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UV 254 nm is more efficient than UV 222 nm in inactivating SARS-CoV-2 present in human saliva. Photodiagnosis Photodyn Ther 2022; 39:103015. [PMID: 35843562 PMCID: PMC9281457 DOI: 10.1016/j.pdpdt.2022.103015] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 11/20/2022]
Abstract
Ultraviolet (UV) light can inactivate SARS-CoV-2. However, the practicality of UV light is limited by the carcinogenic potential of mercury vapor-based UV lamps. Recent advances in the development of krypton chlorine (KrCl) excimer lamps hold promise, as these emit a shorter peak wavelength (222 nm), which is highly absorbed by the skin's stratum corneum and can filter out higher wavelengths. In this sense, UV 222 nm irradiation for the inactivation of virus particles in the air and surfaces is a potentially safer option as a germicidal technology. However, these same physical properties make it harder to reach microbes present in complex solutions, such as saliva, a critical source of SARS-CoV-2 transmission. We provide the first evaluation for using a commercial filtered KrCl excimer light source to inactivate SARS-CoV-2 in saliva spread on a surface. A conventional germicidal lamp (UV 254 nm) was also evaluated under the same condition. Using plaque-forming units (PFU) and Median Tissue Culture Infectious Dose (TCID50) per milliliter we found that 99.99% viral clearance (LD99.99) was obtained with 106.3 mJ/cm2 of UV 222 nm for virus in DMEM and 2417 mJ/cm2 for virus in saliva. Additionally, our results showed that the UV 254 nm had a greater capacity to inactivate the virus in both vehicles. Effective (after discounting light absorption) LD99.99 of UV 222 nm on the virus in saliva was ∼30 times higher than the value obtained with virus in saline solution (PBS), we speculated that saliva might be protecting the virus from surface irradiation in ways other than just by intensity attenuation of UV 222 nm. Due to differences between UV 222/254 nm capacities to interact and be absorbed by molecules in complex solutions, a higher dose of 222 nm will be necessary to reduce viral load in surfaces with contaminated saliva.
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Islam MA, Ikeguchi A, Naide T. Effectiveness of an air cleaner device in reducing aerosol numbers and airborne bacteria from an enclosed type dairy barn. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:53022-53035. [PMID: 35277823 DOI: 10.1007/s11356-022-19514-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
There is growing pressure to find technically feasible and economically viable solutions in reducing emissions of pollutants from various occupational settings to minimise environmental pollution. Hence, it is essential to develop and test methods for controlling pollutants from occupational backgrounds. We have tested an air cleaner device in reducing aerosol numbers by filtration and airborne bacteria by photocatalysis from an enclosed type dairy barn. Here, we had shown a significant reduction of larger size aerosol numbers (2.0-10.0 µm) and airborne total aerobic bacteria and Staphylococcus aureus (S. aureus) and complete clearance of Escherichia coli (E. coli) in the exhaust air of the air cleaner device. A greater 8.05% and 61.56% reduction of 5.0-10.0 µm aerosol numbers and airborne E. coli, respectively, were observed in the instantly treated central air of the dairy barn. We had found an increasing trend of aerosol numbers and airborne bacteria concentrations in the central air of the dairy barn after stopping the air cleaner device. We also had observed increased bacterial load in the filter paper of the air treatment chamber of the air cleaner device with the advancement of cleaning time. These findings are essential to validate air cleanings from various types of dairy microenvironments.
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Affiliation(s)
- Md Aminul Islam
- Department of Agricultural and Environmental Engineering, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan.
- Department of Medicine, Faculty of Veterinary Medicine and Animal Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, 1706, Bangladesh.
| | - Atsuo Ikeguchi
- Department of Environmental Engineering, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, 321-8505, Japan
| | - Takanori Naide
- Earth Environmental Service Co., Ltd., 17 Kanda-konyacho, Chiyodaku, Tokyo, 101-0035, Japan
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Romano G, Insero G, Marrugat SN, Fusi F. Innovative light sources for phototherapy. Biomol Concepts 2022; 13:256-271. [DOI: 10.1515/bmc-2022-0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 05/03/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
The use of light for therapeutic purposes dates back to ancient Egypt, where the sun itself was an innovative source, probably used for the first time to heal skin diseases. Since then, technical innovation and advancement in medical sciences have produced newer and more sophisticated solutions for light-emitting sources and their applications in medicine. Starting from a brief historical introduction, the concept of innovation in light sources is discussed and analysed, first from a technical point of view and then in the light of their fitness to improve existing therapeutic protocols or propose new ones. If it is true that a “pure” technical advancement is a good reason for innovation, only a sub-system of those advancements is innovative for phototherapy. To illustrate this concept, the most representative examples of innovative light sources are presented and discussed, both from a technical point of view and from the perspective of their diffusion and applications in the clinical field.
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Affiliation(s)
- Giovanni Romano
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
| | - Giacomo Insero
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
- National Research Council, National Institute of Optics (CNR-INO) , Via Carrara 1 , 50019 Sesto Fiorentino , FI , Italy
| | - Santi Nonell Marrugat
- Institut Quimic de Sarria, Universidad Ramon Llull , Via Augusta 390 , 08017 Barcelona , Spain
| | - Franco Fusi
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
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Debnath S, Islam M. Disinfection chain: A novel method for cheap reusable and chemical free disinfection of public places from SARS-CoV-2. ISA TRANSACTIONS 2022; 124:176-181. [PMID: 33832708 PMCID: PMC8006197 DOI: 10.1016/j.isatra.2021.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 02/21/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Recently, Governments of several countries are taking steps to unlock their countries from the lockdown state to avoid the adverse effect on economy. Disinfection chains of Ultraviolet (UV)-C lamps supported by holding stands have been placed between the space of object columns for exposure-based disinfection. These chains can be folded easily for carrying purpose. Also, the length of the system can be varied depending upon the requirement. This simple system may be used for cheap, reusable and chemical free disinfection of public places. This system is also suitable to destroy the airborne viruses. But the process of disinfection must be performed in absence of human to avoid the harmful effect of UV rays on skin.
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Affiliation(s)
- Sushanta Debnath
- Department of Electrical Engineering, Gomati District Polytechnic, Udaipur, Tripura, 799013, India.
| | - Mohiul Islam
- Department of ECE, CMR College of Engineering & Technology, Hyderabad, Telangana, 501401, India.
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55
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Action Spectra of Bacteria and Purification of Pollutant Water at Faucets Using a Water Waveguide Method. WATER 2022. [DOI: 10.3390/w14091394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ultraviolet (UV) radiation treatment is an effective method for purifying pollutant water contaminated with bacteria and/or chemicals. As an emerging technology, purification by deep ultraviolet light-emitting diodes (DUV-LEDs) is promising. Few studies have used the point-source characteristics of LEDs and have instead replaced mercury vapor lamps with LEDs. Here, we show our recent progress in the instantaneous purification of contaminated water by combining the point-source characteristics of DUV-LEDs with a water waveguide (WW). Before the demonstration, we determined the efficacy of disinfection as a function of irradiation wavelength (action spectra) by constructing a wavelength tunable DUV light source. We found that, as a function of irradiation wavelength, there is a strong correlation between the dose-based inactivation rate constants and deoxyribonucleic acid (DNA) absorbance. Based on this correlation, the emission wavelength of 265 nm was determined as the most effective wavelength for disinfecting water contaminated with bacteria. Instantaneous 2-log disinfection levels of water contaminated with Escherichia coli O1 or Pseudomonas aeruginosa were demonstrated by using the DUV-LED WW method. We also discuss how far-UVC radiation shorter than 230 nm, which has recently been attracting attention and is known as a safe and effective disinfection wavelength for the human body, cannot give a higher-dose-based inactivation rate constant compared to that of 265 nm irradiation due to the larger absorption coefficient of water with a wavelength shorter than 230 nm.
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Thornton GM, Fleck BA, Fleck N, Kroeker E, Dandnayak D, Zhong L, Hartling L. The impact of heating, ventilation, and air conditioning design features on the transmission of viruses, including the 2019 novel coronavirus: A systematic review of ultraviolet radiation. PLoS One 2022; 17:e0266487. [PMID: 35395010 PMCID: PMC8992995 DOI: 10.1371/journal.pone.0266487] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 03/22/2022] [Indexed: 01/14/2023] Open
Abstract
Respiratory viruses are capable of transmitting via an aerosol route. Emerging evidence suggests that SARS-CoV-2 which causes COVID-19 can be spread through airborne transmission, particularly in indoor environments with poor ventilation. Heating, ventilation, and air conditioning (HVAC) systems can play a role in mitigating airborne virus transmission. Ultraviolet germicidal irradiation (UVGI), a feature that can be incorporated into HVAC systems, can be used to impede the ability of viruses to replicate and infect a host. We conducted a systematic review of the scientific literature examining the effectiveness of HVAC design features in reducing virus transmission-here we report results for ultraviolet (UV) radiation. We followed international standards for conducting systematic reviews and developed an a priori protocol. We conducted a comprehensive search to January 2021 of published and grey literature using Ovid MEDLINE, Compendex, and Web of Science Core. Two reviewers were involved in study selection, data extraction, and risk of bias assessments. We presented study characteristics and results in evidence tables, and synthesized results across studies narratively. We identified 32 relevant studies published between 1936 and 2020. Research demonstrates that: viruses and bacteriophages are inactivated by UV radiation; increasing UV dose is associated with decreasing survival fraction of viruses and bacteriophages; increasing relative humidity is associated with decreasing susceptibility to UV radiation; UV dose and corresponding survival fraction are affected by airflow pattern, air changes per hour, and UV device location; and UV radiation is associated with decreased transmission in both animal and human studies. While UV radiation has been shown to be effective in inactivating viruses and reducing disease transmission, practical implementation of UVGI in HVAC systems needs to consider airflow patterns, air changes per hour, and UV device location. The majority of the scientific literature is comprised of experimental, laboratory-based studies. Further, a variety of viruses have been examined; however, there are few studies of coronaviruses and none to date of SARS-CoV-2. Future field studies of UVGI systems could address an existing research gap and provide important information on system performance in real-world situations, particularly in the context of the current COVID-19 pandemic. This comprehensive synthesis of the scientific evidence examining the impact of UV radiation on virus transmission can be used to guide implementation of systems to mitigate airborne spread and identify priorities for future research. Trial registration PROSPERO 2020 CRD42020193968.
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Affiliation(s)
- Gail M. Thornton
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Brian A. Fleck
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Natalie Fleck
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Emily Kroeker
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Dhyey Dandnayak
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Lexuan Zhong
- Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Lisa Hartling
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada
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Freeman S, Kibler K, Lipsky Z, Jin S, German GK, Ye K. Systematic evaluating and modeling of SARS-CoV-2 UVC disinfection. Sci Rep 2022; 12:5869. [PMID: 35393480 PMCID: PMC8988105 DOI: 10.1038/s41598-022-09930-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/29/2022] [Indexed: 11/09/2022] Open
Abstract
The ongoing COVID-19 global pandemic has necessitated evaluating various disinfection technologies for reducing viral transmission in public settings. Ultraviolet (UV) radiation can inactivate pathogens and viruses but more insight is needed into the performance of different UV wavelengths and their applications. We observed greater than a 3-log reduction of SARS-CoV-2 infectivity with a dose of 12.5 mJ/cm2 of 254 nm UV light when the viruses were suspended in PBS, while a dose of 25 mJ/cm2 was necessary to achieve a similar reduction when they were in an EMEM culture medium containing 2%(v/v) FBS, highlighting the critical effect of media in which the virus is suspended, given that SARS-CoV-2 is always aerosolized when airborne or deposited on a surface. It was found that SARS-CoV-2 susceptibility (a measure of the effectiveness of the UV light) in a buffer such as PBS was 4.4-fold greater than that in a cell culture medium. Furthermore, we discovered the attenuation of UVC disinfection by amino acids, vitamins, and niacinamide, highlighting the importance of determining UVC dosages under a condition close to aerosols that wrap the viruses. We developed a disinfection model to determine the effect of the environment on UVC effectiveness with three different wavelengths, 222 nm, 254 nm, and 265 nm. An inverse correlation between the liquid absorbance and the viral susceptibility was observed. We found that 222 nm light was most effective at reducing viral infectivity in low absorbing liquids such as PBS, whereas 265 nm light was most effective in high absorbing liquids such as cell culture medium. Viral susceptibility was further decreased in N95 masks with 222 nm light being the most effective. The safety of 222 nm was also studied. We detected changes to the mechanical properties of the stratum corneum of human skins when the 222 nm accumulative exposure exceeded 50 J/cm2.The findings highlight the need to evaluate each UV for a given application, as well as limiting the dose to the lowest dose necessary to avoid unnecessary exposure to the public.
