ABSTRACT
Dental services are yet to return to a semblance of normality owing to the fear and uncertainty associated with the possible airborne transmission of diseases. The present study aims to investigate the impacts of environmental conditions [changes in ventilation location, ventilation rate, and relative humidity (RH)] and variations in dental patient's breathing rate on droplet transmission during dental service. Computational fluid dynamics simulation was performed based on our previous experimental study during ultrasonic scaling. The impacts of different factors were numerically analyzed by the final fate and proportion of emitted droplets in the dental surgery environment. The results revealed that about 85% of droplets deposited near the dental treatment region, where the patient's torso, face, and floor (dental chair) accounted for around 63%, 11%, and 8.5%, respectively. The change in the ventilation location had a small impact on the deposition of larger droplets (> 60 mu m), and a spatial region with high droplet mass concentration would be presented near the dental professional. The change in the ventilation rate from 5 to 8 ACH led to a 1.5% increment in the fraction of escaped droplets. 50% RH in dental environments was recommended to prevent droplets' fast evaporation and potential mold. Variations in the patient's breathing rate had little effect on the final fate and proportion of emitted droplets. Overall, environmental factors are suggested to maintain 50% RH and larger ACH in dental surgery environments. The findings can give policymakers insights into the role of environmental factors on infection control.
ABSTRACT
Countries around the world have sought efficient protective coverings, including masks, gowns, and fabrics, for air purification to protect people against infectious diseases. However, the demand for significant quantities of disposable protective textiles poses a global challenge, especially when the production of protective gear is suspended due to COVID-19 outbreaks in factories and along supply lines. Therefore, the development of reusable, self-decontaminating protective masks and coverings loaded with disinfectants, such as antibacterial peroxide species, presents an attractive strategy to fight against bacteria risks. In this work, we incorporated persulfate ions, which serve as stable active peroxide precursors, into two porous zirconium-based metal-organic frameworks (Zr-MOFs), enabling these materials to act as regenerable reservoirs for the slow release of biocidal hydrogen peroxide upon hydrolysis by contact with humid air. Single-crystal X-ray diffraction studies reveal the two different coordination motifs for the persulfate ions, which can either bridge between two adjacent nodes or coordinate to a single node depending on both the node connectivity and the distances between open metal sites. The active peroxide precursors within the porous Zr-MOF carriers are stable during storage and easily regenerated once consumed. Importantly, these persulfate-loaded Zr-MOFs can be integrated onto textiles using a facile aqueous in-situ growth procedure, and these composites demonstrate potent and reusable biocidal activity against both Gram-negative bacteria and Gram-positive bacteria. Overall, this approach presents a viable strategy to develop robust protective textiles capable of rapidly deactivating pathogens.
ABSTRACT
The SARS-CoV-2 pandemic outbreak and the unfortunate misuse of toxic chemical warfare agents (CWAs) highlight the importance of developing functional materials to protect against these chemical and pathogen threats. Metal-organic frameworks (MOFs), which comprise a tunable class of crystalline porous materials built from inorganic nodes and organic linkers, have emerged as a class of heterogeneous catalysts capable of rapid detoxification of multiple classes of these harmful chemical or biological hazards. In particular, zirconium-based MOFs (Zr-MOFs) feature Lewis acidic nodes that serve as active sites for a wide range of catalytic reactions, including the hydrolysis of organophosphorus nerve agents within seconds in basic aqueous solutions. In addition, postsynthetic modification of Zr-MOFs enables the release of active species capable of reacting with and deactivating harmful pathogens. Despite this impressive performance, utilizing Zr-MOFs in powder form is not practical for application in masks or protective uniforms. To address this challenge, our team sought to develop MOF/fiber composite systems that could be adapted for use under realistic operating conditions to protect civilians, military personnel, and first responders from harmful pathogens and chemical warfare agents. Over the last several years, our group has designed and fabricated reactive and biocidal MOF/fiber composites that effectively capture and deactivate these toxic species. In this Account, we describe the evolution of these porous and reactive MOF/fiber