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With the expansion of novel coronavirus pneumonia's influence on the world, people's dependence on infrared thermometer guns is increasing. In order to improve the measurement accuracy of the infrared temperature measuring gun and meet the requirements of rapid and accurate measurement of human body temperature, the core components for the infrared temperature measuring gun are developed and prepared in this paper. The film fogging phenomenon caused by the anisotropy of metal germanium and semiconductor properties is analysed and solved by measuring the atomic force microscope image and infrared spectrum of the film, the 5.5-micron infrared filter with high transmittance and good film quality was prepared by electron beam evaporation, resistance evaporation and ion source assisted deposition.
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This study examined how college students in a medical school in China engaged in learning in asynchronous online learning environments during the COVID-19 health crisis. A quasi-experimental design approach was employed to compare if a class of students had better learning outcomes and developed systems thinking when asynchronous discussion forums incorporated an inquiry-based pedagogical approach in one unit, whereas the other unit followed a traditional instructor-led approach. In sum, 25 junior students participated in this study. Quantitative results show that the students had statistically significant higher assessment scores and improved systems thinking when the unit incorporated the inquiry-based pedagogical approach. Qualitative findings also demonstrated how students engaged in learning and how the instructor scaffolded students' inquiries and learning. Practical implications for instructors' teaching online courses are also discussed. © The author(s) 2023.
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The filtration efficiency deterioration over operating time due to exposure to particles, organic solvents and other factors is an obvious defect of electret filter, especially during the coronavirus pandemic. Electrostatic enhanced method has been proposed as a promising way to improve the filtration efficiency and service time of electret filters without increasing the pressure drop. In this work, the effect of discharge electrode structure and operation mode of the electrostatic enhanced structure(EES) on the filtration efficiency of commercial pleated electret filters were studied firstly, then the EES was installed in a special designed prototype air purifier, two key indicators of air purifiers(clean air delivery rate (CADR) and cumulate clean mass (CCM)) were tested to evaluate the actual performance improvement of electret filters by the electrostatic enhanced method. It was found that the discharge electrode structure had significant influence on the filtration efficiency and multi-wire array electrode was more suitable for the discharge electrode to pleated filter to ground mesh structure used in this paper. The decayed electrostatic charges of pleated electret filter cannot be recharged again through the EES in actual operation condition. The filtration efficiency improvement of the test pleated electret filters was dominantly contributed by particle charging. The filter polarizing induced by the external electric field was helpful in increasing the filtration efficiency when the particles were charged while its effect on uncharged particles was almost negligible. Besides, the actual performance of the prototype air purifier indicated that the EES can alleviate the filtration efficiency deterioration of test electret filters and extend the service life of H11 and H13 filters by more than 3 and 1.5 times respectively according to the CCM test results. © 2023 IOP Publishing Ltd.
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With the expansion of novel coronavirus pneumonia's influence on the world, people's dependence on infrared thermometer guns is increasing. In order to improve the measurement accuracy of the infrared temperature measuring gun and meet the requirements of rapid and accurate measurement of human body temperature, the core components for the infrared temperature measuring gun are developed and prepared in this paper. The film fogging phenomenon caused by the anisotropy of metal germanium and semiconductor properties is analysed and solved by measuring the atomic force microscope image and infrared spectrum of the film, the 5.5-micron infrared filter with high transmittance and good film quality was prepared by electron beam evaporation, resistance evaporation and ion source assisted deposition. © 2022 IEEE.
