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1.
Yaoxue Xuebao ; JOUR:3011-3018, 57(10).
Article in Chinese | EMBASE | ID: covidwho-2100541

ABSTRACT

Inosine 5'-monophosphate dehydrogenase (IMPDH) is a key enzyme catalyzing the rate-limiting step of de novo nucleotide synthesis in vivo. In recent years, it has become a therapeutic target for anti-virus, antibacterial, anti-cancer, anti-parasitic and other diseases. IMPDH inhibitors have been shown to inhibit viral proliferation in host cells by depleting guanosine 5'-monophosphate (GMP), the raw material required for viral replication in host cells, with broad-spectrum antiviral properties. In order to find novel anti-coronavirus drugs, this study screened 22 potential IMPDH inhibitors from 70 000 natural small molecule libraries based on IMPDH protein structure using molecular docking and ROC calculation for virtual screening. With ribavirin as the positive control drug, Huh7 cell and H460 cell models were used to verify the anti-coronavirus HCoV-229E and HCoV-OC43 activities of 22 selected target compounds. Among them, compounds 11, 12, 15 and 16 showed inhibitory activity against coronavirus HCoV-229E. The compounds 4, 12, 13 and 15 showed inhibitory activities against coronavirus HCoVOC43. 12 and 15 showed significant inhibitory activity against both two coronaviruses, and their efficacy was similar to ribavirin at the same dose, which can be further studied as a lead compound for IMPDH inhibitors. Copyright © 2022, Chinese Pharmaceutical Association. All rights reserved.

2.
Current Topics in Nutraceutical Research ; 20(4):662-665, 2022.
Article in English | EMBASE | ID: covidwho-2044385

ABSTRACT

Interactions of platelets with circulating cells and vessel walls are implicated in various inflammatory processes. In certain circumstances, the hemostatic and inflammatory functions of platelets may overlap. Platelet-lymphocyte/leukocyte interactions can effectively regulate chronic inflammatory conditions. Platelet extracellular vesicles play a prominent role in thrombosis. In this review, we provide an overview of the molecules associated with platelet-cell interaction and the role of platelet extracellular vesicles in cardiovascular disorders and coronavirus disease 2019, which has posed a significant threat to global health due to infection with severe acute respiratory syndrome coronavirus 2. In addition to recruiting leukocytes to resolve inflammation associated with inflammatory diseases, such as coronavirus disease 2019, nutrients may also play a significant role in human metabolism.

3.
IEEE Transactions on Network Science and Engineering ; : 1-13, 2022.
Article in English | Scopus | ID: covidwho-2037845

ABSTRACT

Infectious diseases pose a severe threat to human health, especially the outbreak of COVID-19. After the infectious disease enters the stage of large-scale epidemics, vaccination is an effective way to control infectious diseases. However, when formulating a vaccination strategy, some restrictions still exist, such as insufficient vaccines or insufficient government funding to afford everyone's vaccination. Therefore, in this paper, we propose a vaccination optimization problem with the lowest total cost based on the susceptible-infected-recovered (SIR) model, which is called the Lowest Cost Of Vaccination Strategy (LCOVS) problem. We first establish a mathematical model of the LCOVS problem. Then we propose a practical Differential Evolution based Simulated Annealing (DESA) method to solve the mathematical optimization problem. We use the simulated annealing algorithm (SA) as a local optimizer for the results obtained by the differential evolution algorithm (DE) and optimized the mutation and crossover steps of DE. Finally, the experimental results on the six data sets demonstrate that our proposed DESA can achieve a more low-cost vaccination strategy than the baseline algorithms. IEEE

4.
28th ACM SIGKDD Conference on Knowledge Discovery and Data Mining, KDD 2022 ; : 3357-3365, 2022.
Article in English | Scopus | ID: covidwho-2020395

