• Clinical and Experimental Pediatrics
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• 제63권4호
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• pp.119-124
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• 2020

A cluster of severe pneumonia of unknown etiology in Wuhan City, Hubei province in China emerged in December 2019. A novel coronavirus named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was isolated from lower respiratory tract sample as the causative agent. The current outbreak of infections with SARS-CoV-2 is termed Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 rapidly spread into at least 114 countries and killed more than 4,000 people by March 11 2020. WHO officially declared COVID-19 a pandemic on March 11, 2020. There have been 2 novel coronavirus outbreaks in the past 2 decades. The outbreak of severe acute respiratory syndrome (SARS) in 2002-2003 caused by SARS-CoV had a case fatality rate of around 10% (8,098 confirmed cases and 774 deaths), while Middle East respiratory syndrome (MERS) caused by MERS-CoV killed 861 people out of a total 2,502 confirmed cases between 2012 and 2019. The purpose of this review is to summarize known-to-date information about SARS-CoV-2, transmission of SARS-CoV-2, and clinical features.

• 한국세라믹학회지
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• 제35권12호
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• pp.1329-1336
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• 1998

A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

• 생명과학회지
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• 제33권2호
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• pp.199-207
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• 2023

Post-COVID-19 시대에 다가올 전염병의 위협에 대비하기 위해 인간, 동물, 환경의 건강이 하나라는 One-health 개념에 기반한 연구가 필수적이다. 현재 인간의 SARS-CoV-2의 높은 감염률과 바이러스 부하로 인해 종을 뛰어넘는 감염이 확인되고 있다. 대표적으로 사람에서 밍크로의 전파 가능성이 확인되었고, 밀접 접촉 중에 사람에서 고양이로 전파가 가능할 것으로 추정되고 있다. 현재까지의 자료를 통해 가축류, 가금류에서의 감염 가능성이 낮은 것으로 보여지나 새로운 변이로 인해 감염이 확립된다면 인간의 식량 안보, 경제, 무역 등 다양한 분야에 파급 효과가 클 것으로 예측된다. 또한 SARS-CoV-2의 풍토화 전망과 반려동물로의 접근성이 높다는 점 등이 우려되는 상황이다. 바이러스의 진화는 동물 숙주에서 발생할 가능성이 높고, 다른 종에서 SARS-CoV-2가 확립되면 인간 집단에 바이러스가 다시 출현할 수 있는 중간 숙주 역할을 할 수도 있기 때문이다. SARS-CoV-2의 동물 감염에 대한 연구 데이터를 지속적으로 축적하여 빠른 대응이 필요하다고 생각된다. 또한 동물 감염에 대한 연구는 SARS-CoV-2 백신 및 치료제 연구에 사용되는 동물 모델의 개발 등을 포함한 다방면에서 중요하다. 따라서 본 연구에서는 SARS-CoV-2의 동물 감염에 대해 역학 검토 및 대응 전략을 One-health 관점에서 접근하여 분석하였다.

• Molecules and Cells
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• 제44권6호
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• pp.401-407
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• 2021

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which is an ongoing pandemic disease. SARS-CoV-2-specific CD4⁺ and CD8⁺ T-cell responses have been detected and characterized not only in COVID-19 patients and convalescents, but also unexposed individuals. Here, we review the phenotypes and functions of SARS-CoV-2-specific T cells in COVID-19 patients and the relationships between SARS-CoV-2-specific T-cell responses and COVID-19 severity. In addition, we describe the phenotypes and functions of SARS-CoV-2-specific memory T cells after recovery from COVID-19 and discuss the presence of SARS-CoV-2-reactive T cells in unexposed individuals and SARS-CoV-2-specific T-cell responses elicited by COVID-19 vaccines. A better understanding of T-cell responses is important for effective control of the current COVID-19 pandemic.

• IMMUNE NETWORK
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• 제21권1호
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• pp.2.1-2.11
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• 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), an ongoing pandemic disease. In the current review, we describe SARS-CoV-2-specific CD4⁺ and CD8⁺ T-cell responses in acute and convalescent COVID-19 patients. We also discuss the relationships between COVID-19 severity and SARS-CoV-2-specific T-cell responses and summarize recent reports regarding SARS-CoV-2-reactive T cells in SARS-CoV-2-unexposed individuals. These T cells may be cross-reactive cells primed by previous infection with human common-cold coronaviruses. Finally, we outline SARS-CoV-2-specific T-cell responses in the context of vaccination. A better understanding of SARS-CoV-2-specific T-cell responses is needed to develop effective vaccines and therapeutics.

• IMMUNE NETWORK
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• 제21권1호
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• pp.3.1-3.16
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• 2021

Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide since its outbreak in December 2019, and World Health Organization declared it as a pandemic on March 11, 2020. SARS-CoV-2 is highly contagious and is transmitted through airway epithelial cells as the first gateway. SARS-CoV-2 is detected by nasopharyngeal or oropharyngeal swab samples, and the viral load is significantly high in the upper respiratory tract. The host cellular receptors in airway epithelial cells, including angiotensin-converting enzyme 2 and transmembrane serine protease 2, have been identified by single-cell RNA sequencing or immunostaining. The expression levels of these molecules vary by type, function, and location of airway epithelial cells, such as ciliated cells, secretory cells, olfactory epithelial cells, and alveolar epithelial cells, as well as differ from host to host depending on age, sex, or comorbid diseases. Infected airway epithelial cells by SARS-CoV-2 in ex vivo experiments produce chemokines and cytokines to recruit inflammatory cells to target organs. Same as other viral infections, IFN signaling is a critical pathway for host defense. Various studies are underway to confirm the pathophysiological mechanisms of SARS-CoV-2 infection. Herein, we review cellular entry, host-viral interactions, immune responses to SARS-CoV-2 in airway epithelial cells. We also discuss therapeutic options related to epithelial immune reactions to SARS-CoV-2.

