scholarly journals Solar UV light regulates flavonoid metabolism in apple (Malus x domestica)

2018 ◽  
Vol 41 (3) ◽  
pp. 675-688 ◽  
Author(s):  
Rebecca A. Henry-Kirk ◽  
Blue Plunkett ◽  
Miriam Hall ◽  
Tony McGhie ◽  
Andrew C. Allan ◽  
...  
Keyword(s):  
Uv Light ◽  
Malus X Domestica ◽  
Flavonoid Metabolism ◽  
Solar Uv

scholarly journals Solar simulated ultraviolet radiation inactivates HCoV-NL63 and SARS-CoV-2 coronaviruses at environmentally relevant doses

2021 ◽  
Author(s):  
Georg T. Wondrak ◽  
Jana Jandova ◽  
Spencer J. Williams ◽  
Dominik Schenten
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Uv Light ◽  
Gene Expression Array ◽  
Array Analysis ◽  
Expression Array ◽  
Response Gene ◽  
Full Spectrum ◽  
Solar Uv ◽  
Stress Response Gene

The germicidal properties of short wavelength ultraviolet C (UVC) light are well established and used to inactivate many viruses and other microbes. However, much less is known about germicidal effects of terrestrial solar UV light, confined exclusively to wavelengths in the UVA and UVB regions. Here, we have explored the sensitivity of the human coronaviruses HCoV-NL63 and SARS-CoV-2 to solar-simulated full spectrum ultraviolet light (sUV) delivered at environmentally relevant doses. First, HCoV-NL63 coronavirus inactivation by sUV-exposure was confirmed employing (i) viral plaque assays, (ii) RT-qPCR detection of viral genome replication, and (iii) infection-induced stress response gene expression array analysis. Next, a detailed dose-response relationship of SARS-CoV-2 coronavirus inactivation by sUV was elucidated, suggesting a half maximal suppression of viral infectivity at low sUV doses. Likewise, extended sUV exposure of SARS-CoV-2 blocked cellular infection as revealed by plaque assay and stress response gene expression array analysis. Moreover, comparative (HCoV-NL63 versus SARS-CoV-2) single gene expression analysis by RT-qPCR confirmed that sUV exposure blocks coronavirus-induced redox, inflammatory, and proteotoxic stress responses. Based on our findings, we estimate that solar ground level full spectrum UV light impairs coronavirus infectivity at environmentally relevant doses. Given the urgency and global scale of the unfolding SARS-CoV-2 pandemic, these prototype data suggest feasibility of solar UV-induced viral inactivation, an observation deserving further molecular exploration in more relevant exposure models.

Solar ultraviolet radiation dependent decrease of particle light absorption and pigments in lake phytoplankton

1997 ◽  
Vol 54 (3) ◽  
pp. 697-704 ◽  
Author(s):  
H Maske ◽  
M Latasa
Keyword(s):  
Light Absorption ◽  
Uv Light ◽  
Spectral Component ◽  
Ultraviolet B ◽  
Cutoff Wavelength ◽  
Solar Ultraviolet Radiation ◽  
Solar Uv ◽  
Band Pass ◽  
Solar Ultraviolet

The ultraviolet (UV) spectral component of daylight on a clear day at mid-latitudes can significantly reduce phytoplankton pigments within a daylight period. Phytoplankton samples from Redberry Lake, Saskatchewan, dominated by cyanobacteria were incubated in quartz bottles under optical long band-pass filters (cutoff wavelength 420-305 nm) in daylight in June. After incubation, samples were filtered, and in vivo particle light absorption (380-700 nm) and pigment concentrations were measured. Solar ultraviolet-B irradiance (UV-B; 280-320 nm) was measured radiometrically. On sunny days the samples that were exposed to daylight UV light showed a relative decrease in particle absorption and pigment concentration after the incubation compared with samples exposed only to visible daylight. No such decrease was observed during an overcast day. The UV-B data did not show a clear relation with the degree of pigment reduction, suggesting that other environmental factors or the state of adaptation partially controlled the pigment decrease of phytoplankton under UV-B exposure. Neither specific spectral components of the absorption spectrum nor specific pigments were more easily degraded than others by solar UV light, although the ratio of zeaxanthin to chlorophyll a probably increased in cyanobacteria as a result of UV exposure.

scholarly journals Formation of Secondary Organic Aerosols by Germicidal Ultraviolet Light

Environments ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 17
Author(s):  
Eureka Choi ◽  
Zhongchao Tan ◽  
William Anderson
Keyword(s):  
Uv Light ◽  
Fine Particulate Matter ◽  
Particle Formation ◽  
Uv Exposure ◽  
Indoor Environments ◽  
Fine Particulate ◽  
Volatile Organic ◽  
Solar Uv ◽  
Commercial Environment ◽  
Number Of Particles

