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1.
Indian Journal of Pharmaceutical Sciences ; 84(3):617-630, 2022.
Article in English | EMBASE | ID: covidwho-1957666

ABSTRACT

Drug repositioning may be a promising way to find potential therapies against coronavirus disease 2019. Although chloroquine and hydroxychloroquine showed controversial results against the coronavirus disease 2019 disease, the potential common and diverging mechanisms of action are not reported and need to be dissected for better understanding them. An integrated strategy was proposed to systematically decipher the common and diverging aspects of mechanism of chloroquine and hydroxychloroquine against coronavirus disease 2019-disease network based on network pharmacology and in silico molecular docking. Potential targets of the two drugs and coronavirus disease 2019 related genes were collected from online public databases. Target function enrichment analysis, tissue enrichment maps and molecular docking analysis were carried out to facilitate the systematic understanding of common and diverging mechanisms of the two drugs. Our results showed that 51 chloroquine targets and 47 hydroxychloroquine targets were associated with coronavirus disease 2019. The core targets include tumor necrosis factor, glyceraldehyde 3-phosphate dehydrogenase, lymphocyte-specific protein-tyrosine kinase, beta-2 microglobulin, nuclear receptor coactivator 1, peroxisome proliferator-activated receptor gamma and glutathione disulfide reductase. Both chloroquine and hydroxychloroquine had good binding affinity towards tumor necrosis factor (affinity=-8.6 and -8.4 kcal/mol, respectively) and glyceraldehyde 3-phosphate dehydrogenase (-7.5 and -7.5 kcal/mol). Chloroquine and hydroxychloroquine both had good affinity with angiotensin-converting enzyme 2, 3-chymotrypsin-like protease and transmembrane serine protease 2. However, hydroxychloroquine manifested better binding affinity with the three proteins comparing with that of chloroquine. Chloroquine and hydroxychloroquine could have potential to inhibit over-activated immunity and inflammation. The potential tissue-specific regulation of the two drugs against severe acute respiratory syndrome coronavirus 2 infection may related with the lung, liver, brain, placenta, kidney, blood, eye, etc. In conclusion, our data systematically demonstrated chloroquine and hydroxychloroquine may have potential regulatory effects on coronavirus disease 2019 disease network, which may affect multiple organs, protein targets and pathways. Routine measurements of the chloroquine and hydroxychloroquine blood concentrations and tailored therapy regimen may be essential. But, further rigorous and high quality randomized controlled clinical trials are warranted to validate the antiviral effects of chloroquine and hydroxychloroquine against severe acute respiratory syndrome coronavirus 2. Our proposed strategy could facilitate the drug repurposing efforts for coronavirus disease 2019 treatment.

2.
2nd International Conference on Artificial Intelligence and Computer Engineering, ICAICE 2021 ; : 216-220, 2021.
Article in English | Scopus | ID: covidwho-1948770

ABSTRACT

China is the world's largest pork production and consumption country, with the improvement of people's living standards and consumption upgrade, people's demand for fresh pork and other fresh products is stronger. With the outbreak of African Swine Fever and COVID-19 in China in the past two years, cold chain transportation of pork will replace live pigs as the main mode of pork supply chain. As one of the most important branches of machine learning, deep learning has developed rapidly in recent years and attracted extensive attention at home and abroad. In order to improve the real-time detection of pork freshness, this paper experimented with a variety of deep learning frameworks to achieve pork freshness classification. In this paper, pork freshness is divided into 5 levels according to TVB-N content, and the pictures taken are trained by different deep learning networks, including VGG, GoogLeNet and RestNet. After analyzing the training situation of each network, the advantages of different networks are absorbed and a new improved neural network is built to predict pork freshness. The final classification accuracy reached 97%, Indicating that this is a very efficient and accurate pork freshness classification method. © 2021 IEEE.

