ABSTRACT
The COVID-19 epidemic has disrupted the normal teaching and learning in universities, which poses significant challenges to higher education. The traditional face-to-face learning mode has been switched to online (distance) learning, causing various influences on students' academic performance, physical and psychological well-being. As higher education plays a central role in technology innovation and society development, it is of great importance to investigate and improve online learning in the context of COVID-19. This study distributed online questionnaires to undergraduate and postgraduate students from 30 provinces or municipalities in China (covering 88% of the whole country). Results indicate that online learning mode is more likely to reduce the academic performance of lower-grade students (e.g., freshman and sophomore). The learning environment could be one of essential factors affecting the academic performance during online education. Studying at home or dormitory is more evidently correlated with academic performance decline. Regarding the physical and mental health during online learning, most students had experienced eye strain (84%) and cervical stiff (79%), while anxiety is the most prominent mental issue (66% of occurrence). Several coping strategies are suggested to improve the online learning in post-pandemic era, which is essential for higher education and promoting a civilized and sustainable society.
ABSTRACT
OBJECTIVE: The aim of the study was to analyze the relationship between serum antibody and neutralizing antibody titers in convalescent coronavirus disease 2019 (COVID-19) patients with different disease severities, and the seropositive reaction rates of 9 reported B-cell epitopes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Serum IgG and total antibody titers of 165 convalescent COVID-19 patients were determined by chemiluminescence, the serum neutralization antibody titers were determined by microneutralization assay, and the S/CO values of 9 peptides were detected by indirect enzyme-linked immunosorbent assay. Correlations between the aforementioned indexes were statistically analyzed, and differences in patients with different diseases severities were evaluated. RESULTS: IgG, total antibody, and neutralizing antibody titers increased with disease severity. The positive rate of the receptor-binding region (RBD) was 100%, and the average positive rate for all the 9 peptides was above 50% in 165 patients. IDf showed the highest rate of positivity (86.06%), with a rate of 95% for the (IDf + IDa) pattern. Moreover, S/CO values of RBD and mix (IDh) were significantly correlated with IgG, total antibody titers, and neutralizing antibody titers (p < 0.001), whereas the S/CO values for other 8 peptides showed no obvious correlation. CONCLUSION: In this study, a large sample was used to confirm that the peptide IDf had a high positive reaction rate for all patients (86.06%) and also had the highest detection rate in asymptomatic patients (86.67%). Only long peptide and mixed peptide showed correlation with neutralizing antibody titers, suggesting that the ability of SARS-CoV-2 antibody to neutralize virus infectivity may require the interaction of multiple sites.