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1.
Applied Sciences ; 13(11):6680, 2023.
Article in English | ProQuest Central | ID: covidwho-20235802

ABSTRACT

Existing deep learning-based methods for detecting fake news are uninterpretable, and they do not use external knowledge related to the news. As a result, the authors of the paper propose a graph matching-based approach combined with external knowledge to detect fake news. The approach focuses on extracting commonsense knowledge from news texts through knowledge extraction, extracting background knowledge related to news content from a commonsense knowledge graph through entity extraction and entity disambiguation, using external knowledge as evidence for news identification, and interpreting the final identification results through such evidence. To achieve the identification of fake news containing commonsense errors, the algorithm uses random walks graph matching and compares the commonsense knowledge embedded in the news content with the relevant external knowledge in the commonsense knowledge graph. The news is then discriminated as true or false based on the results of the comparative analysis. From the experimental results, the method can achieve 91.07%, 85.00%, and 89.47% accuracy, precision, and recall rates, respectively, in the task of identifying fake news containing commonsense errors.

2.
Int J Biol Macromol ; 244: 125182, 2023 Jul 31.
Article in English | MEDLINE | ID: covidwho-20230950

ABSTRACT

The COVID-19 pandemic, caused by SARS-CoV-2, has become a global public health crisis. The entry of SARS-CoV-2 into host cells is facilitated by the binding of its spike protein (S1-RBD) to the host receptor hACE2. Small molecule compounds targeting S1-RBD-hACE2 interaction could provide an alternative therapeutic strategy sensitive to viral mutations. In this study, we identified G7a as a hit compound that targets the S1-RBD-hACE2 interaction, using high-throughput screening in the SARS2-S pseudovirus model. To enhance the antiviral activity of G7a, we designed and synthesized a series of novel 7-azaindole derivatives that bind to the S1-RBD-hACE2 interface. Surprisingly, ASM-7 showed excellent antiviral activity and low cytotoxicity, as confirmed by pseudovirus and native virus assays. Molecular docking and molecular dynamics simulations revealed that ASM-7 could stably bind to the binding interface of S1-RBD-hACE2, forming strong non-covalent interactions with key residues. Furthermore, the binding of ASM-7 caused alterations in the structural dynamics of both S1-RBD and hACE2, resulting in a decrease in their binding affinity and ultimately impeding the viral invasion of host cells. Our findings demonstrate that ASM-7 is a promising lead compound for developing novel therapeutics against SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/metabolism , Molecular Docking Simulation , Spike Glycoprotein, Coronavirus/chemistry , Pandemics , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Protein Binding
3.
Curr Med Imaging ; 2023 Apr 26.
Article in English | MEDLINE | ID: covidwho-2317962

ABSTRACT

BACKGROUND: COVID-19 is a global pandemic. Currently, the predominant strain is SARS-CoV-2 Omicron subvariant BA.2 in many countries. Understanding its infection characteristics can facilitate clinical management. OBJECTIVES: This study aimed to characterize the clinical, laboratory, and high-resolution computed tomography (HRCT) findings in patients with mild or moderate infection from SARS-CoV-2 Omicron subvariant BA.2. METHODS: We performed a retrospective study on patients infected with SARS-CoV-2 Omicron subvariant BA.2 between April 4th and April 17th, 2022. The clinical characteristics, laboratory features, and HRCT images were reviewed. RESULTS: A total of 805 patients were included (411 males and 394 females, median age 33 years old). The infection was mild, moderate, severe, and asymptomatic in 490 (60.9%), 37 (4.6%), 0 (0.0%), and 278 (34.5%) patients, respectively. Notably, 186 (23.1%), 96 (11.9%), 265 (32.9%), 11 (3.4%), 7 (0.9%), and 398 (49.4%) patients had fever, cough, throat discomfort, stuffy or runny nose, fatigue, and no complaint, respectively. Furthermore, 162 (20.1%), 332 (41.2%), and 289 (35.9%) patients had decreased white blood cell counts, reduced lymphocytes, and elevated C-reactive protein levels, respectively. HRCT revealed pneumonia in 53 (6.6%) patients. The majority of the lung involvements were ground-glass opacity (50, 94.3%) mostly in the subpleural area. The grade of lung injury was mainly mild (90.6%). Short-term follow-ups showed that most patients with pneumonia recovered. CONCLUSION: Most patients with mild or moderate infection from SARS-CoV-2 Omicron subvariant BA.2 were adults, with fever and upper respiratory symptoms as the main clinical presentations. Lower respiratory infection was mild, with ground-glass opacity in the subpleural area as the main finding.