ABSTRACT

The outbreak of COVID-19 burgeons newborn services on online platforms and simultaneously buoys multifarious online fraud activities. Due to the rapid technological and commercial innovation that opens up an ever-expanding set of products, the insufficient labeling data renders existing supervised or semi-supervised fraud detection models ineffective in these emerging services. However, the ever accumulated user behavioral data on online platforms might be helpful in improving the performance of fraud detection on newborn services. To this end, in this paper, we propose to pre-train user behavior sequences, which consist of orderly arranged actions, from the large-scale unlabeled data sources for online fraud detection. Recent studies illustrate accurate extraction of user intentions∼(formed by consecutive actions) in behavioral sequences can propel improvements in the performance of online fraud detection. By anatomizing the characteristic of online fraud activities, we devise a model named UB-PTM that learns knowledge of fraud activities by three agent tasks at different granularities, i.e., action, intention, and sequence levels, from large-scale unlabeled data. Extensive experiments on three downstream transaction and user-level online fraud detection tasks demonstrate that our UB-PTM is able to outperform the state-of-the-art designing for specific tasks. © 2022 ACM.

5.
Electrochimica Acta ; 428, 2022.
Article in English | Scopus | ID: covidwho-1991021

ABSTRACT

Li–air batteries have received significant attention for their ultrahigh theoretical energy density. However, the byproducts induced by attacking air hinder the conversion of Li–O2 batteries to Li–air batteries. Humidity is one of the main obstacles, not only causing side reactions with the discharge products but also leading to rapid corrosion of the lithium anode. Here, we fabricated a novel composite hydrophobic catalyst by loading RuO2 and graphene on N-doped porous carbon. The catalyst was endowed with hydrophobicity and showed superior catalytic performance and low affinity to water in the air. A Li–air battery equipped with this novel composite catalyst exhibited eminent cycling performance in pure oxygen (over 470 h), humid oxygen [∼40% relative humidity (RH), over 310 h], and ambient air (∼42% RH, over 330 h) at a current density of 500 mA g−1, and the discharge specific capacity increased from 13122.1 to 19358.6 mAh g−1. © 2022

6.
International Conference on Wireless Communications, Networking and Applications, WCNA 2021 ; 942 LNEE:95-103, 2022.
Article in English | Scopus | ID: covidwho-1971629

ABSTRACT

Under the situation of the normalization of the prevention and control of COVID-19, related online public opinion occurs from time to time. University administrators must grasp the right of online discourse to guide the direction of online public opinion and ensure the stability of campus order. This paper analyzes the necessity and feasibility of university administrators to grasp the right of online discourse from the basis of reality, compares two kinds of measures and their combinations through questionnaires and computer simulation experiments: publishing authoritative information and focusing on opinion leaders, argues the effectiveness of these two types of measures, and puts forward specific countermeasure suggestions on this basis. © 2022, The Author(s).

7.
China Journal of Leprosy and Skin Diseases ; 38(8):499-502, 2022.
Article in Chinese | Scopus | ID: covidwho-1954980

ABSTRACT

Background: Eight pm on April 13, 2022,a10:1 mixed test tube was found to be positive in the COVID-19 nucleic acid test site set up outside the hospital. In order to identify the infected case and control the spread of COVID-19 rapidly, we conducted this emergency investigation. Methods: According to the National COVID-19 Control and Prevention Protocol (8th edition), Guideline on Emergency Response to COVID-19 Case Found in Hospital in Shandong Province, and the Emergency Response Plan for COVID-19 in our hospital, information reporting, hospitalblockading, potential COVID- 19 cases tracing, close contact screening, environmental sampling and disinfecting, COVID-19 nucleic acid testing and risk assessment were carried out by our team. Results: A female COVID-19 case aged 50 years was identified. She is aodd-jobber who works in the labour market near the hospital. The virus strain was sequenced as Omicron BA.2. A total of 65 close contacts was controlled in a hotel. The COVID-19 nucleic acid test results for all the staff of hospital, environmental samples were negative. The risk of COVID-19 spread was controlled and the hospital restarted of clinical activities as normal at 8 am on April 14 after blockaded for 12 hours. Inthe following 7 days, the staff of the hospital were tested for COVID-19 nucleic acid twice a day, and the results were negative. Then the testing frequency changed to once a day. Conclusion: Formulating detailed and feasible COVID-19 emergency response plans based on the requirements of the public documents and the actual conditions of the hospital, is useful to improve the efficiency of emergency response to COVID-19 cases and save time for control of COVID-19 spread and restart the clinical activities of hospital. © 2022 Shandong Yinbao Technology Co. Ltd. All Rights Reserved.

