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1.
Journal of Operations Management ; 69(3):404-425, 2023.
Article in English | ProQuest Central | ID: covidwho-2293263

ABSTRACT

This study investigates the impact of the Chinese government's Level I emergency response policy on manufacturers' stock market values. We empirically examine the roles of human resource dependence (labor intensity) and operational slack within the context of supply chain resilience. Through an event study of 1357 Chinese manufacturing companies, we find that the government's emergency response policy triggered statistically significant positive abnormal returns for manufacturers. However, we also find that there exists a negative impact on abnormal returns for manufacturers that are labor‐intensive, giving rise to arguments based in resource dependence theory. In addition, the results indicate the positive role played by operational slack (e.g., financial and inventory slack) in helping manufacturers maintain operations and business continuity, effectively mitigating risks and adding to the manufacturers' resilience. With these findings, we contribute to operations and supply chain management by calling attention to the importance of human resource redundancy while at the same time identifying financial slack and inventory as supply chain resilience strategies that were able to mitigate pandemic‐related risks.

2.
International Journal of Logistics ; 26(2):172-189, 2023.
Article in English | ProQuest Central | ID: covidwho-2286228

ABSTRACT

This paper makes an initial attempt to develop a theory of supply chain resilience through ambidexterity in the context of the COVID-19 pandemic. We conducted a single-case analysis focusing on Zong-Teng Group, one of the biggest cross-border e-commerce enterprises in China, as our sample. Data were mainly collected from interviews with Zong-Teng managers and public online resources. Through case analysis, this paper identifies that a fit between the information processing requirements of a firm and its information processing capability leads to greater ambidexterity for exploitation and exploration, which in turn improves supply chain resilience (SCR) in the form of agility, redundancy and flexibility. In addition, ambidexterity in terms of morality improves SCR culture. This paper may be the first to adopt information processing theory to examine SCR and consider the role of ambidexterity, noting that crises such as COVID-19 impose an exponential increase in information processing requirements, to which many firms fail to respond effectively.

3.
Pathog Immun ; 7(2): 143-170, 2022.
Article in English | MEDLINE | ID: covidwho-2261325

ABSTRACT

Introduction: Neutralizing antibodies have been shown to develop rapidly following SARS-CoV-2 infection, specifically against spike (S) protein, where cytokine release and production is understood to drive the humoral immune response during acute infection. Thus, we evaluated the quantity and function of antibodies across disease severities and analyzed the associated inflammatory and coagulation pathways to identify acute markers that correlate with antibody response following infection. Methods: Blood samples were collected from patients at time of diagnostic SARS-CoV-2 PCR testing between March 2020-November 2020. Plasma samples were analyzed using the MesoScale Discovery (MSD) Platform using the COVID-19 Serology Kit and U-Plex 8 analyte multiplex plate to measure anti-alpha and beta coronavirus antibody concentration and ACE2 blocking function, as well as plasma cytokines. Results: A total of 230 (181 unique patients) samples were analyzed across the 5 COVID-19 disease severities. We found that antibody quantity directly correlated with functional ability to block virus binding to membrane-bound ACE2, where a lower SARS-CoV-2 anti-spike/anti-RBD response corresponded with a lower antibody blocking potential compared to higher antibody response (anti-S1 r = 0.884, P < 0.001; anti-RBD r = 0.75, P < 0.001). Across all the soluble proinflammatory markers we examined, ICAM, IL-1ß, IL-4, IL-6, TNFα, and Syndecan showed a statistically significant positive correlation between cytokine or epithelial marker and antibody quantity regardless of COVID-19 disease severity. Analysis of autoantibodies against type 1 interferon was not shown to be statistically significant between disease severity groups. Conclusion: Previous studies have shown that proinflammatory markers, including IL-6, IL-8, IL-1ß, and TNFα, are significant predictors of COVID-19 disease severity, regardless of demographics or comorbidities. Our study demonstrated that not only are these proinflammatory markers, as well as IL-4, ICAM, and Syndecan, correlative of disease severity, they are also correlative of antibody quantity and quality following SARS-CoV-2 exposure.