4.
J Glob Health ; 13: 06012, 2023 Apr 14.
Article in English | MEDLINE | ID: covidwho-2295336

ABSTRACT

Background: Obesity is an independent risk factor for severe coronavirus disease 2019 (COVID-19), but there is little evidence on whether prior bariatric surgery benefits the outcomes of patients with COVID-19. We aimed to summarize this relationship by conducting a systematic review and meta-analysis of current case-control studies. Methods: We searched several electronic databases for case-control studies conducted between January 2020 and March 2022. We compared the rates of mortality, mechanical ventilation, intensive care unit (ICU) admission, dialysis, hospitalization, and length of hospital stay between COVID-19 patients with and without a history of bariatric surgery. Results: We included six studies with 137 903 patients; 5270 (3.8%) had prior bariatric surgery, while 132 633 (96.2%) did not. COVID-19 patients with a history of bariatric surgery had significantly lower mortality (odds ratio (OR) = 0.42; 95% confidence interval (CI) = 0.23-0.74), ICU admission (OR = 0.48; 95% CI = 0.36-0.65), and mechanical ventilation rates than those with a history of non-bariatric surgery (OR = 0.51; 95% CI = 0.35-0.75). Conclusions: Prior bariatric surgery was associated with a reduced risk of mortality and reduced severity of COVID-19 in patients with obesity compared to those with no prior bariatric surgery. Further large-sample prospective studies are needed to support these results. Registration: CRD42022323745.


Subject(s)
Bariatric Surgery , COVID-19 , Humans , Bariatric Surgery/adverse effects , Bariatric Surgery/methods , Hospitalization , Obesity/complications , Obesity/epidemiology , Case-Control Studies
5.
British Journal of Social Work ; 53(2):1036-1054, 2023.
Article in English | CINAHL | ID: covidwho-2283521

ABSTRACT

The COVID-19 pandemic may have resulted in front line social workers experiencing job stress, burnout and other psychological distress. Little is known about the work-related stress experienced by Chinese social workers during the pandemic. This study focused on the job stress of social workers from Mainland and Macao. The research aims of this study included: (1) testing whether there is a difference in job stress between social workers from Mainland and Macao during the pandemic and (2) identifying mediating factors that helped explain such regional differences. An online survey collected data from 292 social workers in Mainland China and 108 from Macao in 2020. Mainland participants reported significantly higher job stress than Macao participants. Regional differences in job stress amongst Mainland and Macao social workers were partially attributed to their age and professional role identity. More attention needs to be paid to social workers in Mainland China as they experience higher job stress than their counterparts from Macao. Future research is needed to examine other factors (e.g. job demand and financial compensation) that may contribute to such regional differences.

6.
J Intensive Med ; 1(1): 35-41, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-2286288

ABSTRACT

Coagulopathy, characterized by a high D-dimer level, is a common pathological occurrence in coronavirus disease 2019 (COVID-19) and is associated with poor prognosis. Severe cases with COVID-19 is associated with a significantly higher risk of deep vein thrombosis and acute pulmonary embolism. Pulmonary intravascular coagulopathy is the characteristic coagulopathy in COVID-19. Unlike sepsis-induced coagulopathy and disseminated intravascular coagulation, which are manifestations of systemic coagulopathy, pulmonary intravascular coagulopathy is a manifestation of a local coagulation disorder in the lung. The progression from pulmonary intravascular coagulopathy to sepsis-induced coagulopathy or disseminated intravascular coagulation in the context of COVID-19 may indicate that the patient's coagulation dysfunction has progressed from local to systemic. Exploring the associated coagulation disease will aid in the understanding of the pathophysiological mechanisms underlying severe COVID-19.