8.
Acs Applied Polymer Materials ; : 9, 2022.
Article in English | Web of Science | ID: covidwho-1927039

ABSTRACT

Since the emergence of the COVID-19 pandemic, there has been a tremendous increase in the production of masks worldwide, with more than 1.5 billion masks having been disposed of during this time. The damage caused by mask pollution is a global threat;highlighting the need to dispose of discarded masks correctly. Herein, we report a recycling approach that uses discarded masks to fabricate a superhydrophobic epoxy resin/SiO2 membrane for separating emulsions. The composite has a high flux value (2123 L. m(-2).h(-1)) and high separation efficiency (>98%). The filter maintained its excellent superhydrophobic property (WCA > 150 degrees) after tape-peel cycles, clamping cycles with tweezers, abrasion cycles with 800 grit SiC sandpaper, pressure with fingertips, and kneading cycles. This study proposes a renewable, eco-friendly, and low-cost product, which can be used for oil spill cleanup and water purification. The filter not only removes oil from oily wastewater (such as oil spills) but also solves pollution caused by discarded masks. This study provides insights for resource recovery that may contribute to the purification of oily water emulsions.

9.
2022 International Conference on Algorithms, Microchips and Network Applications ; 12176, 2022.
Article in English | Scopus | ID: covidwho-1923085

ABSTRACT

In order to overcome the trend influence of novel Coronavirus epidemic in the future, this paper proposes the panel data modeling method based on big data crawler technology, which is based on Python crawler technology to obtain a more effective estimation model from the dynamic perspective of time and cross section. The results showed that the fixed effect error rate established by the development of COVID-19 in China, Japan, South Korea, Germany and Italy was about 3%, and there is a positive correlation between cured cases and confirmed cases of COVID-19. The predicted confirmed cases of COVID-19 in week 63 will be 69, 11,908, 3156, 112293 and 147,545, respectively. © COPYRIGHT SPIE. Downloading of the is permitted for personal use only.

11.
Topics in Antiviral Medicine ; 30(1 SUPPL):113-114, 2022.
Article in English | EMBASE | ID: covidwho-1880091

ABSTRACT

Background: Soluble Angiotensin Converting Enzyme 2 (ACE2) constitutes an attractive therapeutic candidate with natural resistance to viral escape. To date, ACE2-Fcs, dimeric forms of soluble ACE2, were mostly tested as robust SARS-CoV-2 neutralizers but their potential as antiviral agents capable of Fc-effector functions is largely unknown and has not been tested for effectiveness in vivo, in any model of SARS-CoV2 infection. Methods: We used structure-guided design to select ACE2 mutations that improve SARS-CoV-2 spike (S) affinity and remove angiotensin enzymatic activity. ACE2-Fc variants were engineered into a human IgG1 or IgG3 backbone and produced in mammalian HEK293 cells. S binding was tested by ELISA and surface plasmon resonance (SPR). Mutational effects were validated by X-Ray crystallography. Neutralization activities were measured against SARS-CoV-2 variants of concern (VOCs) using an in vitro pseudovirus (PsV) assay and dynamic bioluminescence imaging (BLI). Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) were also quantified using established methods (1, 2). A K18-hACE2 transgenic mouse model challenged by lethal SARS-CoV-2 nLuc infection (3) was used for in vivo evaluation of prophylactic and therapeutic administration of engineered ACE2-Fcs, as monitored by dynamic BLI. Results: Our lead variant, ACE2740 LFMYQY2HA-Fc GASDALIE, increased RBD binding by ∼7-13 fold as compared to wild type, cross-neutralized SARS-CoV-2 VOCs with an IC50 range of 0.23-2.06 nM and mediated robust ADCC and ADCP in vitro. When tested in humanized K18-hACE2 mice, in either a prophylatic or a multi-dosage therapeutic setting, our lead ACE2-Fc variant provided protection from lethal SARS-CoV-2 infection. Our studies in K18-hACE2 mouse model revealed that efficient in vivo efficacy of ACE2-Fcs under prophylaxis or therapeutic settings required Fc-effector functions in addition to neutralization. Conclusion: Our data confirm the utility of engineered ACE2-Fcs as valuable SARS-CoV-2 antivirals and demonstrate that the efficient ACE2-Fc therapeutic activity required both neutralization and Fc-effector functions.

