Ultraviolet Radiation Research Articles

Uncovering genetic loci and biological pathways associated with age-related cataracts through GWAS meta-analysis

Age-related cataracts is a highly prevalent eye disorder that results in the clouding of the crystalline lens and is one of the leading causes of visual impairment and blindness. The disease is influenced by multiple factors including genetics, prolonged exposure to ultraviolet radiation, and a history of diabetes. However, the extent to which each of these factors contributes to the development of cataracts remains unclear. Our study identified 101 independent genome-wide significant loci, 57 of which are novel. We identified multiple genes and biological pathways associated with the cataracts, including four drug-gene interactions. Our results suggest a causal association between type 1 diabetes and cataracts. Also, we highlighted a surrogate measure of UV light exposure as a marker of cataract risk in adults.

Indicators for Assessing the Combustion Intensity of Coal Particles Using a Single UV Sensor

This paper deals with the evaluation of the combustion intensity of coal particles on the basis of measurement data (UV radiation) from a scanning point photodiode. UV radiation is measured using a custom UV scanner at different distances from the burner in the vertical combustion chamber. The designed scanner uses a sensitive silicon carbide (SiC) photodiode, and its dynamical properties are investigated in the present work. Subsequently, experiments are performed for coal particles at different combustion temperatures and at different measuring locations of the scanner. The measurement data are processed in the frequency domain using the proposed algorithm, and two indicators for evaluating the combustion intensity are proposed. The obtained results show that the proposed indicators provide unequivocal information about the combustion intensity as a function of the combustion temperature.

The potential cutaneous benefits of bentonites and montmorillonites.

Bentonites and montmorillonites, natural clay minerals originating from volcanic ash, possess unique properties that have traditionally been utilized in industrial applications. Recently, their potential biomedical applications, particularly in dermatology, have garnered significant interest. This review explores the cutaneous benefits of bentonites and montmorillonites, highlighting their anti-inflammatory, wound-healing, oil-absorbing, drug delivery, photoprotective, and anti-aging effects. Evidence from in vitro experiments, animal studies, and preliminary clinical trials demonstrate that these clays can significantly reduce inflammation, accelerate wound healing, absorb excess oil, enhance drug delivery, protect against ultraviolet radiation, and improve skin hydration and elasticity. Larger scale randomized clinical trials (RCTs) are needed to further establish the safety and efficacy of bentonites and montmorillonites. Given the increasing consumer demand for natural ingredients in skincare, bentonites and montmorillonites present a promising area for further research and development in dermatologic applications.

Upconversion Phosphor-Driven Photodegradation of Plastics.

Plastic waste poses a profound threat to ecosystems and human health, necessitating novel strategies for effective degradation in nature. Here, we present a novel approach utilizing upconversion phosphors as additives to significantly accelerate plastic photodegradation in nature via enhancing ultraviolet (UV) radiation. Pr-doped Li2CaGeO4 (LCGO:Pr) upconversion phosphors readily converting blue light into deep-UV radiation, dramatically improve photodegradation rates for polyethylene (PE) and polyethylene terephthalate (PET) microplastics. In situ spectroscopic studies show that upconversion fluorescence initiates the photophysical cleavage of C-C and C-O bonds in the backbones of PE and PET, resulting in plastic degradation. Moreover, incorporating LCGO:Pr into polypropylene (PP) sheets realizes markedly enhanced photodamage, with the cracking area increasing by nearly 38-fold under simulated sunlight for 10 days. This underscores the potential of employing this approach for the construction of light-driven destructible polymers. Further optimization and exploration of material compatibility hold promise for developing sustainable photodegradable plastics.