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Affiliation(s)
- Sebastian Freeman
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), PO Box 6000, Binghamton, NY, 13902, USA.,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Karen Kibler
- Biodesign Institute, Arizona State University, McAllister Ave, Tempe, AZ, 85281, USA
| | - Zachary Lipsky
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), PO Box 6000, Binghamton, NY, 13902, USA
| | - Sha Jin
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), PO Box 6000, Binghamton, NY, 13902, USA.,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Guy K German
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), PO Box 6000, Binghamton, NY, 13902, USA.,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Kaiming Ye
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), PO Box 6000, Binghamton, NY, 13902, USA. .,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA.
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58
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Inactivation Rates for Airborne Human Coronavirus by Low Doses of 222 nm Far-UVC Radiation. Viruses 2022; 14:v14040684. [PMID: 35458414 PMCID: PMC9030991 DOI: 10.3390/v14040684] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 12/22/2022] Open
Abstract
Recent research using UV radiation with wavelengths in the 200–235 nm range, often referred to as far-UVC, suggests that the minimal health hazard associated with these wavelengths will allow direct use of far-UVC radiation within occupied indoor spaces to provide continuous disinfection. Earlier experimental studies estimated the susceptibility of airborne human coronavirus OC43 exposed to 222-nm radiation based on fitting an exponential dose–response curve to the data. The current study extends the results to a wider range of doses of 222 nm far-UVC radiation and uses a computational model coupling radiation transport and computational fluid dynamics to improve dosimetry estimates. The new results suggest that the inactivation of human coronavirus OC43 within our exposure system is better described using a bi-exponential dose–response relation, and the estimated susceptibility constant at low doses—the relevant parameter for realistic low dose rate exposures—was 12.4 ± 0.4 cm2/mJ, which described the behavior of 99.7% ± 0.05% of the virus population. This new estimate is more than double the earlier susceptibility constant estimates that were based on a single-exponential dose response. These new results offer further evidence as to the efficacy of far-UVC to inactivate airborne pathogens.
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59
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Eadie E, Hiwar W, Fletcher L, Tidswell E, O'Mahoney P, Buonanno M, Welch D, Adamson CS, Brenner DJ, Noakes C, Wood K. Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber. Sci Rep 2022; 12:4373. [PMID: 35322064 PMCID: PMC8943125 DOI: 10.1038/s41598-022-08462-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/07/2022] [Indexed: 12/04/2022] Open
Abstract
Many infectious diseases, including COVID-19, are transmitted by airborne pathogens. There is a need for effective environmental control measures which, ideally, are not reliant on human behaviour. One potential solution is Krypton Chloride (KrCl) excimer lamps (often referred to as Far-UVC), which can efficiently inactivate pathogens, such as coronaviruses and influenza, in air. Research demonstrates that when KrCl lamps are filtered to remove longer-wavelength ultraviolet emissions they do not induce acute reactions in the skin or eyes, nor delayed effects such as skin cancer. While there is laboratory evidence for Far-UVC efficacy, there is limited evidence in full-sized rooms. For the first time, we show that Far-UVC deployed in a room-sized chamber effectively inactivates aerosolised Staphylococcus aureus. At a room ventilation rate of 3 air-changes-per-hour (ACH), with 5 filtered-sources the steady-state pathogen load was reduced by 98.4% providing an additional 184 equivalent air changes (eACH). This reduction was achieved using Far-UVC irradiances consistent with current American Conference of Governmental Industrial Hygienists threshold limit values for skin for a continuous 8-h exposure. Our data indicate that Far-UVC is likely to be more effective against common airborne viruses, including SARS-CoV-2, than bacteria and should thus be an effective and "hands-off" technology to reduce airborne disease transmission. The findings provide room-scale data to support the design and development of effective Far-UVC systems.
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Affiliation(s)
- Ewan Eadie
- NHS Tayside, Photobiology Unit, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK.
| | - Waseem Hiwar
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Louise Fletcher
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Emma Tidswell
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Paul O'Mahoney
- NHS Tayside, Photobiology Unit, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK
- School of Medicine Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Manuela Buonanno
- Center for Radiological Research, Columbia University Medical Center, New York, NY, USA
| | - David Welch
- Center for Radiological Research, Columbia University Medical Center, New York, NY, USA
| | - Catherine S Adamson
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - David J Brenner
- Center for Radiological Research, Columbia University Medical Center, New York, NY, USA
| | - Catherine Noakes
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Kenneth Wood
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, UK
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Ahmed AAM, Ahmed MH, Saha SK, Ahmed O, Sutradhar A. Optimization algorithms as training approach with hybrid deep learning methods to develop an ultraviolet index forecasting model. STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT : RESEARCH JOURNAL 2022; 36:3011-3039. [PMID: 35228836 PMCID: PMC8868041 DOI: 10.1007/s00477-022-02177-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/09/2022] [Indexed: 06/14/2023]
Abstract
The solar ultraviolet index (UVI) is a key public health indicator to mitigate the ultraviolet-exposure related diseases. This study aimed to develop and compare the performances of different hybridised deep learning approaches with a convolutional neural network and long short-term memory referred to as CLSTM to forecast the daily UVI of Perth station, Western Australia. A complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is incorporated coupled with four feature selection algorithms (i.e., genetic algorithm (GA), ant colony optimization (ACO), particle swarm optimization (PSO), and differential evolution (DEV)) to understand the diverse combinations of the predictor variables acquired from three distinct datasets (i.e., satellite data, ground-based SILO data, and synoptic mode climate indices). The CEEMDAN-CLSTM model coupled with GA appeared to be an accurate forecasting system in capturing the UVI. Compared to the counterpart benchmark models, the results demonstrated the excellent forecasting capability (i.e., low error and high efficiency) of the recommended hybrid CEEMDAN-CLSTM model in apprehending the complex and non-linear relationships between predictor variables and the daily UVI. The study inference can considerably enhance real-time exposure advice for the public and help mitigate the potential for solar UV-exposure-related diseases such as melanoma.
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Affiliation(s)
- A A Masrur Ahmed
- School of Mathematics Physics and Computing, University of Southern Queensland, Springfield, QLD 4300 Australia
| | - Mohammad Hafez Ahmed
- Present Address: Department of Civil and Environmental Engineering, West Virginia University, PO BOX 6103, Morgantown, WV 26506-6103 USA
| | - Sanjoy Kanti Saha
- Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | - Oli Ahmed
- School of Modern Sciences, Leading University, Sylhet, 3112 Bangladesh
| | - Ambica Sutradhar
- School of Modern Sciences, Leading University, Sylhet, 3112 Bangladesh
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61
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Su WL, Lin CP, Huang HC, Wu YK, Yang MC, Chiu SK, Peng MY, Chan MC, Chao YC. Clinical application of 222 nm wavelength ultraviolet C irradiation on SARS CoV-2 contaminated environments. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2022; 55:166-169. [PMID: 35094944 PMCID: PMC8755561 DOI: 10.1016/j.jmii.2021.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/11/2021] [Accepted: 12/25/2021] [Indexed: 11/25/2022]
Abstract
This was a preliminary study on ultraviolet C (UVC) irradiation for SARS-CoV-2-contaminated hospital environments. Forty-eight locations were tested for SARS-CoV-2 using RT-PCR (33.3% contamination rate). After series dosages of 222-nm UVC irradiation, samples from the surfaces were negative at 15 s irradiation at 2 cm length (fluence: 81 mJ/cm2).
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Affiliation(s)
- Wen-Lin Su
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chih-Pei Lin
- Department of Pathology and Laboratory Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Hui-Ching Huang
- Department of Pathology and Laboratory Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan
| | - Yao-Kuang Wu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Mei-Chen Yang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Sheg-Kang Chiu
- Division of Infectious Disease, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan; Infection Control Center, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan
| | - Ming-Yieh Peng
- Division of Infectious Disease, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan; Infection Control Center, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan
| | - Ming-Chin Chan
- Infection Control Center, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan
| | - You-Chen Chao
- School of Medicine, Tzu Chi University, Hualien, Taiwan; Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan.
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62
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Welch D, Aquino de Muro M, Buonanno M, Brenner DJ. Wavelength-dependent DNA Photodamage in a 3-D Human Skin Model over the far-UVC and Germicidal-UVC Wavelength Ranges from 215 to 255 nm. Photochem Photobiol 2022; 98:1167-1171. [PMID: 35104367 PMCID: PMC9544172 DOI: 10.1111/php.13602] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/28/2022] [Indexed: 11/27/2022]
Abstract
The effectiveness of UVC to reduce airborne‐mediated disease transmission is well established. However, conventional germicidal UVC (~254 nm) cannot be used directly in occupied spaces because of the potential for damage to the skin and eye. A recently studied alternative with the potential to be used directly in occupied spaces is far UVC (200–235 nm, typically 222 nm), as it cannot penetrate to the key living cells in the epidermis. Optimal far‐UVC use is hampered by limited knowledge of the precise wavelength dependence of UVC‐induced DNA damage, and thus we have used a monochromatic UVC exposure system to assess wavelength‐dependent DNA damage in a realistic 3‐D human skin model. We exposed a 3‐D human skin model to mono‐wavelength UVC exposures of 100 mJ/cm2, at UVC wavelengths from 215 to 255 nm (5 nm steps). At each wavelength, we measured yields of DNA‐damaged keratinocytes, and their distribution within the layers of the epidermis. No increase in DNA damage was observed in the epidermis at wavelengths from 215 to 235 nm, but at higher wavelengths (240–255 nm) significant levels of DNA damage was observed. These results support use of far‐UVC radiation to safely reduce the risk of airborne disease transmission in occupied locations.
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Affiliation(s)
- David Welch
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Marilena Aquino de Muro
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Manuela Buonanno
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
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Mohamadi F, Fazeli A. A Review on Applications of CFD Modeling in COVID-19 Pandemic. ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING : STATE OF THE ART REVIEWS 2022; 29:3567-3586. [PMID: 35079217 PMCID: PMC8773396 DOI: 10.1007/s11831-021-09706-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 12/28/2021] [Indexed: 05/25/2023]
Abstract
COVID-19 pandemic has started a big challenge to the world health and economy during recent years. Many efforts were made to use the computation fluid dynamic (CFD) approach in this pandemic. CFD was used to understanding the airborne dispersion and transmission of this virus in different situations and buildings. The effect of the different conditions of the ventilation was studied by the CFD modeling to discuss preventing the COVID-19 transmission. Social distancing and using the facial masks were also modeled by the CFD approach to study the effect on reducing dispersion of the microdroplets containing the virus. Most of these recent applications of the CFD were reviewed for COVID-19 in this article. Special applications of the CFD modeling such as COVID-19 microfluidic biosensors, and COVID-19 inactivation using UV radiation were also reviewed in this research. The main findings of each research were also summarized in a table to answer critical questions about the effectiveness levels of applying the COVID-19 health protocols. CFD applications for modeling of COVID-19 dispersion in an airplane cabin, an elevator, a small classroom, a supermarket, an operating room of a hospital, a restaurant, a hospital waiting room, and a children's recovery room in a hospital were discussed briefly in different scenarios. CFD modeling for studying the effect of social distancing with different spaces, using and not using facial masks, difference of sneezing and coughing, different inlet/outlet ventilation layouts, combining air-conditioning and sanitizing machine, and using general or local air-conditioning systems were reviewed.
