Effects Of Ultraviolet Radiation Research Articles

SOSIALISASI PENGGUNAAN TABIR SURYA PADA SISWA SDN 2 TERONG TAWAH SEBAGAI UPAYA MENCEGAH DAMPAK NEGATIF SINAR UV

Indonesia is a tropical country with prolonged exposure to sunlight. The sun emits UV rays, and prolonged exposure to these rays can lead to various health issues such as sunburn, premature aging, tanning, erythema formation, and ultimately, skin cancer. Preventing the negative effects of UV radiation is crucial, especially for children who often engage in outdoor activities. The aim of this initiative is to enhance children's awareness of the dangers of excessive UV exposure to health and educate them on preventive measures, thereby improving the overall health quality of the community, particularly among children. The method employed in this activity includes a series of events: opening, pretest to assess participants' understanding before receiving information, delivering the material to enhance participants' knowledge, discussion, posttest to evaluate participants' understanding after the material presentation, and closure. Based on the pretest-posttest results, the average pretest score was 39.09 ± 19.001, with the lowest score at 00.00 and the highest at 60.00. The average posttest score was 66.36 ± 20.83, with the lowest at 20.00 and the highest at 100.00. Statistical analysis indicates a significant improvement in the average pretest and posttest scores (p<0.05), demonstrating an increase in participants' knowledge before and after receiving the material. These findings suggest that the awareness campaign has effectively increased the participants' knowledge regarding the dangers of excessive UV exposure to health and its preventive measures.

An invitro nevus explant model for studying the effects of ultraviolet radiation.

Ultraviolet radiation (UVR) has been recognized as a potential trigger for the transformation of benign melanocytic nevi into melanoma. However, the mechanisms governing the formation and progression of melanocytic nevi remain poorly understood. This lack of understanding is partly due to the difficulty in isolating and culturing nevus tissues invitro, resulting in a dearth of robust exvivo models for nevi. Therefore, the establishment of a reliable melanocytic nevus model is imperative. Such a model is essential for elucidating nevus pathogenesis and facilitating the development of effective therapeutic interventions. Therefore, we have sought to establish an exvivo nevus explant model to study UVR stimulation. And the structural integrity and tissue activity of the exvivo nevi explant model was evaluated. We then observed melanogenesis and proliferation activity of the explants after UVR stimulation. There was less blister formation after Day 3 in nevi explants under our modified medium conditions. The nevi explant was able to maintain almost the same morphological structure and tissue activity as invivo tissue within 24 h. Following UVR stimulation, we observed increased melanogenesis and proliferation activity in nevi explants. Nevi explants could serve as an exvivo model for UVR-induced nevi stimulation research.

Selection of Native Beauveria bassiana1 Strains for Formulation by Coacervation and the Effect of Temperature and UV Radiation on Their in vitro Stability

Selection of Native Beauveria bassiana1 Strains for Formulation by Coacervation and the Effect of Temperature and UV Radiation on Their in vitro Stability

An investigation into the effect of UV irradiation and biofilm colonization on adsorption and desorption behavior of polyurethane (PU) microplastics for bisphenol A (BPA)

Recent studies have demonstrated that microplastics (MPs) can act as a transport vector for pollutants in the environment. However, most studies have focused on carbon-carbon backbone polymers, with little known about heteroatom backbone polymers. In this study, polyurethane (PU) MPs were modified by UV irradiation and microorganism colonization to assess the different aging treatments on the interaction behavior (adsorption/desorption) between PU MPs and bisphenol A (BPA). The results of the adsorption kinetics experiment illustrated that the adsorption process of BPA could be described well by a pseudo-second order kinetic equation on both fresh and aged PU MPs. Although fresh PU MPs revealed the highest saturated adsorption capacity, at low BPA exposure concentrations (≤ 100 μg/L) the adsorption capacities for UV aged and biofilm colonized PU MPs were very similar to fresh MPs or even slightly higher than for fresh MPs, the main adsorption mechanisms including H-bonding interactions and π–π interactions. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) investigations suggested obvious physicochemical property changes (e.g., generation of new functional groups, erosion, etc.) after UV irradiation and biofilm colonization. This study also showed that different exposure environments (ultrapure water, artificial seawater, simulated gastric fluid) could affect BPA adsorption/desorption via hydrophobic and electrostatic interaction on PU surfaces. These results further clarify the adsorption mechanisms of BPA on PU MPs that have undergone different aging treatments, and provides a theoretical basis for the assessment of environmental behavior and exposure risks when PU MPs and BPA coexist.

