The Pandemic as a Catalyst for Digital Pathology Adoption as an LDT

Whole-slide images (WSI) are the basis for the application of artificial intelligence/machine learning and other informatics methods to histological diagnosis and will further blur the line separating anatomic and clinical pathology. FDA classified WSI systems for primary diagnosis as class III (highest risk) medical devices until 2017. This discouraged anatomic pathology laboratories at risk-averse domestic institutions like mine from investing in these digital pathology (DP) platforms. In 2017, FDA downgraded WSI to class II (moderate risk) when they de-novo approved a system marketed by Philips. We were not interested in that system at my institution, but the downgrade caused us to reset our perception of the risk of validating a RUO system for primary diagnosis. Cost remained a barrier. In April 2020, FDA issued temporary guidance stating they would not enforce premarket approval of WSI systems to facilitate pathologists working remotely during the SARS-CoV-2 pandemic. The guidance included a statement that "laboratories and hospitals consider performing a validation study.” In January 2021, FDA proposed making the temporary non-enforcement guidance permanent. So, in a little more than three years, WSI for primary diagnosis had gone from class III to exempted from pre-market approval! This nicely aligned the approval framework for WSI with the approval framework for our conventional optical microscopes, which are statutorily exempted from approval, and further reset our perception of risk. In April 2021, FDA withdrew the proposal to make non-enforcement permanent, but the temporary non-enforcement guidance is still in effect at the time of writing. Amid all this FDA activity, the College of American Pathologists updated and reissued their consensus guidelines for validating WSI systems for diagnostic purposes in March 2021. The narrative mentions the FDA's recent approval of a few WSI systems and anticipates more, but the expert panel recommendations do not include any related to the approval status of systems. The reissue of this document reminded us that, as clinical laboratorians, we are capable of safely validating WSI as a laboratory-developed test and are supported in doing so by consensus guidelines from one of our leading professional organizations. In early 2021 we committed to funding a DP initiative to make WSI part of our routine histological process for 10% of our anatomic pathology cases. The initial capital investment is $1.5M. When realized, the microscope slides for designated pathology services will be transported directly from the cover slipper to a slide scanner and electronically distributed to pathologists using a clinical-grade image management system that we share with our radiology department. We made the decision to fund this in the context of the regulatory (decreased perception of risk), sociological (demand for remote telepathology), and technological (availability of scalable WSI systems) changes that occurred during the pandemic.

CATALYTIC PYROLYSIS OF DISCARDED COVID-19 MASKS OVER SEPIOLITE

This research aims to develop a new strategy to valorize wasted COVID-19 masks based on pyrolysis to convert them into useful products. First, surgical and FFP2 masks were thermally pyrolyzed at temperatures of 450–550 ºC with the purpose of determining gas, liquid (oil) and solid (char) yields. At low temperatures, solid yield was high, while at high temperatures the gas product was enhanced. The highest yield of liquid was found at an operating temperature of 500 ºC in both surgical and FPP2 masks pyrolysis. The liquid product yields were 59.08% and 58.86%, respectively. Then, the volatiles generated during thermal pyrolysis of residual masks were cracked over sepiolite as catalyst at a temperature of 500 ºC. The catalytic pyrolysis increased the yield of gas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks) and decreased the viscosity of the liquid product. Finally, the effect of sepiolite regeneration and reuse in consecutive pyrolysis tests was examined. Results showed that, with the higher regeneration-reuse of sepiolite, the catalyst was degraded obtaining a liquid product with higher molecular mass. This effect was hardly noticeable in the case of FFP2 masks. © 2022 International Multidisciplinary Scientific Geoconference. All rights reserved.