7.
MedComm ; 4(1), 2023.
Article in English | EuropePMC | ID: covidwho-2232654

ABSTRACT

The recent pandemic of variants of concern (VOC) of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) highlights the need for innovative anti‐SARS‐CoV‐2 approaches in addition to vaccines and antiviral therapeutics. Here, we demonstrate that a CRISPR‐Cas13‐based strategy against SARS‐CoV‐2 can effectively degrade viral RNA. First, we conducted a cytological infection experiment, screened CRISPR‐associated RNAs (crRNAs) targeting conserved regions of viruses, and used an in vitro system to validate functional crRNAs. Reprogrammed Cas13d effectors targeting NSP13, NSP14, and nucleocapsid transcripts achieved >99% silencing efficiency in human cells which are infected with coronavirus 2, including the emerging variants in the last 2 years, B.1, B.1.1.7 (Alpha), D614G B.1.351 (Beta), and B.1.617 (Delta). Furthermore, we conducted bioinformatics data analysis. We collected the sequence information of COVID‐19 and its variants from China, and phylogenetic analysis revealed that these crRNA oligos could target almost 100% of the SARS‐CoV family, including the emerging new variant, Omicron. The reprogrammed Cas13d exhibited high specificity, efficiency, and rapid deployment properties;therefore, it is promising for antiviral drug development. This system could possibly be used to protect against unexpected SARS‐CoV‐2 variants carrying multiple mutations. Cas13d‐crRNAs inhibit both ancestral and mutated SARS‐CoV‐2 replication. Cas13d‐crRNAs inhibit both ancestral and mutated SARS‐CoV‐2 replication including Delta. Cas13d‐crRNAs could inhibit Omicron and other SARS family strains and are a potential pan‐SARS inhibition strategy.

8.
MedComm (2020) ; 4(1): e208, 2023 Feb.
Article in English | MEDLINE | ID: covidwho-2232655

ABSTRACT

The recent pandemic of variants of concern (VOC) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the need for innovative anti-SARS-CoV-2 approaches in addition to vaccines and antiviral therapeutics. Here, we demonstrate that a CRISPR-Cas13-based strategy against SARS-CoV-2 can effectively degrade viral RNA. First, we conducted a cytological infection experiment, screened CRISPR-associated RNAs (crRNAs) targeting conserved regions of viruses, and used an in vitro system to validate functional crRNAs. Reprogrammed Cas13d effectors targeting NSP13, NSP14, and nucleocapsid transcripts achieved >99% silencing efficiency in human cells which are infected with coronavirus 2, including the emerging variants in the last 2 years, B.1, B.1.1.7 (Alpha), D614G B.1.351 (Beta), and B.1.617 (Delta). Furthermore, we conducted bioinformatics data analysis. We collected the sequence information of COVID-19 and its variants from China, and phylogenetic analysis revealed that these crRNA oligos could target almost 100% of the SARS-CoV family, including the emerging new variant, Omicron. The reprogrammed Cas13d exhibited high specificity, efficiency, and rapid deployment properties; therefore, it is promising for antiviral drug development. This system could possibly be used to protect against unexpected SARS-CoV-2 variants carrying multiple mutations.