• Molecules and Cells
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• 제43권11호
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• pp.953-963
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• 2020

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an infectious disease with multiple severe symptoms, such as fever over 37.5℃, cough, dyspnea, and pneumonia. In our research, microRNAs (miRNAs) binding to the genome sequences of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory-related coronavirus (MERS-CoV), and SARS-CoV-2 were identified by bioinformatic tools. Five miRNAs (hsa-miR-15a-5p, hsa-miR-15b-5p, hsa-miR-195-5p, hsa-miR-16-5p, and hsa-miR-196a-1-3p) were found to commonly bind to SARS-CoV, MERS-CoV, and SARS-CoV-2. We also identified miRNAs that bind to receptor proteins, such as ACE2, ADAM17, and TMPRSS2, which are important for understanding the infection mechanism of SARS-CoV-2. The expression patterns of those miRNAs were examined in hamster lung samples infected by SARS-CoV-2. Five miRNAs (hsa-miR-15b-5p, hsa-miR-195-5p, hsa-miR-221-3p, hsa-miR-140-3p, and hsa-miR-422a) showed differential expression patterns in lung tissues before and after infection. Especially, hsa-miR-15b-5p and hsa-miR-195-5p showed a large difference in expression, indicating that they may potentially be diagnostic biomarkers for SARS-CoV-2 infection.

• Pediatric Infection and Vaccine
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• 제22권3호
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• pp.143-146
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• 2015

중동호흡기증후군 코로나바이러스(Middle East respiratory coronavirus, MERS-CoV)로 인한 질환은 2012년부터 보고되었다. 현재까지 대부분의 질환은 성인에서 발생하였으며 소아에 대한 보고는 매우 부족한 실정이다. 그리하여 본 연구에서는 소아에서 MERS-CoV 감염증의 역학적 특성과 임상 양상을 분석하였다. 전세계적으로 MERS-CoV에 감염된 소아는 34명이었으며(2015년 10월 29일 기준), 이는 전체 환자의 2.1%를 차지하였다. 소아 환자들의 중앙 연령은 13세(범위, 9개월부터 17세까지)이었으며, 성별이 보고된 자료(n=33) 중 57.6%가 남자였다. 전체 환자 중에서 약 반은 무증상 감염이었으며, 대부분의 증상이 있는 환자는 호흡기 증상을 동반하였다. MERS-CoV에 감염된 환자들의 예후는 대부분 양호하였으나, 사망한 환자는 4명이었으며 이 중 3명은 기저 질환이 있었다. 전세계적으로 소아에서 발생한 MERS-CoV 감염에 대한 보고 자료를 분석한 결과 MERS-CoV 감염은 소아에서 발생이 낮고 성인에 비해 예후가 좋은 것으로 나타났다.

• IMMUNE NETWORK
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• 제21권5호
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• pp.32.1-32.14
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• 2021

Over two hundred twenty-eight million cases of coronavirus disease 2019 (COVID-19) in the world have been reported until the 21^st of September 2021 after the first rise in December 2019. The virus caused the disease called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 4 million deaths blame COVID-19 during the last one year and 8 months in the world. Currently, four SARS-CoV-2 variants of concern are mainly focused by pandemic studies with limited experiments to translate the infectivity and pathogenicity of each variant. The SARS-CoV-2 α, β, γ, and δ variant of concern was originated from United Kingdom, South Africa, Brazil/Japan, and India, respectively. The classification of SARS-CoV-2 variant is based on the mutation in spike (S) gene on the envelop of SARS-CoV-2. This review describes four SARS-CoV-2 α, β, γ, and δ variants of concern including SARS-CoV-2 ε, ζ, η, ι, κ, and B.1.617.3 variants of interest and alert. Recently, SARS-CoV-2 δ variant prevails over different countries that have 3 unique mutation sites: E156del/R158G in the N-terminal domain and T478K in a crucial receptor binding domain. A particular mutation in the functional domain of the S gene is probably associated with the infectivity and pathogenesis of the SARS-CoV-2 variant.

• Pediatric Infection and Vaccine
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• 제27권1호
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• pp.1-10
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• 2020

2019년 12월에 중국 후베이성 우한시에서 원인 미상 폐렴이 무리 지어 발생하기 시작하였다. 환자의 하기도에서 이전에 알려지지 않은 새로운 코로나바이러스가 분리되었으며 severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)로 명명되었다. 세계보건기구는 SARS-CoV-2에 의한 질병을 코로나바이러스감염증-19(coronavirus disease 2019, COVID-19)로 명명하였다. 2020년 3월 11일에 COVID-19는 전세계 최소 114국으로 퍼졌으며 약 4,000명이 사망하여 세계보건기구는 COVID-19가 세계적 대유행임을 선언하였다. 지난 20년 동안 새로운 코로나바이러스에 의한 두 번의 유행이 있었다. 2002-2003년 중증급성호흡기증후군(severe acute respiratory syndrome, SARS) 유행 시에는 8,098명의 확진 환자와 774명의 사망자가 발생하였으며, 2012년에 사우디 아라비아에서 시작되어 현재까지 주로 아라비아 반도에서 발생하고 있는 중동호흡기증후군(Middle East respiratory syndrome, MERS)는 2019년까지 총 2,499명의 환자와 858명의 사망자를 발생시켰다. 본 종설의 목적은 2020년 3월 12일까지 알려진 SARS-CoV-2의 특징과 전파 양상 및 COVID-19의 임상 증상을 알아보고 SARS와 MERS와의 유사점 및 차이점에 대하여 간략하게 소개하는 것이다.