Previous studies have shown that proline mutations in the heptad repeat region stabilize the coronavirus spike (S) protein in a pre-fusion state. To understand the impact of proline substitutions on the fusogenicity of the S protein, we engineered the swine acute diarrhea syndrome coronavirus (SADS-CoV) S protein with two proline substitutions (S-PP) and examined its fusogenicity using dual-split-protein based cell-cell fusion assay. Unlike the wild-type S (S-WT), S-PP rarely formed syncytia. Additionally, protein expression of S-PP was impaired compared to S-WT, as previously reported. Our results indicate that pre-fusion stabilized S protein is unable to induce membrane fusion and provide a better understanding of SADS-CoV S and vaccine antigen design.

Purpose: As the coronavirus disease 2019 (COVID-19) emerged as a global crisis in 2020, nursing students experienced an abrupt transition from offline to online classes. An in-depth understanding of the online learning experiences of nursing students can be used to reorganize nursing education during the pandemic. Therefore, this study explored the online learning experiences of nursing students during the COVID-19 pandemic. Methods: A descriptive qualitative design was employed. This study used purposive sampling to recruit 20 nursing students from a nursing college. Data were collected between November 2021 and March 2022 using semi-structured focus groups or one-to-one in-depth interviews. The collected data were analyzed using inductive content analysis. Results: Five main categories emerged from the analysis: (a) ambivalence toward rapidly changing learning methods, (b) becoming familiar with online learning, (c) facing the limitations of online learning environment, (d) discovering the charm of online learning, and (e) making suggestions for future online learning. Conclusion: Nursing students experienced disappointments and concerns about online learning classes in rapidly changing situations but also experienced an efficient aspect. Psychological support and the latest information should be provided to nursing students who may experience psychological distress during this pandemic. Additionally, learning strategies and methods should be reorganized to reflect the characteristics of nursing courses and the preferences of nursing students.

Purpose: This study aimed to explore advanced response policies and psychological and emotional support measures for early infected people in the event of an infectious disease by analyzing the experiences of self-employed women who experienced confirmation in the early stages of the coronavirus disease 2019(COVID-19) pandemic. Methods: Data were collected through in-depth interviews with six experiences of self-employed women confirmed with COVID-19 in the early stages of the pandemic selected through the intentional sampling process, and then analyzed and interpreted through Interpretative Phenomenological Analysis (IPA). Results: Through analyzing the meaningful statement of the study participants, several themes were identified, including “The pressure of dying from an incurable illness”, “The fear of quarantine and the fear of death”, “The difficulty of being a self-employed woman”, “The pain of social stigma”, “The driving force of one’s overcoming”, and “Expansion of perspective due to new experiences”. Conclusion: The study found that participants experienced anxiety and fear during the transfer process and admission to the facility after confirmation, due to the lack of guidance and face-to-face interactions. The non-face-to-face treatment increased their anxiety, as they could not receive accurate information about their health conditions and care. This highlights the impact of inaccurate information regarding COVID-19 and media reports focusing on severely ill patients and deaths. In addition, the study participants experienced social stigma caused by COVID-19, resulting in changes in their interpersonal relationships and life attitudes. Implications are suggested based on the results of this study.

Purpose: This study explored life experiences and meaning attributed to them by older men living alone during the pandemic of coronavirus disease 2019 (COVID-19). Methods: Data were collected from June to July 2022 through face-to-face in-depth interviews with 14 older men living alone and analyzed using the thematic analysis method suggested by Braun and Clarke. Results: The analysis revealed four themes and eight subthemes. 1) Unfamiliar daily life faced in old age due to COVID-19; 2) living a difficult life in a stopped society; 3) a life of constant effort amid change; and 4) daily life adjusting to the new normal amid regret. The participants volunteered to be secluded to adapt to their changed daily life in an isolated society, which led to depression. As time passed, they tried to adapt to their new daily lives by communicating untactfully to shorten their physical distance. Conclusion: This study suggests that it is necessary to understand socially vulnerable classes in national disaster situations and the need for various policies to respond to social isolation. In the future, developing an intervention that allows older men living alone to actively adapt to a changing society and verify its effectiveness is necessary.

Despite the massive impact of COVID-19 on society, beyond the numbers of confirmed cases and deaths, there remains a lack of large-scale data depicting the effects of the virus on the society of the Republic of Korea. To fill this gap, we collected 1.822 million news articles with more than 1 billion morphemes from January 2020 to June 2022, creating a Korean version of the Coronavirus Corpus. This corpus is introduced in the current study. In addition, to demonstrate how such massive corpus can be utilized, we conducted information theoretical analyses to see how the stance of the press media on topics such as vaccines and social distancing affected the COVID-19 situation in the Republic of Korea. Specifically, we utilized several computational linguistic skills including concordance building and sentiment analysis through both traditional and machine learning techniques and measured the transfer entropy to estimate the impact with information theory. The results suggest that the overall impact of the press media on the society was minimal to non-existent.