9.
Sleep Med ; 101: 28-35, 2022 Oct 13.
Article in English | MEDLINE | ID: covidwho-2230219

ABSTRACT

BACKGROUNDS: The COVID-19 pandemic has caused significant impact on human health. Whether obstructive sleep apnea (OSA) increases the risk of COVID-19 remains unclear. We sought to clarify this issue using two-sample Mendelian randomization (TSMR) analysis in large cohorts. METHODS: Bidirectional two-sample Mendelian randomization (MR) was used to evaluate the potential causality between OSA and COVID-19 by selecting single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) from genome-wide association studies (GWAS). The inverse-variance weighted (IVW) method was selected as the main approach for data analysis to estimate the possible causal effects. Alternative methods such as MR-Egger, the MR pleiotropy residual sum and outlier (MR-PRESSO), and leave-one-out analysis methods were implemented as sensitivity analysis approaches to ensure the robustness of the results. RESULTS: All forward MR analyses consistently indicated the absence of a causal relationship between OSA and any COVID-19 phenotype. In the reverse MR analysis, the IVW mode demonstrated that severe respiratory confirmed COVID-19 was correlated with a 4.9% higher risk of OSA (OR, 1.049; 95%CI, 1.018-1.081; P = 0.002), consistent in MR-PRESSO (OR = 1.049, 95%CI 1.018-1.081, P = 0.004), weighted median (OR = 1.048, 95%CI 1.003-1.095, P = 0.035), and MR-Egger (OR = 1.083, 95%CI 1.012-1.190, P = 0.041) methods. CONCLUSIONS: There is no significant evidence supporting a causal association between OSA and any COVID phenotype, while we identified potential evidence for a causal effect of severe COVID-19 on an increased risk of OSA.

10.
Nutr Metab (Lond) ; 19(1): 84, 2022 Dec 28.
Article in English | MEDLINE | ID: covidwho-2196354

ABSTRACT

BACKGROUND: Evidence from previous studies has suggested that ginger extract exhibits the potential as an alternative treatment for Coronavirus disease 2019 (COVID-19). Here, we want to investigate whether ginger supplement improves the clinical manifestation of hospitalized COVID-19 individuals. METHODS: A total of 227 hospitalized individuals with COVID-19 were randomized to either the control (n = 132) or intervention group (n = 95). The intervention group took ginger supplement orally at the dosage of 1.5 g twice daily, until they were discharged from the hospital. Both groups received the same standard of general medical care during hospitalization, and the length of stay was recorded and compared between groups. RESULTS: Among all participants, a significant reduction in hospitalization time (the difference between the treatment and control groups was 2.4 d, 95% CI 1.6-3.2) was detected in response to the ginger supplement. This effect was more pronounced in men, participants aged 60 years or older, and participants with pre-existing medical conditions, relative to their counterparts (P-interactions < 0.05 for all). CONCLUSION: Ginger supplement significantly shortened the length of stay of hospitalized individuals with COVID-19. TRIAL REGISTRATION: The trial was registered on the Chinese Clinical Trial Registry (ChiCTR2200059824).

11.
The British Journal of Social Work ; 2022.
Article in English | Web of Science | ID: covidwho-2032020

ABSTRACT

The COVID-19 pandemic may have resulted in front line social workers experiencing job stress, burnout and other psychological distress. Little is known about the work-related stress experienced by Chinese social workers during the pandemic. This study focused on the job stress of social workers from Mainland and Macao. The research aims of this study included: (1) testing whether there is a difference in job stress between social workers from Mainland and Macao during the pandemic and (2) identifying mediating factors that helped explain such regional differences. An online survey collected data from 292 social workers in Mainland China and 108 from Macao in 2020. Mainland participants reported significantly higher job stress than Macao participants. Regional differences in job stress amongst Mainland and Macao social workers were partially attributed to their age and professional role identity. More attention needs to be paid to social workers in Mainland China as they experience higher job stress than their counterparts from Macao. Future research is needed to examine other factors (e.g. job demand and financial compensation) that may contribute to such regional differences. This article studied the job stress of social workers, during COVID-19, in two different Chinese regions. A survey collected data from 292 social workers in Mainland China and 108 social workers in Macao in 2020. The findings showed that the Mainland social workers reported higher job stress than their Macao counterparts. Regional differences in job stress were partially attributed to their age and professional role identity. Future research is needed to examine other factors (e.g. job demand and financial compensation) that may contribute to such regional differences.