Epidemiological, clinical and therapeutic aspects of pterygium at the district hospital of Commune VI, Bamako Mali

Pterygium is a benign conjunctivo-elastic neoformation of the ocular surface with a triangular shape, canthal base and corneal apex. It extends into the area of the palpebral cleft, preferably in the nasal sector, towards the corneal apex. It is therefore easy to imagine the harmful consequences of its progression on vision The distribution of pterygium is global, but its prevalence is higher in hot, dry climates. Populations living in warm, desert environments, located in peri-equatorial regions at latitudes of 37° north and south of the equator and highly exposed to ultraviolet radiation are at higher risk of developing this disease During our study, we collected 83 cases of pterygium, a frequency of 0.36%. More than half, or 70%, of our patients were women with a sex ratio M/F: 0.36. The age group over 60 years old was the most represented with 26.51%. Itching dominated the warning signs with 36.14%. Stage II was in the majority with 51.81%. Nasal pterygium was the most common with 90%. All our patients have benefited from an excision of the pterygium with autograft of the same eye. We recorded 7 cases of recidivism, i.e. 8.43%. Pterygium, although benign, is a public health problem since, for any type of surgery involved, it is impossible to avoid recurrences, which characterize the disease. In Bamako, at the hospital of the district of commune VI, the evolution was unpredictable but seems more favorable with the limboconjunctival autograft Keywords: surgery, pterygium, commune VI, Bamako.

P2RY6 deletion promotes UVB-induced skin carcinogenesis by activating the PI3K/AKT signal pathway.

Our previous research has demonstrated that P2RY6 functions as an oncogene in DMBA/TPA-induced two-stage chemical skin carcinogenesis in mice. However, considering that human skin cancer is predominantly attributed to UV radiation from sunlight, additional investigations are needed to elucidate the role of P2RY6 in UVB-induced skin carcinogenesis. Surprisingly, we found that P2ry6-deficient mice exhibited marked promotion to UVB-induced skin papilloma formation compared with wild-type mice, suggesting its tumor-suppressive role in UVB-induced skin cancer. Additionally, a P2ry6 gene knockout promoted skin hyperplasia induced by short-term UVB irradiation, while UDP, the ligand of P2RY6, could inhibit the short-term UVB-induced increase of epiderma thickness in mouse skin. Furthermore, UVB irradiation could significantly upregulate P2RY6 expression in human and mouse skin cells. These results indicated that P2RY6 may play a crucial protective role in resisting the UVB-induced formation of skin tumors. At the molecular level, the loss of the P2RY6 gene inhibits the ubiquitination modification and expression of XPC after UVB irradiation in skin keratinocytes, resulting in the accumulation of CPDs (cyclobutane pyrimidine dimers). We have also demonstrated that P2RY6 deletion activates the PI3K/AKT signaling pathway both invitro and invivo. The CPD accumulation and acute inflammatory response enhanced by the loss of the P2RY6 gene can be reversed by an AKT inhibitor. These findings suggest that P2RY6 may act as a tumor suppressor in UVB-induced skin cancer by regulating the PI3K/AKT signaling pathway.

Enhancing biomass, hydrocarbon and biodiesel properties of green microalga Botryococcus braunii KMITL through gamma and UV radiation exposure.

This study investigated the effects of gamma (137Cs, 0-250Gy) and UV (UV-C, 0-12h) radiation on growth and biodiesel properties of Botryococcus braunii KMITL. For gamma radiation, maximum biomass (1.37 ± 0.02g L-1) was achieved with 50Gy, while a dose of 200Gy resulted in the highest hydrocarbon content (51.84 ± 0.20%) and yield (0.66 ± 0.01g L-1). For UV radiation, a 9h exposure produced the highest biomass (2.45 ± 0.05g L-1), hydrocarbon content (55.01 ± 1.22%), and yield (1.35 ± 0.04g L-1). Algae exposed to gamma radiation within the range of 0-150Gy exhibited C16:0 as the dominant fatty acid methyl ester (FAME), similar to those exposed to UV radiation, while algae exposed to 200-250Gy displayed C18:1n9t as the dominant FAME. High levels of gamma and UV radiation were observed to lengthen fatty acid chains and increase unsaturated fatty acids. The cetane values of biodiesel from algae exposed to gamma and UV radiation ranged from 64.55 ± 0.14-66.47 ± 0.20 and 59.43 ± 0.04-65.27 ± 0.22, respectively, all meeting standard criteria. Both gamma and UV radiation also improved the saponification value and cold flow properties of the biodiesel. These findings suggest that controlled levels of gamma and UV radiation effectively enhance hydrocarbon yields with significant implications for biofuel production.