UV-Radiation and TiO2 Nanoparticles Effects on Physical Properties of PVA/CMC/TiO2 Nanocomposite Films

Fabrication of nanocomposite films of polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blended with Titanium dioxide nanoparticles (TiO2 NPs) by a modest solution casting technique is investigated. Also, TiO2 NPs and UV-irradiation effects for different intervals (12, 26, 40, and 48 hours) on the morphology (FESEM), structure (XRD), composition (FTIR) and optical properties (UV-Vis) of as-prepared films are inspected. FESEM images display that the morphology of PVA/CMC/TiO2 nanocomposite films is altered due to the strong influence of TiO2 NPs and UV exposure. The XRD spectra indicate that the amorphous phase of the samples has changed (decline or enhancement) due to UV exposure. The FTIR spectra demonstrate that the UV-irradiation period had a favourable impact on polymer structure by exhibiting some interesting IR peaks. Furthermore, the UV-Vis examination illustrates that the increased UV-irradiation times (12 h to 40 h) and TiO2 NPs addition improved the absorption intensity of the as-prepared films. Interestingly, the Energy gap Eg of the nanocomposite films was tuned from 4.47 eV to 5.01 eV with increased irradiation time (12 h to 40 h). In contrast, due to a higher increased UV-irradiation time of 48 h, the Energy gap Eg value of nanocomposite film was decreased to 4.62 eV. That can be attributed to the strong effect of UV exposure, which influenced the creation of structural defects. Finally, these findings prove that the PVA/CMC/TiO2 nanocomposite films have an amazing chance to be used in important optoelectronic applications.

Preparation of Yellowing-Resistant Waterborne Polyurethane Modified with Disulfide Bonds.

Waterborne polyurethane, renowned for its lightweight properties, excellent insulation capabilities, and corrosion resistance, has found extensive application in fields such as construction, automotive, leather, and thermal insulation. Nevertheless, during operational usage, waterborne polyurethane materials, akin to other polymeric substances, are susceptible to oxidative aging manifestations like yellowing, cracking, and diminished mechanical performance, significantly curtailing their utility. Consequently, the synthesis of yellowing-resistant polyurethane assumes pivotal significance. This study integrates dynamic reversible reactions into the synthesis process of polyurethane by introducing the dynamic reversible compound 2-hydroxyethyl disulfide as a chain extender, alongside the incorporation of a UV absorber to enhance the polyurethane's resistance to yellowing. When the disulfide bonds absorb heat, they undergo cleavage, yielding thiols that spontaneously recombine into disulfide bonds at ambient temperatures, allowing for the continuous breaking and reformation of disulfide bonds to absorb heat. Concurrently, in collaboration with the UV absorber, the detrimental effects of ultraviolet radiation on the polyurethane material are mitigated, thereby augmenting its resistance to yellowing. This study scrutinizes the positioning of UV absorber addition, the quantity of UV absorber, and the molar ratio of 1,4-butanediol to 2-hydroxyethyl disulfide, characterizing the functional groups of polyurethane through infrared and Raman spectroscopy. It is observed that the successful preparation of yellowing-resistant polyurethane is achieved, and evaluations on the modified polyurethane through color difference, tensile, and centrifugal tests reveal that the optimal yellowing resistance is attained by adding a UV absorber at a mass fraction of 1% to 3% prior to chain extension, resulting in a color change grade of 2, denoting slight discoloration. Simultaneously, the other properties of polyurethane exhibit relative stability. Notably, when the molar ratio of 1,4-butanediol to 2-hydroxyethyl disulfide is 3:2, the overall performance of the polyurethane remains stable, with exceptional yellowing resistance capabilities attaining a color change grade of 2.

