Pusan National University

About: Pusan National University is a education organization based out in Busan, South Korea. It is known for research contribution in the topics: Catalysis & Population. The organization has 24124 authors who have published 45054 publications receiving 819356 citations. The organization is also known as: Busan National University & Pusan University.

Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea.

Abstract: Importance There is limited information describing the full spectrum of coronavirus disease 2019 (COVID-19) and the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in children. Objective To analyze the full clinical course and the duration of SARS-CoV-2 RNA detectability in children confirmed with COVID-19 in the Republic of Korea, where rigorous public health interventions have been implemented. Design, Setting, and Participants This case series of children with COVID-19 was conducted in 20 hospitals and 2 nonhospital isolation facilities across the country from February 18, 2020, to March 31, 2020. Children younger than 19 years who had COVID-19 were included. Exposures Confirmed COVID-19, detected via SARS-CoV-2 RNA in a combined nasopharyngeal and oropharyngeal swab or sputum by real-time reverse transcription–polymerase chain reaction. Main Outcomes and Measures Clinical manifestations during the observation period, including the time and duration of symptom occurrence. The duration of SARS-CoV-2 RNA detection was also analyzed. Results A total of 91 children with COVID-19 were included (median [range] age, 11 [0-18] years; 53 boys [58%]). Twenty children (22%) were asymptomatic during the entire observation period. Among 71 symptomatic cases, 47 children (66%) had unrecognized symptoms before diagnosis, 18 (25%) developed symptoms after diagnosis, and only 6 (9%) were diagnosed at the time of symptom onset. Twenty-two children (24%) had lower respiratory tract infections. The mean (SD) duration of the presence of SARS-CoV-2 RNA in upper respiratory samples was 17.6 (6.7) days. Virus RNA was detected for a mean (SD) of 14.1 (7.7) days in asymptomatic individuals. There was no difference in the duration of virus RNA detection between children with upper respiratory tract infections and lower respiratory tract infections (mean [SD], 18.7 [5.8] days vs 19.9 [5.6] days;P = .54). Fourteen children (15%) were treated with lopinavir-ritonavir and/or hydroxychloroquine. All recovered, without any fatal cases. Conclusions and Relevance In this case series study, inapparent infections in children may have been associated with silent COVID-19 transmission in the community. Heightened surveillance using laboratory screening will allow detection in children with unrecognized SARS-CoV-2 infection.

Recent progress of advanced energy storage materials for flexible and wearable supercapacitor: From design and development to applications

Abstract: Wearable electronic devices, such as electrical sensors, flexible displays, and health monitors have gained considerable attention and experienced rapid progress. Recently, the progress of flexible and wearable supercapacitors (SCs) have received considerable attention due to their ease of fabrication, low cost, flexible integration into textiles, long cycle life, fast charging/discharging, high efficiency, and capability to bridge the energy/power gap between conventional capacitors and batteries/fuel cells. In this context, the recent progress and achievements of flexible and wearable supercapacitors are presented, especially, the rational design and synthesis of novel nanostructured electrode materials on various flexible-based substrates, such as, carbon cloth, graphene coated fabric, silver coated fabric, nickel coated fabric, copper/nickel coated polyester fabric (CNF), etc. are summarized. The latest representative techniques and active materials of recently developed wearable supercapacitors with superior performance are summarized. Lastly, the current challenges, and future research directions and perspective in optimizing and developing the energy storage performance and function of flexible and wearable supercapacitors for their practical applications are addressed.

Current Trends of the Incidence and Pathological Diagnosis of Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs) in Korea 2000-2009: Multicenter Study.

Abstract: Purpose As a result of various independently proposed nomenclatures and classifications, there is confusion in the diagnosis and prediction of biological behavior of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A comprehensive nationwide study is needed in order to understand the biological characteristics of GEP-NETs in Korea. Materials and methods We collected 4,951 pathology reports from 29 hospitals in Korea between 2000 and 2009. Kaplan-Meier survival analysis was used to determine the prognostic significance of clinicopathological parameters. Results Although the GEP-NET is a relatively rare tumor in Korea, its incidence has increased during the last decade, with the most significant increase found in the rectum. The 10-year survival rate for well-differentiated endocrine tumor was 92.89%, in contrast to 85.74% in well differentiated neuroendocrine carcinoma and 34.59% in poorly differentiated neuroendocrine carcinoma. Disease related death was most common in the biliary tract (62.2%) and very rare in the rectum (5.2%). In Kaplan-Meier survival analysis, tumor location, histological classification, extent, size, mitosis, Ki-67 labeling index, synaptophysin expression, lymphovascular invasion, perineural invasion, and lymph node metastasis showed prognostic significance (p Conclusion The incidence of GEP-NET in Korea has shown a remarkable increase during the last decade, however, the distribution of tumors in the digestive system differs from that of western reports. Assessment of pathological parameters, including immunostaining, is crucial in understanding biological behavior of the tumor as well as predicting prognosis of patients with GEP-NET.

Extracting maximum capacity from Ni-rich Li[Ni0.95Co0.025Mn0.025]O2 cathodes for high-energy-density lithium-ion batteries

Abstract: The electrochemical properties of Li[Ni0.95Co0.025Mn0.025]O2, the composition of which is similar to that of LiNiO2, were evaluated to test whether the beneficial effect of Co and Mn addition persists at this extremely Ni-rich layered Li[NixCoyMn1−x−y]O2 (NCM) cathode. Despite their low concentrations, the presence of Co and Mn ions notably improved the cycling and thermal stability of Li[Ni0.95Co0.025Mn0.025]O2 over that of LiNiO2 (initial discharge capacity of 238 mA h g−1 with 85% retention after 100 cycles when cycled at 4.3 V for Li[Ni0.95Co0.025Mn0.025]O2vs. 248 mA h g−1 but with 74% retention for LiNiO2). It was also shown that the capacity degradation of highly Ni-enriched NCM cathodes appears to arise from the anisotropic volume change during Li removal/insertion, which was aggravated by the formation of the H3 phase in the delithiated state. The particle core was especially susceptible to structural damage from the accumulation of the intrinsic internal strain, which led to the initiation and propagation of microcracks from the particle core. The microcracks subsequently exposed the particle core to electrolyte damage for a prolonged period in the delithiated state, leading to eventual disintegration of the secondary particles. It appears that protecting the particle core (or interparticle boundaries) may help in extending the cycling stability of Ni-rich NCM cathodes, especially for those with very high Ni compositions.