Search Results (1,079)

Background: Cutaneous synthesis of vitamin D depends primarily on exposure to solar ultraviolet B (UVB) radiation. Nevertheless, populations in the Mediterranean region, including pregnant women, continue to experience high rates of hypovitaminosis D. Pregnancy is a particularly vulnerable period due to increased physiological demands and reduced outdoor activity. The aim of this study was to examine the seasonal and environmental determinants of maternal and neonatal vitamin D status in an urban Greek population. Methods: We conducted a cross-sectional observational study on 248 pregnant women and their neonates admitted for delivery at Tzaneio General Hospital of Piraeus between September 2019 and January 2022. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured and temporally matched with environmental variables including UV index, sunshine hours, ambient temperature, and PM2.5 levels. Results: Both maternal and neonatal 25(OH)D levels exhibited marked seasonal variation, with levels peaking in late summer and declining sharply in winter. A significant positive correlation was observed between UV index and vitamin D concentrations (r = 0.45, p < 0.001), while elevated PM2.5 concentrations were inversely associated with vitamin D status. Despite supplementation, insufficiency persisted in most neonates, particularly during the low-UV season. This underlines the need for comprehensive prenatal care strategies, integrating both supplementation policies and individualized nutritional counseling, to better secure maternal and neonatal vitamin D adequacy. Conclusions: Seasonal and environmental factors, particularly solar radiation and particulate air pollution, have a decisive role in determining maternal and neonatal vitamin D status, even in regions with abundant sunlight. These findings emphasize the importance of adaptive prenatal care strategies that combine supplementation with dietary counseling and take into account seasonal variation and air quality. In addition, the study provides novelty by integrating maternal–neonatal vitamin D status with environmental exposure metrics such as UV and PM2.5. Full article

Species-specific husbandry guidelines remain limited for blue-tongued skinks (Tiliqua scincoides), especially in relation to ultraviolet B (UVB) lighting and vitamin D requirements. This study aimed to determine whether UVB exposure is necessary for these skinks and how long 25-hydroxyvitamin D (25-OHD) concentrations persist after UVB withdrawal. Eleven adult skinks who had been fed with wet cat food were exposed to 12 or 2 h of UVB per day for four weeks. Plasma 25-OHD concentrations were very low at the baseline, and significantly increased post-UVB in both groups (p < 0.01), with the 12-hour group increasing from baseline concentrations of 18.5 [12.8–20.5] nmol/L to 820 [730–1251.3] nmol/L and the 2-hour group increasing from baseline concentrations of 22 [15.5–22] nmol/L to 635 [401–892.5] nmol/L. Following the discontinuation of UVB exposure, 25-OHD gradually declined and was not significantly different from baseline concentrations at 7 and 4 months for the 12-hour and 2-hour groups, respectively. Dietary vitamin D₃ (2.5 IU/g as dry matter basis), provided through wet cat food alone, appeared insufficient to support sustained plasma 25-OHD concentrations. These findings strongly suggest that blue-tongued skinks rely on UVB exposure to increase their 25-OHD concentrations. Moreover, the shorter 2-hour exposure provided a significant rise in 25-OHD concentrations and remained above baseline for 4 months, suggesting the shorter exposure can benefit these animals, while potentially reducing secondary risks associated with UVB exposure. Full article

Organic pollutants pose a significant threat to both the ecological environment and human health. In this study, BiVO₄@ZnO heterojunction composites were synthesized via a two-step hydrothermal method. The incorporation of polyhedral BiVO₄ onto the flower-like structure of ZnO effectively enhanced the photocatalytic performance of the composite. Compared with ZnO flower-like nanorods, the BiVO₄@ZnO heterojunction composite photocatalysts achieved degradation efficiencies of 93.18% (k = 0.09063) and 89.64% (k = 0.007661) for methylene blue (MB) within 30 min under ultraviolet and visible light irradiation, respectively. The photocatalytic activity of the BiVO₄@ZnO composites was also evaluated against various organic dyes, including rhodamine B (RhB), Congo red (CR), methyl orange (MO), and methylene blue (MB). Under ultraviolet light, the catalysts showed particularly high activity toward MB and CR. The enhanced photocatalytic performance can be attributed to two main factors: firstly, the heterojunction facilitates the separation of photogenerated electron-hole pairs, thereby improving photocatalytic efficiency; secondly, the composite exhibits a broadened and enhanced light absorption range. Furthermore, the BiVO₄@ZnO heterojunction composites demonstrate excellent cyclic catalytic stability and structural integrity. This study offers a clean and efficient strategy for the photocatalytic degradation of aqueous organic pollutants. Full article

