COVID-19 spike polypeptide vaccine reduces the pathogenesis and viral infection in a mouse model of SARS-CoV-2

The SARS-CoV-2 coronavirus, which causes a respiratory disease called COVID-19, has been declared a pandemic by the World Health Organization (WHO) and is still ongoing. Vaccination is the most important strategy to end the pandemic. Several vaccines have been approved, as evidenced by the ongoing global pandemic, but the pandemic is far from over and no fully effective vaccine is yet available. One of the most critical steps in vaccine development is the selection of appropriate antigens and their proper introduction into the immune system. Therefore, in this study, we developed and evaluated two proposed vaccines composed of single and multiple SARS-CoV-2 polypeptides derived from the spike protein, namely, vaccine A and vaccine B, respectively. The polypeptides were validated by the sera of COVID-19-vaccinated individuals and/or naturally infected COVID-19 patients to shortlist the starting pool of antigens followed by in vivo vaccination to hACE2 transgenic mice. The spike multiple polypeptide vaccine (vaccine B) was more potent to reduce the pathogenesis of organs, resulting in higher protection against the SARS-CoV-2 infection.

COVID-19 spike polypeptide vaccine reduces the pathogenesis and viral infection in a mouse model of SARS-CoV-2.

The SARS-CoV-2 coronavirus, which causes a respiratory disease called COVID-19, has been declared a pandemic by the World Health Organization (WHO) and is still ongoing. Vaccination is the most important strategy to end the pandemic. Several vaccines have been approved, as evidenced by the ongoing global pandemic, but the pandemic is far from over and no fully effective vaccine is yet available. One of the most critical steps in vaccine development is the selection of appropriate antigens and their proper introduction into the immune system. Therefore, in this study, we developed and evaluated two proposed vaccines composed of single and multiple SARS-CoV-2 polypeptides derived from the spike protein, namely, vaccine A and vaccine B, respectively. The polypeptides were validated by the sera of COVID-19-vaccinated individuals and/or naturally infected COVID-19 patients to shortlist the starting pool of antigens followed by in vivo vaccination to hACE2 transgenic mice. The spike multiple polypeptide vaccine (vaccine B) was more potent to reduce the pathogenesis of organs, resulting in higher protection against the SARS-CoV-2 infection.

"Home away from home” in pandemic times: how has COVID-19 changed the Airbnb market in Melbourne?

PurposeThis study aims to investigate how the COVID-19 pandemic has impacted and changed Airbnb market in the Greater Melbourne area in terms of its temporal and spatial patterns and identify possible shifts in underlying trends in travel activities. Design/methodology/approachA panel data set of Airbnb listings in Melbourne is analysed to compare temporal patterns, spatial distribution and lengths of stay of Airbnb users before and after the COVID outbreak. FindingsThis study found that the COVID disruption did not fundamentally change the temporal cycle of the Airbnb market. Month-to-month fluctuations peaked at different levels from pre-pandemic times mainly because of lockdowns and other restrictive measures. The impact of COVID-19 disruptions on neighbourhood-level Airbnb revenues is associated with distance to CBD rather than number of COVID cases. Inner city suburbs suffered major loss during the pandemic, whereas outer suburbs gained popularity due to increased domestic travel and long stays. Long stays (28 days or more, as defined by Airbnb) were the fastest growing segment during the pandemic, which indicates the Airbnb market was adapting to increasing demand for purposes like remote working or lifestyle change. After easing of COVID-related restrictions, demand for short-term accommodation quickly recovered, but supply has not shown signs of strong recovery. Spatial distribution of post-pandemic supply recovery shows a similar spatial variation. Neighbourhoods in the inner city have not shown signs of significant recovery, whereas those in the middle and outer rings are either slowly recovering or approaching their pre-COVID levels. Practical implicationsThe COVID-19 pandemic has significantly impacted short-term rental markets and in particular the Airbnb sector during the phase of its rapid development. This paper helps inform in- and post-pandemic housing policy, market opportunity and investment decision. Originality/valueTo the best of the authors' knowledge, this is one of the first attempts to empirically examine both temporal and spatial patterns of the COVID-19 impact on Airbnb market in one of the most severely impacted major cities. It is one of the first attempts to identify shifts in underlying trends in travel based on Airbnb data.

