Search Results (655)

A literature review about polymer composites reveals that natural fibers have been widely used as a reinforcement phase in recent years. In this framework, the lignocellulosic fibers have received marked attention because of their environmental, thermomechanical, and economic advantages for many industrial sectors. This research aims to identify the impact behavior of ramie reinforced epoxy composites with medium- and high-volume fractions of fibers in intact (nonaged) and aged conditions as well as to analyze if the influence of interface quality on the impact fracture energy can be described by a novel mathematical model. To reach these objectives, the study is designed with three groups (40%, 50%, and 60% of fiber theoretical volume fractions) of intact specimens and three groups of aged samples by condensation and ultraviolet radiation (C-UV) simulation containing the same fiber percentages. Consecutively, impact strength and fracture surface analyses are done to expand the comprehension of the damage mechanisms suffered by the biocomposites and to support the development of the mathematical relation. Certainly, this novel model can contribute to more sustainable and greener industries in the near future. Full article

Blackcurrant is a notable superfruit in Europe, and its vitamin C content surpasses the well-known blueberry superfruit. However, due to its short shelf life during storage, consumption is mainly accounted by frozen berries, extracts, and concentrates. This study applied an intensity of 1.2 W/m² UVC with different durations, including control (non-treated), UVC irradiation for 0.5 h (0.5 h treatment), UVC irradiation for 1 h (1 h treatment), and UVC pretreatment for 2 h (2 h treatment) to blackcurrant berries before storage. Fundamental physical (firmness and weight loss) and physicochemical characteristics (SSC, pH, and acids), microbial population changes, total phenolic content, antioxidant capacity, and specific phenolic compound changes were evaluated every five days over a twenty-day storage period. The results indicated that the longer the UVC pretreatment, the lower the water weight losses during storage. Meanwhile, the UVC pretreatment significantly affected the blackcurrant soluble solid content, resulting in higher soluble solid contents detected in the blackcurrants with the higher doses of UVC. For the mold population control, UVC effects were highly correlated with the pretreatment duration. However, UVC did not have a significant influence on the berry pH and acid contents, but the storage length slightly increased the pH and decreased the acids. At the same time, UVC pretreatment did not affect the berry firmness, polyphenols, ascorbic acid content, or antioxidant capacities, which were primarily influenced by the storage duration. The monophenolic compounds detected before and after storage indicated that more than one hour of UVC radiation influenced most of the phenolic contents largely before storage. The UVC pretreatment has also influenced some phenolic compounds. After storage, half an hour of UVC pretreatment increased cyanidin levels, and two hours of UVC pretreatment increased catechin and epicatechin levels. However, most of the compounds remained at similar amounts during storage in each treatment. Further research is needed to improve the UVC radiation time length or intensity or explore other technology combinations to optimize UVC pretreatments for blackcurrant storage. Full article

Efficient detection of toxic and flammable vapors remains a major technological challenge, especially for environmental and industrial applications. This paper reports on the fabrication technology and gas-sensing properties of nanostructured Ga₂O₃/GaS_0.98Se_0.02. The β-Ga₂O₃ nanowires/nanoribbons with inclusions of Ga₂S₃ and Ga₂Se₃ microcrystallites were obtained by thermal treatment of GaS_0.98Se_0.02 slabs in air enriched with water vapors. The microstructure, crystalline quality, and elemental composition of the obtained samples were investigated using electron microscopy, X-ray diffraction, and Raman spectroscopy. The obtained structures show promising results as active elements in gas sensor applications. Vapors of methanol (CH₃OH), ethanol (C₂H₅OH), and acetone (CH₃-CO-CH₃) were successfully detected using the nanostructured samples. The electrical signal for gas detection was enhanced under UV light irradiation. The saturation time of the sensor depends on the intensity of the UV radiation beam. Full article