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Affiliation(s)
- Fateme Mohamadi
- Department of Chemical Engineering, Caspian Faculty of Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Ali Fazeli
- Department of Chemical Engineering, Caspian Faculty of Engineering, College of Engineering, University of Tehran, Tehran, Iran
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Depelteau JS, Renault L, Althof N, Cassidy CK, Mendonça LM, Jensen GJ, Resch GP, Briegel A. UVC inactivation of pathogenic samples suitable for cryo-EM analysis. Commun Biol 2022; 5:29. [PMID: 35017666 PMCID: PMC8752862 DOI: 10.1038/s42003-021-02962-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/07/2021] [Indexed: 12/22/2022] Open
Abstract
Cryo-electron microscopy has become an essential tool to understand structure and function of biological samples. Especially for pathogens, such as disease-causing bacteria and viruses, insights gained by cryo-EM can aid in developing cures. However, due to the biosafety restrictions of pathogens, samples are often treated by chemical fixation to render the pathogen inert, affecting the ultrastructure of the sample. Alternatively, researchers use in vitro or ex vivo models, which are non-pathogenic but lack the complexity of the pathogen of interest. Here we show that ultraviolet-C (UVC) radiation applied at cryogenic temperatures can be used to eliminate or dramatically reduce the infectivity of Vibrio cholerae and the bacterial virus, the ICP1 bacteriophage. We show no discernable structural impact of this treatment of either sample using two cryo-EM methods: cryo-electron tomography followed by sub-tomogram averaging, and single particle analysis (SPA). Additionally, we applied the UVC irradiation to the protein apoferritin (ApoF), which is a widely used test sample for high-resolution SPA studies. The UVC-treated ApoF sample resulted in a 2.1 Å structure indistinguishable from an untreated published map. This research demonstrates that UVC treatment is an effective and inexpensive addition to the cryo-EM sample preparation toolbox. Depelteau et al. present a new method to inactivate cryo-EM samples from pathogenic organisms before imaging using ultraviolet-C radiation in cryogenic conditions. This method allows for the inexpensive preparation of cryo-EM samples with no discernable structural impact of the treatment.
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Affiliation(s)
- Jamie S Depelteau
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands
| | - Ludovic Renault
- Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Nynke Althof
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands
| | - C Keith Cassidy
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Luiza M Mendonça
- Biology and Bioengineering Department, California Institute of Technology, Pasadena, CA, USA.,Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Grant J Jensen
- Biology and Bioengineering Department, California Institute of Technology, Pasadena, CA, USA and Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Guenter P Resch
- Nexperion e.U.-Solutions for Electron Microscopy, Vienna, Austria
| | - Ariane Briegel
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands. .,Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands.
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65
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Luo X, Zhang B, Lu Y, Mei Y, Shen L. Advances in application of ultraviolet irradiation for biofilm control in water and wastewater infrastructure. JOURNAL OF HAZARDOUS MATERIALS 2022; 421:126682. [PMID: 34388918 DOI: 10.1016/j.jhazmat.2021.126682] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 05/26/2023]
Abstract
Biofilms are ubiquitous in aquatic environment. While so far, most of the ultraviolet (UV) disinfection studies focus on planktonic bacteria, and only limited attention has been given to UV irradiation on biofilms. To enrich this knowledge, the present paper reviews the up-to-date studies about applying UV to control biofilms in water and wastewater infrastructure. The development of UV light sources from the conventional mercury lamp to the light emitting diode (LED), and the resistance mechanisms of biofilms to UV are summarized, respectively. Then the feasibility to control biofilms with UV is discussed in terms of three technical routes: causing biofilm slough, inhibiting biofilm formation, and inactivating bacteria in the established biofilm. A comprehensive evaluation of the biofilm-targeted UV technologies currently used or potentially useful in water industry is provided as well, after comparative analyses on single/combined wavelengths, continuous/pulsed irradiation, and instant/chronic disinfection effects. UV LEDs are emerging as competitive light sources because of advantages such as possible selection of wavelengths, adjustable emitting mode and the designable configuration. They still, however, face challenges arising from the low wall plug efficiency and power output. At last, the implementation of the UV-based advanced oxidation processes in controlling biofilms on artificial surfaces is overviewed and their synergistic mechanisms are proposed, which further enlightens the prospective of UV in dealing with the biofilm issue in water infrastructure.
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Affiliation(s)
- Xueru Luo
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Baoping Zhang
- Department of Electronic Engineering, Laboratory of Micro/Nano-Optoelectronics, Xiamen University, Xiamen, Fujian 361005, China.
| | - Yinghua Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Yang Mei
- Department of Electronic Engineering, Laboratory of Micro/Nano-Optoelectronics, Xiamen University, Xiamen, Fujian 361005, China
| | - Liang Shen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
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66
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Tuchin VV, Genina EA, Tuchina ES, Svetlakova AV, Svenskaya YI. Optical clearing of tissues: Issues of antimicrobial phototherapy and drug delivery. Adv Drug Deliv Rev 2022; 180:114037. [PMID: 34752842 DOI: 10.1016/j.addr.2021.114037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/23/2021] [Accepted: 10/28/2021] [Indexed: 02/08/2023]
Abstract
This review presents principles and novelties in the field of tissue optical clearing (TOC) technology, as well as application for optical monitoring of drug delivery and effective antimicrobial phototherapy. TOC is based on altering the optical properties of tissue through the introduction of immersion optical cleaning agents (OCA), which impregnate the tissue of interest. We also analyze various methods and kinetics of delivery of photodynamic agents, nanoantibiotics and their mixtures with OCAs into the tissue depth in the context of antimicrobial and antifungal phototherapy. In vitro and in vivo studies of antimicrobial phototherapies, such as photodynamic, photothermal plasmonic and photocatalytic, are summarized, and the prospects of a new TOC technology for effective killing of pathogens are discussed.
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67
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Fukui T, Niikura T, Oda T, Kumabe Y, Nishiaki A, Kaigome R, Ohashi H, Sasaki M, Igarashi T, Oe K, Hamblin MR, Kuroda R. Safety of 222 nm UVC Irradiation to the Surgical Site in a Rabbit Model. Photochem Photobiol 2022; 98:1365-1371. [PMID: 35313036 PMCID: PMC9790646 DOI: 10.1111/php.13620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/30/2022]
Abstract
For the prevention of surgical site infection (SSI), continuous disinfection could be helpful. Short wavelength ultraviolet radiation C (UVC) is highly bactericidal but shows cytotoxicity. Radiation of UVC with a wavelength of 222 nm to the skin is considered to be safe because it only reaches the stratum corneum. However, the safety of 222 nm irradiation to the surgical field not covered with skin is unknown. The purpose of this study was to examine the safety of 222 nm UVC irradiation on a surgical field in a rabbit model. Five types of tissue were surgically exposed and irradiated with 222 or 254 nm UVC. Immunohistological assessment against cyclobutane pyrimidine dimer (CPD), an index of DNA damage by UVC, was performed. The CPD-positive cell rate was significantly higher in the 254 nm group than in the other groups in all tissues. A 222 nm group showed significantly more CPD than control in fat tissue, but no significant difference in all other tissues. In fat tissue collected 24 h after irradiation, the 254 nm group showed higher CPD than the other groups, while the 222 nm group had reduced to the control level. These data suggest that 222 nm UVC irradiation could be a new method to safely prevent SSI.
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Affiliation(s)
- Tomoaki Fukui
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
| | - Takahiro Niikura
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
| | - Takahiro Oda
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
| | - Yohei Kumabe
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
| | | | | | | | | | | | - Keisuke Oe
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
| | - Michael R. Hamblin
- Laser Research CentreFaculty of Health ScienceUniversity of JohannesburgJohannesburgSouth Africa
| | - Ryosuke Kuroda
- Department of Orthopaedic SurgeryKobe University Graduate School of MedicineKobeJapan
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68
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The effectiveness of commercial household ultraviolet C germicidal devices in Thailand. Sci Rep 2021; 11:23859. [PMID: 34903815 PMCID: PMC8668883 DOI: 10.1038/s41598-021-03326-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 11/29/2021] [Indexed: 11/20/2022] Open
Abstract
Ultraviolet C (UVC), or ultraviolet germicidal irradiation (UVGI), is known for its effective air, water, and surface disinfectant properties. With the rise of global awareness about public sanitation and personal hygiene due to the emergence of the current coronavirus disease 2019 pandemic, several applications of UVC were introduced to the commercial market. The present experimental study aimed to evaluate the effectiveness of commercial household UVC germicidal devices for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation. Ten UVC devices were included in the study comprising of 7 low-pressure mercury lamps (LPMLs) and 3 UVC- light-emitting diodes (LEDs). Considering applications, 3 were handheld UVGI surface disinfection equipment, 4 were UVGI disinfection chambers, and 3 were movable UVGI air and surface purifiers. To determine SARS-CoV-2 inactivation performance, UVC irradiance (mW/cm2) was measured 3 times repeatedly at distance and duration corresponding to manufacturers’ usage instructions. The required UVC dosage could not be achieved by either of UVC-LED devices (1 handheld UVGI surface disinfection equipment and 2 UVGI disinfection chambers). Five of seven LPMLs can sufficiently emit UVC irradiance for SARS-CoV-2-inactivation. A lack of standardization in the distance and cycle duration for each UVC application was observed. Standard usage guidelines for UVC devices are required to improve the effectiveness of UVC irradiance for SARS-CoV-2 inactivation as well as to minimize the potential side effects of UVC.
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69
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Besegato JF, de Melo PBG, Tamae PE, Alves APAR, Rondón LF, Leanse LG, Dos Anjos C, Casarin HH, Chinelatti MA, Faria G, Dai T, Bagnato VS, Rastelli ANDS. How can biophotonics help dentistry to avoid or minimize cross infection by SARS-CoV-2? Photodiagnosis Photodyn Ther 2021; 37:102682. [PMID: 34910994 PMCID: PMC8666148 DOI: 10.1016/j.pdpdt.2021.102682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 12/23/2022]
Abstract
Biophotonics is defined as the combination of biology and photonics (the physical science of the light). It is a general term for all techniques that deal with the interaction between biological tissues/cells and photons (light). Biophotonics offers a great variety of techniques that can facilitate the early detection of diseases and promote innovative theragnostic approaches. As the COVID-19 infection can be transmitted due to the face-to-face communication, droplets and aerosol inhalation and the exposure to saliva, blood, and other body fluids, as well as the handling of sharp instruments, dental practices are at increased risk of infection. In this paper, a literature review was performed to explore the application of Biophotonics approaches in Dentistry focusing on the COVID-19 pandemic and how they can contribute to avoid or minimize the risks of infection in a dental setting. For this, search-related papers were retrieved from PubMED, Scielo, Google Schoolar, and American Dental Association and Centers for Disease Control and Prevention databases. The body of evidence currently available showed that Biophotonics approaches can reduce microorganism load, decontaminate surfaces, air, tissues, and minimize the generation of aerosol and virus spreading by minimally invasive, time-saving, and alternative techniques in general. However, each clinical situation must be individually evaluated regarding the benefits and drawbacks of these approaches, but always pursuing less-invasive and less aerosol-generating procedures, especially during the COVID-19 pandemic.
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Affiliation(s)
- João Felipe Besegato
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil
| | - Priscila Borges Gobbo de Melo
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil
| | - Patrícia Eriko Tamae
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil
| | - Ana Paula Aparecida Raimundo Alves
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil
| | - Luis Felipe Rondón
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil
| | - Leon G Leanse
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, University of Harvard, Boston, MA 02114, USA.
| | - Carolina Dos Anjos
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, University of Harvard, Boston, MA 02114, USA.
| | - Heitor Hussni Casarin
- Dentistry School, Central Paulista University Center - UNICEP, São Carlos 13563-470, SP, Brazil
| | | | - Gisele Faria
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil.
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, University of Harvard, Boston, MA 02114, USA.
| | | | - Alessandra Nara de Souza Rastelli
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Araraquara 14801-903, SP, Brazil.