12.
Signal Transduct Target Ther ; 7(1): 312, 2022 09 07.
Article in English | MEDLINE | ID: covidwho-2008259

ABSTRACT

The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a global pandemic that seriously threatens health and socioeconomic development, but the existed antiviral drugs and vaccines still cannot yet halt the spread of the epidemic. Therefore, a comprehensive and profound understanding of the pathogenesis of SARS-CoV-2 is urgently needed to explore effective therapeutic targets. Here, we conducted a multiomics study of SARS-CoV-2-infected lung epithelial cells, including transcriptomic, proteomic, and ubiquitinomic. Multiomics analysis showed that SARS-CoV-2-infected lung epithelial cells activated strong innate immune response, including interferon and inflammatory responses. Ubiquitinomic further reveals the underlying mechanism of SARS-CoV-2 disrupting the host innate immune response. In addition, SARS-CoV-2 proteins were found to be ubiquitinated during infection despite the fact that SARS-CoV-2 itself didn't code any E3 ligase, and that ubiquitination at three sites on the Spike protein could significantly enhance viral infection. Further screening of the E3 ubiquitin ligases and deubiquitinating enzymes (DUBs) library revealed four E3 ligases influencing SARS-CoV-2 infection, thus providing several new antiviral targets. This multiomics combined with high-throughput screening study reveals that SARS-CoV-2 not only modulates innate immunity, but also promotes viral infection, by hijacking ubiquitination-specific processes, highlighting potential antiviral and anti-inflammation targets.


Subject(s)
COVID-19 , SARS-CoV-2 , Antiviral Agents , Humans , Proteomics , Ubiquitin-Protein Ligases , Ubiquitination/genetics
13.
Frontiers in pharmacology ; 13, 2022.
Article in English | EuropePMC | ID: covidwho-1998561

ABSTRACT

Coronavirus disease 2019 (COVID-19) was caused by a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 utilizes human angiotensin converting enzyme 2 (hACE2) as the cellular receptor of its spike glycoprotein (SP) to gain entry into cells. Consequently, we focused on the potential of repurposing clinically available drugs to block the binding of SARS-CoV-2 to hACE2 by utilizing a novel artificial-intelligence drug screening approach. Based on the structure of S-RBD and hACE2, the pharmacophore of SARS-CoV-2-receptor-binding-domain (S-RBD) -hACE2 interface was generated and used to screen a library of FDA-approved drugs. A total of 20 drugs were retrieved as S-RBD-hACE2 inhibitors, of which 16 drugs were identified to bind to S-RBD or hACE2. Notably, tannic acid was validated to interfere with the binding of S-RBD to hACE2, thereby inhibited pseudotyped SARS-CoV-2 entry. Experiments involving competitive inhibition revealed that tannic acid competes with S-RBD and hACE2, whereas molecular docking proved that tannic acid interacts with the essential residues of S-RBD and hACE2. Based on the known antiviral activity and our findings, tannic acid might serve as a promising candidate for preventing and treating SARS-CoV-2 infection.

14.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(6):671-678, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1975502

ABSTRACT

In present study, in order to develop a new and effective porcine epidemic diarrhea virus (PEDV)vaccine, three B cell epitopes and the truncated S1 gene of PEDV spike protein were combined and inserted into the immunodominant region of the HBcAg. Then the constructed recombinant plasmid HBcAg-PE was transformed to E. coli BL21 (DE3) for expression. After purification and identification by Western-blot, the expressed recombinant proteins HBPE were injected into BALB/c mice as vaccine antigen with different doses through intramuscular injection and its immune effect were preliminary evaluated. The results showed that the recombinant proteins HBPE was expressed as precipitation form and it could reacted specifically with PEDV-positive serum after purification and renaturation. Besides, the RH could induce anti-PEDV specific antibodies and the related Thl and Th2 cytokines in mice. The above results indicate that the recombinant compound epitope antigen of PEDV was successfully constructed. and its immunogenicity as a new vaccine candidate was evaluated in the mice in this study. The results of this study provided a new idea for the development of PEDV genetic engineering vaccine in the future.

