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In the papermaking industry, cellulose fibers often undergo a bleaching process which affects the surface of the fibers, or their overall morphology. The surface of the produced paper, which is most often used as a printing substrate, depends on the production method, the arrangement of the cellulose fibers, and the quantity and fineness of the filler. The micro-irregularities caused by the uneven distribution of fibers and surface particles of the filler make the paper’s surface rough and affect the print quality and its stability when exposed to light from the moment of production to use. The unbleached cellulose fibers in the printing substrate contain natural pigments, lignin and hemicellulose that absorb UV radiation, as opposed to bleached fibers, which have higher whiteness and lightfastness. Therefore, the influence of UV radiation on the surface roughness of prints made on papers with natural unbleached and bleached hemp fibers was analyzed. This research confirmed that papers formed from unbleached fibers have rougher surface and that printed graphic products from bleached fibers have higher stability to UV radiation than those from natural, unbleached hemp fibers after 96 h of treatment in the Suntest chamber.

UV radiation (UVR) has significant physiological effects on organisms living at or near the Earth's surface, yet the full suite of genes required for fitness of a photosynthetic organism in a UVR-rich environment remains unknown. This study reports a genome-wide fitness assessment of the genes that affect UVR tolerance under environmentally relevant UVR dosages in the model cyanobacterium Synechococcus elongatus PCC 7942. Our results highlight the importance of specific genes that encode proteins involved in DNA repair, glutathione synthesis, and the assembly and maintenance of photosystem II, as well as genes that encode hypothetical proteins and others without an obvious connection to canonical methods of UVR tolerance. Disruption of a gene that encodes a leucyl aminopeptidase (LAP) conferred the greatest UVR-specific decrease in fitness. Enzymatic assays demonstrated a strong pH-dependent affinity of the LAP for the dipeptide cysteinyl-glycine, suggesting an involvement in glutathione catabolism as a function of night-time cytosolic pH level. A low differential expression of the LAP gene under acute UVR exposure suggests that its relative importance would be overlooked in transcript-dependent screens. Subsequent experiments revealed a similar UVR-sensitivity phenotype in LAP knockouts of other organisms, indicating conservation of the functional role of LAPs in UVR tolerance.

We have described the influence of selected factors that increase the toxicity of nanoplastics (NPs) and microplastics (MPs) with regard to cell viability, various types of cell death, reactive oxygen species (ROS) induction, and genotoxicity. These factors include plastic particle size (NPs/MPs), zeta potential, exposure time, concentration, functionalization, and the influence of environmental factors and cell type. Studies have unequivocally shown that smaller plastic particles are more cytotoxic, penetrate cells more easily, increase ROS formation, and induce oxidative damage to proteins, lipids, and DNA. The toxic effects also increase with concentration and incubation time. NPs with positive zeta potential are also more toxic than those with a negative zeta potential because the cells are negatively charged, inducing stronger interactions. The deleterious effects of NPs and MPs are increased by functionalization with anionic or carboxyl groups, due to greater interaction with cell membrane components. Cationic NPs/MPs are particularly toxic due to their greater cellular uptake and/or their effects on cells and lysosomal membranes. The effects of polystyrene (PS) vary from one cell type to another, and normal cells are more sensitive to NPs than cancerous ones. The toxicity of NPs/MPs can be enhanced by environmental factors, including UV radiation, as they cause the particles to shrink and change their shape, which is a particularly important consideration when working with environmentally-changed NPs/MPs. In summary, the cytotoxicity, oxidative properties, and genotoxicity of plastic particles depends on their concentration, duration of action, and cell type. Also, NPs/MPs with a smaller diameter and positive zeta potential, and those exposed to UV and functionalized with amino groups, demonstrate higher toxicity than larger, non-functionalized and environmentally-unchanged particles with a negative zeta potential. [ABSTRACT FROM AUTHOR]

Astaxanthin (AST) is a xanthophyll carotenoid with strong oxidation resistance, which can effectively scavenge various free radicals and protect organisms from oxidative damage. AST is also known to have prominent anti‐aging effects, but the underlying mechanism of AST in anti‐radiation aging is largely unknown. In this work, we applied ultraviolet (UV) irradiation to accelerate the aging of Caenorhabditis elegans (C. elegans) and treated the nematodes with AST to explore whether and how AST could attenuate the radiation‐induced aging effect. Our results showed that AST improved the survival rate of C. elegans, reduced the aging biomarkers, and alleviated the mitochondrial dysfunction caused by the irradiation. Based on the transcriptome sequencing analysis, we identified that the key genes regulated by AST were involved in JNK‐MAPK and DAF‐16 longevity signaling pathways. Furthermore, we employed jnk‐1 and daf‐16 mutants and verified the role of the JNK‐1/DAF‐16 signaling pathway in the anti‐aging effect. As such, this study has not only demonstrated that AST can resist the aging process caused by UV‐irradiation but also revealed the anti‐aging mechanism of AST through JNK‐1/DAF‐16 activation in C. elegans. [ABSTRACT FROM AUTHOR]

Introduction. Germicidal lamps have a wavelength range of 200-280 nm and can affect the integrity of the DNA of people who handle this equipment. Human lymphocytes are excellent biomonitors of genetic damage and widely used with the comet assay. Objective. Evaluation of genotoxicity in human blood cells exposed to UV-C radiation (254 nm) emitted by germicidal lamps and the cytoprotective effect of ascorbic acid, using the comet test. Material and methods. Slides containing lymphocytes immersed in agarose gel were exposed to UV-C radiation (254 nm) for periods of 5, 10 and 15 minutes and 70 cm away. The antigenotoxic effect was determined in cells exposed to UV-C for 5 minutes and 70 cm away, subsequently the slides were subjected to an ascorbic acid solution for periods of 5, 10 and 15 mM for two hours. In both situations, genetic damage was quantified by the comet test using three parameters: tail length, tail moment, and migration groups. Results. The three parameters detected significant genotoxic activity (p<0.05) in the times of exposure to UV-C and cytoprotective effect of ascorbic acid (p<0.05). Conclusions. The handling of UV-C germicidal lamps is often wrong and dangerous to exposed people or organisms. These data suggest that ascorbic acid increases DNA protection in cells exposed to UV-C radiation. [ABSTRACT FROM AUTHOR]

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In our study, we investigated the accelerated aging process of PLA under 253.7 nm UV-C irradiation with the use of the GPC, NMR, FTIR, and DSC methods and formal kinetic analysis. The results of GPC and DSC indicated a significant degree of destructive changes in the PLA macromolecules, while spectroscopic methods NMR and FTIR showed maintenance of the PLA main structural elements even after a long time of UV exposure. In addition to that, the GPC method displayed the formation of a high molecular weight fraction starting from 24 h of irradiation, and an increase in its content after 144 h of irradiation. It has been shown for the first time that a distinctive feature of prolonged UV exposure is the occurrence of intra- and intermolecular radical recombination reactions, leading to the formation of a high molecular weight fraction of PLA decomposition products. This causes the observed slowdown of the photolysis process. It was concluded that photolysis of PLA is a complex physicochemical process, the mechanism of which depends on morphological changes in the solid phase of the polymer under UV radiation. [ABSTRACT FROM AUTHOR]

