ABSTRACT
Background Due to the global outbreak of the COVID-19 epidemic, schools were forced to shift teaching from face-face to online. During this period, a large number of studies on how to better carry out online teaching emerged. However, these studies were basically conducted with domestic students as teaching objects. The research on transnational online education conducted by overseas students is very limited.This case study aims to share the author's research and practical experience on transnational online teaching after the outbreak of the pandemic, and how to choose the appropriate teaching platform to ensure the quality of online teaching. I hope it can give some inspiration to others, and provide a reliable methodology for transnational online teaching.Methods We first conducted a questionnaire survey on the obstacles of transnational online learning of 64 international students from our school who were staying abroad. Then, we analyzed the reasons for these obstacles and timely changed the teaching platform and compared the results of the biochemistry exam conducted for 2018 spring class with those of 2018 fall class and the 2019 fall class, so as to verify the superiority of the DingTalk as a transnational online education platform.Results The results of the questionnaire showed that the main difficulties of overseas students in transnational online learning are poor network conditions and time difference. Because the teaching platform was separated from the interactive Q&A platform, resulting in poor interaction between teachers and students. By using DingTalk as an online teaching platform, the previous difficulties were overcome. In the spring class of 2018, the results of online study students' biochemistry were significantly lower than those of students in face-face study(t-test, p = 0.01). However, after the switch to the DingTalk platform, online students’ results in the 2018 fall Class(t-test, p = 0.35) and the 2019 fall-Class(t-test, p = 0.7) were equivalent to the academic performance of face-face students.Conclusion Through our exploration and application of Dingtalk software in transnational online education, we successfully solved the dilemma of overseas students' online learning, and also provided a feasible method for us to guarantee the efficacy of online teaching.
Subject(s)
COVID-19ABSTRACT
Background: Based on the current status of the COVID-19 global pandemic, there is an urgent need to systematically evaluate the effectiveness of wearing masks to protect public health from COVID-19 infection. Methods: We conducted a systematic review and meta-analysis to evaluate the effectiveness of using face masks to prevent the spread of SARS-CoV-2. Relevant articles were retrieved from PubMed, Web of Science, ScienceDirect, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI), VIP (Chinese) database. There were no language restrictions. This study was registered with PROSPERO under the number CRD42020211862. Results: A total of 6 case-control studies were included. In general, wearing a mask was associated with a significantly reduced risk of COVID-19 infection (OR = 0.38, 95% CI = 0.21-0.69, I2 = 54.1%). Heterogeneity modifiers were investigated by subgroup analysis. For healthcare workers group, masks were shown to have a reduce risk of infection by nearly 70%. Studies in China showed a higher protective effect than other countries. Adjusted estimates and subgroup analyses showed similar findings. Conclusions: The results of this systematic review and meta-analysis support the conclusion that wearing a mask could reduce the risk of COVID-19 infection.
Subject(s)
COVID-19ABSTRACT
Today, we are all threatened by an unprecedented pandemic: COVID-19. How different is it from other coronaviruses? Will it be attenuated or become more virulent? Which animals may be its original host? In this study, we collected and analyzed nearly thirty thousand publicly available complete genome sequences for COVID-19 virus from 79 different countries, the previously known flu-causing coronaviruses (HCov-229E, HCov-OC43, HCov-NL63 and HCov-HKU1) and the lethal, pathogenic viruses, SARS, MERS, Victoria, Lassa, Yamagata, Ebola, and Dengue. We found strong similarities between the current circulating COVID-19 and SARS and MERS, as well as COVID-19 in rhinolophines and pangolins. On the contrary, COVID-19 shares little similarity with the flu-causing coronaviruses and the other known viruses. Strikingly, we observed that the divergence of COVID-19 strains isolated from human hosts has steadily increased from December 2019 to May 2020, suggesting COVID-19 is actively evolving in human hosts. In this paper, we first propose a novel MLCS algorithm NP-MLCS1 for the big sequence analysis, which can calculate the common model for COVID-19 complete genome sequences to provide important information for vaccine and antibody development. Geographic and time-course analysis of the evolution trees of the human COVID-19 reveals possible evolutional paths among strains from 79 countries. This finding has important implications to the management of COVID-19 and the development of vaccines and medications.