Advances in particulate matter filtration: Materials, performance, and application

Air-borne pollutants in particulate matter (PM) form, produced either physically during industrial processes or certain biological routes, have posed a great threat to human health. Particularly during the current COVID-19 pandemic, effective filtration of the virus is an urgent matter worldwide. In this review, we first introduce some fundamentals about PM, including its source and classification, filtration mechanisms, and evaluation parameters. Advanced filtration materials and their functions are then summarized, among which polymers and MOFs are discussed in detail together with their antibacterial performance. The discussion on the application is divided into end-of-pipe treatment and source control. Finally, we conclude this review with our prospective view on future research in this area. (c) 2022 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Characterization and Source Apportionment of PM in Handan—A Case Study during the COVID-19

Handan is a typical city affected by regional particulate pollution. In order to investigate particulate matter (PM) characterization, source contributions and health risks for the general populations, we collected PM samples at two sites affected by a pollution event (12–18 May 2020) during the COVID-19 pandemic and analyzed the major components (SNA, OCEC, WSIIs, and metal elements). A PCA-MLR model was used for source apportionment. The carcinogenic and non-carcinogenic risks caused by metal elements in the PM were assessed. The results show that the renewal of old neighborhoods significantly influences local PM, and primarily the PM10;the average contribution to PM10 was 27 μg/m3. The source apportionment has indicated that all other elements came from dust, except Cd, Pb and Zn, and the contribution of the dust source to PM was 60.4%. As PM2.5 grew to PM10, the PM changed from basic to acidic, resulting in a lower NH4+ concentration in PM10 than PM2.5. The carcinogenic risk of PM10 was more than 1 × 10−6 for both children and adults, and the excess mortality caused by the renewal of the community increased by 23%. Authorities should pay more attention to the impact of renewal on air quality. The backward trajectory and PSCF calculations show that both local sources and short-distance transport contribute to PM—local sources for PM10, and short-distance transport in southern Hebei, northern Henan and northern Anhui for PM2.5, SO2 and NO2. © 2023 by the authors.

A microchamber-free and enzyme-free digital assay based on ultrabright fluorescent microspheres

Digital analysis is an effective single-molecule detection method and has attracted extensive attention in the field of bioassays. However, most digital assays require microchambers for signal compartmentalization. Herein, we developed a microchamber-free and enzyme-free digital assay by labeling paramagnetic beads directly with ultrabright fluorescent microspheres. In this assay, a DNA sandwich analysis was firstly performed on the bead to label a fluorescent microsphere. Then, the beads were loaded on the glass slide to form a monolayer film for signal readout. The whole analysis process does not require the participation of enzymes and the preparation of microchambers, which greatly simplifies the experimental steps and saves the costs. Furthermore, by introducing non-enzymatic hybridization chain reaction (HCR) and biotinylated DNA-conjugated gold nanoparticles (Au NPs-Bio), the capture efficiency and analytical sensitivity were improved. As a proof of concept, single-stranded DNA (ssDNA) of SARS-CoV-2 fragment was chosen as a model, and a detection limit of 1.5 fM was achieved. Spiked and recovery experiments on human serum and saliva samples validated the good performance of the proposed digital assay in real biological samples. The proposed assay provides a facile way of signal generation and readout for digital analysis. © 2023 Elsevier B.V.

MANUFACTURING OF THE ERIEDESCENT STERILIZING DEVICE

Beyond an exceptional human toll, one of the most evident impacts of the ongoing COVID-19 pandemic is that of disrupted supply chain dynamics. Lessons learned here might help ameliorate the ability of frontline workers to secure personal protective equipment (PPE) such as N95 filtering facepiece respirators (FFRs) to prevent similar issues in future pandemics. A related concern is FFR waste streams, and the ability to recycle N95s using chemical or physical germicidal methods would greatly contribute to lessening PPE scarcity and providing relief to overall supply chains for all essential services. Early in 2020, the U.S. Food and Drug Administration (FDA) issued official guidance for sterilizers, disinfectant devices, and air purifiers with regards to the COVID-19 pandemic as a public health emergency bulletin. This guidance provided nonbinding recommendations for PPE and FFR decontamination processes, involving a wide spectrum of chemical and physical methods of sterilization. Many of the sterilization methods employ high heat or utilize polar chemical disinfectants that can compromise either the physical structure or the electrostatic properties of FFR fibers, thus attenuating the overall protection provided to the frontline worker. Ultraviolet germicidal irradiation (UVGI) has been employed for nearly a century to sterilize instruments and whole environments. UVGI offers numerous advantages as it is transitory by nature, leaving no chemical residue on the treated artifact. UVGI is also rapid, and depending on illumination sources, UVGI can easily scale to provide coverage to large areas. Here we provide an analysis of the regulatory aspect related to the use of UVC devices and describe our engineered design of a cost-efficient sterilization chamber that utilizes UVC for decontamination. Our design stresses a low-cost price point to facilitate easy manufacture for not only rapid deployment but also minimal impacts on supply chains. The device is intended to be easy to use, without any specialized training, and thus targets the general public for sanitizing non-washable materials, including PPE, FFR and other potential fomites, including electronic devices of daily use, that otherwise might harbor bacterial, viral and fungal pathogens. Copyright © 2022 by ASME.