Cyanobacteria inhabit extreme environments, including drylands, providing multiple benefits to the ecosystem. Soil degradation in warm drylands is increasing due to land use intensification. Restoration methods adapted to the extreme stress in drylands are being developed, such as cyanobacteria inoculation to recover biocrusts. For this type of restoration method to be a success, it is crucial to optimize the survival of inoculated cyanobacteria in the field. One strategy is to harden them to be acclimated to stressful conditions after laboratory culturing. Here, we analyzed the genome and ecophysiological response to osmotic desiccation and UVR stresses of an Antarctic cyanobacterium, Stenomitos frigidus ULC029, which is closely related to other cyanobacteria from warm and cold dryland soils. Chlorophyll a concentrations showed that preculturing ULC029 under moderate osmotic stress improved its survival during an assay of desiccation plus rehydration under UVR. Additionally, its sequential exposure to these stress factors increased the production of exopolysaccharides, carotenoids, and scytonemin. Desiccation, but not osmotic stress, increased the concentrations of the osmoprotectants trehalose and sucrose. However, osmotic stress might induce the production of other osmoprotectants, for which the complete pathways were observed in the ULC029 genome. In total, 140 genes known to be involved in stress resistance were annotated. Here, we confirm that the sequential application of moderate osmotic stress and dehydration could improve cyanobacterial hardening for soil restoration by inducing several resistance mechanisms. We provide a high‐quality genome of ULC029 and a description of the main resistance mechanisms (i.e., production of exopolysaccharides, osmoprotectants, chlorophyll, and carotenoids; DNA repair; and oxidative stress protection). [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) radiation, a component of sunlight, holds both advantageous anddetrimental effects on human health. While shorter wavelengths of UV radiationaid in melanin and vitamin D synthesis, longer wavelengths pose risks like skincancer and premature aging due to DNA damage. To combat such stress, cellsemploy various mechanisms, including the heat shock response (HSR). Activation of this response involves a highly regulated transcriptional processorchestrated by heat shock factors (HSFs). While HSF1 has been observed as a keytranscription factor for HSR, other HSFs are also found to be associated withdiverse cellular functions, including stress responses. Here, we discuss arecent study by Feng et al., published in Clinical and Translational Medicine, shedding light on the novel function of HSF4 in regulating inflammation and senescence following UV exposure. The researchers observed acomplex of HSF4 and the cofactor COIL (Coilin) at R‐loops–aberrant DNA‐RNAhybrid structures arising from UV‐induced DNA damage in human skin cells. Inthe study, they proposed the HSF4‐COIL complex at R‐loops as a potential therapeutic target to mitigate UV‐induced skin damage. [ABSTRACT FROM AUTHOR]

Stratospheric ozone, which has been depleted in recent decades by the release of anthropogenic gases, is critical for shielding the biosphere against ultraviolet‐B (UV‐B) radiation. Although the ozone layer is expected to recover before the end of the 21st century, a hole over Antarctica continues to appear each year. Ozone depletion usually peaks between September and October, when fortunately, most Antarctic terrestrial vegetation and soil biota is frozen, dormant and protected under snow cover. Similarly, much marine life is protected by sea ice cover. The ozone hole used to close before the onset of Antarctic summer, meaning that most biota were not exposed to severe springtime UV‐B fluxes. However, in recent years, ozone depletion has persisted into December, which marks the beginning of austral summer. Early summertime ozone depletion is concerning: high incident UV‐B radiation coincident with snowmelt and emergence of vegetation will mean biota is more exposed. The start of summer is also peak breeding season for many animals, thus extreme UV‐B exposure (UV index up to 14) may come at a vulnerable time in their life cycle. Climate change, including changing wind patterns and strength, and particularly declining sea ice, are likely to compound UV‐B exposure of Antarctic organisms, through earlier ice and snowmelt, heatwaves and droughts. Antarctic field research conducted decades ago tended to study UV impacts in isolation and more research that considers multiple climate impacts, and the true magnitude and timing of current UV increases is needed. [ABSTRACT FROM AUTHOR]

Nonmetallic ionic liquids (ILs) exhibit unique advantages in catalyzing poly (ethylene terephthalate) (PET) glycolysis, but usually require longer reaction times. We found that exposure to UV radiation can accelerate the glycolysis reaction and significantly reduce the reaction time. In this work, we synthesized five nonmetallic dibasic ILs, and their glycolysis catalytic activity was investigated. 1,8-diazabicyclo [5,4,0] undec-7-ene imidazole ([HDBU]Im) exhibited better catalytic performance. Meanwhile, UV radiation is used as a reinforcement method to improve the PET glycolysis efficiency. Under optimal conditions (5 g PET, 20 g ethylene glycol (EG), 0.25 g [HDBU]Im, 10,000 µW·cm−2 UV radiation reacted for 90 min at 185 °C), the PET conversion and BHET yield were 100% and 88.9%, respectively. Based on the UV-visible spectrum, it was found that UV radiation can activate the C=O in PET. Hence, the incorporation of UV radiation can considerably diminish the activation energy of the reaction, shortening the reaction time of PET degradation. Finally, a possible reaction mechanism of [HDBU]Im-catalyzed PET glycolysis under UV radiation was proposed. [ABSTRACT FROM AUTHOR]

Wastewater treatment to remove organic ecotoxicants is one the most important problems today. Scientists' efforts throughout the world are focused on searching for effective and harmless technologies for the removal and/or complete degradation of organic pollutants. One of the solutions is the use of UV lamps in combination with various oxidants. UV irradiation is widely used in various branches of industry, especially in water treatment. Photolysis methods are environmentally clean and are included in handbooks of the best available technologies. Experiments performed in this study were aimed at revealing kinetic relationships of the photochemical degradation of dihydric phenols in aqueous solutions under the action of active species. All the processes were performed using a flow-through laboratory installation. A 9 W, 254 nm OSMAR special ozone-free bactericidal lamp (Finland) was chosen as a UV radiation source. The residence time of the model solution in the reactor was varied from 20 to 120 s. Quantitative determination of dihydric phenols was performed by the spectrophotometric method. Hydrogen peroxide (3% solution) and potassium persulfate were chosen as oxidizing additives. The potential of the UV radiation and oxidative treatment for efficient removal of dihydric phenols from water was evaluated. Photooxidation of pyrocatechol, resorcinol, and hydroquinone in aqueous solution in the presence of hydrogen peroxide and potassium persulfate was performed. The oxidants were taken in amount from stoichiometric to fivefold excess relative to the stoichiometry. The photochemical degradation of dihydric phenols can be performed with up to 99% efficiency. At the phenol : oxidant molar ratio of 1 : 5, the photooxidation rate increases by a factor of 3–5. The degradation involves the breakdown of the benzene ring, and the main degradation products of dihydric phenols are monobasic carboxylic acids and formaldehyde. [ABSTRACT FROM AUTHOR]

