UV Rate Constants

Kowalski, Władysław

doi:10.1007/978-3-642-01999-9_4

Cited by 11 publications

(8 citation statements)

References 241 publications

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“…The shoulder of the approximated curves drawn through the data was expected due to the length of time it takes for the initial damage of the radiation (due to internal repair mechanisms of the spores on germination). The shape of the SF curve is assumed to follow equation ( 1), the Multi-Hit model, where F is the radiative fluence and n and k are fitted values representing the recovery factor (related to the number of DNA radiation damage sites) and a first order decay rate, respectively 6 .…”

Section: Discussionmentioning

confidence: 99%

Degradation of aerosolized bacterial spores from ultraviolet radiation

Hart

Scotto

Eversole

2023

Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XXIV

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The most accurate insight to how aerosolized material responds to UV radiation is obtained by performing experiments on freely suspended particles, absent from the shadowing that deposition on a surface may impose. For this purpose we have developed a linear electrodynamic particle trap to confine suspended particles using a contact-free technique. The trap allows us to challenge and study aerosols under controlled environmental parameters such as temperature, humidity and radiation exposure. We present the results of a quantitative study on the changes in viability of Bacillus anthracis Sterne strain spores confined within this trap and illuminated by either simulated sunlight or a UV light source at 253.7 nm. Up to 500 same-size particles, (that is, consisting of approximately the same number of spores), were created from a dropleton-demand injector, trapped and irradiated with varying time scales. Illumination times ranged from 5 to 300 seconds with a maximum fluence of 500 J/m2 using the UV source, and particle clusters containing as little as 1 up to as many as 55 spores were used. As will be discussed, the viability of spores decreased as total fluence increased as expected, and for the same fluence, viability improved as the number of spores in each particle increased.

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Section: Discussionmentioning

confidence: 99%

Degradation of aerosolized bacterial spores from ultraviolet radiation

Hart

Scotto

Eversole

2023

Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XXIV

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“…Experimental tests have shown that UVC radiation is effective in 10 min to reduce SARS-CoV-2 viral load to undetectable level, moreover the UVC light can be efficiently implemented in the UV-SAN system for the sanitation of ambulance compartments where it was validated against MDR bacteria. Due to the precautions required by the Biosafety Level (BSL-3) for testing a pathogen, such as SARS-CoV-2, it is a standard technique to use surrogate species as a reference to higher BSL species, including bacteria [ 49 , 50 ]. Thus, it could be assume that the efficacy results obtained on the ambulance with MDR bacteria, could be extrapolated to the SARS-CoV-2.…”

Section: Discussionmentioning

confidence: 99%

UltraViolet SANitizing System for Sterilization of Ambulances Fleets and for Real-Time Monitoring of Their Sterilization Level

Michelini

Mazzei

Magurano

et al. 2021

IJERPH

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Background: The contamination of ambulances with pathogenic agents represents a potential threat for the public health, not only for common pathogens but also for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this project was to exploits the germicidal effect of the UVC radiation at 254 nm to sanitize the patient’s compartment of ambulances with an advanced UltraViolet SANitizing System (UV-SAN) and assess its relevance for avoiding the spread of COVID-19 and other drug resistant pathogens. Methods: The system is equipped with UVC lamps that are activated when the ambulance compartment is empty and sanitize the environment in less than 15 min. An Ozone sensor continuously monitors the gas concentration, ensuring it does not exceed threshold value harmful for patients and operators’ health. The system is relying on GNSS data and a satellite communication link, which allow to monitor and record traceability (when, where and what) of all the sanitation operations performed. This information is real-time monitored from a dedicated web-application. Results: UVC irradiation efficiently reduced SARS-CoV-2 virus titer (>99.99%), on inanimate surfaces such as plastic, stainless steel or rubber, with doses ranging from 5.5 to 24.8 mJ/cm2 and the UV-SAN system is effective against multi drug resistant (MDR) bacteria up to >99.99%, after 10 to 30 min of irradiation. Conclusions: UV-SAN can provide rapid, efficient and sustainable sanitization procedures of ambulances.

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“…The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsestengg.3c00019. SARS-CoV-2/Delta, SARS-CoV-2/Omicron, Delta/ Omicron, SARS-CoV-2/OC43, T-test, and significant virus SAR-CoV-2/SB2 (XLSX) 28 0.17 Mycobacterium tuberculosis 28 0.48 Influenza A virus 28 1.02 Phi6 Virus 25 0.03 T1UV bacteriophage 24 0.48 average of 96 tested viruses 28 0.58…”

Section: * Sı Supporting Informationmentioning

confidence: 99%

Exploring the Differences in the Response of SARS-CoV-2 Delta and Omicron to Ultraviolet Radiation

et al. 2023

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One method that can help slow the spread of coronaviruses is disinfection with UV light. The Delta and Omicron variants of the COVID-19 virus (SARS-CoV-2) have come to dominate the later stages of the pandemic due to their higher rates of transmission. In this work, it is shown that a 17% higher UV 254 dose is required for the disinfection of Delta and Omicron variants when compared to the ancestral strain of SARS-CoV-2. The UV 254 disinfection rate constants for SARS-CoV-2 and the Delta and Omicron variants were found to be 1.4 ± 0.3, 1.1 ± 0.2, and 1.1 ± 0.2 cm 2 /mJ, respectively. The rate constants of Delta and Omicron were statistically different from the ancestral strain of SARS-CoV-2 at the 95% confidence level based on at least three replicate experiments. It is suggested that the reason for this difference is the absence of repeating uracil (U) bases in the genome of the two variants. The UV 254 sensitivity of repeating pyrimidine bases is well-established. There are 2.6 and 3.7% fewer uracil triplets (UUU) in the Delta and Omicron variants, respectively, when compared to SARS-CoV-2. This difference in UV 254 sensitivity is relevant to a range of UV disinfection applications including upper-room disinfection, air handling equipment, aircraft sanitization, and others.

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UV Rate Constants

Cited by 11 publications

References 241 publications

Degradation of aerosolized bacterial spores from ultraviolet radiation

Degradation of aerosolized bacterial spores from ultraviolet radiation

UltraViolet SANitizing System for Sterilization of Ambulances Fleets and for Real-Time Monitoring of Their Sterilization Level

Exploring the Differences in the Response of SARS-CoV-2 Delta and Omicron to Ultraviolet Radiation

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