Quantitative analysis of body colouration in Sebastes rockfishes

Body colouration, a trait under strong selection, is influenced by the visual background of the environment. The stable influence of depth on visual background dynamics is due to light attenuation along the water column. Depth is also a key factor driving diversification in Sebastes rockfishes, influencing variations in several biological traits. Comparisons between closely related species suggest that brightly coloured species (red, orange, or yellow) tend to inhabit deeper waters and have slower growth rates compared to their shallow-water counterparts with dominance of dark colours (black, brown, or grey). Here, we used 377 photos from 100 Sebastes species, along with recently developed methods of colour quantification and phylogenetic comparative analyses, to assess this trend. Our analyses confirmed the separation of body colouration regarding depth, which was accompanied by differences in growth rates and morphological traits. This indicated that variations in body colourations are included in the ongoing correlational selection process dictated by depth. Analyses of closely related species indicated that depth is an initial driver of colour differentiation and that colour differences do not progressively increase with genetic divergences. We hypothesized that the bright-coloured rockfishes are found in deeper waters because in shallow environments they are more vulnerable to the potential negative effects of UV radiation and higher predation risk, while their predation successes are lessened, in comparison to dark-coloured rockfishes. Overall, this study emphasizes the intricate relationship between genetics, environment, adaptation, and the striking diversity of body colourations observed in Sebastes rockfishes.

Extraction and antioxidant capacity of mycosporine-like amino acids from red algae in Japan.

Mycosporine-like amino acids (MAAs) are the natural UV absorbing compounds with antioxidant activity found in microalgae and macroalgae. We collected red algae Asparagopsis taxiformis, Meristotheca japonica, and Polysiphonia senticulosa from Nagasaki, where UV radiation is more intense than in Hokkaido, and investigated the effect of UV radiation on MAAs content. It was suggested that A. taxiformis and M. japonica contained shinorine and palythine, while UV absorbing compound in P. senticulosa could not be identified. The amounts of these MAAs were lower compared to those from Hokkaido. Despite an increase in UV radiation in both region from February to April, MAAs contents of red algae from Nagasaki slightly decreased, while that from Hokkaido significantly decreased. This difference was suggested the amount of inorganic nitrogen in the ocean. Antioxidant activity of MAAs increased under alkaline conditions. The extract containing MAAs from P. senticulosa showed the highest antioxidant activity among four red algae.

Enhancing Escherichia coli Inactivation: Synergistic Mechanism of Ultraviolet Light and High-Voltage Electric Field.

This study investigated the bactericidal effects of ultraviolet (UV) radiation, a high-voltage electric field (HVEF), and their combination on Escherichia coli. The results indicated that UV and combined disinfection were more effective with longer exposure, leading to significant reductions in microbial activity. Specifically, the single UV disinfection alone reduced activity by 3.3 log after 5 min, while combined disinfection achieved a 4.2 log reduction. In contrast, short-term HVEF treatment did not exhibit significant bactericidal effects, only achieving a reduction of 0.17 log in 5 min. Furthermore, prolonged exposure to both UV disinfection and an HVEF was found to damage cell membranes, ultimately causing cell death, while shorter durations did not. Despite rapid cell count decreases, flow cytometry did not detect apoptotic or necrotic cells, likely due to rapid cell rupture. This study suggests that combining UV radiation and an HVEF could be a promising approach for inhibiting bacterial reproduction, with HVEF enhancing UV effects. These findings provide insights for using combined HVEF and UV disinfection in food safety and preservation.

Exploring the effects of ultraviolet radiation on the properties of Fe3O4/PANI nanostructures

The properties of any material are the basis for the most diverse applications of science, which allows for the dazzling development of new technologies. In this work, we present a new method of synthesis of Fe3O4/PANI nanostructures using ultraviolet radiation. We show that the nanostructures produced by our method have exceptional properties, evidenced by the high stability and quality of the nanostructures. Among the highly stable properties, the magnetic ones stand out, where the nanostructures have high coercivity and remanence, in addition to a well-defined saturation magnetization. Such characteristics of this type from nanostructure indicate the method is promising for producing thin films with high stability and excellent magnetic and conductive properties.

Boosting Efficiency and UV Resistance in Perovskite Solar Cells via Sunscreen Ingredient Octinoxate

AbstractUV radiation presents a substantial challenge to the stability of perovskite solar cells (PSCs), limiting their applications in harsh environments such as outer space. Herein, UV‐resistant molecule octinoxate (OCT) is introduced to mitigate the adverse effects of UV irradiation. OCT additive demonstrates the capability to modulate the crystallization process, resulting in perovskite films with larger grains and enhanced crystallinity. Moreover, OCT doping also facilitates charge extraction in PSCs. The PSCs with OCT doping exhibit an enhanced efficiency, increasing from 22.46% to 24.64%, along with improved stability with a T85 of 1000 h under continuous light exposure. Functioning as a sunscreen material, OCT mitigates UV‐induced degradation by absorbing irradiation and hindering I2 escape. Even after continuous exposure to 18.7 kWh m−2 UV illumination, the OCT‐doped PSCs maintain over 92% of their initial efficiency, meeting the 15 kWh m−2 UV exposure requirement specified in the IEC:61215 PV robustness testing standard. This study offers a straightforward approach to enhance the durability of PSCs under UV radiation, opening avenues for their application in extreme environments.