Composites of polyether polylactide (PLA) synthesized from natural raw materials with graphite nanoplatelets (GNPs), which represent a new type of composite materials based on biodegradable polymers, are obtained by the solid-phase method under the action of shear deformations. The porosity of the composites is evaluated and their electrical and mechanical properties are studied. The effect of UV radiation on the molecular weight and molecular weight distribution of PLA in PLA–GNP composites of different composites is investigated using the method of exclusion chromatography, and the effect of GNP nanofiller content on the change of their mechanical characteristics in the process of radiation is shown. [ABSTRACT FROM AUTHOR]

In recent years, non-thermal plasma (NTP) has emerged as a promising tool for decontamination and disinfection within the food industry. Given the increasing resistance of microbial biofilms to conventional disinfectants and their adverse environmental effects, this method has significant potential for eliminating biofilm formation or mitigating the metabolic activity of grown biofilms. A comparative study was conducted evaluating the efficacy of UV radiation and NTP in eradicating mature biofilms of four common foodborne filamentous fungal contaminants: Alternaria alternata, Aspergillus niger, Fusarium culmorum, and Fusarium graminearum. The findings reveal that while UV radiation exhibits variable efficacy depending on the duration of exposure and fungal species, NTP induces substantial morphological alterations in biofilms, disrupting hyphae, and reducing extracellular polymeric substance production, particularly in A. alternata and F. culmorum. Notably, scanning electron microscopy analysis demonstrates significant disruption of the hyphae in NTP-treated biofilms, indicating its ability to penetrate the biofilm matrix, which is a promising outcome for biofilm eradication strategies. The use of NTP could offer a more environmentally friendly and potentially more effective alternative to traditional disinfection methods. [ABSTRACT FROM AUTHOR]

The introduction of the first list of priority pathogenic fungi by the World Health Organization stresses the need to research and develop public health actions to mitigate infections caused by fungi. One of those actions involves the water disinfection systems, which comprise classical and alternative methods that have been developed in the last decades. Thereby, this work reviews the disinfection of fungi by classical methods such as chlorination, ozonation, and ultraviolet (UV) treatments and alternative advanced oxidation processes (AOPs) such as photo-Fenton, photocatalysis, or couplings of UV with peroxides. The matrices of aquatic systems (sewage, groundwater, drinking water, among others) were considered. A bibliometric analysis is performed initially, and then some aspects of the resistance to antifungals are presented, and the efficiency of the diverse processes in the reduction in fungal loading is also revised. Herein, it is shown the role of the disinfecting agents (e.g., chlorine, hydroxyl radical, or light) and their effects on fungi structures (e.g., direct DNA damage, or indirect damage due to the action of radicals). Moreover, gaps, such as the treatment of antifungal-resistant fungi and limited information about combinations among AOPs, related to the disinfection of water polluted by fungi, were identified. [ABSTRACT FROM AUTHOR]

In this paper, simple fiber optic sensors for the detection of UV electromagnetic radiation are presented. These advantages are general advantages of OF not belonging only to FPI. A single-mode fiber with two different diameters, 122 µm, and 4 µm, is used. The end of the optical fiber was covered with a UV-sensitive material, Phosphor. Both sensor heads were irradiated by UV radiation. The reflected spectra were collected every 5 min. From the results, the reflected spectra were attenuated due to the interaction of the UV-sensitive layer with the applied radiation. In general, both sensors showed good sensitivity and high linearity. However, the average intensity sensitivity was higher for the sensors of smaller diameters. They were equal to (−) 0.0024 a.u/nm and (−) 0.0061 a.u./min for the sensor of 122 µm and 4 µm, respectively. This type of sensors have many applications like monitoring UV radiation in outdoor environment, measuring the UV index which is very important parameter that influence the people health, especially in hot weather regions. And many other important application in different fields. [ABSTRACT FROM AUTHOR]

In this paper, we describe conversion factors (CF) for the calculation of biologically effective irradiances (BEI) from erythemal irradiance for three effects: photosynthesis of previtamin D3, psoriasis healing, and inactivation of the SARS-Cov-2 virions. CFs were empirically derived from measurements of spectral solar ultraviolet (UV) radiation during all sky conditions at four mid-latitude sites in the Northern Hemisphere, namely Aosta, Belsk, Reading, and San Diego. These CFs were found to depend on solar zenith angle (SZA) and total column ozone, but are largely independent (within ± 5% for SZA < 60°) of local conditions such as surface albedo, visibility and other local atmospheric patterns. The values of these empirical CFs are consistent with analytical CFs derived with radiative transfer calculations (model FastRT) for clear-sky and overcast conditions. To validate these analytical CFs, one-hour radiant exposures for the three biological effects were calculated from erythemal measurements at Reading between 2012 and 2021 and compared with similar exposures calculated directly from the spectral UV measurements. The two datasets agreed within 10% for SZA < 65°, demonstrating the utility of the conversion method. These results suggest that the proposed analytical CFs can be used with confidence to estimate radiant exposures for the three biological effects from measurements of the UV Index at any northern mid-latitude site. [ABSTRACT FROM AUTHOR]

Astaxanthin (AX) is known as a very strong antioxidant and has been utilised in many kinds of products such as foods, pharmaceutical, cosmetics, aquaculture, etc. One of the natural resources of AX is Haematococcus pluvialis which has been investigated by some researchers in order to enhance the AX production. However, the production of AX from the microalgae is still costly, hence, this present research is proposing low-cost methods namely bean sprout media (BSM) as an alternative growth media and UV radiation. The variations of BSM concentrations (2, 4, and 6 %) and times of UV radiation (1.5 and 3 hrs) were treated to H. pluvialis in laboratory conditions. BSM 4 % treatment showed an optimum growth of the microalga at 427 x 104 cell/ml (day 8) which also exhibited macrozooid, palmella, and aplanosore phases. UV radiation for 3 hr revealed that the concentration of AX production was as much as 17.37±0.04 mg/l. The research results were potential to be developed further in order to discover better and cheaper methods for scaling up AX production. [ABSTRACT FROM AUTHOR]

Nucleotide substitutions have played an important role in molecular evolution, and understanding their dynamics would contribute to genetic studies. Related research with defined DNA sequences lasted for decades until whole-genome sequencing arose. UV radiation (UVR) can generate base changes and other genetic variations in a short period of time, so it would be more meaningful to explore mutations caused by UVR from a genomic perspective. The monokaryon enoki strain WT583 was selected as the experimental material in this study because it can spontaneously produce large amounts of oidia on PDA plates, and the monokaryons originating from oidia have the same genotype as their mother monokaryon. After exposure to UV radiation, 100 randomly selected mutants, with WT583 as the reference genome, were sent for genome sequencing. BWA, samtools, and GATK software were employed for SNP calling, and the R package CMplot was used to visualize the distribution of the SNPs on the contigs of the reference genome. Furthermore, a k-mer-based method was used to detect DNA fragment deletion. Moreover, the non-synonymous genes were functionally annotated. A total of 3707 single-base substitutions and 228 tandem mutations were analyzed. The immediate adjacent bases showed different effects on the mutation frequencies of adenine and cytosine. For adenine, the overall effects of the immediate 5′-side and 3′-side bases were T > A > C > G and A > T > G > C, respectively; for cytosine, the overall effects of the immediate 5′-side and 3′-side bases were T > C > A > G and C > T > A > G, respectively. Regarding tandem mutations, the mutation frequencies of double-transition, double-transversion, 3′-side transition, and 5′-side transition were 131, 8, 72, and 17, respectively. Transitions at the 3′-side with a high mutation frequency shared a common feature, where they held transversions at the 5′-side of A→T or T→A without covalent bond changes, suggesting that the sequence context of tandem motifs might be related to their mutation frequency. In total, 3707 mutation sites were non-randomly distributed on the contigs of the reference genome. In addition, pyrimidines at the 3′-side of adenine promoted its transversion frequency, and UVR generated DNA fragment deletions over 200 bp with a low frequency in the enoki genome. The functional annotation of the genes with non-synonymous mutation indicated that UVR could produce abundant mutations in a short period of time. [ABSTRACT FROM AUTHOR]