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70
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Tatsuno I, Niimi Y, Tomita M, Terashima H, Hasegawa T, Matsumoto T. Mechanism of transient photothermal inactivation of bacteria using a wavelength-tunable nanosecond pulsed laser. Sci Rep 2021; 11:22310. [PMID: 34785646 PMCID: PMC8595719 DOI: 10.1038/s41598-021-01543-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/29/2021] [Indexed: 11/24/2022] Open
Abstract
There is a great demand for novel disinfection technologies to inactivate various pathogenic viruses and bacteria. In this situation, ultraviolet (UVC) disinfection technologies seem to be promising because biocontaminated air and surfaces are the major media for disease transmission. However, UVC is strongly absorbed by human cells and protein components; therefore, there are concerns about damaging plasma components and causing dermatitis and skin cancer. To avoid these concerns, in this study, we demonstrate that the efficient inactivation of bacteria is achieved by visible pulsed light irradiation. The principle of inactivation is based on transient photothermal heating. First, we provide experimental confirmation that extremely high temperatures above 1000 K can be achieved by pulsed laser irradiation. Evidence of this high temperature is directly confirmed by melting gold nanoparticles (GNPs). Inorganic GNPs are used because of their well-established thermophysical properties. Second, we show inactivation behaviour by pulsed laser irradiation. This inactivation behaviour cannot be explained by a simple optical absorption effect. We experimentally and theoretically clarify this inactivation mechanism based on both optical absorption and scattering effects. We find that scattering and absorption play an important role in inactivation because the input irradiation is inherently scattered by the bacteria; therefore, the dose that bacteria feel is reduced. This scattering effect can be clearly shown by a technique that combines stained Escherichia coli and site selective irradiation obtained by a wavelength tunable pulsed laser. By measuring Live/Dead fluorescence microscopy images, we show that the inactivation attained by the transient photothermal heating is possible to instantaneously and selectively kill microorganisms such as Escherichia coli bacteria. Thus, this method is promising for the site selective inactivation of various pathogenic viruses and bacteria in a safe and simple manner.
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Affiliation(s)
- Ichiro Tatsuno
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Yuna Niimi
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Makoto Tomita
- Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Hiroshi Terashima
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Tadao Hasegawa
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Takahiro Matsumoto
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan.
- Graduate School of Design and Architecture, Nagoya City University, Nagoya, 464-0083, Japan.
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71
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Otake M, Okamoto Yoshiyama K, Yamaguchi H, Hidema J. 222 nm ultraviolet radiation C causes more severe damage to guard cells and epidermal cells of Arabidopsis plants than does 254 nm ultraviolet radiation. Photochem Photobiol Sci 2021; 20:1675-1683. [PMID: 34734375 PMCID: PMC8565646 DOI: 10.1007/s43630-021-00123-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/19/2021] [Indexed: 11/26/2022]
Abstract
Lamps that emit 222 nm short-wavelength ultraviolet (UV) radiation can be safely used for sterilization without harming human health. However, there are few studies on the effects of 222 nm UVC (222-UVC) radiation exposure on plants compared with the effects of germicidal lamps emitting primarily 254 nm UVC (254-UVC) radiation. We investigated the growth inhibition and cell damage caused by 222-UVC exposure to Arabidopsis plants, especially mitochondrial dynamics, which is an index of damage caused by UVB radiation. Growth inhibition resulted from 254-UVC or 222-UVC exposure depending on the dose of UVC radiation. However, with respect to the phenotype of 222-UVC-irradiated plants, the leaves curled under 1 kJ m−2 and were markedly bleached under 10 kJ m−2 compared with those of plants irradiated with 254-UVC. The cellular state, especially the mitochondrial dynamics, of epidermal and mesophyll cells of Arabidopsis leaves exposed to 254-UVC or 222-UVC radiation was investigated using Arabidopsis plants expressing mitochondrial matrix-targeted yellow fluorescent protein (MT-YFP) under the control of Pro35S to visualize the mitochondria. 222-UVC (1 or 5 kJ m−2) severely damaged the guard cells within the epidermis, and YFP signals and chloroplast autofluorescence in guard cells within the epidermis exposed to 222-UVC (1 or 5 kJ m−2) were not detected compared with those in cells exposed to 254-UVC radiation. In addition, 222-UVC irradiation led to mitochondrial fragmentation in mesophyll cells, similar to the effects of 254-UVC exposure. These results suggest that 222-UVC severely damages guard cells and epidermal cells and that such damage might have resulted in growth inhibition.
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Affiliation(s)
- Momo Otake
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan
| | - Kaoru Okamoto Yoshiyama
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan
| | - Hiroko Yamaguchi
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan
| | - Jun Hidema
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan.
- Division for the Establishment of Frontier Sciences of the Organization for Advanced Studies, Tohoku University, Sendai, 980-8577, Japan.
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Chen Y, Ben J, Xu F, Li J, Chen Y, Sun X, Li D. Review on the Progress of AlGaN-based Ultraviolet Light-Emitting Diodes. FUNDAMENTAL RESEARCH 2021. [DOI: 10.1016/j.fmre.2021.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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73
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Bhardwaj SK, Singh H, Deep A, Khatri M, Bhaumik J, Kim KH, Bhardwaj N. UVC-based photoinactivation as an efficient tool to control the transmission of coronaviruses. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148548. [PMID: 34465056 PMCID: PMC8238411 DOI: 10.1016/j.scitotenv.2021.148548] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/28/2021] [Accepted: 06/15/2021] [Indexed: 05/04/2023]
Abstract
The ongoing COVID-19 pandemic made us re-realize the importance of environmental disinfection and sanitation in indoor areas, hospitals, and clinical rooms. UVC irradiation of high energy and short wavelengths, especially in the 200-290-nm range possesses the great potential for germicidal disinfection. These properties of UVC allow to damage or destruct the nucleic acids (DNA/RNA) in diverse microbes (e.g., bacteria, fungi, and viruses). UVC light can hence be used as a promising tool for prevention and control of their infection or transmission. The present review offers insights into the historical perspective, mode of action, and recent advancements in the application of UVC-based antiviral therapy against coronaviruses (including SARS CoV-2). Moreover, the application of UVC lights in the sanitization of healthcare units, public places, medical instruments, respirators, and personal protective equipment (PPE) is also discussed. This article, therefore, is expected to deliver a new path for the developments of UVC-based viricidal approach.
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Affiliation(s)
- Sanjeev K Bhardwaj
- Department of Nanomaterials and Application Technology, Center of Innovative and Applied Bioprocessing, Sector 81 (Knowledge City), S.A.S. Nagar 140306, Punjab, India
| | - Harpreet Singh
- Department of Biotechnology, University Institute of Engineering Technology (UIET), Panjab University, Chandigarh, India
| | - Akash Deep
- Central Scientific Instruments Organisation, Sector 30-C, Chandigarh 160030, India
| | - Madhu Khatri
- Department of Biotechnology, University Institute of Engineering Technology (UIET), Panjab University, Chandigarh, India
| | - Jayeeta Bhaumik
- Department of Nanomaterials and Application Technology, Center of Innovative and Applied Bioprocessing, Sector 81 (Knowledge City), S.A.S. Nagar 140306, Punjab, India
| | - Ki-Hyun Kim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea.
| | - Neha Bhardwaj
- Department of Biotechnology, University Institute of Engineering Technology (UIET), Panjab University, Chandigarh, India.
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Chandran KM, Ramamurthy PC, Kanjo K, Narayan R, Menon SR. Efficacy of Ultraviolet-C Devices for the Disinfection of Personal Protective Equipment Fabrics and N95 Respirators. JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 2021; 126:126023. [PMID: 36475082 PMCID: PMC9681524 DOI: 10.6028/jres.126.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/26/2021] [Indexed: 06/15/2023]
Abstract
Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, a plethora of ultraviolet-C (UV-C) disinfection products have come to market, especially in emerging economies. UV-C-based disinfection products for mobile phones, food packaging, face masks and personal protective equipment (PPE), and other everyday objects are available in popular electronic-commerce platforms as consumer products. Product designers from multinational to startup companies began to design UV-C disinfection products but had no prior-art reference, user feedback, or validation of product efficacy, which are important stages in product design. A UV-C disinfection product cannot be assessed by most consumers for its viricidal efficacy. Many firms entered the domain of UV-C products and were unaware of the necessary validation requirements. Lack of availability and access to virology laboratories, due to lockdowns in countries, and lack of standards and certification for UV-C disinfection products limited product designers and firms in benchmarking their UV-C-based devices before market release. This work evaluates two UV-C disinfection devices for viricidal efficacy on PPE fabric and National Institute for Occupational Safety and Health (NIOSH)-certified N95 respirators through controlled experiments using the H1N1 virus, which is enveloped and is transmitted via the respiratory route similar to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of COVID-19. The experiment also evaluated the effectiveness of chemical disinfectants along with and versus UV-C disinfection. Experiments for material selection, UV dose calculation, and UV endurance of PPE samples to be disinfected are also discussed. The outcome of this work establishes a systematic method to validate the efficacy of UV-C disinfection products. The design guidelines would benefit product designers in designing UV-C-based disinfection products.
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Affiliation(s)
| | | | - Kawkab Kanjo
- Indian Institute of Science,
Bangalore 560012,
India
| | - Rohan Narayan
- Indian Institute of Science,
Bangalore 560012,
India
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Buchan AG, Yang L, Welch D, Brenner DJ, Atkinson KD. Improved estimates of 222 nm far-UVC susceptibility for aerosolized human coronavirus via a validated high-fidelity coupled radiation-CFD code. Sci Rep 2021; 11:19930. [PMID: 34620923 PMCID: PMC8497589 DOI: 10.1038/s41598-021-99204-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
Transmission of SARS-CoV-2 by aerosols has played a significant role in the rapid spread of COVID-19 across the globe. Indoor environments with inadequate ventilation pose a serious infection risk. Whilst vaccines suppress transmission, they are not 100% effective and the risk from variants and new viruses always remains. Consequently, many efforts have focused on ways to disinfect air. One such method involves use of minimally hazardous 222 nm far-UVC light. Whilst a small number of controlled experimental studies have been conducted, determining the efficacy of this approach is difficult because chamber or room geometry, and the air flow within them, influences both far-UVC illumination and aerosol dwell times. Fortunately, computational multiphysics modelling allows the inadequacy of dose-averaged assessment of viral inactivation to be overcome in these complex situations. This article presents the first validation of the WYVERN radiation-CFD code for far-UVC air-disinfection against survival fraction measurements, and the first measurement-informed modelling approach to estimating far-UVC susceptibility of viruses in air. As well as demonstrating the reliability of the code, at circa 70% higher, our findings indicate that aerosolized human coronaviruses are significantly more susceptible to far-UVC than previously thought.
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Affiliation(s)
- Andrew G Buchan
- School of Engineering and Materials Science, Queen Mary University of London, E1 4NS, London, UK.
| | - Liang Yang
- School of Water, Energy and Environment (SWEE), Cranfield University, Bedford, MK43 0AL, UK
| | - David Welch
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Kirk D Atkinson
- Faculty of Energy Systems and Nuclear Science, Ontario Tech University, Oshawa, Ontario, L1G 0C5, Canada
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76
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Wood K, Wood A, Peñaloza C, Eadie E. Turn Up the Lights, Leave them On and Shine them All Around-Numerical Simulations Point the Way to more Efficient Use of Far-UVC Lights for the Inactivation of Airborne Coronavirus. Photochem Photobiol 2021; 98:471-483. [PMID: 34599612 PMCID: PMC8661964 DOI: 10.1111/php.13523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 09/15/2021] [Indexed: 01/12/2023]
Abstract
It has been demonstrated in laboratory environments that ultraviolet‐C (UVC) light is effective at inactivating airborne viruses. However, due to multiple parameters, it cannot be assumed that the air inside a room will be efficiently disinfected by commercial germicidal ultraviolet (GUV) systems. This research utilizes numerical simulations of airflow, viral spread, inactivation by UVC and removal by mechanical ventilation in a typical classroom. The viral load in the classroom is compared for conventional upper‐room GUV and the emerging “Far‐UVC.” In our simulated environment, GUV is shown to be effective in both well and poorly ventilated rooms, with greatest benefit in the latter. At current exposure limits, 18 commercial Far‐UVC systems were as effective at reducing viral load as a single upper‐room GUV. Improvements in Far‐UVC irradiation distribution and recently proposed increases to exposure limits would dramatically increase the efficacy of Far‐UVC devices. Modifications to current Far‐UVC devices, which would improve their real‐world efficacy, could be implemented now without requiring legislative change. The prospect of increased safety limits coupled with our suggested technological modifications could usher in a new era of safe and rapid whole room air disinfection in occupied indoor spaces.