12.
Applied biochemistry and microbiology ; 57(Suppl 1):S11-S26, 2021.
Article in English | EuropePMC | ID: covidwho-1871964

ABSTRACT

Naphthoquinones harboring 1,4-naphthoquinone pharmacophore are considered as privileged structures in medicinal chemistry. In pharmaceutical industry and fundamental research, polyketide naphthoquinones were widely produced by heterologous expression of polyketide synthases in microbial chassis cells, such as Saccharomyces cerevisiae and Escherichia coli. Nevertheless, these cell factories still remain, to a great degree, black boxes that often exceed engineers’ expectations. In this work, the biotransformation of juglone or 1,4-naphthoquinone was conducted to generate novel derivatives and it was revealed that these two naphthoquinones can indeed be modified by the chassis cells. Seventeen derivatives, including 6 novel compounds, were isolated and their structural characterizations indicated the attachment of certain metabolites of chassis cells to naphthoquinones. Some of these biosynthesized derivatives were reported as potent antimicrobial agents with reduced cytotoxic activities. Additionally, molecular docking as simple and quick in silico approach was performed to screen the biosynthesized compounds for their potential antiviral activity. It was found that compound 11 and 17 showed the most promising binding affinities against Nsp9 of SARS-CoV-2, demonstrating their potential antiviral activities. Overall, this work provides a new approach to generate novel molecules in the commonly used chassis cells, which would expand the chemical diversity for the drug development pipeline. It also reveals a novel insight into the potential of the catalytic power of the most widely used chassis cells. Supplementary Information The online version contains supplementary material available at 10.1134/S0003683821100124.

13.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336833

ABSTRACT

ABSTRACT HostSeq was launched in April 2020 as a national initiative to integrate whole genome sequencing data from 10,000 Canadians infected with SARS-CoV-2 with clinical information related to their disease experience. The mandate of HostSeq is to support the Canadian and international research communities in their efforts to understand the risk factors for disease and associated health outcomes and support the development of interventions such as vaccines and therapeutics. HostSeq is a collaboration among 13 independent epidemiological studies of SARS-CoV-2 across five provinces in Canada. Aggregated data collected by HostSeq are made available to the public through two data portals: a phenotype portal showing summaries of major variables and their distributions, and a variant search portal enabling queries in a genomic region. Individual-level data is available to the global research community through a Data Access Agreement and Data Access Compliance Office approval. Here we provide an overview of the collective project design along with summary level information for HostSeq. We highlight several statistical considerations for researchers using the HostSeq platform regarding data aggregation, sampling mechanism, covariate adjustment, and X chromosome analysis. In addition to serving as a rich data source, the diversity of study designs, sample sizes, and research objectives among the participating studies provides unique opportunities for the research community.