Neurological impact of COVID-19: Sub-acute brain microstructural alterations in self-isolated individuals

Objective: This study investigates the effects of COVID-19 on brain microstructure among those recently recovering from COVID-19 through self isolation. Background: Microstructural differences have previously been detected in comparisons of COVID-19 patients with controls, particularly in regions related to the olfactory system. The olfactory system is connected with the caudate, putamen, thalamus, precuneus, and cingulate regions. Design/Methods: Here we report diffusion magnetic resonance imaging (3 T Siemens MRI) findings from 40 patients (mean age: 43.7, 68% female) who self-isolated after testing positive for COVID (COV+), and 14 COVID negative (COV-) subjects (mean age: 43, 64% female) who had flu-like symptoms. This is part of the Canadian-based NeuroCOVID-19 study. Fractional anisotropy (FA), mean diffusivity (MD), mode of anisotropy (MO), free water fraction (F), tissue-specific FA (FAt) and tissue-specific MD (MDt) were obtained using data with b=700 and 1400 (DIPY free-water model). Regions of interest in the grey matter and white matter were delineated using FreeSurfer. Differences between groups were assessed using an analysis of variance (ANOVA), the Kruskal-Wallis Test and the Mann-Whitney Test, corrected for false-discovery rate of 0.05. Effect size (Cohen's d) was also computed (d>0.45 deemed large effect). Results: In the COV+ group, all three tests revealed decreased FA and FAt in the insula, and increased MD in the parstriangularis cortex. Increased FA and FAt in the cuneus (along with decreased MD) was also found. MD was reduced in COV+ in the temporal and supramarginal areas. MO was lower in COV+ in the insula and amygdala regions. Conclusions: In patients, higher MD with lower FA and MO suggest increased extracellular fluids, while lower MD with decreased FA and MO may suggest necrotic debris built up following inflammation. The cuneus and insula are involved in visual and taste processing, respectively. This study highlights the need to study neurological effects of COVID-19.

“Long-hauler ” impact of COVID-19 on brain microstructure: a 3-month follow-up study

Objective: This study investigates the chronic effects of COVID-19 on brain microstructure. Background: Microstructural differences have previously been detected in comparisons of COVID-19 patients with controls, particularly in the insula, cuneus, inferior temporal and anterior cingulate regions. Design/Methods: Here we report diffusion magnetic resonance imaging (3 T Siemens MRI) findings from 20 participants (mean age: 45.3, 55% female), both immediately after recovery and at a 3-month follow-up. Fractional anisotropy (FA), mean diffusivity (MD), mode of diffusivity (MO), free water fraction (F), tissue-specific FA (FAt) and tissue-specific MD (MDt) were obtained using DTI data with b=700 and 1400 (DIPY free-water model). Regions of interest in the grey matter and white matter were delineated using FreeSurfer. To assess differences between baseline and follow-up, a paired t-test, the Wilcoxon Test and Friedman Test were performed, corrected for false-discovery rate of 0.05. Effect size (Cohen's d) was also computed (d>0.45 deemed large effect). Results: All three tests revealed decreased F in the hippocampus and decreased MD in the parahippocampal region of the WM at follow-up. In the GM, F was increased in the medial orbitofrontal region. In the WM, MD was increased in the paracentral region and MDt was increased in the parahippocampal and lateral orbitofrontal regions. Conclusions: These results suggest that microstructural abnormalities persist following recovery. Increased extracellular fluid (i.e. F and MD) in the frontal lobe suggest spreading of COVID-19 impact, while decreased F and MD in the hippocampal region suggest debris accumulation as part of the inflammatory process. None of the regions affected in sub-acute COVID-19 appear to fully recover within three months.