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Affiliation(s)
- Kenneth Wood
- SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, UK
| | | | - Camilo Peñaloza
- SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, UK
| | - Ewan Eadie
- NHS Tayside, Photobiology Unit, Ninewells Hospital and Medical School, Dundee, UK
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77
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Jmerik V, Nechaev D, Orekhova K, Prasolov N, Kozlovsky V, Sviridov D, Zverev M, Gamov N, Grieger L, Wang Y, Wang T, Wang X, Ivanov S. Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240-270 nm Spectral Range. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2553. [PMID: 34684994 PMCID: PMC8537242 DOI: 10.3390/nano11102553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022]
Abstract
Monolayer (ML)-scale GaN/AlN multiple quantum well (MQW) structures for electron-beam-pumped ultraviolet (UV) emitters are grown on c-sapphire substrates by using plasma-assisted molecular beam epitaxy under controllable metal-rich conditions, which provides the spiral growth of densely packed atomically smooth hillocks without metal droplets. These structures have ML-stepped terrace-like surface topology in the entire QW thickness range from 0.75-7 ML and absence of stress at the well thickness below 2 ML. Satisfactory quantum confinement and mitigating the quantum-confined Stark effect in the stress-free MQW structures enable one to achieve the relatively bright UV cathodoluminescence with a narrow-line (~15 nm) in the sub-250-nm spectral range. The structures with many QWs (up to 400) exhibit the output optical power of ~1 W at 240 nm, when pumped by a standard thermionic-cathode (LaB6) electron gun at an electron energy of 20 keV and a current of 65 mA. This power is increased up to 11.8 W at an average excitation energy of 5 µJ per pulse, generated by the electron gun with a ferroelectric plasma cathode at an electron-beam energy of 12.5 keV and a current of 450 mA.
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Affiliation(s)
- Valentin Jmerik
- Centre of Nanoheterostructure Physics, Ioffe Institute, 26 Politekhnicheskaya, 194021 St. Petersburg, Russia; (D.N.); (K.O.); (N.P.); (S.I.)
| | - Dmitrii Nechaev
- Centre of Nanoheterostructure Physics, Ioffe Institute, 26 Politekhnicheskaya, 194021 St. Petersburg, Russia; (D.N.); (K.O.); (N.P.); (S.I.)
| | - Kseniya Orekhova
- Centre of Nanoheterostructure Physics, Ioffe Institute, 26 Politekhnicheskaya, 194021 St. Petersburg, Russia; (D.N.); (K.O.); (N.P.); (S.I.)
| | - Nikita Prasolov
- Centre of Nanoheterostructure Physics, Ioffe Institute, 26 Politekhnicheskaya, 194021 St. Petersburg, Russia; (D.N.); (K.O.); (N.P.); (S.I.)
| | - Vladimir Kozlovsky
- Laboratory for Cathode Ray Pumped Lasers, P. N. Lebedev Physical Institute, Leninsky Ave. 53, 119991 Moscow, Russia; (V.K.); (D.S.); (M.Z.)
| | - Dmitry Sviridov
- Laboratory for Cathode Ray Pumped Lasers, P. N. Lebedev Physical Institute, Leninsky Ave. 53, 119991 Moscow, Russia; (V.K.); (D.S.); (M.Z.)
| | - Mikhail Zverev
- Laboratory for Cathode Ray Pumped Lasers, P. N. Lebedev Physical Institute, Leninsky Ave. 53, 119991 Moscow, Russia; (V.K.); (D.S.); (M.Z.)
- Department of Physics, Moscow Technological University, Vernadsky Ave. 78, 119454 Moscow, Russia;
| | - Nikita Gamov
- Department of Physics, Moscow Technological University, Vernadsky Ave. 78, 119454 Moscow, Russia;
| | - Lars Grieger
- Application Competence Center, Malvern Panalytical B.V., Lelyweg 1 (7602 EA), P.O. Box 13, 7600 AA Almelo, The Netherlands;
| | - Yixin Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nanooptoelectronics, School of Physics, Peking University, Beijing 100871, China; (Y.W.); (X.W.)
| | - Tao Wang
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China;
| | - Xinqiang Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nanooptoelectronics, School of Physics, Peking University, Beijing 100871, China; (Y.W.); (X.W.)
| | - Sergey Ivanov
- Centre of Nanoheterostructure Physics, Ioffe Institute, 26 Politekhnicheskaya, 194021 St. Petersburg, Russia; (D.N.); (K.O.); (N.P.); (S.I.)
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78
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Yang J. Real Nano "Light Vaccine" Will Benefit to COVID-19 Pandemic Control. NANO-MICRO LETTERS 2021; 13:185. [PMID: 34480230 PMCID: PMC8415433 DOI: 10.1007/s40820-021-00723-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 02/08/2023]
Abstract
This highlight presents a recent technique of “Light Vaccine” for COVID-19 pandemic control. Though this technique has the germicidal advantage to SARS-CoV-2, its shortcomings will limit the wide and in-depth application. We make a perspective of real nano light vaccine, which will play an important role in the prevention and control of COVID-19. Briefly, This flow chart described the MWCNT was fabricated with strong acid and base conditional mixture in order to achieve the p-WCNT (chemical process); then modified with RNA layse and receptor binding domain (RBD) by covalent conjugation and physical absorption to get f-WCNT (functionalization); thereafter, f-WCNT was used in the multi-cell culture system interacting with SARS-CoV-2 to identify the special affinity of f-WCNT to ACE2 labeled alveolar type II cells and the inhibition capacity to SARS-CoV-2. This design, is different from the so called “light vaccine”, has the real function to against SARS-CoV-2 by local cellular temperature-rising through photothermal conversion under the near infrared (NIR) light irradiation, according to the physical and chemical nature of carbon nanotubes, and initiates the immune response consequently.
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Affiliation(s)
- Jianshe Yang
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, 200072, People's Republic of China.
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79
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Wang CC, Prather KA, Sznitman J, Jimenez JL, Lakdawala SS, Tufekci Z, Marr LC. Airborne transmission of respiratory viruses. Science 2021; 373:eabd9149. [PMID: 34446582 PMCID: PMC8721651 DOI: 10.1126/science.abd9149] [Citation(s) in RCA: 536] [Impact Index Per Article: 178.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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80
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Wang CC, Prather KA, Sznitman J, Jimenez JL, Lakdawala SS, Tufekci Z, Marr LC. Airborne transmission of respiratory viruses. Science 2021. [PMID: 34446582 DOI: 10.1126/science:abd9149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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81
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Towards Promising Platform by Using Annular Photonic Crystals to Simulate and Design Useful Mask. PHOTONICS 2021. [DOI: 10.3390/photonics8090349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human masks are considered the mainstay in air filtration and purification technologies and against the spreading of bacterial and viral infections. This paper introduces a novel design of a human mask to increase the ultraviolet germicidal irradiation effect on pathogens. The proposed design consists of a tube with an annular photonic crystal (APC) attached to the mask’s orifice, and a UV source is located in the tube’s center. The main role of this study is the enhancement of UV doses based on the reflectivity of the proposed APC. Therefore, increasing pathogens’ inactivation level in the incoming air to the mask’s orifice could be investigated. The numerical investigations demonstrated that the proposed APC could provide a complete photonic bandgap with a high reflectivity in the wavelength regime from 207 to 230 nm. In addition, we have considered the roles of the thickness of layers, inner core radius, and the azimuthal number. Meanwhile, the results showed the ability to use a wide range of core radius values without almost any variations in the optical properties of the proposed design. Such results could grant the advantage of using this design by the manufacturing of human masks with different sizes besides the inclusions in other ultraviolet germicidal irradiation applications.
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82
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Sodiq A, Khan MA, Naas M, Amhamed A. Addressing COVID-19 contagion through the HVAC systems by reviewing indoor airborne nature of infectious microbes: Will an innovative air recirculation concept provide a practical solution? ENVIRONMENTAL RESEARCH 2021; 199:111329. [PMID: 34004171 PMCID: PMC8123526 DOI: 10.1016/j.envres.2021.111329] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 03/22/2021] [Accepted: 05/11/2021] [Indexed: 05/03/2023]
Abstract
As the world continues to grapple with the reality of coronavirus disease, global research communities are racing to develop practical solutions to adjust to the new challenges. One such challenge is the control of indoor air quality in the COVID-19 era and beyond. Since COVID-19 became a global pandemic, the "super spread" of the virus has continued to amaze policymakers despite measures put in place by public health officials to sensitize the general public on the need for social distancing, personal hygiene, etc. In this work, we have reviewed the literature to demonstrate, by investigating the historical and present circumstances, that indoor spread of infectious diseases may be assisted by the conditions of the HVAC systems. While little consideration has been given to the possibility of indoor airborne transmission of the virus, the available reports have demonstrated that the virus, with average aerodynamic diameter up to 80-120 nm, is viable as aerosol in indoor atmosphere for more than 3 h, and its spread may be assisted by the HVAC systems. Having reviewed the vulnerability of the conventional ventilation systems, we recommend innovative air circulation concept supported by the use of UVGI in combination with nanoporous air filter to combat the spread of SARS-CoV-2 and other harmful microbes in enclosed spaces.
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Affiliation(s)
- Ahmed Sodiq
- Qatar Environment and Energy Institute (QEERI), Qatar.
| | | | - Mahmoud Naas
- Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
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83
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Nicastro F, Sironi G, Antonello E, Bianco A, Biasin M, Brucato JR, Ermolli I, Pareschi G, Salvati M, Tozzi P, Trabattoni D, Clerici M. Solar UV-B/A radiation is highly effective in inactivating SARS-CoV-2. Sci Rep 2021; 11:14805. [PMID: 34285313 PMCID: PMC8292397 DOI: 10.1038/s41598-021-94417-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
Solar UV-C photons do not reach Earth's surface, but are known to be endowed with germicidal properties that are also effective on viruses. The effect of softer UV-B and UV-A photons, which copiously reach the Earth's surface, on viruses are instead little studied, particularly on single-stranded RNA viruses. Here we combine our measurements of the action spectrum of Covid-19 in response to UV light, Solar irradiation measurements on Earth during the SARS-CoV-2 pandemics, worldwide recorded Covid-19 mortality data and our "Solar-Pump" diffusive model of epidemics to show that (a) UV-B/A photons have a powerful virucidal effect on the single-stranded RNA virus Covid-19 and that (b) the Solar radiation that reaches temperate regions of the Earth at noon during summers, is sufficient to inactivate 63% of virions in open-space concentrations (1.5 × 103 TCID50/mL, higher than typical aerosol) in less than 2 min. We conclude that the characteristic seasonality imprint displayed world-wide by the SARS-Cov-2 mortality time-series throughout the diffusion of the outbreak (with temperate regions showing clear seasonal trends and equatorial regions suffering, on average, a systematically lower mortality), might have been efficiently set by the different intensity of UV-B/A Solar radiation hitting different Earth's locations at different times of the year. Our results suggest that Solar UV-B/A play an important role in planning strategies of confinement of the epidemics, which should be worked out and set up during spring/summer months and fully implemented during low-solar-irradiation periods.
