COVID-19 spreading prediction model based on a multi-head self-attention mechanism (preprint)

Background The COVID-19 pandemic is one of the most severe global health epidemics in recent decades. Its consequences have affected hundreds of millions of people in countries around the world because of the high contagiousness and mortality rate.Results To further improve the prediction accuracy of the long-term spreading trend of COVID-19, this paper proposes a hybrid neural network prediction model based on a bidirectional long short-term memory network (Bi-LSTM) combined with a multi-head self-attention mechanism. To achieve long-term prediction, this model combines multiple linear regression with the improved susceptible-exposed-infected-recovered (SEIR) model. The bidirectional long short-term memory network can mine important features of input data in both forward and backward directions, and the multi-head self-attention mechanism can capture different attention information to improve the expression ability of the model and help improve the prediction performance. The comparative analysis and prediction of multiple models are based on official real data.Conclusion The experimental results show that compared with the long short-term memory network (LSTM) and single chamber model, the proposed COVID-19 spreading model can achieve higher prediction accuracy.

Analysis of related factors of head and face pressure injury caused by protective equipment in medical staffs of epidemic prevention hospitals in Huangshi

Objective: To investigate the reasons for head face pressure injury caused by protective equipment during the prevention and control of COVID-19.

Enhancement of nanoparticle formation and growth during the COVID-19 lockdown period in urban Beijing

Influenced by the spread of the global 2019 novel coronavirus (COVID-19) pandemic, primary emissions of particles and precursors associated with anthropogenic activities decreased significantly in China during the Chinese New Year of 2020 and the lockdown period (24 January–16 February 2020). The 2-month measurements of the number size distribution of neutral particles and charged ions showed that during the lockdown (LCD) period, the number concentration of particles smaller than 100 nm decreased by approximately 40 % compared to the pre-LCD period in January. However, the accumulation mode particles increased by approximately 20 % as several polluted episodes contributed to secondary aerosol formation. In this study, new particle formation (NPF) events were found to be enhanced in the nucleation and growth processes during the LCD period, as indicated by the higher formation rate of 2 nm particles (J2) and the subsequent growth rate (GR). The relevant precursors, e.g., SO2 and NO2, showed a clear reduction, and O3 increased by 80 % during LCD period, as compared with pre-LCD. The volatile organic vapors showed different trends due to their sources. The proxy sulfuric acid during the LCD period increased by approximately 26 %, as compared with pre-LCD. The major oxidants (O3, OH, and NO3) of VOCs were also found to be elevated during LCD. That indicated higherJ2 and GR (especially below 5 nm) during the LCD period were favored by the increased concentration level of condensing vapors and decreased condensation sink. Several heavy haze episodes have been reported by other studies during the LCD period;however, the increase in nanoparticle number concentration should also be considered. Some typical NPF events produced a high number concentration of nanoparticles that intensified in the following days to create severe aerosol pollution under unfavorable meteorological conditions. Our study confirms a significant enhancement of the nucleation and growth process of nanoparticles during the COVID-19 LCD in Beijing and highlights the necessity of controlling nanoparticles in current and future air quality management.

Altered O-glycosylation Level of SARS-CoV-2 Spike Protein by Host O-glycosyltransferase Strengthens Its Trimeric Structure (preprint)

The trimeric spike protein (S) mediates host-cell entry and membrane fusion of SARS-CoV-2. S protein is highly glycosylated, whereas its O-glycosylation is still poorly understood. Herein, we site-specifically examine the O-glycosylation of S protein through a mass spectrometric approach with HCD-triggered-ETD model. We identify 15 high-confidence O-glycosites and at least 10 distinct O-glycan structures on S protein. Peptide microarray assays prove that human ppGalNAc-T6 actively participates in O-glycosylation of S protein. Importantly, the upregulation of ppGalNAc-T6 expression can profoundly enhance the O-glycosylation level by generating new O-glycosites and increasing both O-glycan heterogeneity and intensities. Further molecular dynamics simulations reveal that the O-glycosylation on the protomer-interface regions, which are mainly modified by ppGalNAc-T6, can potentially stabilize the trimeric S protein structure. Our work provides deep molecular insights of how viral infection harnesses the host O-glycosyltransferases to dynamically regulate the O-glycosylation level of the viral envelope protein responsible for membrane fusion.

Willingness of Medical Undergraduates to Work as Volunteers for anti-epidemic of COVID-19: Reflections on Medical Education in the post-epidemic era of China (preprint)

Objective: To identify the willingness of medical undergraduates to work as volunteers for fighting COVID-19 and effect factors of willingness to volunteer. Methods: A cross-sectional online questionnaire survey which consisted of three sections with 26 items was conducted. The primary outcome was the willingness to volunteer. Descriptive analysis was used for the results of characteristics, a univariant analysis was performed by chi-square test and a multivariate analysis was performed by multivariate logistic regression. Results: A total of 5499 questionnaires were issued and 5379 effective questionnaires were finally recovered. There were 1797 males (33.4%) and 3582 females (66.6%), with an average age of 20±1.5 years old. 3553(66.1%) students wanted to volunteer. Male was associated with less adjusted OR (0.68, 0.56 to 0.81) for willingness. The undergraduates in school of public health was most (3.81, 2.26 to 6.40) willing to work. The undergraduates who had often participated in voluntary activities but not regularly was 3.23(2.03-5.16) times more willing than those that never participate. Conclusion: It suggested that medical educators should emphasize voluntary activities in undergraduate medical education and continue to insistence of medical humanities and public health education to improve the social responsibility and professional identity of medical undergraduates.