Under what circumstances would airborne transmission of SARS-CoV-2 occur?

To find out the circumstances under which airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) would happen, we conducted mechanistic and systematic modelling of two Coronavirus disease 2019 (COVID-19) outbreaks, i.e., Hunan 2-bus outbreak and Luk Chuen House outbreak (the horizontal cluster). Computational fluid dynamics (CFD) simulations, multi-zone airflow modelling, multi-route mechanistic modelling, and dose-response estimation were carried out selectively according to the transmission characteristics in each outbreak. Our results revealed that poorly ventilated bus indoor environments bred the Hunan 2-bus outbreak in which airborne transmission predominates;prevailing easterly background wind and probable door opening behaviour led to the secondary infections across the corridor in Luk Chuen House outbreak. Measures to facilitate sufficient ventilation indoors and positive pressure in the housing building corridor may help minimise infection risk. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

Negotiating the temporal and spatial complexities: Chinese international students' learning experience at home during the COVID-19

Many Chinese international students had to or chose to leave their host universities, receiving online international higher education (HE) at ‘homes' during the COVID-19. Inspired by the ‘glonacal' mode of thought, this qualitative study interviewed 16 Chinese international students at ‘homes' to explore the potential complexities of spatiality and temporality regarding their online international HE experiences during COVID-19. Physically separating from host universities, our participants lost the sense of belongingness to the campus and felt disconnected with their academic communities. Their stories revealed a different ‘money' value between gaining and losing regarding online international HE experiences at ‘homes', and the disadvantages they experienced at host countries/universities. Our participants experienced temporal flexibility, temporal conflicts and temporal asymmetry simultaneously. Such spatial and temporal complexities intertwined with each other, making international student experience (ISE) during the COVID-19 unique. This article contributes to understanding of ISE and internationalisation of HE for a post-pandemic era. © 2023 HERDSA.

Erratum: Multisite Inhibitors for Enteric Coronavirus: Antiviral Cationic Carbon Dots Based on Curcumin (ACS Applied Nano Materials (2018) 1:10 (5451-5459) DOI: 10.1021/acsanm.8b00779)

Page 5452. In the "2.1. Preparation of CCM-CDs" section in the Experimental Section, "Curcumin (CCM;0.30 g) and citric acid (0.60 g) were ground uniformly, sealed, and hydrothermally treated in a 25 mL Teflon-lined autoclave at 180 C for 1 h." was incorrectly written. It should be "Curcumin (CCM;0.30 g) and citric acid (0.60 g) were ground uniformly, sealed, and hydrothermally treated in a 25 mL Teflon-lined autoclave at 180 C for 1.5 h.". This change does not affect the conclusion of this paper. Page 5455. In the caption of Figure 6c, "Virus titers calculated in the presence and absence of EDA-CDs or CCMCDs. The pictures were taken at 12 hpi." was incorrectly written. It should be "Virus titers calculated in the presence and absence of EDA-CDs or CCM-CDs. The pictures were taken at 9 hpi.". In addition, the fluorescence images of the DAPI and Merge in the EDA-CDs (125 g/mL) group (Figure 6a) were chosen by mistake when the artwork was submitted. These changes do not affect the conclusion of this paper. The revised Figure 6a, which now shows the correct images from the original data source, is as follows: (Figure Present). © 2022 American Chemical Society. All rights reserved.

Problems faced in the operation of clinical trials for diseases involving fever during the regular COVID-19 prevention and control period and countermeasures.

During the regular COVID-19 prevention and control period, the running of fever-related clinical trial projects faces many problems, which will affect the development of new drugs. How to coordinate the regular COVID-19 prevention and control with the clinical trial process is the key to ensure that the clinical trial participants are successfully enrolled. In this paper, taking the influenza project as an example, combined with the practice of operation and management of the influenza clinical trial project in our hospital, the problems faced in the operation of fever-related clinical trial projects during the regular COVID-19 prevention and control period were discussed and the countermeasures and suggestions were proposed. In order to meet the dual needs of infectious disease prevention and control and clinical trials, it is recommended that in low-risk areas for COVID-19, the subject screening process be integrated with the COVID-19 exclusion process, the starting time of subject screening be moved forward, clinical trial enrollment be conducted while waiting for COVID-19 screening results, in addition, the clinical trial process after COVID-19 screening results are returned should be established in advance. Copyright © 2022, Chinese Journal of New Drugs Co. Ltd. All right reserved.