Under global change scenarios, the sea surface temperature is increasing steadily along with other changes to oceanic environments. Consequently, marine diatoms are influenced by multiple ocean global change drivers. We hypothesized that temperature rise mediates the responses of polar and temperate diatoms to UV radiation (UVR) to different extents, and exposed the temperate centric diatoms, Thalassiosira weissflogii and Skeletonema costatum, and a polar pennate diatom Entomoneis sp., to warming (+5°C) for 10 days, then performed short‐term incubations under different radiation treatments with or without UVR. The effective quantum yields of the three diatoms were stable during exposure to PAR, but decreased when exposed to PAR + UVR, leading to significant UV‐induced inhibition, which was 3% and 9%, respectively, for T. weissflogii and S. costatum under ambient temperature but increased to 12% and 17%, respectively, in the cells acclimated to the warming treatment. In contrast, UVR induced much higher inhibition, by about 45%, in the polar diatom Entomoneis sp. at ambient temperature, and the warming treatment alleviated the UV‐induced inhibition, which dropped to 36%. The growth rates were significantly inhibited by UVR in S. costatum under the warming treatment and in Entomoneis sp. under ambient temperature, while there was no significant effect for T. weissflogii. Our results indicate that the polar diatom was more sensitive to UVR though warming could alleviate its impact, whereas the temperate diatoms were less sensitive to UVR but warming exacerbated its impacts, implying that diatoms living in different regions may exhibit differential responses to global changes. [ABSTRACT FROM AUTHOR]

Using resilient, self-sustaining plants in urban green spaces enhances environmental and cultural benefits and reduces management costs. We assessed two spontaneous plant species, Linaria vulgaris Mill. and Cichorium intybus L., in four sites from the surrounding urban areas, ranging in altitude from 78 to 1040 m. Protection against UV-B radiation is crucial for plants at higher altitudes, guiding our focus on UV-visible absorption spectra, fluorometric emission spectra, secondary metabolite accumulation, and pigment dynamics in leaves. Our findings revealed a slight increase in UV-absorbing compounds with altitude and species-specific changes in visible spectra. The UV-emission of fluorochromes decreased, while red emission increased with altitude but only in chicory. Polyphenols and flavonoids showed a slight upward trend with altitude. Divergent trends were observed in condensed tannin accumulation, with L. vulgaris decreasing and C. intybus increasing with altitude. Additionally, chicory leaves from higher altitudes (792 and 1040 m) contained significantly lower triterpene concentrations. In L. vulgaris, chlorophyll pigments and carotenoids varied with sites, contrasting with UV absorbance variations. For C. intybus, pigment variation was similar to absorbance changes in the UV and VIS range, except at the highest altitude. These observations provide valuable insights into species-specific strategies for adapting to diverse environmental contexts. [ABSTRACT FROM AUTHOR]

Resistive metal/β-Ga2O3/metal structures with different interelectrode distances and electrode topologies were investigated. The oxide films were deposited by radio-frequency magnetron sputtering of a Ga2O3 (99.999%) target onto an unheated sapphire c-plane substrate (0001) in an Ar/O2 gas mixture. The films are sensitive to ultraviolet radiation with wavelength λ = 254. Structures with interdigital electrode topology have pronounced persistent conductivity. It is shown that the magnitude of responsivity, response time τr, and recovery time τd are determined by the concentration of free holes p involved in recombination processes. For the first time, it is proposed to consider hole trapping both by surface states Nts at the metal/Ga2O3 interface and by traps in the bulk of the film. [ABSTRACT FROM AUTHOR]

The effect of UV radiation on the accumulation of mycosporine-like amino acids (MAAs) and pigments was investigated on red macroalga Palmaria palmata cultivated for 21 days. The data were combined with the effect of NaNO3 to further investigate the synthesis of these nitrogenous compounds. A progressive decrease in both total MAA and pigment contents was observed, with a positive effect of nitrate supply. Usujirene was the only MAA exhibiting a significantly increasing content when exposed to UV radiation, changing from 9% to 24% of the total MAA's contribution, with no variation observed with NaNO3. This suggests a specific induction or synthesis pathway of usujirene for photoprotection, while the synthesis of other MAAs could have been limited by an insufficient amount of UV radiation and/or irradiance. The photoprotective ability of some MAAs could have been impacted by nitrogen starvation over time, resulting in a limited synthesis and/or potential use of MAAs as a nitrogen source for red macroalgae. The data confirmed the multiple effects of environmental factors on the synthesis of MAAs while providing new insights into the specific synthesis of usujirene, which could find an application in the cosmetics sector as natural sunscreen or an anti-ageing agent. [ABSTRACT FROM AUTHOR]

This study aimed to assess the changes occurring during the storage of tablets of three effervescent preparations available in Polish pharmacies containing calcium and quercetin from various manufacturers under stressful conditions (45 °C, UV radiation) using a hyperspectral Specim IQ camera (Finland), X-ray microtomography (Germany), and selected pharmacopoeial parameters. All measurements were made three times at the beginning of the experiment (day 0) and then on days 3 and 10. In general, for all analyzed preparations, the values of reflectance (within a range from visible light to near-infrared) were significantly higher on day 0 than after 10 days of heat and UV (p < 0.001 each). The hardness of the tablets of all analysed preparations was higher on days 3 and 10 compared to day 0. Significant differences were found in the density of the internal structure of the tested preparations (p < 0.001), but in Preparations 1 and 2 on day 10, the density was higher compared to the initial density. In contrast, the porosity was lower on day 10 than on day 0 for Preparations 1 and 2, while in Preparation 3, it remained the same. In conclusion, lower reflectance values indicate that more light passes through/into the tablet, and the increase in density and decrease in porosity may indicate changes in the microstructure of the tablets. [ABSTRACT FROM AUTHOR]

