Fighting the COVID-19 pandemic: onsite mass workplace testing for COVID-19 in the Republic of Korea

The ongoing coronavirus disease 2019 (COVID-19) pandemic is causing tremendous damage globally. The Republic of Korea (ROK), a highly export-dependent nation, is a leader in the fight against the COVID-19 pandemic and coping well with the disaster. Like the drive-through COVID-19 testing, which reflects the brilliant flexibility of the Korean medical system, onsite mass workplace testing for COVID-19, which our hospital has been performing over the past few months, is a unique and valuable countermeasure. We believe it is time that the current health examination system for workers in the ROK considered the risk of transmissible diseases

Natural leaf-inspired solar water splitting system

We designed a monolithic artificial leaf that mimics a natural leaf; the artificial leaf has a crystalline silicon (c-Si) interdigitated back contact (collectively, c-Si IBC) structure. On the front-side of the artificial leaf, the c-Si module acts similar to chlorophyll in natural leaves, converting solar energy into photo-carriers. On the rear-side of the artificial leaf, a hydrogen and oxygen evolution catalyst converts the carriers into hydrogen; this occurs without blocking light, similar to the conversion of photo-carriers into chemical energy, which mostly occurs on the backside of natural leaves. The solar-to-hydrogen conversion efficiency of the c-Si IBC photoanode and artificial leaf was 10.1% and 8.4% respectively, which are higher than that of a natural leaf (0.1-1%)

Artificial optic-neural synapse for colored and color-mixed pattern recognition

Artificial neural networks can emulate the human vision because of their spike-based operation by employing memristors as synapses. Here, Seo et al. integrate synaptic and optical sensing functions in a single heterostructure, which enables accurate and energy-efficient recognition of colored patterns

Effective Schottky Barrier Height Lowering of Metal/n-Ge with a TiO₂/GeO₂ Interlayer Stack

A perfect ohmic contact formation technique for low-resistance source/drain (S/D) contact of germanium (Ge) n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) is developed. A metal–interlayer–semiconductor (M–I–S) structure with an ultrathin TiO₂/GeO₂ interlayer stack is introduced into the contact scheme to alleviate Fermi-level pinning (FLP), and reduce the electron Schottky barrier height (SBH). The TiO₂ interlayer can alleviate FLP by preventing formation of metal-induced gap states (MIGS) with its very low tunneling resistance and series resistance and can provide very small electron energy barrier at the metal/TiO₂ interface. The GeO₂ layer can induce further alleviation of FLP by reducing interface state density (<i>D</i>_it) on Ge which is one of main causes of FLP. Moreover, the proposed TiO₂/GeO₂ stack can minimize interface dipole formation which induces the SBH increase. The M–I–S structure incorporating the TiO₂/GeO₂ interlayer stack achieves a perfect ohmic characteristic, which has proved unattainable with a single interlayer. FLP can be perfectly alleviated, and the SBH of the metal/n-Ge can be tremendously reduced. The proposed structure (Ti/TiO₂/GeO₂/n-Ge) exhibits 0.193 eV of effective electron SBH which achieves 0.36 eV of SBH reduction from that of the Ti/n-Ge structure. The proposed M–I–S structure can be suggested as a promising S/D contact technique for nanoscale Ge n-channel transistors to overcome the large electron SBH problem caused by severe FLP

Body mass index is inversely associated with mortality in patients with acute kidney injury undergoing continuous renal replacement therapy

Background: Many epidemiologic studies have reported on the controversial concept of the obesity paradox. The presence of acute kidney injury (AKI) can accelerate energy-consuming processes, particularly in patients requiring continuous renal replacement therapy (CRRT). Thus, we aimed to investigate whether obesity can provide a survival benefit in this highly catabolic condition. Methods: We conducted an observational study in 212 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. The study end point was defined as death that occurred within 30 days after the initiation of CRRT. Results: Patients were categorized into three groups according to tertiles of body mass index (BMI). During ≥30 days after the initiation of CRRT, 39 patients (57.4%) in the highest tertile died, as compared with 58 patients (78.4%) in the lowest tertile (P = 0.02). In a multivariable analysis adjusted for cofounding factors, the highest tertile of BMI was significantly associated with a decreased risk of death (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.37–0.87; P = 0.01). This significant association remained unaltered for 60-day (HR, 0.64; 95% CI, 0.43–0.94; P = 0.03) and 90-day mortality (HR, 0.66; 95% CI, 0.44–0.97; P = 0.03). Conclusion: This study showed that a higher BMI confer a survival benefit over a lower BMI in AKI patients undergoing CRRT