Influence Of Ultraviolet Radiation Research Articles

Effects of ultraviolet radiation and reactive oxygen species on the structure and ligand-binding ability of human serum albumin for norfloxacin

To explore the influence of ultraviolet radiation (UV) and reactive oxygen species (ROS) on the structure and ligand-binding ability of human serum albumin (HSA) for norfloxacin (NFLX), HSA was treated with UV (HSAUV) and UV/H2O2 (HSAUV/H2O2), respectively. The structure difference of HSA, HSAUV and HSAUV/H2O2 were investigated by Fourier transform infrared, fluorescence (i.e., emission fluorescence, synchronous fluorescence and fluorescence lifetime) and circular dichroism spectroscopy. The intermolecular interactions of HSA, HSAUV and HSAUV/H2O2 with NFLX were studied at pH 7.4 and temperatures 291, 310, and 318 K, using fluorescence emission and synchronous fluorescence spectroscopy, and combined with molecular docking. The results suggested that UV and ROS could destroy the α-helix of HSA and induce the loose of HSA structure, and the average fluorescence lifetimes of HSA decreased from 6.12 ns to 3.76 ns (HSAUV) and 3.40 ns (HSAUV/H2O2). The conformational changes of HSA caused by UV and ROS allowed NFLX to get access to more potential binding sites and promoted the binding affinity of HSA for NFLX, while the temperature stability of the HSA-NFLX complex significantly decreased. The results are useful and valuable for evaluating the protein damage caused by UV and ROS in organisms.

The influence of UV radiation on the properties of GFRP laminates in underwater conditions

Degradation of polymer composites is a significant problem in many engineering aspects. Due to the interaction of various degradation factors during the exploitation of composites, a synergistic effect of destruction is observed. The article describes the phenomena occurring in glass fiber reinforced polyester laminates under the influence of ultraviolet radiation (UV) in an aquatic environment. The laminates were exposed to UV-A, UV-B and UV-C radiation for 1000 h in free-air and underwater conditions. During the test, the materials were immersed at stable depth of 1 mm and 10 mm, respectively. The three-point bending tests performed on the samples after being exposed to UV showed an increase in the flexural strength of the composites. Simultaneously, degradation of the outer surface layer was observed. The degradation removed the thin resin film from the surface which resulted in a direct exposure of the reinforcing fibers to the environment. The transformations taking place in the deeper layers of the composite increased the mechanical strength due to the additional cross-linking reactions excited by the energy arising from the radiation. Moreover, the formation of polymer structures from free styrene remaining after the technological process and the occurrence of free radical reactions as a result of the cage effect was also observed.

Influence of ultraviolet radiation on insulation properties of silicone rubber for cable accessories and mechanism analysis

Influence of ultraviolet radiation on insulation properties of silicone rubber for cable accessories and mechanism analysis

Retraction Note: The influence of ultraviolet radiations on some rat’s tissues

Retraction Note: The influence of ultraviolet radiations on some rat’s tissues

Study of the Influence of Ultraviolet Radiation as an Aging Intensificant on the Rubber Products Operated in the Agricultural Complex

The factors reducing the safety and operational potential of the metal stock of agricultural machinery are considered. It has been established that the condition of rubber products has a significant influence on it. It is assumed that exposure to ultraviolet radiation is the most representative critical factor for the physical and mechanical properties of rubber products. The methodology for experimental research has been developed, as well as a software interpretation system based on the Matlab libraries.

Some features of trichlorobiphenyls photolysis

The photolytic decomposition of the Trikhlorbifenil mixture, 2,4,5- and 2,4,6-trichlorobiphenyls under an influence of ultraviolet radiation in presence of tungsten oxide as a catalyst in a methanol medium was studied. A higher rate of photolysis of individual congeners of polychlorbiphenyls was established compared to the congeners of the Trikhlorbifenil mixture. The influence of structural features of polychlorarenes on a depth of photodecomposition and a routes of formation of photodestruction products was considered.

UV Radiation Effect in New Materials Developed for the Construction of Beehives.

