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1.
Sci Total Environ ; 838(Pt 3): 156193, 2022 Sep 10.
Article in English | MEDLINE | ID: covidwho-1852053

ABSTRACT

During the COVID-19 pandemic, the use of chlorine-based disinfectants has surged due to their excellent performance and cost-effectiveness in intercepting the spread of the virus and bacteria in water and air. Many authorities have demanded strict chlorine dosage for disinfection to ensure sufficient chlorine residual for inactivating viruses and bacteria while not posing harmful effects to humans as well as the environment. Reliable chlorine sensing techniques have therefore become the keys to ensure a balance between chlorine disinfection efficiency and disinfection safety. Up to now, there is still a lack of comprehensive review that collates and appraises the recently available techniques from a practical point of view. In this work, we intend to present a detailed overview of the recent advances in monitoring chlorine in both dissolved and gaseous forms aiming to present valuable information in terms of method accuracy, sensitivity, stability, reliability, and applicability, which in turn guides future sensor development. Data on the analytical performance of different techniques and environmental impacts associated with the dominated chemical-based techniques are thus discussed. Finally, this study concludes with highlights of gaps in knowledge and trends for future chlorine sensing development. Due to the increasing use of chlorine in disinfection and chemical synthesis, we believe the information present in this review is a relevant and timely resource for the water treatment industry, healthcare sector, and environmental organizations.


Subject(s)
COVID-19 , Disinfectants , Water Purification , Bacteria , COVID-19/epidemiology , Chlorides , Chlorine , Disinfection/methods , Halogenation , Humans , Pandemics , Reproducibility of Results , Water Purification/methods
2.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327136

ABSTRACT

The widespread SARS-CoV-2 in humans results in the continuous emergence of new variants. Recently emerged Omicron variant with multiple spike mutations sharply increases the risk of breakthrough infection or reinfection, highlighting the urgent need for new vaccines with broad-spectrum antigenic coverage. Using inter-lineage chimera and mutation patch strategies, we engineered a recombinant monomeric spike variant (STFK1628x), which showed high immunogenicity and mutually complementary antigenicity to its prototypic form (STFK). In hamsters, a bivalent vaccine comprised of STFK and STFK1628x elicited high titers of broad-spectrum antibodies to neutralize all 14 circulating SARS-CoV-2 variants, including Omicron;and fully protected vaccinees from intranasal SARS-CoV-2 challenges of either the ancestral strain or immune-evasive Beta variant. Strikingly, the vaccination of hamsters with the bivalent vaccine completely blocked the within-cage virus transmission to unvaccinated sentinels, for either the ancestral SARS-CoV-2 or Beta variant. Thus, our study provides new insights and antigen candidates for developing next-generation COVID-19 vaccines.

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325353

ABSTRACT

Online education is a hot topic that is widely concerned in various countries today. In the era of mobile internet, countries around the world have made various effective attempts at online education, but online education is more of a supplement to school education, and large-scale normal online education lacks cases. The “School’s Out, But Class’s On” campaign launched by the Chinese government during the COVID-19 epidemic created a large-scale, normal online education application. We analyzed the background of this large-scale online education, clarify the foundation of large-scale online education, and reveal the impact of the largest online education activities on society and education.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-324812

ABSTRACT

Background: The pandemic of SARS-CoV-2 has turned into a global public health crisis. Acute SARS-CoV-2 infection is associated with severe pneumonia, multiple-organ failures and deaths. Currently, treatment for SARS-CoV-2 infection and severe pneumonia is largely lacking. Several clinical trials demonstrated that glucocorticoid dexamethasone is effective to reduce disease severity and mortality. However, whether dexamethasone is clinically sufficient to treat COVID-19 is unknown.Methods: We tested the therapeutic effect of dexamethasone on SARS-CoV-2 infection and pneumonia in a Syrian hamster model. Survival rate, body weight loss, viral RNA, antibody responses, severity of lung inflammation and injury were measured in a 7-day acute infection course.Findings: Dexamethasone reduces body weight loss and relieves the diffusion of lung injury in SARS-CoV-2-infected hamster by inhibiting the excessive proinflammatory cytokines including IL-4, IL-6, IL-10, IL-13, TNF-α and IFN-γ. Dexamethasone rescues hamsters from the lethal infection of SARS-CoV-2 variant D614G. Dexamethasone attenuates serum neutralizing antibody and RBD-specific antibody titers, and slightly increases viral RNA level in lung tissues.Interpretation: Overall, using the hamster model, this study improves our understanding of the therapeutic mechanisms and drawbacks of dexamethasone treatment of COVID-19, and suggests that an antiviral is needed to accompany the dexamethasone treatment regimen.Funding: National Science Key Research and Development Project of China, National Natural Science Foundation of China, the CAMS Innovation Fund for Medical Sciences and China Postdoctoral Science Foundation.Declaration of Interest: The authors declare no competing interests.Ethical Approval: All the animal experiments were approved by the Medical Ethics Committee(SUCM2021-112).