4.
Vaccine ; 41(4): 879-882, 2023 Jan 23.
Article in English | MEDLINE | ID: covidwho-2165929

ABSTRACT

It has been demonstrated that after two doses, SARS-CoV-2 mRNA vaccine-induced neutralizing antibodies against Omicron subvariants are much lower than against wild type virus and a booster dose greatly increases Omicron neutralization. We compared Spike-binding IgG responses against wild type virus and four SARS-CoV-2 Omicron subvariants in infection-naïve and previously-infected (hybrid immunity) individuals after the second and the third (booster) dose of BNT162b2. In both groups of individuals, antibodies for all four Omicron subvariants were lower than wild type antibodies. Compared to infection-naïve individuals, hybrid immunity resulted in higher antibodies levels after 2 doses of vaccine but not after the booster. In both groups, antibodies for wild type and all Omicron subvariants waned over an 8-month period post second dose but rebounded after the booster. These results underscore the importance of boosters to restore diminishing antibody levels for both infection-naïve and previously-infected individuals.


Subject(s)
BNT162 Vaccine , COVID-19 , Humans , COVID-19 Vaccines , SARS-CoV-2 , COVID-19/prevention & control , Antibodies, Neutralizing , Antibodies, Viral
5.
Vaccines (Basel) ; 10(11)2022 Nov 11.
Article in English | MEDLINE | ID: covidwho-2110300

ABSTRACT

In vaccine clinical trials, both binding antibody (bAb) levels and neutralization antibody (nAb) titers have been shown to be correlates of SARS-CoV-2 vaccine efficacy. We report a strong correlation bAb and nAb responses against the SARS-CoV-2 Omicron (BA.1) variant in infection-naïve and previously infected (convalescent) individuals after one and two doses of BNT162b2 vaccination. The vaccine-induced bAb levels against Omicron were significantly lower compared to previous variants of concern in both infection-naive and convalescent individuals, with the convalescent individuals showing significantly higher bAb compared to the naïve individuals at all timepoints. The finding that bAb highly correlated with nAb provides evidence for utilizing binding antibody assays as a surrogate for neutralizing antibody assays. Our data also revealed that after full vaccination, a higher percentage of individuals had undetectable Omicron nAb (58.6% in naive individuals, 7.4% in convalescent individuals) compared to the percentage of individuals who had negative Omicron bAb (0% in naive individuals, 0% in convalescent individuals). The discordance between bAb and nAb activities and the high degree of immune escape by Omicron may explain the high frequency of Omicron infections after vaccination.

6.
J Infect Dis ; 226(8): 1407-1411, 2022 10 17.
Article in English | MEDLINE | ID: covidwho-2077783

ABSTRACT

Previous reports demonstrated that severe acute respiratory syndrome coronavirus (SARS-CoV-2) binding immunoglobulin G levels did not increase significantly between the first and second doses of the BNT162b2 vaccine in previously infected individuals. We tested neutralizing antibodies (nAbs) against SARS-CoV-2 Delta and Omicron variants after the first and second doses of this vaccine in infection-naive and previously infected individuals. Delta, but not Omicron, nAb titers significantly increased from the first to the second dose in both groups of individuals. Importantly, we found that Omicron nAb titers were much lower than Delta nAb titers and that even after 2 doses of vaccine, 17 of 29 individuals in the infection-naive group and 2 of 27 in the previously infected group did not have detectable Omicron nAb titers. Infection history alone did not adequately predict whether a second dose resulted in adequate nAb. For future variants of concern, the discussion on the optimal number of vaccine doses should be based on studies testing for nAb against the specific variant.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , Humans , Immunoglobulin G , Neutralization Tests , SARS-CoV-2
7.
Sustainability ; 13(21):11820, 2021.
Article in English | ProQuest Central | ID: covidwho-1512605

ABSTRACT

E-commerce is gaining traction in academia, industry, and with policymakers. Along with this development, the intersection of supply chain management and e-commerce research has become increasingly important. This study explored Osell, a cross-border e-commerce company in China, through a resource orchestration perspective to understand how supply chain resources are deployed to create value in a supply chain service-based business model. We investigated and analysed Osell’s business model based on primary data collected from senior executives and managers, as well as secondary data such as online public resources, and found that the structuring and bundling of resources can be leveraged to enhance service capabilities, which in turn creates value, contributing to supply chain service-based business models with regard to trust improvement, risk mitigation, and consumer satisfaction. This study contributes to the supply chain service-based business model through propositions that have been developed regarding cross-border e-commerce.