Experimental Research on Basalt Fabric-Based Composites for Protection Against Contact Heat

ABSTRACT The unique properties of basalt fibers, i.e. low thermal conductivity, thermal resistance up to 800°C, biodegradability, resistance to acids and alkalis, corrosion, ultraviolet radiation, and non-flammability, make them increasingly used in personal protective equipment. The design and production of basalt fabric-based composites were performed, and composite layers were directly modified by depositing thin coatings using the magnetron sputtering method. The designing and testing were performed in five stages. For direct basalt fabric modification and basalt fabric-based composites, resistance to contact heat was tested for contact temperatures of 100°C and 250°C. Moreover, the uncertainty budgets of the threshold time measurement results were determined and analyzed for all composites. New basalt fabric-based composites were designed to protect users from contact heat in hot work environments. As a result of the research, it was found that applying composite coatings: aluminum and zirconium dioxide or aluminum and zirconium dioxide and titanium dioxide to both composite layers proved to be effective in obtaining composites that guarantee perfect resistance to contact heat up to 250°C.

Extending the acute skin response spectrum to include the far-UVC.

Guidance on maximal limits for ultraviolet (UV) exposure has been developed by national and international organizations to protect against adverse effects on human skin and eyes. These guidelines consider the risk of both acute effects (i.e., erythema and photokeratitis) and delayed effects (e.g., skin and ocular cancers) when determining exposure limits, and specify the dose a person can safely receive during an 8-h period without harmful effects. The determination of these exposure limits relies on the action spectra of photobiological responses triggered by UV radiation that quantify the effectiveness of each wavelength at eliciting each of these effects. With growing interest in using far-UVC (200-235 nm) radiation to control the spread of airborne pathogens, recent arguments have emerged about revisiting exposure limits for UV wavelengths. However, the standard erythema action spectrum, which provides some of the quantitative basis for these limits, has not been extended below 240 nm. This study assists to expand the erythema action spectrum to far-UVC wavelengths using a hairless albino mice model. We estimate that inducing acute effects on mouse skin with 222 nm radiation requires a dose of 1162 mJ/cm2, well above the current ACGIH skin exposure limit of 480 mJ/cm2.

Fluorescent Tetraphenylethylene-Based Cerium Metal-Organic Frameworks for White-Light-Emitting Diodes.

Discovery of highly efficient and thermal stable phosphors is the focus of the studies in phosphor-converted white light-emitting diodes (LEDs). Herein, a tetraphenylethylene-based cerium metal-organic framework (SYNU-2) was synthesized and characterized. The intricate architecture of SYNU-2 shows an overall 3D → 3D 2-fold interpenetration framework. SYNU-2 exhibited good luminescence properties, and its latent fingerprint developer was prepared, which showed good fluorescence and stability under ultraviolet (UV) radiation. It is worth noting that a prototype WLED device can be designed using SYNU-2 and red phosphors (Ca,Sr)AlSiN3:Eu2+ with CIE coordinates of (0.33, 0.33) at an applied 3 V bias.

Dermal Papilla Cells: From Basic Research to Translational Applications.

As an appendage of the skin, hair protects against ultraviolet radiation and mechanical damage and regulates body temperature. It also reflects an individual's health status and serves as an important method of expressing personality. Hair loss and graying are significant psychosocial burdens for many people. Hair is produced from hair follicles, which are exclusively controlled by the dermal papilla (DP) at their base. The dermal papilla cells (DPCs) comprise a cluster of specialized mesenchymal cells that induce the formation of hair follicles during early embryonic development through interaction with epithelial precursor cells. They continue to regulate the growth cycle, color, size, and type of hair after the hair follicle matures by secreting various factors. DPCs possess stem cell characteristics and can be cultured and expanded in vitro. DPCs express numerous stemness-related factors, enabling them to be reprogrammed into induced pluripotent stem cells (iPSCs) using only two, or even one, Yamanaka factor. DPCs are an important source of skin-derived precursors (SKPs). When combined with epithelial stem cells, they can reconstitute skin and hair follicles, participating in the regeneration of the dermis, including the DP and dermal sheath. When implanted between the epidermis and dermis, DPCs can induce the formation of new hair follicles on hairless skin. Subcutaneous injection of DPCs and their exosomes can promote hair growth. This review summarizes the in vivo functions of the DP; highlights the potential of DPCs in cell therapy, particularly for the treatment of hair loss; and discusses the challenges and recent advances in the field, from basic research to translational applications.

