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Based on signal amplification strategy of dendritic mesoporous silica nanospheres loaded with CdSe/ZnS quantum dots (DMSN@QDs), an ultrasensitive electrochemiluminescence (ECL) immunosensor with magnetic separation was constructed for the detection of SARS-CoV-2 nucleocapsid protein (NP). DMSN, a mesoporous material with abundant radial pores, large specific surface area and high porosity, can increase the loading capacity of QDs and hinder their aggregation as the nanocarrier. DMSN@QDs with good ECL efficiency were used as signal labels to construct a sandwich immunosensor. The designed ECL immunosensor displayed a good linear relationship for NP concentrations ranging from 0.005 ng mL(-1) to 50 ng mL(-1), with a limit of detection of 3.33 pg mL(-1). The ECL immunosensor was successfully applied to detect NP in human serum samples with satisfactory recovery. This strategy provided a new method for detecting NP and expanded the application field of DMSN.
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The removal and defense mechanisms of the respiratory system of patients with pneumoconiosis are impaired. Once patients with pneumoconiosis and other underlying lung diseases are infected with novel coronavirus, they are likely to progress to severe cases with COVID-19, a tough condition with a high mortality and poor prognosis. Herein we presented a case of pneumoconiosis and tuberculosis complicated with severe COVID-19. Active administration of anti-viral, anti-infection, phlegm-removing, anti-asthmatic, and high-flow oxygen therapies did not alleviate the patient's acute respiratory distress syndrome symptoms. Then tracheal intubation, ventilator assisted breathing, and lung protective ventilation were given but did not effectively treat the patient's respiratory failure. Finally, the patient died clinically despite use of extracorporeal membrane oxygenation (ECMO).Copyright © 2021, Shanghai Municipal Center for Disease Control and Prevention. All rights reserved.
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In 2021, the contradiction between natural gas supply and demand in various regions around the world was prominent caused by multiple factors, such as the reduced global COVID-19, slowly recovered world economy, resumed growth of energy consumption, intertwined geopolitical and financial risks, significantly risen and violently fluctuated energy prices. The global natural gas development trend is predicted by analyzing the development direction of the petroleum industry, natural gas supply and demand base level, trend of trade volume, and natural gas reserves distribution and output change. The results show that natural gas reserves are abundant in the world, and the investment in natural gas exploration and development has rebounded driven by the demand growth and price rise;The proportion of natural gas in the world energy consumption structure is increasing, which plays an important role in promoting the global energy transition;The global natural gas supply and demand shows a pattern of "tight balance”, in which the Asia Pacific is the major importer of natural gas, and it is expected that natural gas will surpass oil to grow to be the world's largest energy. In the future, it is suggested that China should actively adjust its energy strategy, enhance its linkage with international energy market, improve the energy prices monitoring and judgement mechanism, timely adjust its foreign strategic cooperation in energy business, increase domestic investment in natural gas exploration and development, enhance multilateral international energy cooperation, and stick to the bottom line of energy security, accelerate the construction of natural gas operation system integrating "reserve increase, supply security and price stabilization”, and improve the ability to respond to crises, so as to better cope with the challenges posed by global energy development and natural gas market fluctuations. Copyright © 2022, Petroleum Industry Press, PetroChina. All rights reserved.
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It is necessary to ensure the quality of students' courses, especially practical courses, which is an important part of higher education, and plays a positive role in promoting and popularizing the improvement of innovation and entrepreneurship in the face of the non suspension of classes and schools under the COVID-19. This paper explores the mode of online and offline combined with ideological and political education mixed teaching reform in the course, in order to explore the educational functions and ideological and political elements of the course from the practical contents and objectives from the practical course of artificial intelligence foundation, explore the implementation methods and teaching concepts of ideological and political education in the course, so that students can better master and understand knowledge comprehensively, improve the results of students' ideological and moral education, and explore the reform mode which satisfy the requirements of talent training. © 2022 IEEE.