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Affiliation(s)
- Fabrizio Nicastro
- Italian National Institute for Astrophysics (INAF)-Rome Astronomical Observatory, Rome, Italy.
| | - Giorgia Sironi
- Italian National Institute for Astrophysics (INAF)-Brera Astronomical Observatory, Merate, Milan, Italy
| | - Elio Antonello
- Italian National Institute for Astrophysics (INAF)-Brera Astronomical Observatory, Merate, Milan, Italy
| | - Andrea Bianco
- Italian National Institute for Astrophysics (INAF)-Brera Astronomical Observatory, Merate, Milan, Italy
| | - Mara Biasin
- Department of Biomedical and Clinical Sciences L. Sacco, University of Milano, Milan, Italy
| | - John R Brucato
- Italian National Institute for Astrophysics (INAF)-Arcetri Astrophysical Observatory, Florence, Italy
| | - Ilaria Ermolli
- Italian National Institute for Astrophysics (INAF)-Rome Astronomical Observatory, Rome, Italy
| | - Giovanni Pareschi
- Italian National Institute for Astrophysics (INAF)-Brera Astronomical Observatory, Merate, Milan, Italy
| | - Marta Salvati
- Regional Agency for Environmental Protection of Lombardia (ARPA Lombardia), Milan, Italy
| | - Paolo Tozzi
- Italian National Institute for Astrophysics (INAF)-Arcetri Astrophysical Observatory, Florence, Italy
| | - Daria Trabattoni
- Department of Biomedical and Clinical Sciences L. Sacco, University of Milano, Milan, Italy
| | - Mario Clerici
- Department of Pathophysiology and Transplantation, University of Milano, Don C. Gnocchi Foundation, IRCCS, Milan, Italy
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84
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A Tn-seq Screen of Streptococcus pneumoniae Uncovers DNA Repair as the Major Pathway for Desiccation Tolerance and Transmission. Infect Immun 2021; 89:e0071320. [PMID: 34031124 DOI: 10.1128/iai.00713-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that is a common cause of serious invasive diseases such as pneumonia, bacteremia, meningitis, and otitis media. Transmission of this bacterium has classically been thought to occur through inhalation of respiratory droplets and direct contact with nasal secretions. However, the demonstration that S. pneumoniae is desiccation tolerant and, therefore, environmentally stable for extended periods of time opens up the possibility that this pathogen is also transmitted via contaminated surfaces (fomites). To better understand the molecular mechanisms that enable S. pneumoniae to survive periods of desiccation, we performed a high-throughput transposon sequencing (Tn-seq) screen in search of genetic determinants of desiccation tolerance. We identified 42 genes whose disruption reduced desiccation tolerance and 45 genes that enhanced desiccation tolerance. The nucleotide excision repair pathway was the most enriched category in our Tn-seq results, and we found that additional DNA repair pathways are required for desiccation tolerance, demonstrating the importance of maintaining genome integrity after desiccation. Deletion of the nucleotide excision repair gene uvrA resulted in a delay in transmission between infant mice, indicating a correlation between desiccation tolerance and pneumococcal transmssion. Understanding the molecular mechanisms that enable pneumococcal persistence in the environment may enable targeting of these pathways to prevent fomite transmission, thereby preventing the establishment of new colonization and any resulting invasive disease.
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85
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Saddique A, Adnan S, Bokhari H, Azam A, Rana MS, Khan MM, Hanif M, Sharif S. Prevalence and Associated Risk Factor of COVID-19 and Impacts of Meteorological and Social Variables on Its Propagation in Punjab, Pakistan. EARTH SYSTEMS AND ENVIRONMENT 2021; 5:785-798. [PMID: 34723081 PMCID: PMC8260326 DOI: 10.1007/s41748-021-00218-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/10/2021] [Indexed: 06/13/2023]
Abstract
The current study identifies the spatial distribution of COVID-19 cases and its association with meteorological and social variables in Punjab (densely populated province of Pakistan). To identify the COVID-19 propagation, the weekly growth, recovery, and deaths rate have also been calculated. The geographic information system (GIS) has used to determine COVID-19 impacts on gender (male/female), age groups, and causalities over an affected population (km-2) for the period of 11th March to 12th August, 2020 in each district of province. Our results show that 43 peak days (where daily positive cases were above 900) have been observed in Punjab during 27th May to 8th July, 2020. The high population density districts, i.e., Lahore and Islamabad, have been affected (five persons per square kilometers) due to COVID-19, whereas the maximum death tolls (> 50 persons per millions) have also been observed in these urban districts. The meteorological variables (temperature, humidity, heat index, and ultraviolet index) show negative significant relationship to basic reproduction number (R0), whereas daily COVID-19 cases are positively correlated to aerosols concentration at 95% confidence level. The government intervention (stringency index) shows a positive impact to reduce the COVID-19 cases over the province. Keeping in view the COVID-19 behavior and climatology of the region, it has been identified that the COVID-19 cases may likely to increase during the dry period (high concentration of aerosols) i.e., October-December, 2020 and post-spring season (April to June), 2021 in urban areas of Pakistan. This study provides an overview on districts vulnerability that would help the policy makers, health agencies to plan their activities to reduce the COVID-19 impacts.
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Affiliation(s)
- Arbab Saddique
- COMSATS University Islamabad/Kohsar University, Islamabad/Murree, Pakistan
| | - Shahzada Adnan
- Pakistan Meteorological Department, Sector H-8/2, Islamabad, Pakistan
| | - Habib Bokhari
- COMSATS University Islamabad/Kohsar University, Islamabad/Murree, Pakistan
| | - Asima Azam
- Shaheed Benazir Bhutto Women University, Peshawar, Pakistan
| | | | | | - Muhammad Hanif
- Pakistan Meteorological Department, Sector H-8/2, Islamabad, Pakistan
| | - Shawana Sharif
- Shaheed Benazir Bhutto Hospital, Rawalpindi Medical University, Rawalpindi, Pakistan
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86
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Eadie E, O'Mahoney P, Finlayson L, Barnard IRM, Ibbotson SH, Wood K. Computer Modeling Indicates Dramatically Less DNA Damage from Far-UVC Krypton Chloride Lamps (222 nm) than from Sunlight Exposure. Photochem Photobiol 2021; 97:1150-1154. [PMID: 34161614 DOI: 10.1111/php.13477] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/11/2021] [Accepted: 06/21/2021] [Indexed: 01/06/2023]
Abstract
This study aims to investigate, with computer modeling, the DNA damage (assessed by cyclobutane pyrimidine dimer (CPD) formation) from far-ultraviolet C (far-UVC) in comparison with sunlight exposure in both a temperate (Harwell, England) and Mediterranean (Thessaloniki, Greece) climate. The research utilizes the published results from Barnard et al. [Barnard, I.R.M (2020) Photodermatol. Photoimmunol. Photomed. 36, 476-477] to determine the relative CPD yield of unfiltered and filtered far-UVC and sunlight exposure. Under current American Conference of Governmental Industrial Hygienists (ACGIH) exposure limits, 10 min of sunlight at an ultraviolet (UV) Index of 4-typical throughout the day in a temperate climate from Spring to Autumn-produces equivalent numbers of CPD as 700 h of unfiltered far-UVC or more than 30 000 h of filtered far-UVC at the basal layer. At the top of the epidermis, these values are reduced to 30 and 300 h, respectively. In terms of DNA damage induction, as assessed by CPD formation, the risk from sunlight exposure greatly exceeds the risk from far-UVC. However, the photochemistry that will occur in the stratum corneum from absorption of the vast majority of the high-energy far-UVC photons is unknown, as are the consequences.
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Affiliation(s)
- Ewan Eadie
- NHS Tayside, Photobiology Unit, Ninewells Hospital and Medical School, Dundee, UK
| | - Paul O'Mahoney
- Photobiology Unit, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Louise Finlayson
- School of Physics and Astronomy, SUPA, University of St Andrews, St Andrews, UK
| | | | - Sally Helen Ibbotson
- Photobiology Unit, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Kenneth Wood
- School of Physics and Astronomy, SUPA, University of St Andrews, St Andrews, UK
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87
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Corrêa TQ, Blanco KC, Vollet-Filho JD, Morais VS, Trevelin WR, Pratavieira S, Bagnato VS. Efficiency of an air circulation decontamination device for micro-organisms using ultraviolet radiation. J Hosp Infect 2021; 115:32-43. [PMID: 34126104 DOI: 10.1016/j.jhin.2021.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND The concern with environmental security to avoid contamination of individuals was intensified with the crisis established by SARS-CoV-2. The COVID-19 pandemic has shown the necessity to create systems and devices capable of clearing the air in an environment of micro-organisms more efficiently. The development of systems that allow the removal of micro-droplets mainly originating from breathing or talking from the air was the motivation of this study. AIM This article describes a portable and easy-to-operate system that helps to eliminate the droplets or aerosols present in the environment by circulating air through an ultraviolet-C (UV-C) reactor. METHODS An air circulation device was developed, and a proof-of-principle study was performed using the device against bacteria in simulated and natural environments. The microbiological analysis was carried out by the simple sedimentation technique. In order to compare the experimental results and the expected results for other micro-organisms, the reduction rate values for bacteria and viruses were calculated and compared with the experimental results based on technical parameters (clean air delivery rate (CADR) and air changes per hour (ACH)). FINDINGS Results showed that the micro-organisms were eliminated with high efficiency by the air circulation decontamination device, with reductions of 99.9% in the proof-of-principle study, and 84-97% in the hospital environments study, contributing to reducing contamination of individuals in environments considered to present risk. CONCLUSION This study resulted in a low-cost and relatively simple device, which was shown to be effective and safe, and could be replicated, especially in low-income countries, respecting the standards for air disinfection using UV-C technologies.
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Affiliation(s)
- T Q Corrêa
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil.
| | - K C Blanco
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - J D Vollet-Filho
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - V S Morais
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | | | - S Pratavieira
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - V S Bagnato
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil; Texas A&M University, College Station, TX, USA
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88
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Chiappa F, Frascella B, Vigezzi GP, Moro M, Diamanti L, Gentile L, Lago P, Clementi N, Signorelli C, Mancini N, Odone A. The efficacy of ultraviolet light-emitting technology against coronaviruses: a systematic review. J Hosp Infect 2021; 114:63-78. [PMID: 34029626 PMCID: PMC8139389 DOI: 10.1016/j.jhin.2021.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 12/13/2022]
Abstract
The ongoing pandemic of COVID-19 has underlined the importance of adopting effective infection prevention and control (IPC) measures in hospital and community settings. Ultraviolet (UV)-based technologies represent promising IPC tools: their effective application for sanitation has been extensively evaluated in the past but scant, heterogeneous and inconclusive evidence is available on their effect on SARS-CoV-2 transmission. With the aim of pooling the available evidence on the efficacy of UV technologies against coronaviruses, we conducted a systematic review following PRISMA guidelines, searching Medline, Embase and the Cochrane Library, and the main clinical trials' registries (WHO ICTRP, ClinicalTrials.gov, Cochrane and EU Clinical Trial Register). Quantitative data on studies' interventions were summarized in tables, pooled by different coronavirus species and strain, UV source, characteristics of UV light exposure and outcomes. Eighteen papers met our inclusion criteria, published between 1972 and 2020. Six focused on SARS-CoV-2, four on SARS-CoV-1, one on MERS-CoV, three on seasonal coronaviruses, and four on animal coronaviruses. All were experimental studies. Overall, despite wide heterogenicity within included studies, complete inactivation of coronaviruses on surfaces or aerosolized, including SARS-CoV-2, was reported to take a maximum exposure time of 15 min and to need a maximum distance from the UV emitter of up to 1 m. Advances in UV-based technologies in the field of sanitation and their proved high virucidal potential against SARS-CoV-2 support their use for IPC in hospital and community settings and their contribution towards ending the COVID-19 pandemic. National and international guidelines are to be updated and parameters and conditions of use need to be identified to ensure both efficacy and safety of UV technology application for effective infection prevention and control in both healthcare and non-healthcare settings.