14.
21st IEEE International Conference on Bioinformatics and Bioengineering (IEEE BIBE) ; 2021.
Article in English | Web of Science | ID: covidwho-1764811

ABSTRACT

In silico approach can make vaccine designs more efficient and cost-effective. It complements the traditional process and becomes extremely valuable in coping with pandemics such as COVID-19. A recent study proposed an artificial intelligence-based framework to predict and design multi-epitope vaccines for the SARS-CoV-2 virus. However, we found several issues in its dataset design as well as its neural network design. To achieve more reliable predictions of the potential vaccine subunits, we create a more reliable and larger dataset for machine learning experiments. We apply natural language processing techniques and build neural networks composed of convolutional layer and recurrent layer to identify peptide sequences as vaccine candidates. We also train a classifier using embeddings from a pre-trained Transformer protein language model, which provides a baseline for comparison. Experimental results demonstrate that our models achieve high performance in classification accuracy and the area under the receiver operating characteristic curve.

16.
Aerosol and Air Quality Research ; 22(2), 2022.
Article in English | Scopus | ID: covidwho-1732359

ABSTRACT

Airborne transmission of COVID-19 plays an important role for the pandemic. However, nucleic acid based evidence of direct association of COVID-19 with environmental contamination is lacking. Here, we investigated a COVID-19 outbreak with two fast food employees infected, in which a traveler despite of a 14-day quarantine turned positive after check in with a hotel, using environmental SARS-CoV-2 sampling, epidemiological tracing, viral RNA sequence as well as surveillance method. Out of 25 positive environmental air and surface swab samples (N = 237) collected, SARS-CoV-2 was found to have remained airborne (5640–7840 RNA copies m–3 ) for more than 4 days in a female washroom. After aging for 5 days in the air, no viable virus was detected. The traveler did not have any contacts with the two employees;however, genome sequencing showed that SARS-CoV-2 variants from three patients and two environmental surface samples belonged to 20B viral clade, sharing a nucleic acid identity of more than 99.9%. We concluded that the outbreak was triggered by SARS-CoV-2 contaminated environments, where the employees inhaled the virus from the air or touching facility surfaces where the traveler did not have any physical contacts with. © The Author(s).

17.
21st IEEE International Conference on Data Mining, ICDM 2021 ; 2021-December:1102-1107, 2021.
Article in English | Scopus | ID: covidwho-1722911

ABSTRACT

Federated learning (FL) has emerged as a promising privacy-aware paradigm that allows multiple clients to jointly train a model without sharing their private data. Recently, many studies have shown that FL is vulnerable to membership inference attacks (MIAs) that can distinguish the training members of the given model from the non-members. However, existing MIAs ignore the source of a training member, i.e., the information of the client owning the training member, while it is essential to explore source privacy in FL beyond membership privacy of examples from all clients. The leakage of source information can lead to severe privacy issues. For example, identification of the hospital contributing to the training of an FL model for the COVID-19 pandemic can render the owner of a data record from this hospital more prone to discrimination if the hospital is in a high risk region. In this paper, we propose a new inference attack called source inference attack (SIA), which can derive an optimal estimation of the source of a training member. Specifically, we innovatively adopt the Bayesian perspective to demonstrate that an honest-but-curious server can launch an SIA to steal non-trivial source information of the training members without violating the FL protocol. The server leverages the prediction loss of local models on the training members to achieve the attack effectively and non-intrusively. We conduct extensive experiments on one synthetic and five real datasets to evaluate the key factors in an SIA, and the results show the efficacy of the proposed source inference attack. © 2021 IEEE.

19.
2021 ASEE Virtual Annual Conference, ASEE 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1695603

ABSTRACT

This work in progress describes the study of a Mechanical Engineering Technology Program's faculty experiences in the immediate aftermath of COVID-19. The effects of COVID-19 upon various institutions are likely to be longstanding, as returning to what once was considered normal will never completely happen. As part of the engineering technology community, it is important to contribute to the knowledge base regarding the collective experience. Just as novel observations may serve to identify opportunities for advancement or disparities between populations, recurring observations can add to literature validating pedagogical phenomena. This study utilized explorative qualitative methods to gain preliminary insight into the experiences at a particular institution. Findings can be used to inform practice as we try to move forward in the new normalcies of engineering education. © American Society for Engineering Education, 2021

20.
2021 ASEE Virtual Annual Conference, ASEE 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1695299
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