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Background: Over 214 million students globally have been affected by school closures during the COVID-19 pandemic. To address knowledge gaps on transmission of SARS-CoV-2 delta (B.1.617.2) and omicron (B.1.1.529) variants in educational settings we examined virus transmission in schools and early childhood education and care settings (ECECs) in New South Wales (NSW), Australia in relation to mitigation measures, including COVID-19 vaccination. Methods: Secondary transmission from children and adults with laboratory-confirmed SARS-CoV-2 infection who attended a school (n = 3170) or ECECs (n = 5800) while infectious was investigated over two periods: 1) June 16 to September 18, 2021 (delta outbreak), and; 2) October 18 to December 18, 2021 (delta and omicron; schools only). Close contacts of cases underwent 14 days quarantine and SARS-CoV-2 nucleic acid testing. Secondary attack rates (SARs) were calculated and compared with state-wide notification data, school attendance, and vaccination status. Findings: 1187 schools and 300 ECECs had students (n = 1349) or staff (n = 440) attend while infectious. Of 24,277 contacts investigated, most (91.8%; 22,297/24,277) were tested and 912 secondary cases identified. The secondary attack rate (SAR) was 5.9% in 139 ECECs and 3.5% in 312 schools. The risk of becoming a secondary case was higher in unvaccinated school staff (OR 4.7; 95% CI: 1.7-13.3), particularly ECEC staff (OR 9.0; 95% CI: 3.6-22.7) and unvaccinated school students than in vaccinated school staff. SARs were similar for delta (4.9%) and omicron BA.1 (4.1%) in the unvaccinated and higher compared with vaccinated contacts (0.9% and 3.4%, respectively). Increasing school attendance rates raised case incursions and secondary case numbers, but not community-wide infection rates. Interpretation: Vaccination reduced SARS-CoV-2 transmission rates in schools, although less so for omicron than delta variants. Despite higher community-based transmission rates, in-school transmission remained low and stable with high attendance, suggesting that community restrictions, rather than school closures, best mitigated COVID-19 impacts. Funding: NSW Government Department of Health.
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Inexpensive iron-based catalysts are the most promising catalysts for microwave pyrolysis of waste plastics, especially a large number of disposable medical masks (DMMs) with biological hazards produced by spread of COVID-19. However, most synthesized iron-based catalysts have very low microwave heating efficiency due to the enrichment state of iron. Here, we prepared FeAlOx catalysts using the microwave heating method and found that the microwave heating efficiency of amorphous iron and hematite is very low, indeed, these materials can hardly initiate pyrolysis at room temperature, which limits the application of iron-based catalysts in microwave pyrolysis. By contrast, a mixture of DMMs and low-valent iron oxides produced by hydrogen reduction at 500 °C can be heated by microwaves to temperatures above 900 °C under the same conditions. When the hydrogen reduction temperature was incerased to 800 °C, the content of metallic iron in the catalyst gradually increased from 0.34 to 21.43%, which enhanced the microwave response ability of the catalyst, and decreased the gas content in the pyrolysis product from 78.91 to 70.93 wt%;corresponding hydrogen yield also decreased from 29.03 to 25.02 mmolH2·g-1DMMs. Moreover, the morphology of the deposited solid carbon gradually changed from multi-walled CNTs to bamboo-like CNTs. This study clarifies the pyrolysis mechanism of microwave-assisted iron catalysts and lays a theoretical foundation for their application in microwave pyrolysis. © 2022 Elsevier Ltd
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Background. SARS-CoV-2 E gene PCRs have been widely used as the first-line assay with a higher sensitivity than those targeting N or RdRp gene. Given the currently available primers and probes were designed at the onset of the pandemic, it is unknown whether the SARS-CoV-2 VOCs have accumulated significant mutations that may affect E gene PCRs. In this study we aim to perform a comprehensive genetic analysis of SARS-CoV-2 E gene sequences to evaluate the impact of the emerging VOCs on E gene PCR performance. Methods. 