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Recently, an increasing number of companies have encountered random production disruptions due to the COVID-19 pandemic. In this study, we investigate a two-stage supply chain in which a retailer can order products from a low-price ("cheap”) unreliable supplier (who may be subject to an uncertain production disruption and partially deliver the order) and an "expensive” reliable supplier at Stage 1 and a more "expensive” backup supplier at Stage 2. If the disruption happens, only the products that were produced before the disruption time can be obtained from the unreliable supplier. It is found that in the case with imperfect demand information updating, the unreliable supplier is always used while the reliable supplier can be abandoned. The time-dependent supply property of the unreliable supplier reduces the retailer's willingness of adopting the dual sourcing strategy at Stage 1, compared with the scenario with all-or-nothing supply. Different from the case with imperfect demand information updating, either the reliable or unreliable supplier can be abandoned in the case with perfect demand information updating. We derive the optimal ordering decisions and the conditions where single sourcing or dual sourcing is adopted at Stage 1. We conduct numerical experiments motivated by the sourcing problem of 3M Company in the US during the COVID-19 and observe that the unreliable supplier is more preferable when the demand uncertainty before or after the emergency order is higher. Interestingly, the retailer tends to order more from the unreliable supplier when the production disruption probability is larger in some cases. © 2022 The Author(s)
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Aim To determine the antiviral and anti-inflammatory effects of the recommended prescription for COVID-2019-lung-spleen qi deficiency(4-1)against in vitro infection of SARS-CoV-2 and common coronaviruses.Methods The main chemical substances of 4-1 were analyzed by LC-MS.The toxicity and antiviral effects of of 4-1 were detected by MTT and by CPE assay, respectively.The viral loads in cell supernatant and the expression of inflammatory factors induced by viral infection were determined by qRT-PCR.Results The recommended prescription 4-1 contained 94 chemical compounds, including flavonoids, steroids, sesquiterpenoids, and so on.The range of selection indexes for SARS-CoV-2 and common coronaviruses was 8.44+/-0.49~52.26+/-2.3.This prescription could inhibit the proliferation of SARS-CoV-2, the expression of ACE2 and S mRNA, and down regulate IL-1alpha and CCL-5/RANTES at 10, 5, and 2.5 g*L-1 doses.Further, at doses of 20, 10 and 5 g*L-1, it could inhibit the proliferation of three common coronaviruses and suppress the overexpression of IL-6, CXCL-8/IL-8, CXCL-10/IP-10, TNF-alpha, IFN-alpha, CCL-2/MCP-1, MIG and CCL-5/RANTES induced by OC43/229E infection.The inhibitory effects were dose-dependent.Conclusions The prescription 4-1 has antiviral and anti-inflammation effects against multiple coronaviruses.This study provides the research basis for the treatment of common respiratory viral infections and emerging infectious diseases such as COVID-19 by using traditional Chinese medicine. Copyright © 2022 Publication Centre of Anhui Medical University. All rights reserved.
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To explore the early stage spatial-temporal characteristics and to assess the factors of atmospheric pollution that may affect the development of coronavirus disease 2019（COVID-19）outbreak in the Chinese Mainland in 2020，we collected the daily new cases of COVID-19 in the Municipalities and Provinces from the websites of National and Provincial Health Commission of China. The spatiotemporal characteristics of COVID-19 epidemic were studied using autocorrelation analysis and trend analysis. The Spearman's correlation coefficient for ranked data and generalized additive model were used for risk assessment of air pollutants affecting the COVID-19 epidemic of Hubei Province. Daily new cases of COVID-19 in the Chinese Mainland totaled 39 877 from January 20th to February 9th of 2020. The global Moran index values of these three weeks were 0.249，0.307 and 0.297（P<0.01），respectively. There was a significant clustering phenomenon. The high incidence regions included Hunan Province，Guangdong Province，Jiangxi Province，Zhejiang Province，Anhui Province and Jiangsu Province. The epidemic hot spots were basically distributed in the area from 108° 47'-123° 10' E to 25° 31'-35° 20' N. Daily new cases of COVID-19 in Hubei Province was positively correlated with daily average concentrations of PM10，NO2 and O3 pollutants（ρ =0.515，0.579 and 0.536，P<0.05）. The lag effects of air pollutions were existed. The relative risk（RR）values of PM2.5and PM10 reached to maximum with lag0，the RR value of NO2 reached to maximum with lag4，and the RR value of O3 reached to maximum with lag 0~1. We estimated that a 10 μg/m3 increase in day-before NO2 daily average concentration was associated with a 32.745% （95% Confidence Interval（CI）：11.586%-57.916%）excess risk（ER）of daily new cases of COVID-19. And NO2 had a significant impact on daily new cases of COVID-19. When NO2 was introduced to PM2.5and PM10 separately，for every 10 μg/m3 rise in NO2 daily average concentration，the ER of daily new cases of COVID-19 was 23.929%（95% CI：4.705%-46.682%）and 24.672%（95% CI：5.379%-47.496%），respectively. The study showed that the southeast was the main spread direction in the early stage of COVID-19 outbreak in the Chinese Mainland in 2020. Reducing the atmospheric concentration of nitrogen dioxide in epidemic hot spots has a positive effect on epidemic prevention and control. © 2022 Journal of Zhongshan University. All rights reserved.