UV‐Induced Oxidation Preparation of Multi‐Functional Lignin‐Based AgNPs and its Application for Conductive Coating, Antibacterial Enhancement, and Product Separation

AbstractThis study presents a novel approach for regulating the properties of lignin‐based silver nanoparticles (AgNPs), which was UV‐induced Tetrahydrofuran (THF) to form peroxide for the etching of these nanoparticles. The lignin coating was first degraded by oxidation, and the properties of the exposed AgNPs changed under etching. Notably, water can greatly regulate the oxidation capacity of the THF medium, thereby controlling the degradation degree of lignin coating and obtaining dissolution, aggregation, precipitation, and color‐variable phenomena of AgNPs under the synergistic effect of UV irradiation and peroxide etching. By adjusting UV irradiation time, various functional products of silver nanowires (AgNWs), color‐variable AgNPs, lignin‐based AgNPs aggregates, and composite solution of Ag particles and Ag+ were obtained. The transformation of these product properties is closely related to the oxidation capacity of H2O/THF medium. In addition, Multi‐functional Lignin‐based AgNPs show excellent application potential in conductive coating, antibacterial enhancement, and product separation, providing a promising avenue for the targeted utilization of lignin‐based AgNPs.

Effect of UV radiation on the high temperature and fatigue performance of SBS modified asphalt and asphalt mixture

In this study, the effects of UV radiation on the high temperature fatigue performance of SBS modified asphalt and asphalt mixtures were analyzed, and the effects of outdoor atmospheric UV radiation were simulated by indoor UV accelerated aging test. The results showed that the increase of UV radiation time led to the increase of creep recovery rate of asphalt and the decrease of irrecoverable creep flexibility, i.e., the resistance to permanent high temperature deformation of SBS modified asphalt was improved. The fatigue cracking resistance of asphalt was weakened and accelerated by radiation. UV radiation increased the rutting resistance of asphalt mixtures and weakened the fatigue resistance at high temperatures. At the same time, UV radiation reduced the aromatic and saturated content of SBS modified asphalt, which led to a reduction in the relative aromatic and saturated content of asphalt mixtures.

Changes in antioxidant properties of pepper leaves (Capsicum annuum L.) upon UV radiation

Bell pepper (Capsicum annuum) is one of the most popular vegetables consumed worldwide. The leaves of pepper are rich in phenolics, including phenolic acids and flavonoids. These compounds are well known for their ultraviolet (UV) absorbing and antioxidant properties. While the change of the phenolic pattern is an intensive research subject, it is not yet well-known in pepper leaves, particularly in outdoor conditions. In this experiment, we examined the effect of UV radiation on the leaves of outdoor grown peppers, focusing on the UV-absorbing properties and antioxidant capacities. Three different total antioxidant capacity (TAC) measurements have been compared: (I) Folin-Ciocalteu Reactivity (FC), (II) Ferric Reducing Antioxidant Power (FRAP) and (III) Trolox Equivalent Antioxidant Capacity (TEAC). Moreover, non-enzymatic hydrogen peroxide scavenging antioxidant capacity was measured. Significant increase was detected only in FRAP, suggesting an elevation exclusively in the level of phenolic acids in case of UV exposed outdoor grown pepper leaves.

Synergistic effects of ultraviolet radiation and corrosion on Zr alloys

Ultraviolet (UV) radiation and corrosion can be coupled in non-trivial ways and such coupling is of critical importance for the performance of materials in extreme environments. However, the confluence of these phenomena and their collective impact remains underexplored. This study bridges this knowledge gap by presenting a thorough investigation of Zr alloys exposed to corrosive high-temperature water under in-situ UV irradiation. We found that initial UV exposure significantly accelerates corrosion and induces distinct changes in the microstructure of ZrO2 oxides. Over time, we observed the formation of Fe3O4 particles on the ZrO2 surface due to photo-dissolution of zirconia and photo-deposition of iron oxide magnetite. The emergence of Fe3O4 particles could enhance the corrosion resistance of the Zr alloy substrate. Furthermore, our results indicate that UV irradiation modulates the density and distribution of nanopores within the oxide layer by influencing oxygen speciation and the dynamics of oxide growth. These insights advance our understanding of the complex interplay between UV irradiation and high-temperature water corrosion.

