparative analysis of infection trajectories, policies, and behavioral responses was conducted across four countries/regions with different governance structures. TQM principles, particularly process integration and preventive design, were applied to explain variations in infection and mortality rates, and to systematize quality elements and risk governance frameworks in daily social processes. Findings Timely, science-aligned leadership, and structured social processes were essential for effective pandemic response. Taiwan’s early cross-sectoral coordination fostered trust and compliance. In Japan, bureaucratic decision-making delayed timely actions, while in United States, fragmented federal-state leadership hindered policy consistency. India’s socio-economic constraints limited process control. These cross-national contrasts demonstrate that institutional maturity, advanced healthcare infrastructure, and abundant public resources alone do not guarantee effective crisis management. Rather, TQM principles – science-based leadership, process assurance, digital risk communication, and protection of high-risk populations – are key to ensuring coherent governance and behavioral compliance under uncertainty. Originality/value This paper reconceptualizes pandemic preparedness as a quality assurance challenge. By integrating TQM with digital governance and risk stratification, it presents a structured, feedback-driven model for minimizing risk, promoting equity, and reinforcing resilience in public health systems.

Perovskite quantum dot (QD) light-emitting diodes (LEDs) typically exhibit a trade-off between emission efficiency and spectral stability. This compromise primarily arises from nonradiative recombination losses attributed to Pb2+ defects, halide phase segregation, and self-doping effects. In this study, we employ an environmentally friendly ligand exchange strategy utilizing short-chain selenium-containing L-seleno-methylselenocysteine (L-SeMSC) to passivate defects in perovskite QDs and replace the high-resistive long-chain ligands of oleate and oleylammonium. Theoretical and experimental findings indicate that the oxygen lone pair electrons from the carboxyl group in L-SeMSC effectively coordinate with Pb2+ defects on the surface of CsPb(Br/I)3 QDs, while the positively charged amino group inhibits halide ion migration. This coordination significantly enhances the photoluminescence quantum yield, thermal and air stability, and electroluminescence performance. The optimal LED achieves a maximum brightness of 2222.4 cd m−2 and an external quantum efficiency (EQE) of 17.18% at 654 nm, surpassing the performance of the control device, which exhibits a maximum brightness of 524.2 cd m−2 and an EQE of 8.94%, characterized by unstable luminescence emission. This study underscores the critical role of selenium-containing amino acids in enhancing the performance and stability of perovskite QD LEDs.

Auroral arcs in the high latitude are frequently observed during periods of northward interplanetary magnetic field (IMF). However, their generation mechanisms are not yet fully understood, due to the limited availability of simultaneous in-situ and optical auroral observations. In this talk, we present observations of recurrent tailward-propagating auroral arcs in the dawnside during a period of northward IMF. THEMIS satellites located near the dawnside magnetopause in the equatorial plane observed strong fluctuations in magnetic field and plasma parameters with periods of 5–7 minutes, suggesting the presence of surface waves or ULF waves. Subsequently, shorter-period fluctuations of 2-3 minutes were observed for an hour, which may indicate the development of Kelvin–Helmholtz instability (KHI). During these intervals, a ground-based all-sky imager detected recurrent auroral arcs detached from the poleward boundary of the auroral oval, with a period of 5–10 minutes, propagating predominantly tailward. DMSP observations revealed multiple auroral arcs on the dawnside, accompanied by electron precipitation associated with paired upward and downward field-aligned currents. Based on these coordinated space- and ground-based observations, we discuss several possible generation mechanisms for the observed auroral arcs, including surface waves, ULF waves, and KHI.

Sub-terahertz astronomy requires instruments capable of simultaneous observations across multiple spectral bands, motivating the development of broadband anti-reflection coatings (ARCs). We investigated low-loss dielectrics with refractive indices suitable for multilayer ARCs on polyethylene optical elements and identified candidates that partially meet the requirements. To address the remaining gaps in available refractive indices, we applied dielectric multilayer synthesis by combining newly identified thin materials with controlled bonding to realize the required effective refractive indices. As a result, the fabricated five-layer ARC achieved reflection losses of 0.2% (average) and 3.2% (maximum) over 130-710GHz.