3.
Developments in Marketing Science: Proceedings of the Academy of Marketing Science ; : 269-281, 2022.
Article in English | Scopus | ID: covidwho-1930279

ABSTRACT

In 2020, online purchases have increasingly become a coping mechanism for those affected by the COVID-19 pandemic. This study explores the antecedents of impulsive behavior and investigates the kind of products that are bought in response to the pandemic. First, the study aims at understanding the role retail websites, as online marketing stimuli, play on impulsive buying. Likewise, the relationships that product involvement, perceived usefulness, perceived enjoyment, and hedonic values have on consumers’ impulsive behavior are investigated. Finally, the types of product bought are identified. An online survey was conducted using a convenience sample of college students. Overall, the study presents a nested model identifying the direct effect of hedonic values on the urge to purchase a product. Participants indicated personal care, followed by sports equipment, were significantly more likely to be purchased because of the pandemic than any category. Yet, those who believe they engaged in the online purchase because of the pandemic cues were more likely to purchase all kinds of product categories, including products for group and products for individual consumption. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

4.
Journal of Image and Graphics ; 27(6):1723-1742, 2022.
Article in Chinese | Scopus | ID: covidwho-1903894

ABSTRACT

Public security and social governance is essential to national development nowadays. It is challenged to prevent large-scale riots in communities and various city crimes for spatial and times caled social governance in corona virus disease 2019(Covid-19) like highly accurate human identity verification, highly efficient human behavior analysis and crowd flow track and trace. The core of the challenge is to use computer vision technologies to extract visual information in complex scenarios and to fully express, identify and understand the relationship between human behavior and scenes to improve the degree of social administration and governance. Complex scenarios oriented visual technologies recognition can improve the efficiency of social intelligence and accelerate the process of intelligent social governance. The main challenge of human recognition is composed of three aspects as mentioned below: 1) the diversity attack derived from mask occlusion attack, affecting the security of human identity recognition;2) the large span of time and space information has affected the accuracy of multiple ages oriented face recognition (especially tens of millions of scales retrieval);3) the complex and changeable scenarios are required for the high robustness of the system and adapt to diverse environments. Therefore, it is necessary to facilitate technologies of remote human identity verification related to the high degree of security, face recognition accuracy, human behavior analysis and scene semantic recognition. The motion analysis of individual behavior and group interaction trend are the key components of complex scenarios based human visual contexts. In detail, individual behavior analysis mainly includes video-based pedestrian re-recognition and video-based action recognition. The group interaction recognition is mainly based on video question-and-answer and dialogue. Video-based network can record the multi-source cameras derived individuals/groups image information. Multi-camera based human behavior research of group segmentation, group tracking, group behavior analysis and abnormal behavior detection. However, it is extremely complex that the individual behavior/group interaction is recorded by multiple cameras in real scenarios, and it is still a great challenge to improve the performance of multi-camera and multi-objective behavior recognition through integrated modeling of real scene structure, individual behavior and group interaction. The video-based network recognition of individual and group behavior mainly depends on visual information in related to scene, individual and group captured. Nonetheless, complex scenarios based individual behavior analysis and group interaction recognition require human knowledge and prior knowledge without visual information in common. Specifically, a crowd sourced data application has improved visual computing performance and visual question-and-answer and dialogue and visual language navigation. The inherited knowledge in crowd sourced data can develop a data-driven machine learning model for comprehensive knowledge and prior applications in individual behavior analysis and group interaction recognition, and establish a new method of data-driven and knowledge-guided visual computing. In addition, the facial expression behavior can be recognized as the human facial micro-motions like speech the voice of language. Speech emotion recognition can capture and understand human emotions and beneficial to support the learning mode of human-machine collaboration better. It is important for research to get deeper into the technology of human visual recognition. Current researches have been focused on human facial expression recognition, speech emotion recognition, expression synthesis, and speech emotion synthesis. We carried out about the contexts of complex scenarios based real-time human identification, individual behavior and group interaction understanding analysis, visual speech emotion recognition and synthesis, comprehensive utilization of knowledge and a priori mode of ma hine learning. The research and application scenarios for the visual ability is facilitated for complex scenarios. We summarize the current situations, and predict the frontier technologies and development trends. The human visual recognition technology will harness the visual ability to recognize relationship between humans, behavior and scenes. It is potential to improve the capability of standard data construction, model computing resources, and model robustness and interpretability further. © 2022, Editorial Office of Journal of Image and Graphics. All right reserved.