The quality effects of spectral irradiance conditions during papaya (Carica papaya L.) drying were investigated using three different dryers: a solar dryer with dynamic irradiance control (SDIC), a cylindrical solar dryer (CSD), and a solar simulator dryer (SSD). This study builds upon previous PDLC film applications in solar drying by specifically examining its impact on phytochemical preservation and color degradation, addressing gaps in spectral-specific effects on food quality parameters. The drying conditions were as follows: a temperature of 50 °C for each method, 700 w/m² for both SDIC and solar simulator dryers (SSD), and full solar irradiance for the cylindrical solar dryer (CSD). The cylindrical solar dryer exhibited 210 min of drying time due to higher solar irradiance than SDIC (300 min), while SSD lasted 180 min. Drying rates were highest for CSD (0.056 g H₂O/g d.m. min⁻¹), followed by SDIC (0.027 g H₂O/g d.m. min⁻¹). Color analysis revealed that CSD resulted in the most significant color degradation, followed by SSD and SDIC. This was attributed to the varying spectral composition of radiation in each method. The CSD, with a full solar spectrum, including higher UV and visible radiation, induced more pronounced color changes than SDIC, which received lower intensity radiation in these ranges. Chemical analyses showed that SSD samples had the highest antioxidant activity (1432.91 µmol TE/g dw by ABTS) and phenolic content (58.92 mg GAE/100 g), suggesting simulated conditions may better preserve certain phytochemicals. SDIC maintained better carotenoid-related color parameters while showing intermediate antioxidant levels (1084.09 µmol TE/g dw). These results demonstrate that irradiance control significantly impacts drying efficiency and quality parameters. Full article

Microbial contamination of food can lead to faster spoilage and infections. Therefore, disinfection processes are required that have a low detrimental effect on the nutritional content. Concerning radiation disinfection, two spectral ranges have recently become important. The Far-UVC spectral range, with a wavelength below 230 nm and visible violet light. In this study, leaf spinach was used to investigate the extent to which these radiations inactivate Escherichia coli, but also to determine if the vitamin C or chlorophyll content was reduced. Frozen spinach leaves (Spinacia oleracea) were contaminated with E. coli × pGLO and irradiated with either a 222 nm krypton chloride lamp or 405 nm LEDs. The achieved bacterial reduction was determined by plating the irradiated samples on agar plates and subsequent colony counting. The vitamin C concentration was determined by means of redox titration, and the concentrations of chlorophyll a and chlorophyll b were determined using spectrometry. Both irradiations exhibited a strong antimicrobial impact on E. coli. The average log reduction doses were about 19 mJ/cm² (222 nm) and 87 J/cm² (405 nm), respectively. The vitamin C concentration decreased by 30% (222 nm) or 20% (405 nm), and the chlorophyll concentrations decreased by about 25%. Both irradiation approaches are able to substantially reduce microorganisms on spinach leaves by two orders of magnitude, but this is associated with a reduction in the nutrient content. Full article

The robust structure of algal cell walls presents a major barrier in the recovery of fermentable sugars and intracellular lipids for biofuel production. This study investigates the effectiveness of ultraviolet (UV) radiation and UV-assisted hydrogen peroxide (UV/H₂O₂) pretreatment on a local mixed marine algal culture to enhance biofuel production through cell wall disruption. Local mixed cultures of marine microalgae (LMCMA) were pretreated with UV for various exposure times (5–30 min) and with UV/H₂O₂ using H₂O₂ concentrations ranging from 0.88 to 3.53 mM. The impact of pretreatment was evaluated based on morphological changes (SEM and TEM), elemental composition (C, H, N), sugar release, and downstream fermentation yields of ethanol, methanol, 1-propanol, 1-butanol, and 1-pentanol using Saccharomyces cerevisiae. UV pretreatment at 20–30 min yielded the highest carbohydrate release (up to 0.025 g/gDCW), while UV/H₂O₂ at 1.76 mM achieved maximum sugar liberation (0.0411 g/gDCW). Fermentation performance was enhanced under optimized conditions, with peak ethanol yields of 0.3668 g ethanol/g carbohydrates (UV, 30 min, 48 h) and 0.251 g ethanol/g (UV/H₂O₂, 0.88 mM, 24 h). This study also demonstrated selective production of higher alcohols under varying fermentation temperatures (30–37 °C). These findings highlight the potential of combining oxidative pretreatment and process optimization to enhance biofuel recovery from environmentally relevant algal biomass. Full article