Background: Folic acid (FA), also known as vitamin B9, functions as a co-factor in many cellular processes. Ultraviolet radiation (UV) has been shown to cause the formation of free radicals, and chronic exposure of the skin to UV radiation has been demonstrated to result in many adverse effects. Skin protection against harmful environmental factors is one of the aims of cosmetic products. One such substance is folic acid. However, aqueous FA solutions decompose after exposure to UV radiation, and the decomposition products can exhibit variable pro/anti-oxidative roles depending on the cell type and its environment. Objectives: The objective of the present study was to demonstrate the effectiveness of folic acid as a UV-protective agent in vitro cell culture model. Methods: The experimental model comprised an in vitro culture of normal human fibroblasts derived from adult skin (NHDF-Ad). Paramagnetic electron resonance (EPR) was used to assess the interaction of folic acid with free radicals after exposure to UV radiation. RT-qPCR was utilized to evaluate the impact of ultraviolet (UV) radiation on the expression of selected cell cycle regulatory genes (CCND1, P53, BAX, and BCL-2) in vitro cultured fibroblasts that were protected by folic acid. Results: EPR studies revealed the antioxidant properties of folic acid. Free radical forms of folic acid are induced during UV irradiation. The strong effect of UV irradiation on interactions of folic acid with free radicals was observed. The interaction was found to be weaker for the irradiated samples. Molecular studies have demonstrated a decline in the BAX/BCL-2 ratio in cells that have been treated with folic acid and exposed to UV radiation in comparison to the BAX/BCL-2 ratio observed in cells that have been exposed exclusively to UV radiation and not treated with folic acid. Conclusions: Whilst molecular and EPR studies both confirm the effectiveness of folic acid as a UV-protective ingredient in cosmetics and pharmaceutical products, further research in this area is required. Full article

Indole carboxylic acids are endogenous tryptophan metabolites that have demonstrated a variety of bioactivities, including anticancer effects. Specifically, indole acetic acid (IAA) elicits anticancer activity when combined with ultraviolet B or reactive oxygen species (ROS) generators. Primaquine (PQ) is an approved drug which elicits antimalarial activity through ROS generation. We investigated the effects of ICA, IAA, PQ, their combination and PQ–indole carboxamide conjugates on the viability of selected cancer cell lines. We identified PQ–indole carboxamide 2 which elicited more potent antiproliferative effects than PQ and ICA/PQ combination. Our data revealed that compound 2 derived a significant part of its antiproliferative effect from ROS generation. Full article

Background: Ultraviolet B (UVB) radiation accelerates skin aging by inducing oxidative stress, collagen degradation, and cellular senescence. Although Petasites japonicus is known for its antioxidant properties, its anti-photoaging potential remains underexplored. This research explored the protective properties of a hot water extract from P. japonicus leaves (KP-1) against photoaging caused by UVB exposure. Methods: Hairless mice were exposed to UVB three times per week and orally administered KP-1 for 13 weeks. Wrinkle formation, epidermal thickness, skin hydration, and collagen content were assessed. Protein expression related to MAPK/AP-1, TGF-β/Smad2/3, and p53/p21 pathways was analyzed by Western blotting. Results: KP-1 significantly reduced UVB-induced wrinkle area, epidermal and dermal thickening, and transepidermal water loss while restoring collagen density and skin hydration. KP-1 inhibited MMP-1 expression, enhanced COL1A1 levels, suppressed MAPK/AP-1 activation, and activated TGF-β/Smad2/3 signaling. It also balanced p53/p21 expression and restored cyclin D1 and CDK4 levels, thereby preventing UVB-induced senescence. Conclusions: The findings of this research revealed that KP-1 can serve as a promising natural substance for safeguarding the skin from damage and aging caused by UVB exposure. Full article

