• Korean Journal of Radiology
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• v.21 no.5
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• pp.545-549
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• 2020

The 2019 novel coronavirus (2019-nCoV) outbreak in Wuhan, Hubei Province, China in 2019 led to large numbers of people being infected and developing atypical pneumonia (coronavirus disease 2019, COVID-19). Typical imaging manifestations of patients infected with 2019-nCoV has been reported, but we encountered an atypical radiological manifestation on baseline computed tomography (CT) images in three patients from Wuhan, China infected with the 2019-nCoV. Surprisingly, the only similar CT finding was a solitary sub-centimeter ground-glass nodule adjacent to bronchovascular bundles, which could be easily overlooked. In addition, the follow-up images in these patients showed how COVID-19 pneumonia evolved from these small nodules. The radiologic manifestation of the three cases will expand contemporary understanding of COVID-19.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.297-309
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• 2020

Coronaviruses were originally discovered as enzootic infections that limited to their natural animal hosts, but some strains have since crossed the animal-human species barrier and progressed to establish zoonotic diseases. Accordingly, cross-species barrier jumps resulted in the appearance of SARS-CoV, MERS-CoV, and SARS-CoV-2 that manifest as virulent human viruses. Coronaviruses contain four main structural proteins: spike, membrane, envelope, and nucleocapsid protein. The replication cycle is as follows: cell entry, genome translation, replication, assembly, and release. They were not considered highly pathogenic to humans until the outbreaks of SARS-CoV in 2002 in Guangdong province, China. The consequent outbreak of SARS in 2002 led to an epidemic with 8,422 cases, and a reported worldwide mortality rate of 11%. MERS-CoVs is highly related to camel CoVs. In 2019, a cluster of patients infected with 2019-nCoV was identified in an outbreak in Wuhan, China, and soon spread worldwide. 2019-nCoV is transmitted through the respiratory tract and then induced pneumonia. Molecular diagnosis based on upper respiratory region swabs is used for confirmation of this virus. This review examines the structure and genomic makeup of the viruses as well as the life cycle, diagnosis, and potential therapy.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.252-266
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• 2020

The coronavirus disease 2019 (COVID-19) is a highly contagious pneumonia that has spread throughout the world. It is caused by a novel, single stranded RNA virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Genetic analysis revealed that, phylogenetically, the SARS-CoV-2 is related to severe acute respiratory syndrome-like viruses seen in bats. Because of this, bats are considered as a possible primary reservoir. The World Health Organization has declared the COVID-19 outbreak as a pandemic. As of May 27, 2020, more than 5,406,282 confirmed cases, and 343,562 confirmed deaths have been reported worldwide. Currently, there are no approved vaccines or antiviral drugs available against COVID-19. Newly developed vaccines are in the first stage of clinical trials, and it may take a few months to a few years for their commercialization. At present, remdesivir and chloroquine are the promising drugs for treating COVID-19 patients. In this review, we summarize the diversity, genetic variations, primary reservoirs, epidemiology, clinical manifestations, pathogenesis, diagnosis, treatment strategies, and future prospects with respect to controlling the spread of COVID-19.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.39.1-39.18
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• 2021

The high virulent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that emerged in China at the end of 2019 has generated novel coronavirus disease, coronavirus disease 2019 (COVID-19), causing a pandemic worldwide. Every country has made great efforts to struggle against SARS-CoV-2 infection, including massive vaccination, immunological patients' surveillance, and the utilization of convalescence plasma for COVID-19 therapy. These efforts are associated with the attempts to increase the titers of SARS-CoV-2 neutralizing Abs (nAbs) generated either after infection or vaccination that represent the body's immune status. As there is no standard therapy for COVID-19 yet, virus eradication will mainly depend on these nAbs contents in the body. Therefore, serological nAbs neutralization assays become a requirement for researchers and clinicians to measure nAbs titers. Different platforms have been developed to evaluate nAbs titers utilizing various epitopes sources, including neutralization assays based on the live virus, pseudovirus, and neutralization assays utilizing recombinant SARS-CoV-2 S glycoprotein receptor binding site, receptor-binding domain. As a standard neutralization assay, the plaque reduction neutralization test (PRNT) requires isolation and propagation of live pathogenic SARS-CoV-2 virus conducted in a BSL-3 containment. Hence, other surrogate neutralization assays relevant to the PRNT play important alternatives that offer better safety besides facilitating high throughput analyses. This review discusses the current neutralization assay platforms used to evaluate nAbs, their techniques, advantages, and limitations.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.12.1-12.9
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• 2020

