Effects Of Ultraviolet Radiation Research Articles

Efficiency improvement of Bactericides and Biostats Application when Using Seawater in a Reservoir Pressure Maintenance System

The article presents materials on the classification of groups of corrosion-hazardous bacteria developing at oilfield facilities, classification of oil fields by microbiological problems, critical points for the development of sulfate-reducing bacteria, as well as classification of methods to combat microbiological corrosion. The effect of UV irradiation on the inhibition of microorganisms is also described. The proposals of the Gubkin Institute on the joint application of biocides, biostats and UV irradiation to combat sulfate-reducing bacteria are given.

Challenges in scaling of IPVD deposited Ta barriers on OSG low‐k films: Carbonization of Ta by CHx radicals generated through VUV‐induced decomposition of carbon‐containing groups

AbstractThe effect of vacuum ultraviolet (VUV) radiation during ionized physical vapor deposition (IPVD) of tantalum barriers on various porous organosilicate glass low‐k SiCOH films is studied using advanced diagnostics and quantum chemical calculations. VUV photons break the Si–C bonds, releasing hydrocarbon radicals from the pore surfaces. These radicals, trapped in pores that are partially sealed by tantalum deposition, can either react with tantalum to form carbide‐like compounds, TaCx, or be redeposited in the pores as CHx polymers. This is evidenced by a decrease in CH3 groups that correlates with an increase in TaCx. The formation of TaCx poses a significant challenge in the back end of line (BEOL) technology when reducing the barrier thickness.

UV irradiation enhanced removal of colloidal phosphorus in agricultural runoff

Colloidal phosphorus (P) is an important P form in agricultural runoff and can threaten water quality. However, up to date, there are few effective approaches to mitigate colloidal P pollution. This study investigated the effect of ultraviolet (UV) irradiation on medium-colloidal (MC; 220 nm–450 nm) and fine-colloidal (FC; 3 kDa–220 nm) P in agricultural runoff. Under 24 h of UV irradiation, as the most abundant colloidal P fraction, concentration of total P (TP) in FC consistently decreased by 81.0%, while TP concentration in MC first increased by 74.4% after 3 h and then decreased with irradiation time. At the same time, particulate TP (>450 nm) concentration was found to be increased from 0 to 14.7 μM. However, there were no obvious variations in TP concentrations in FC and MC fractions under dark conditions. In FC fraction, with the decrease of TP, the corresponding concentrations of iron (Fe), aluminum (Al), silicon (Si) declined synchronously, and ferric iron/ferrous iron (Fe(III)/Fe(II)) ratio and organic matter (OM) concentration were reduced as well. These results suggested that P in FC fraction was gradually transformed into particulate P during photoreduction of Fe(III) and photodegradation of OM under UV irradiation. Our study helps to understand the mechanism of the phototransformation of colloidal P, and propose an UV irradiation-based approach to remove colloidal P in agricultural runoff.

Degradation of the cytostatic drug bicalutamide by photo-assisted catalytic wet peroxide oxidation

The presence of cytostatic drugs, such as bicalutamide (BICA), in aquatic compartments reveals the necessity of developing efficient processes for their elimination in wastewater treatment plants (WWTP). This work explores for the first time the use of natural magnetite as a low-cost catalyst in the photo assisted — catalytic wet peroxide oxidation (UV-CWPO) of BICA. For this purpose, real WWTP secondary effluents were spiked with 100 μg/L BICA and subjected to UV-CWPO. Preliminary runs comparing UV photolysis, UV/H2O2, CWPO and UV-CWPO confirmed the synergistic effect of UV radiation and the CWPO process employing magnetite. Afterwards, a parametric study was performed evaluating the influence of the pH, catalyst load, H2O2 dosage, temperature and water matrix. Under optimum operating conditions (pH 0: 6, [magnetite]: 375 mg/L and [H2O2]: 75 mg/L), 99.7 % BICA degradation and 60.7 % mineralization were reached after 30 min in WWTP effluent. UV-CWPO also proved to be effective in hospital wastewater. Catalyst activity was studied in 5 consecutive runs, showing great stability for both BICA removal and TOC elimination. Finally, phytotoxicity tests revealed a lower toxicity in the UV-CWPO effluent compared to the untreated stream. Hence, UV-CWPO proved to be a feasible to eliminate risky cytostatic drugs in relevant environmental matrices.

Synergistic interplay of UV radiation and urban particulate matter induces impairment of autophagy and alters cellular fate in senescence-prone human dermal fibroblasts.