Prolonged ultraviolet (UV) exposure accelerates aging and degradation, while conventional constant-intensity UV simulations do not reflect the variable nature of outdoor radiation. Aging duration and film thickness are both key factors affecting Rubber-Modified Asphalt (RMA), but how their combination influences RMA remains unclear. To address this limitation, this research employed accelerated aging experiments under variable-intensity UV radiation to investigate the performance and aging mechanism of RMA across different aging durations and asphalt film thicknesses. Rheological properties were analyzed through rheological tests, and the UV aging mechanisms of RMA were revealed using FTIR and SEM. The results revealed that crumb rubber improved RMA’s UV aging resistance, including high-temperature performance, fatigue life, and low-temperature cracking resistance. Aging effects were more influenced in RMA with thinner films under prolonged UV exposure. After nine cycles of ultraviolet aging, the rutting resistance, elastic recovery, fatigue life, and low-temperature cracking resistance of RMA with a 1 mm film thickness were 1.33, 1.11, 0.54, and 0.67 times, respectively, those of RMA with a 2 mm film thickness subjected to three UV aging cycles. RMA demonstrated comparable high-temperature performance and elastic recovery under UV aging conditions corresponding to a 1.5 mm film thickness aged for three cycles and a 2.0 mm film thickness aged for six cycles, as well as a 1.0 mm film thickness aged for six cycles and a 1.5 mm film thickness aged for nine cycles. FTIR showed that the increased activity of C=C and C-H under photo-oxidative aging caused a greater impact on the carbonyl groups than the sulfoxide groups. Under high-intensity UV radiation, RMA with thinner films exhibited greater rubber powder detachment, increased surface oxidation, and a substantial widening of cracks. The rubber powder absorbed UV radiation, enhancing the stability of RMA. The maximum crack width of the 1 mm NA was twice that of RMA. These provided insight into the microstructural pattern of cracking resistance degradation caused by aging. This research provides theoretical support for the optimization of the anti-aging performance of RMA. Full article

Folic acid (FA) is used as a targeting ligand for targeted drug delivery to tumor cells, some types of which overexpress folate receptors on their surface. However, while the preparation of conjugates containing FA may comprise a multi-step process, FA presents low photostability under UV irradiation. In addition, FA undergoes radiolysis under the action of ionizing radiation, which is utilized for drug sterilization. In this study, we investigate the stability of FA in a conjugate (FA-PVP-C₆₀) with fullerene C₆₀ and polyvinylpyrrolidone under the action of UV (205–400 nm) and electron irradiation (doses from 2 to 8 kGy) at different pH (4.5, 7.2, 10.7). The degradation of FA is studied using fluorescence and UV–Vis spectroscopy. It is found that the fullerene C₆₀ in the FA-PVP-C₆₀ conjugate suppresses the degradation of FA during both photolysis and radiolysis, which is confirmed by the decrease in the quantum yield of fluorescence and the radiation chemical yield of FA destruction accompanied by increasing fullerene content in the conjugate (from 2.8 to 10 wt.%). Full article

This study investigates the effects of destructive climatic factors on the mechanical and performance properties of various structural materials, encompassing both polymers and metals. Over recent decades, the growing adoption of synthetic polymers has revolutionized engineering applications, yet their susceptibility to environmental degradation poses significant challenges. This research emphasizes the need for comprehensive testing under both operational and environmental stressors, including extreme temperatures, UV radiation, and moisture, to assess material durability and performance. Mechanical tests were conducted at ambient (25 °C) and low temperatures (−50 °C) to evaluate the strength and strain responses of selected materials. Additionally, a 12-month accelerated aging process using UV radiation and elevated temperatures was performed to simulate long-term environmental exposure. Parameters such as Shore D hardness, gloss, and mass were measured at regular intervals to quantify material degradation. The results revealed significant differences in performance across material types. Among polymers, laser-extruded and milky plexiglass, as well as solid polycarbonate, exhibited satisfactory resistance to aging, with minimal changes in mechanical properties. However, high-impact polystyrene displayed substantial deformation and hardness loss after prolonged UV exposure. For metals, aluminum and stainless steel (304 and 316) demonstrated exceptional durability, retaining structural and aesthetic properties after 12 months of accelerated aging, whereas galvanized steel exhibited pronounced corrosion. The study highlights the critical interplay between mechanical loading and environmental factors, stressing the importance of material selection tailored to specific climatic conditions. It further underscores the value of integrating experimental findings with predictive models, such as finite element analysis, to enhance the design and longevity of engineering materials. The findings provide actionable insights for industries operating in temperate climates, where materials are subjected to diverse and cyclic environmental stressors. Recommendations are offered for selecting resilient materials suitable for protective housings and structural components. Full article

