Search Results (1,702)

The precise control of droplet movement on surfaces remains a major challenge in the field of smart surfaces. Conventional systems based on light, electric, or magnetic stimuli often require the addition of corresponding photothermal, conductive, or magnetic particles into the droplets, which may lead to droplet contamination and hinder encapsulation of drugs or cells for practical application. In the present study, a photo-responsive composite functional surface was designed and prepared. The functional surface contains a liquid crystal elastomer (LCE) layer which is placed underneath a pre-lubricated polydimethylsiloxane surface. Taking advantage of the photo-induced thermal response of the cross-linked LCE network, upon local irradiation with ultraviolet light, the illuminated region of the LCE layer rapidly generates dynamic heating, creating a temperature gradient across the droplet. This gradient alters the surface tension of the solid surface, disrupts the symmetry of contact angles of the droplet, thereby inducing directional droplet movement along the surfaces. The present study provides a non-contact and fast approach for the fabrication of smart surfaces towards more complex droplet manipulation. Full article

Ultraviolet (UV) radiation was selected in this study to evaluate its assistant remediation effects on Cr-contaminated soil. Various remediation materials, including corn stover (CS), corn stover biochar (CSB), polypyrrole-modified 44 corn stover (PPy-CS), and polypyrrole-modified corn stover biochar (PPy-CSB), were employed to evaluate their synergistic effects with UV radiation. The results showed that UV radiation increased the toxicity characteristic leaching procedure (TCLP) Cr(VI) when no other remediation was added to the contaminated soil. However, when the remediation materials were added, with UV radiation, the contents of TCLP-Cr(VI) decreased, while the contents of Cr(III) increased, and the removal rates of TCLP-Cr(VI) in contaminated soil treated by CSB, PPy-CSB, CS, and PPy-CS were 18.7%, 7.6%, 11.0%, and 8.2% higher than those of the non-irradiated groups, respectively. Notably, the CS group demonstrated superior efficacy in Cr(VI) removal compared with CSB under UV irradiation. Meanwhile, characteristic analysis including electron paramagnetic resonance (EPR), Fourier-transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS) assisted us in finding reaction mechanisms, which implied that UV irradiation could enhance the content of oxygen free radicals on the material surface and effectively activate the reactions between Cr(VI) and remediation materials. This study verified that UV irradiation could also be a promising tool in the remediation of heavy-metal-contaminated soil. Full article

Injectable fillers that combine immediate volume restoration with a sustained biological response remain of considerable interest in minimally invasive aesthetic medicine. In this study, a hydroxyapatite-loaded methacrylated recombinant type III collagen microgel (HAp@rhCol III-MA) was prepared by in situ coprecipitation and photocrosslinking. Recombinant type III collagen (rhCol III) was functionalized with methacryloyl groups to obtain rhCol III-MA, after which a calcium phosphate phase was mineralized in the presence of the modified collagen and the collagen phase was crosslinked under ultraviolet irradiation. More than 80% of the microgel particles prepared at 900 rpm were 20–80 μm in diameter. Spectroscopic, elemental, thermal, and diffraction analyses supported the incorporation of a poorly crystalline, HAp-compatible calcium phosphate phase, while rheological measurements showed higher storage and loss moduli than those of rhCol III-MA gel. HAp@rhCol III-MA did not reduce NIH-3T3 cell viability at the tested concentrations and enhanced HUVEC scratch closure and tube-network formation in vitro. Following subcutaneous implantation in rats, the microgel retained more volume than rhCol III-MA during the early and intermediate observation periods, with residual volumes of 56.58 ± 3.03 mm³ for HAp@rhCol III-MA and 52.80 ± 1.79 mm³ for rhCol III-MA at day 59; the commercial type I collagen comparator retained 123.23 ± 2.80 mm³. The composite caused no evident tissue injury and was associated with progressive collagen deposition and a low, declining CD68-positive response. These findings support further investigation of HAp@rhCol III-MA as an injectable dermal-filling material, while long-term persistence and clinical injection performance remain to be established. Full article