Skin aging is a complex process influenced by intrinsic factors and environmental stressors, including ultraviolet (UV) radiation and air pollution, among others. In this study, we investigated the effects of UVA and UVB radiation, combined with urban particulate matter (UPM), on human dermal fibroblasts (HDF). We show here that treatment of HDF with a subcytotoxic dose of UVA/UVB results in a series of events leading to mitochondrial dysfunction, increased ROS levels, and DNA damage. These effects are known to trigger either cellular senescence or cell death, depending on the cells' ability to clear damage by activating autophagy. Whereas UPM treatment in isolation did not affect proliferation or survival of HDF, of note, simultaneous UPM treatment of UV-irradiated cells selectively inhibited autophagic flux, thereby changing cell fate of a fraction of the cell population from senescence to apoptotic cell death. Our findings highlight the synergistic effects of UV radiation and UPM on skin aging, emphasizing the need to consider these factors in assessing the impact of environmental stressors on human health and opening opportunities for developing comprehensive approaches to protect and preserve skin integrity in the face of growing environmental challenges.

A Continuous-Wave EPR Investigation into the Photochemical Transformations of the Chromium(I) Carbonyl Complex [Cr(CO)4bis(diphenylphosphino)]+ and Reactivity with 1-hexene.

Chromium complexes containing a bis(diphenylphosphino) ligand have attracted significant interest over many years due to their potential as active catalysts for ethylene oligomerisation when combined with suitable co-catalysts such as triethylaluminium (TEA) or methylaluminoxane (MAO). While there has been considerable attention devoted to the possible reaction intermediates and the nature of the Cr oxidation states involved, the potential UV photoactivity of the Cr(I) complexes has so far been overlooked. Therefore, to explore the photoinduced transformations of bis(diphenylphosphino) stabilized Cr(I) complexes, we used continuous-wave (CW) EPR to study the effects of UV radiation on a cationic [Cr(CO)4(dppp)]+[Al(OC(CF3)3)4]- complex (1), where dppp represents the 1,3 bis-(diphenylphosphino)propane ligand, Ph2P(C3H6)PPh2. Our preliminary investigations into the photochemistry of this complex revealed that [Cr(CO)4(dppp)]+ (1) can be readily photo-converted into an intermediate mer-[Cr(CO)3(κ1-dppp)(κ2-dppp)]+ complex (2) and eventually into a trans-[Cr(CO)2(dppp)2]+ complex (3) in solution at room temperature under UV-A light. Here, we show that the intermediate species (2) involved in this transformation can be identified by EPR at much lower temperature (140 K) and at a specific wavelength (highlighting the wavelength dependency of the reaction). In addition, small amounts of a 'piano-stool'-type complex, namely [Cr(CO)2(dppp-η6-arene)]+ (4), can also be formed during the photoconversion of [Cr(CO)4(dppp)]+ using UV-A light. There was no evidence for the formation of the [Cr(L-bis-η6-arene)]+ complex (5) in these UV irradiation experiments. For the first time, we also evidence the formation of a 1-hexene coordinated [Cr(CO)3(dppp)(1-hexene)]+ complex (6) following UV irradiation of [Cr(CO)4(dppp)]+ in the presence of 1-hexene; this result demonstrates the unprecedented opportunity for exploiting light activation during Cr-driven olefin oligomerisation catalysis, instead of expensive, difficult-to-handle, and hazardous chemical activators.