GIS-Based Analysis of the Spatial Distribution and Influencing Factors of Traditional Villages in Hebei Province, China

Traditional villages are a valuable cultural asset that occupy an important position in Chinese traditional culture. This study focuses on 206 traditional villages in Hebei Province and aims to explore their spatial distribution characteristics and influencing factors using ArcGIS spatial analysis. The analysis shows that traditional villages in Hebei Province were distributed in clusters during different historical periods, and eventually formed three core clusters in Shijiazhuang, Zhangjiakou and Xingtai-Handan after different historical periods. Moreover, the overall distribution of traditional villages in Hebei Province is very uneven, with clear regional differences, and most of them are concentrated in the eastern foothills of the Taihang Mountains. To identify the factors influencing traditional villages, natural environmental factors, socio-economic factors, and historical and cultural factors are considered. The study finds that socio-economic and natural environmental factors alternate in the spatial distribution of traditional villages in Hebei Province. The influence of the interaction of these factors increases significantly, and socio-economic factors have a stronger influence on the spatial distribution. Specifically, the spatial distribution of traditional villages in Hebei Province is influenced by natural environmental factors, while socio-economic factors act as drivers of spatial distribution. Historical and cultural factors act as catalysts of spatial distribution, and policy directions are external forces of spatial distribution. Overall, this study provides valuable insights into the spatial distribution characteristics and influencing factors of traditional villages in Hebei Province, which can be used to develop effective strategies for rural revitalisation in China.

Recovery of Platinum and Palladium from Spent Automotive Catalysts: Study of a New Leaching System Using a Complete Factorial Design

The recovery of materials and energy from end-of-life products is increasingly a fundamental factor in the sustainable development of various countries. Recovering metals from different types of waste is not only a practice in support of the environment, but is also a profitable economic activity. For this reason, exhausted automotive catalysts can become renewable sources of critical raw materials such as Pt, Pd, and Rh. However, recovering Pt and Pd from spent catalysts through an efficient, economical, and green method remains a challenge. This article presents a new leaching process for the hydrometallurgical recovery of Pt and Pd from exhausted automotive catalysts. The leaching solution consists of an aqueous mixture of hydrochloric acid, two organic acids (citric acid and acetic acid) and hydrogen peroxide. A complete factorial plan on two levels (2k) was performed in order to evaluate the main effects of the analyzed factors and their interactions. The factors that were presumed to be the most influential on the leaching of Pt and Pd were the concentrations of the different reagents and the reaction time. The optimal circumstances for achieving the largest recovery (over 80% Pt and 100% Pd) were achieved using the following conditions: a concentration of HCl of 5 M, a concentration of H2O2 of 10% wt./vol., a concentration of C2H4O2 of 10%vol./vol., and a reaction time of 3 h.

Coal Is a Priority for Energy Security, until It Is Not: Coal Phase-Out in the EU and Its Persistence in the Face of the Energy Crisis

In the wake of the COVID-19 pandemic and the Russian invasion of Ukraine, many countries see coal as the easiest solution to their energy sector challenges, despite the consequences for climate goals. Several countries of the European Union started to re-evaluate their coal policies vis-à-vis the current energy crisis and, although such a change is expected to be short-term in nature, it nevertheless has negative consequences for the Union's 2050 climate goal. However, most of the EU countries did not revise their phase-out goals. This paper examines Slovakia as a country that embarked on a coal phase-out trajectory only a few years before the pandemic broke out and stayed firmly on this path despite benefits stemming from the continued use of domestic coal. Domestic coal used to be considered a safeguard of energy security in Slovakia, especially after the 2009 gas crisis. However, a decision was made in 2018 to phase out coal by 2023, and this has not changed despite increased focus on domestic energy sources as energy security guarantors during the current energy crisis. This paper explains the decision in favour of a coal phase-out and its support vis-à-vis the energy crisis using the concept of ‘financial Europeanisation', which stresses the importance of EU funds for the development of the domestic policies of EU member states. While the expected funds serve as a catalyst for the coal phase-out needed to reach climate goals, short-term advantages of revising a coal phase-out were outweighed by long-term benefits provided by EU funds.