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Coronavirus disease 2019 (COVID‑19) caused by 2019 novel coronavirus (2019‑nCoV), has constituted a major worldwide public health event. At present, vaccination against COVID‑19 is being actively promoted in order to establish a population immune barrier. Here consensus guidance is given on the safety and efficacy of COVID‑19 vaccination in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). Overall, the risk of 2019‑nCoV infection in MS or NMOSD patients is not increased than that in the general population. The existing vaccines against COVID‑19 do not cause vaccine‑derived infection in patients receiving any immune interventions, although the effectiveness of vaccine may be reduced in some cases (such as the use of sphingosine‑1‑phosphate receptor modulator or B‑cell depletion agent). There is no sufficient evidence that vaccination will aggravate MS or NMOSD, or directly lead to disease recurrence. Therefore, after fully informed consent and pre‑assessment of vaccination‑related risk, it should be recommended that MS and NMOSD patients with stable disease control be vaccinated against COVID‑19.
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With the rapid development of modern science and technology, the application of infrared (IR) optical thin films is increasingly widespread, including in aerospace, autonomous driving, military development, and the fight against Coronavirus Disease 2019 (COVID-19), in which thin film devices play an important role. Similarly, with the improvement of user requirements, the precision requirements for the preparation of optical films are also developing and improving. In this paper, the IR optical thickness monitoring system is studied with the noble algorithm introducing the phase-locked amplifier current and single film reflectivity coefficient. An optical control system is developed to monitor the IR thin film accurately, which aids the IR narrow-band filter film research.
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Objective: To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. Methods: The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. Results: From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2â¶1 (114â¶57). The median age M (Q1, Q3) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (P<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median Ct values M (Q1, Q3) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene Ct value between the partially vaccinated group and the fully vaccinated group. Conclusions: During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.
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COVID-19 , Nucleic Acids , Beijing , COVID-19/epidemiology , COVID-19 Vaccines , Female , Humans , Male , SARS-CoV-2ABSTRACT
The ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed an extraordinary threat to global public health, wealth, and well-being. As the carriers of human life and production, infrastructures need to be upgraded to mitigate and prevent the spread of viral diseases. Developing multifunctional/smart civil engineering materials to fight viruses is a promising approach to achieving this goal. In this Perspective, a basic introduction on viruses and their structure is provided. Then, the current design principles of antiviral materials and structures are examined. Subsequently, the possibility of developing active/passive antiviral civil engineering materials (including cementitious composites, ceramics, polymers, and coatings) is proposed and envisioned. Finally, future research needs and potential challenges to develop antiviral civil engineering materials are put forward. The proposed strategies to develop multifunctional/smart antiviral civil engineering materials will aid in the construction of smart infrastructures to prevent the spread of viruses, thus improving human life and health as well as the sustainability of human society.
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Objective To systematically review the safety of different types of COVID-19 vaccines in the population. Methods Web of Science, PubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and CBM databases were electronically searched to collect randomized controlled trials (RCTs) which reported safety of COVID-19 vaccines in population. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by using RevMan 5.4 software. Results A total of 5 RCTs involving 2 431 subjects were included. The results of the meta-analysis showed that COVID-19 vaccines developed more fever symptoms than placebo (RR=2.21, 95%CI 1.38 to 3.54, P=0.000 9). However, there was no significant difference in the incidence of adverse reactions (RR=1.28, 95%CI 0.96 to 1.70, P=0.10), injection site adverse reactions (RR=1.47, 95%CI 0.65 to 3.36, P=0.36) and systemic adverse reactions (RR=0.96, 95%CI 0.78 to 1.17, P=0.66) between two groups. Conclusions Current evidence shows that COVID-19 vaccines are sufficiently safe. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusions. © 2021 West China University of Medical Science. All rights reserved.
