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1.
Empirical economics ; : 1-36, 2022.
Article in English | EuropePMC | ID: covidwho-2033755

ABSTRACT

Individual social responsibility is essential to achieving the sustainable development goals of the society, yet there has been very little research on whether and how social and cultural factors influence individual social responsibility. Using the Covid-19 pandemic as our empirical context, this research examines the relationship between social capital and individual social distancing behaviors during the pandemic. Social distancing is a form of socially responsible behavior because it is critical in mitigating the spread of the Covid-19 virus. By exploiting daily mobile GPS location data, we provide strong evidence for the divergent relationships between the two constituents of social capital–civic norms and social networks–and social distancing behaviors. While civic norms are positively associated with social distancing, social networks have a negative association with social distancing. These results are consistent with a nuanced view of social capital: civic norms facilitate cooperation and self-sacrifice for the common good, whereas social networks increase individual embeddedness and hence inertia in maintaining social interactions, resulting in opposite effects on social distancing. Our results contribute to the research at the intersection of social capital and individual social responsibility by highlighting the nuanced effects of social capital on individual responses to the pandemic and provide valuable insights for policymakers and businesses in disaster management.

2.
Preprint in English | medRxiv | ID: ppmedrxiv-22279959

ABSTRACT

While the development of different vaccines has slowed the dissemination of SARS-CoV-2, the occurrence of breakthrough infections continues to fuel the pandemic. As a strategy to secure at least partial protection, with a single dose of a given COVID-19 vaccine to maximum possible fraction of the population, delayed administration of subsequent doses (or boosters) has been implemented in many countries. However, waning immunity and emergence of new variants of SARS-CoV-2 suggest that such measures may jeopardize the attainment of herd immunity due to intermittent lapses in protection. Optimizing vaccine dosing schedules could thus make the difference between periodic occurrence of breakthrough infections or effective control of the pandemic. To this end, we have developed a mechanistic mathematical model of adaptive immune response to vaccines and demonstrated its applicability to COVID-19 mRNA vaccines as a proof-of-concept for future outbreaks. The model was thoroughly calibrated against multiple clinical datasets involving immune response to SARS-CoV-2 infection and mRNA vaccines in healthy and immunocompromised subjects (cancer patients undergoing therapy); the model showed robust clinical validation by accurately predicting neutralizing antibody kinetics, a correlate of vaccine-induced protection, in response to multiple doses of mRNA vaccines. Importantly, we estimated population vulnerability to breakthrough infections and predicted tailored vaccination dosing schedules to maximize protection and thus minimize breakthrough infections, based on the immune status of a sub-population. We have identified a critical waiting window for cancer patients (or, immunocompromised subjects) to allow recovery of the immune system (particularly CD4+ T-cells) for effective differentiation of B-cells to produce neutralizing antibodies and thus achieve optimal vaccine efficacy against variants of concern, especially between the first and second doses. Also, we have obtained optimized dosing schedules for subsequent doses in healthy and immunocompromised subjects, which vary from the CDC-recommended schedules, to minimize breakthrough infections. The developed modeling tool is based on generalized adaptive immune response to antigens and can thus be leveraged to guide vaccine dosing schedules during future outbreaks.

3.
Journal of Physics: Conference Series ; 2194(1):012010, 2022.
Article in English | ProQuest Central | ID: covidwho-1730587

ABSTRACT

Since the end of 2019, the Corona Virus Disease 2019 (COVID-19) pandemic has led to a surge in the use of all kinds of medical supplies, especially surgical masks. Based on the microstructure and anti-virus mechanism of melt-blown materials used for medical masks, this paper introduces the research status of nonwoven filter materials used for protective masks. At the same time, the surface interface structure of four disposable medical protective masks from different manufacturers was analyzed by scanning electron microscope, and the difference of melt-blown materials of these masks was studied. The results show that the fiber diameter of melt-blown mask with better protective effect is fine and compact, and the aperture formed between fibers is smaller. This reasearch provides new ideas for further research and development of non-woven materials for medical masks.