Cis-regulatory elements have an important role in human adaptation to the living environment. However, the lag in population genomic cohort studies and epigenomic studies, hinders the research in the adaptive analysis of cis-regulatory elements in human populations. In this study, we collected 4,013 unrelated individuals and performed a comprehensive analysis of adaptive selection of genome-wide cis-regulatory elements in the Han Chinese. In total, 12.34% of genomic regions are under the influence of adaptive selection, where 1.00% of enhancers and 2.06% of promoters are under positive selection, and 0.06% of enhancers and 0.02% of promoters are under balancing selection. Gene ontology enrichment analysis of these cis-regulatory elements under adaptive selection reveals that many positive selections in the Han Chinese occur in pathways involved in cell–cell adhesion processes, and many balancing selections are related to immune processes. Two classes of adaptive cis-regulatory elements related to cell adhesion were in-depth analyzed, one is the adaptive enhancers derived from neanderthal introgression, leads to lower hyaluronidase level in skin, and brings better performance on UV-radiation resistance to the Han Chinese. Another one is the cis-regulatory elements regulating wound healing, and the results suggest the positive selection inhibits coagulation and promotes angiogenesis and wound healing in the Han Chinese. Finally, we found that many pathogenic alleles, such as risky alleles of type 2 diabetes or schizophrenia, remain in the population due to the hitchhiking effect of positive selections. Our findings will help deepen our understanding of the adaptive evolution of genome regulation in the Han Chinese. [ABSTRACT FROM AUTHOR]

Avobenzone is one of the most widely used sunscreens in skin care formulations, but suffers from some drawbacks, including photo instability. To mitigate this critical issue, the use of octocrylene as a stabilizer is a common approach in these products. However, octocrylene has been recently demonstrated to show potential phototoxicity. The aim of this work is to analyze the performance of a series of mycosporine-like amino acid (MAA)-inspired compounds to act as avobenzone stabilizers as an alternative to octocrylene. Different avobenzone/MAA analogue combinations included in galenic formulations were followed under increasing doses of solar-simulated UV radiation. Some of the synthetic MAA analogues analyzed were able to increase by up to two times the UV dose required for 50% of avobenzone photobleaching. We propose some of these MAA analogues as new candidates to act as avobenzone-stabilizing compounds in addition to their UV absorbance and antioxidant properties, together with a facile synthesis. [ABSTRACT FROM AUTHOR]

In this study, we aimed to document the freshwater symbiotic interactions along with the impact of the abiotic environment and anthropogenic effects on the functionality of freshwater organisms. Symbiotic green hydra (Z) and free-living brown hydra (S), either separately or both species together, were treated with the herbicide norflurazon in concentrations of 2 × 10−6 mol/L (N6) and 2 × 10−7 mol/L (N7) for 72 h. Also, hydras were treated with both norflurazon and UV radiation at a wavelength of 254 nm for 2 min or were irradiated only. The next part of the experiment was performed in the same way but with added suspensions of isolated endosymbiotic alga, free-living alga, or both algae together. Mortality, migration, tentacle and tissue damage, changes in the thickness of the mesoglea of hydras, and clustering of algae were monitored. Green hydra generally showed lower rates of migration, and mortality was observed only in green hydra exposed to UV radiation. Tentacle damage was more pronounced in green hydra and included a specific fork-like structure. The use of cryofixation and TEM enabled us to partly elucidate the effect of clustering of algae. In summary, our study provides new insights into the influence of different environmental stressors and their combination on symbiotic and free-living freshwater hydras and algae and a better understanding of interactions in freshwater ecosystems. [ABSTRACT FROM AUTHOR]

ABSTRACT Earth’s stratosphere is characterized by hypobaric conditions, low temperatures, and high intensities of ultraviolet (UV) and cosmic radiation as well as low water and nutrient availability. While it is not considered a permanent habitat for microorganisms, they can be transported to the stratosphere by storms, volcanic action, or human activity. The impact of those extreme conditions on microorganisms and their survival were tested by sending a sample gondola to the stratosphere. The sample gondola was built to allow exposure of Bacillus subtilis endospores at different angles to the sun. It moreover had holders for three environmental samples to test the effect of stratospheric conditions on complex microbial communities. The gondola attached to a stratospheric balloon was launched near Kiruna, Sweden, ascended to ~25 km, and drifted eastward for ~200 km. Samples were exposed to pressures as low as 2 kPa and temperatures as low as −50°C as well as high UV radiation. Survival rates of B. subtilis were determined by comparing the numbers of colony-forming units (CFUs) for the different exposure angles. Survival was negatively correlated with exposure angle, indicating the significant impact of UV radiation. The effect of stratospheric conditions on environmental samples was assessed by comparing most probable numbers, microbial community composition, and substrate-use profiles to controls that had stayed on the ground. Cultivation was possible from all samples with survival rates of at least 1%, and differences in community composition were observed. Survival of environmental microorganisms might have been supported by the sample matrix, which provided protection from radiation and desiccation.IMPORTANCEEarth's stratosphere is a hostile environment that has challenged microbial survival. We set out to test the effect of stratosphere exposure on survival of single species (Bacillus subtilis) and complex microbial communities from soils and sediment. B. subtilis survival was strongly impacted by sun exposure, i.e., ultraviolet (UV) radiation, with only 1% survival at full sun exposure. Complex microbial communities had high survival rates, and the soil or sediment matrix may have provided protection against radiation and desiccation, supporting the survival of environmental microorganisms.

In order to modify the surface as well as mechanical properties, polycarbonate (PC) films were grafted with two types of monomers such as 2-hydroxyethylmethacrylate (HEMA) & N-vinyl pyrrolidone (NVP). Material preparation is carried out by a periodic orientation of monomer solutions having methanol of dissimilar concentration in addition with photo-initiator [Irgacure 907]. Polycarbonate (PC) films were cut into dumbbell shape (10 × 3) mm [ASTM], impregnated into the devised solutions and irradiated under both ultraviolet (UV) and Co-60 gamma radiation. Extent of polymer loading (PL) (%) was calculated in order to assess the amount of grafted polycarbonate (PC-g-HEMA) formed under certain conditions of the experiment. Various property parameters such as elongation at break, tensile strength, modulus, absorption of water, gel content etc. were studied. 30% HEMA and 120-min irradiation time showed the better grafting with respect to the qualities studied. Water absorption was found much low by the treated (PC-g-HEMA) samples with compared to the untreated samples. The loss of mechanical property in grafted polycarbonate due to UV aging and simulating weathering degradation was found higher in untreated polycarbonate than that of grafted one. Effect of monomer N-vinyl pyrrolidone (NVP) on to PC films under UV radiation was also examined and various mechanical properties (tensile strength, polymer loading, elongation at break and tensile modulus) were studied. 20% NVP with the duration of 240 min irradiation time showed the maximum mechanical properties. The sample was found to destroy up to the concentration of 20% NVP.