Improving Social Responsibility of Intelligent Engineering under COVID-19

Since 2019, COVID-19 has seriously affected many industries of the economy. It is a major emergency risk event, which has caused a huge impact on all kinds of projects implemented by engineering enterprises. Nowadays, more and more engineering have introduced ecological concepts and achieved remarkable results in the fields of energy conservation, environmental protection, and renewable energy utilization. In the current global situation, how to improve the sustainable development of intelligent engineering has become a new problem. The paper explains the social responsibility connotation of intelligent engineering by using the framework proposed by ISO 26000. It puts forward that the expectations of employees, shareholders, communities, consumers, supply chains, governments, and other stakeholders should be fully taken into account in the whole process of the project. By analyzing the problems of intelligent engineering on social responsibility, it provides some suggestions from the seven core subjects of ISO 26000, such as organizational governance, human rights, labor practices, the environment, fair operating practices, consumer issues, and community involvement and development.

Combating COVID-19 and workplace safety among non-healthcare workers in Hong Kong, Nanjing and Wuhan, China

Introduction: We aimed to develop a new tool to measure workplace safety towards infection control and prevention of COVID-19 for non-healthcare workers in China. Methods and materials: During 07/2020 to 04/2021, 6684 non-healthcare workers were recruited from Hong Kong, Nanjing and Wuhan of China and responded a standard questionnaire of prevention measures towards infectious control. The workplace safety towards SARS-Cov-2 and COVID-19 index (WSSC index) was developed and validated using exploratory factor analysis and confirmatory factor analysis. Robustness of the index was verified by the uptake of SARS-Cov-2 testing. Results: Fourteen variables were identified in the WSSC index, with three sub-domains of workplace’s implementation of OSH prevention measures, company’s OSH management and worker’s prevention behavior and awareness. The new WSCS index obtained a good internal consistency reliability (Cronbach's alpha coefficients: 0.76-0.91), good composite reliability (composite reliability: 0.70-0.95) and satisfactory fit of the model (GFI=0.95;SRMR=0.05;RMSEA=0.07). Workers with higher scores of the WSCS index were more likely to uptake virus testing. Conclusions: This novel index is a validated tool to horizontally measure the performance of workplace safety towards SARS-Cov-2 & COVID-19 among non-healthcare workers across different industries and cities of China. Whether the tool is valid for longitudinally monitoring is under testing.

Levels of anxiety and depression and the perceived risk of COVID-19 at work

Introduction Workers who frequently contact to public or provide close-contact service may have higher anxiety and depression levels, as they may be worried about getting infected with the coronavirus at work. Objectives To examine the association of perceived risk of COVID-19 at work (including contact with people and close contact to public) with anxiety and depression levels among non-healthcare worker, taking perceived effectiveness of company's preventive measures into account. Methods This is a multi-city cross-sectional study in Hong Kong, Nanjing and Wuhan. We recruited 7391 non-healthcare workers who were aged>18 during 07/2020-04/2021. We used standardized questionnaire to collect sociodemographic, job-related information and their satisfaction of effectiveness of company's preventive measures. Participants' frequency of contact and close contact to public were collected and classified into occasionally, sometimes and often, and their anxiety and depression levels were measured using DASS-21. We performed multinomial logistic regression models to examine the association of frequency of contact and close contact to public with anxiety and depression levels. Path models were developed to analyze the potential modification of perceived effectiveness of company's preventive measures on these associations. Results Compared with workers with occasional contact to population, workers with sometimes contact were associated with severe anxiety (AOR=1.59, 95%CI=1.27-1.99). The AOR for workers with often close contact to public compared with no contact were 1.53 (95%CI= 1.25-1.87) for severe anxiety, and 1.43 (95%CI=1.14-1.79) for severe depression. Additionally, according to path analysis, the indirect path between contact or close contact to public and anxiety/depression were modified by perceived effectiveness of company's preventive measures. Conclusion Workers with frequent contact with people or close contact to public was associated with worse anxiety and depressive symptoms. Companies should consider effective and sustainable measures in mitigating the risk and thereby reducing employees' anxiety and depression levels during the COVID-19 pandemic.