This study fabricated a silver-based composite photocatalytic material (Ag/AgVO₃/g-C₃N₄) for antibiotic degradation driven by visible light. The composite was prepared using the water bath method, and its morphology, structure and optical properties were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and Ultraviolet-Visible (UV-vis) diffuse reflection spectroscopy. The photocatalytic activity of the composite was evaluated within 240 min under visible-light irradiation, and its degradation effect was quantified using tetracycline hydrochloride as the target pollutant, applying different conditions of composite proportions and dosage, initial concentration of the contaminant, and pH. The experimental results demonstrated that the composite doped with Ag⁺ had a higher degradation effect on tetracycline hydrochloride. The highest degradation rate of tetracycline hydrochloride (reaching 86.64%) was achieved at a composite ratio of Ag/AgVO₃/5g-C₃N₄, dosage of 0.8 g·L⁻¹, and initial concentration of tetracycline hydrochloride of 10mg·L⁻¹. This rate is approximately 1.4 times and 1.7 times those of the pure-phase g-C₃N₄ and AgVO₃, and the degradation rate remains stable at 81.52% after 4 cycles of experiments. The favorable stability of the photocatalyst was also verified through a stability test. Full article

Ultraviolet sensitivity in birds is generally attributed to short-wavelength-sensitive type 1 single cones, but ultraviolet radiation may influence the retina through several additional pathways. We reviewed molecular, optical, physiological, and behavioral evidence for canonical and putative noncanonical ultraviolet detection in the avian retina. Under photopic conditions, short-wavelength-sensitive type 1 cones provide an established chromatic pathway, whereas secondary ultraviolet absorption bands of other cone pigments may contribute at high irradiance. Under scotopic conditions, particularly in rod-dominated owls lacking functional ultraviolet- or violet-sensitive type 1 cones, the secondary ultraviolet absorption band of rhodopsin provides a plausible achromatic pathway. Ultraviolet-sensitive opsin 5 in inner-retinal neurons and Müller glia may mediate local regulatory or non-image-forming responses. We also examine fluorescence of oil droplets in double cones as a possible route into the luminance system. Previous reports described ultraviolet-induced visible fluorescence in chicken retinal oil droplets and fluorescence of chicken double-cone droplets under blue excitation, although physiological activation of the adjacent visual pigment by droplet fluorescence has not been established. These mechanisms are not mutually exclusive, and their relative contributions probably depend on irradiance, adaptation state, ocular-media transmission, receptor abundance, and behavioral context. Receptor-specific physiological and behavioral experiments are required to distinguish between them. Full article

Skin photoaging is closely associated with oxidative stress, inflammatory responses, and dysregulated collagen metabolism. Paeonol (Pae) possesses antioxidant and anti-inflammatory activities; however, its poor water solubility and short skin retention time limit its topical application. In this study, a transdermal delivery system based on a carboxymethyl chitosan (CMCS)/Carbomer 940 (Carb940) composite gel loaded with hydroxypropyl-β-cyclodextrin inclusion complexes of paeonol (Pae-CD) was developed. Pae-CD was prepared using an ultrasound-assisted saturated aqueous solution method, and the physicochemical properties, sustained-release behavior, transdermal permeation, antioxidant activity, and safety of Pae-CD/gel were evaluated. Furthermore, a mouse model of skin photoaging induced by combined ultraviolet A (UVA)/ultraviolet B (UVB) irradiation was established to investigate its reparative effects in vivo. The results showed that Pae-CD/gel exhibited a homogeneous three-dimensional porous structure, favorable sustained-release characteristics, enhanced skin retention capacity, and good cellular compatibility. In vivo experiments demonstrated that Pae-CD/gel markedly ameliorated ultraviolet-induced skin dryness, abnormal epidermal thickening, and dermal collagen loss. It also reduced oxidative stress and inflammatory factor levels, down-regulated matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-3 (MMP-3) expression, and promoted the restoration of collagen type I (COL-1) and hydroxyproline (HYP) levels. Systemic safety evaluation revealed no obvious toxicity. In summary, Pae-CD/gel exerts antioxidant and anti-inflammatory effects and regulates collagen metabolism by enhancing transdermal delivery and local retention, thereby providing a safe and effective topical delivery strategy for the repair of skin photoaging. Full article