600 whole-genome sequences of 7 species of human coronaviruses (HCoVs) were retrieved from GenBank and GISAID, including Sarbecoviruses (SARS-CoV-2 variants B1.1.7, B1.351, P.1, B.1.617.2 and B.1.1.529, and SARS-CoV), Embecovirus (OC43, HKU1), Merbecovirus (MERS) and Alphacoronaviruses (229E, NL63). The E gene sequences were retrieved from fulllength genomes of corresponding viruses and aligned by ClustalW multiple alignment. Phylogenetic, conservation and mutation analyses analysis of the enrolled sequences was performed. Results. E gene-based phylogenetic analysis yielded HCoVs typing results consistent with whole genome typing, suggesting E gene is a reliable locus for phylogenetic analysis and typing of HCoVs. Four pan-Sarbecovirus conserved E gene regions were identified with 100% conserved nucleotide similarity among SARS-CoV-2 and its VOCs, as well as SARS-CoV. These regions have appropriate G/C content which may be suitable for primer/probe design for E gene-based pan-Sarbecovirus screening assay. No significant E mutations were found in 137 retrieved SARS-CoV-2 and its VOCs. Interestingly, two novel variations, C26299U and T26354A, were identified in two of our SARS-CoV-2 strains. The latter variation occurred at the 3' end of the target region of the widely used Charite/Berlin (WHO) probe. This variant may lead to a potential failure of the first-line E gene PCR. Conclusion. Our data shed light on the genetic diversity and conservation of E gene of SARS-CoV-2 and may be beneficial for future primer/probe design for novel first-line assay or SARS-CoV-2-specific E gene PCR. SARS-CoV-2 VOCs have not accumulated significant mutations in E gene so far. The impact of novel E gene variations C26299U and T26354A on molecular diagnostic testing warrants further investigation.
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Microbial contamination and infection are global issues in the food and environmental fields that seriously threaten human health. Bacteria and fungi can easily cause food spoilage, resulting in diarrhea and vomiting;viruses can infect humans through different transmission routes, causing severe or even fatal harm. Hence, rapid analysis and identification of pathogenic microorganisms and simultaneous detection of multiple types of microbes have become hot research topics in biochemical analysis and molecular diagnosis. The lateral flow assay (LFA) is a simple, rapid, economical, and efficient detection technology with high sensitivity, simple operation, and environmental friendliness. It can provide instant test results under non-laboratory circumstances, hence becoming an ideal choice for point-of-care testing, which has been applied to rapidly detect various targets. The current conventional principle of the LFA is still based on the specific recognition of the antigen by the antibody. However, as a commonly used target recognition molecule in conventional biochemical and medical detection, the application of antibodies also has certain limitations for rapid and accurate identification of certain targets due to strict control of the production and purification process, as well as susceptibility to the interference of the operating environment, pH, temperature, and other conditions, such as long production cycle, high cost, poor stability, and cross-reactivity. Aptamers are a class of single-stranded DNA (ssDNA) or RNA obtained through the systematic evolution of ligands by exponential enrichment (SELEX), which can usually form a stable secondary structure. Aptamers can be folded into a three-dimensional structure through conformational change and interact with the target through conformation complementarity, π-π stacking between aromatic rings, base stacking, electrostatic interaction, and hydrogen bonding. So far, nearly 300 kinds of aptamers have been discovered. As alternatives, aptamers are easy and facile to modify and label with high sensitivity and specificity. Accordingly, the innovative rapid detection technique can be developed by combining the LFA with an aptamer. This aptamer-based LFA technology can be widely used in qualitative, semi-quantitative, and quantitative detection in food safety, environment, clinical, and other fields. Nowadays, most microbe detection methods are constructed based on this approach. The common strategies of aptamer-based LFAs include the sandwich method, competitive method, and adsorption–desorption method. Diverse ingenious materials such as gold nanoparticles and quantum dots have also been proposed for signal read-out. Different signal capture models, such as colorimetric and fluorescence methods, have been applied for sensitive and accurate detection of a single or multiple target microbe. Furthermore, in view of the unique properties of nucleic acid aptamers, several signal amplification methods can be further involved in the LFA to enhance the sensitivity for target detection. This review introduces the use of aptamers with different structural patterns and labeling types in recent years, as well as a variety of methods to detect microbes, especially for the rapid detection of pathogenic bacteria. Based on the excellent characteristics, the aptamer-based LFA presents more flexibility and selectivity for microbe detection with good applicability, specificity, and sensitivity and can better achieve low-cost, rapid detection. This study is expected to provide a reference for developing nucleic acid aptamer-based LFA technologies, especially for efficient and accurate diagnosis of corona virus disease 2019 (COVID-19), exploiting the novel application scope of LFA technology. © 2022 Chinese Academy of Sciences. All rights reserved.