Mitochondrial (mt) DNA can be classified into haplogroups, which represent populations with different geographic origins. Individuals of maternal African backgrounds (L haplogroup) are more prone to develop specific diseases compared those with maternal European-H haplogroups. Using a cybrid model, effects of amyloid-β (Amyβ), sub-lethal ultraviolet (UV) radiation, and 5-Aza-2'-deoxycytidine (5-aza-dC), a methylation inhibitor, were investigated. Amyβ treatment decreased cell metabolism and increased levels of reactive oxygen species in European-H and African-L cybrids, but lower mitochondrial membrane potential (ΔΨM) was found only in African-L cybrids. Sub-lethal UV radiation induced higher expression levels of CFH, EFEMP1, BBC3, and BCL2L13 in European-H cybrids compared to African-L cybrids. With respect to epigenetic status, the African-L cybrids had (a) 4.7-fold higher total global methylation levels (p = 0.005); (b) lower expression patterns for DNMT3B; and (c) elevated levels for HIST1H3F. The European-H and African-L cybrids showed different transcription levels for CFH, EFEMP1, CXCL1, CXCL8, USP25, and VEGF after treatment with 5-aza-dC. In conclusion, compared to European-H haplogroup cybrids, the African-L cybrids have different (i) responses to exogenous stressors (Amyβ and UV radiation), (ii) epigenetic status, and (iii) modulation profiles of methylation-mediated downstream complement, inflammation, and angiogenesis genes, commonly associated with various human diseases.

Avobenzone is one of the most widely used sunscreens in skin care formulations, but suffers from some drawbacks, including photo instability. To mitigate this critical issue, the use of octocrylene as a stabilizer is a common approach in these products. However, octocrylene has been recently demonstrated to show potential phototoxicity. The aim of this work is to analyze the performance of a series of mycosporine-like amino acid (MAA)-inspired compounds to act as avobenzone stabilizers as an alternative to octocrylene. Different avobenzone/MAA analogue combinations included in galenic formulations were followed under increasing doses of solar-simulated UV radiation. Some of the synthetic MAA analogues analyzed were able to increase by up to two times the UV dose required for 50% of avobenzone photobleaching. We propose some of these MAA analogues as new candidates to act as avobenzone-stabilizing compounds in addition to their UV absorbance and antioxidant properties, together with a facile synthesis.

The main purpose of this study was to create a prototype of an unmanned aerial system equipped with intelligent hardware and software technologies necessary for surveillance and monitoring the health and growth of crops from orchards with vines and fruit trees. Using low-cost sensors that accurately measure ultraviolet solar radiation was an important objective. The device, which needed to be attached to the commercial DJI Mini 4 Pro drone, had to be small, portable, and have low energy consumption. For this purpose, the widely used Vishay VEML6075 digital optical sensor was selected and implemented in a prototype, alongside a Raspberry Pi Zero 2 W minicomputer. To collect data from these sensors, a program written in Python was used, containing specific blocks for data acquisition from each sensor, to facilitate the monitoring of ultraviolet (UV) radiation, or battery current. By analyzing the data obtained from the sensors, several important conclusions were drawn that may provide valuable pathways for the further development of mobile or modular equipment. Furthermore, the plantation state analysis results with proposed models in the geographic information system (GIS) environment are also presented. The visualization of maps indicating variations in vegetation conditions led to identifying problems such as hydric stress.

The estuarine anemone Anthopleura hermaphroditica and its symbiont Philozoon anthopleurum are continuously exposed to intense fluctuations in solar radiation and salinity owing to tidal changes. The aim of this study was to evaluate the effects of the tidal cycle, solar radiation, and salinity fluctuations on the photosynthetic and cellular responses (lipid peroxidation, total phenolic compounds, and antioxidant activity) of the symbiont complex over a 24 h period in the Quempillén River Estuary. Additionally, laboratory experiments were conducted to determine the specific photobiological responses to photosynthetically active radiation (PAR), ultraviolet radiation (UVR), and salinity. Our field results showed that the photosynthetic parameters of the symbiont complex decreased with increasing ambient radiation; however, no relationship was observed with changes in salinity. Increased peroxidative damage, total phenolic compound levels, and antioxidant activity were mainly related to increased UVR and, to a lesser extent, PAR. During the dark period, only PAR-exposed organisms returned to the basal levels of photosynthesis and cell damage. Laboratory exposure confirmed the deleterious effects of UVR on the photosynthetic response. The present study suggests that the ability of A. hermaphroditica to acclimate to natural radiation stress is mediated by the concerted action of various physiological mechanisms that occur at different times of the day, under varying levels of environmental stress.

The effects of UV radiation, a maleic anhydride grafted polyethylene (MAPE) coupling agent and moisture cycling exposure on wood plastic composites (WPC) made from pinewood waste (PW) and high-density polyethylene (HDPE) on their tensile and flex properties, were studied. First, the effect of UV radiation and the presence of anhydride grafted polyethylene on the absorption-desorption behavior of the compounds was evaluated and then its effect on the mechanical properties. Scanning electron microscopy (SEM) was used to analyze the surfaces of the samples subjected to these factors and their subsequent damage in fracture zones of the samples. The moisture absorption-desorption process exhibited a two-stage mechanism: the first is significant increases in the absorption values in the first five cycles, and a second stabilization stage that occurs from the sixth cycle onwards. The first stage includes several steps: initial absorption and delamination; capillary action and polymer-wood interaction; and swelling, fiber-matrix interaction and mechanical damage. The second stage involves the balance and stabilization step. Statistically, it was found that the changes in the humidity values in the absorption and desorption cycles show that UV radiation has a significant contribution with the effect of increasing the absorption and desorption values, while the presence of anhydride grafted polyethylene as a lesser effect with an effect of decreasing those values. The tensile and flexural properties of the compounds were significantly affected by UV radiation and moisture cycling. Taking the sample without anhydride grafted polyethylene and without treatments as a reference, only a slight increase of 5–12% in its tensile and flexural properties was observed, while treatments with UV radiation and absorption-desorption cycles reduced them by up to 45%. The SEM analysis confirmed the deterioration of the composites in the form of microcracks, delamination, interfacial voids and mechanical failures in both the wood filler and the polyethylene matrix, especially in the samples exposed to ultraviolet radiation, where this deterioration was lower in the samples containing anhydride grafted polyethylene.

Background: UV radiation can cause serious skin and eye diseases, especially cancers. UV-related skin cancer incidences have been increasing for decades. The determining factor for this development is the individual UV exposure. Climate change-induced changes in atmospheric factors can influence individual UV exposure. Methods: On the basis of a topic-specific literature research, a review paper was prepared and supplemented by as yet unpublished results of the authors’ own studies. The need for scientific research and development is formulated as well as primary prevention recommendations. Results: Climate change alters the factors influencing UV irradiance and annual UV dose in Germany. First evaluations of satellite data for Germany show an increase in mean peak UV irradiance and annual UV dose for the last decade compared to the last three decades. Conclusions: The climate change-related influences on individual UV exposure and the associated individual disease incidence cannot yet be reliably predicted due to considerable uncertainties. However, the current UV-related burden of disease already requires primary preventive measures to prevent UV-related diseases.