Background/Objectives: Non-melanoma skin cancer (NMSC) is among the most common cancers in the United States, with solar ultraviolet (UV) radiation being a primary etiological factor. T-LAK cell-originated protein kinase (TOPK), a serine/threonine kinase activated by solar UV, has been implicated in skin carcinogenesis. This study aimed to investigate the mechanistic role of TOPK in solar UV-induced skin damage and tumor development. Methods: RNA sequencing (RNA-seq) was performed on skin tissues from wild-type (WT) and TOPK knockout (KO) mice, with or without solar UV exposure, to identify TOPK-regulated genes and pathways. Follow-up experiments using Western blotting, immunofluorescence, and luciferase assays were conducted in vitro and in vivo. Functional assays included 3D spheroid and Transwell co-culture systems involving cutaneous squamous cell carcinoma (cSCC) and fibroblast cells. Results: TOPK deletion altered gene expression profiles and inhibited solar UV-induced activation of multiple signaling pathways, including cytokine–cytokine receptor interaction, PI3K/AKT, MAPKs, PKG, cAMP, and calcium signaling. RNA-seq and protein analyses identified interleukin-19 (IL19) as a key downstream effector suppressed by TOPK deletion. In cSCC and fibroblast cells, TOPK knockdown reduced IL19 expression and secretion. IL19 promoted cSCC growth and activated PI3K/AKT, ERK, and TOPK pathways. Additionally, chronic TGFβ exposure increased IL19 expression and activated fibroblasts, as indicated by elevated αSMA and FAPα levels. Conclusions: These findings establish TOPK as a central regulator of solar UV-induced skin carcinogenesis, partially via modulation of IL19 signaling and fibroblast activation. Targeting TOPK may offer a novel strategy for the prevention and treatment of NMSC. Full article

The Atacama Desert, an unexplored habitat, offers intriguing potential for natural product chemistry due to the unique adaptations of microorganisms to aridity, extreme salinity, and high UV radiation. Over several years, soil samples were collected from various locations across the desert, leading to the isolation of diverse microorganisms. This paper presents the isolation and structural characterisation of two new 10-membered lactones, curvulalide B and C (3 and 4). These compounds are epimers of each other and are produced by one of the fungi isolated from the samples collected, using LC–MS and 1D and 2D NMR techniques. The compounds were tested against the ESKAPE pathogens, bovine mastitis pathogens, and Cryptococcus neoformans but were inactive against them. Full article

Prolonged exposure to ultraviolet (UV) radiations represents a significant risk factor and may lead to various skin disorders, premature aging, and an increased susceptibility to skin cancers. Recently, probiotics have emerged as promising candidates for fortifying the skin’s natural defences through their diverse mechanisms. The aim of the present work was exploring the potential of five heat-treated probiotics (Skinbac^TM, Probiotical Research S.r.l., Novara, Italy), as protective agents against UVA and UVB damages on human keratinocyte line (HaCaT) and human skin 3D model (Phenion^® Full-Thickness Skin Model, Henkel AG & Co. KGaA, Dusseldorf, Germany). The protective role toward artificially induced oxidative stress was evaluated by determining the residual viability after UV exposure and analyzing gene expression of markers involved in apoptosis (Tumor protein 53), inflammation/immunosuppression (Interleukin 6), oxidative stress (oxidative stress response enzyme heme oxygenase 1), investigated using quantitative real-time PCR. Additionally, we examined the protective effects of these strains, testing them on Normal Human Epidermal Keratinocytes (NHEK) irradiated with UVC, specifically, evaluating the expression of tight junction proteins, including claudin 1, claudin 4, and occludin, by ELISA. The tested heat-treated probiotics effectively protected from UVA, UVB, and UVC damage on all end points analyzed, revealing their capacity to enhance barrier protection in cases of damage and their potential for innovative skincare strategies centered around probiotic-based formulations for enhanced protection against UV-induced skin damage. Full article

