We report the first 7,755 patients with confirmed COVID-19 in Korea as of March 12 th , 2020. A total of 66 deaths have been recorded, giving a case fatality proportion of 0.9%. Older people, and those with comorbidities were at a higher risk of a fatal outcome. The highest number of cases of COVID-19 were in Daegu, followed by Gyeongbuk. This summary may help to understand the disease dynamics in the early phase of the COVID-19 outbreaks, and may therefore, guide future public health measures.

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Exploring bifunctional electrocatalysts to lower the activation energy barriers for sluggish electrochemical reactions for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of great importance in achieving lower energy consumption and higher conversion efficiency for future energy conversion and storage system. Despite the excellent performance of precious metal-based electrocatalysts for OER and ORR, their high cost and scarcity hamper their large-scale industrial application. As alternatives to precious metal-based electrocatalysts, the development of earth-abundant and efficient catalysts with excellent electrocatalytic performance in both the OER and the ORR is urgently required. Herein, we report a core–shell CoFeS2@CoS2 heterostructure entangled with carbon nanotubes as an efficient bifunctional electrocatalyst for both the OER and the ORR. The CoFeS2@CoS2 nanocubes entangled with carbon nanotubes show superior electrochemical performance for both the OER and the ORR: a potential of 1.5 V (vs. RHE) at a current density of 10 mA cm−2 for the OER in alkaline medium and an onset potential of 0.976 V for the ORR. This work suggests a processing methodology for the development of the core–shell heterostructures with enhanced bifunctional performance for both the OER and the ORR.

Achieving carbon neutrality is important to solve environmental problems and thus requires decarbonizing manufacturing processes to reduce greenhouse gas emissions. The firing of ceramics, including calcination and sintering, is a typical fossil fuels-driven manufacturing process that requires large power consumption. Although the firing process in manufacturing ceramics cannot be eliminated, an effective firing strategy to reduce processing steps can be a choice to lower power consumption. Herein, we suggest a one-step solid solution reaction (SSR) route to manufacture (Ni, Co, and Mn)O4 (NMC) electroceramics for their application in temperature sensors with negative temperature coefficient (NTC). Additionally, the effect of the one-step SSR route on the electrical properties of the NMC is investigated. Similar to the NMC prepared using the two-step SSR route, spinel structures with dense microstructure are observed in the NMC prepared via the one-step SSR route. Based on the experimental results, the one-step SSR route can be considered as one of the effective processing techniques with less power consumption to manufacture electroceramics.