5.
Advances in Terahertz Biomedical Imaging and Spectroscopy 2022 ; 11975, 2022.
Article in English | Scopus | ID: covidwho-1891714

ABSTRACT

Currently, aerosol is considered as the major route for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. A safe sterilization method with an excellent penetration capability and ability to sterilize free spaces is urgently needed. Previously it has been experimentally demonstrated that microwave-based sterilization can effectively inactivate the H3N2 Influenza A virus through the structure-resonant energy transfer (SRET) effect with a radiation field intensity following the IEEE standard. In order to utilize the same mechanism to inactivate the SARS-CoV-2 virus, firstly, the structural resonant frequencies with electromagnetic (EM) waves have to be identified. In this paper we report our design and implementation of a spectrum measurement chip utilizing the coplanar waveguide with pre-printed mask. With the mask, the repeatability of the insertion loss measurement can be well-controlled. Our microwave absorption spectra results revealed that the coplanar-waveguide chip can identify the resonant microwave frequencies of difference viruses, including the SARS-CoV-2 viruses, highlighting the potential applications for not only the virus detection but also the safe and non-thermal sterilization of public spaces. During the presentation, we will also report the resonant EM wave frequencies of various corona viruses monitored by the aforementioned chip. Copyright © 2022 SPIE.

6.
IEEE Global Communications Conference (GLOBECOM) ; 2021.
Article in English | Web of Science | ID: covidwho-1853432

ABSTRACT

In this paper, we investigate the close contact detection for COVID-19 patients based on the heterogeneous mobile edge computing (MEC) framework. Collecting the spatial-temporal data of a large number of mobile users, the base stations equipped with MEC servers organize these data via the R-tree structure. The cloud center (CC) aggregates the spatial-temporal data from all MEC servers. Considering the mobility of users as well as various positions of MEC servers, the CC then partitions and assigns the close contact detection tasks to different servers for faster processing. Aiming to minimize the system latency, we propose a Deep Deterministic Policy Gradient-based task and resource allocation scheme, where the computing loads are balanced among different servers. Simulation results show that a minimum system latency is reached while maintaining the load balance among all servers. Up to 37% detection accuracy enhancement is achieved compared with an existing task allocation scheme without load balance.

7.
Environmental Chemistry ; 40(7):1945-1957, 2021.
Article in Chinese | Scopus | ID: covidwho-1847652

ABSTRACT

Since the outbreak of the new coronavirus pneumonia (COVID-19) in December 2019, it has caused millions of deaths in more than 200 countries all over the world, and the global economic development has been severely impacted. Concerning the new type of coronavirus (SARS-CoV-2) that caused the epidemic, scientific research has been actively carried out around the world as well as various prevention and control measures, which made important contribution to protect human health. However, as one of the countries that made outstanding achievements in the prevention and control of the epidemic, there were some regional epidemics of “object-to-human transmission” and then “human-to-human transmission ” occurred after June 2020, indicating the complexity of the spread of SARS-CoV-2. In addition, the development of COVID-19 in some contraries is going uncontrollable recently, and infection cases of the SARS-CoV-2 variant strain have appeared in many countries, which made the prevention and control of the epidemic more difficult. This article briefly reviewed the updated research works on SARS-CoV-2, including possible sources of virus and infection mechanisms, diagnosis and treatment approaches, transmission characteristics and environmental impact, etc. In particular, the environmental factors affecting the transmission of SARS-CoV-2 are summarized in order to enhance the understanding of environmental transmission of SARS-CoV-2. © 2021, Science Press. All rights reserved.

8.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(4): 474-478, 2022 Apr 06.
Article in Chinese | MEDLINE | ID: covidwho-1834947

ABSTRACT

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.


Subject(s)
COVID-19 , Contact Tracing , Cohort Studies , Humans , Incidence , Prospective Studies
9.
Embase; 2022.
Preprint in English | EMBASE | ID: ppcovidwho-334805