Biomarkers of UVB radiation-related senescent fibroblasts

Excessive exposure to ultraviolet (UV) light is known to induce photoaging in the skin, necessitating the development of effective anti-photoaging strategies to mitigate the adverse effects of UV radiation. Understanding the biofunctional characteristics of diverse skin cell types and unraveling the molecular modifications implicated in the aging process are pivotal in comprehending the intricacies of photoaging in human skin. Such insights are essential for paving the way for innovative interventions to counteract the deleterious impact of UV radiation on the skin. The single-cell RNA sequencing data of UVB-irradiated and normal control mouse skin in GSE173385 were downloaded from the Gene Expression Omniniub (GEO) database. First, cell types were identified using Seurat for normalization, dimensionality reduction and clustering. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis were executed on these cell subpopulations. Using FindAllMarkers in the Seurat package to identify differential gene expression and Monocle2 cell trajectory analysis, we screened out hub genes related to the development trajectory of senescent fibroblasts during photoaging, and then combined it with 307 aging-related genes collected in the HAGR library, we finally identified two biomarkers. The efficiency of biomarkers in diagnosing UV radiation photoaging was also evaluated in the dataset. Concurrently, the immune infiltration of identified biomarkers under UV radiation has also been further explored. Moreover, we employed the Enrichr platform to conduct a comprehensive screening of drug molecules associated with the identified biomarkers. Our comprehensive analysis, employing Seurat for normalization, dimensionality reduction, and clustering, successfully identified ten distinct cell types within the samples. Then GO functional enrichment analysis showed that senescent fibroblasts are mainly involved in the regulation of immune effector processes such as cytokine-mediated signaling pathways, regulation of epithelial cell proliferation and intercellular adhesion. Afterwards, KEGG analysis determined the main biological pathways are: IL-17 signaling pathway, Cytokine–cytokine receptor interaction, Metabolism of xenobiotics by cytochrome P450. After differential gene expression and Monocle2 cell trajectory analysis, we matched the obtained hub genes with the aging-related genes collected in the HAGR library, and finally screened out two relevant biomarkers: Apoe and Gdf15 which are related to the development trajectory of senescent fibroblasts during photoaging. Meanwhile, the immune infiltration further implied that the expression of these two biomarkers was significantly correlated with immune cells. In addition, the Enrichr platform was used to screen the drug molecules related to these biomarkers. This strategic approach aimed to pinpoint effective molecular targets for the prevention and treatment of photoaging. Our investigation has effectively characterized biomarkers associated with fibroblast senescence during photoaging at the single-cell level, We have validated their correlation with cellular immune inflammation and identified potential drug targets through the utilization of the Enrichr platform. This foundational research establishes a robust basis for the development of therapeutic interventions targeting skin diseases resulting from photoaging.

Impacts of UV radiation on Bacillus biocontrol agents and their resistance mechanisms.

Bacillus biocontrol agent(s) BCA(s) such as Bacillus cereus, Bacillus thuringiensis and Bacillus subtilis have been widely applied to control insects' pests of plants and pathogenic microbes, improve plant growth, and facilitate their resistance to environmental stresses. In the last decade, researchers have shown that, the application of Bacillus biocontrol agent(s) BCA(s) optimized agricultural production yield, and reduced disease risks in some crops. However, these bacteria encountered various abiotic stresses, among which ultraviolet (UV) radiation severely decrease their efficiency. Researchers have identified several strategies by which Bacillus biocontrol agents resist the negative effects of UV radiation, including transcriptional response, UV mutagenesis, biochemical and artificial means (addition of protective agents). These strategies are governed by distinct pathways, triggered by UV radiation. Herein, the impact of UV radiation on Bacillus biocontrol agent(s) BCA(s) and their mechanisms of resistance were discussed.

Methylxanthine and Flavonoid Contents from Guarana Seeds (Paullinia cupana): Comparison of Different Drying Techniques and Effects of UV Radiation.

Guarana seeds are typically processed using one of three drying methods: traditional sun exposure, greenhouse drying, or the alguidar oven technique. In our research, we evaluated the contents of methylxanthines and flavan-3-ols in sun- and alguidar-dried guarana seeds from Bahia State's Low Sul Identity Territory. Caffeine, theobromine, catechin, and epicatechin were determined by high-performance liquid chromatography with UV-visible detection (HPLC/UV-vis). Statistical tools, including analysis of variance (ANOVA), Tukey's test, and exploratory analysis, were employed to analyze the obtained data. Our findings indicated that the flavan-3-ols content in sun-dried guarana samples was lower compared to those dried using the alguidar oven, possibly due to exposure to ultraviolet radiation from solar energy. Conversely, we observed no significant differences (p > 0.05) in the average contents of methylxanthines between the two drying methods. Our supplementary experiments involving UV-A and UV-C radiation lamps revealed a decreasing trend in methylxanthines and flavan-3-ols contents with increasing duration of UV radiation exposure.

Effects of ultraviolet irradiation on quality and bacterial diversity of fresh-cut cabbage during storage

Effects of ultraviolet irradiation on quality and bacterial diversity of fresh-cut cabbage during storage

Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

PVA/CdS-Ag Nanocomposites: Effect of Composition and UV Radiation on Optical, Electrical and Structural Properties

PVA incorporated with different content of CdS-Ag nanostructures are prepared using chemical reduction technique. Along with this these nanocomposites are exposed to UV radiated for different times. The X-ray spectraof PVA /CdS-Ag nanocomposites indicatethe formation of CdS and Ag nanostructures within PVA.Changes in the band structure of nanocomposites with and without UV exposure are studied by UV-Visible spectroscopy. Absorbance and refractive index are noticed to show increment with the concentration of nanostructures and time of exposure. Along with this, the behaviour of different optical parameters such as E0 and Ed is investigated. FE-SEM and EDX analysis exhibit microstructural modification occurring in nanocomposites due to changes in the concentration of incorporated nanostructures and UV radiation. Influence of concentration and UV exposure on conductivity and dielectric parameters on PVA/CdS-Ag nanocomposites are studied.