4.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329024

ABSTRACT

Background: Adolescent electronic cigarette (e-cigarette) use is an emerging global public health concern as nicotine addiction may be established among this vulnerable population. Its study has generated a burgeoning body of research charactering a wide spectrum. However, the development and current status of research on this alarming issue have been inadequately examined in an objective, systematic and visualized way. This bibliometric analysis aims to fill this gap by providing a comprehensive overview of scientific literature in relation to adolescent e-cigarette use. Methods A total of 943 eligible papers published from 2011 to 2021 were retrieved from Web of Science Core Collection. Performance analysis was used with various bibliometric indicators to examine the publication trend, most prolific countries, institutions, authors, journals, and highly cited articles. Science mapping based on VOSviewer was employed to visualize the collaboration networks between countries and authors, research hotspots, and their evolutions. Results Publications on adolescent e-cigarette use has increased significantly during the past decade. The USA dominated this field in all aspects and the University of Southern California was the most productive institution. There were clear collaborative author groupings, but their transnational collaborations were generally weak. Major research themes were identified in the extant literature, including epidemiology and KABs;risk factors;health implications;gateway effect;and prevention interventions. The keywords such as ‘vapor’, ‘flavor’, ‘advertising’, ‘dual use’ reflected research emphases in early studies while ‘bullying’, ‘COVID-19’, ‘social norms’ , and ‘heated tobacco products’ were the emerging research trends. Conclusion This study is presumed to provide an overall picture of research on adolescent e-cigarette use, which may help scholars and public health practitioners stay abreast of the research developments and serve as a reference and entry point for further investigation into this multifaceted phenomenon.

5.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-326156

ABSTRACT

Ultraviolet-C light-emitting diodes (UVC-LEDs) have great application in pathogen inactivation under various kinds of situations, especially in the fight against the COVID-19. Unfortunately, its epitaxial wafers are so far limited to 2-inch size, which greatly increases the cost of massive production. In this work, we report the 4-inch crack-free high-power UVC-LED wafer. This achievement relies on a proposed strain-tailored strategy, where a three-dimensional to two-dimensional (3D-2D) transition layer is introduced during the homo-epitaxy of AlN on high temperature annealed (HTA)-AlN template, which successfully drives the original compressive strain into tensile one and thus solves the challenge of realizing high quality Al$_{0.6}$Ga$_{0.4}$N layer with a flat surface. This smooth Al$_{0.6}$Ga$_{0.4}$N layer is nearly pseudomorphically grown on the strain-tailored HTA-AlN template, leading to 4-inch UVC-LED wafers with outstanding performances. Our strategy succeeds in compromising the bottlenecked contradictory in producing large-sized UVC-LED wafer on pronounced crystalline AlN template: The compressive strain in HTA-AlN allows for crack-free 4-inch wafer, but at the same time leads to a deterioration of the AlGaN morphology and crystal quality. The launch of 4-inch wafers makes the chip fabrication process of UVC-LEDs matches the mature blue one, and will definitely speed up the universal of UVC-LED in daily life.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325235

ABSTRACT

Background: To compare the contingency modifications to the dental education between the University of Toronto Faculty of Dentistry and the Zhejiang University School of Stomatology during COVID-19 pandemic, and to share experiences in keeping the dental academic continuity, resuming practicing activities and preparing the faculty and students for a new normality. Three approaches were adopted to collect information and data: online interviews and email-contact with the instructors and the deans, a small-scale online survey of dental students, and official online announcements of various authorities. Results: : The two universities shared similarity in changing trends, while differed in details. The delivery of lectures, seminars and exams was transitioned from in-person mode to online mode and has proceeded effectively and efficiently. The pre-clinical lab training and clinical rotation were the most retarded parts and will not be resumed until the settle-down of the pandemic. Research activities have been kept on at the best possible level. Since the Zhejiang University reopened the campus in May 2020, clinical activities and research works were in recovery with a cautiously-planned and gradual phased approach. Conclusion: Both universities have been trying their best to meet the academic needs of students while protect their health, and to keep alert to the real time epidemic situation in preparation for resumption. Dental institutions could take the COVID-19 pandemic as an opportunity to armor dental students with infection control measures prior to their reengagement into clinical practice. There is a need of a new normality for global dental education that spans time and space.