ABSTRACT

Omicron sub-lineage BA.2 has rapidly surged globally, accounting for over 60% of recent SARS-CoV-2 infections. Newly acquired RBD mutations and high transmission advantage over BA.1 urge the investigation of BA.2's immune evasion capability. Here, we show that BA.2 causes strong neutralization resistance, comparable to BA.1, in vaccinated individuals' plasma. However, BA.2 displays more severe antibody evasion in BA.1 convalescents, and most prominently, in vaccinated SARS convalescents' plasma, suggesting a substantial antigenicity difference between BA.2 and BA.1. To specify, we determined the escaping mutation profiles1,2 of 714 SARS-CoV-2 RBD neutralizing antibodies, including 241 broad sarbecovirus neutralizing antibodies isolated from SARS convalescents, and measured their neutralization efficacy against BA.1, BA.1.1, BA.2. Importantly, BA.2 specifically induces large-scale escape of BA.1/BA.1.1effective broad sarbecovirus neutralizing antibodies via novel mutations T376A, D405N, and R408S. These sites were highly conserved across sarbecoviruses, suggesting that Omicron BA.2 arose from immune pressure selection instead of zoonotic spillover. Moreover, BA.2 reduces the efficacy of S309 (Sotrovimab)3,4 and broad sarbecovirus neutralizing antibodies targeting the similar epitope region, including BD55-5840. Structural comparisons of BD55-5840 in complexes with BA.1 and BA.2 spike suggest that BA.2 could hinder antibody binding through S371F-induced N343-glycan displacement. Intriguingly, the absence of G446S mutation in BA.2 enabled a proportion of 440-449 linear epitope targeting antibodies to retain neutralizing efficacy, including COV2-2130 (Cilgavimab)5. Together, we showed that BA.2 exhibits distinct antigenicity compared to BA.1 and provided a comprehensive profile of SARS-CoV-2 antibody escaping mutations. Our study offers critical insights into the humoral immune evading mechanism of current and future variants.

10.
PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-333823

ABSTRACT

Antibodies that potently neutralize SARS-CoV-2 target mainly the receptor-binding domain or the N-terminal domain (NTD). Over a dozen potently neutralizing NTD-directed antibodies have been studied structurally, and all target a single antigenic supersite in NTD (site 1). Here we report the 3.7 A resolution cryo-EM structure of a potent NTD-directed neutralizing antibody 5-7, which recognizes a site distinct from other potently neutralizing antibodies, inserting a binding loop into an exposed hydrophobic pocket between the two sheets of the NTD beta-sandwich. Interestingly, this pocket has been previously identified as the binding site for hydrophobic molecules including heme metabolites, but we observe their presence to not substantially impede 5-7 recognition. Mirroring its distinctive binding, antibody 5-7 retains a distinctive neutralization potency with variants of concern (VOC). Overall, we reveal a hydrophobic pocket in NTD proposed for immune evasion can actually be used by the immune system for recognition. HIGHLIGHTS: Cryo-EM structure of neutralizing antibody 5-7 in complex with SARS CoV-2 spike5-7 recognizes NTD outside of the previously identified antigenic supersite5-7 binds to a site known to accommodate numerous hydrophobic ligandsStructural basis of 5-7 neutralization tolerance to some variants of concern.

11.
PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-333657

ABSTRACT

Understanding protective mechanisms of antibody recognition can inform vaccine and therapeutic strategies against SARS-CoV-2. We discovered a new antibody, 910-30, that targets the SARS-CoV-2 ACE2 receptor binding site as a member of a public antibody response encoded by IGHV3-53/IGHV3-66 genes. We performed sequence and structural analyses to explore how antibody features correlate with SARS-CoV-2 neutralization. Cryo-EM structures of 910-30 bound to the SARS-CoV-2 spike trimer revealed its binding interactions and ability to disassemble spike. Despite heavy chain sequence similarity, biophysical analyses of IGHV3-53/3-66 antibodies highlighted the importance of native heavy:light pairings for ACE2 binding competition and for SARS-CoV-2 neutralization. We defined paired heavy:light sequence signatures and determined antibody precursor prevalence to be ~1 in 44,000 human B cells, consistent with public antibody identification in several convalescent COVID-19 patients. These data reveal key structural and functional neutralization features in the IGHV3-53/3-66 public antibody class to accelerate antibody-based medical interventions against SARS-CoV-2. HIGHLIGHTS: A molecular study of IGHV3-53/3-66 public antibody responses reveals critical heavy and light chain features for potent neutralizationCryo-EM analyses detail the structure of a novel public antibody class member, antibody 910-30, in complex with SARS-CoV-2 spike trimerCryo-EM data reveal that 910-30 can both bind assembled trimer and can disassemble the SARS-CoV-2 spikeSequence-structure-function signatures defined for IGHV3-53/3-66 class antibodies including both heavy and light chainsIGHV3-53/3-66 class precursors have a prevalence of 1:44,000 B cells in healthy human antibody repertoires.