ABSTRACT
This paper proposes an energy-efficient intelligent pulmonary auscultation system for post COVID-19 era wearable monitoring. This system consists of a tightly coupled two-stage hybrid neural network (TC-TSHNN) model and a corresponding multi-task training paradigm to improve prediction accuracy and generalization ability based on the fact that the number of COVID-19 patients is far less than that of normal people. At the first stage, two-category coarse classification is performed to identify normal and abnormal lung sounds. If the lung sound is abnormal, the second stage would be triggered to perform a four-category fine-grained classification. Besides, discrete wavelet transform is utilized for feature extraction, denoising and data reduction. In addition, advanced lightweight convolutional neural networks are used to reduce the model's computation and improve the model's performance. The hybrid network model can achieve 92% computation reduction and energy saving compared with a direct four-category classification when the input lung sound is normal, which is the majority of cases. Experiment results with inter-patient classification on the COVID-19 lung sound dataset from Tongji Hospital in Wuhan City and the ICBHI'17 dataset show that the proposed TC-TSHNN model can significantly reduce power consumption while maintaining competitive performance against the state-of-the-art work. © 2022 IEEE.
ABSTRACT
Inexpensive iron-based catalysts are the most promising catalysts for microwave pyrolysis of waste plastics, especially a large number of disposable medical masks (DMMs) with biological hazards produced by spread of COVID-19. However, most synthesized iron-based catalysts have very low microwave heating efficiency due to the enrichment state of iron. Here, we prepared FeAlOx catalysts using the microwave heating method and found that the microwave heating efficiency of amorphous iron and hematite is very low, indeed, these materials can hardly initiate pyrolysis at room temperature, which limits the application of iron-based catalysts in microwave pyrolysis. By contrast, a mixture of DMMs and low-valent iron oxides produced by hydrogen reduction at 500 degreeC can be heated by microwaves to temperatures above 900 degreeC under the same conditions. When the hydrogen reduction temperature was incerased to 800 degreeC, the content of metallic iron in the catalyst gradually increased from 0.34 to 21.43%, which enhanced the microwave response ability of the catalyst, and decreased the gas content in the pyrolysis product from 78.91 to 70.93 wt%;corresponding hydrogen yield also decreased from 29.03 to 25.02 mmolH2.g-1DMMs. Moreover, the morphology of the deposited solid carbon gradually changed from multi-walled CNTs to bamboo-like CNTs. This study clarifies the pyrolysis mechanism of microwave-assisted iron catalysts and lays a theoretical foundation for their application in microwave pyrolysis.