IntroductionDaily solar ultraviolet (UV) radiation has an important impact on skin health. Understanding the initial events of the UV-induced response is critical to prevent deleterious conditions. However, studies in human volunteers have ethical, technical, and economic implications that make skin equivalents a valuable platform to investigate mechanisms related to UV exposure to the skin. In vitro human skin equivalents can recreate the structure and function of in vivo human skin and represent a valuable tool for academic and industrial applications. Previous studies have utilised non-pigmented full-thickness or pigmented epidermal skin equivalents to investigate skin responses to UV exposure. However, these do not recapitulate the dermal-epidermal crosstalk and the melanocyte role in photoprotection that occurs in vivo. In addition, the UV radiation used in these studies is generally not physiologically representative of real-world UV exposure.MethodsWell-characterised pigmented and non-pigmented skin equivalents that contain human dermal fibroblasts, endogenous secreted extracellular matrix proteins (ECM) and a well-differentiated and stratified epidermis have been developed. These constructs were exposed to UV radiation for ×5 consecutive days with a physiologically relevant UV dose and subsequently analysed using appropriate end-points to ascertain photodamage to the skin.ResultsWe have described that repeated irradiation of full-thickness human skin equivalents in a controlled laboratory environment can recreate UV-associated responses in vitro, mirroring those found in photoexposed native human skin: morphological damage, tanning, alterations in epidermal apoptosis, DNA lesions, proliferation, inflammatory response, and ECM-remodelling.DiscussionWe have found a differential response when using the same UV doses in non-pigmented and pigmented full-thickness skin equivalents, emphasising the role of melanocytes in photoprotection.

In the present study, hybrid activation of sodium peroxydisulfate (PS) by hydrodynamic cavitation and ultraviolet radiation was investigated for Congo Red (CR) degradation. Experiments were conducted using the Box-Benken design on inlet pressure (2–6 bar), PS concentration (0–50 mg. L−1) and UV radiation power (0–32 W). According to the results, at the optimum point where the pressure, PS concentration and UV radiation power were equal to 4.5 bar, 30 mg. L−1 and 16 W respectively, 92.01% of decolorization was achieved. Among the investigated processes, HC/UV/PS was the best process with the rate constant and synergetic coefficient of 38.6 × 10−3 min−1 and 2.76, respectively. At the optimum conditions, increasing the pollutant concentration from 20 mg. L−1 to 80 mg. L−1 decrease degradation rate from 92.01 to 45.21. Presence of natural organic mater (NOM) in all concentrations inhibited the CR degradation. Quenching experiments revealed that in the HC/UV/PS hybrid AOP free radicals accounted for 63.4% of the CR degradation, while the contribution of sulfate (SRs) and hydroxyl radicals (HRs) was 53.1% and 46.9%, respectively.

The high-mountain lakes of the Alps, perched like glistening gems in the cradle of Europe’s most formidable mountain range, have for generations epitomized nature’s majesty. These remote and pristine bodies of water have served as invaluable sentinels of global change, repositories of geological history, and sources of freshwater for the surrounding regions. Yet, despite their seemingly imperturbable beauty and seclusion, these high-mountain lakes are not immune to the evolving forces of our changing world. Re-emerging threats, exacerbated by the relentless march of climate change and intensified human activities, cast a shadow over their future, posing profound challenges that demand our attention. The aim of this perspective is to shed light on the main emerging threats, raise awareness, and advocate for proactive actions aimed at preserving and protecting high-mountain lakes. These threats include climate change, retreat of glaciers, UV radiation, long-range transport of contaminants, impact of alien species and water usage for Alpine storage power stations. Additionally, increased tourism and recreational activities in these pristine environments can cause habitat disturbance, further endangering these unique ecosystems. The present perspective article also offers valuable perspectives on the necessity of monitoring and research efforts in high-mountain lakes. Such actions are crucial for comprehending the ecological well-being of these ecosystems, evaluating the consequences of environmental shifts, and devising successful conservation strategies.

Photochemical reactions in cell DNA are induced in various organisms by solar UV radiation and may lead to a series of biological responses to DNA damage, including apoptosis, mutagenesis, and carcinogenesis. The chemical nature and the amount of DNA lesions depend on the wavelength of UV radiation. UV type B (UVB, 290–320 nm) causes two main lesions, cyclobutane pyrimidine dimers (CPDs) and, with a lower yield, pyrimidine (6-4) pyrimidone photoproducts (6-4PPs). Their formation is a result of direct UVB photon absorption by DNA bases. UV type A (UVA, 320–400 nm) induces only cyclobutane dimers, which most likely arise via triplet–triplet energy transfer (TTET) from cell chromophores to DNA thymine bases. UVA is much more effective than UVB in inducing sensitized oxidative DNA lesions, such as single-strand breaks and oxidized bases. Of the latter, 8-oxo-dihydroguanine (8-oxodG) is the most frequent, being produced in several oxidation processes. Many recent studies reported novel, more detailed information about the molecular mechanisms of the photochemical reactions that underlie the formation of various DNA lesions. The information is mostly summarized and analyzed in the review. Special attention is paid to the oxidation reactions that are initiated by reactive oxygen species (ROS) and radicals generated by potential endogenous photosensitizers, such as pterins, riboflavin, protoporphyrin IX, NADH, and melanin. The review discusses the role that specific DNA photoproducts play in genotoxic processes induced in living systems by UV radiation of various wavelengths, including human skin carcinogenesis. [ABSTRACT FROM AUTHOR]

Laser‐induced periodic surface structures (LIPSS) represent a unique route for functionalizing materials through the fabrication of surface nanostructures. Commercial AISI 316L stainless steel (SS316L) surfaces are laser treated by ultraviolet 300 ps laser pulses in a laser line scanning (LLS) approach. Processing parameters are optimized (pulse energy of 2.08 µJ, pulse repetition frequency of 300 kHz, and suitable laser scan and sample displacement rates) for the generation of low spatial frequency LIPSS over a large 25 × 25 mm2 area. Different angles of incidence of the laser radiation (0°, 30°, and 45°) and different linear laser beam polarizations (s and p) produce a plethora of rippled surface morphologies at distinct grains. Scanning electron microscopy and 2D Fourier transforms, together with calculations of the optical energy deposited at the treated surfaces using Sipe's first‐principles electromagnetic scattering theory, are used to study and analyze in detail these surface morphologies. Combined with electron backscattering diffraction, analyses allow associating site‐selectively various laser‐induced‐surface morphologies with the underlying crystalline grain orientation. Resulting grain orientation maps reveal a strong impact of the grain crystallographic orientation on LIPSS formation and point toward possible strategies, like multi‐step processes, for improving the manufacturing of LIPSS and their areal coverage of polycrystalline technical materials. [ABSTRACT FROM AUTHOR]

This study aimed to explore the published research on the relationship between climate change and skin cancer and the implications for prevention, management and further research. Scoping review. This scoping review following JBI methodology reviewed English articles identified in searches of MEDLINE, Embase, CINAHL, Web of Science and Scopus on 14 April 2023. The screening of articles was completed by two independent reviewers. Data were extracted by a single reviewer and checked by another. A causal pathway diagram was iteratively developed throughout the review and was used to categorise the findings. The search identified 1376 papers, of which 45 were included in the final review. Nine papers reported primary research, and 36 papers were reviews, perspectives, commentaries, editorials, or essays. The papers examined climate change influencing behaviours related to ultraviolet exposure (30 papers), ambient temperature (21 papers) and air pollution (five papers) as possible risk factors; occupational, rural, and contextual factors affecting skin cancer (11 papers); and prevention and access to health care in the context of climate change (seven papers). Most papers were published in journals in subject areas other than health. This review identified ultraviolet radiation, occupation, rising temperature, individual behaviour and air pollution as possible influences on skin cancer rates. Furthermore, it highlights the complexity and uncertainties in the relationship between climate change and skin cancer and the need for further research on this relationship, including primary epidemiological research and reviews that follow recognised review guidelines and include assessment of health services and social determinants in the causal pathways of this relationship. [ABSTRACT FROM AUTHOR]

