scholarly journals Degradation of OLED performance by exposure to UV irradiation

RSC Advances ◽  
2019 ◽  
Vol 9 (72) ◽  
pp. 42561-42568 ◽  
Author(s):  
Sun-Kap Kwon ◽  
Ji-Ho Baek ◽  
Hyun-Chul Choi ◽  
Seong Keun Kim ◽  
Raju Lampande ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Cathode Unit ◽  
Oled Performance

This paper reports the influence of UV radiation on the interface of a co-deposited EIL and Ag : Mg (10 : 1) cathode unit and pixel shrinkage.

Molecular Transformations in DNA under the Influence of UV-radiation

2020 ◽  
Vol 04 ◽  
Author(s):  
Vigen G. Barkhudaryan ◽  
Gayane V. Ananyan ◽  
Nelli H. Karapetyan
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Absorption Spectroscopy ◽  
Calf Thymus Dna ◽  
Dilute Solutions ◽  
Concentrated Solutions ◽  
Buffer Solution ◽  
Low Concentration ◽  
Calf Thymus ◽  
Dna Solutions

Background: The processes of destruction and crosslinking of macromolecules occur simultaneously under the influence of ultraviolet (UV) radiation in synthetic polymers, dry DNA and their concentrated solutions. Objective: The effect of UV radiation on calf thymus DNA in dilute solutions subjected to UV- irradiation was studied in this work. Method: The calf thymus DNA was studied in dilute solutions using viscometry, absorption spectroscopy and electrophoresis. Results: It was shown, that at a low concentration of DNA in the buffer solution ([DNA] = 85 μg / ml) under the influence of UV radiation, the processes of destruction of macromolecules and an increase in their flexibility predominate, which is accompanied by a gradual decrease in the viscosity of their solution. In addition, due to the low concentration of the solution, intramolecular crosslinking of macromolecules predominates, which also reduces their size and, consequently, the viscosity of the solution. Conclusion: It was concluded, that in dilute DNA solutions, due to the predominance of the processes of intramolecular crosslinking of macromolecules over intermolecular, only constant processes of decreasing the sizes of DNA macromolecules occur. As a result, its solubility remains virtually unchanged during UV irradiation. The described comments are also excellently confirmed by the results of absorption spectroscopy and electrophoresis

scholarly journals Comparative Solid Phase Photocatalytic Degradation of Polythene Films with Doped and Undoped TiO2Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Wasim Asghar ◽  
Ishtiaq A. Qazi ◽  
Hassan Ilyas ◽  
Aftab Ahmad Khan ◽  
M. Ali Awan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Ftir Spectroscopy ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Weight Reduction ◽  
Solid Phase ◽  
Sem Analysis ◽  
Artificial Light ◽  
Metal Doping

Comparative photocatalytic degradation of polythene films was investigated with undoped and metal (Fe, Ag, and Fe/Ag mix) doped TiO2nanoparticles under three different conditions such as UV radiation, artificial light, and darkness. Prepared photocatalysts were characterized by XRD, SEM, and EDS techniques. Photocatalytic degradation of the polythene films was determined by monitoring their weight reduction, SEM analysis, and FTIR spectroscopy. Weight of PE films steadily decreased and led to maximum of 14.34% reduction under UV irradiation with Fe/Ag mix doped TiO2nanoparticles and maximum of 14.28% reduction under artificial light with Ag doped TiO2nanoparticles in 300 hrs. No weight reduction was observed under darkness. Results reveal that polythene-TiO2compositing with metal doping has the potential to degrade the polythene waste under irradiation without any pollution.