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The 13th Five-Year National Key Research and Development Program has established a key project of "Prevention and Control of Major Animal Diseases, Efficient and Safe Husbandry Technology Research and Development" (Animal Project), which supported scientific and technological innovation research in the field of animal epidemic prevention and control, efficient and safe breeding and breeding environment treatment. This project carried out the design of "whole chain design and integrated implementation" according to basic research, key technology research and development and integrated demonstration to solve the important basic theory and technical bottleneck of animal breeding in China. Based on the method of bibliometric, a statistical analysis was conducted of the papers supported mainly by the project to master the research progress and hot spots of the special project in basic research and frontier theory. Moreover, the future key research direction and development trend in the field of animal husbandry and veterinary medicine was discussed in combination with the layout of animal husbandry and veterinary related projects in the 14th Five-Year Plan. The results showed that this special funded papers had achieved breakthrough research in the basic research fields of major animal diseases and zoonotic diseases such as the COVID-19, Zika virus and African Swine Fever Achievements: Agriculture-related universities and scientific research institutes cooperate closely and have made great contributions;International cooperation is not only with the United States and other developed countries, but also closely cooperated with developing countries such as Pakistan and Egypt related to the "Belt and Road" initiative. The probability of publishing high-quality papers which cooperated with scientific research teams in developed countries has increased significantly;Research hotspots mainly focus on epidemiology, pathogen replication and evolution, drug resistance, pathogen and host interaction and network regulation, immune and pathogenic mechanisms, cross-species transmission, etc. The livestock and poultry special project focuses on the research direction of the prevention and control of major livestock and poultry diseases and efficient and safe breeding, and has made important research progress in major basic theories, supporting the research and application demonstration of key core technologies. The 14th Five-Year National Key Research and Development Program will make a comprehensive layout in the field of animal seed industry innovation, prevention and control of animal diseases, purification and eradication, nutrition regulation and efficient breeding, waste resource utilization and green breeding, breeding equipment and intelligent breeding. Copyright © 2022 Editorial Board, Institute of Animal Science of the Chinese Academy of Agricultural Sciences.
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In the current hotel sales trend due to COVID-19 pandemic, few empirical studies have discussed hotel appraisal determinants and prioritization in terms of operational efficiency. This paper presents an innovative approach for appraisal practice efficiency based on hotel appraisal approach and the multiple criteria decision making (MCDM). The DANP-mV model is used to identify the determinants related to actual hotel appraisal practices, including the techniques of the decision-making trial and evaluation laboratory (DEMATEL), DEMATEL-based ANP (DANP), and modified VIKOR. The result of influential network relationship map (INRM) and the gaps of determinants to the aspiration level may contribute to improving hotel appraisal efficacy. In practice, the “discounted cash flow” becomes the most influential determinant (di-mension) and the “market survey” is the most manageable one. More findings together with an action plan are presented and useful in the real world. Therefore, this innovative approach could help hotel appraisers and related parties, such as hospitality managers, investors, lenders, and decision makers, better manage the evaluation determinants of hotel appraisal efficacy. © 2022 The Author(s).
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Atypical disease presentations are common in older adults with COVID-19. The objective of this study was to determine the prevalence of atypical and typical symptoms in older adults with COVID-19 through progressive pandemic waves and the association of these symptoms with in -hospital mortality. This retrospective cohort study included consecutive adults aged over 65 years with confirmed COVID-19 infection who were admitted to seven hospitals in Toronto, Canada, from 1 March 2020 to 30 June 2021. The median age for the 1786 patients was 78.0 years and 847 (47.5%) were female. Atypical symptoms (as defined by geriatric syndromes) occurred in 1187 patients (66.5%), but rarely occurred in the absence of other symptoms (n = 106;6.2%). The most common atypical symptoms were anorexia (n = 598;33.5%), weakness (n = 519;2 3.9%), and delirium (n = 449;25.1%). Dyspnea (adjusted odds ratio [aOR] 2.05;95% confidence interval [CI] 1.62-2.62), tachycardia (aOR 1.87;95% CI 1.14-3.04), and delirium (aOR 1.52;95% CI 1.18-1.96) were inde-pendently associated with in-hospital mortality. In a cohort of older adults hospitalized with COVID-19 infection, atypical presentations frequently overlapped with typical symptoms. Further research should be directed at understanding the cause and clinical significance of atypical presenta-tions in older adults.