5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-316978

ABSTRACT

The COVID-19 pandemic has had and continues to have major impacts on planned and ongoing clinical trials. Its effects on trial data create multiple potential statistical issues. The scale of impact is unprecedented, but when viewed individually, many of the issues are well defined and feasible to address. A number of strategies and recommendations are put forward to assess and address issues related to estimands, missing data, validity and modifications of statistical analysis methods, need for additional analyses, ability to meet objectives and overall trial interpretability.

8.
Environ Int ; 158: 106979, 2022 01.
Article in English | MEDLINE | ID: covidwho-1517151

ABSTRACT

Ambient concentrations of volatile organic compounds (VOCs) vary with emission rates, meteorology, and chemistry. Conventional positive matrix factorization (PMF) loses information because of dilution variations and chemical losses. Multiply improved PMF incorporates the ventilation coefficient, and total solar radiation or oxidants to reduce the effects of dispersion and chemical loss. These methods were applied to hourly speciated VOC data from November 2019 to March 2020 including during the COVID-19 shutdown. Various comparisons were made to assess the influences of these fluctuation drivers by time of day. Dispersion normalized PMF (DN-PMF) reduced the dispersion variations. Dispersion-radiation normalized PMF (DRN-PMF) reduced the impact of chemical loss, especially at night, which was better than Dispersion-Ox normalized PMF (DON-PMF). The conditional bivariate probability function (CBPF) plots of DRN-PMF results were consist with actual source locations. The DN-PMF, DRN-PMF, and DON-PMF results were consistent between 10:00 and 15:00, suggesting dispersion was significantly more influential than photochemical reactions during these times. The DRN-PMF results indicated that the highest VOC contributors during the COVID-19 shutdown were liquefied petroleum gas (LPG) (28.8%), natural gas (25.2%), and pulverized coal boilers emissions (19.6%). Except for petrochemical-related enterprises and LPG, the contribution concentrations of all other sources decreased substantially during the COVID-19 shutdown, by 94.7%, 90.6%, and 86.8% for vehicle emissions, gasoline evaporation, and the mixed source of diesel evaporation and solvent use, respectively. Controlling the use of motor vehicles and related volatilization of diesel fuel and gasoline can be effective in controlling VOCs in the future.


Subject(s)
Air Pollutants , COVID-19 , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Humans , SARS-CoV-2 , Vehicle Emissions/analysis , Volatile Organic Compounds/analysis
9.
Pharmacol Res ; 174: 105955, 2021 12.
Article in English | MEDLINE | ID: covidwho-1487920

ABSTRACT

Severe Coronavirus Disease 2019 (COVID-19) is characterized by numerous complications, complex disease, and high mortality, making its treatment a top priority in the treatment of COVID-19. Integrated traditional Chinese medicine (TCM) and western medicine played an important role in the prevention, treatment, and rehabilitation of COVID-19 during the epidemic. However, currently there are no evidence-based guidelines for the integrated treatment of severe COVID-19 with TCM and western medicine. Therefore, it is important to develop an evidence-based guideline on the treatment of severe COVID-19 with integrated TCM and western medicine, in order to provide clinical guidance and decision basis for healthcare professionals, public health personnel, and scientific researchers involved in the diagnosis, treatment, and care of COVID-19 patients. We developed and completed the guideline by referring to the standardization process of the "WHO handbook for guideline development", the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, and the Reporting Items for Practice Guidelines in Healthcare (RIGHT).