composites and focus on key design challenges and considerations. First, we devised a scalable method for the integration of Zr-MOFs onto textile substrates using aqueous precursor solutions and without using pretreated textiles, highlighting the potential scalability of this method. Moving beyond standard textiles, we also developed a microbial synthesis strategy to prepare hierarchically porous MOF/bacterial cellulose nanofiber composite sponges that can both capture and detoxify nerve agents when exposed to contaminated gas flows. The mass loading of the MOF in the nanofibrous composite sponge is up to 90%, affording higher work capacities compared to those of textile-fiber-based composites with relatively lower MOF loadings. Next, we demonstrated that heterogeneous polymeric bases are suitable replacements for volatile liquid bases typically used in solution-phase reactions, and we showed that these composite systems are capable of effectively hydrolyzing nerve agents in the solid state by using only water that is present as humidity. Moreover, incorporating a reactive dye precursor into the composite affords a dual function sensing and detoxifying material that changes color from white to orange upon reaction with the byproduct following nerve agent hydrolysis, demonstrating the versatility of this platform for use in decontamination applications. We then created chlorine-loaded MOF/fiber composites that act as biocidal and reactive textiles that are capable of not only detoxifying sulfur-mustard-based chemical warfare agents and simulants but also deactivating both bacteria and the SARS-CoV-2 virus within minutes of exposure. Finally, we synthesized a mixed-metal Ti/Zr-MOF coating on cotton fibers to afford a photoactive biocidal cloth that shows fast and broad-spectrum biocidal performance against viruses and Gram-positive and Gram-negative bacteria under visible light irradiation. Given the tunable, multifunctional nature of these MOF/fiber composites, we believe that this Account will offer new insights for the rational design and preparation of functional MOF/fiber composites and pave the way toward the development of next-generation reactive and protective textiles.
ABSTRACT
Teacher self-efficacy is among the most valued teacher motivational constructs. However, little is known about university teachers' self-efficacy and even less about changes to it throughout the Covid-19-related online teaching. This study applied a retrospective pre- and post-design to investigate changes in online teaching self-efficacy (OTSE) during Covid-19. Participants included 160 Chinese university teachers, who reported their OTSE before and after the COVID-19 lockdowns, adaptability and administration quality together with demographic information. The self-efficacy for online instruction failed to increase significantly over this period (β=.21, p =.083), whereas that for online technology applications increased significantly (β=.329, p <.01). Individual adaptability and administration quality significantly moderated the changes in OTSE. The implications and limitations of the study are discussed. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
ABSTRACT
Countries around the world have sought efficient protective coverings, including masks, gowns, and fabrics, for air purification to protect people against infectious diseases. However, the demand for significant quantities of disposable protective textiles poses a global challenge, especially when the production of protective gear is suspended due to COVID-19 outbreaks in factories and along supply lines. Therefore, the development of reusable, self-decontaminating protective masks and coverings loaded with disinfectants, such as antibacterial peroxide species, presents an attractive strategy to fight against bacteria risks. In this work, we incorporated persulfate ions, which serve as stable active peroxide precursors, into two porous zirconium-based metal-organic frameworks (Zr-MOFs), enabling these materials to act as regenerable reservoirs for the slow release of biocidal hydrogen peroxide upon hydrolysis by contact with humid air. Single-crystal X-ray diffraction studies reveal the two different coordination motifs for the persulfate ions, which can either bridge between two adjacent nodes or coordinate to a single node depending on both the node connectivity and the distances between open metal sites. The active peroxide precursors within the porous Zr-MOF carriers are stable during storage and easily regenerated once consumed. Importantly, these persulfate-loaded Zr-MOFs can be integrated onto textiles using a facile aqueous in-situ growth procedure, and these composites demonstrate potent and reusable biocidal activity against both Gram-negative bacteria and Gram-positive bacteria. Overall, this approach presents a viable strategy to develop robust protective textiles capable of rapidly deactivating pathogens. © 2023 American Chemical Society.