A Comparative Study of the Chemical Composition and Skincare Activities of Red and Yellow Ginseng Berries.

This study was conducted to investigate the differences in chemical composition between red (RGBs) and yellow ginseng berries (YGBs) and their whitening and anti-aging skincare effects. The differences in the chemical composition between RGB and YGB were analyzed by ultra-high-performance liquid chromatography tandem quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-Q-Exactive-MS/MS) combined with multivariate statistics. An aging model was established using UVB radiation induction, and the whitening and anti-aging effects of the two ginseng berries were verified in vitro and in vivo using cell biology (HaCaT and B16-F10 cells) and zebrafish model organisms. A total of 31 differential compounds, including saponins, flavonoids, phenolic acids, and other chemical constituents, were identified between the two groups. Superoxide dismutase (SOD) activity was more significantly increased (p < 0.05) and malondialdehyde (MDA) content was more significantly decreased (p < 0.01) in RGB more than YGB induced by UVB ultraviolet radiation. In terms of whitening effects, YGB was more effective in inhibiting the melanin content of B16-F10 cells (p < 0.01). The results of zebrafish experiments were consistent with those of in vitro experiments and cell biology experiments. The DCFH fluorescence staining results revealed that both ginseng berries were able to significantly reduce the level of reactive oxygen species (ROS) in zebrafish (p < 0.01). Comparison of chemical composition and skin care activities based on RGB and YGB can provide a theoretical basis for the deep development and utilization of ginseng berry resources.

Enhancing the degradation of microplastics through combined KMnO4 oxidation and UV radiation

The pervasive issue of microplastics in aquatic environments presents a formidable challenge to traditional water treatment methodologies, including those utilizing KMnO4. This study pioneers advanced oxidation processes (AOPs) method aimed at improving the degradation of PE microplastics by employing a dual treatment strategy that combines KMnO4 oxidation with UV irradiation. Detailed analysis of the surface modifications and chemical functional groups of the treated PE microplastics revealed the establishment of Mn-O-Mn linkages on their surfaces. Weight reductions of 3.9%, 4.9%, and 7.5% were observed for the KMnO4/UVA, KMnO4/UVB, and KMnO4/UVC treatments over seven days, respectively. The emergence of carboxyl and hydroxyl groups played a crucial role in accelerating the degradation process. Notably, the combined application of UVC rays and KMnO4 resulted in the most effective degradation of PE microplastics observed in our study. The process significantly enhanced the formation of MnO2 particles from KMnO4 oxidation, with concentrations ranging from 0.036 to 0.070 mM for KMnO4/UVA, 0.066–0.097 mM for KMnO4/UVB, and 0.086–0.180 mM for KMnO4/UVC. Furthermore, the influence of varying pH levels, KMnO4 concentrations, and different water sources on the degradation efficacy was investigated. The pivotal role of free radicals and reactive manganese species in promoting the degradation of PE microplastics was identified. A comparative evaluation with treatments solely utilizing KMnO4 or UV light highlighted the enhanced effectiveness of the combined approach, demonstrating its potential as an efficient solution for reducing microplastic contamination in aquatic systems.

Pt-TiO2 Systems for Enhanced Hydrogen Production from Glycerol: Direct vs Sequential Incorporation Through Photodeposition

Pt-TiO2 systems are the most widely used photocatalysts in the production of green hydrogen from glycerol photoreforming. To incorporate metals on the surface of materials, photodeposition is the most used method because it employs mild conditions. However, despite its use, there are some parameters that have not been deeply studied, such as the appropriate metal loading and the method itself, to obtain a better dispersion of Pt. In this work, six Pt-TiO2 catalysts were synthesized by a classical photodeposition method employing UV radiation. The studied Pt wt.% range was 0.15–0.60 wt.%, being incorporated in one step or in subsequent ones. HRTEM analyses showed that both methods allowed a homogeneous distribution of Pt, and in both, the particle size was around 2.3–3.6 nm, increasing with metal loading. The photocatalytic activity of materials was tested in glycerol photoreforming under UV radiation, and the 0.45 wt.% Pt-containing solid that had been synthesized in one step was the one that allowed the highest hydrogen production. This might suggest that around 0.40% is the appropriate metal loading for hydrogen production under these conditions and that incorporating the desired metal percentage in one step is the most efficient method in terms of energy and time savings.