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Affiliation(s)
- F Chiappa
- School of Public Health, University Vita-Salute San Raffaele, Milan, Italy
| | - B Frascella
- School of Public Health, University Vita-Salute San Raffaele, Milan, Italy
| | - G P Vigezzi
- School of Public Health, University Vita-Salute San Raffaele, Milan, Italy
| | - M Moro
- Infection Control Committee, IRCCS San Raffaele Hospital, Milan, Italy
| | - L Diamanti
- Clinical Engineering Unit, IRCCS San Raffaele Hospital, Milan, Italy; HTA Committee, IRCCS San Raffaele Hospital, Milan, Italy
| | - L Gentile
- Clinical Engineering Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - P Lago
- Clinical Engineering Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - N Clementi
- Laboratory of Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy
| | - C Signorelli
- School of Medicine, University Vita-Salute San Raffaele, Milan, Italy
| | - N Mancini
- Laboratory of Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy
| | - A Odone
- HTA Committee, IRCCS San Raffaele Hospital, Milan, Italy; Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
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89
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Li P, Koziel JA, Zimmerman JJ, Hoff SJ, Zhang J, Cheng TY, Yim-Im W, Lee M, Chen B, Jenks WS. Designing and Testing of a System for Aerosolization and Recovery of Viable Porcine Reproductive and Respiratory Syndrome Virus (PRRSV): Theoretical and Engineering Considerations. Front Bioeng Biotechnol 2021; 9:659609. [PMID: 34041230 PMCID: PMC8141751 DOI: 10.3389/fbioe.2021.659609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) infections cause significant economic losses to swine producers every year. Aerosols containing infectious PRRSV are an important route of transmission, and proper treatment of air could mitigate the airborne spread of the virus within and between barns. Previous bioaerosol studies focused on the microbiology of PRRSV aerosols; thus, the current study addressed the engineering aspects of virus aerosolization and collection. Specific objectives were to (1) build and test a virus aerosolization system, (2) achieve a uniform and repeatable aerosol generation and collection throughout all replicates, (3) identify and minimize sources of variation, and (4) verify that the collection system (impingers) performed similarly. The system for virus aerosolization was built and tested (Obj. 1). The uniform airflow distribution was confirmed using a physical tracer (<12% relative standard deviation) for all treatments and sound engineering control of flow rates (Obj. 2). Theoretical uncertainty analyses and mass balance calculations showed <3% loss of air mass flow rate between the inlet and outlet (Obj. 3). A comparison of TCID50 values among impinger fluids showed no statistical difference between any two of the three trials (p-value = 0.148, 0.357, 0.846) (Obj. 4). These results showed that the readiness of the system for research on virus aerosolization and treatment (e.g., by ultraviolet light), as well as its potential use for research on other types of airborne pathogens and their mitigation on a laboratory scale.
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Affiliation(s)
- Peiyang Li
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Jacek A Koziel
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Jeffrey J Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Steven J Hoff
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Ting-Yu Cheng
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Wannarat Yim-Im
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Myeongseong Lee
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Baitong Chen
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - William S Jenks
- Department of Chemistry, Iowa State University, Ames, IA, United States
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90
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Niazi S, Groth R, Spann K, Johnson GR. The role of respiratory droplet physicochemistry in limiting and promoting the airborne transmission of human coronaviruses: A critical review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 276:115767. [PMID: 33243541 PMCID: PMC7645283 DOI: 10.1016/j.envpol.2020.115767] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/16/2020] [Accepted: 09/29/2020] [Indexed: 05/19/2023]
Abstract
Whether virulent human pathogenic coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2) are effectively transmitted by aerosols remains contentious. Transmission modes of the novel coronavirus have become a hot topic of research with the importance of airborne transmission controversial due to the many factors that can influence virus transmission. Airborne transmission is an accepted potential route for the spread of some viral infections (measles, chickenpox); however, aerosol features and infectious inoculum vary from one respiratory virus to another. Infectious virus-laden aerosols can be produced by natural human respiratory activities, and their features are vital determinants for virus carriage and transmission. Physicochemical characteristics of infectious respiratory aerosols can influence the efficiency of virus transmission by droplets. This critical review identifies studies reporting instances of infected patients producing airborne human pathogenic coronaviruses, and evidence for the role of physical/chemical characteristics of human-generated droplets in altering embedded viruses' viability. We also review studies evaluating these viruses in the air, field studies and available evidence about seasonality patterns. Ultimately the literature suggests that a proportion of virulent human coronaviruses can plausibly be transmitted via the air, even though this might vary in different conditions. Evidence exists for respirable-sized airborne droplet nuclei containing viral RNA, although this does not necessarily imply that the virus is transmittable, capable of replicating in a recipient host, or that inoculum is sufficient to initiate infection. However, evidence suggests that coronaviruses can survive in simulated droplet nuclei for a significant time (>24 h). Nevertheless, laboratory nebulized virus-laden aerosols might not accurately model the complexity of human carrier aerosols in studying airborne viral transport. In summary, there is disagreement on whether wild coronaviruses can be transmitted via an airborne path and display seasonal patterns. Further studies are therefore required to provide supporting evidence for the role of airborne transmission and assumed mechanisms underlying seasonality.
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Affiliation(s)
- Sadegh Niazi
- Queensland University of Technology (QUT), Science and Engineering Faculty, School of Earth and Atmospheric Sciences, Brisbane, Australia
| | - Robert Groth
- Queensland University of Technology (QUT), Science and Engineering Faculty, School of Earth and Atmospheric Sciences, Brisbane, Australia
| | - Kirsten Spann
- Queensland University of Technology, Faculty of Health, School of Biomedical Sciences, Brisbane, Australia
| | - Graham R Johnson
- Queensland University of Technology (QUT), Science and Engineering Faculty, School of Earth and Atmospheric Sciences, Brisbane, Australia.
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91
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Boretti A, Banik B, Castelletto S. Use of Ultraviolet Blood Irradiation Against Viral Infections. Clin Rev Allergy Immunol 2021; 60:259-270. [PMID: 33026601 PMCID: PMC7538853 DOI: 10.1007/s12016-020-08811-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 01/14/2023]
Abstract
Ultraviolet blood irradiation (UBI) was used with success in the 1930s and 1940s for a variety of diseases. Despite the success, the lack of understanding of the detailed mechanisms of actions, and the achievements of antibiotics, phased off the use of UBI from the 1950s. The emergence of novel viral infections, from HIV/AIDS to Ebola, from SARS and MERS, and SARS-CoV-2, bring back the attention to this therapeutical opportunity. UBI has a complex virucidal activity, mostly acting on the immune system response. It has effects on lymphocytes (T-cells and B-cells), macrophages, monocytes, dendritic cells, low-density lipoprotein (LDL), and lipids. The Knott technique was applied for bacterial infections such as tuberculosis to viral infections such as hepatitis or influenza. The more complex extracorporeal photopheresis (ECP) is also being applied to hematological cancers such as T-cell lymphomas. Further studies of UBI may help to create a useful device that may find applications for novel viruses that are resistant to known antivirals or vaccines, or also bacteria that are resistant to known antibiotics.
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Affiliation(s)
- Alberto Boretti
- Prince Mohammad Bin Fahd University, 31952, Al-Khobar, Saudi Arabia.
| | - Bimal Banik
- Prince Mohammad Bin Fahd University, 31952, Al-Khobar, Saudi Arabia
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92
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Unal Y, Demirkilic U, Balik I, Aydin K, Zor MH, Bozkurt AK. Pilot Study of Application of Combined Transbronchial and Intravenous Ultraviolet C (UVC) and Laser Beam Application for the Treatment of Critical COVID-19 Infection. JOURNAL OF CLINICAL AND EXPERIMENTAL INVESTIGATIONS 2021. [DOI: 10.29333/jcei/10811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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93
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Bourdrel T, Annesi-Maesano I, Alahmad B, Maesano CN, Bind MA. The impact of outdoor air pollution on COVID-19: a review of evidence from in vitro, animal, and human studies. Eur Respir Rev 2021; 30:200242. [PMID: 33568525 PMCID: PMC7879496 DOI: 10.1183/16000617.0242-2020] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022] Open
Abstract
Studies have pointed out that air pollution may be a contributing factor to the coronavirus disease 2019 (COVID-19) pandemic. However, the specific links between air pollution and severe acute respiratory syndrome-coronavirus-2 infection remain unclear. Here we provide evidence from in vitro, animal and human studies from the existing literature. Epidemiological investigations have related various air pollutants to COVID-19 morbidity and mortality at the population level, however, those studies suffer from several limitations. Air pollution may be linked to an increase in COVID-19 severity and lethality through its impact on chronic diseases, such as cardiopulmonary diseases and diabetes. Experimental studies have shown that exposure to air pollution leads to a decreased immune response, thus facilitating viral penetration and replication. Viruses may persist in air through complex interactions with particles and gases depending on: 1) chemical composition; 2) electric charges of particles; and 3) meteorological conditions such as relative humidity, ultraviolet (UV) radiation and temperature. In addition, by reducing UV radiation, air pollutants may promote viral persistence in air and reduce vitamin D synthesis. Further epidemiological studies are needed to better estimate the impact of air pollution on COVID-19. In vitro and in vivo studies are also strongly needed, in particular to more precisely explore the particle-virus interaction in air.
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Affiliation(s)
- Thomas Bourdrel
- Memory Resource and Research Center, Geriatrics Dept, University Hospital of Strasbourg, Strasbourg, France
| | - Isabella Annesi-Maesano
- Sorbonne Université, INSERM, Pierre Louis Institute of Epidemiology and Public Health, Epidemiology of Allergic and Respiratory Diseases Dept (EPAR), Saint-Antoine Medical School, Paris, France
| | - Barrak Alahmad
- Dept of Environmental Health, Harvard T.H Chan School of Public Health, Boston, MA, USA
| | - Cara N Maesano
- Sorbonne Université, INSERM, Pierre Louis Institute of Epidemiology and Public Health, Epidemiology of Allergic and Respiratory Diseases Dept (EPAR), Saint-Antoine Medical School, Paris, France
| | - Marie-Abèle Bind
- Dept of Statistics, Faculty of Arts and Sciences, Harvard University, Cambridge, MA, USA
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94
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Bourdrel T, Annesi-Maesano I, Alahmad B, Maesano CN, Bind MA. The impact of outdoor air pollution on COVID-19: a review of evidence from in vitro, animal, and human studies. Eur Respir Rev 2021; 30:30/159/200242. [PMID: 33568525 DOI: 10.1183/16000617.0242-202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/11/2020] [Indexed: 05/24/2023] Open
Abstract
Studies have pointed out that air pollution may be a contributing factor to the coronavirus disease 2019 (COVID-19) pandemic. However, the specific links between air pollution and severe acute respiratory syndrome-coronavirus-2 infection remain unclear. Here we provide evidence from in vitro, animal and human studies from the existing literature. Epidemiological investigations have related various air pollutants to COVID-19 morbidity and mortality at the population level, however, those studies suffer from several limitations. Air pollution may be linked to an increase in COVID-19 severity and lethality through its impact on chronic diseases, such as cardiopulmonary diseases and diabetes. Experimental studies have shown that exposure to air pollution leads to a decreased immune response, thus facilitating viral penetration and replication. Viruses may persist in air through complex interactions with particles and gases depending on: 1) chemical composition; 2) electric charges of particles; and 3) meteorological conditions such as relative humidity, ultraviolet (UV) radiation and temperature. In addition, by reducing UV radiation, air pollutants may promote viral persistence in air and reduce vitamin D synthesis. Further epidemiological studies are needed to better estimate the impact of air pollution on COVID-19. In vitro and in vivo studies are also strongly needed, in particular to more precisely explore the particle-virus interaction in air.