Challenges Facing Artificial Intelligence Adoption during COVID-19 Pandemic: An Investigation into the Agriculture and Agri-Food Supply Chain in India

The coronavirus (COVID-19) pandemic has witnessed a significant loss for farming in India due to restrictions on movement, limited social interactions and labor shortage. In this scenario, Artificial Intelligence (AI) could act as a catalyst for helping the farmers to continue with their farming. This study undertakes an analysis of the applications and benefits of AI in agri-food supply chain, while highlights the challenges facing the adoption of AI. Data were obtained from 543 farmers in Odisha (India) through a survey, and then interpreted using "Interpretive Structural Modelling (ISM)”;MICMAC;and "Step-Wise-Assessment and Ratio-Analysis (SWARA)”. Response time and accuracy level;lack of standardization;availability of support for big data;big data support;implementation costs;flexibility;lack of contextual awareness;job-losses;affordability issues;shortage of infrastructure;unwillingness of farmers;and AI safety-related issues are some challenges facing the AI adoption in agri-food supply chain. Implications were drawn for farmers and policy makers.

Sustainable production of dimethyl-protected cyclic lysine over Pd/m-Al2O3-Si catalysts and its application in synthesis of antibacterial nylon‑6 copolymers

• Pd/ m- Al 2 O 3 -Si catalyst exhibited high efficiency in converting α- amino -ε- caprolactam (α- ACL) to dimethyl-protected cyclic lysine (DMCL). • The lack of Brönsted acid sites on Pd/ m- Al 2 O 3 -Si surface facilitated the formation of DMCL and suppressed undesirable reaction process. • Pd/ m- Al 2 O 3 -Si catalyst with microspherical morphology performed excellent stability and physical strength during the catalytic process. • The nylon‑6 copolymers produced from the as-synthesized DMCL exhibited a great potential in the synthesis of self-cleaning antibacterial materials. Antibacterial monomers are prerequisites for synthesizing antibacterial polymers, especially during the current COVID-19 pandemic. Dimethyl-protected cyclic lysine (DMCL) is a promising functional monomer for nylon-6 based self-cleaning antibacterial polymers. However, the production of DMCL still faces formidable challenges, such as harsh reaction conditions and low catalyst activities. In this study, we developed a Pd/ m -Al 2 O 3 -Si catalyst, which exhibited high efficiency in converting α -amino- ε -caprolactam (α -ACL) to DMCL, affording a yield of as high as 97.1% at 100 °C and 1 MPa H 2. The lack of Brönsted acid sites on the catalyst surface facilitated the formation of DMCL and suppressed undesirable hydrolysis or cracking by-products from the lactam-based reactant. The recycled experiments showed that Pd/ m -Al 2 O 3 -Si performed excellent stability and physical strength with essentially no damage to its microspheres after the reaction. The nylon‑6 copolymers produced from the as-synthesized DMCL exhibited similar structure and thermal stability with pure nylon-6, showing great potential in synthesizing the self-cleaning antibacterial polymers. This work provides a sustainable and efficient method for producing DMCL and other lysine-based antibacterial monomers, showing a great prospect for the utilization of bio-based chemicals in synthesizing functional polymers. [ FROM AUTHOR] Copyright of Chemical Engineering Journal is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Synthesis, DFT and In Silico Anti-COVID Evaluation of Novel Tetrazole Analogues

A new series of 3-aryl/heteroaryl-2-(1H-tetrazol-5-yl) acrylamides have been synthesized through catalyst-free, one-pot cascade reactions, utilizing click chemistry approach and evaluated for their anti-COVID activities against two proteins in silico. The structural properties of the synthesized molecules were evaluated based on DFT calculations. Total energy of the synthesized tetrazole compounds were obtained through computational analysis which indicate the high stability of the synthesized compounds. The Frontier Molecular Orbitals (FMO) and associated energies and molecular electrostatic potential (MEP) surfaces were generated for the compounds. Spectral analysis by DFT gave additional evidence to the structural properties of the synthesized molecules. All tetrazole analogues come under good ADMET data as they followed the standard value for ADMET parameters. Docking studies offered evidence of the molecules displaying excellent biological properties as an anti-Covid drug. Compound 4 g exhibited excellent anti-COVID-19 properties with four hydrogen binding interactions with amino acids GLN 2.486 Å, GLN 2.436 Å, THR 2.186 Å and HSD 2.468 Å with good full-fitness score (–1189.12) and DeltaG (–7.19). Similarly, compound 4d shown potent activity against anti-COVID-19 mutant protein (PDB: 3K7H) with three hydrogen binding interactions, i.e., SER 2.274 Å, GLU 1.758 Å and GLU 1.853 Å with full-fitness score of –786.60) and DeltaG (–6.85). The result of these studies revealed that the compounds have the potential to become lead molecules in the drug discovery process.