Introduction: Chronic spontaneous urticaria (CSU), vitiligo, and Hashimoto’s thyroiditis (HT) frequently co-occur in the same patients, suggesting a shared autoimmune pathogenesis. These conditions are increasingly recognized as components of polyautoimmunity, with overlapping clinical, immunological, and pathogenetic features. Among the proposed common mechanisms, vitamin D deficiency and oxidative stress (OS) have emerged as key contributors. We aimed to explore the shared immunopathogenic pathways linking these conditions, with a focus on the interplay between vitamin D status and redox imbalance. Methods: An extensive narrative review of the current literature regarding the associations among CSU, vitiligo, and HT, focusing on the role of vitamin D status, OS, and nitrosative stress, and shared immunological pathways was conducted. Discussion: Vitamin D deficiency was consistently observed across all three conditions and is associated with increased disease activity and poorer clinical outcomes. Several polymorphisms in the vitamin D receptor (VDR) and binding protein genes correlate with disease susceptibility. OS and nitrosative stress markers, such as malondialdehyde (MDA) and nitric oxide (NO) metabolites, are elevated in patients with CSU, vitiligo, and HT, and are linked to tissue-specific immune activation, apoptosis, and loss of self-tolerance. Evidence suggests that vitamin D and antioxidant supplementation may provide clinical benefit. In vitiligo, narrowband ultraviolet B (NB-UVB) phototherapy not only promotes repigmentation through melanocyte stimulation but also reduces ROS production and modulates local immune responses. Conclusions: The coexistence of CSU, vitiligo, and HT reflects a broader systemic autoimmune tendency, with vitamin D deficiency and redox imbalance serving as potential unifying mechanisms. Routine assessment of vitamin D levels and OS parameters may enhance diagnostic precision and inform therapeutic strategies. Antioxidant-based interventions represent promising avenues in the integrated management of autoimmune skin and endocrine disorders. Full article

Ultraviolet B (UVB) radiation triggers DNA damage and immune suppression, establishing conditions favorable for skin carcinogenesis. Previous studies have shown that a downstream adaptor for Toll-like receptors (TLRs), myeloid differentiation primary response 88 (MyD88), plays a role in UVB-induced DNA damage and immunosuppression. However, specific mechanisms for the effects on dendritic cells and T cells remain poorly understood. The objective of this study is to determine the role of MyD88 and TIR-domain-containing adaptor inducing interferon-β (TRIF), another key TLR downstream adaptor, in UVB-induced suppression of dendritic cell activity and T cell function. MyD88−/−, Trif−/−, and wild-type (WT) mice were evaluated for UVB-induced effects on dendritic cell, T cells, and contact hypersensitivity responses in skin. MyD88−/− mice exhibited significant resistance to UVB-induced immune suppression, compared to Trif−/− mice and wild-type controls. The MyD88 deficiency significantly reduced UVB-induced Treg cells that were CD4⁺CD25⁺Foxp3⁺ and produced interleukin (IL)-10. Moreover, it significantly inhibited the UVB-induced suppression of IL-12/IL-23 producing CD11c⁺ dendritic cells. Further experiments confirmed that MyD88 conditional knockout (MyD88fl/flXCD11c.Cre) mice were protected against UVB-induced immune suppression. Dendritic cells from MyD88 genomic or conditional knockout mice were resistant to UVB-induced reduction of major histocompatibility complex (MHC) class II antigens. These findings show that MyD88 plays a key role in UVB-induced immune suppression. The deficiency in the MyD88 gene inhibits UVB-induced suppression of CD11c+ dendritic cell (DC) activity and reduces UVB-induced development of Treg cells. Our studies demonstrate a new mechanism for MyD88-mediated regulation of UVB-induced immune suppression. Full article

Plant functional traits (PFTs) serve as key predictors of plant survival and adaptation to environmental gradients. Studies on intraspecific variation in PFTs are crucial for evaluating species’ adaptation to projected climate change and developing long-term conservation strategies. This study systematically investigated PFT responses in Polyspora chrysandra (Theaceae, Yunnan, China) through an integrated multivariate analysis of 20 leaf functional traits (LFTs) and 33 environmental factors categorized into geographical conditions (GCs), climate factors (CFs), soil properties (SPs), and ultraviolet radiation factors (UVRFs). To disentangle complex environmental–trait relationships, we employed redundancy analysis (RDA), hierarchical partitioning (HP), and partial least squares structural equation modeling (PLS-SEM) to assess direct, indirect, and latent relationships. Results showed that the intraspecific coefficient of variation (CV) ranged from 7.071% to 25.650%. Leaf tissue density (LTD), specific leaf area (SLA), leaf fresh weight (LFW), leaf dry weight (LDW), and leaf area (LA) exhibited moderate intraspecific trait variation (ITV), while all other traits demonstrated low ITV. Reference Bulk density (RBD) and Silt emerged as significant factors driving the variation. Latitude (Lat), altitude (Alt), and mean warmest month temperature (MWMT) were also identified as key influences. HP analysis revealed Silt as the most important predictor (p < 0.05). Latent variable analysis indicated descending contribution rates: SPs (31.51%) > GCs (11.52%) > CFs (11.04%) > UVRFs (10.29%). Co-effect analysis highlighted significant coupling effects involving RBD and cation exchange capacity of clay (CECC), as well as organic carbon content (OCC) and UV-B seasonality (UVB2). Path analysis showed SPs as having the strongest influence on leaf thickness (LT), followed by GCs and UVRFs. These findings provide empirical insights into the biogeographical patterns of ITV in P. chrysandra, enhance the understanding of plant environmental adaptation mechanisms, and offer a theoretical foundation for studying community assembly and ecosystem function maintenance. Full article