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Drugs, Chinese Herbal/therapeutic use , Infectious Disease Medicine/trends , Medicine, Chinese Traditional/trends , SARS-CoV-2/drug effects , Antiviral Agents/adverse effects , COVID-19/diagnosis , COVID-19/virology , Consensus , Delphi Technique , Drugs, Chinese Herbal/adverse effects , Evidence-Based Medicine/trends , Host-Pathogen Interactions , Humans , Patient Acuity , SARS-CoV-2/pathogenicity , Treatment Outcome
10.
Drug Discov Today ; 27(2): 390-400, 2022 02.
Article in English | MEDLINE | ID: covidwho-1487687

ABSTRACT

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the unprecedented COVID-19 pandemic, which has infected over 178 million people worldwide. Even with new vaccines, global herd immunity will not be reached soon. New cases and viral variants are being reported at an alarming rate. Effective antiviral treatment is urgently needed. Patients with severe COVID-19 suffer from life-threatening respiratory failure due to acute respiratory distress syndrome in their lungs, a leading cause of COVID-19 mortality. This lung hyper-inflammation is induced by virus-caused massive tissue damage that is associated with uncontrolled cytokine release, known as a cytokine storm, through JAK/STAT signaling pathways. Here, we review the FDA-approved JAK inhibitors that are being clinically evaluated and repurposed for the treatment of patients with severe COVID-19 by calming SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/complications , COVID-19/drug therapy , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/etiology , Janus Kinase 2/antagonists & inhibitors , Protein Kinase Inhibitors/therapeutic use , STAT3 Transcription Factor/antagonists & inhibitors , Signal Transduction/drug effects , Animals , Humans
12.
Nat Commun ; 12(1): 4396, 2021 07 20.
Article in English | MEDLINE | ID: covidwho-1387353

ABSTRACT

Rapid development of antisense therapies can enable on-demand responses to new viral pathogens and make personalized medicine for genetic diseases practical. Antisense phosphorodiamidate morpholino oligomers (PMOs) are promising candidates to fill such a role, but their challenging synthesis limits their widespread application. To rapidly prototype potential PMO drug candidates, we report a fully automated flow-based oligonucleotide synthesizer. Our optimized synthesis platform reduces coupling times by up to 22-fold compared to previously reported methods. We demonstrate the power of our automated technology with the synthesis of milligram quantities of three candidate therapeutic PMO sequences for an unserved class of Duchenne muscular dystrophy (DMD). To further test our platform, we synthesize a PMO that targets the genomic mRNA of SARS-CoV-2 and demonstrate its antiviral effects. This platform could find broad application not only in designing new SARS-CoV-2 and DMD antisense therapeutics, but also for rapid development of PMO candidates to treat new and emerging diseases.


Subject(s)
Chemistry Techniques, Synthetic/instrumentation , Chemistry, Pharmaceutical/instrumentation , High-Throughput Screening Assays/instrumentation , Morpholinos/chemical synthesis , Oligonucleotides, Antisense/chemical synthesis , Animals , COVID-19/drug therapy , COVID-19/virology , Chlorocebus aethiops , Communicable Diseases, Emerging/drug therapy , Communicable Diseases, Emerging/microbiology , Disease Models, Animal , High-Throughput Screening Assays/methods , Humans , Morpholinos/pharmacology , Morpholinos/therapeutic use , Muscular Dystrophy, Duchenne/drug therapy , Muscular Dystrophy, Duchenne/genetics , Oligonucleotides, Antisense/pharmacology , Oligonucleotides, Antisense/therapeutic use , Precision Medicine/methods , RNA, Messenger/antagonists & inhibitors , RNA, Viral/antagonists & inhibitors , SARS-CoV-2/genetics , Time Factors , Vero Cells
13.
Front Immunol ; 12: 693579, 2021.
Article in English | MEDLINE | ID: covidwho-1337640

ABSTRACT

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a newly emerging, highly transmitted and pathogenic coronavirus that has caused global public health events and economic crises. As of March 4, 2021, more than 100 million people have been infected, more than 2 million deaths have been reported worldwide, and the numbers are continuing to rise. To date, a specific drug for this lethal virus has not been developed to date, and very little is currently known about the immune evasion mechanisms of SARS-CoV-2. The aim of this review was to summarize and sort dozens of published studies on PubMed to explore the pathogenic features of SARS-CoV-2, as well as the possible immune escape mechanisms of this virus.