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Affiliation(s)
- Thomas Bourdrel
- Memory Resource and Research Center, Geriatrics Dept, University Hospital of Strasbourg, Strasbourg, France
| | - Isabella Annesi-Maesano
- Sorbonne Université, INSERM, Pierre Louis Institute of Epidemiology and Public Health, Epidemiology of Allergic and Respiratory Diseases Dept (EPAR), Saint-Antoine Medical School, Paris, France
| | - Barrak Alahmad
- Dept of Environmental Health, Harvard T.H Chan School of Public Health, Boston, MA, USA
| | - Cara N Maesano
- Sorbonne Université, INSERM, Pierre Louis Institute of Epidemiology and Public Health, Epidemiology of Allergic and Respiratory Diseases Dept (EPAR), Saint-Antoine Medical School, Paris, France
| | - Marie-Abèle Bind
- Dept of Statistics, Faculty of Arts and Sciences, Harvard University, Cambridge, MA, USA
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95
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Prakash R, Digumarthi UK. An Emphasis on Engineering Controls and Administrative Controls in the Prevention and Control of COVID-19 in an Orthodontic Setting: Thinking Beyond Tomorrow. JOURNAL OF INDIAN ORTHODONTIC SOCIETY 2021. [DOI: 10.1177/0301574220988185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Introduction: Most of the initial focus in handling COVID-19 had been based on avoiding exposure by refraining from rendering most treatments other than those considered an emergency or urgent. Post-lockdown, with the resumption of most activities, there has been concern over the possibility of transmission scenarios if sufficient care is not taken. The control and prevention of the spread of infections when elimination of exposure is not possible is chiefly achieved through the judicious use of engineering controls and administrative controls in a clinical setting in addition to the standard protocols and transmission-based protocols. True safety lies in being one step ahead. There have been mentions of the possibility that COVID-19 could be opportunistic airborne in its spread, in addition to being spread via saliva, droplets, and contaminated surfaces or objects. Method: A literature search of PubMed, Google Scholar, Cochrane Library, and advisories released by such organizations as the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), Ministry of Health and Family Welfare (MOFHW), European Centre for Disease Prevention and Control (ECDC), Chinese Center for Disease Control and Prevention (China CDC), American Dental Association (ADA), Canadian Dental Association (CDA), French National Dentists Association, Dental Council of Belgium, National Health Service, England (NHS UK), National Health Service Scotland (NHS Scotland), and International Society for Infectious Diseases (ISID) was performed, with search parameters aimed at gathering information pertaining to infection control and cross infection control in dental settings as related to orthodontics. Result: There have been numerous articles and advisories published over the last 20 years, but the main focus has been on safe practices and to an extent on personal protective equipment, with relatively less emphasis on the need for respiratory protection by way of engineering controls and administrative controls. This review highlights the engineering and administrative controls that can be put into effect to make infection control and prevention much more effective. Conclusion: Any health care facility must be able to prevent, contain, and control infections with no risk of nosocomial infections. For this, an assumption has to be made that every individual in a health care setting is either at risk or a risk, depending on whether the person is infected or not. Meticulous attention to stringent policies of hygiene and infection control and prevention, coupled with suitable supporting engineering and administrative controls, is to be made a standard way of life in such facilities.
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Affiliation(s)
- R Prakash
- Department of Prosthdontics, Anil Neerukonda Institute of Dental Sciences, Visakhapatnam, Andhra Pradesh, India
| | - Uday K Digumarthi
- Department of Orthodontics, Anil Neerukonda Institute of Dental Sciences, Visakhapatnam, Andhra Pradesh, India
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Muñoz-Fernández J, Del Rosal Y, Álvarez-Gómez F, Hernández-Mariné M, Guzmán-Sepúlveda R, Korbee N, Figueroa FL. Selection of LED lighting systems for the reduction of the biodeterioration of speleothems induced by photosynthetic biofilms in the Nerja Cave (Malaga, Spain). JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 217:112155. [PMID: 33640830 DOI: 10.1016/j.jphotobiol.2021.112155] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 01/16/2021] [Accepted: 02/12/2021] [Indexed: 11/19/2022]
Abstract
Electrical lighting favours the development of photosynthetic biofilms in caves which can induce biodeterioration in the colonized substrates. The use of specific lights as a limiting factor for biofilm growth could be effective in their control and represents an alternative to chemical methods since they can damage the substrate. However, studies about lighting and the photosynthetic activity of organisms in caves are scarce. In order to select the most effective LED light source in reducing photosynthesis and therefore, in reducing the growth rates of microalgae and cyanobacteria, four biofilms in the Nerja Cave were illuminated by several light emitted diodes (LEDs) with different spectral compositions and the photobiological responses were measured both by empirical and theoretical methodologies. The empirical approach was based on the photosynthetic efficiency, by measuring the in vivo chlorophyll a (Chl a) fluorescence and the theoretical approach was based on the photonic assimilation performance related to the proportion of the light quality used for photosynthesis, according to the action spectra for photosynthesis available in the literature. The photobiological responses showed differences between the empirical and theoretical approach mainly in biofilms dominated by cyanobacteria and red algae, probably because the available action spectra were not useful for monitoring these Nerja Cave biofilms. However, the expected spectral responses of photosynthesis were observed in green microalgal biofilms with maximum photosynthetic efficiency in red and blue light although the green light was also unexpectedly high. The high photosynthetic efficiency in green light could be explained by the predictable high chlorophyll content due to a very dark environment. The results were not conclusive enough for all the biofilm types to be able to recommend a specific lighting system for the photocontrol of biofilm expansion. Therefore, new action spectra for photosynthesis of the extremophile organisms of the Nerja Cave are required. This approach, based on theoretical and empirical methodologies, is a useful tool to obtain information to allow the design of the most adequate lighting systems to reduce photosynthetic activity and favour the conservation of the caves.
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Affiliation(s)
- J Muñoz-Fernández
- Malaga University, Institute of Biotechnology and Blue Development (IBYDA), Department of Ecology and Geology, Campus Universitario de Teatinos s/n, 29071 Málaga, Spain.
| | - Y Del Rosal
- Nerja Cave Foundation, Research Institute, Carretera de Maro s/n, 29787 Nerja, Málaga, Spain
| | - F Álvarez-Gómez
- Malaga University, Institute of Biotechnology and Blue Development (IBYDA), Department of Ecology and Geology, Campus Universitario de Teatinos s/n, 29071 Málaga, Spain
| | - M Hernández-Mariné
- Barcelona University, Department of Biology, Health and Environment, 08028 Barcelona, Spain
| | - R Guzmán-Sepúlveda
- Malaga University, Department of Graphic Expression, Design and Project, Campus Universitario de Teatinos s/n, 29071 Málaga, Spain
| | - N Korbee
- Malaga University, Institute of Biotechnology and Blue Development (IBYDA), Department of Ecology and Geology, Campus Universitario de Teatinos s/n, 29071 Málaga, Spain
| | - F L Figueroa
- Malaga University, Institute of Biotechnology and Blue Development (IBYDA), Department of Ecology and Geology, Campus Universitario de Teatinos s/n, 29071 Málaga, Spain
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97
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Kitagawa H, Nomura T, Nazmul T, Omori K, Shigemoto N, Sakaguchi T, Ohge H. Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination. Am J Infect Control 2021; 49:299-301. [PMID: 32896604 PMCID: PMC7473342 DOI: 10.1016/j.ajic.2020.08.022] [Citation(s) in RCA: 120] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 12/16/2022]
Abstract
Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has emerged as a serious threat to human health worldwide. Efficient disinfection of surfaces contaminated with SARS-CoV-2 may help prevent its spread. This study aimed to investigate the in vitro efficacy of 222-nm far-ultraviolet light (UVC) on the disinfection of SARS-CoV-2 surface contamination. Methods We investigated the titer of SARS-CoV-2 after UV irradiation (0.1 mW/cm2) at 222 nm for 10-300 seconds using the 50% tissue culture infectious dose (TCID50). In addition, we used quantitative reverse transcription polymerase chain reaction to quantify SARS-CoV-2 RNA under the same conditions. Results One and 3 mJ/cm2 of 222-nm UVC irradiation (0.1 mW/cm2 for 10 and 30 seconds) resulted in 88.5 and 99.7% reduction of viable SARS-CoV-2 based on the TCID50 assay, respectively. In contrast, the copy number of SARS-CoV-2 RNA did not change after UVC irradiation even after a 5-minute irradiation. Conclusions This study shows the efficacy of 222-nm UVC irradiation against SARS-CoV-2 contamination in an in vitro experiment. Further evaluation of the safety and efficacy of 222-nm UVC irradiation in reducing the contamination of real-world surfaces and the potential transmission of SARS-CoV-2 is needed.
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Affiliation(s)
- Hiroki Kitagawa
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan; Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Toshihito Nomura
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tanuza Nazmul
- Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Keitaro Omori
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
| | - Norifumi Shigemoto
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan; Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Translational Research Center, Hiroshima University, Hiroshima, Japan
| | - Takemasa Sakaguchi
- Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiroki Ohge
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan; Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
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Bono N, Ponti F, Punta C, Candiani G. Effect of UV Irradiation and TiO 2-Photocatalysis on Airborne Bacteria and Viruses: An Overview. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1075. [PMID: 33669103 PMCID: PMC7956276 DOI: 10.3390/ma14051075] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/07/2021] [Accepted: 02/19/2021] [Indexed: 12/20/2022]
Abstract
Current COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has put a spotlight on the spread of infectious diseases brought on by pathogenic airborne bacteria and viruses. In parallel with a relentless search for therapeutics and vaccines, considerable effort is being expended to develop ever more powerful technologies to restricting the spread of airborne microorganisms in indoor spaces through the minimization of health- and environment-related risks. In this context, UV-based and photocatalytic oxidation (PCO)-based technologies (i.e., the combined action of ultraviolet (UV) light and photocatalytic materials such as titanium dioxide (TiO2)) represent the most widely utilized approaches at present because they are cost-effective and ecofriendly. The virucidal and bactericidal effect relies on the synergy between the inherent ability of UV light to directly inactivate viral particles and bacteria through nucleic acid and protein damages, and the production of oxidative radicals generated through the irradiation of the TiO2 surface. In this literature survey, we draw attention to the most effective UV radiations and TiO2-based PCO technologies available and their underlying mechanisms of action on both bacteria and viral particles. Since the fine tuning of different parameters, namely the UV wavelength, the photocatalyst composition, and the UV dose (viz, the product of UV light intensity and the irradiation time), is required for the inactivation of microorganisms, we wrap up this review coming up with the most effective combination of them. Now more than ever, UV- and TiO2-based disinfection technologies may represent a valuable tool to mitigate the spread of airborne pathogens.
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Affiliation(s)
- Nina Bono
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
| | - Federica Ponti
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair I in Biomaterials and Bioengineering for the Innovation in Surgery, Department Min-Met-Materials Engineering, Research Center of CHU de Quebec, Division of Regenerative Medicine, Laval University, Quebec City, QC G1V 0A6, Canada
| | - Carlo Punta
- OSCMLab, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy;
- Milano Politecnico Research Unit, National Interuniversity Consortium of Materials Science and Technology—INSTM, Via Mancinelli 7, 20131 Milan, Italy
| | - Gabriele Candiani
- GenT LΛB & µBioMI LΛB, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Via L. Mancinelli, 7, 20131 Milan, Italy; (N.B.); (F.P.)
- Milano Politecnico Research Unit, National Interuniversity Consortium of Materials Science and Technology—INSTM, Via Mancinelli 7, 20131 Milan, Italy
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99
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Komiyama M. Molecular-level Anatomy of SARS-CoV-2 for the Battle against COVID-19 Pandemic. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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100
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Bergman RS. Germicidal UV Sources and Systems †. Photochem Photobiol 2021; 97:466-470. [PMID: 33497482 PMCID: PMC8013001 DOI: 10.1111/php.13387] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/17/2021] [Indexed: 01/27/2023]
Abstract
The COVID‐19 pandemic has generated great interest in reviving an old intervention technology, particularly for air disinfection—ultraviolet germicidal irradiation (UVGI). Since UVGI was developed and refined more than 80–90 years ago, the ultraviolet source of choice has been almost exclusively the low‐pressure mercury vapor discharge lamp. Today, with new lamp technologies, there has been significant interest in the application of ultraviolet light‐emitting diodes and excimer lamps that emit in the UV‐C (180–280 nm) spectral band. This paper reviews these competing technologies with the aim of giving a sound basis for decisions on how to choose and install UV systems for disinfection of air and surfaces given the COVID‐19 pandemic.
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