Type I Diabetes Mellitus Suppresses Experimental Skin Carcinogenesis.

This study explores the previously uncharted territory of the effects of ultraviolet (UV) radiation on diabetic skin, compared to its well-documented impact on normal skin, particularly focusing on carcinogenesis and aging. Employing hairless SKH-hr2, Type 1 and 2 diabetic, and nondiabetic male mice, the research subjected these to UV radiation thrice weekly for eight months. The investigation included comprehensive assessments of photoaging and photocarcinogenesis in diabetic versus normal skin, measuring factors such as hydration, trans-epidermal water loss, elasticity, skin thickness, melanin, sebum content, stratum corneum exfoliation and body weight, alongside photo documentation. Additionally, oxidative stress and the presence of hydrophilic antioxidants (uric acid and glutathione) in the stratum corneum were evaluated. Histopathological examination post-sacrifice provided insights into the morphological changes. Findings reveal that under UV exposure, Type 1 diabetic skin showed heightened dehydration, thinning, and signs of accelerated aging. Remarkably, Type 1 diabetic mice did not develop squamous cell carcinoma or pigmented nevi, contrary to normal and Type 2 diabetic skin. This unexpected resistance to UV-induced skin cancers in Type 1 diabetic skin prompts a crucial need for further research to uncover the underlying mechanisms providing this resistance.

Evaluation of the effect of chemical disinfection and ultraviolet disinfection on the dimensional stability of polyether impression material: an in-vitro study

BackgroundVarious methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods.MethodsThis in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes.ResultsA comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey’s tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes.ConclusionsThis study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.

New trends on personalized sunscreens.

Nowadays, there are emerging trends in customized and personalized photoprotection, focusing on the innovative approaches to enhance sun protection efficacy tailored to individual needs. We conducted an electronic search of the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Skin Group Specialised Skin Register, and TESEO. Specific search terms related to personalized photoprotection and the variables of age, genetic predisposition, skin phototype, photodermatosis, and physiological conditions such as pregnancy, as well as lifestyle habits were used. The article highlights the challenges and opportunities in adopting personalized photoprotection strategies, aiming to promote skin health and prevent the harmful effects of UV radiation in the era of precision medicine.

Adsorption properties and mechanism of Cu(II) on virgin and aged microplastics in the aquatic environment.

Microplastics (MPs) migrate by adsorbing heavy metals in aquatic environments and act as their carriers. However, the aging mechanisms of MPs in the environment and the interactions between MPs and heavy metals in aquatic environments require further study. In this study, two kinds of materials, polyamide (PA) and polylactic acid (PLA) were used as target MPs, and the effects of UV irradiation on the physical and chemical properties of the MPs and the adsorption behavior of Cu(II) were investigated. The results showed that after UV irradiation, pits, folds and pores appeared on the surface of aged MPs, the specific surface area (SSA) increased, the content of oxygen-containing functional groups increased, and the crystallinity decreased. These changes enhanced the adsorption capacity of aged MPs for Cu(II) pollutants. The adsorption behavior of the PA and PLA MPs for Cu(II) conformed to the pseudo-second-order model and Langmuir isotherm model, indicating that the monolayer chemical adsorption was dominant. The maximum amounts of aged PA and PLA reached 1.415 and 1.398 mg/g, respectively, which were 1.59 and 1.76 times of virgin MPs, respectively. The effects of pH and salinity on the adsorption of Cu(II) by the MPs were significant. Moreover, factors such as pH, salinity and dosage had significant effects on the adsorption of Cu(II) by MPs. Oxidative complexation between the oxygen-containing groups of the MPs and Cu(II) is an important adsorption mechanism. These findings reveal that the UV irradiation aging of MPs can enhance the adsorption of Cu(II) and increase their role as pollutant carriers, which is crucial for assessing the ecological risk of MPs and heavy metals coexisting in aquatic environments.

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.