Mesenchymal stromal cells-derived small extracellular vesicles protect against UV-induced photoaging via regulating pregnancy zone protein.

Ultraviolet (UV) radiation is the primary extrinsic factor in skin aging, contributing to skin photoaging, actinic keratosis (AK), and even squamous cell carcinoma (SCC). Currently, the beneficial role of mesenchymal stromal cell-derived small extracellular vesicles (MSC-sEVs) in cutaneous wound healing has been widely reported, but the field of photoaging remains to be explored. Our results suggested that human umbilical cord MSC-derived sEVs (hucMSC-sEVs) intervention could effectively alleviate skin photoaging phenotypes in vivo and in vitro, including ameliorating UV-induced histopathological changes in the skin and inhibiting oxidative stress and collagen degradation in dermal fibroblasts (DFs). Mechanistically, pretreatment with hucMSC-sEVs reversed UVA-induced down-regulation of pregnancy zone protein (PZP) in DFs, and achieved photoprotection by inhibiting matrix metalloproteinase-1 (MMP-1) expression and reducing DNA damage. Clinically, a significant decrease in PZP in AK and SCC in situ samples was observed, while a rebound appeared in the invasive SCC samples. Collectively, our findings reveal the effective role of hucMSC-sEVs in regulating PZP to combat photoaging and provide new pre-clinical evidence for the potential development of hucMSC-sEVs as an effective skin photoprotective agent.

Environmental characterization and impact of climatic fluctuations on the diversity of extremophilic bacterial communities of a high-altitude seasonal meltwater pond on Ojos del Salado (Dry Andes, Chile)

Earth has unique environments where only microorganisms adapted to extreme conditions can survive. The focus of this study was a high-altitude seasonal meltwater pond on the Altiplano plateau at 5900 m (Dry Andes). The polyextremophilic bacteria of this habitat must adapt to a range of extremities, including cold and dry climate, high UV radiation, and low nutrient availability. A macro-scale analysis was performed to characterize the environment using satellite imagery. To study the composition of bacterial communities, samples were taken from permafrost, water, and sediment of a meltwater pond during three subsequent expedition years under different weather conditions (average, high precipitation, severe drought). The bacterial diversity of the samples was revealed by Illumina MiSeq 16S rRNA gene amplicon sequencing. The results showed that the relative abundance of dominant phyla, such as Pseudomonadota, Bacteroidota, Acidobacteriota, and Verrucomicrobiota varied according to sample types and weather conditions, supported by the satellite environmental state analysis that showed correlations between the availability of snow, water surfaces, and the corresponding surface temperature values. Strong moisture-dependent quantitative changes were detected in the phyla Cyanobacteriota and Actinomycetota. Predominant sequences were linked to orders Chitinophagales, Burkholderiales, Flavobacteriales, and Sphingomonadales, known for their ability to degrade various organic compounds.

Microstructural and mechanical properties of high-strength geopolymer based on Martian soil simulant

Geopolymers made from simulated Martian regolith would suffer from exhibit poor engineering properties, rendering them unsuitable as base materials. To improve the mechanical properties of geopolymers, this study prepared a new Martian soil simulant named DH-1. DH-1- based geopolymers were synthesized using Al2O3 (Al group) and metakaolin (MK group) as modifying agents. The durability of geopolymers with ultraviolet (UV) radiation was assessed under simulated Martian atmospheric conditions. The results indicated that the UCS and FS of both the Al and MK groups increased with curing time, with maximum UCS and FS of 55.27 MPa and 15.16 MPa, respectively. The UCS and FS of the Al and MK groups exhibited a two-phase change. The inflection points for rapid to slow in the UCS and FS occurred on day 28 for the Al group and day 14 for the MK group. The addition of Al2O3 and metakaolin promoted the replacement of silicon atoms by aluminum atoms in the silica-oxygen group, producing more gels product. After UV irradiation, the UCS and FS of the geopolymer decreased by 13 % and 44 %, respectively. Furthermore, the geopolymers underwent carbonation, with new cracks forming due to the combined effects of UV exposure, causing strength reduction.

