ABSTRACT
In the midst of the COVID-19 pandemic, new requirements for clean air supply are introduced for heating, ventilation, and air conditioning (HVAC) systems. One way for HVAC systems to efficiently remove airborne viruses is by filtering them. Unlike disposable filters that require repeated purchases of consumables, the electrostatic precipitator (ESP) is an alternative option without the drawback of reduced dust collection efficiency in high-efficiency particulate air (HEPA) filters due to dust buildup. The majority of viruses have a diameter ranging from 0.1 μm to 5 μm. This study proposed a two-stage ESP, which charged airborne viruses and particles via positive electrode ionization wire and collected them on a collecting plate with high voltage. Numerical simulations were conducted and revealed a continuous decrease in collection efficiencies between 0.1 μm and 0.5 μm, followed by a consistent increase from 0.5 μm to 1 μm. For particles larger than 1 μm, collection efficiencies exceeding 90% were easily achieved with the equipment used in this study. Previous studies have demonstrated that the collection efficiency of suspended particles is influenced by both the ESP voltage and turbulent flow at this stage. To improve the collection efficiency of aerosols ranging from 0.1 μm to 1 μm, this study used a multi-objective genetic algorithm (MOGA) in combination with numerical simulations to obtain the optimal parameter combination of ionization voltage and flow speed. The particle collection performance of the ESP was examined under the Japan Electrical Manufacturers' Association (JEMA) standards and showed consistent collection performance throughout the experiment. Moreover, after its design was optimized, the precipitator collected aerosols ranging from 0.1 μm to 3 μm, demonstrating an efficiency of over 95%. With such high collection efficiency, the proposed ESP can effectively filter airborne particles as efficiently as an N95 respirator, eliminating the need to wear a mask in a building and preventing the spread of droplet infectious diseases such as COVID-19 (0.08 μm–0.16 μm). © 2023 by the authors.
ABSTRACT
Background: Previous studies have demonstrated promising serologic responses in PLWH receiving a third dose of vaccine against SARS-CoV-2. However, real-world clinical effectiveness, especially during the pandemic caused by B.1.1.529 variant, remains less investigated. Method(s): PLWH seeking HIV care at our hospital from 2021/6 to 2022/6 were included and advised to receive the third dose of COVID-19 vaccine. Individuals were excluded from this study if they had been previously diagnosed with COVID-19. Different types of COVID-19 vaccines were available in the vaccination program, including BNT162b2, mRNA-1273 (either 50 or 100 mug), MVC-COV1901 and NVX-CoV2373 vaccines. PLWH were screening for the occurrence of COVID-19 through the reporting system of notifiable diseases of Taiwan CDC, and were tested for anti-nucleocapsid (anti-N) IgG every 1 to 3 months. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, occurrence of SARS-CoV-2 infection, seroconversion of anti-N IgG, death, or loss to follow-up, whichever occurred first. Result(s): 1,496 PLWH were included: 631 (42.2%) receiving 100 mug mRNA-1273 vaccine, 468 (31.3%) 50 mug mRNA-1273 vaccine, and 328 (21.9%) BNT162b2 vaccine, 65 (4.3%) MVC-COV1901 vaccine, and 4 (0.3%) NVX-CoV2373 vaccine for the third dose of SARS-CoV-2 vaccination. 297 (19.9%) PLWH were diagnosed with COVID-19 during the follow-up period, including 92 (14.6%) who received 100 mug mRNA-1273, 111 (23.7%) 50 mug mRNA-1273, 79 (24.1%) BNT162b2 and 15 (21.7%) either MVC-COV1901 or NVX-CoV2373;in addition, 98 PLWH had seroconversion of anti-N IgG during follow-up, including 23, 50, 19 and 6 PLWH who received 100 mug mRNA-1273, 50 mug mRNA-1273, BNT162b2, and either MVC-COV1901 or NVX-CoV2373, respectively. Similar rates of new infection with SARS-CoV-2 or seroconversion of anti-N IgG were demonstrated regardless the vaccine type of the third dose (log-rank test, p=0.46). Factors associated with a diagnosis of SARS-CoV-2 infection and seroconversion of anti-N IgG included an age >50 years (aOR, 0.67;95% CI, 0.49-0.91) and newly infected with hepatitis C virus (HCV) (aOR, 1.41;95% CI, 1.09-1.83). Conclusion(s): Our study demonstrated that clinical effectiveness of the third dose of different vaccines available to PLWH was similar in preventing SARSCoV- 2 infection or seroconversion of anti-N IgG Taiwan. PLWH aged less than 50 years and those with newly diagnosed HCV infection were at higher risk of acquiring COVID-19. Kaplan-Meier survival curve for acquiring COVID-19 or seroconversion of anti-N IgG in PLWH receiving different COVID-19 vaccination of the third dose (log-rank test, 4 groups, p = 0.46).