Sequential Nucleophilic Addition and Regioselective Ring-Expansion Reactions of α-Diazophosphonates with Isatins: Access to 4-Phosphonylated-3-hydroxyquinolin-2(1H)-ones

A sequential protocol of α-diazophosphonates with isatins to access a series of α-diazo-β-hydroxyphosphonate derivatives via the inorganic base catalysis was reported. The resulting α-diazo-β-hydroxyphosphonates could then be readily transformed to 4-phosphonylated-3-hydroxyquinolin-2(1H)-ones with moderate to excellent yields through a catalyst-free regioselective ring-expansion rearrangement. Control experiment demonstrates that intramolecular cyclization pathway is more reasonable for the ring-expansion process. In addition, a benzo[b]thiophene-derived isatin featured with the inhibition of SARS-CoV Mpro was also suitable for this transformation and generated the corresponding scaffolds with potential anti-virus activities for further development. © 2022 Wiley-VCH GmbH.

Studies of covid-19 outbreak control using agent-based modeling

An agent-based model was developed to study outbreaks and outbreak control for COVID-19, mainly in urban communities. Rules for people’s interactions and virus infectiousness were derived based on previous sociology studies and recently published data-driven analyses of COVID-19 epidemics. The calculated basic reproduction number of epidemics from the developed model coincided with reported values. There were three control measures considered in this paper: social distancing, self-quarantine and community quarantine. Each control measure was assessed individually at first. Later on, an artificial neural network was used to study the effects of different combinations of control measures. To help quantify the impacts of self-quarantine and community quarantine on outbreak control, both were scaled respectively. The results showed that self-quarantine was more effective than the others, but any individual control measure was ineffective in controlling outbreaks in urban communities. The results also showed that a high level of self-quarantine and general community quarantine, assisted with social distancing, would be recommended for outbreak control. © 2021, Complex Systems Publications, Inc. All rights reserved.

Research on strategy of intelligent disinfection robot based on distributed constraint optimization

In the current serious COVID-19 epidemic environment, disinfection is a laborious and extremely risky task. To improve the disinfection efficiency and reduce the disinfection risky, in this paper, the intelligent robot collaborative disinfection problem is constructed as a Distributed constrained optimization problem, in which each intelligent disinfection robot is modeled as an Agent and the constraint graph is constructed based on the actual application scenario to optimize the comprehensive benefits of energy consumption and machine wear of disinfection robots in the collaborative working process. The Proposed Distributed constrained optimization problem model is solved by the state-of-the-art algorithms DSA, MGM, Max-Sum and RM. Based on our extensive empirical evaluations, we experimentally show that the constructed Distributed constrained optimization problem model for intelligent robot collaborative disinfection can effectively plan the optimal collaborative robot patterns for identified disinfection scenarios as well as recommend the optimum parameters for each disinfection robot. © 2021 IEEE.

Factors associated with COVID-19 infection and severity in a large insured patient population in metropolitan detroit