12.
PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-333560

ABSTRACT

Coagulopathy is associated with both inflammation and infection, including infection with the novel SARS-CoV-2 (COVID-19). Endothelial cells (ECs) fine tune hemostasis via cAMP-mediated secretion of von Willebrand factor (vWF), which promote the process of clot formation. The e xchange p rotein directly a ctivated by c AMP (EPAC) is a ubiquitously expressed intracellular cAMP receptor that plays a key role in stabilizing ECs and suppressing inflammation. To assess whether EPAC could regulate vWF release during inflammation, we utilized our EPAC1 -null mouse model and revealed an increased secretion of vWF in endotoxemic mice in the absence of the EPAC1 gene. Pharmacological inhibition of EPAC1 in vitro mimicked the EPAC1 -/- phenotype. EPAC1 regulated TNFalpha-triggered vWF secretion from human umbilical vein endothelial cells (HUVECs) in a phosphoinositide 3-kinases (PI3K)/endothelial nitric oxide synthase (eNOS)-dependent manner. Furthermore, EPAC1 activation reduced inflammation-triggered vWF release, both in vivo and in vitro . Our data delineate a novel regulatory role of EPAC1 in vWF secretion and shed light on potential development of new strategies to controlling thrombosis during inflammation. KEY POINT: PI3K/eNOS pathway-mediated, inflammation-triggered vWF secretion is the target of the pharmacological manipulation of the cAMP-EPAC system.

13.
IEEE Access ; 2022.
Article in English | Scopus | ID: covidwho-1788615

ABSTRACT

The COVID-19 pandemic has made the scientific community devise means to implement “contact tracing" mechanisms to mitigate the spread of the infection. The crucial idea is to scan and record close contacts between users using mobile device, in order to notify persons when their close contact(s) is diagnosed positive. First, the ability granted to service providers of the contact tracing systems to access user data violates user privacy, and attackers can fabricate identities and contact records in their devices, which harms the integrity of the system. Moreover, current contact tracing systems’false-positive rate is too high to be practical as they do not filter scan results outside the range of infections, since the range of transmission for droplets is far less than the scanning range for Bluetooth Low Energy used by these systems. Furthermore, current systems neglect airborne transmission, a far cry from a tool against viruses suspended in the air. In this paper, we propose a cryptographic framework for contact tracing and provide a construction based on public key rerandomizable BLS signature, being capable of providing users of contact tracing with comprehensive privacy protection. Besides, we also implement a commitment scheme to prevent fabrication of identities and contact records. To prove the concept of our framework and to solve other problems mentioned above, we proposed a new contact tracing system, using environmental factors (temperature, humidity and airflow) to filter out results outside estimated effective transmission distance, and also take airborne transmission into consideration. Finally, we evaluate the performance of our design by implementing our algorithm on mobile devices with satisfactory results. Author

14.
2021 IEEE Global Communications Conference, GLOBECOM 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1784483

ABSTRACT

In this paper, we investigate the close contact detection for COVID-19 patients based on the heterogeneous mobile edge computing (MEC) framework. Collecting the spatial-temporal data of a large number of mobile users, the base stations equipped with MEC servers organize these data via the R-tree structure. The cloud center (CC) aggregates the spatial-temporal data from all MEC servers. Considering the mobility of users as well as various positions of MEC servers, the CC then partitions and assigns the close contact detection tasks to different servers for faster processing. Aiming to minimize the system latency, we propose a Deep Deterministic Policy Gradient-based task and resource allocation scheme, where the computing loads are balanced among different servers. Simulation results show that a minimum system latency is reached while maintaining the load balance among all servers. Up to 37% detection accuracy enhancement is achieved compared with an existing task allocation scheme without load balance. © 2021 IEEE.