In recent decades, there has been an increasing focus on the alarming decline in global bee populations, given their critical ecological contributions to natural pollination and biodiversity. This decline, marked by a substantial reduction in bee colonies in forested areas, has serious implications for sustainable beekeeping practices and poses a broader risk to ecological well-being. Addressing these pressing issues requires innovative solutions, one of which involves the development and fabrication of beehives crafted from composite materials that are ecologically compatible with bee biology. Importantly, these materials should also exhibit a high resistance to environmental factors, such as ultraviolet (UV) radiation, in order to maintain their mechanical integrity and longevity. To investigate this, we conducted accelerated UV degradation tests on a variety of composite materials to rapidly assess their susceptibility to UV-induced changes. High-density polyethylene (HDPE) served as the matrix material and was reinforced with natural fibers, specifically fique fibers (Furcraea bedinghausii), banana fibers, and goose feathers. Our findings indicate that UV radiation exposure results in a noticeable reduction in the tensile strength of these materials. For example, wood composites experienced a 48% decline in tensile strength over a 60-day period, a rate of deterioration notably higher than that of other tested composite materials. Conversely, HDPE composites fortified with banana fibers initially demonstrated tensile strengths exceeding 9 MPa and 10 MPa. Although these values gradually decreased over the observation period, the composites still displayed favorable stress-strain characteristics. This research underscores the substantial influence of UV radiation on the longevity and efficacy of beehive materials, which in turn affects the durability of natural wood hives exposed to these environmental factors. The resultant increased maintenance and replacement costs for beekeepers further emphasize the need for judicious material selection in beehive construction and point to the viability of the composite materials examined in this study.

Vitamin D deficiency and malignancies

The analysis of domestic and foreign literature shows that oncological diseases are most often accompanied by a low level of 25(OH)D in the blood serum of patients and a high prevalence of deficiency and severe deficiency of vitamin D. It can be confidently stated that the level of 25(OH)D in serum blood of oncological patients, on average, is lower than in healthy people of the corresponding sex and age. In this regard, statistical studies were carried out, which demonstrated the prevalence of vitamin D deficiency in the countries of Europe and North America, which is directly proportional to the level of annual mortality from cancer and the probability of death from cancer, any type of cardiovascular disease, diabetes and chronic respiratory diseases, and this relationship is statistically significant (p < 0.001). Oncological morbidity and mortality from cancer in the Russian Federation naturally increases especially in higher latitudes, which, along with other reasons, is associated with a limitation in the duration of the effective production of vitamin D3 in human skin under the influence of ultraviolet radiation. Some clinical studies of vitamin D supplementation as a therapeutic agent are showing measurable positive results in cancer, with far more positive than in placebo groups. However, negative results that are harmful to patients participating in clinical experiments have not been established in the study of many hundreds of studied articles on this issue. The most commonly seen beneficial effects of vitamin D supplementation have been in the treatment of breast and colorectal cancer, which are particularly noticeable in patients with low baseline serum levels of 25(OH)D and high daily doses of 25(OH)D3 supplementation well above standard recommendations of 400–800 IU daily. Due to the high prevalence of vitamin D deficiency among cancer patients, taking into account international positive experience, it seems very useful and necessary to create domestic scientific foundations and expand the clinical practice of using vitamin D supplements as a therapeutic agent for cancer.

Encapsulation of α-Lipoic Acid in Halloysite Nanotubes

A nanocomposite material based on halloysite and α-lipoic acid was studied. The kinetics of the degradation process of α-lipoic acid under the influence of ultraviolet radiation and thermal stress in its native state and in the composition of a halloysite-based nanocomposite were studied. The concentration of undegraded α-lipoic acid and the effect of the nanocomposite composition were determined by the HPLC method. It has been shown that adding α-lipoic acid to halloysite using a vacuum method allows for an increase in its resistance toward UV light of 84.4%, and the thermal resistance was also significantly improved. The composite based on halloysite and α-lipoic acid can be used to improve the resistance to photodegradation of pharmaceutical drugs or sunscreen cosmetics because this strategy preserves the biological active properties and shelf life of the α-lipoic acid.

Different UV-B exposure times induce phenotypic, transcriptomic, and proteomic changes in wine grape leaves

The Shangri-La region, located in southwest China, is known for its dry climate and intense UltraViolet (UV) radiation due to its high altitude. Research conducted in the past has demonstrated that UV radiation, particularly UV-B radiation, enhances plants' ability to withstand cold temperatures, diseases, and arid conditions. Indeed, the Cabernet Sauvignon grape variety, predominantly cultivated in Shangri-La where the UV intensity reaches 21–22w/m2, has displayed remarkable resilience in recent decades. However, the specific impact of UV-B radiation on Cabernet Sauvignon grape leaves has yet to be fully understood. Consequently, our objective is to investigate the influence of UV radiation on grapes grown at high altitudes. To gain insights into the short-term effects on grape leaves, we conducted a comprehensive investigation involving anatomical and photosynthetic changes. Additionally, we analyzed the transcriptomic and proteomic regulation associated with these changes following exposure to UV-B radiation at intensities ranging from 15–20w/m2 for durations of 3 and 7 days.The findings of our study demonstrated that exposure to UV-B radiation, particularly at intensities surpassing 10w/m2, led to noticeable changes in the morphology of epidermal and palisade tissue cells. Furthermore, after a 3-day exposure to UV-B, we observed an upregulation of proteins responsible for cytoskeletal organization and cell wall synthesis. Conversely, following a 7-day treatment, proteins associated with disease resistance and antioxidants showed increased expression. Transcriptomic analysis revealed a significant enrichment of proteins and genes linked to pathogen infection, defense mechanisms, and antioxidant processes. Overall, our research highlighted the positive impact of intense UV radiation at high altitudes on enhancing disease resistance and environmental adaptability in Cabernet Sauvignon grape plants.