Subject(s)
COVID-19/immunology , SARS-CoV-2/physiology , Severe Acute Respiratory Syndrome/immunology , Animals , COVID-19/epidemiology , Host-Pathogen Interactions , Humans , Immune Evasion , Pandemics
14.
Sci Transl Med ; 13(606)2021 08 11.
Article in English | MEDLINE | ID: covidwho-1319371

ABSTRACT

Multiple safe and effective vaccines that elicit immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are necessary to respond to the ongoing coronavirus disease 2019 (COVID-19) pandemic. Here, we developed a protein subunit vaccine composed of spike ectodomain protein (StriFK) plus a nitrogen bisphosphonate-modified zinc-aluminum hybrid adjuvant (FH002C). StriFK-FH002C generated substantially higher neutralizing antibody titers in mice, hamsters, and cynomolgus monkeys than those observed in plasma isolated from COVID-19 convalescent individuals. StriFK-FH002C also induced both TH1- and TH2-polarized helper T cell responses in mice. In hamsters, StriFK-FH002C immunization protected animals against SARS-CoV-2 challenge, as shown by the absence of virus-induced weight loss, fewer symptoms of disease, and reduced lung pathology. Vaccination of hamsters with StriFK-FH002C also reduced within-cage virus transmission to unvaccinated, cohoused hamsters. In summary, StriFK-FH002C represents an effective, protein subunit-based SARS-CoV-2 vaccine candidate.


Subject(s)
COVID-19 , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , Cricetinae , Humans , Mice , Protein Subunits , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics
15.
Nat Metab ; 3(7): 909-922, 2021 07.
Article in English | MEDLINE | ID: covidwho-1279905

ABSTRACT

Exosomes represent a subtype of extracellular vesicle that is released through retrograde transport and fusion of multivesicular bodies with the plasma membrane1. Although no perfect methodologies currently exist for the high-throughput, unbiased isolation of pure plasma exosomes2,3, investigation of exosome-enriched plasma fractions of extracellular vesicles can confer a glimpse into the endocytic pathway on a systems level. Here we conduct high-coverage lipidomics with an emphasis on sterols and oxysterols, and proteomic analyses of exosome-enriched extracellular vesicles (EVs hereafter) from patients at different temporal stages of COVID-19, including the presymptomatic, hyperinflammatory, resolution and convalescent phases. Our study highlights dysregulated raft lipid metabolism that underlies changes in EV lipid membrane anisotropy that alter the exosomal localization of presenilin-1 (PS-1) in the hyperinflammatory phase. We also show in vitro that EVs from different temporal phases trigger distinct metabolic and transcriptional responses in recipient cells, including in alveolar epithelial cells, which denote the primary site of infection, and liver hepatocytes, which represent a distal secondary site. In comparison to the hyperinflammatory phase, EVs from the resolution phase induce opposing effects on eukaryotic translation and Notch signalling. Our results provide insights into cellular lipid metabolism and inter-tissue crosstalk at different stages of COVID-19 and are a resource to increase our understanding of metabolic dysregulation in COVID-19.


Subject(s)
COVID-19/metabolism , COVID-19/virology , Extracellular Vesicles/metabolism , Lipidomics , Metabolomics , SARS-CoV-2 , Biological Transport , COVID-19/epidemiology , Cell Fractionation , Cell Membrane/metabolism , Chemical Fractionation , Cluster Analysis , Computational Biology/methods , Exosomes/metabolism , Host-Pathogen Interactions , Humans , Lipidomics/methods , Metabolome , Metabolomics/methods , Retrospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/immunology
16.
Immunity ; 54(6): 1304-1319.e9, 2021 06 08.
Article in English | MEDLINE | ID: covidwho-1246001