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory disease in humans, with a case fatality rate of approximately 35%, thus posing a considerable threat to public health. A lack of approved vaccines or antivirals currently constitutes a barrier for controlling disease outbreaks and spread. In this study, we generated a replication-defective recombinant vesicular stomatitis virus expressing the MERS-CoV spike (S) protein (VSV/MERS). Uncleaved and cleaved S proteins were detected in VSV/MERS by western blotting. And VSV/MERS specifically transduced cells expressing human dipeptidyl peptidase 4, a receptor for MERS-CoV. To investigate the immunogenicity of VSV/MERS, mice were immunized intramuscularly with VSV/MERS and alum adjuvant. MERS-CoV S-specific IgG was detected in serum samples from immunized mice. These antibodies inhibited MERS entry in vitro, suggesting a protective efficacy of VSV/MERS immunity. The data demonstrate that VSV/MERS has potent immunogenicity and could serve as a novel potential vaccine platform for MERS in dromedary camels and human.

This short article examines whether China has incurred responsibility for violating a general due diligence obligation in customary international law or specific obligations under the WHO’s International Health Regulations and the WHO Constitution in a context of Covid-19. It is submitted that due diligence is merely a notion to describe a primary obligation, or a standard by which a particular primary obligation is assessed. It cannot serve as the basis for holding a State responsible. Regarding the WHO regime, actions taken by China after December 2019 neatly fit into the staggered requirements of Articles 6 and 7 of the International Health Regulations, which do not set out clear standards for the evaluation of a health emergency. On a more general level, we reflect upon the role of international law in global pandemic control and caution against the politicization of international health law.

Since a cluster of pneumonia cases of unknown etiology was first reported in China in December 2019, the number of confirmed cases with coronavirus disease 2019 (COVID-19) (caused by severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) worldwide has been increasing, and nearly two million patients are expected to have died by February 2021. Globally, COVID-19 is being considered a primary pulmonary disease, but it is more than a lung infection. This is because patients infected with SARS-CoV-2 present with a variety of clinical signs and symptoms involving many organs, ranging from fever, inflammation, myocardial injury, shock, and the development of coronary artery aneurysm. SARS-CoV-2 shows unique characteristics in its transmission, mortality, and stability in different environmental conditions. During COVID-19 pandemic, about 10 drugs have been clinically tried with none proven to be effective. With no prospect for effective drugs in the near future, there are currently possibilities of success with vaccines and convalescent plasma. Along with the prospect of vaccines and other therapeutic drugs, special precautions (isolation, testing, treating, and tracing) are strictly recommended until we return to normal situations. In this review we comprehensively analyzed the clinical presentations, characteristics, and outcomes of patients with COVID-19, and tried to assess the clinical effects of some drugs as part of the ongoing efforts to understand COVID-19 pandemic.

Porcine epidemic diarrhea virus (PEDV) is a porcine coronavirus that causes enteric diseases characterized by watery diarrhea and dehydration in suckling piglets. Concentrated and highly purified viruses are required for the preparation of vaccines, diagnostics, and virus research. Currently, most protocols for virus purification require ultracentrifugation, which can be an instrumental barrier to routine operations in a laboratory. In this study, the efficacy of low-speed centrifugation for virus concentration was examined. The SM98 strain of PEDV was propagated in Vero cells and pelleted by centrifugation for 3 h at high speed (100,000 × g) or for 18 h at low speed (10,000 × g). The efficacy of virus concentration was analyzed by virus titration and western blotting. The amounts of infectious viruses and viral proteins in the pelleted samples obtained by low-speed centrifugation were comparable to those obtained by high-speed centrifugation. Interestingly, the pelleted sample impurity level was lower in low-speed than in high-speed centrifugation. In summary, we describe an efficient, easy-to-perform protocol for the preparation of purified and concentrated PEDV.

Canine respiratory coronavirus (CRCoV) is commonly associated with canine kennel cough worldwide. Clinically infected dogs present coughing, sneezing, and nasal discharge. Severe infections may progress to pneumonia. Through serological surveys, CRCoV has been identified as a worldwide pathogen found in the respiratory tracts of dogs suffering from mild or severe respiratory disease. In this study, three dogs were obtained from a dog kennel. Over the previous 5 days, the dogs showed coughing, sneezing, and nasal discharge. To detect the etiologic pathogen, we performed multiplex RT-PCR (mRT-PCR) to amplify the genes encoding canine influenza virus matrix protein, canine distemper virus nucleocapsid protein, and CRCoV spike protein. Dot blotting was achieved with a CRCoV-specific probe. Nasal-secreting CRCoV was detected by the 442 bp CRCoV-positive PCR reaction in the nasal swabbing samples from dogs. Further, CRCoV-positive reactions by dot blot hybridization were detected in the nasal swabbing samples from dogs. In conclusion, we detected CRCoV in kenneled dogs with respiratory disease in Korea. Multiplex RT-PCR was able to detect successfully CRCoV infection in dogs. We suggest that mRT-PCR would be useful and effective for monitoring CRCoV infection in various kinds of dogs.