Molecular analysis of enhanced replication of UV-damaged simian virus 40 DNA in UV-treated mammalian cells

1988 ◽  
Vol 8 (6) ◽  
pp. 2428-2434
Author(s):  
J M Treger ◽  
J Hauser ◽  
K Dixon
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Viral Dna ◽  
Repair Capacity ◽  
Pyrimidine Dimers ◽  
Infected Cells ◽  
Replicative Intermediates ◽  
Kinetics Of

Irradiation of simian virus 40 (SV40)-infected cells with low fluences of UV light (20 to 60 J/m2, inducing one to three pyrimidine dimers per SV40 genome) causes a dramatic inhibition of viral DNA replication. However, treatment of cells with UV radiation (20 J/m2) before infection with SV40 virus enhances the replication of UV-damaged viral DNA. To investigate the mechanism of this enhancement of replication, we analyzed the kinetics of synthesis and interconversion of viral replicative intermediates synthesized after UV irradiation of SV40-infected cells that had been pretreated with UV radiation. This enhancement did not appear to be due to an expansion of the size of the pool of replicative intermediates after irradiation of pretreated infected cells; the kinetics of incorporation of labeled thymidine into replicative intermediates were very similar after irradiation of infected control and pretreated cells. The major products of replication of SV40 DNA after UV irradiation at the low UV fluences used here were form II molecules with single-stranded gaps (relaxed circular intermediates). There did not appear to be a change in the proportion of these molecules synthesized when cells were pretreated with UV radiation. Thus, it is unlikely that a substantial amount of DNA synthesis occurs past pyrimidine dimers without leaving gaps. This conclusion is supported by the observation that the proportion of newly synthesized SV40 form I molecules that contain pyrimidine dimers was not increased in pretreated cells. Pulse-chase experiments suggested that there is a more efficient conversion of replicative intermediates into form I molecules in pretreated cells. This could be due to more efficient gap filling in relaxed circular intermediate molecules or to the release of blocked replication forks. Alternatively, the enhanced replication observed here may be due to an increase in the excision repair capacity of the pretreated cells.

scholarly journals Sensitivity to UV radiation of small nuclear RNA synthesis in mammalian cells.

1983 ◽  
Vol 3 (12) ◽  
pp. 2151-2155 ◽  
Author(s):  
G L Eliceiri ◽  
J H Smith
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Mammalian Cells ◽  
Repair Process ◽  
Rrna Synthesis ◽  
Small Nuclear Rna ◽  
Pyrimidine Dimers ◽  
5.8S Rrna ◽  
Nuclear Rna ◽  
U5 Snrna

It was demonstrated previously that the synthesis of small nuclear RNA (snRNA) species U1 and U2 in human cells is very sensitive to UV radiation. In the present work, the UV sensitivity of U3, U4, and U5 snRNA synthesis is shown to be also high. The synthesis of U1, U2, U3, U4, and U5 snRNAs progressively decreased during the first 2 h after UV irradiation (this was not observed in polyadenylated RNA) and had not returned to normal rates 6 h after UV exposure. In contrast, the restoration of 5.8S rRNA synthesis began immediately after UV irradiation and was essentially complete 6 h later. A small fraction of U1 and U5 (and possibly U2 and U3) snRNA synthesis remained unaffected by high UV doses, when cell radiolabeling began 10 min after UV irradiation. The present data suggest that a factor other than the level of pyrimidine dimers in DNA (possibly, steps in the post-irradiation DNA repair process) plays an important role in the mechanism of UV-induced inhibition of U1-U5 snRNA synthesis.

scholarly journals Polarimetry as a tool to find and characterise habitable planets orbiting white dwarfs

2014 ◽  
Vol 10 (S305) ◽  
pp. 325-332 ◽  
Author(s):  
Luca Fossati ◽  
Stefano Bagnulo ◽  
Carole A. Haswell ◽  
Manish R. Patel ◽  
Richard Busuttil ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
White Dwarf ◽  
White Dwarfs ◽  
Terrestrial Planet ◽  
Habitable Zone ◽  
Habitable Planets ◽  
Earth Like Planets ◽  
M Dwarf

AbstractThere are several ways planets can survive the giant phase of the host star, hence one can consider the case of Earth-like planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU from the star would remain in the continuous habitable zone (CHZ) for about 8 Gyr. Polarisation due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 102 (104) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a powerful tool to detect close-in planets around white dwarfs. Multi-band polarimetry would also allow one to reveal the presence of a planet atmosphere, even providing a first characterisation. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue. Preliminary habitability study show also that photosynthetic processes can be sustained on Earth-like planets orbiting CWDs and that the DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, hence white dwarfs are compatible with the persistence of complex life from the perspective of UV irradiation.