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This article seeks to analyse how the aviation market is influenced by political policies. It begins by introducing the background of aviation regulation and the negotiations that have taken place between Taiwan and China over the past decades. It reviews what happened during the past decades, in particular the Cross-Strait Air Transport Agreement reached between Taiwan and China in January 2005. It also highlights the restricting factors of Cross-Strait aviation development and define the problems related to air freedoms. It goes on to measure the dependency degree that Taoyuan Airport relied on Chinese Airports in recent years. Finally, the impact on cross-strait aviation market due to Chinese political policies and the influence on air routes as a consequence of China military drills have been analysed. It concludes that the increased routes of direct flights have attracted Taiwanese passengers to transfer via Chinese airports to the US and Europe. However, the limitation of Chinese passengers to travel to Taiwan since 2019 and the spread of COVID-19 from 2020, destinations of Cross-Strait direct flights have reduced from sixty-one to four. The military drills in August 2022 also severely deteriorated the relation of the two sides. It seems that the development of the Cross-strait aviation market has gone back to the drawing board after fifteen years of success due to the current circumstances. From the case of Taiwan and China, the aviation market is indeed significantly influenced by the political policies. © 2022 Elsevier B.V.. All rights reserved.
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Background: Geriatric patients with COVID-19 have had poor clinical outcomes globally, especially during the first wave of the pandemic. In Taiwan, the first wave of the COVID-19 pandemic occurred from May to July 2021. This retrospective study aimed to compare the characteristics and outcomes between geriatric and younger patients with COVID-19 infection. Methods: A total of 257 confirmed COVID-19 cases who were hospitalized from May to June 2021 were included. Their characteristics and outcomes, including in-hospital mortality, use of mechanical ventilation, and hospital stay, were collected for analysis. Results: There were 98 elderly patients (aged >= 65 years, median, 72.5 (interquartile range, 69.0-78.0) years) and 159 younger patients (aged < 65 years, median 55.0 (46.0-60.0) years). The elderly patients had a significantly higher Charlson comorbidity score (4.0 (3.0-5.0) vs. 1.0 (1.0-2.0), p < 0.001), and significantly higher D-dimer, procalcitonin, ferritin, and creatinine levels, but lower albumin level than the younger patients. The elderly group also had higher in-hospital mortality (7.1% vs. 1.9%, p < 0.05), were more likely to develop severe disease (83.7% vs. 67.9%, p < 0.01), and had a longer hospital stay (15.0 (11.0-23.0) vs. 12.0 (9.0-16.5) days, p < 0.001). Nevertheless, the elderly patients did not have a higher risk of using high-flow nasal cannulas (17.3% vs. 15.1%, p = 0.63) or mechanic ventilation (23.5% vs. 17.0%, p = 0.20). Conclusion: Elderly COVID-19 patients had significant higher risks of severe disease, mortality, and lon-ger duration of hospitalization, possible due higher rates of comorbidities and pro-inflammatory status. Copyright (c) 2022, Taiwan Society of Geriatric Emergency & Critical Care Medicine.
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Background: Coronavirus disease 2019 (COVID-19) can cause acute respiratory failure and acute respiratory distress syndrome (ARDS). The prone position (PP) is widely used in patients with severe hypoxemia due to ARDS as it improves oxygenation. The aim of this study was to investigate whether improvements in gas exchange and lung mechanics with the PP were associated with survival in ventilated COVID-19 patients. Methods: Fourteen ventilated patients who were placed in the PP were included from May to June 2021. Clinical manifestations and lung mechanics parameters were collected. Results: The overall intensive care unit (ICU) mortality rate was 42.9%. Nonsurvivors were older (p = 0.014) and had higher Charlson comorbidity index (2.1 +/- 1.5 vs. 4.8 +/- 2.4, p = 0.035) and Sepsis-related Organ Failure Assessment (SOFA) (3.3 +/- 1.0 vs. 7.3 +/- 3.5, p = 0.019) scores compared to survivors. There was no difference in PaO2/FiO(2) (P/F ratio) at baseline between the survivors and nonsurvivors. The improvement in P/F ratio (p = 0.0037) and reduction in driving pressure (Pdrive) (p = 0.046) on the second day after first PP were correlated with lower mortality. Significant predictors of successfully stopping prone treatment included a reduction in Pdrive at the first hour, lower tidal volume (Vt) at the fourth hour, and P/F ratio improvement on the second day after PP. Conclusion: Improvement in P/F ratio and reduction in driving pressure on the second day after PP were correlated with reduced mortality. Three parameters could predict successful resumption of the supine position. Copyright (c) 2022, Taiwan Society of Geriatric Emergency & Critical Care Medicine.