Research on thermal stress fracture performance of low-temperature asphalt concrete in castel high altitude area

The temperature in the southwest Castel highland area is relatively low, and the asphalt concrete on the road surface is in a low-temperature state all year round. Strong ultraviolet radiation will interfere with the material and cause it to fracture and damage. This paper uses a low-temperature bending test and thermal stress constrained specimen test (TSRST) to test the low-temperature performance of asphalt mixtures with different gradation and asphalt types under different ultraviolet (UV) aging conditions. Existing studies are mainly based on asphalt aging, which cannot take into account the interactions between the binder and aggregate phases during aging. This paper analyzes the correlation between test indexes after UV aging and asphalt mixture parameters, as well as the impact of UV on asphalt mixtures, and the mechanical strength prediction model was established. The results indicate that when the aging time is less than 2 months, the low-temperature performance degradation rate of the asphalt mixture first accelerates and then gradually slows down. The degree of influence of ultraviolet radiation on different graded asphalt mixtures is in descending order: stone asphalt concrete, AC 16 asphalt concrete, and AC-13 asphalt concrete. The relationship between fracture thermal stress and asphalt mixture parameters is strong. It is suggested that the appropriate equivalent outdoor aging time is 2 months in the low-temperature performance test of asphalt mixture after UV aging. At the point when there is no UV test condition, the worth acquired by the test is prescribed to consider the UV aging attenuation coefficient, and the matrix asphalt can allude to 0.84; modified asphalt has a value of 0.9. This article is of great significance for guiding the research on thermal stress fracture of low-temperature asphalt concrete in Castel high-altitude areas.

Chronic exposure to UVB induces nephritis and gut microbiota dysbiosis in mice based on the integration of renal transcriptome profiles and 16S rRNA sequencing data

Ultraviolet (UV) is a common and abundant environmental factor that affects daily life. Although the effects of UV radiation on the skin have been extensively reported, studies on the influence of UV radiation on internal organs are still limited. This study aimed to evaluate the influence of UVB exposure on the kidney of mice and to investigate the possible mechanism. In the present study, histopathology changes, oxidative stress, and inflammatory response were used to evaluate the kidney and colon injury induced by UVB exposure. The results showed that the 14-week chronic skin exposure to UVB triggers a kidney injury response characterized by macrophage infiltration, elevated oxidative stress as well as inflammatory and injury markers. The RNA sequencing demonstrated that chronic UVB exposure could alter the kidney transcriptomic profile distinguished by the regulation of genes involved in the Notch signaling pathway, JAK-STAT signaling pathway, and ECM-receptor interaction. Besides, chronic UVB exposure also resulted in gut dysbiosis, manifested as colon macrophage infiltration, stimulated inflammatory responses, impaired barrier integrity, and microbiota structural and functional disorders. The Spearman analysis results further revealed a strong correlation between gut microbiota and kidney injury. In conclusion, skin chronic exposure to UVB causes nephritis and gut microbiota dysbiosis in mice, and these findings provide new insight into the underlying risks of chronic UVB exposure to human wellness.

Influence of whitening additives on the properties of decorative slag-alkali cements and mortars

The paper shows a comparative study of the influence of whitening additives (kaolin, TiO2 and СаСО3) on the production of decorative alkali-activated slag cement and mortars with a degree of whiteness of at least 70%; as well as their influence on the structure formation and evolution of physico-mechanical properties. According to results obtained, kaolin provides chemical bonding of Na+ into insoluble zeolite-like compounds; and CaCO3 densifies the structure and reduces shrinkage deformations. At the early stages of hardening (up to 7 days), the additions of kaolin and calcite, due to their significant amount (15 and 24%), reduces the compressive strength of the cement paste; nevertheless, at later ages (until 90 days) the difference in strength almost disappears. The high colourfastness and weather resistance of pigmented cements under the influence of ultraviolet radiation and freeze/thaw cycles has been established. A comparative assessment of the economic efficiency has shown that СаСО3 is the best cost-effective additive.