scholarly journals Effects of UV Radiation on Photolyase and Implications with Regards to Photoreactivation following Low- and Medium-Pressure UV Disinfection

2007 ◽  
Vol 74 (1) ◽  
pp. 327-328 ◽  
Author(s):  
Jiangyong Hu ◽  
Puay Hoon Quek
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Flavin Adenine Dinucleotide ◽  
Low Pressure ◽  
Uv Disinfection ◽  
Medium Pressure ◽  
Uv Lamps

ABSTRACT Photolyase activity following exposure to low-pressure (LP) and medium-pressure (MP) UV lamps was evaluated. MP UV irradiation resulted in a greater reduction in photolyase activity than LP UV radiation. The results suggest that oxidation of the flavin adenine dinucleotide in photolyase may have caused the decrease in activity.

scholarly journals Changes of chemical reactions in soil during electric processing by means of UV-radiation

2021 ◽  
Vol 304 ◽  
pp. 01014
Author(s):  
Anvar Anarbaev ◽  
Obid Tursunov ◽  
Dilshod Kodirov ◽  
Zayniddin Sharipov ◽  
Farrukh Mukhtarov
Keyword(s):  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Chemical Reactions ◽  
Uv Irradiation ◽  
Redox Reactions ◽  
Chemical Potential ◽  
Optimum Parameters ◽  
Agricultural Plants ◽  
Experimental Researches

The technology of electro-processing by UV-radiation soil of agricultural plants is considered. The mechanism of the effect of UV irradiation to change by redox reactions a chemical potential of the soil is shown. As the result of experimental researches, optimum parameters for processing soils with ultraviolet radiation lamps for increasing the absorption of the most mobile manganese forms in plants are defined.

scholarly journals Comparison of Reactive Blue 203 Dye Removal Using Ultraviolet Irradiation, Ferrate (VI) Oxidation Process and MgO Nanoparticles

2018 ◽  
Vol 5 (2) ◽  
pp. 78-90 ◽  
Author(s):  
Amirreza Talaiekhozani ◽  
Nilofar Torkan ◽  
Fahad Banisharif ◽  
Zeinab Eskandari ◽  
Shahabaldin Rezania ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Ultraviolet Irradiation ◽  
Contact Time ◽  
Dye Removal ◽  
Oxidation Process ◽  
Batch Mode ◽  
Mgo Nanoparticles ◽  
Ph Values

This study investigated the effect of various parameters on the removal of Reactive Blue 203 dye from wastewater using ferrate(VI) oxidation process, ultraviolet radiation (UV) radiation and MgO nanoparticles under batch mode. Although several studies have been carried out on dye removal, there is no study on the removal of Reactive Blue 203 dye using ferrate(VI) oxidation process, UV radiation, and MgO nanoparticles. Therefore, the aim of this study is to investigate the effect of different factors including pH, temperature, contact time, the intensity of UV radiation and the concentration of MgO nanoparticles on Reactive Blue 203 dye removal using the above-mentioned methods. The results showed that the best pH values for dye removal using UV radiation, ferrate(VI), and MgO nanoparticles were 13, 1 and 13, respectively. The best temperature for Reactive Blue 203 dye removal using ferrate(VI) was 50°C. Hence, temperature variation had no significant effect on Reactive Blue 203 dye removal using UV irradiation and absorption by MgO nanoparticles. Based on the results, the best contact time was 15 minutes using UV radiation. The removal of Reactive Blue 203 dye using ferrate(VI) oxidation process was a quick reaction, and in a fraction of a second, the reactions were completed. The results showed that dye removal using MgO nanoparticles could be described by the Temkin isotherm. Therefore, the contact time was not considered as an effective parameter. In addition, the maximum dye removals were 95, 85 and 94% using UV irradiation, ferrate(VI) and MgO nanoparticles.