ABSTRACT
CT is an important imaging tool for the diagnosis of novel coronavirus pneumonia (COVID-19), therefore, it's necessary to strictly control the disinfection of CT workplace and equipment and biosafety to avoid the place from becoming a potential infection source and to reduce the risk of infection of patients and radiological staff. It is also necessary to reduce the CT scan dose to minimize the radiation hazards on patients under the premise of ensuring the CT image quality and diagnostic efficiency. Based on the survey that novel coronavirus residues after disinfection at some CT workplace in domestic and overseas and the application of low-dose CT scan in diagnosis of COVID-19, as well as the current situation of radiological protection management in emergency hospital, this paper summarizes and proposes suggestions on infection control and radiological protection for CT workplace to strengthen the defense line of COVID-19 prevention and control.Copyright © 2021 by the Chinese Medical Association.
ABSTRACT
Background:Coronavirus disease 2019 (COVID-19) is a serious and even lethal respiratory illness. The mortality of critically ill patients with COVID-19, especially short term mortality, is considerable. It is crucial and urgent to develop risk models that can predict the mortality risks of patients with COVID-19 at an early stage, which is helpful to guide clinicians in making appropriate decisions and optimizing the allocation of hospital resoureces.Methods:In this retrospective observational study, we enrolled 949 adult patients with laboratory-confirmed COVID-19 admitted to Tongji Hospital in Wuhan between January 28 and February 12, 2020. Demographic, clinical and laboratory data were collected and analyzed. A multivariable Cox proportional hazard regression analysis was performed to calculate hazard ratios and 95% confidence interval for assessing the risk factors for 30-day mortality.Results:The 30-day mortality was 11.8% (112 of 949 patients). Forty-nine point nine percent (474) patients had one or more comorbidities, with hypertension being the most common (359 [37.8%] patients), followed by diabetes (169 [17.8%] patients) and coronary heart disease (89 [9.4%] patients). Age above 50 years, respiratory rate above 30 beats per minute, white blood cell count of more than10 × 109/L, neutrophil count of more than 7 × 109/L, lymphocyte count of less than 0.8 × 109/L, platelet count of less than 100 × 109/L, lactate dehydrogenase of more than 400 U/L and high-sensitivity C-reactive protein of more than 50 mg/L were independent risk factors associated with 30-day mortality in patients with COVID-19. A predictive CAPRL score was proposed integrating independent risk factors. The 30-day mortality were 0% (0 of 156), 1.8% (8 of 434), 12.9% (26 of 201), 43.0% (55 of 128), and 76.7% (23 of 30) for patients with 0, 1, 2, 3, ≥4 points, respectively.Conclusions:We designed an easy-to-use clinically predictive tool for assessing 30-day mortality risk of COVID-19. It can accurately stratify hospitalized patients with COVID-19 into relevant risk categories and could provide guidance to make further clinical decisions. © 2021 The Chinese Medical Association, Published by Wolters Kluwer Health, Inc.
ABSTRACT
The SARS-CoV-2 pandemic outbreak and the unfortunate misuse of toxic chemical warfare agents (CWAs) highlight the importance of developing functional materials to protect against these chemical and pathogen threats. Metal-organic frameworks (MOFs), which comprise a tunable class of crystalline porous materials built from inorganic nodes and organic linkers, have emerged as a class of heterogeneous catalysts capable of rapid detoxification of multiple classes of these harmful chemical or biological hazards. In particular, zirconium-based MOFs (Zr-MOFs) feature Lewis acidic nodes that serve as active sites for a wide range of catalytic reactions, including the hydrolysis of organophosphorus nerve agents within seconds in basic aqueous solutions. In addition, postsynthetic modification of Zr-MOFs enables the release of active species capable of reacting with and deactivating harmful pathogens. Despite this impressive performance, utilizing Zr-MOFs in powder form is not practical for application in masks or protective uniforms.To address this challenge, our team sought to develop MOF/fiber composite systems that could be adapted for use under realistic operating conditions to protect civilians, military personnel, and first responders from harmful pathogens and chemical warfare agents. Over the last several years, our group has designed and fabricated reactive and biocidal MOF/fiber composites that effectively capture and deactivate these toxic species. In this Account, we describe the evolution of these porous and reactive MOF/fiber composites and focus on key design challenges and considerations.First, we devised a scalable method for the integration of Zr-MOFs onto textile substrates using aqueous precursor solutions and without using pretreated textiles, highlighting the potential