Lignocellulosic biomass may play a major role in the production of biofuels, bioplastics, sugar, paper, and various other industrial products. In addition, it is a key trait in plants due to its contribution to lodging resistance. Fiber also shows a significant negative correlation with most yield traits and all sugar traits. As the most harvested crop globally by tonnage, sugarcane is an important resource for both sugar and bioenergy production. In this study, a panel of sugarcane clones was utilized to investigate the fiber content. This panel included 17 core parental lines derived from 11 countries involved in sugarcane cultivation and breeding. It represented the genetic base of commercial sugarcane breeding programs in China and other countries. The objective of this research was to identify molecular markers and candidate genes associated with fiber content in sugarcane using genome-wide association studies (GWASs). By integrating 5,964,084 high-quality single-nucleotide polymorphisms (SNPs) with phenotypic data collected across five different environments, a total of 69 SNPs spanning 41 quantitative trait loci (QTLs) were identified. Based on functional annotations and genomic positions, these QTLs contained 52 candidate genes. These candidate genes encoded the ultraviolet-B receptor (UVR8), leucine-rich repeat receptor-like kinases (LRR-RLKs), serine/threonine kinases (STKs), cellulose synthase (CESA), vegetative cell wall protein glycoproteins1 (gp1), F-box protein, MYB transcription factor, and so on. These genes could directly or indirectly influence the fiber content in sugarcane. Furthermore, according to previous studies, among these candidate genes, five located in four QTL regions were proposed to be the most critical. They included Sspon.02G0041160-2C, encoding CESA; Sspon.03G0039010-1C and Sspon.03G0039030-1C, both encoding gp1; Sspon.06G0023090-1B, encoding an F-box protein; and Sspon.07G0019440-2C, encoding a MYB transcription factor. The genetic basis of the fiber content was explored using elite breeding lines and their derivatives from the Chinese sugarcane breeding program. These candidate genes represent promising targets for future functional studies and may contribute to the development of different types of sugarcane varieties with correspondingly suitable fiber content through marker-assisted selection. Full article

The bark of Dillenia indica L. is a rich source of phenolic and triterpenoid compounds, including betulinic acid (BA), known for their antioxidant and anti-aging properties. This study investigated the antioxidant potential of a BA-enriched extract through a multidisciplinary approach combining computational, experimental, and cell-based evaluations. Molecular docking and molecular dynamics simulations revealed that BA binds stably to Kelch-like ECH-associated protein 1 (KEAP1), suggesting activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Extraction conditions were optimized using response surface methodology (RSM) and artificial neural network (ANN) modeling, yielding the maximum total phenolic content (TPC; 85.33 ± 2.26 mg gallic acid equivalents/g) and total flavonoid content (TFC; 75.60 ± 1.66 mg catechin equivalents/g), with ANN demonstrating superior predictive performance compared to RSM. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) confirmed the presence of BA in the optimized extract. Simulated gastrointestinal digestion revealed reductions in TPC, TFC, and radical scavenging activity during the gastric phase. In ultraviolet B (UVB)-irradiated human keratinocyte (HaCaT) cells, the optimized extract significantly reduced intracellular reactive oxygen species (ROS) and upregulated the KEAP1-Nrf2-heme oxygenase-1 (HO-1) pathway, confirming its antioxidant mechanism. These findings highlight the extract’s stability, bioactivity, and mechanistic efficacy, supporting its application as a nutraceutical ingredient for combating oxidative stress and skin aging. Full article