7.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324180

ABSTRACT

Background: Confronting with the outbreak of COVID-19, this cross-sectional study aimed to assess the differences of psychological status of temporomandibular disorders patients, orthodontic patients and the general population in China during the epidemic. Methods An online anonymous questionnaire was developed in Chinese, including the individual background information, the perception of the epidemic, and level of anxiety and depression through Kessler Psychological Distress Scale (K10). The respondents were divided into Control group, ORTHO group and TMD group. Descriptive analysis and multiple linear regression modelling were performed. Results 1241 valid questionnaires in total were collected, with 587 orthodontic patients and 220 TMD patients. The mean score of K10 was 18.65. When compared with the general population, TMD patients displayed statistically higher level of anxiety and depression (P<0.05), whereas orthodontic patients not (P>0.05). Multiple linear regression model also showed that age, gender, some concerns about the impact of epidemic were correlated with psychological status. Conclusions The overall mental health was severely worsened by the COVID-19 epidemic. TMD patients had higher level of psychological distress than orthodontic patients and the general population. Factors such as younger age, female, concerning about the isolation and psychological barriers and distrust were amongst the associations with a high level of psychological distress. Mental health care should be paid to patients when hospitals and clinics re-open after the COVID-19 epidemic, especially to patients with these relevant characteristics.

8.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-296307

ABSTRACT

In the search for treatment schemes of COVID-19, we start by examining the general weakness of coronaviruses and then identify approved drugs attacking that weakness. The approach, if successful, should identify drugs with a specific mechanism that is at least as effective as the best drugs proposed and are ready for clinical trials. All coronaviruses translate their non-structural proteins (∼16) in concatenation, resulting in a very large super-protein. Homo-harringtonine (HHT), which has been approved for the treatment of leukemia, blocks protein elongation very effectively. Hence, HHT can repress the replication of many coronaviruses at the nano-molar concentration. In two mouse models, HHT clears SARS-CoV-2 in 3 days, especially by nasal dripping of 40 ug per day. We also use dogs to confirm the safety of HHT delivered by nebulization. The nebulization scheme could be ready for large-scale applications at the onset of the next epidemics. For the current COVID-19, a clinical trial has been approved by the Ditan hospital of Beijing but could not be implemented for want of patients. The protocol is available to qualified medical facilities.

9.
National Bureau of Economic Research Working Paper Series ; No. 28588, 2021.
Article in English | NBER, Grey literature | ID: grc-748267

ABSTRACT

Digital technologies may make some tasks, jobs and firms more resilient to unanticipated shocks. We extract data from over 200 million U.S. job postings to construct an index for firms' resilience to the Covid-19 pandemic by assessing the work-from-home (WFH) feasibility of their labor demand. Using a difference-in-differences framework, we find that public firms with high pre-pandemic WFH index values had significantly higher sales, net incomes, and stock returns than their peers during the pandemic. Our results indicate that firms with higher digital resilience, as measured through our pre-pandemic WFH index, performed significantly better in general, and in non-essential industries in particular, where WFH feasibility was necessary to continue operation. The ability to use digital technologies to work remotely also mattered more in non-high-tech industries than in high-tech ones. Lastly, we find evidence that firms with lower pre-pandemic WFH feasibility attempted to catch up to their more resilient competitors via greater software investment. This is consistent with a complementarity between digital technologies and WFH practices. Our study's results are robust to a variety of empirical specifications and provide a first look at how WFH practices improved resilience to a major, unanticipated social and economic shock.

10.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-291513

ABSTRACT

Background: The long-term impact of COVID-19 on patient health has been a recent focus. This study aims to determine the persistent symptoms and psychological conditions of patients hospitalized with COVID-19 15 months after onset. The potential risk factors were also explored.Methods: A cohort of COVID-19 patients discharged from February 20, 2020 to March 31, 2020 was recruited. Follow-ups were conducted using validated questionnaires and psychological screening scales at 15 months after onset to evaluate the patients’ health status. The risk factors for long-term health impacts and their associations with disease severity was analyzed.Findings: 534 COVID-19 patients were enrolled. The median age of the patients was 62.0 years old (IQR 52.0-70.0) and 295 were female (55.2%). The median time from onset to follow-up was 460.0 (451.0-467.0) days. Sleep disturbance (18.5%, 99/534) and fatigue (17.2%, 92/534) were the most common persistent symptoms. 6.4% (34/534) of the patients had depression, 9.2% (49/534) were anxious, 13.0% (70/534) had insomnia and 4.7% (25/534) suffered from posttraumatic stress disorder (PTSD). Multivariate adjusted logistic regression analysis showed that glucocorticoid use during hospitalization (OR 3.58, 95% CI 1.12-11.44) was significantly associated with an increased risk of fatigue. The OR values for anxiety and sleep disorders were 2.36 (95% CI 1.07-5.20) and 2.16 (95% CI 1.13-4.14) in females compared with males. The OR value of PTSD was 25.6 (95% CI 3.3-198.4) in patients with persistent symptoms to those without persistent symptoms. No significant associations were observed between fatigue syndrome or adverse mental outcomes and disease severity.Interpretation: 15-month follow-up in this study aroused the need of extended rehabilitation intervention for complete recovery in COVID-19 patients. Funding: None to declare. Declaration of Interest: All the authors declare no competing interests.Ethical Approval: The Research Ethics Committee of Shanghai Changzheng Hospital approved this study (2020SL007).