Single-photon and multi-photon Fano lines for helium and neon using tRecX-haCC

Abstract Single-photon and multi-photon ionization of helium and neon atoms by ultrashort extreme ultraviolet radiation is studied. The wavelength of radiation is chosen to excite a set of doubly excited states. We analyse the lineshapes arising from the presence of doubly excited states and numerically demonstrate the sensitivity of the Fano q parameter to the order of multi-photon process. The computations were performed using the tRecX-haCC package developed by the authors. The tRecX-haCC package solves the time-dependent Schrödinger equation in the presence of a laser pulse and computes the photoelectron spectra including the narrow resonance peaks using the time-dependent surface flux method (tSurff) and iSurf techniques.

Temperature and ultraviolet radiation on a high mountain daphnid: When do interactions become lethal to highly adapted populations?

ABSTRACT Aquatic organisms from high mountain lakes experience extreme influences of climate and solar radiation, especially ultraviolet radiation (UVR), manifested through alterations in physiology, life history, and phenology. Zooplankton, a pivotal component of lake ecosystems, is particularly sensitive to changes in environmental conditions because of their short life cycles and diminished mobility. In the high mountains of the tropical Andes, zooplankton populations are adapted to low temperatures and high UVR because most of the Andean lakes are >4000 m a.s.l. This study focuses on Daphnia pulicaria populations originating from high-mountain Andean lakes, investigating their responses to different temperatures and UVR exposure by means of lab experiments. Key findings indicate that temperature is the most important factor impacting population variables, with high temperatures and UVR exposure leading to unfavorable population outcomes; however, physiological variables (cell viability and pigmentation, measured as melanin) are similarly influenced by temperature and UVR exposure. Pigmentation increases with temperature and is accentuated by solar radiation, indicating an adaptive response to mitigate UVR damage. Conversely, cellular viability declines with elevated temperatures and UVR exposure, showing that higher temperatures may offset the protective effects of pigmentation. Overall, these findings underscore the vulnerability of daphnid populations in high-mountain Andean systems to anticipated climate change impacts, with potential consequences for ecological dynamics in these critical ecosystems. More importantly, they show the importance of studying temperature and UVR (and probably other environmental conditions) as interacting variables because the results will dramatically differ if each factor is considered separately.

Metabolite phosphatase from anhydrobiotic tardigrades.

Terrestrial organisms have systems to escape from desiccation stresses. For example, tardigrades (also known as water bears) can survive severe dried and other extreme environments by anhydrobiosis. Although their extraordinary ability has enchanted people, little is known about the detailed molecular mechanisms of anhydrobiosis. Here, we focused on the tardigrade Ramazzottius varieornatus, one of the toughest animals on Earth. A transcriptome database of R. varieornatus shows that genes encoding a Ferritin-like protein are upregulated during desiccation or ultraviolet radiation. This protein shows sequence similarity to enigmatic proteins in desiccation-tolerant bacteria and plants, which are hypothesized to be desiccation-related. However, because these proteins lack detailed biological information, their functions are relatively unknown. We determined an atomic (1.05 Å) resolution crystal structure of a Ferritin-like protein from R. varieornatus. The structure revealed a dinuclear metal binding site, and we showed that this Ferritin-like protein has phosphatase activity toward several metabolite compounds including unusual nucleotide phosphates produced by oxidative or radiation damage. We also found that a homologous protein from a desiccation- and ultraviolet-tolerant bacterium Deinococcus radiodurans is a metabolite phosphatase. Our results indicate that through cleaning up damaged metabolites or regulation of metabolite levels, this phosphatase family can contribute to stress tolerances. This study provides a clue to one of the universal molecular bases of desiccation-stress tolerance.