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As one of the "Three Drugs Three Prescriptions" anti-COVID-19 traditional Chinese medicine, Jinhua Qinggan granules (JHQG) has been proved to have clear clinical effects. With complex medicinal flavors and ingredients, there is no systematic research report on chemical composition in vivo or in vitro. An ultrahigh pressure liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF/MS) method was developed in this study to identify the components of the anti-COVID-19 traditional Chinese medicine JHQG granules. Analyze the collected rat plasma samples after administration and explore the exposed components in rats within 8 hours after intragastric administration. Preliminary pharmacokinetic analysis was then performed on this basis. Through UPLC-QTOF/MS analysis and verification by standard products, a total of 77 chemical components in JHQG formula have been identified, among which 22 compounds were highly exposed in vivo, mainly derived from three medicinal materials of honeysuckle, scutellaria and forsythia. Through the assessment of the blood drug concentration by the compartment model, 6 PK parameters of 4 high-exposure chemical components have been obtained, clarifying the metabolic characteristics of the main exposed components in JHQG briefly. The method is simple, efficient, sensitive and accurate and provides research basis to the clarification of the pharmacodynamics material basis and mechanism of JHQG, which has certain reference significance for the basics and applications research of the traditional Chinese medicine prescriptions in fighting the SARS-CoV-2.
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With the recent outbreak of COVID-19, ultrasound is fast becoming an inevitable diagnostic tool for regular and continuous monitoring of the lung. However, lung ultrasound (LUS) is unique in the perspective that, the artefacts created by acoustic wave propagation is aiding clinicians in diagnosis. In this work, a novel approach is presented to extract acoustic wave propagation driven features such as acoustic shadows, local phase-based feature symmetry, and integrated backscattering to automatically detect the pleura and to aid a pretrained neural network to classify the severity of lung infection based on the region below pleura. A detailed analysis of the proposed approach on LUS images over the infection to full recovery period of ten confirmed COVID-19 subjects across 400 videos shows an average five-fold cross-validation accuracy, sensitivity, and specificity of 97%, 92%, and 98% respectively over randomly selected 5000 frames. The results and analysis show that, when the input dataset is limited and diverse as in the case of COVID-19 pandemic, an aided effort of combining acoustic propagation-based features along with the gray scale images, as proposed in this work, improves the performance of the neural network significantly even when tested against a completely new data acquisition. © 2021 IEEE.
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Due to the COVID-19 pandemic, citizens of the United Kingdom were required to stay at home for many months in 2020. In the weeks before and months following lockdown, including when it was not being enforced, citizens were advised to stay at home where possible. As a result, in a megacity such as London, where long-distance commuting is common, spatial and temporal changes to patterns of water demand are inevitable. This, in turn, may change where people's waste is treated and ultimately impact the in-river quality of effluent receiving waters. To assess large scale impacts, such as COVID-19, at the city scale, an integrated modelling approach that captures everything between households and rivers is needed. A framework to achieve this is presented in this study and used to explore changes in water use and the associated impacts on wastewater treatment and in-river quality as a result of government and societal responses to COVID-19. Our modelling results revealed significant changes to household water consumption under a range of impact scenarios, however, they only showed significant impacts on pollutant concentrations in household wastewater in central London. Pollutant concentrations in rivers simulated by the model were most sensitive in the tributaries of the River Thames, highlighting the vulnerability of smaller rivers and the important role that they play in diluting pollution. Modelled ammonia and phosphates were found to be the pollutants that rivers were most sensitive to because their main source in urban rivers is domestic wastewater that was significantly altered during the imposed mobility restrictions. A model evaluation showed that we can accurately validate individual model components (i.e., water demand generator) and emphasised need for continuous water quality measurements. Ultimatly, the work provides a basis for further developments of water systems integration approaches to project changes under never-before seen scenarios.
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Due to the COVID-19, the Ministry of Education of China announced that the 2020 spring semester will be postponed, on-site classes should be cancelled and schools should give online classes instead. It's the first time that online classes have been given priority to higher education, which is a new challenge to both schools and online learning platforms. It's necessary to carry out stable and efficient IT solutions to secure the smooth process of online classes. This paper takes South China University of Technology as an example to put forward some IT solutions and ways of improving teaching quality of online classes for higher education during COVID-19 pandemic.