Biological, physiological, and psychological stressors cause a “stress response” in our bodies. Stressors that are sensorily perceived (either acute or chronic) trigger hormonal responses from the sympathetic nervous system—the SAM and HPA axis—that effect intended organs to alert the individual. Other stressors have a direct effect on the target organ(s) of the body—e.g., physical injury and wounds, toxins, ionizing, and UV radiation. Both kinds of stressors change cell equilibrium, often leading to reactive oxygen species (ROS) accumulation and cellular damage. Among the signaling pathways involved in fighting these stressors, the c-Jun-N-terminal kinases (JNK) respond to diverse kinds of stressors. This review focuses on JNK1 and JNK2, both of which are ubiquitously present in all cell types, and attention is paid to gastrointestinal tract epithelial cells and their response—including tight junction disruption and cytoskeletal changes. We discuss the seemingly opposite roles of JNK1 and JNK2 in helping cells choose pro-survival and pro-apoptotic pathways. We examine the common features of the JNK protein structure and the possibilities of discovering JNK-isoform-specific inhibitors since, although JNK1 and JNK2 are involved in multiple diseases, including cancer, obesity, diabetes, musculoskeletal and liver disease, no cell-specific or isoform-specific inhibitors are available. Full article

Candida auris possesses distinctive features that facilitate its persistence and transmission in healthcare settings, causing outbreaks of infection that are difficult to treat. So, emphasis has been placed on implementing measures for controlling, eliminating, and preventing fungal transmission, such as environmental disinfection and patient decolonization. This review aimed to understand and analyze the agents for environmental disinfection and patient decolonization reported in the last 5 years. The PubMed database was reviewed, using the terms “Candida auris”, “disinfection”, and “decolonization”. Only original papers, published between 2020–2025, in English or Spanish, that included relevant information on the topic, were selected. After the selection process, 52 articles were chosen to analyze the agents for environmental disinfection and decolonization of C. auris. Natural and synthetic disinfectants and ultraviolet radiation were reported for the environmental disinfection, with variable efficacy, depending on factors such as concentration and exposure time. Natural and synthetic antiseptics were also reported for decolonization, with varying efficacy. For example, 2% chlorhexidine shows a 0.5 log reduction, while at concentrations >10% it is >4 log. However, most have only been tested in animal models. Based on the review, Far-UV-C radiation (222 nm) is safe and appropriate to mitigate (up to 1 log reduction) the spread of C. auris in the hospital setting. However, it is important to consider that the cost and limited availability of the device present a barrier to its implementation. Patient decolonization is still challenging nowadays due to the absence of agents with proven high efficacy in humans. Full article

Leachates generated from the degradation of green waste and biosolids from urban wastewater treatment plants (WWTPs) pose significant environmental concerns due to high concentrations of organic pollutants and heavy metals. This study proposes a hybrid treatment strategy combining electrocoagulation (EC) and UVC-activated TiO₂ photocatalysis to remediate leachates produced in laboratory-scale biocells. Initial characterization revealed critical pollutant levels: COD (1373 mg/L), BOD₅ (378 mg/L), total phosphorus (90 mg/L), ammoniacal nitrogen (201 mg/L), and metals such as Ni, Pb, and Mn levels all exceeding those set out in the Ecuadorian discharge regulations. Optimized EC achieved removal efficiencies of 62.6% for COD, 44.4% for BOD₅, 89.8% for phosphorus, and 86.2% for color. However, residual contamination necessitated a subsequent photocatalytic step. Suspended TiO₂ under UVC irradiation removed up to 81.8% of the remaining COD, 88.7% of the ammoniacal nitrogen, and 94.4% of the phosphorus. Levels of heavy metals such as Zn, Fe, Pb, Mn, and Cu were reduced by over 80%, while Cr⁶⁺ was nearly eliminated. SEM–EDS analysis confirmed successful TiO₂ immobilization on sand substrates, revealing a rough, porous morphology conducive to catalyst adhesion; however, heterogeneous titanium distribution suggests the need for improved coating uniformity. These findings confirm the potential of the EC–TiO₂/UVC hybrid system as an effective and scalable approach for treating complex biocell leachates with reduced chemical consumption. Full article