Ultraviolet-B (UV-B, 280–315 nm) radiation is an increasingly relevant abiotic stressor under climate-change scenarios, yet crop-specific tolerance mechanisms remain insufficiently understood. We compared maize (Zea mays L.) and grain sorghum (Sorghum bicolor L.) seedlings exposed to eight UV-B durations (1–12 h), applied every second day over 14 days of juvenile growth. Highly sensitive, non-invasive biophoton emission imaging (NightShade^® LB 985), chlorophyll content measurements (SPAD-502), and morphophysiological traits (shoot/root lengths, biomass, root collar diameter) were assessed. Biophoton emission kinetics measured immediately and 24 h after exposure suggested differing temporal defense dynamics: maize showed an early modest increase, a mid-exposure reduction, and a later pronounced peak around 6 h. Sorghum tended to reach a dominant peak earlier (≈3 h) and maintain relatively steady emissions thereafter, potentially reflecting more uniform antioxidant activation. SPAD patterns aligned with these trends: maize retained higher chlorophyll at lower exposures (0–6 h; p < 0.05), whereas sorghum surpassed maize at extreme exposures (10–12 h; p = 0.036). Morphophysiological traits showed no significant treatment effects, though minor low-dose peaks suggested possible ROS-mediated stimulation. These results indicate species-specific UV-B acclimation patterns and demonstrate the utility of biophoton imaging as a rapid screening tool for assessing crop resilience. Full article

Several minerals are known to undergo chromatic variations when exposed to sunlight, particularly ultraviolet (UV) radiation. These phases, defined as photosensitive, exhibit colour change due to photochemical reactions. To understand this phenomenon, this study investigates the colour alteration in 26 common mineral phases, aiming to better understand their behaviour under artificial ageing conditions. Each mineral was firstly chemically characterised by SEM-EDS to identify common chromophoric impurities. Subsequently, samples were exposed to UV radiation in the climatic chamber. The colour shifts were semi-quantitatively assessed in the CIEL*a*b* colour space after ageing. The results indicate that just 4 minerals out of 26 display negligible colour variation, whereas 22 show evident colour changes. These findings highlight the vulnerability of photosensitive minerals to UV-induced colour changes and raise concerns regarding their behaviour in artworks, historical surfaces, and cultural heritage objects. As such minerals are frequently found in the heritage field, understanding their photochemical responses is essential for developing informed preventive conservation strategies, particularly concerning light exposure in both museum and outdoor contexts. Full article

A damping spacer rod is a key protective device in ultrahigh voltage transmission lines, which not only keeps the distance of split wires and limits the whipping and collision caused by the relative motion between sub-wires, but also inhibits the vibration of wires. This study aims to solve the problem of typical faults, such as loose wire clamps, that are prone to occur in damping isolation rods during long-term operation in ultra-high voltage transmission lines. Taking the spacer rod FGZ-450/34B as the object, a new high-pressure casting process for spacer rod frames is explored. The spacer rods were simulated by using the ABAQUS finite element software to predict the stress distribution and identify the dangerous sections. Based on this, the mold process was optimized to avoid die-casting defects. Meanwhile, mechanical property tests were carried out on the products produced by the two types of molds. The research finds that by optimizing the mold process, the die-casting quality of the dangerous section of the spacer rod can be effectively improved, and the best high-pressure die-casting scheme has been obtained through comparison. This research achievement provides technical support for enhancing the anti-vibration performance, anti-loosening reliability, short-circuit current thermal shock resistance, and anti-ultraviolet aging performance of damping isolation rods. It is of great significance for ensuring the stable operation of ultra-high voltage transmission lines and improving the production process level of damping isolation rods. Full article

(1) Background: The pursuit of ingredients that possess both anti-melanogenesis and post-inflammatory hyperpigmentation (PIH) prevention effects has become a new research frontier in cosmetics, though there is little work on plant extract-derived ingredients in this direction. (2) Methods: The study involved evaluating the impact of dark tea extract on melanin content and tyrosinase activity in B16 cells. Meanwhile, Ultraviolet B (UVB)-irradiated assays were conducted on HaCaT cells to assess the secretion of inflammatory factors (IL-1α and IL-1β) and paracrine melanogenic factors (α-MSH, bFGF, and ET-1). Additionally, we performed quantitative real-time polymerase chain reaction (RT-PCR) tests to determine whether the signaling pathways of anti-melanogenesis and PIH punctuation are incorrect. (3) Results: The results showed that dark tea extract significantly inhibited melanin content and tyrosinase activity in B16 cells. In HaCaT cells, the extract reduced the secretion of the aforementioned inflammatory and paracrine melanogenic factors, thereby inhibiting PIH. Moreover, the RT-PCR and the Western Blot results indicated that the dark tea extract could inhibit the melanogenesis signaling pathway of α-MSH/MC1R/MITF and their downstream multiple targets of TYRP-1, TYRP-2, and TYR in B16 cells, while it exerted a PIH inhibition effect by downregulating the p38 MAPK/Nrf2/HO-1 signaling pathway. (4) Conclusions: This study suggests that dark tea extract can not only suppress melanogenesis through multiple targets but also can inhibit UVB-induced PIH, hinting at its skin-brightening efficacy as an agent for the restoration of pigmentation disorders. Full article