scholarly journals UV radiation-induced SUMOylation of DDB2 regulates nucleotide excision repair

2017 ◽  
Vol 38 (10) ◽  
pp. 976-985 ◽  
Author(s):  
Chunhua Han ◽  
Ran Zhao ◽  
John Kroger ◽  
Jinshan He ◽  
Gulzar Wani ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nucleotide Excision Repair ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Excision Repair ◽  
26S Proteasome ◽  
Cell Extracts ◽  
Nucleotide Excision

Abstract Subunit 2 of DNA damage-binding protein complex (DDB2) is an early sensor of nucleotide excision repair (NER) pathway for eliminating DNA damage induced by UV radiation (UVR) and cisplatin treatments of mammalian cells. DDB2 is modified by ubiquitin and poly(ADP-ribose) (PAR) in response to UVR, and these modifications play a crucial role in regulating NER. Here, using immuno-analysis of irradiated cell extracts, we have identified multiple post-irradiation modifications of DDB2 protein. Interestingly, although the DNA lesions induced by both UVR and cisplatin are corrected by NER, only the UV irradiation, but not the cisplatin treatment, induces any discernable DDB2 modifications. We, for the first time, show that the appearance of UVR-induced DDB2 modifications depend on the binding of DDB2 to the damaged chromatin and the participation of functionally active 26S proteasome. The in vitro and in vivo analysis revealed that SUMO-1 conjugations comprise a significant portion of these UVR-induced DDB2 modifications. Mapping of SUMO-modified sites demonstrated that UVR-induced SUMOylation occurs on Lys-309 residue of DDB2 protein. Mutation of Lys-309 to Arg-309 diminished the DDB2 SUMOylation observable both in vitro and in vivo. Moreover, K309R mutated DDB2 lost its function of recruiting XPC to the DNA damage sites, as well as the ability to repair cyclobutane pyrimidine dimers following cellular UV irradiation. Taken together, our results indicate that DDB2 is modified by SUMOylation upon UV irradiation, and this post-translational modification plays an important role in the initial recognition and processing of UVR-induced DNA damage occurring within the context of chromatin.

scholarly journals Changes in Hepatic Phospholipid Metabolism in Rats under UV Irradiation and Topically Treated with Cannabidiol

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1157
Author(s):  
Michał Biernacki ◽  
Anna Jastrząb ◽  
Elżbieta Skrzydlewska
Keyword(s):  
Oxidative Stress ◽  
Environmental Factors ◽  
Prostaglandin E2 ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Prostaglandin F2α ◽  
Phospholipid Metabolism ◽  
Leukotriene B4 ◽  
Uvb Radiation ◽  
Uva Radiation

The liver is a key metabolic organ that is particularly sensitive to environmental factors, including UV radiation. As UV radiation induces oxidative stress and inflammation, natural compounds are under investigation as one method to counteract these consequences. The aim of this study was to assess the effect of topical application of phytocannabinoid-cannabidiol (CBD) on the skin of nude rats chronically irradiated with UVA/UVB, paying particular attention to its impact on the liver antioxidants and phospholipid metabolism. The results of this study indicate that CBD reaches the rat liver where it is then metabolized into decarbonylated cannabidiol, 7-hydroxy-cannabidiol and cannabidiol-glucuronide. CBD increased the levels of GSH and vitamin A after UVB radiation. Moreover, CBD prevents the increase of 4-hydroxynonenal and 8-iso-prostaglandin-F2α levels in UVA-irradiated rats. As a consequence of reductions in phospholipase A2 and cyclooxygenases activity following UV irradiation, CBD upregulates the level of 2-arachidonoylglycerol and downregulates prostaglandin E2 and leukotriene B4. Finally, CBD enhances decreased level of 15-deoxy-Δ-12,14-prostaglandin J2 after UVB radiation and 15-hydroxyeicosatetraenoic acid after UVA radiation. These data show that CBD applied to the skin prevents ROS- and enzyme-dependent phospholipid metabolism in the liver of UV-irradiated rats, suggesting that it may be used as an internal organ protector.

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