8.
J Sep Sci ; 45(2): 456-467, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1499288

ABSTRACT

Chloroquine and hydroxychloroquine have been studied since the early clinical treatment of SARS-CoV-2 outbreak. Considering these two chiral drugs are currently in use as the racemate, high-expression angiotensin-converting enzyme 2 cell membrane chromatography was established for investigating the differences of two paired enantiomers binding to angiotensin-converting enzyme 2 receptor. Molecular docking assay and detection of SARS-CoV-2 spike pseudotyped virus entry into angiotensin-converting enzyme 2-HEK293T cells were also conducted for further investigation. Results showed that each single enantiomer could bind well to angiotensin-converting enzyme 2, but there were differences between the paired enantiomers and corresponding racemate in frontal analysis. R-Chloroquine showed better angiotensin-converting enzyme 2 receptor binding ability compared to S-chloroquine/chloroquine (racemate). S-Hydroxychloroquine showed better angiotensin-converting enzyme 2 receptor binding ability than R-hydroxychloroquine/hydroxychloroquine. Moreover, each single enantiomer was proved effective compared with the control group; compared with S-chloroquine or the racemate, R-chloroquine showed better inhibitory effects at the same concentration. As for hydroxychloroquine, R-hydroxychloroquine showed better inhibitory effects than S-hydroxychloroquine, but it slightly worse than the racemate. In conclusion, R-chloroquine showed better angiotensin-converting enzyme 2 receptor binding ability and inhibitory effects compared to S-chloroquine/chloroquine (racemate). S-Hydroxychloroquine showed better angiotensin-converting enzyme 2 receptor binding ability than R-hydroxychloroquine/hydroxychloroquine (racemate), while the effect of preventing SARS-CoV-2 pseudovirus from entering cells was weaker than R-hydroxychloroquine/hydroxychloroquine (racemate).


Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/drug effects , Chloroquine/chemistry , Chloroquine/pharmacology , Chromatography, High Pressure Liquid/methods , Hydroxychloroquine/chemistry , Hydroxychloroquine/pharmacology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , COVID-19/virology , Cell Membrane/chemistry , Cell Membrane/drug effects , Cell Membrane/virology , HEK293 Cells , Humans , In Vitro Techniques , Molecular Docking Simulation , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/chemistry , Receptors, Virus/drug effects , SARS-CoV-2/chemistry , SARS-CoV-2/drug effects , Solvents , Stereoisomerism , Viral Pseudotyping , Virus Internalization , COVID-19 Drug Treatment
9.
Kidney Med ; 3(4): 653-658, 2021.
Article in English | MEDLINE | ID: covidwho-1213576

ABSTRACT

Recent case reports suggest that coronavirus disease 2019 (COVID-19) is associated with collapsing glomerulopathy in African Americans with apolipoprotein L1 gene (APOL1) risk alleles; however, it is unclear whether disease pathogenesis is similar to HIV-associated nephropathy. RNA sequencing analysis of a kidney biopsy specimen from a patient with COVID-19-associated collapsing glomerulopathy and APOL1 risk alleles (G1/G1) revealed similar levels of APOL1 and angiotensin-converting enzyme 2 (ACE2) messenger RNA transcripts as compared with 12 control kidney samples downloaded from the GTEx (Genotype-Tissue Expression) Portal. Whole-genome sequencing of the COVID-19-associated collapsing glomerulopathy kidney sample identified 4 indel gene variants, 3 of which are of unknown significance with respect to chronic kidney disease and/or focal segmental glomerulosclerosis. Molecular profiling of the kidney demonstrated activation of COVID-19-associated cell injury pathways such as inflammation and coagulation. Evidence for direct severe acute respiratory syndrome coronavirus 2 infection of kidney cells was lacking, which is consistent with the findings of several recent studies. Interestingly, immunostaining of kidney biopsy sections revealed increased expression of phospho-STAT3 (signal transducer and activator of transcription 3) in both COVID-19-associated collapsing glomerulopathy and HIV-associated nephropathy as compared with control kidney tissue. Importantly, interleukin 6-induced activation of STAT3 may be a targetable mechanism driving COVID-19-associated acute kidney injury.