15.
J Infect ; 85(4): 418-427, 2022 10.
Article in English | MEDLINE | ID: covidwho-1959736

ABSTRACT

The ongoing global pandemic of Coronavirus disease 2019 (COVID-19) poses a serious threat to human health, with patients reportedly suffering from thrombus, vascular injury and coagulation in addition to acute and diffuse lung injury and respiratory diseases. Angiotensin converting enzyme 2 (ACE2) as the receptor for SARS-CoV-2 entry, is also an important regulator of renin-angiotensin system (RAS) homeostasis, which plays an unsettled role in the pathogenesis of COVID-19. Here, we demonstrated that SARS-CoV-2 Spike protein activated intracellular signals to degrade ACE2 mRNA. The decrease of ACE2 and higher level of angiotensin (Ang) II were verified in COVID-19 patients. High dose of Ang II induced pulmonary artery endothelial cell death in vitro, which was also observed in the lung of COVID-19 patients. Our finding indicates that the downregulation of ACE2 potentially links COVID-19 to the imbalance of RAS.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Angiotensin-Converting Enzyme 2/genetics , Down-Regulation , Humans , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
16.
Disease Surveillance ; 37(1):17-21, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-1789478

ABSTRACT

Objective: To understand the infection status of major respiratory pathogens in pneumonia patients in the early phase of coronavirus disease 2019 (COVID-19) epidemic (January-March, 2020) in Tongzhou district of Beijing.

17.
Front Public Health ; 9: 666135, 2021.
Article in English | MEDLINE | ID: covidwho-1771101

ABSTRACT

BACKGROUND: The implementation of evidence-based approaches by general practitioners (GPs) is new in the primary care setting, and few quantitative studies have evaluated the impact of contextual factors on the attendance of these approaches. METHODS: In total, 892 GPs from 75 community healthcare centers (CHCs) in Shanghai completed our survey. We used logistic regression to analyze factors affecting the number of evidence-based chronic disease programs attended by GPs and whether they had held the lead position in such a program. RESULTS: A total of 346 (38.8%) of the practitioners had never participated in any evidence-based chronic disease prevention (EBCDP) program. The EBCDP interventions in which the GPs had participated were predominantly related to hypertension, diabetes, and cardiovascular disease. However, the proportion of GPs in the lead role was relatively low, between 0.8% (programs involving prevention and control of asthma) and 5.0% (diabetes). Organizational factors and areas were significantly associated with evidence-based practices (EBPs) of the GP, while monthly income and department were the most significantly related to GPs who have the lead role in a program. The results indicated that GPs who had taken the lead position had higher scores for policy and economic impeding factors. GPs who were men, had a higher income, and worked in prevention and healthcare departments and urban areas were more likely to take the lead position. CONCLUSION: Evidence-based programs for chronic diseases should be extended to different types of diseases. Personal, organizational, political, and economic factors and the factors of female sex, lower income, department type, and suburban area environment should be considered to facilitate the translation of evidence to practice.