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During the recent COVID-19 pandemic, wearing face masks has become the simplest and most effective way to block the spread of the disease. However, after people wear masks, thousands of tons of medical waste caused by used disposable masks is being generated every day in the world, causing great pressure on the environment. Herein, polymer composites completely derived from waste are manufactured by simple melt blending of disposable mask fragments (mask polypropylene, short for mPP) and discarded loofah sponge (LS). LS was used as a reinforcing agent for the composites because of its unique micron channel structure. The crystalline structure and the mechanical enhancement effect of the composites were investigated. LS powders played a role in promoting the crystallization of mPP by expediting the crystalline nucleation, leading to an improvement in the amount of crystalline nuclei. After being incorporated within the mPP with high fluidity, the LS fiber changing from hollow to solid provides reinforcement for composite materials. With 12 wt % LS loading, the tensile strength of the composites was increased by 326%. The findings may open a way for high-value utilization of disposable masks. © 2021 American Chemical Society.
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OBJECTIVES: We aimed to (1) assess parental hesitancy about category A (Expanded Program on Immunization (EPI)) and B (non-EPI) vaccines, (2) assess parental willingness for COVID-19 and influenza vaccinations, and (3) explore the association of vaccination hesitancy of parents and healthcare workers (HCWs). METHODS: The study was performed in Wuxi, eastern China between 21 September 2020 and 17 October 2020. Parents of children aged <18 years and HCWs were recruited from the selected immunization clinics. Vaccine hesitancy was assessed using the Strategic Advisory Group of Experts (SAGE) vaccine hesitancy survey (VHS) by summing the total score for 10 items (maximum 50 points). RESULTS: A total of 3009 parents and 86 HCWs were included in the analysis. The category A VHS scores were significantly higher than the category B VHS scores (p = 0.000). Overall, 59.3% and 52.4% of parents reported willingness to avail COVID-19 and influenza vaccination for their children, respectively;51.2% of the HCWs wanted to be vaccinated against COVID-19. Parental category B VHS scores were associated with HCW category B VHS scores (r = 0.928, p = 0.008). CONCLUSIONS: In China, parents are more hesitant about category B vaccines than category A vaccines. More than 40% of parents showed hesitancy and a refusal to use COVID-19 and influenza vaccines.
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Objectives: The aim of this study was to investigate coronavirus disease 2019 (COVID-19) epidemic characteristics in Africa and provide some references to prevent pandemic. Methods: We collect information of the laboratory-confirmed case of COVID-19 that has been reported since April 28, 2020 in Africa, describe the epidemic characteristics in different regions of Africa, and predict the spread trend. Results: (1) There are 35,309 COVID-19 cases and 1,522 deaths in 54 African countries. Both case amount and death toll in Northern Africa are higher than those in other African regions, whereas the case fatality rate (CFR) in Africa is lower than that of the world. (2) Among the 54 countries in Africa, 39 of them (72.22%) report confirmed cases between 1 and 499. (3) In total, 596,146 tests have been conducted in 35 countries, and 28,271 patients have been confirmed, with a positive rate of 4.74%. However, there are only 335 tests (interquartile range: 145.5–874) for every 1 million people in Africa. (4) The number of infection cases will increase to around 150,000 at the end of May according to our model. Conclusion: In Africa, COVID-19 spreads faster while with a relatively lower CFR, and it may be related to higher young people ratio. In addition, test intensity of COVID-19 is obviously insufficient in Africa. © Copyright © 2020 Wang, Dong, Zhao, Gao, Wang, Yu, Xu and Chai.
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Porcine epidemic diarrhea, a disease caused by porcine epidemic diarrhea virus (PEDV), results in large economic losses to the global swine industry. To manage this disease effectively, it is essential to detect PEDV early and accurately. We developed a sensitive and accurate droplet digital PCR (ddPCR) assay to detect PEDV. The optimal primer-to-probe concentration and melting temperature were identified as 300:200 nM and 59.2°C, respectively. The specificity of the ddPCR assay was confirmed by negative test results for common swine pathogens. The detection limit for the ddPCR was 0.26 copies/µL, which is a 5.7-fold increase in sensitivity compared to that of real-time PCR (rtPCR). Both ddPCR and rtPCR assays exhibited good linearity, although ddPCR provided higher sensitivity for clinical detection compared to that of rtPCR. Our ddPCR methodology provides a promising tool for evaluating the PEDV viral load when used for clinical testing, particularly for detecting samples with low-copy viral loads.