A Comprehensive Study on Formulation of Herbal Sunscreen Using Aloe barbadensis, Cucumis sativus and Solanum lycopersicum

Sunscreen formulations play a crucial role in protecting the skin from the harmful effects of ultraviolet (UV) radiation. Recent advancements in nature and herbal ingredients have led to a surge of interest in formulation effective, eco-friendly sunscreens. This review provides a comprehensive analysis of herbal sunscreen formulations, specially focusing on Aloe barbadensis miller (Aloe vera), Cucumis sativus (Cucumber), and Solanum lycopersicum (Tomato) as key ingredients. Aloe vera, known for its soothing and hydrating properties, offers potential benefits enhancing the skin’s resilience against UV damage. Cucumis sativus contributes cooling and antioxidant effects, while Solanum lycopersicum provides substantial levels of lycopene, which is recognized for its photoprotective qualities. The review systematically examines the phytochemical profiles, extraction methods, and efficacy of these ingredients in sunscreen formulations. It also explores their synergistic effects when combined and evaluates their overall performance in terms of sun protection factor (SPF), stability, and skin compatibility. By synthesizing current research findings, this review aims to highlight the potential of these herbal components in developing effective, natural sunscreens and to provide insights for future research and formulation strategies in the field of dermatological protection.

Melanin: Nature's 4th bioorganic polymer.

The pigments known as the melanins are widely recognized for their responsibility in the coloration of human skin, eyes, hair, and minimising the harmful effects of solar ultraviolet radiation. But specialists are aware that the melanins are present in all living kingdoms, barring viruses, and have functionality that extends beyond neutralizing ionising radiation. The ubiquitous presence of melanin in almost all human organs, recognized in recent years, as well as the presence of melanin in organisms that are evolutionarily distant from each other, indicate the fundamental importance of this class of material for all life forms. In this review, we argue for the need to accept melanins as the fourth primordial class of biological polymers, along with nucleic acids, proteins and polysaccharides. We consistently compare the properties of these canonical biological polymers with the properties of melanin and highlight key features that fundamentally distinguish melanins, their function and its mysteries.

Impact of blue light on cutaneous barrier structures and properties: NPLC/HR-MSn and Raman analyses.

Skin health relies heavily on a well-maintained cutaneous barrier. While the detrimental effects of UV radiation on the epidermis are established, the impact of blue light, a significant component of sunlight and artificial sources, is less clear. This study aims to explore blue light's influence on the reconstructed human epidermis (RHE) using two complementary analytical approaches: Raman microspectroscopy and normal phase liquid chromatography coupled with high-resolution mass spectrometry (NPLC/HR-MSn). RHE samples were exposed to blue light (415 nm and 455 nm) during different stages of their maturation. Raman spectra were acquired for both irradiated and non-irradiated (control) samples. Raman descriptors were analyzed to assess potential alterations in the structural organization of proteins and lipids' conformational changes. Additionally, lipids from RHE samples were extracted and analyzed using NPLC/HR-MSn. Blue light exposure led to changes in the structural organization of RHE lipids and proteins, as well as changes in the lipid composition. These changes varied depending on the wavelength and exposure dose. Exposure to blue light could disrupt the integrity of the skin's protective barrier, leading to increased sensitivity to environmental stressors and potential skin damage.

Comparative assessment of UV-C radiation and non-thermal plasma for inactivation of foodborne fungal spores suspension in vitro.