Coronavirus is an enveloped virus with positive-sense single-stranded RNA. Coronavirus infection in humans mainly affects the upper respiratory tract and to a lesser extent the gastrointestinal tract. Clinical symptoms of coronavirus infections can range from relatively mild (similar to the common cold) to severe (bronchitis, pneumonia, and renal involvement). The disease caused by the 2019 novel coronavirus (2019-nCoV) was called Covid-19 by the World Health Organization in February 2020. Face-to-face communication and consistent exposure to body fluids such as blood and saliva predispose dental care workers at serious risk for 2019-nCoV infection. As demonstrated by the recent coronavirus outbreak, information is not enough. During dental practice, blood and saliva can be scattered. Accordingly, dental practice can be a potential risk for dental staff, and there is a high risk of cross-infection. This article addresses all information collected to date on the virus, in accordance with the guidelines of international health care institutions, and provides a comprehensive protocol for managing possible exposure to patients or those suspected of having coronavirus.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.501-504
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• 2020

From December 2019, Coronavirus disease 2019 (COVID-19) pneumonia (formerly known as the 2019 novel Coronavirus [2019-nCoV]) broke out in Wuhan, China. In this study, we present serial CT findings in a 40-year-old female patient with COVID-19 pneumonia who presented with the symptoms of fever, chest tightness, and fatigue. She was diagnosed with COVID-19 infection confirmed by real-time reverse-transcriptase-polymerase chain reaction. CT showed rapidly progressing peripheral consolidations and ground-glass opacities in both lungs. After treatment, the lesions were shown to be almost absorbed leaving the fibrous lesions.

• IMMUNE NETWORK
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• v.21 no.5
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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.

• Current Optics and Photonics
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• v.3 no.6
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• pp.516-521
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• 2019

The electrical leakage levels of GaN-based light-emitting diodes (LEDs) containing leakage paths are estimated using photoluminescence (PL) and photovoltaic properties under photoexcitation conditions. The PL intensity and open-circuit voltage (V_OC) decrease because of carrier leakages depending on photoexcitation conditions when compared with reference values for typical LED chips without leakage paths. Changes of photovoltage-photocurrent characteristics and PL intensity due to carrier leakage are employed to assess the leakage current levels of LEDs with leakage paths. The current corresponding to the reduced V_OC of an LED with leakage from the photovoltaic curve of a reference LED without leakage is matched with the leakage current calculated using the PL intensity reduction ratio and short-circuit current of the LED with leakage. The current needed to increase the voltage for an LED with a leakage under photoexcitation from V_OC of the LED up to V_OC of a reference LED without a leakage is identical to the additional current needed for optical turn-on of the LED with a leakage. The leakage current level estimated using the PL and photovoltaic properties under photoexcitation is consistent with the leakage level measured from the voltage-current characteristic obtained under current injection conditions.

• Genomics & Informatics
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• v.18 no.4
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• pp.43.1-43.13
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• 2020

The coronavirus disease 2019 is a contagious disease and had caused havoc throughout the world by creating widespread mortality and morbidity. The unavailability of vaccines and proper antiviral drugs encourages the researchers to identify potential antiviral drugs to be used against the virus. The presence of RNA binding domain in the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be a potential drug target, which serves multiple critical functions during the viral life cycle, especially the viral replication. Since vaccine development might take some time, the identification of a drug compound targeting viral replication might offer a solution for treatment. The study analyzed the phylogenetic relationship of N protein sequence divergence with other 49 coronavirus species and also identified the conserved regions according to protein families through conserved domain search. Good structural binding affinities of a few natural and/or synthetic phytocompounds or drugs against N protein were determined using the molecular docking approaches. The analyzed compounds presented the higher numbers of hydrogen bonds of selected chemicals supporting the drug-ability of these compounds. Among them, the established antiviral drug glycyrrhizic acid and the phytochemical theaflavin can be considered as possible drug compounds against target N protein of SARS-CoV-2 as they showed lower binding affinities. The findings of this study might lead to the development of a drug for the SARS-CoV-2 mediated disease and offer solution to treatment of SARS-CoV-2 infection.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.791-796
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• 2020

Nuclear fusion seems to be a good choice of energy source in the future. Nickel is one of the crucial structural materials for fusion devices. In this work, the cross section data of ⁵⁸Ni(n,p)⁵⁸Co, ⁶⁰Ni(n,p)⁶⁰Co, ⁶¹Ni(n,p)⁶¹Co, ⁶²Ni(n,p)⁶²Co and ⁶⁴Ni(n,p)⁶⁴Co reactions were calculated using the nuclear codes ALICE/ASH, EMPIRE 3.2 and TALYS 1.8. In addition, the cross sections were calculated with the empirical formulas obtained in our previous paper at 14-15 MeV. The obtained results were compared with the measured values in the literature, and with the evaluated data files (JEFF-3.3, TENDL-2017, ENDF/B-VIII.0).