Subject(s)
General Practitioners , China , Chronic Disease , Female , Humans , Male , Primary Health Care
18.
Mamm Genome ; 33(1): 143-156, 2022 03.
Article in English | MEDLINE | ID: covidwho-1767484

ABSTRACT

Mouse models are essential for dissecting disease mechanisms and defining potential drug targets. There are more than 18,500 mouse strains available for research communities in National Resource Center for Mutant Mice (NRCMM) of China, affiliated with Model Animal Research Center of Nanjing University and Gempharmatech Company. In 2019, Gempharmatech launched the Knockout All Project (KOAP) aiming to generate null mutants and gene floxed strains for all protein-coding genes in mouse genome within 5 years. So far, KOAP has generated 8,004 floxed strains and 9,769 KO (knockout) strains (updated to Oct, 2021). NRCMM also created hundreds of Cre transgenic lines, mutant knock-in models, immuno-deficient models, and humanized mouse models. As a member of the international mouse phenotyping consortium (IMPC), NRCMM provides comprehensive phenotyping services for mouse models. In summary, NRCMM will continue to support biomedical community with new mouse models as well as related services.


Subject(s)
Genome , Animals , China , Disease Models, Animal , Humans , Mice , Mice, Knockout , Phenotype
19.
Atmos Environ (1994) ; 278: 119076, 2022 Jun 01.
Article in English | MEDLINE | ID: covidwho-1763592

ABSTRACT

After the global outbreak of COVID-19, the Chinese government took many measures to control the spread of the virus. The measures led to a reduction in anthropogenic emissions nationwide. Data from a single particle aerosol mass spectrometer in an eastern Chinese megacity (Hangzhou) before, during, and after the COVID-19 lockdown (5 January to February 29, 2020) was used to understand the effect lockdown had on atmospheric particles. The collected single particle mass spectra were clustered into eight categories. Before the lockdown, the proportions of particles ranked in order of: EC (57.9%) < K-SN (13.6%) < Fe-rich (10.2%) < ECOC (6.7%) < K-Na (6.6%) < OC (3.4%) < K-Pb (1.0%) < K-Al (0.7%). During the lockdown period, the EC and Fe-rich particles decreased by 42.8% and 93.2% compared to before lockdown due to reduced vehicle exhaust and industrial activity. By contrast, the K-SN and K-Na particles containing biomass burning tracers increased by 155.2% and 45.2% during the same time, respectively. During the lockdown, the proportions of particles ranked in order of: K-SN (39.7%) < EC (38.1%) < K-Na (11.0%) < ECOC (7.7%) < OC (1.2%) < K-Pb (0.9%) < Fe-rich (0.8%) < K-Al (0.6%). Back trajectory analysis indicated that both inland (Anhui and Shandong provinces) and marine transported air masses may have contributed to the increase in K-SN and K-Na particles during the lockdown, and that increased number of fugitive combustion points (i.e., household fuel, biomass combustion) was a contributing factor. Therefore, the results imply that regional synergistic control measures on fugitive combustion emissions are needed to ensure good air quality.

20.
Infectious Medicine ; 2022.
Article in English | ScienceDirect | ID: covidwho-1699253

ABSTRACT

Objective Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 and has led to a global coronavirus disease 2019 (COVID-19) pandemic. Currently, incomplete understanding of how SARS-CoV-2 arrogates the host cell to establish its life cycle has led to slow progress in the development of effective drugs. Results In this study, we found that SARS-CoV-2 hijacks the host protein EWSR1 (Ewing Sarcoma breakpoint region 1/EWS RNA binding protein 1) to promote the activity of its helicase NSP13 to facilitate viral propagation. NSP13 is highly conserved among coronaviruses and is crucial for virus replication, providing chemical energy to unwind viral RNA replication intermediates. Treatment with different SARS-CoV-2 NSP13 inhibitors in multiple cell lines infected with SARS-CoV-2 effectively suppressed SARS-CoV-2 infection. Using affinity-purification mass spectrometry, the RNA binding protein EWSR1 was then identified as a potent host factor that physically associated with NSP13. Furthermore, silencing EWSR1 dramatically reduced virus replication at both viral RNA and protein levels. Mechanistically, EWSR1 was found to bind to the NTPase domain of NSP13 and potentially enhance its dsRNA unwinding ability. Conclusion In conclusion, our results pinpoint EWSR1 as a novel host factor for NSP13 that could potentially be used for drug repurposing as a therapeutic target for COVID-19.

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