11.
Pharmacological Research - Modern Chinese Medicine ; : 100007, 2021.
Article in English | ScienceDirect | ID: covidwho-1401788

ABSTRACT

Targeted therapeutics for SARS-CoV-2 virus caused COVID-19 are in urgent need. Cinobufacini has been reported to have broad-spectrum antiviral effects and widely used in Southeast Asian countries. This study aims to assess the efficacy of Cinobufacini injection in treating patients with severe COVID-19. A randomized preliminary clinical trial was conducted and eligible patients were allocated to receive general treatment plus Cinobufacini injection or only general treatment as control for 7 days. The primary outcomes of the oxygenation index PaO2/FiO2 and ROX, secondary outcomes of white blood cell count, respiratory support step-down time (RSST), safety indicators, etc were monitored. After 7 days of treatment, the oxygenation index was improved in 95.2% patients in the treatment group compared with 68.4% in the control group. The PaO2/FiO2 and ROX indices in the treatment group (mean, 226.27±67.35 and 14.01±3.99 respectively) were significantly higher than the control group (mean, 143.23±51.29 and 9.64±5.54 respectively). The RSST was 1 day shorter in the treatment group. Multivariate regression analysis suggested that Cinobufacini injection contributed the most to the outcome of PaO2/FiO2. No obvious adverse effects were observed. The preliminary data showed that Cinobufacini injection had apparent efficacy in improving the respiratory function of patients with severe COVID-19.

12.
Mikrochim Acta ; 188(8): 284, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1397013

ABSTRACT

An aptasensor for electrochemical detection of carbendazim is reported with mulberry fruit-like gold nanocrystal (MF-Au)/multiple graphene aerogel (MGA) and DNA cycle amplification. HAuCl4 was reduced by ascorbic acid in a CTAC solution containing KBr and KI and formed trioctahedron gold nanocrystal. The gold nanocrystal underwent structural evolution under enantioselective direction of L-cysteine. The resulting MF-Au shows a mulberry fruit-like nanostructure composed of gold nanocrystals of about 200 nm as the core and many irregular gold nanoparticles of about 30 nm as the shell. The exposure of high-index facets improves the catalytic activity of MF-Au. MF-Au/MGA was used for the construction of an aptasensor for electrochemical detection of carbendazim. The aptamer hybridizes with assistant strand DNA to form duplex DNA. Carbendazim binds with the formed duplex DNA to release assistant strand DNA, triggering one three-cascade DNA cycle. The utilization of a DNA cycle allows one carbendazim molecule to bring many methylene blue-labeled DNA fragments to the electrode surface. This promotes significant signal amplification due to the redox reaction of methylene blue. The detection signal is further enhanced by the catalysis of MF-Au and MGA towards the redox of methylene blue. A differential pulse voltammetric signal, best measured at - 0.32 V vs. Ag/AgCl, increases linearly with the carbendazim concentration ranging from 1.0 × 10-16 to 1.0 × 10-11 M with a detection limit of 4.4 × 10-17 M. The method provides ultrahigh sensitivity and selectivity and was successfully applied to the electrochemical detection of carbendazim in cucumber. This study reports on an ultrasensitive aptasensor for electrochemical detection of carbendazim in cucumber based on mulberry fruit-like gold nanocrystal-multiple graphene aerogel and DNA cycle double amplification.