Study on Electrophysical Properties in KMnO4-Doped Grade "Xorazm-150" Cotton Fibers

The main objective of the research was to identify the semiconducting characteristics of mature medium-thick (diameter 14, 15 µm) "Xorazm-150" cotton fibers both undoped and doped with 1.5% aqueous solution of KMnO4, including current versus voltage and temperature dependence, temperature dependence of electrical conductivity, the influence of doping time on conductivity, and photoconductivity. The research was conducted in the temperature range (296-360 K) and the voltage range (0-100 V). The infrared spectra of the undoped and KMnO4-doped samples were studied (Both samples were mercilized with NaOH). It was found that the cotton fibers sample doped with KMnO4 had considerably higher electrical conductivity than the undoped sample. It was determined that the cotton fibers sample doped with KMnO4 obeys the law of Ohm when current flows through it. Also, it was analyzed that the formation of photoconductivity of the cotton fibers sample doped with KMnO4 under the influence of ultraviolet radiation indicates that the photoconductivity is mainly related to the formation of band electron-hole pairs. The deep surface created by doping cotton fibers with a 1.5% solution of KMnO4 in water was found to have an activation energy that was determined from the results.

Influence of ultraviolet radiation on sowing qualities of the cucumber family of the “Murashka” varieties

Increasing the productivity of crops, preliminary stimulation of seeds. One of the effective physical methods of pre-sowing stimulation is the treatment of seeds with solar ultraviolet radiation A and B. The article examines the results of research studies measuring the density of germination energy and the similarity of the “Murashka” variety cucumber seeds. The analysis of dependences, and incomes according to the research results, allows the maximum values of germination energy and germination of cucumber seeds are 190 – 210 J/m2.

Study of the Influence of the Additive "Polymateria" on the Ability to Biodegrade Polyethylene Films

Introduction. The article is devoted to the study of the influence of the "Polymateria" additive on the properties of polyethylene films and their biodegradability. The additive "Polymateria" is presented by the manufacturer as an additive that accelerates the process of biodegradation of polyolefin films. However, studies published in the literature have not previously been presented.Purpose. Therefore, the purpose of the work is to study polymer films containing the Polymater additive for their performance characteristics and evaluate film samples for biodegradability. In the work, polymer films based on polyethylene and the additive "Polymateria" were obtained by extrusion.Materials and Methods. The following research methods were used in the work: a method for determining water absorption, a method for determining resistance to chemical media, a method for artificial aging of polymeric materials under the influence of ultraviolet radiation and temperature, a uniaxial tensile test method, comprehensive studies of films for biodegradation by composting, determination of the sanitary and hygienic properties of experimental samples during exposure in simulation environmentsResults. In the course of the study, it was found that the physical and mechanical properties under the influence of UV irradiation do not change as intensively as compared with the deformation-strength characteristics of samples that were subjected to artificial aging at temperature. It has been established that within 28 hours of exposure to thermal-oxidative aging, polyethylene films are destroyed and lose their integrity. It has been established that within 28 hours of exposure to thermal-oxidative aging, polyethylene films are destroyed and lose their integrity.In the process of composting, the relative elongation at break of samples treated with UV decreases by 1.5-2 times compared to the values ​​before composting. When composted for 7 months, the samples did not change their size, and their weight did not change either.Conclusion. Studies by the sanitary-chemical method made it possible to determine that in the environment of sodium chloride and distilled water after three weeks of exposure to polyethylene films containing the additive, a pungent odor is determined that exceeds the criterion of 2 points. Thus, such films cannot be used for food contact.

Preparation, structure and photocatalytic activity of nanocomposites based on cerium oxide

Mesoporous CeO2 and MgO powders and nanocomposites based on them were synthesized by the method of self-propagating high-temperature synthesis, and the mutual influence of magnesium oxide and cerium oxide on the crystal structure, microstructure, and morphology of the obtained materials was studied. It has been established that CeO2 is formed on the surface of magnesium oxide, while the developed surface of the material is preserved. It has been established, that the sizes of CeO2 crystallites in the composition of nanocomposites change insignificantly and range from 6.5 to 7.4 nm, while the values of the specific surface area and average pore diameter of the studied samples depend on the composition and vary in the ranges of 19–41 m2/g and 11.9‒19 nm, respectively. The highest efficiency of photodegradation of dyes of acid telon blue and direct bright blue is observed for samples of MgO–CeO2 (30 mol.%) and MgO–CeO2 (50 mol.%) ‒ 98.5 and 92.5 %, respectively, taking into account the effect of direct photolytic decomposition under the influence of ultraviolet radiation.