scalability of this method. Moving beyond standard textiles, we also developed a microbial synthesis strategy to prepare hierarchically porous MOF/bacterial cellulose nanofiber composite sponges that can both capture and detoxify nerve agents when exposed to contaminated gas flows. The mass loading of the MOF in the nanofibrous composite sponge is up to 90%, affording higher work capacities compared to those of textile-fiber-based composites with relatively lower MOF loadings. Next, we demonstrated that heterogeneous polymeric bases are suitable replacements for volatile liquid bases typically used in solution-phase reactions, and we showed that these composite systems are capable of effectively hydrolyzing nerve agents in the solid state by using only water that is present as humidity. Moreover, incorporating a reactive dye precursor into the composite affords a dual function sensing and detoxifying material that changes color from white to orange upon reaction with the byproduct following nerve agent hydrolysis, demonstrating the versatility of this platform for use in decontamination applications. We then created chlorine-loaded MOF/fiber composites that act as biocidal and reactive textiles that are capable of not only detoxifying sulfur-mustard-based chemical warfare agents and simulants but also deactivating both bacteria and the SARS-CoV-2 virus within minutes of exposure. Finally, we synthesized a mixed-metal Ti/Zr-MOF coating on cotton fibers to afford a photoactive biocidal cloth that shows fast and broad-spectrum biocidal performance against viruses and Gram-positive and Gram-negative bacteria under visible light irradiation.Given the tunable, multifunctional nature of these MOF/fiber composites, we believe that this Account will offer new insights for the rational design and preparation of functional MOF/fiber composites and pave the way toward the development of next-generation reactive and protective textiles. © 2023 Accounts of Materials Research. Co-published by ShanghaiTech University and American Chemical Society. All rights reserved.
ABSTRACT
Background. The premise of a “good death” is vital in delivering proper care of terminally-ill patients but the COVID-19 pandemic has brought about new challenges and necessary protocols. There is a need to explore this gap in knowledge and understand perspectives of various stakeholders in COVID-19-related deaths. Objectives. To describe the perception, barriers, and facilitators of a “good death” from COVID-19 survivors, relatives, and healthcare providers in the setting of a COVID-19 tertiary hospital. Methods. The study was done in a COVID-19 tertiary hospital in Metro Manila from September to December 2021. Three groups of target respondents were invited to participate in the study: 8 survivors of severe/critical COVID-19, 9 close relatives of COVID-19 patients who had died, and 9 healthcare providers who directly cared for COVID-19 patients who had died. Semi-structured in-depth interviews were conducted by video calls which explored themes on good death. Thematic analysis was also done. Results. A total of 26 respondents were included in the study: 8 COVID-19 survivors, 9 relatives, and 9 healthcare providers. The definition of “Good Death” among the participants focused on "being at peace" and having "everything in order". The experience with COVID-19 were influenced by the fear of the infection and isolation restrictions during hospitalization. Recurring themes across all groups were the fear of COVID-19 and death, importance of family in the healthcare process, difficulty in communication, and cremation viewed as necessary but not preferred. Conclusion. A "good death" is perceived as a peaceful, prepared experience. The main barriers of a "good death' were the strict restrictions on physically comforting and communicating with patients. Video/voice calls and compassionate health care providers facilitated a better hospitalization experience. Careful study and focus on these factors can improve interventions for terminally ill patients to achieve a “good death” in the Filipino socio-cultural context. © 2022 University of the Philippines Manila. All rights reserved.
ABSTRACT
During the period of COVID-19, it is still inevitable for people to contact with each other based on the consideration of economic development. Therefore, the health management measures for staying in the hotel have become an important part of epidemic prevention. As we all know, ultraviolet (UV) light is an effective disinfection and sterilization method, which has been widely used in many applications. In this paper, a hotel anti-epidemic management system is proposed to disinfect the used rooms by using UV LEDs through WiFi communication with the front desk computer, and therefore it can protect quests from virus infection. © 2022 IEEE.
ABSTRACT
In the version of this article initially published, the first name of Chuansheng Zheng was misspelled as Chuangsheng. The error has been corrected in the HTML and PDF versions of the article. © The Author(s) 2022.