ABSTRACT

Despite mounting evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) engagement with immune cells, most express little, if any, of the canonical receptor of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2). Here, using a myeloid cell receptor-focused ectopic expression screen, we identified several C-type lectins (DC-SIGN, L-SIGN, LSECtin, ASGR1, and CLEC10A) and Tweety family member 2 (TTYH2) as glycan-dependent binding partners of the SARS-CoV-2 spike. Except for TTYH2, these molecules primarily interacted with spike via regions outside of the receptor-binding domain. Single-cell RNA sequencing analysis of pulmonary cells from individuals with coronavirus disease 2019 (COVID-19) indicated predominant expression of these molecules on myeloid cells. Although these receptors do not support active replication of SARS-CoV-2, their engagement with the virus induced robust proinflammatory responses in myeloid cells that correlated with COVID-19 severity. We also generated a bispecific anti-spike nanobody that not only blocked ACE2-mediated infection but also the myeloid receptor-mediated proinflammatory responses. Our findings suggest that SARS-CoV-2-myeloid receptor interactions promote immune hyperactivation, which represents potential targets for COVID-19 therapy.


Subject(s)
COVID-19/metabolism , COVID-19/virology , Host-Pathogen Interactions , Lectins, C-Type/metabolism , Membrane Proteins/metabolism , Myeloid Cells/immunology , Myeloid Cells/metabolism , Neoplasm Proteins/metabolism , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/metabolism , Binding Sites , COVID-19/genetics , Cell Line , Cytokines , Gene Expression Regulation , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Inflammation Mediators/metabolism , Lectins, C-Type/chemistry , Membrane Proteins/chemistry , Models, Molecular , Neoplasm Proteins/chemistry , Protein Binding , Protein Conformation , Single-Domain Antibodies/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Structure-Activity Relationship
17.
Theranostics ; 11(13): 6607-6615, 2021.
Article in English | MEDLINE | ID: covidwho-1231569

ABSTRACT

SARS-CoV-2 infection, which is responsible for the current COVID-19 pandemic, can cause life-threatening pneumonia, respiratory failure and even death. Characterizing SARS-CoV-2 pathogenesis in primary human target cells and tissues is crucial for developing vaccines and therapeutics. However, given the limited access to clinical samples from COVID-19 patients, there is a pressing need for in vitro/in vivo models to investigate authentic SARS-CoV-2 infection in primary human lung cells or tissues with mature structures. The present study was designed to evaluate a humanized mouse model carrying human lung xenografts for SARS-CoV-2 infection in vivo. Methods: Human fetal lung tissue surgically grafted under the dorsal skin of SCID mice were assessed for growth and development after 8 weeks. Following SARS-CoV-2 inoculation into the differentiated lung xenografts, viral replication, cell-type tropism and histopathology of SARS-CoV-2 infection, and local cytokine/chemokine expression were determined over a 6-day period. The effect of IFN-α treatment against SARS-CoV-2 infection was tested in the lung xenografts. Results: Human lung xenografts expanded and developed mature structures closely resembling normal human lung. SARS-CoV-2 replicated and spread efficiently in the lung xenografts with the epithelial cells as the main target, caused severe lung damage, and induced a robust pro-inflammatory response. IFN-α treatment effectively inhibited SARS-CoV-2 replication in the lung xenografts. Conclusions: These data support the human lung xenograft mouse model as a useful and biological relevant tool that should facilitate studies on the pathogenesis of SARS-CoV-2 lung infection and the evaluation of potential antiviral therapies.


Subject(s)
COVID-19/immunology , Disease Models, Animal , Lung/pathology , Respiratory Mucosa/cytology , SARS-CoV-2/immunology , Aborted Fetus , Animals , COVID-19/pathology , COVID-19/virology , Cells, Cultured , Epithelial Cells/virology , Heterografts , Humans , Lung/immunology , Lung/virology , Lung Transplantation , Male , Mice , Mice, SCID , Primary Cell Culture , SARS-CoV-2/pathogenicity , Virus Replication
18.
Signal Transduct Target Ther ; 6(1): 136, 2021 03 31.
Article in English | MEDLINE | ID: covidwho-1164823

ABSTRACT

Epidemiological studies of the COVID-19 patients have suggested the male bias in outcomes of lung illness. To experimentally demonstrate the epidemiological results, we performed animal studies to infect male and female Syrian hamsters with SARS-CoV-2. Remarkably, high viral titer in nasal washings was detectable in male hamsters who presented symptoms of weight loss, weakness, piloerection, hunched back and abdominal respiration, as well as severe pneumonia, pulmonary edema, consolidation, and fibrosis. In contrast with the males, the female hamsters showed much lower shedding viral titers, moderate symptoms, and relatively mild lung pathogenesis. The obvious differences in the susceptibility to SARS-CoV-2 and severity of lung pathogenesis between male and female hamsters provided experimental evidence that SARS-CoV-2 infection and the severity of COVID-19 are associated with gender.