The Chinese Way of Reforming Global Economic Governance: An Analysis of China’s Rising Role in the Group of Twenty (G-20)

Since the Global Financial Crisis engulfed much of the world in 2008, the Group of Twenty (G-20) has emerged as the self-acclaimed “premium forum” for international economic cooperation and policy coordination. The ascendency of G-20, of which China is a part, indicates the world’s preference for a more inclusive and informal economic governance model, moving away from the relatively restrictive Group of Seven (G-7) and the legalized Bretton Woods settings. This article analyzes China’s participation and increasingly critical role in the G-20. China’s main priorities in relation to the G-20 evolved over time. The initial focuses on containing financial contagion and reforming Bretton Woods institutions were followed by attempts to resolve bilateral trade issues with the US and to fight the Coronavirus Disease 2019 (COVID-19) pandemic. China aspires to transform the G-20 from an ad hoc crisis management platform to one promoting proactive long-term global policy cooperation, partly in support of “a community with shared future for humanity” and the Belt and Road Initiative. However, public distrust of international economic interdependence, populist backlash against neoliberal globalization, as well as geopolitical, ideological, technological tussles between China and the West collectively present significant challenges to the G-20. © 2021 Taylor & Francis Group, LLC.

Heuristics in policymaking: It’s time to figure out what drives policy uncertainty

Policymaking under the pandemic pressure could be subject to cognitive heuristics, allowing the resulting policy uncertainty to influence the market negatively. Researches in economics and finance have long recognized the importance of policy uncertainty. However, most studies take policy uncertainty as a given while focusing on its real or financial influences. The few studies exploring the economic sources of policy uncertainty often attribute it to some sort of external uncertainty faced by the government in making policies. The coronavirus pandemic of 2020 tells a different story. Its influence on the stock market is unpreceded (Baker et al. 2020, Fetzer et al. 2020). Conditioning on the same uncertainty of the pandemic, however, governments across the world formulate and announce different policies. The drastically different real and financial impacts of such policies remind us that policy uncertainty could directly originate from the decision process of policymakers. It is time to figure out what drives policy uncertainty and how to optimize policymaking under crisis. © 2020 by World Scientific Publishing Co. Pte. Ltd.

Analyzing a community worker's stress during the COVID-19 pandemic in China

Purpose Community governance plays an important role in the prevention and control of the Coronavirus disease 2019 (COVID-19) pandemic in China. Community workers, the main executors in community governance, experience a huge amount of stress, which affects their physical and mental health. Thus, it is crucial to pay more attention to the stressors and stress responses of community workers and propose strategies to alleviate such responses. This paper aims to analyze the work stress of community workers during the COVID-19 pandemic in China. Design/methodology/approach Based on a questionnaire survey of 602 community workers during COVID-19 in China, the four main stressors and 14 stress factors of community workers were identified and six factors at three levels of stress responses were defined. A stress analysis model is proposed that tests the mediating role of psychological capital and the moderating role of organizational climate. Findings The results show that stressors influence stress responses through the moderating role of psychological capital, organizational climate plays a negative mediator role between stressors and psychological capital and the main stressors for community workers are work, safety and performance stress. Originality/value This paper contributes to existing research because it offers suggestions for reducing the impact of stress on the community workers during the COVID-19 pandemic. Further, it can promote the control and prevention of the COVID-19.

Impact of Traffic Exposure and Land Use Patterns on the Risk of COVID-19 Spread at the Community Level

This study explores how traffic exposure and land use patterns affect the spread of coronavirus disease 2019 (COVID-19) at the community level. Using the data collected from 1 947 confirmed COVID-19 cases and 315 neighborhoods in A City, this study applied geocodes, kernel density estimation, spatial statistics, and network analysis approaches to obtain 14 indicators related to traffic exposure and land use in a 500 m buffer for each confirmed community. Data from the road network, public transit network, points of interest (POI), and the spatial distribution of national gross domestic product and population in a 1 km×1 km grid in 2015 were used. A classical global Poisson regression model and a geographically weighted Poisson regression model with variable coefficients were adapted to estimate the complex relationships between traffic exposure variables (road network density, facility proximity), land use variables (mixture, intensity), and the spread of COVID-19 at the community level. The results show that the geographically weighted Poisson regression model obtains a better result when the spatial heterogeneity of traffic exposure variables and land use variables is considered. Despite this, road density, public transit density, building density, population density, central business district (CBD) proximity, and land value have a positive impact on the spread of COVID-19 at the community level. However, entrance (exit) proximity, green park proximity, and land use mixture have both positive and negative effects on the spread of COVID-19, and the spatial effects vary significantly. The effects of population density, land value, green park proximity, and land use mixture on the spread of COVID-19 are much higher than those of other variables. This study illustrates that urban space elements have an impact on both communicable and noncommunicable diseases. These findings provide insight for controlling the outbreak of an epidemic in the context of transportation planning and land use. © 2020, Editorial Department of China Journal of Highway and Transport. All right reserved.