ABSTRACT
Artificial intelligence provides a promising solution for streamlining COVID-19 diagnoses;however, concerns surrounding security and trustworthiness impede the collection of large-scale representative medical data, posing a considerable challenge for training a well-generalized model in clinical practices. To address this, we launch the Unified CT-COVID AI Diagnostic Initiative (UCADI), where the artificial intelligence (AI) model can be distributedly trained and independently executed at each host institution under a federated learning framework without data sharing. Here we show that our federated learning framework model considerably outperformed all of the local models (with a test sensitivity/specificity of 0.973/0.951 in China and 0.730/0.942 in the United Kingdom), achieving comparable performance with a panel of professional radiologists. We further evaluated the model on the hold-out (collected from another two hospitals without the federated learning framework) and heterogeneous (acquired with contrast materials) data, provided visual explanations for decisions made by the model, and analysed the trade-offs between the model performance and the communication costs in the federated training process. Our study is based on 9,573 chest computed tomography scans from 3,336 patients collected from 23 hospitals located in China and the United Kingdom. Collectively, our work advanced the prospects of utilizing federated learning for privacy-preserving AI in digital health. The COVID-19 pandemic sparked the need for international collaboration in using clinical data for rapid development of diagnosis and treatment methods. But the sensitive nature of medical data requires special care and ideally potentially sensitive data would not leave the organization which collected it. Xiang Bai and colleagues present a privacy-preserving AI framework for CT-based COVID-19 diagnosis and demonstrate it on data from 23 hospitals in China and the United Kingdom.
ABSTRACT
Background: In this meta-analysis we evaluated strategies on augmentation of host immunity against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. Method: We searched clinical trials registered at the National Institutes of Health by 30 November 2020, and conducted analyses on inoculated population, involved immunological processes, source of injected components, and trial phases. We then searched PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials for their corresponding reports. A bivariate random-effects meta-analysis was used to derive the pooled estimate of seroconversion and adverse events (AEs). Results: A total of 540,269 participants were enrolled in 225 identified trials. The working mechanisms included heterologous immunity, active immunity, passive immunity, and immunotherapy. A total of 2,565 healthy adults from 10 clinical trials were included for meta-analyses. The odd ratio (OR) was 90.82 for kinetics of serologic responses to anti-SARS-CoV-2 antibody IgG titer (95% CI =36.1-228.49;p < 0.00001). The pooled ORs were 2.57 for solicited systemic AEs (95%CI =1.57-4.21;p = 0.0002), 5.72 for solicited local AEs (95% CI=2.59-12.67;p < 0.0001), and 2.08 for unsolicited systemic events (95% CI=1.42-3.05;p = 0.0002), compared to placebo or conservative treatment. Conclusion: Among all immune-augmentative interventions, a paradigm shift to vaccines providing active immunity was observed. The efficacy of these interventions was promising although systemic adverse events were noted.
Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections , Lung/diagnostic imaging , Pandemics , Patient Care Management/methods , Pneumonia, Viral , Radiography, Thoracic/methods , Tomography, X-Ray Computed/methods , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques/methods , Coronavirus Infections/blood , Coronavirus Infections/diagnosis , Coronavirus Infections/physiopathology , Coronavirus Infections/therapy , Humans , Male , Middle Aged , Pneumonia, Viral/blood , Pneumonia, Viral/diagnosis , Pneumonia, Viral/physiopathology , Pneumonia, Viral/therapy , SARS-CoV-2 , Symptom Assessment/methods , Treatment OutcomeABSTRACT
CT is an important imaging tool for the diagnosis of novel coronavirus pneumonia (COVID-19), therefore, it's necessary to strictly control the disinfection of CT workplace and equipment and biosafety to avoid the place from becoming a potential infection source and to reduce the risk of infection of patients and radiological staff. It is also necessary to reduce the CT scan dose to minimize the radiation hazards on patients under the premise of ensuring the CT image quality and diagnostic efficiency. Based on the survey that novel coronavirus residues after disinfection at some CT workplace in domestic and overseas and the application of low-dose CT scan in diagnosis of COVID-19, as well as the current situation of radiological protection management in emergency hospital, this paper summarizes and proposes suggestions on infection control and radiological protection for CT workplace to strengthen the defense line of COVID-19 prevention and control. Copyright © 2021 by the Chinese Medical Association.