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Coronavirus Infections/veterinary , Polymerase Chain Reaction/veterinary , Porcine epidemic diarrhea virus/isolation & purification , Swine Diseases/diagnosis , Viral Load/veterinary , Animals , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Polymerase Chain Reaction/methods , Sensitivity and Specificity , Sus scrofa , Swine , Swine Diseases/virologyABSTRACT
OBJECTIVE: Patients with cancer are usually immunosuppressive and susceptible to COVID-19 infection. Asymptomatic COVID-19 cases are infective and cannot be identified by symptom-based screening. There is an urgent need to control virus spread by asymptomatic carriers at cancer centres. We aim to describe the characteristics, screening methods, and outcomes of cancer patients with asymptomatic COVID-19 infection and to further explore anti-tumour treatment for this population. PATIENTS AND METHODS: We reviewed patients with cancer who were admitted to Hubei Cancer Hospital in Wuhan from February 1, 2020, to April 4, 2020. We collected demographic data, laboratory findings, treatment information, nucleic acid and serum test results, chest computed tomography (CT) information and survival status of cancer patients diagnosed with asymptomatic COVID-19 infection. RESULTS: A total of 16 cancer patients with asymptomatic COVID-19 infection were confirmed. The most common cancer type was breast cancer. The blood cell counts of most patients were in the normal range. Lymphocytes of 100% of asymptomatic carriers were in the normal range. Thirteen (81.3%) patients were positive for virus-specific IgM antibodies, and three (18.8%) were positive by PCR; only one (6.3%) patient showed novel coronavirus pneumonia features on CT. Three (18.3%) patients died, and the cause of death was considered malignancy caused by delaying anti-tumour treatment. CONCLUSIONS: Our study shows that the lymphocytes of 100% of asymptomatic carriers were in the normal range. This result indicates that the host immunity of asymptomatic carriers is not significantly disrupted by COVID-19. Single PCR detection is not sufficient to screen among asymptomatic individuals, and a combination of PCR tests, serological tests and CT is of great importance. Unless the tumour is life-threatening or rapidly progressing, we advise restarting active anti-tumour therapy after PCR tests become negative.
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Asymptomatic Diseases/epidemiology , Cancer Care Facilities/statistics & numerical data , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Aged , Betacoronavirus , COVID-19 , China/epidemiology , Coronavirus Infections/complications , Female , Humans , Male , Middle Aged , Neoplasms/complications , Neoplasms/drug therapy , Pandemics , Pneumonia, Viral/complications , SARS-CoV-2 , Survival RateABSTRACT
The Nuclear Medicine Global Initiative was formed in 2012 by 13 international organizations to promote human health by advancing the field of nuclear medicine and molecular imaging by supporting the practice and application of nuclear medicine. The first project focused on standardization of administered activities in pediatric nuclear medicine and resulted in 2 articles. For its second project the Nuclear Medicine Global Initiative chose to explore issues impacting on access and availability of radiopharmaceuticals around the world. Methods: Information was obtained by survey responses from 35 countries on available radioisotopes, radiopharmaceuticals, and kits for diagnostic and therapeutic use. Issues impacting on access and availability of radiopharmaceuticals in individual countries were also identified. Results: Detailed information on radiopharmaceuticals used in each country, and sources of supply, was evaluated. Responses highlighted problems in access, particularly due to the reliance on a sole provider, regulatory issues, and reimbursement, as well as issues of facilities and workforce, particularly in low- and middle-income countries. Conclusion: Strategies to address access and availability of radiopharmaceuticals are outlined, to enable timely and equitable patient access to nuclear medicine procedures worldwide. In the face of disruptions to global supply chains by the coronavirus disease 2019 outbreak, renewed focus on ensuring a reliable supply of radiopharmaceuticals is a major priority for nuclear medicine practice globally.