ObjectivesThe outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the Republic of Korea started from the index case who developed fever after returning from the Middle East. He infected 26 cases in Hospital C, and consecutive nosocomial transmission proceeded throughout the nation. We provide an epidemiologic description of the outbreak, as of July 2015.MethodsEpidemiological research was performed by direct interview of the confirmed patients and reviewing medical records. We also analyzed the incubation period, serial interval, the characteristics of superspreaders, and factors associated with mortality. Full genome sequence was obtained from sputum specimens of the index patient.ResultsA total of 186 confirmed patients with MERS-CoV infection across 16 hospitals were identified in the Republic of Korea. Some 44.1% of the cases were patients exposed in hospitals, 32.8% were caregivers, and 13.4% were healthcare personnel. The most common presenting symptom was fever and chills. The estimated incubation period was 6.83 days and the serial interval was 12.5 days. A total of 83.2% of the transmission events were epidemiologically linked to five superspreaders, all of whom had pneumonia at presentation and contacted hundreds of people. Older age [odds ratio (OR) = 4.86, 95% confidence interval (CI) 1.90–12.45] and underlying respiratory disease (OR = 4.90, 95% CI 1.64–14.65) were significantly associated with mortality. Phylogenetic analysis showed that the MERS-CoV of the index case clustered closest with a recent virus from Riyadh, Saudi Arabia.ConclusionA single imported MERS-CoV infection case imposed a huge threat to public health and safety. This highlights the importance of robust preparedness and optimal infection prevention control. The lessons learned from the current outbreak will contribute to more up-to-date guidelines and global health security.
Efficient and cost‐effective bifunctional electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of vital importance in energy conversion and storage devices. Despite the recent progress in bifunctional oxygen electrocatalysts, their unbalanced and insufficient OER and ORR activities has continued to pose challenges for the practical application of such energy devices. The design of highly integrated, high‐performance, bifunctional oxygen electrocatalysts composed of highly graphitic nanoshells embedded in mesoporous carbon (GNS/MC) is reported. The GNS/MC exhibits very high oxygen electrode activity, which is one of the best performances among nonprecious metal bifunctional oxygen electrocatalysts, and substantially outperforms Ir‐ and Pt‐based catalysts. Moreover, the GNS/MC shows excellent durability for both OER and ORR. In situ X‐ray absorption spectroscopy and square wave voltammetry reveal the roles of residual Ni and Fe entities in enhancing OER and ORR activities. Raman spectra indicate highly graphitic, defect‐rich nature of the GNS/MC, which can contribute to the enhanced OER activity and to high stability for the OER and ORR. In aqueous Na–air battery tests, the GNS/MC air cathode‐based cell exhibits superior performance to Ir/C‐ and Pt/C‐based batteries. Significantly, the GNS/MC‐based cell demonstrates the first example of rechargeable aqueous Na–air battery.
Recent advances in the field of nanoscience have enabled the preparation of high‐surface‐area supported catalysts with precise control over the individual structural components. As such, a range of factors that affect the catalytic reactivity, such as the size, shape, and composition of the nanoparticles (NPs), have been identified. Herein, high‐surface‐area model catalysts that were based on colloidal Pd NPs and a hexagonally ordered mesoporous carbon support were prepared and the impact of various organic capping agents for the Pd NPs on their catalytic activity towards Suzuki coupling reactions was investigated. Colloidal Pd NPs (diameter: 3 nm) were synthesized with different organic capping agents, oleylamine (OA) and trioctylphosphine (TOP), and they were subsequently incorporated into the mesopores of CMK‐3 mesoporous carbon to yield OA‐Pd/CMK‐3 and TOP‐Pd/CMK‐3 nanocatalysts, respectively. The OA‐Pd/CMK‐3 catalyst was treated with acetic acid to generate a supported catalyst with surfactant‐free Pd NPs (OA‐Pd/CMK‐3‐A). Structural characterization revealed that the Pd NPs were uniformly dispersed throughout the mesopores of the CMK‐3 support and the particle size and crystallinity of the Pd NPs were preserved following the incorporation. All of the Pd/CMK‐3 nanocatalysts exhibited higher activity than commercial activated carbon supported Pd catalysts in Suzuki coupling reactions. The catalytic activities of the three Pd/CMK‐3 nanocatalysts were in the following order: OA‐Pd/CMK‐3‐A>OA‐Pd/CMK‐3>TOP‐Pd/CMK‐3. This result suggested that the presence and type of surfactants had a significant effect on the catalytic activity. The OA‐Pd/CMK‐3‐A catalyst also showed high activity for various substrates and good recycling ability in Suzuki coupling reactions.
Enterococcus hirae mainly causes infections in animals. It has been rarely encountered in humans and, in most such cases, it is considered to be a contaminant or resident flora. Since the first case of septicemia by E. hirae was reported in 1998, only two cases of acute pyelonephritis (APN) have been reported in Korea. We describe herein a case of APN caused by E. hirae in an 83-year-old man with a horseshoe kidney. Although E. hirae was isolated only from urine and not from the blood, we were able to diagnose it as the causative organism based on the patient's clinical findings, imaging study results, and risk factors including old age, benign prostatic hypertrophy, and a horseshoe kidney.
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