Introduction: The novel coronavirus disease 2019 (COVID-19) pandemic is a public health emergency that disparately affects older individuals and individuals with chronic health conditions. However, the relative importance of these factors in contributing to infection-related hospitalization or death is not known. Such information could help in identify groups most in need of sheltering or early vaccination. Methods: We investigated the relationship between pre-existing medical conditions and treatments with COVID-19 diagnosis, hospitalization, intensive care unit (ICU) admission, and death. We identified 48,370 individuals aged ≥20 years with detailed longitudinal clinical and pharmaceutical records by virtue of their receiving care from a single, integrated provider serving southeast Michigan and the Detroit metropolitan area. Within this group, there were 1,196 laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections between March 12, 2020 and October 27, 2020. Logistic regression was used to assess the relationship between each of the individual characteristics, pre-existing diagnostic categories and the COVID-19 related outcomes. Results: Age (adjusted odds ratio [aOR] 1.27 per decade;P=2.03x10-6), African American and Asian race-ethnicity (aOR 3.00;P=2.53x10-9 and aOR 2.79;P=0.006, respectively vs. non-Hispanic white), body mass index (aOR 1.04 per unit increase;P=2.44x10-4), renal function (aOR 1.37 per mg/dL increase in serum creatinine;P=8.96x10-8), healthcare occupation (aOR 2.24, P=0.016), and household income (aOR 0.94 per $10,000 increase, P=0.032) were significantly associated with the combined outcome of COVID-19 related hospitalization or death. Many preexisting conditions were associated with COVID-19 hospitalization or death;however, any diabetes (aOR=1.98;P=1.76x10-6) and type-2 diabetes (aOR 1.95;P=3.52x10-6) were the most significant. Other notable associations included pain (aOR 1.71;P=1.07x10-4), history of supplemental oxygen or ventilation (aOR 7.41;P=4.07x10-4), living assistance (aOR 4.46;P=4.07x10-4), prior pulmonary embolism or DVT (aOR 2.61;P=0.001), and opioid use (aOR 3.99;P=0.002). Relationships between COVID-19 severity and both thrombosis and pain were additionally supported by analyzing pharmacy records of anticoagulant and opioid use. Conclusion: This large patient population study supports many of the risk factors previously associated with COVID-19 diagnosis and complications, including age, non-white race-ethnicity, and healthcare occupation. Higher body mass index, poorer renal function, and diabetes appear to be leading independent risk factors. The heightened risk observed for opioid users is novel and requires further investigation.

Ethical issues of clinical research on sudden infectious diseases and countermeasures

In December 2019, a new type of Corona Virus Disease 2019 (COVID-19) broke out and rapidly spreaded all over the world. Up to now, there is no proven effective antiviral treatment. In an overall climate of scientific uncertainty, social and institutional chaos, fear and mistrust, clinical research of COVID-19 face numerous challenges of ethical issues. This paper takes COVID-19 as an example to discuss the ethical problems and countermeasures of clinical research on outbreaking infectious diseases, such as the challenge to the traditional ethical review way, balancing the conflict between treating patients as a doctor under the outbreak and participating in clinical study as a researcher, informed consent of subjects, and additional study risk. It was proposed that even in an outbreak of infectious disease, we also need to follow common clinical research regulations and ethical norms, manage the problems brought by the outbreak, protect the safety of subjects, ensure the smooth conduct of clinical research, and promote the development of medical science.

[The role of time-series propagation map and activity path of confirmed cases in the analysis and determination of COVID-19 epidemic].

Objective: The time sequence transmission map and the cases travel track were used to explain the chain of transmission, describe the characteristics of transmission and analyze the mode of epidemic of novel coronavirus pneumonia, so as to provide evidence for the relevant government departments to carry out epidemic prevention and control. Methods: The time sequence transmission map and the cases travel track table were drawn, according to the time of incidence, age, sex, number of close contacts and their interrelations. Results: At the end of February 10, 2020, 63 COVID-19 cases were reported in the research area. Among them, 57 cases were confirmed (1 deaths) and 6 cases were asymptomatic, 57 cases were imported cases (90.48%), 36 cases were reported by cluster epidemic (57.14%) among friends and relatives. Cases have been spread to the fourth generation. Conclusion: The time sequence transmission map and the cases travel track showed that, in the research area, the epidemic situation of COVID-19 was mainly caused by imported case, and the clustering transmission was the major spread model. The time sequence transmission map and the cases travel track are worth popularizing in the prevention and control of major infectious diseases.