Fungal contamination poses a persistent challenge to industries, particularly in food, healthcare, and clinical sectors, due to the remarkable resilience of fungi in withstanding conventional control methods. In this context, our research delves into the comparative efficacy of UV radiation and non-thermal plasma (NTP) on key foodborne fungal contaminants - Alternaria alternata, Aspergillus niger, Fusarium culmorum, and Fusarium graminearum. The study examined the impact of varying doses of UV radiation on the asexual spores of all mentioned fungal strains. Simultaneously, the study compared the effects of UV radiation and NTP on the metabolic activity of cells after spore germination and their subsequent germination ability. The results revealed that UV-C radiation (254 nm) did not significantly suppress the metabolic activity of cells after spore germination. In contrast, NTP exhibited almost 100% effectiveness on both selected spores and their subsequent germination, except for A. niger. In the case of A. niger, the effectiveness of UV-C and NTP was nearly comparable, showing only a 35% decrease in metabolic activity after 48 hours of germination, while the other strains (A. alternata, F. culmorum, F. graminearum) exhibited a reduction of more than 95%. SEM images illustrate the morphological changes in structure of all tested spores after both treatments. This study addresses a crucial gap in existing literature, offering insights into the adaptation possibilities of treated cells and emphasizing the importance of considering exposure duration and nutrient conditions (introduction of fresh medium). The results highlighted the promising antimicrobial potential of NTP, especially for filamentous fungi, paving the way for enhanced sanitation processes with diverse applications.

Study of the effect of ultraviolet radiation on the development of corona discharge in high voltage networks

Study of the effect of ultraviolet radiation on the development of corona discharge in high voltage networks

Evaluation the Effect of Ultraviolet Radiation on Fiber Fragment Release from Textiles

Evaluation the Effect of Ultraviolet Radiation on Fiber Fragment Release from Textiles

Mutagenic effects of ultraviolet radiation and trimethyl psoralen in mycoplasma toward a minimal genome.

Mycoplasmas, autonomously culturable bacteria with the smallest genome, are an important organism to understand the minimal form of life. Mutagenesis using mutagens is a useful methodology for understanding the essential regions of genomic information. Ultraviolet light (UV) and trimethyl psoralen (TMP) are mutagens known to induce various mutations; the latter is reported to specifically induce deletions in nematodes. However, their mutagenic effects on mycoplasma are not known. Here, we exposed Metamycoplasma salivarium to UV-C light or TMP and UV-A as mutagens, and analyzed the mutational pattern after serial cultivation ranging from 34 to 56 rounds for different lineages. Our results showed that more deletions, but fewer point mutations, were induced with TMP and UV-A than with UV-C, indicating the usefulness of TMP in inducing deletions. In addition, we compared our results with mutational data from other studies, which suggested that the combination of TMP and UV-A or UV-C exposure both induced point mutations that were highly biased toward C→T and G→A transitions. These data provide useful basic knowledge for mutational studies on M. salivarium.

Mechanisms of photoisomerization of the prenylated flavin mononucleotide cofactor: a theoretical study.

The enzymatic decarboxylation of α,β-unsaturated acids using the ferulic acid decarboxylase (Fdc1) enzyme and prenylated flavin mononucleotide (prFMN) cofactor is a potential, environmentally friendly reaction for the biosynthesis of styrene and its derivatives. However, experiments showed that the enzyme activity of Fdc1 depends on the ring structure of prFMN, namely, the iminium and ketimine forms, and the loss of enzyme activity results from prFMNim → prFMNket photoisomerization. To obtain insight into this photochemical process and to improve the enzyme efficiency of Fdc1, two proposed photoisomerization mechanisms with different proton sources for the acid-base reaction were studied herein using theoretical methods. The potential energy surfaces calculated using the density functional theory method with the Becke, 3-parameter, and Lee-Yang-Parr hybrid functionals and DZP basis set (DFT/B3LYP/DZP) and TD-DFT/B3LYP/DZP methods confirmed that the light-dependent reaction occurs in the rate-determining proton transfer process and that the mechanism involving intermolecular proton transfer between prFMNim and Glu282 (external base) is energetically more favorable than that involving intramolecular proton transfer in prFMNim (internal base). The thermodynamic results obtained from the transition state theory method suggested that the exothermic relaxation energy in the photo-to-thermal process can promote the spontaneous formation of a high-energy-barrier transition state, and an effective enzymatic decarboxylation could be achieved by slowing down the formation of the undesirable thermodynamically favorable product (prFMNket). Because the rate constant for formation of the high-energy-barrier transition state varies exponentially over the temperature range of 273-298 K, and experimental results have shown that incubating Fdc1 on ice results in a complete loss of enzyme activity, it is recommended to perform the decarboxylation reaction at 285 K to strike a balance between minimizing enzyme stability loss at 273 K and mitigating the effects of UV irradiation. The computational strategy and fundamental insights obtained in this study could serve as guidelines for future theoretical and experimental investigations on the same and similar photochemical systems.