As microplastics act as ubiquitous carriers for endocrine-disrupting additives in aquatic environments, understanding their leaching dynamics is of critical concern. This study systematically investigated the effects of ultraviolet (UV) aging on the release behavior of phthalates (di-n-butyl phthalate [DnBP] and di(2-ethylhexyl) phthalate [DEHP]) from polyvinyl chloride (PVC) microplastics across diverse environmental conditions, along with the underlying mechanisms. Kinetic analyses and experimental results indicated that the release of plasticizers under UV irradiation was driven by a dynamic competition between the photochemical stability of the plasticizers and the aging of the microplastics: the apparent cumulative amount of photolabile DnBP decreased as irradiation time increased. In contrast, the release of photoresistant DEHP significantly exceeded that under dark conditions in the later stages of aging. Furthermore, highly variable environmental factors exhibited significant selectivity in regulating the release: high ionic strength inhibited plasticizer release through salting-out and cationic bridging effects, with divalent ions (Mg²⁺) in particular suppressing DEHP release by up to 96%; conversely, dissolved humic acid caused a 13-fold surge in DEHP release via robust hydrophobic solubilization. Comprehensive multitechnique characterizations (including SEM, FTIR, XRD, and XPS) confirmed that UV-induced aging—encompassing intense dehydrochlorination reactions, a marked increase in polar oxygen-containing functional groups and the amorphization of crystalline regions—fundamentally dismantled the internal mass transfer resistance, thereby creating physical pathways for the outward migration of internal plasticizers. Ultimately, this study emphasizes that the synergistic interactions between material aging and complex hydrochemical conditions must be fully integrated into assessments of long-term ecological risks and predictions of the real-world environmental fate of microplastic-associated contaminants. Full article

Ultraviolet B (UVB) irradiation is a major environmental factor contributing to skin photoaging by inducing oxidative stress, apoptosis, inflammation, and extracellular matrix degradation in dermal fibroblasts. This study investigated the photoprotective effects of Thua Nao, a Thai fermented soybean, against UVB-induced human dermal fibroblast damage, and explored its underlying mechanisms. The dichloromethane fraction of Thua Nao (TN-DC) most effectively mitigated UVB-induced cell death. HPLC analysis identified daidzein and glycitein as the major constituent isoflavones in TN-DC that protect fibroblasts against UVB-induced cellular damage. Mechanistically, they reduced apoptosis by suppressing caspase-9 and poly (ADP-ribose) polymerase activation and preserving mitochondrial membrane potential. Additionally, they suppressed inflammatory mediators including interleukin-6, interleukin-8, inducible nitric oxide synthase, and cyclooxygenase-2 and prevented collagen loss. These protective outcomes correlated with decreased intracellular reactive oxygen species and upregulated endogenous antioxidant enzymes including superoxide dismutase 1 and heme oxygenase. Signaling pathway analysis revealed that TN-DC activated the pro-survival extracellular-signal-regulated kinase and Akt pathways in UVB-exposed cells. Conversely, daidzein and glycitein selectively attenuated c-Jun N-terminal kinase activation, downregulating downstream pro-inflammatory cytokines and mediators. Collectively, these findings demonstrate that TN-DC protects human dermal fibroblasts against UVB-induced photoaging primarily by enhancing endogenous antioxidant defense, thereby preserving cellular homeostasis through coordinated regulation of oxidative stress-responsive signaling pathways. Full article