Sustainable tourism and the Sustainable Development Goals in sub-national island jurisdictions: The case of Tobago

Tourism has the potential to contribute to achieving the Sustainable Development Goals (SDGs) agreed to by United Nations member states. For sustainable tourism to be successful, stakeholders must be involved in the process. The aim of this study is to consider the extent to which sustainable tourism contributes to achieving the SDGs and how tourism stakeholders understand and implement sustainable tourism. Specifically, the study adopted a qualitative approach and used the case study of Tobago. The data were collected using focus groups of tourism stakeholders. The research revealed that stakeholders embraced the SDGs despite a lack of understanding. They were unable to provide a comprehensive definition of sustainable tourism and their relation to the SDGs, but recognised its traditional components along with specific island features. Stakeholders more easily listed sustainable tourism practices and potential and their link to the SDGs. The barriers to sustainable tourism centred mainly on the role of the local governing body and political affiliation, dependency on the mainland, and prohibitive costs. Action is needed to facilitate broader stakeholder awareness and collaboration in support of efforts to enhance sustainable tourism and the achievement of the SDGs, where policymakers need to act as a catalyst for change.

Pathology Education Powered by Virtual and Digital Transformation: Now and the Future

[...]standing on the crest of yet another wave of change, driven by artificial intelligence (AI) and machine learning,2 pathology educators may soon be challenged to convey the best ways to apply these tools to the problems of diagnostic pathology for the coming generation of learners and the present corps of practitioners.3 Hence, this collaborative effort aims to describe the genetic code governing the transmission of pathology knowledge to subsequent generations of medical professionals.4 We aim to expose not just the code but also the supporting array of catalysts, enhancers, and other cofactors now in place to ensure we have a robust and potent supply of pathologists. APPLYING DP IN UNDERGRADUATE MEDICAL, DENTAL, VETERINARY, AND ALLIED HEALTH EDUCATION Beginning in 1985, this technology has been progressively more widely implemented in undergraduate medical, dental, veterinary, and allied health (nursing, pharmacy, medical technology, etc) education platforms in the United States and internationally.5,11-26 As noted above, virtual microscopy laboratories, available on personal devices or in school-based computer labs, have replaced fixed laboratories housing gross specimens, boxes of glass slides, and student microscopes. WSI with links to supplementary resources, such as gross and radiologic images and additional study material, provide enrichment for the teaching and learning experience in the new virtual environment. [...]significant exposure to microanatomy and the laboratory methods of pathology underpinning so much of diagnosis, therapy, and management is foundational.

Mechanism of microwave-assisted iron-based catalyst pyrolysis of discarded COVID-19 masks

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

Mental Health and Information Technology Catalysts as Determinants of Innovative Work Behavior

Interpersonal interactions, such as impromptu face-to-face workplace conversations, facilitate knowledge transfer and spur innovation within individual work roles;however, the move to remote work during the COVID-19 pandemic disrupted these dynamics. This research examines how innovation can be maintained in remote work settings by considering Information Technology (IT) catalysts (a combination of IT mindfulness, IT identity, and IT empowerment) during disruptive events and crises. We also highlight the importance of remote workers' mental health and coping as precursors for IT catalysts to stimulate innovative work behaviors. Our paper contributes to information systems (IS) theory by establishing remote workers' mental health and coping as distal factors of innovation and precursors to IT catalysts. In addition, we extend IS theory by establishing the relationships among the IT catalyst factors as well as their impact on innovative work behaviors. Our research provides insights for organizations interested in sustaining innovation, especially during crises or other stress-inducing events or conditions. © 2023 by the Association for Information Systems.