[Impact of the COVID-19 epidemic on anxiety among the elderly in community].

Objective: To compare the prevalence of anxiety among old people before and during the COVID-19 epidemic in China, and to provide scientific evidence for psychological intervention of the elderly during public health emergencies. Methods: In 2019, the National Psychological Care Project for the Elderly was launched, covering 818 communities across the country, and 188 407 subjects received psychological assessment. In April and May 2020, a convenient sample of 6 467 aged 65 and above subjects were followed up on the anxiety status and its influencing factors during the epidemic period by using structurized questionnaire. Data collection and management were carried out using the national elderly psychological care project data collection platform. McNemar test was used to compare the difference of the prevalence of anxiety among elderly before (October 2019 to January 23, 2020) and during the epidemic (April-May 2020). The difference of the prevalence of anxiety among elderly with different characteristics was compared by chi square test. The influencing factors of anxiety before and during the epidemic situation were analyzed by multivariate logistic regression model. Results: The prevalence of anxiety symptoms in the elderly population was 4.95% (95%CI: 4.42%-5.48%) before the outbreak of COVID-19, and 10.10% (95%CI: 9.36%-10.83%) during the epidemic which was twice as high as before the outbreak. The difference was statistically significant (P<0.05). Multivariate logistic regression analysis showed that the risk factors of anxiety symptoms before the outbreak were with one underlying disease (OR=1.57, 95%CI: 1.05-2.37), with two or more underlying diseases (OR=3.10, 95%CI: 2.13-4.51), and the protective factors were with hobbies, good relationship between children, good relationship with spouse, positive aging attitude and good psychological resilience (all P<0.05). The risk factors of developing anxiety symptoms during the epidemic were living in rural areas (OR=1.77, 95%CI: 1.42-2.20), participating in social activities regularly (OR=1.23, 95%CI: 1.02-1.48), having a good relationship with friends (OR=1.42, 95%CI: 1.11-1.82) and were quarantined or people around were quarantined for medical observation (OR=2.80, 95% CI: 1.90-4.13). Conclusion: The COVID-19 epidemic leads to a double increase in anxiety among the elderly. We should pay more attention to the psychological state of the elderly in rural area and who is being quarantined or people around being quarantined for medical observation.

Porcine Deltacoronavirus Accessory Protein NS7a Antagonizes IFN-beta Production by Competing With TRAF3 and IRF3 for Binding to IKKepsilon

As an emerging swine enteropathogenic coronavirus, porcine deltacoronavirus (PDCoV) not only causes serious diarrhea in suckling piglets but also possesses the potential for cross-species transmission, which has sparked growing interest when studying this emerging virus. We previously identified a novel accessory protein NS7a encoded by PDCoV;however, the function of NS7a was not resolved. In this study, we demonstrated that PDCoV NS7a is an interferon antagonist. Overexpression of NS7a notably inhibited Sendai virus (SeV)-induced interferon-beta (IFN-beta) production and the activation of IRF3 rather than NF-kappaB. NS7a also inhibited IFN-beta promoter activity induced by RIG-I, MDA5, MAVS, TBK1, and IKKepsilon, which are key components of the RIG-I-like receptor (RLR) signaling pathway but not IRF3, the transcription factor downstream of TBK1/IKKepsilon. Surprisingly, NS7a specifically interacts with IKKepsilon but not with the closely related TBK1. Furthermore, NS7a interacts simultaneously with the kinase domain (KD) and the scaffold dimerization domain (SDD) of IKKepsilon, competing with TRAF3, and IRF3 for binding to IKKepsilon, leading to the reduction of RLR-mediated IFN-beta production. The interactions of TRAF3-IKKepsilon and IKKepsilon-IRF3 are also attenuated in PDCoV-infected cells. Taken together, our results demonstrate that PDCoV NS7a inhibits IFN-beta production by disrupting the association of IKKepsilon with both TRAF3 and IRF3, revealing a new mechanism utilized by a PDCoV accessory protein to evade the host antiviral innate immune response.