10.
Gastronomica ; 21(1):77, 2021.
Article in English | ProQuest Central | ID: covidwho-1197412

ABSTRACT

As the coronavirus emerged as a global pandemic during early 2020, "ground zero" of the disease was initially named in the press as the Huanan Seafood Wholesale Market in the city of Wuhan, Hubei, in central China. With a population of over 11 million residents, and as a major transportation hub situated on the Yangtze River, Wuhan was placed under strict lockdown at the end of January by Chinese authorities, with severe restrictions on travel and movement. These efforts at containment proved too late to prevent the eventual spread of the virus around the world. The dramatic global impact of the virus has been all too painfully clear, yet the exact origins and zoonotic transmission pathway of the virus remain uncertain. Scientists suggest that SARS-CoV-2 probably jumped from horseshoe bats to an unknown intermediate animal vector, from which it spread to humans, but exactly how, where, and when this happened is still unknown..

12.
Anal Bioanal Chem ; 413(11): 2995-3004, 2021 May.
Article in English | MEDLINE | ID: covidwho-1092079

ABSTRACT

Traditional Chinese medicines played an important role in the treatment of COVID-19 in 2020. Ephedra sinica, one of the major constituent herbs of multi-component herbal formula, has been widely used to treat COVID-19 in China. However, its active components are still unclear. The objectives of this study are to screen and evaluate active components from the traditional Chinese medicine Ephedra sinica for the treatment of COVID-19. In our study, we established an ACE2/CMC bioaffinity chromatography model, and then developed an ACE2/CMC-HPLC-IT-TOF-MS system for the active compounds screening and identification from Ephedra sinica extract. We performed molecular docking and surface plasmon resonance (SPR) assays to assess the binding characteristics (binding mode and KD value). We used CCK-8 staining to assess the toxicity of screened compounds, and also used SARS-CoV-2 pseudovirus to observe the viropexis effect of screened compounds in ACE2h cells. In this current work, one fraction was fished out, separated and identified as ephedrine (EP), pseudoephedrine (PEP), and methylephedrine (MEP). Binding assays showed that the three compounds could bind with ACE2 in a special way to some amino acid residues, similar to the way SARS-CoV-2 bound with ACE2. Additionally, the three compounds, especially EP, can inhibit the entrance of SARS-CoV-2 spike pseudovirus into ACE2h cells because they can reduce the entrance ratio of pseudovirus in the pseudovirus model. Overall, the ACE2/CMC-HPLC-IT-TOF-MS system was established and verified to be suitable for ACE2-targeted bioactive compound screening. EP, PEP, and MEP with ACE2-binding features were screened out from Ephedra sinica, and acted as blockers inhibiting SARS-CoV-2 spike pseudovirus entering ACE2h cells.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , COVID-19 Drug Treatment , Drugs, Chinese Herbal/pharmacology , Ephedra sinica , SARS-CoV-2/drug effects , Antiviral Agents/chemistry , Antiviral Agents/isolation & purification , COVID-19/metabolism , China , Chromatography, High Pressure Liquid , Drug Discovery , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/isolation & purification , Ephedra sinica/chemistry , Ephedrine/analogs & derivatives , Ephedrine/isolation & purification , Ephedrine/pharmacology , HEK293 Cells , Humans , Mass Spectrometry , Molecular Docking Simulation , SARS-CoV-2/physiology , Virus Internalization/drug effects
13.
J Zhejiang Univ Sci B ; 21(12): 948-954, 2020.
Article in English | MEDLINE | ID: covidwho-999886

ABSTRACT

The aim of this study was to evaluate the safety of an antiviral regimen of protease inhibitors combined with Arbidol (umifenovir) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia patients. The genomic sequence of SARS-CoV-2 is highly homologous to that of SARS-CoV (Zhou et al., 2020). Previously published basic and clinical research on anti-SARS-CoV treatment found that lopinavir/ritonavir (LPV/r) could improve the prognosis of SARS patients (Chan et al., 2003; Chu et al., 2004). Darunavir (DRV) is another protease inhibitor that blocks the binding of SARS-CoV-2 to human angiotensin-converting enzyme 2 (Omotuyi et al., 2020). The broad-spectrum antiviral drug Arbidol (umifenovir) also shows in vitro anti-SARS-CoV activity (Khamitov et al., 2008).