BORON-HYDROGEN MATERIALS TOWARDS DECARBONISATION

Boron-hydrogen (B-H) materials are used as hydrogen and heat sources, due to their reducing potential. It has been shown again with the COVID-19 pandemic that greenhouse gas activities are anthropogenic in origin. In particular, the conversion of carbon dioxide (CO2) into valuable chemicals has an important place in the fight against the climate crisis. The conversion of anthropogenic CO2 into valuable chemicals has important implications for a habitable world. In many studies in the literature, boron hydrides have been used to produce, hydrogen and convert carbon dioxide into valuable chemicals. Formic acid and methanol obtained by hydrogenation can be seen as the clean energy movement of the future with its value in hydrogen storage. The type of valuable chemicals that will be formed by the hydrogenation of CO2 is directly related to the method to be followed. The type of catalyst used, or how much hydrogen molecule interacts with CO2, determines the valuable chemical that will form. Disturbances in the thermodynamics of the hydrogenation of CO2 have been tried to be eliminated by various types of catalysts and necessary condition optimizations. Many catalysts and methods developed for the hydrogenation of CO2 were examined. This study discusses the use of B-H materials via catalytic conversion of CO2 into valuable chemicals in terms of critical factors such as reaction conditions, selection of catalyst, and solvent. © 2022 Proceedings of WHEC 2022 - 23rd World Hydrogen Energy Conference: Bridging Continents by H2. All rights reserved.

Coronavirus-like Core-Shell-Structured Co@C for Hydrogen Evolution via Hydrolysis of Sodium Borohydride.

Constructing a reliable and robust cobalt-based catalyst for hydrogen evolution via hydrolysis of sodium borohydride is appealing but challenging due to the deactivation caused by the metal leaching and re-oxidization of metallic cobalt. A unique core-shell-structured coronavirus-like Co@C microsphere was prepared via pyrolysis of Co-MOF. This special Co@C had a microporous carbon coating to retain the reduced state of cobalt and resist the metal leaching. Furthermore, several nano-bumps grown discretely on the surface afforded enriched active centers. Applied in the pyrolysis of NaBH4, the Co@C-650, carbonized at 650 °C, exhibited the best activity and reliable recyclability. This comparable performance is ascribed to the increased metallic active sites and robust stability.

Mental Health and Information Technology Catalysts as Determinants of Innovative Work Behavior

Interpersonal interactions, such as impromptu face-to-face workplace conversations, facilitate knowledge transfer and spur innovation within individual work roles;however, the move to remote work during the COVID-19 pandemic disrupted these dynamics. This research examines how innovation can be maintained in remote work settings by considering Information Technology (IT) catalysts (a combination of IT mindfulness, IT identity, and IT empowerment) during disruptive events and crises. We also highlight the importance of remote workers' mental health and coping as precursors for IT catalysts to stimulate innovative work behaviors. Our paper contributes to information systems (IS) theory by establishing remote workers' mental health and coping as distal factors of innovation and precursors to IT catalysts. In addition, we extend IS theory by establishing the relationships among the IT catalyst factors as well as their impact on innovative work behaviors. Our research provides insights for organizations interested in sustaining innovation, especially during crises or other stress-inducing events or conditions.

Mental Health and Information Technology Catalysts as Determinants of Innovative Work Behavior

Interpersonal interactions, such as impromptu face-to-face workplace conversations, facilitate knowledge transfer and spur innovation within individual work roles;however, the move to remote work during the COVID-19 pandemic disrupted these dynamics. This research examines how innovation can be maintained in remote work settings by considering Information Technology (IT) catalysts (a combination of IT mindfulness, IT identity, and IT empowerment) during disruptive events and crises. We also highlight the importance of remote workers' mental health and coping as precursors for IT catalysts to stimulate innovative work behaviors. Our paper contributes to information systems (IS) theory by establishing remote workers' mental health and coping as distal factors of innovation and precursors to IT catalysts. In addition, we extend IS theory by establishing the relationships among the IT catalyst factors as well as their impact on innovative work behaviors. Our research provides insights for organizations interested in sustaining innovation, especially during crises or other stress-inducing events or conditions.