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With the winter season approaching and recommencement of international travel in 2022, influenza and COVID-19 vaccination will be crucial for protecting individuals from infection and reducing healthcare burden. Current Australian guidelines recommend influenza and COVID-19 vaccines can be coadministered, highlighting an important opportunity for disease prevention by GPs.
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The spread of fake news on online media is very dangerous and can lead to casualties, effects on psychology, character assassination, elections for political parties, and state chaos. Fake news that concerning Covid-19 massively spread during the pandemic. Detecting misinformation on the Internet is an essential and challenging task since humans face difficulty detecting fake news. We applied BERT and GPT2 as pre-trained using the BiGRU-Att-CapsuleNet model and BiGRU-CRF features augmentation to solve Fake News detection in Constraint @ AAAI2021-COVID19 Fake News Detection in English Dataset. This research proved that our hybrid model with augmentation got better accuracy compared to our baseline model. It also showed that BERT gave a better result than GPT2 in all models;the highest accuracy we achieved for BERT is 0.9196, and GPT2 is 0.8986. © 2022, ComSIS Consortium. All rights reserved.
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Both 5G Internet and COVID-19 pandemic have increasingly prompted thousands of companies and organizations to shift from a centralized office model to a distributed home model, which poses a new requirement: how to securely and rapidly share private data for coworkers on Internet. The covert communication systems are widely used to deliver private information because of the possibility of extending the system to Internet-scale size. However, most existing systems are inadequate to solve the requirement, since either the servers in centralized systems face the risk of being monitored and infiltrated, or the multi-hop routing schemes in decentralized systems lead to diverse attacks and high delivery latency. To this end, we proposed a scalable covert communication service for coworkers, called SC2. For security and hiddenness, we adopt the content slicing and multichannel routing to prevent adversary from monitoring and analyzing data. For scalability, we design a two-hop logic overlay to support low latency routing, and an adaptive channel selction technique to exploit the available bandwidth of the system. To evaluate the performance of SC2, we deploy the system in various IoT clouds and storage clouds. The experimental results demonstrate that SC2 is able to transmit both short messages and bulk content. Under various parameter settings, the delivery latency of SC2 linearly decreases with the number of channels, and SC2 takes full advantage of the available bandwidth with the growing number of users. © 2022 IEEE.
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Background: Teledermatology is an effective healthcare delivery model that has seen tremendous expansion over the last decade, which has been particularly pronounced during the Coronavirus Disease 2019 (COVID-19) pandemic. Objective: To better understand teledermatology utilization and patient demographic trends throughout the COVID-19 pandemic. Methods: National-level data were curated for all practices enrolled in the American Academy of Dermatology’s DataDerm registry from April 1, 2020, through June 30, 2021. Encounter utilization rates were collected for visit type (i.e., teledermatology versus in-person), sex, race, age, insurance provider, and location. Results: Data from up to 13,964,816 encounters across the United States were analyzed. Sex, race, age, insurance provider, and location were each found to have a significant association with telemedicine utilization (adjusted p<0.001). The proportion of women who utilized services via teledermatology (n=65,023, 66.0%) was greater than those who utilized in-person services (n=2,940,122, 58.3%). Non-white patients made up a higher percentage of teledermatology utilizers (n=8,920, 14.3%) when compared to in-person utilizers (n=394,680, 11.2%). Younger patients (age<40) contributed more to teledermatology service utilization (n=62,695, 83.2%) when compared to in-person services (n=1,329,218, 40.3%). Medicare and Private were larger payor contributors for in-person services (n=1,089,777, 25.2%;n=2712594, 62.6%) than for teledermatology services (n=8232, 5.4%;n=73940, 48.2%). Utilization by out-of-state patients was proportionally higher for teledermatology services (n=19,422, 14.6%) compared to in-person services (n=580,358, 4.2%). Conclusions: Teledermatology services may reach and benefit certain populations (females, younger patients, non-White races, out-of-state patients) more so than others.