The durability and long-term performance of poly(vinyl chloride) (PVC) are significantly influenced by its photostability. In this study, we modified PVC using a special heterocyclic molecule and combined it with nano-metallic oxides in order to improve its photostability. In order to create the modified PVC, 5-amino-1,3,4-thiadiazole-2-thiol had to react with PVC. This caused the heterocyclic molecule to be substituted for by the thiol group and incorporated into the polymer's backbone. Additionally, nanoparticles of calcium oxide (CoO), nickel oxide (NiO), or chromium oxide (CrO) were added to the modified PVC. Several methods were used to characterize the generated materials. The effective incorporation of the heterocyclic molecule into the modified PVC was validated by Fourier-transform infrared (FTIR) spectroscopy. While changes in the chemical shifts connected to the modification were discovered using proton nuclear magnetic resonance (1H NMR) spectroscopy. Energy-dispersive X-ray spectroscopy (EDX) in conjunction with scanning electron microscopy (SEM) revealed details on the surface shape and elemental makeup of the modified PVC films. By measuring weight loss percentages and utilizing FTIR spectroscopy, the photostability of the modified PVC films was assessed. According to FTIR measurements, the modified PVC sheets showed less production of carbonyl and alkene groups after UV irradiation, indicating less deterioration than blank PVC. Experiments on weight loss percentage showed that the modified PVC sheets had increased photostability since they lost much less weight than unmodified PVC. Additionally, the photostability was improved by mixing the modified PVC with nano-metallic oxides (CoO, NiO, and CrO). After being exposed to UV radiation, the blended modified PVC films' FTIR spectra showed less intensity of the carbonyl, alkene, and hydroxy groups, demonstrating the effectiveness of the additions in reducing deterioration. As a result, adding nano-metallic oxides to PVC and altering it with a special heterocyclic molecule have both been successful in increasing the photostability of PVC films. After being exposed to UV radiation, the modified PVC showed lessened degradation product production and less weight loss, indicating increased photodegradation resistance. These discoveries aid in the creation of PVC-based materials that are more dependable and long-lasting, with potential uses across numerous industries. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hyperpigmentation, characterized by the excessive accumulation of melanin in the skin, is a common dermatological concern triggered by various factors, including UV radiation exposure. This study investigates the potential of grapevine leaf extracts in treating hyperpigmentation induced by UV radiation, focusing on 11 European and 12 Israeli grapevine varieties. Our research explores the correlations between total polyphenol content (TPC), tyrosinase inhibition, sun protection factor (SPF), and half-maximal inhibitory concentration (IC50) of these extracts. Our findings reveal substantial variation in TPC among grapevine varieties' leaves, with the Israeli varieties showing higher TPC levels than the European ones. Correlation analysis demonstrates a robust link between TPC and SPF, indicating that increased TPC contributes to enhanced sun protection properties. However, TPC alone does not strongly correlate with tyrosinase inhibition, suggesting the importance of specific polyphenols in tyrosinase inhibition. Furthermore, the study identifies specific peaks in the HPLC analysis that correlate with desired activities. In summary, our research highlights the potential of grapevine leaf extracts, especially those from Israeli indigenous varieties, in addressing hyperpigmentation. It emphasizes the importance of specific polyphenols rather than TPC alone in achieving the desired effects. These findings open doors for further investigation into identifying and isolating active compounds from grapevine leaves for skincare applications. [ABSTRACT FROM AUTHOR]

This study presents the effect of ultra-violet (UV) light radiation on the process kinetics, metabolic performance, and biodegradation capability of Scenedesmus vacuolatus. The impact of the UV radiation on S. vacuolatus morphology, chlorophyll, carotenoid, carbohydrates, proteins, lipid accumulation, growth rate, substrate affinity and substrate versatility were evaluated. Thereafter, a preliminary biodegradative potential of UV-exposed S. vacuolatus on spent coolant waste (SCW) was carried out based on dehydrogenase activity (DHA) and total petroleum hydrocarbon degradation (TPH). Pronounced structural changes were observed in S. vacuolatus exposed to UV radiation for 24 h compared to the 2, 4, 6, 12 and 48 h UV exposure. Exposure of S. vacuolatus to UV radiation improved cellular chlorophyll (chla = 1.89-fold, chlb = 2.02-fold), carotenoid (1.24-fold), carbohydrates (4.62-fold), proteins (1.44-fold) and lipid accumulations (1.40-fold). In addition, the 24 h UV exposed S. vacuolatus showed a significant increase in substrate affinity (1/Ks) (0.959), specific growth rate (µ) (0.024 h−1) and biomass accumulation (0.513 g/L) by 1.50, 2 and 1.9-fold respectively. Moreover, enhanced DHA (55%) and TPH (100%) degradation efficiency were observed in UV-exposed S. vacuolatus. These findings provided major insights into the use of UV radiation to enhance S. vacuolatus biodegradative performance towards sustainable green environment negating the use of expensive chemicals and other unfriendly environmental practices. [ABSTRACT FROM AUTHOR]

The aim was to determine the response of a bloom-forming Microcystis aeruginosa to climatic changes. Cultures of M. aeruginosa FACHB 905 were grown at two temperatures (25°C, 30°C) and exposed to high photosynthetically active radiation (PAR: 400-700 nm) alone or combined with UVR (PAR + UVR: 295-700 nm) for specified times. It was found that increased temperature enhanced M. aeruginosa sensitivity to both PAR and PAR + UVR as shown by reduced PSII quantum yields (Fv/Fm) in comparison with that at growth temperature (25°C), the presence of UVR significantly exacerbated the photoinhibition. M. aeruginosa cells grown at high temperature exhibited lower PSII repair rate (Krec) and sustained nonphotochemical quenching (NPQs) induction during the radiation exposure, particularly for PAR + UVR. Although high temperature alone or worked with UVR induced higher SOD and CAT activity and promoted the removal rate of PsbA, it seemed not enough to prevent the damage effect from them showing by the increased value of photoinactivation rate constant (Kpi). In addition, the energetic cost of microcystin synthesis at high temperature probably led to reduced materials and energy available for PsbA turnover, thus may partly account for the lower Krec and the declination of photosynthetic activity in cells following PAR and PAR + UVR exposure. Our findings suggest that increased temperature modulates the sensitivity of M. aeruginosa to UVR by affecting the PSII repair and defense capacity, thus influencing competitiveness and abundance in the future water environment. [ABSTRACT FROM AUTHOR]