15.
Journal of Clinical Oncology ; 40(6 SUPPL), 2022.
Article in English | EMBASE | ID: covidwho-1779695

ABSTRACT

Background: There is a need for a low toxicity option for men with prostate cancer with biochemical recurrence (BCR) following primary curative therapy. Cannabinoids (CBD) have antitumor activity in preclinical studies, but products may vary in activity without clear standardization. As epidiolex is a standardized FDA approved oral CBD solution for treatment of certain types of seizures, we studied epidiolex in patients with BCR of prostate cancer to determine safety and dosing of this therapy to support future studies. Methods: We present an open-label, single center, phase I dose escalation study followed by a dose expansion. Patients with BCR prostate cancer after primary definitive local therapy (prostatectomy +/- salvage radiotherapy or primary definitive radiotherapy) were eligible. Majority of our patients' prostate-specific antigen (PSA) doubling time was ≤ 12 months. All patients were screened for urine tetrahydrocannabinol (THC) prior to enrollment. With use of a Bayesian optimal interval design, patients received escalating doses of epidiolex starting at 600mg daily and up to 800mg daily. All patients were treated for 90 days followed by a 10 day taper. The Primary endpoints were safety and tolerability. Patients were monitored for both acute (30 days) and chronic (90 days) treatment-related toxicities. Secondary endpoints included change in PSA levels and testosterone levels from baseline throughout the treatment period. Results: A total of 21 patients were enrolled but four withdrew from the study (one patient was hospitalized with COVID-19 and three patients requested to stop due to grade 2 adverse events (AEs). There were seven patients included in the dose escalation phase. Four patients received 600mg daily;two of the four in this phase did not finish the first 30 days (one with COVID-19 and one withdrew). The other three patients received 800 mg daily. No dose-limiting toxicities were observed at any dose level so an additional 14 patients were enrolled at the 800mg dose. Treatment-related chronic AEs occurring in >10% of patients were grade 1 or 2 diarrhea (47.6%), grade 1 or 2 nausea (23.8%) and grade 1 or 2 fatigue (19%). The mean PSA at baseline was 2.9 ng/ml. One patient developed oligo-metastasis disease, two patients progressed after the study period, and one patient died from a non-treatment or disease-related cause. Conclusions: Epidiolex at a dose of 800mg daily appears to be safe and tolerable in patients with BCR of prostate cancer, supporting a safe dose for future studies to determine if there is clinical activity to delay development of hormone refractory metastatic disease.

16.
10th International Conference of Educational Innovation through Technology, EITT 2021 ; : 63-68, 2021.
Article in English | Scopus | ID: covidwho-1769573

ABSTRACT

To examine the online teaching attitudes of university teachers and the influencing factors during the Covid-19 pandemic, this study conducted a large-scale survey (N=1090) on university teachers in 16 provinces in China. A series of Kruskal-Wallis nonparametric tests were performed to determine the impact of teacher demographic characteristics on their online teaching attitudes. The results revealed that most teachers had positive opinions of online instruction with several perceived benefits, but also recognized the challenges and disadvantages to teach online. The differences in age, educational background, professional titles and prior online teaching experience significantly affected teachers' attitudes towards online teaching. The study concluded with several implication for preparing university teachers for online instruction in the post-pandemic world. © 2021 IEEE.

17.
Open Public Health Journal ; 14:592-599, 2021.
Article in English | Scopus | ID: covidwho-1745216

ABSTRACT

Aims: The study examines the factors related to the appraisal and adherence of the individual and public health preventive measures. Background: The effectiveness of the measures battling the pandemic was largely determined by the voluntary compliance of the public. Objectives: This study aimed to identify psychological perception factors related to the appraisal of individual measures and endorsement of public health measures during the early stage of the COVID-19 pandemic among Chinese living in Canada. Methods: A convenience sample of 656 participants completed an online survey. Nonparametric Kruskal Wallis tests were used to compare COVID perception variables (e.g., perceived susceptibility, fear, perceived severity, and information confusion) among different sociodemographic subgroups. Bootstrapped regression models were used to assess the association of these variables with outcome measures. Results: Compared to their counterpart groups, lower perceived susceptibility was reported by adults 65 years and older (p = .002) or retired (p = .015);greater fear was reported by females (p = .044), those with lower education (p = .001), and Mainland Chinese (p = .033);greater perceived severity was reported by individuals with lower education and smaller household size (ps = .003). Perceived susceptibility was inversely associated with individual measure appraisal (p = .032). Perceived severity was positively associated with individual measure appraisal (p = .005) and public measure endorsement (p < .001). Conclusion: Individual behaviour measure appraisal was predicted by lower perceived susceptibility and higher perceived severity, whereas public health measure endorsement was related to higher perceived severity. These results inform the public and the policymakers about the critical factors that affect the preventive measure appraisal and endorsement. © 2021 Na et al.