Atomically Dispersed d10 s-block Au Boosts Photocatalytic 1e- Water Oxidation for Self-Cleaning, Sanitation and Safe Drinkable Water­­ (preprint)

Providing affordable safe drinking water and universal sanitation poses a grand challenge especially after the global COVID-19 pandemic. In this work, we developed atomically dispersed Au on potassium-incorporated polymeric carbon nitride (AuKPCN) that could simultaneously boost photocatalytic generation of ·OH and H2O2 with an apparent quantum efficiency over 90% at 400–420 nm. The introduction of potassium into the poly(heptazine imide) matrix formed strong K-N bonds, preventing Au from forming strong interactions with N. Instead, Au formed a bond with C, only having weak interactions with N on KPCN, which rendered Au with an oxidation number close to 0. The results of in-situ vibrational spectroscopy, isotopic experiments, transient absorption spectroscopy and time-dependent density functional theory (TDDFT) simulations revealed that the low-valent Au could append its 6s orbital into the band diagram of AuKPCN that formed a trapping level for generating highly localized holes under photoexcitation. These highly localized holes could boost the 1e− water oxidation reaction to form highly oxidative ·OH and simultaneously unbind the hydrogen atom in H2O molecule, which greatly promoted the hydrogenation process during the 2e− oxygen reduction reaction (ORR) to produce H2O2. The photogenerated ·OH on AuKPCN led to a more than 120-fold efficiency enhancement for visible-light-response superhydrophilicity as compared to that of the commercial TiO2. The onsite fixed-bed reactor under photo-illumination achieved a remarkable 132.5 LH2O m− 2 day− 1 water disinfection rate (lg6), which is about 30 times superior than the TiO2 photocatalytic advanced oxidation process in the most ideal case (< 4 LH2O m− 2 day− 1; lg4).

The Mediating Effects of Work-Life Balance (WLB) and Ease of Using WLB Programs in the Relationship between WLB Organizational Culture and Turnover Intention.

Work-life balance (WLB) is an important concern for all workers irrespective of their age, sex, education level, family structure, or occupation. This study analyzes WLB's mediating effects and the ease of using WLB programs in the relationship between WLB organizational culture of hotels and turnover intention of its culinary staff. We conducted a survey featuring 320 culinary staff members at hotels in Incheon from 10 to 30 August 2020 and performed statistical analysis using 290 responses. We find that the company's willingness for WLB, empathetic communication with colleagues, material support of colleagues for WLB, and the ease of using WLB programs in organizational culture had a positive impact on WLB. The company's willingness for WLB, boss's consideration for WLB, empathetic communication with colleagues, and material support of colleagues for WLB in organizational culture had a negative impact on turnover intention. The ease of using WLB programs had no indirect effect on the relationship between organizational culture and turnover intention. However, WLB had an indirect effect on the relationship between the four components except for the boss's consideration for WLB and turnover intention. Hotel management should create an organizational culture that supports the WLB of culinary staff.

The Landscape of Aminoacyl-tRNA Synthetases Involved in Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes in translation by linking amino acids onto their cognate tRNAs during protein synthesis. During evolution, aaRSs develop numerous non-canonical functions that expand the roles of aaRSs in eukaryotic organisms. Although aaRSs have been implicated in viral infection, the function of aaRSs during infections with coronaviruses (CoVs) remains unclear. Here, we analyzed the data from transcriptomic and proteomic database on human cytoplasmic (cyto) and mitochondrial (mt) aaRSs across infections with three highly pathogenic human CoVs, with a particular focus on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We found an overall downregulation of aaRSs at mRNA levels, while the protein levels of some mt-aaRSs and the phosphorylation of certain aaRSs were increased in response to SARS-CoV-2 infection. Strikingly, interaction network between SARS-CoV-2 and human aaRSs displayed a strong involvement of mt-aaRSs. Further co-immunoprecipitation (co-IP) experiments confirmed the physical interaction between SARS-CoV-2 M protein and TARS2. In addition, we identified the intermediate nodes and potential pathways involved in SARS-CoV-2 infection. This study provides an unbiased, overarching perspective on the correlation between aaRSs and SARS-CoV-2. More importantly, this work identifies TARS2, HARS2, and EARS2 as potential key factors involved in COVID-19.