Subject(s)
COVID-19 , SARS-CoV-2/metabolism , Sex Characteristics , Animals , COVID-19/metabolism , COVID-19/pathology , Disease Models, Animal , Disease Susceptibility , Female , Male , Mesocricetus
19.
J Appl Lab Med ; 6(2): 421-428, 2021 03 01.
Article in English | MEDLINE | ID: covidwho-1120035

ABSTRACT

BACKGROUND: Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription PCR is the primary method to diagnose coronavirus disease 2019 (COVID-19). However, the analytic sensitivity required is not well defined and it is unclear how available assays compare. METHODS: For the Abbott RealTime SARS-CoV-2 assay (m2000; Abbott Molecular), we determined that it could detect viral concentrations as low as 26 copies/mL, we defined the relationship between cycle number and viral concentrations, and we tested naso- and oropharyngeal swab specimens from 8538 consecutive individuals. Using the m2000 as a reference assay method, we described the distribution of viral concentrations in these patients. We then used selected clinical specimens to determine the positive percent agreement of 2 other assays with more rapid turnaround times [Cepheid Xpert Xpress (GeneXpert; Cepheid); n = 27] and a laboratory developed test on the Luminex ARIES system [ARIES LDT (Luminex); n = 50] as a function of virus concentrations, from which we projected their false-negative rates in our patient population. RESULTS: SARS-CoV-2 was detected in 27% (95% CI: 26%-28%) of all specimens. Estimated viral concentrations were widely distributed, and 17% (95% CI: 16%-19%) of positive individuals had viral concentrations <845 copies/mL. Positive percent agreement was strongly related to viral concentration, and reliable detection (i.e., ≥95%) was observed at concentrations >100 copies/mL for the GeneXpert but not the ARIES LDT, corresponding to projected false-negative rates of 4% (95% CI: 0%-21%) and 27% (95% CI: 11%-46%), respectively. CONCLUSIONS: Substantial proportions of clinical specimens have low to moderate viral concentrations and may be missed by methods with less analytic sensitivity.


Subject(s)
COVID-19 Nucleic Acid Testing/instrumentation , COVID-19/diagnosis , Reagent Kits, Diagnostic , Real-Time Polymerase Chain Reaction/instrumentation , SARS-CoV-2/isolation & purification , Adult , Aged , Aged, 80 and over , COVID-19/virology , False Negative Reactions , Female , Humans , Limit of Detection , Male , Middle Aged , RNA, Viral/isolation & purification , Reproducibility of Results , Retrospective Studies , SARS-CoV-2/genetics
20.
Energy ; : 119946, 2021.
Article in English | ScienceDirect | ID: covidwho-1046467

ABSTRACT

Better understanding the carbon market can instruct further reforms to perfect its functionality, market efficiency is a key indicator to uncover its current performance. Previous studies have revealed foregone carbon market efficiency;however, given the dynamics of market, it merits the significance to track the up-to-date status. This paper specifically studies the Hubei pilot carbon market, which is quite representative considering its market scale as well as the COVID-19 pandemic context. Wild bootstrapping Variance Ratio test is implemented to detect the market efficiency with the most recent and abundant data. Results show that the market efficiency in the period of 2014 to 2020 is around 0.3951, less than 1, suggesting the weak form efficiency. Observing from sub-sample periods, the efficiency volatiles: climbed from 0.3621 to 0.4027, but drop to 0.3985 finally. Furthermore, the market efficiency soaring after the COVID-19, which echoes the smooth reopening and local supporting policies. To some extent, this study enlarged the impact study of COVID-19, which should be meaningful for further research. Unique contribution of this paper is providing latest evidence for the efficiency of China’s pilot carbon market, as well as proofs for soaring market efficiency after the pandemic.

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