18.
BMC Geriatr ; 22(1): 184, 2022 03 05.
Article in English | MEDLINE | ID: covidwho-1724418

ABSTRACT

BACKGROUND: Age and comorbidities increase COVID-19 related in-hospital mortality risk, but the extent by which comorbidities mediate the impact of age remains unknown. METHODS: In this multicenter retrospective cohort study with data from 45 Dutch hospitals, 4806 proven COVID-19 patients hospitalized in Dutch hospitals (between February and July 2020) from the CAPACITY-COVID registry were included (age 69[58-77]years, 64% men). The primary outcome was defined as a combination of in-hospital mortality or discharge with palliative care. Logistic regression analysis was performed to analyze the associations between sex, age, and comorbidities with the primary outcome. The effect of comorbidities on the relation of age with the primary outcome was evaluated using mediation analysis. RESULTS: In-hospital COVID-19 related mortality occurred in 1108 (23%) patients, 836 (76%) were aged ≥70 years (70+). Both age 70+ and female sex were univariably associated with outcome (odds ratio [OR]4.68, 95%confidence interval [4.02-5.45], OR0.68[0.59-0.79], respectively;both p<  0.001). All comorbidities were univariably associated with outcome (p<0.001), and all but dyslipidemia remained significant after adjustment for age70+ and sex. The impact of comorbidities was attenuated after age-spline adjustment, only leaving female sex, diabetes mellitus (DM), chronic kidney disease (CKD), and chronic pulmonary obstructive disease (COPD) significantly associated (female OR0.65[0.55-0.75], DM OR1.47[1.26-1.72], CKD OR1.61[1.32-1.97], COPD OR1.30[1.07-1.59]). Pre-existing comorbidities in older patients negligibly (<6% in all comorbidities) mediated the association between higher age and outcome. CONCLUSIONS: Age is the main determinant of COVID-19 related in-hospital mortality, with negligible mediation effect of pre-existing comorbidities. TRIAL REGISTRATION: CAPACITY-COVID ( NCT04325412 ).


Subject(s)
COVID-19 , Aged , Comorbidity , Female , Hospital Mortality , Hospitalization , Humans , Male , Retrospective Studies , Risk Factors , SARS-CoV-2
19.
2021 IEEE Biomedical Circuits and Systems Conference, BioCAS 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1706669

ABSTRACT

Photoplethysmography (PPG) sensing is a popular optical method used to determine blood oxygen saturation and heart rate based on light reflected from a patient's skin. Both health metrics are useful in detecting COVID-19 in asymptomatic patients but remain impacted by physiological differences in individuals. In the context of wearable self-powered devices, PPG sensing is relatively high-power compared to available on-body energy. This paper presents a PPG sensing model, with a transimpedance amplifier (TIA) to demonstrate power, signaling, and design tradeoffs, and a photodiode model that includes the impact of a patient's skin phototype on reflected light and PPG sensing accuracy. It also presents preliminary measured results from on-body testing with existing hardware to verify the power and ability to extract a PPG signal at those power levels. This model demonstrates the need to first identify the minimum allowable photodiode current that can produce accurate results for each skin phototype and then determine user-specific circuit knobs to achieve personalized PPG sensing with optimized power consumption. © 2021 IEEE.

20.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-326985

ABSTRACT

The massive and rapid transmission of SARS-CoV-2 has led to the emergence of several viral variants of concern (VOCs), with the most recent one, B.1.1.529 (Omicron), which accumulated a large number of spike mutations, raising the specter that this newly identified variant may escape from the currently available vaccines and therapeutic antibodies. Using VSV-based pseudovirus, we found that Omicron variant is markedly resistant to neutralization of sera form convalescents or individuals vaccinated by two doses of inactivated whole-virion vaccines (BBIBP-CorV). However, a homologous inactivated vaccine booster or a heterologous booster with protein subunit vaccine (ZF2001) significantly increased neutralization titers to both WT and Omicron variant. Moreover, at day 14 post the third dose, neutralizing antibody titer reduction for Omicron was less than that for convalescents or individuals who had only two doses of the vaccine, indicating that a homologous or heterologous booster can reduce the Omicron escape from neutralizing. In addition, we tested a panel of 17 SARS-CoV-2 monoclonal antibodies (mAbs). Omicron resists 7 of 8 authorized/approved mAbs, as well as most of the other mAbs targeting distinct epitopes on RBD and NTD. Taken together, our results suggest the urgency to push forward the booster vaccination to combat the emerging SARS-CoV-2 variants.

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