Subject(s)
COVID-19 Drug Treatment , Indoles/therapeutic use , Protease Inhibitors/therapeutic use , Adult , China , Darunavir , Drug Combinations , Female , Humans , Indoles/adverse effects , Lipid Metabolism , Lopinavir , Male , Middle Aged , Protease Inhibitors/adverse effects , Retrospective Studies , Ritonavir , SARS-CoV-2/drug effects , SARS-CoV-2/genetics
14.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1162: 122469, 2021 Jan 01.
Article in English | MEDLINE | ID: covidwho-947269

ABSTRACT

The recent emergence of the novel pathogenic coronavirus disease 2019 (COVID-19) is responsible for a worldwide pandemic. In sight of this, there has been growing interest in the use of chloroquine (CQ) and hydroxychloroquine (HCQ) as potential treatments. In this study, we use angiotensin converting enzyme 2 (ACE2) over-expressed cell membrane chromatography (CMC) to study the interaction of CQ and HCQ with ACE2 receptor. Both CQ and HCQ were retained on the ACE2/CMC column. Then we analyzed the binding character of CQ and HCQ to ACE2 by CMC frontal analysis, ionic force investigation and competitive binding experiment. Results showed that CQ and HCQ KD values obtained from the CMC frontal analysis method were 8.22(±0.61) × 10-7 M and 11.70(±2.44) × 10-7 M. Compare to CQ, HCQ has the weaker affinity with ACE2. The action force of CQ, HCQ and ACE2 is mainly ionic force. CQ and HCQ have different degrees of competitive binding relationship with ACE2. Our study revealed the interaction of CQ and HCQ with ACE2 receptor, which provides new insights for the use of CQ and HCQ in the treatment of COVID-19. Moreover, this biomimetic drug screening method is expected to open the door for rapid targeting and separating bioactive ingredients active towards ACE2 receptor.


Subject(s)
Angiotensin-Converting Enzyme 2/drug effects , Antimalarials/pharmacology , Cell Membrane/chemistry , Chloroquine/pharmacology , Hydroxychloroquine/pharmacology , Angiotensin-Converting Enzyme 2/biosynthesis , Binding, Competitive/drug effects , COVID-19/metabolism , Chromatography/methods , Humans , Models, Molecular , Molecular Docking Simulation
15.
Phytomedicine ; 79: 153333, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-741456

ABSTRACT

BACKGROUND: The novel coronavirus disease (2019-nCoV) has been affecting global health since the end of 2019 and there is no sign that the epidemic is abating . The major issue for controlling the infectious is lacking efficient prevention and therapeutic approaches. Chloroquine (CQ) and Hydroxychloroquine (HCQ) have been reported to treat the disease, but the underlying mechanism remains controversial. PURPOSE: The objective of this study is to investigate whether CQ and HCQ could be ACE2 blockers and used to inhibit 2019-nCoV virus infection. METHODS: In our study, we used CCK-8 staining, flow cytometry and immunofluorescent staining to evaluate the toxicity and autophagy of CQ and HCQ, respectively, on ACE2 high-expressing HEK293T cells (ACE2h cells). We further analyzed the binding character of CQ and HCQ to ACE2 by molecular docking and surface plasmon resonance (SPR) assays, 2019-nCoV spike pseudotyped virus was also used to observe the viropexis effect of CQ and HCQ in ACE2h cells. RESULTS: Results showed that HCQ is slightly more toxic to ACE2h cells than CQ. Both CQ and HCQ could bind to ACE2 with KD = (7.31 ± 0.62)e-7 M and (4.82 ± 0.87)e-7 M, respectively. They exhibit equivalent suppression effect for the entrance of 2019-nCoV spike pseudotyped virus into ACE2h cells. CONCLUSIONS: CQ and HCQ both inhibit the entrance 2019-nCoV into cells by blocking the binding of the virus with ACE2. Our findings provide novel insights into the molecular mechanism of CQ and HCQ treatment effect on virus infection.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Betacoronavirus/drug effects , Chloroquine/pharmacology , Hydroxychloroquine/pharmacology , Peptidyl-Dipeptidase A/drug effects , Angiotensin-Converting Enzyme 2 , Autophagy/drug effects , Betacoronavirus/physiology , COVID-19 , Coronavirus Infections/drug therapy , HEK293 Cells , Humans , Molecular Docking Simulation , Pandemics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral , SARS-CoV-2 , COVID-19 Drug Treatment
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