Multi-Criteria Analysis of Sustainable Travel and Tourism Competitiveness in Europe and Eurasia

The travel and tourism industry has numerous components that contribute to the economy and create new jobs since it is a service sector that incorporates other service networks. Furthermore, it acts as a catalyst in sustaining investment attractiveness and economic indicators such as closing the current account deficit. The Travel and Tourism Competition Index utilized in this research has four dimensions and fourteen indicators. In this research, the Entropy-based VIKOR approach, which is a Multi-Criteria Decision-Making method, Spearman Correlation analysis, and K-means clustering analysis were employed to propose a methodological novelty in this field. The study analyzed the competitiveness of significant European and Eurasian nations based on key indicators. According to country evaluations, Spain, France, Germany, the United Kingdom, Italy, and Switzerland differ from other countries in a positive sense and with a significant difference. Eastern European and Balkan nations are often at the bottom of the table. As a consequence of this study, it is expected that the results of future studies using other methodologies or methods will be compared with this study. At the same time, it is aimed to explain the relevant indicators and their dimensions.

The COVID-19 pandemic and insecurity: the furiousness in Nigerian communities

The COVID-19 pandemic has generally induced mass panic and threat across the world, including Nigeria, due to the perceived uncertainties, fears and insecurities in the communities. Based on this backdrop, this study examined COVID-19 pandemic and insecurity in Nigeria. Convenience accidental sampling was used to administer 1671 copies of a questionnaire on residents through an online/electronic survey. Data collected were analysed descriptively and inferentially. Findings revealed that the spike in crime during the COVID-19 lockdown period is relatively higher than usual with disruption of public peace, theft and rape accounting for the most prominent crime. Meanwhile, most respondents experienced crime incidence between 6 pm and 12 midnight. Ironically, idleness, poor spatial arrangement/planning, poor governance and poverty were the major catalysts for the crime spike during the lockdown, while fear-of-fear (phobophobia) and declined socio-economic capacity were predominant effects of crime experienced. The Fisher’s exact test results revealed a significant relationship between the surge in crime and COVID-19-restrictive measures. The study concludes that the insecurities during lockdown periods have caused both temporary and permanent physical and psychological havoc;hence, it recommends quick advancement of the built environment with smart security measures and social supports for the citizenry during the pandemic.

Polyimide Surface Dielectric Barrier Discharge for Inactivation of SARS-CoV-2 Trapped in a Polypropylene Melt-Blown Filter

Surface dielectric barrier discharge (SDBD) was used to inactivate the infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) trapped in a polypropylene (PP) melt-blown filter. We used a dielectric barrier made of polyimide films with hexagonal holes through which air flowed. In a cylindrical wind tunnel, the SDBD device supplied reactive oxygen species such as ozone to the SARS-CoV-2 trapped in the PP filter. A plaque assay showed that SDBD at an ozone concentration of approximately 51.6 ppm and exposure time of 30 min induced more than 99.78% reduction for filter-adhered SARS-CoV-2. A carbon catalyst after SDBD effectively reduced ozone exhaust below 0.05 ppm. The combination of SDBD, PP filter, and catalyst could be a promising way to decrease the risk of secondary infection due to indoor air purifiers.

Ultrasensitive NO Sensor Based on a Nickel Single-Atom Electrocatalyst for Preliminary Screening of COVID-19.

A new coronavirus, SARS-CoV-2, has caused the coronavirus disease-2019 (COVID-19) epidemic. A rapid and economical method for preliminary screening of COVID-19 may help to control the COVID-19 pandemic. Here, we report a nickel single-atom electrocatalyst that can be printed on a paper-printing sensor for preliminary screening of COVID-19 suspects by efficient detection of fractional exhaled nitric oxide (FeNO). The FeNO value is confirmed to be related to COVID-19 in our exploratory clinical study, and a machine learning model that can accurately classify healthy subjects and COVID-19 patients is established based on FeNO and other features. The nickel single-atom electrocatalyst consists of a single nickel atom with N2O2 coordination embedded in porous acetylene black (named Ni-N2O2/AB). A paper-printed sensor was fabricated with the material and showed ultrasensitive response to NO in the range of 0.3-180 ppb. This ultrasensitive sensor could be applied to preliminary screening of COVID-19 in everyday life.