Ultraviolet (UV) light with a wavelength of 254 nm is known to be germicidal, and thus has been increasingly employed as a method of disinfection for indoor environments. Solar UV wavelengths (300 to 400 nm) are known to initiate the formation of secondary organic aerosol (SOA) particles from the photo-oxidation of volatile organic compounds (VOC) in the atmosphere, but germicidal wavelengths have not been extensively studied for indoor environments. In this work, toluene was exposed to 254 nm UV light in a laboratory photoreactor while varying the conditions of the air, the duration of UV exposure, and the duration of post-UV time. The number of particles formed in the fine particulate matter (PM2.5) size range was measured, and significant levels of particle formation were observed for UV exposure periods of as short as 5 min. The particle formation ranged from 2.4 × 106 particles/m3 for 5 min of UV exposure, to 163.2 × 106 particles/m3 for 15 min of UV exposure, for toluene concentrations in the range of 55 to 85 mg/m3. Particle formation was found to increase at a relative humidity of approximately 20% and higher. Variations in the initial number of particles present did not appear to have a significant effect on the particle formation, suggesting that nucleation was not a controlling factor under these conditions. However, tests in a commercial environment at much lower VOC concentrations and lower UV fluence rates showed no detectable PM2.5 formation, indicating that SOA formation during the intermittent use of germicidal UV may not significantly affect indoor air quality under normal conditions.

scholarly journals Solar UV-B/A radiation is highly effective in inactivating SARS-CoV-2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabrizio Nicastro ◽  
Giorgia Sironi ◽  
Elio Antonello ◽  
Andrea Bianco ◽  
Mara Biasin ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Open Space ◽  
Uv Light ◽  
Rna Virus ◽  
Action Spectrum ◽  
Solar Irradiation ◽  
Mortality Data ◽  
Solar Uv ◽  
Solar Pump ◽  
Set Up

AbstractSolar 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.

scholarly journals Formation of Secondary Organic Aerosols by Germicidal Ultraviolet Light

2018 ◽  
Author(s):  
Eureka Choi ◽  
Zhongchao Tan ◽  
William A. Anderson
Keyword(s):  
Uv Light ◽  
Fine Particulate Matter ◽  
Particle Formation ◽  
Uv Exposure ◽  
Indoor Environments ◽  
Fine Particulate ◽  
Volatile Organic ◽  
Solar Uv ◽  
Commercial Environment ◽  
Number Of Particles

Ultraviolet (UV) light with a wavelength of 254 nm has proven to be effective at inactivating microorganisms, and thus has been increasingly employed as a method of disinfection for indoor environments. Solar UV wavelengths (300 to 400 nm) are known to initiate the formation of secondary organic aerosol (SOA) particles from photo-oxidation of volatile organic compounds in the atmosphere, but germicidal wavelengths have not been extensively studied for indoor environments.  In this work, toluene was exposed to 254 nm UV light in a laboratory photoreactor, with varying conditions of the air, the duration of UV exposure, and the duration of post-UV time. The number of particles formed in the fine particulate matter (PM2.5) size range was measured, and significant levels of particle formation were observed for UV exposure periods of as short as 5 minutes. The particle formation ranged from 2.4x106 particles/m3 for 5 minutes of UV exposure, to 1449.8x106 particles/m3 for 15 minutes of UV exposure. Particle formation was found to increase with increasing concentrations of gas phase toluene, and at relative humidity of approximately 20% and higher. Variations in the initial number of particles present did not appear to have a significant effect on the particle formation, suggesting that nucleation was not a controlling factor. However, tests in a commercial environment showed no significant detectable PM2.5 formation, indicating that SOA formation during the intermittent use of germicidal UV may not significantly affect indoor air quality.

Optical Bleaching and Phototransfer of BeO TL Detector by Simulated Solar UV Light

1990 ◽  
Vol 33 (1-4) ◽  
pp. 201-202
Author(s):  
L. Lembo ◽  
M. Pimpinella ◽  
B. Mukherjee
Keyword(s):  
Uv Light ◽  
Solar Uv ◽  
Optical Bleaching

scholarly journals Mutagenic specificity of solar UV light in nucleotide excision repair-deficient rodent cells.

1996 ◽  
Vol 93 (1) ◽  
pp. 176-180 ◽  
Author(s):  
E. Sage ◽  
B. Lamolet ◽  
E. Brulay ◽  
E. Moustacchi ◽  
A. Chteauneuf ◽  
...  
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Uv Light ◽  
Nucleotide Excision ◽  
Solar Uv

scholarly journals Loss of inducible photorepair in a frog cell line hypersensitive to solar UV light

FEBS Letters ◽  
1987 ◽  
Vol 225 (1-2) ◽  
pp. 133-138 ◽  
Author(s):  
Chuck C.-K. Chao ◽  
Sue Lin-Chao
Keyword(s):  
Cell Line ◽  
Uv Light ◽  
Solar Uv
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