Perspective on the influence of ultraviolet radiations in plant growth and development

Accumulating evidence points to the multidimensional role of ultraviolet radiation in plant growth and development. Ultraviolet-A (UV-A), as the main component of UV radiation in nature, has a wide range of effects on plants. As there is some evidence of its positive effect as a regulator of plant growth in a controlled environment, there has long been interest in the use of UV-A in agriculture. However, the role of UV-A in plant growth remains largely unknown and the number of studies looking at the effects of UV-A in a controlled environment is still too small. The review carried out here also includes the effects of other UV components on plant growth, morphology and physiology, such as: UV-B, as well as the interplay of other abiotic stresses and UV-A as growth regulators. On the basis of the synthesis presented here, it can be concluded e.g. that lower doses of UV-A radiation can stimulate the growth of plant in a controlled environment. Perhaps it will soon contribute to the optimization of indoor plant growing recipes.

Influence of UV Radiation on Mechanical Properties of Polymer Optical Fibers.

This paper presents an analysis of the mechanical properties of different polymer optical fibers (POFs) at ultraviolet (UV) radiation conditions. Cyclic transparent optical polymer (CYTOP) and polymethyl methacrylate (PMMA) optical fibers are used in these analyses. In this case, the fiber samples are irradiated at the same wavelength, pulse time and energy conditions for different times, namely, 10 s, 1 min, 2 min and 3 min. The samples are tested in tensile tests and dynamic mechanical thermal analysis (DMTA) to infer the variation in the static and dynamic properties of such fibers as a function of the UV radiation condition. Furthermore, reference samples of each fiber (without UV radiation) are tested for comparison purposes. The results show a lower UV resistance of PMMA fibers, i.e., higher variation in the material features in static conditions (Young's modulus variation of 0.65 GPa). In addition, CYTOP fiber (material known for its high UV resistance related to its optical properties) also presented Young's modulus variation of around 0.38 GPa. The reason for this reduction in the moduli is related to possible localized annealing due to thermal effects when the fibers are subjected to UV radiation. The dynamic results also indicated a higher variation in the PMMA fibers storage modulus, which is around 30% higher than the variations in the CYTOP fibers when different radiation conditions are analyzed. However, CYTOP fibers show a smaller operational temperature range and higher variation in the storage modulus as a function of the temperature when compared with PMMA fibers. In contrast, PMMA fibers show higher variations in their material properties when subjected to oscillatory loads at different frequency conditions. Thus, the results obtained in this work can be used as guidelines for the influence of UV radiation in POFs not only for the material choice, but also on the limitations of UV radiation in the fabrication of the grating as well as in sensor applications at UV radiation conditions.

Laser induced thermotherapy of multiple actinic keratosis

Actinic keratosis (AK) is one of the most common precancerous diseases of the skin, which is characterized by local intraepidermal atypia of keratinocytes that occurs under the influence of ultraviolet radiation, clinically manifested by typical foci of hyperkeratosis in exposed areas of the skin. This is an urgent medical and social problem due to the potential tendency of atypical keratinocytes to malignant transformation, proliferation of keratinocytes and their spread beyond the epidermis with the development of tumor progression [1]. Recently, a number of authors have established important features of the course of this precancerous tumor. First of all, we are talking about an increased risk of malignant transformation of AK into squamous cell carcinoma in the presence of a history of visceral malignancy, as well as the same changes in the lesion and the adjacent clinically unaffected skin in the form of accumulation of genetic and epigenetic mutations that form "cancerization fields" [ 33,34], indicating the need to treat AK, especially multiple foci, using the ablastic rule with the capture of 1-1.5 cm of apparently healthy skin [35,36]. For the treatment of multiple AK foci in a patient with an aggravated oncological history, for the first time, we used, in an independent version, a modern method of treatment - laser-induced thermotherapy (LITT). LITT is a non-invasive, antitumor, immunomodulatory method based on the selective death of atypical keratinocytes in the epidermis by local tissue heating to a temperature of 42.5-44℃ (hyperthermia) caused by infrared laser radiation with a wavelength of 800-1300 nm. The presented case of AK in a patient with breast cancer in history was characterized by a combination of keratotic and erythematous forms of the tumor. At the same time, LITT with an extended exposure zone by 1 cm from the visible boundaries of the lesions was not only clinically effective in terms of immediate and long-term results, but also gave an excellent cosmetic result with a completely satisfactory tolerability of the treatment procedure.