Estimating Interpersonal Distance and Crowd Density with a Single Edge Camera (preprint)

For public safety and physical security, currently more than a billion closed-circuit television (CCTV) cameras are deployed around the world. Proliferation of artificial intelligence (AI) and machine learning (ML) technologies has gained significant applications including crowd surveillance. The state-of-the-art distance and area estimation algorithms either need multiple cameras or a reference scale as a ground truth. It is an open question to obtain an estimation using a single camera without a scale reference. In this paper, we propose a novel solution called E-SEC, which estimates interpersonal distance between a pair of dynamic human objects, area occupied by a dynamic crowd, and density using a single edge camera. The E-SEC framework comprises edge CCTV cameras responsible for capture a crowd on video frames leveraging a customized YOLOv3 model for human detection. E-SEC contributes an interpersonal distance estimation algorithm vital for monitoring the social distancing of a crowd, and an area estimation algorithm for dynamically determining an area occupied by a crowd with changing size and position. A unified output module generates the crowd size, interpersonal distances, social distancing violations, area, and density per every frame. Experimental results validate the accuracy and efficiency of E-SEC with a range of different video datasets.

Control of infection of medical team assisting Wuhan during COVID-19 epidemic

OBJECTIVE: To explore the control of infection in living places of medical teams assisting Wuhan during COVID-19 epidemic so as to offer help and reference for members of the medical teams. METHODS: The plans and measures for control of infection in working and living places of the medical teams were formulated based on the etiological and epidemiological characteristics of SARS-CoV-2 as well as national guidelines for diagnosis, treatment, control and prevention. RESULTS: The regulations, flow charts and plans have been formulated, involving the medical teams' responsibilities in prevention and control of infection, on-duty and off-duty flow charts and daily living management of team members, active health monitoring, emergency treatment of fever patients, and cleaning and disinfection of living places. CONCLUSION: The prevention and control of infection in the living places is one of the key links to prevent the infection in the team members and the spread of the epidemic, and the medical teams must pay great attention to and rigidly put the infection control measures into practice.

Separate Fever Clinics Prevent the Spread of COVID-19 and Offload Emergency Resources: Analysis from a large tertiary hospital in China (preprint)

Objectives: COVID-19 began spreading widely in China in January 2020. Outpatient Fever Clinics (FCs), instituted during the SARS epidemic in 2003 were upgraded to provide COVID-19 screening and prevention attached to large tertiary hospitals. We sought to analyze the effect of upgraded FCs to detecting COVID-19 at our institution. Design: A population-based cross-sectional study. Participants: A total of 6,365 patients were screened in the FC. Methods: The FC of Peking Union Medical College Hospital (PUMCH) was upgraded on January 20, 2020. We performed a retrospective study of patients presenting to the FC between December 12, 2019 to February 29, 2020, covering a period of 40 days before and after upgrading the FC. All necessary data, including baseline patient information, diagnoses, follow-up conditions for critical patients, transfer information between the FC and emergency department (ED) were collected and analyzed. Results: 6,365 patients were screened in the FC, among whom 2,192 patients were screened before January 21, 2020, while 3,453 were screened afterwards. Screening results showed that upper respiratory infection was the major disease associated with fever. Compared to before the outbreak, patients transferred from the FC to ED decreased significantly [39.21% vs 15.75%, p<0.001] and tended to spend more time in the FC [55 vs 203mins, p<0.001]. For critically-ill patients waiting for a screening result, the total length of stay in the FC was 22mins before the outbreak, compared to 442mins after the outbreak (p< 0.001). The number of in-hospital deaths of critical-care patients seen first in the FC was 9 of 29 patients before the outbreak and 21 of 38 after (p<0.050). Nineteen COVID-19 cases were confirmed in the FC, but no other patients or medical care providers were cross-infected. Conclusion: The work-load of the FC increased after the COVID-19 outbreak and effectively prevented COVID-19 from spreading in the hospital as well as offload ED resources.

Sentiment Classification for Chinese Text Based on Interactive Multitask Learning

In this paper, an interactive multitask learning method for Chinese text sentiment classification is proposed. Here, the classic BiLSTM + attention + CRF model is used to obtain full use of the interaction relationship between tasks, and it simultaneously solves the two tasks of emotional dictionary expansion and sentiment classification. The proposed method divides text sentiment classification and emotional dictionary expansion into primary task and subtask, and it adopts the Enhanced Language Representation with Informative Entities (ERNIE) model as the text representation learning model for the primary task. Then, through the maximum pooling layer and the fully connected layer, the text sentiment classification task is completed. Meanwhile, the classical BiLSTM + attention + CRF model is used to extract emotional words from the text in the subtask. In addition, the multitask information interaction mechanism is used, and the prediction information on the autonomous subtask is fed back into the potential representation of the two tasks. After iterative training, the performance of the two tasks is further optimized. Micro-blogs with COVID-19 are used here as the subject to form the experimental data set. The results demonstrate the superiority of the proposed method over other approaches, and they further verify the superiority of ERNIE over BERT, RoBERTa and XLNet for the sentiment classification of Chinese text.