This paper examines the effect of COVID-19 pandemic on the Philippine stock exchange, peso-dollar rate and retail price of diesel using robust least squares regression and vector autoregression (VAR). The robust least squares regression using MM-estimation method concluded that COVID-19 daily infection has negative and statistically significant effect on the Philippine stock exchange index, pesodollar exchange rate and retail pump price of diesel. This is consistent with the results of correlation diagnostics. As for the VAR model, the lag values of the independent variable disclose significance in explaining the Philippine stock exchange index, peso-dollar exchange rate and retail pump price of diesel. Moreover, in the short run, the impulse response function confirmed relative effect of COVID-19 daily infections and the variance decomposition divulge that COVID-19 daily infections have accounted for only minor portion in explaining fluctuations of the Philippine stock exchange index, peso-dollar exchange and retail pump price of diesel. In the long term, the influence levels off. The Granger causality test suggests that COVID-19 daily infections cause changes in the Philippine stock exchange index and peso-dollar exchange rate in the short run. However, COVID-19 infection has no causal link with retail pump price of diesel.

The outbreak of a recent strain of Coronavirus, known as ‘COVID-19’, has spread sharply from China across the globe, resulting in a dramatic recession in the global economy. This uncertainty has therefore negatively influenced the business perspective and the various formulated strategies that may not considered such [extreme] circumstances. Using baseline analysis and archival data, this paper reports some of the major implications of COVID-19 on global business and strategy and puts forward suggested research agenda as potential future directions for organizations. In order to survive and remain sustainable, this paper argues that businesses need to revisit their strategies during current COVID-19 crises from three perspectives, including supporting human resources financial commitment, forming crossfunctional teams and connecting with their supply chains, as well as investing in corporate social responsibility and doubling down efforts with regard to partnerships. The study also represents a preliminary analysis to the implications of COVID-19 on the business and strategies across the globe and is considered the first such in the field of business, as to date all research papers on COVID-19 have been published in medical-related journals. Directions for future research are also proposed at the end of this study.

코로나 바이러스의 영향으로 2020년에 중국은 장시간 동안 '자택 격리' 상태에 있었고 매장이 문을 닫고 식당과 오락장소가 영업을 중단했다. 쇼핑센터, 극장, 관광, 음식 등 오프라인 소비에 큰 충격을 주 었다. 조사연구에 따르면 코로나바이러스가 발생한 후 85%의 식음료업계는 고객수량이 동기 대비 80% 이상 떨어졌고 그 중에서 60%가 영업을 중단했다고 밝혔다. 이 갑작스러운 코로나 바이러스로 인해 전 국민의 생산이나 생활방식이 신속하게 바뀌었고 전통적인 매장의 판매 모델은 곤경에 빠졌다. 전통적인 소매업계는 어려움을 겪으면서 영업 수입이 급감하는 심각한 도전에 직면했을 뿐만 아니라 임금복지, 영업세, 임대료 등 고정비용 부담까지 겹쳐 있다. 그러나 시장 경제가 정체된 것처럼 보이는 상황에서 신흥 판매 모델은 점점 인기를 끌고 시장과 각 분야의 인정을 받고 있다. '밖에 나가지 않는 상태는 사람들의 소비 행위를 완전히 제한하지 않는 것 같다. 5G 인터넷 기술에 의해 빠르고 효율적이며 거의 미친 듯 한 온라인 생방송 판매 모델은 오프라인 매장과 온라인에서 병행하는 새로운 판매 모델을 신속 하게 추진했다. 그렇기 때문에 소매상들은 구조 전환의 속도를 빠르게 하고 위기에서 생존을 추구하며 뜨거운 '온라인 생방송' 모델은 판매를 추진하고 소비를 추진하는 큰 기대를 가진다. 이런 상황에서 많 은 업체들도 '캐스터' 로 변신하여 판로를 확대한다. 코로나 바이러스심각하기 때문에 중국 소매업도 빠르게 온라인 생방송 마케팅 시대에 접어들었다.

The Coronavirus disease (COVID-19), first identified in China in December 2019, has widely spread worldwide and is an ongoing pandemic. It is expected that the ripple effect of COVID-19 on the global economy including the agricultural sector will increase substantially if not properly controlled shortly. This study examines the potential impact of COVID-19 on the Korean beef cattle sector and farm labor demand for Korean beef cattle using a dynamic partial equilibrium model. The agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming pessimistic GDP growth rate (-1.2% in 2020) with no direct supply shocks fell by up to 4.00% and 0.67%, respectively, compared to the baseline which represents the future without COVID-19 outbreak. On the other hand, the agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming both pessimistic GDP growth rate and supply shocks (-12.7% beef imports and + 2.4% feed cost in 2020) increased by up to 12.08% and 1.99%, respectively, compared to the baseline.