Analysis of Urban Greenway Planning Strategies by the Orientation of Healthy City

In the first half-year of 2020, the COVID-19 (Coronavirus disease 2019) outbreak spread rapidly around the world. Under the impact of the crisis of Public Health Emergency, the development of healthy cities and people's lives must be experienced a tough test, and it will trigger the thinking and practice of urban construction as well. Taking the construction of Nanning greenway system as an example, and trying to discuss the route and the significance of healthy cities construction by greenway supporting, we came up with suggestions for greenway construction by the orientation of the concept healthy city. © The Authors, published by EDP Sciences, 2020.

Evaluation of the consistency and detection capability of seven domestic 2019-nCoV nucleic acid detection kits

Objective: To compare the consistency and detection capability of seven 2019-nCoV nucleic acid detection kits, and provide reference for detection method selection of clinical laboratory and diagnosis of new coronavirus pneumonia. Methods: Two batches of pharyngeal swab samples were collected from tenpatients with confirmed infection of 2019-nCoV and 10 suspected patients with negative 2019-nCoV test results during January 29 to February 5, 2020 in Shenzhen Luohu People's Hospital. Seven kinds of kits were labeled as ato g and used for nucleic acid detection respectively to evaluate the consistency of the test results of the clinical samples. A 2019-nCoV positive specimen was selected and diluted to 5-concentration gradient plates (Level-1 to 5) with RNase-free water. The positive detection rate and intra-batch repeatability of different brands of kits were compared. Results: The negative and positive coincidence rates of twenty clinical samples tested by six kinds of kits were 100%, and the positive and negative coincidence rate was 8/10 and 10/10 for the other kit, respectively. The results of intra-batch repeatability showed the CVs of viral loads tested by these seven kits were all less than 5%. In the concentration range of Level-1 to 3, the detection capability for open reading frame (ORF)1ab gene of Kit b,d and f was lower than Kit a,c,e and g, and the detection capability of kit e and g was the highest (14/15). The detection capability for N gene of Kit a (15/15) was higher than the other 5 kits. The comprehensive analysis of the detection capability for ORF1ab and N gene showedthat Kit d had the lowest detection capability (ORF1ab:40%,N:53%), and there was no significant difference in the detection capability of Kit a, b, c, e, and f. Conclusions: There was no significant difference in the accuracy and repeatability of the seven kits for positive samples with high viral loads, and the detection performance was good;but some kits had poor detection capability for weak positive samples. It is suggested that the weak positive samples should be rechecked by at least two manufacturers' kits to ensure the accuracy of the results.

Gene Cloning and Sequence Analysis of Angiotensin Converting Enzyme 2 (ACE2) in China Sheldrake Duck

Since the discovery of angiotensin-converting enzyme 2 (ACE2),its pathophysiological functions,especially as functional receptors for coronaviruses such as SARS and COVID-19,have shown great potential.To clarify the gene sequence and structure of different species can provide a basis for the study of the mechanism of coronavirus infection. In this experiment,RT-PCR and Western blot were firstly used to detect the presence of ACE2 in different tissues of China Sheldrake duck.Then the homologous cloning and PCR technology were used to amplify the complete ORF sequence of the China Sheldrake duck ACE2 gene,and then TA cloned into pMD-19T.The vector was sequenced,and the obtained sequence was analyzed by bioinformatics. The expression of ACE2 gene and protein in heart,liver,lung,kidney and other tissues was confirmed.Gene cloning results showed that the full-length CDS sequence of the China Sheldrake duck ACE2 gene was 2 435 bp,encoding 805 amino acid residues,and its nucleotide sequence and amino acid sequence homology with human ACE2 were 66.2% and 66.4%,respectively,and on different branches of the evolutionary tree.Analysis of the 18 key amino acid residues related to the binding of the SARS virus S protein in humans found that except for the 330th and 353th amino acids, the rest were different from humans. Structural analysis revealed that the duck ACE2 was a type I transmembrane protein with multiple N-glycosylation sites.The study obtained the complete ORF sequence and related basic data of the ACE2 gene of China Sheldrake duck for the first time. The obtained sequence had been uploaded to GenBank and successfully included.The results provided a theoretical basis for the functional study of ACE2 on ducks.