Subject(s)
Aptamers, Nucleotide/chemistry , Benzimidazoles/analysis , Biosensing Techniques/methods , Carbamates/analysis , DNA/chemistry , Metal Nanoparticles/chemistry , Benzimidazoles/chemistry , Carbamates/chemistry , Cysteine/chemistry , Electrochemical Techniques/methods , Gels/chemistry , Gold/chemistry , Graphite/chemistry , Immobilized Nucleic Acids/chemistry , Limit of Detection , Methylene Blue/chemistry , Oxidation-Reduction
13.
Chinese Journal of Contemporary Pediatrics ; 22(3):211-214, 2020.
Article in English | PMC | ID: covidwho-1389761

ABSTRACT

Since December 2019, the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has occurred in Wuhan, Hubei Province, China. The infected cases were noted mostly in adults, but rarely reported in children, especially neonates. Most children with SARS-CoV-2 infection present mainly with respiratory symptoms, but less commonly with gastrointestinal symptoms, and tend to have mild clinical symptoms. A neonate with SARS-CoV-2 infection, who had vomiting and milk refusal as the first symptom, was recently admitted to Wuhan Children's Hospital. After two weeks of treatment, the patient recovered gradually and was discharged. Here, this case is reported to improve the understanding of SARS-CoV-2 infection in neonates.

15.
Disease Surveillance ; 36(2):127-130, 2021.
Article in Chinese | GIM | ID: covidwho-1229332

ABSTRACT

Objective: To understand the epidemiological characteristics of an outbreak of coronavirus disease 2019 (COVID-19) in Dalian, Liaoning, July-August, 2020, and provide reference for the prevention and control of COVID-19.

17.
SciFinder; 2020.
Preprint | SciFinder | ID: ppcovidwho-4197

ABSTRACT

A review. Since Dec. 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has out-broken and spread rapidly in Wuhan, Hubei, nationwide, and even other countries, with clustering cases. Clin. manifestations include fever, fatigue, dry cough, and difficulty breathing. with or without upper respiratory tract symptoms such as nasal congestion and runny nose. There is no evidence from randomized controlled trial to support the treatment of new anti- severe acute respiratory syndrome coronavirus 2 suspected or confirmed cases, and there is an urgent need to better understand this new virus and develop drugs to treat.

19.
Molecules (Basel) ; 25(13), 2020.
Article in English | MEDLINE | ID: covidwho-662251

ABSTRACT

Surface charge accumulation on epoxy insulators is one of the most serious problems threatening the operation safety of the direct current gas-insulated transmission line (GIL), and can be efficiently inhibited by the surface modification technology. This paper investigated the mechanisms of fluorination modulated surface charge behaviors of epoxy resin through quantum chemical calculation (QCC) analysis of the molecular structure. The results show that after fluorination, the surface charge dissipation process of the epoxy sample is accelerated by the introduced shallow trap sites, which is further clarified by the carrier mobility model. The electron distribution probability of the highest occupied molecular orbitals (HOMO) under positive charging and the lowest unoccupied molecular orbitals (LUMO) under negative charging shows distinctive patterns. It is illustrated that electrons are likely to aggregate locally around benzenes for the positively charged molecular structure, while electrons tend to distribute all along the epoxy chain under negatively charging. The calculated results verify that fluorination can modulate surface charge behaviors of epoxy resin through redesigning its molecular structure, trap distribution and charging patterns.

20.
Preprint in English | medRxiv | ID: ppmedrxiv-20119735

ABSTRACT

High Ct-values falling in the grey zone are frequently encountered in SARS-CoV-2 detection by real-time reverse transcription PCR (rRT-PCR) and have brought urgent challenges in diagnosis of samples with low viral load. Based on the single-stranded DNA reporter trans-cleavage activity by Cas12a upon target DNA recognition, we create a Specific Enhancer for detection of PCR-amplified Nucleic Acids (SENA) to confirm SARS-CoV-2 detection through specifically targeting its rRT-PCR amplicons. SENA is highly sensitive, with its limit of detection being at least 2 copies/reaction lower than that of the corresponding rRT-PCR, and highly specific, which identifies both false-negative and false-positive cases in clinic applications. SENA provides effective confirmation for nucleic acid amplification-based molecular diagnosis, and may immediately eliminate the uncertainty problems of rRT-PCR in SARS-CoV-2 clinic detection. One Sentence SummaryCRISPR-Cas12a-based COVID-19 diagnosis.

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