Excessive ultraviolet A (UVA) irradiation disrupts extracellular matrix (ECM) homeostasis in skin photoaging by impairing the balance between synthesis and degradation, yet whether silk fibroin peptide (SF), a small bioactive peptide from Bombyx mori, can restore this balance through mechanotransduction pathways remains unknown. Herein, we demonstrate that SF dose-dependently rescues human dermal fibroblasts (HDFs) from UVA-induced oxidative stress, senescence, and ECM disintegration. Notably, SF not only suppresses reactive oxygen species (ROS) and restores activities of antioxidant enzymes, but is also associated with the recovery of the ITGB1-FAK mechanotransduction axis, as evidenced by restored fibronectin levels and increased focal adhesion kinase (FAK) phosphorylation, whereas integrin β1 (ITGB1) expression itself was not significantly altered. This mechanosensory recovery is accompanied by restoration of downstream transforming growth factor-β (TGF-β)/Smad signaling, upregulation of COL1A1, COL3A1 and ELN transcription, and simultaneous suppression of MMP1, MMP3 and MMP9. Unlike conventional antioxidants or exogenous collagen supplements that merely counteract oxidative damage or provide structural substitutes, SF may facilitate recovery of the disrupted cell–matrix interface potentially through modulation of integrin-mediated mechanochemical signal conversion, which may contribute to ECM homeostasis restoration. Collectively, SF promotes mechanotransduction, offering a potential paradigm for anti-aging strategies that target ECM homeostasis through integrin signaling. Full article

The conformational composition and ultraviolet photochemistry of neutral valine isolated in solid parahydrogen were investigated using high-resolution infrared spectroscopy, ultraviolet photolysis, and density functional theory calculations. The observed infrared spectrum was analyzed by combining calculated vibrational frequencies, relative infrared intensities, and conformer-specific photolysis kinetics. Four distinct photolysis-rate categories were identified experimentally, providing direct evidence for the presence of at least four valine conformers in the parahydrogen matrix. The combined spectroscopic and kinetic analysis enabled assignment of the major absorption bands to the six lowest-energy conformers and revealed pronounced conformer-dependent photostability of valine. Upon irradiation at 213 nm, valine undergoes predominantly $\alpha$-carbonyl C–C bond cleavage, producing the hydrocarboxyl (HOCO) radical and 2-methylpropan-1-imine as the major photoproducts. The formation of HOCO is consistent with previous studies of amino acids isolated in solid parahydrogen and supports a common photodissociation pathway among aliphatic amino acids. The hydrogen-bonded Type II conformer exhibits significantly slower photodepletion than the Type I conformers, indicating that intramolecular hydrogen bonding enhances ultraviolet photostability of valine. These results establish a direct relationship between molecular conformation and photochemical stability in isolated amino acids while further demonstrating the unique capability of solid parahydrogen matrix isolation for conformer-specific photochemical investigations. Full article

Stibnite (Sb₂S₃), the predominant antimony-bearing sulfide mineral, represents a major natural source of antimony (Sb) in mining-impacted environments. Although humic acid (HA) is ubiquitous in mine wastes and surface waters, its influence on the oxidative transformation and mobilization of Sb from Sb₂S₃ under photochemical conditions remains poorly understood. Here, the coupled effects of HA, controlled ultraviolet irradiation and pH on Sb₂S₃ weathering and Sb mobilization were systematically investigated through batch dissolution experiments combined with hydroxyl radical (·OH) determination, elemental sulfur (S⁰) analysis and complementary solid-phase characterization. Sb release increased with increasing pH and was further enhanced by HA, particularly under circumneutral and alkaline conditions. Controlled UV irradiation further increased Sb mobilization under the investigated conditions, with a more pronounced effect in HA-containing systems. The enhanced Sb mobilization was accompanied by increased ·OH production and greater S⁰ accumulation, indicating increased oxidative activity during weathering. SEM, EDS and FTIR analyses further revealed progressive surface morphological and compositional changes, whereas XRD showed that the bulk crystalline structure of Sb₂S₃ was largely preserved. XPS revealed the formation of oxidized Sb- and S-containing surface species, providing evidence for progressive surface chemical transformation. These results indicate that HA and controlled photochemical conditions were associated with enhanced Sb mobilization and oxidative transformation at the Sb₂S₃-solution interface, while the overall weathering remained predominantly surface-confined. The findings highlight the importance of considering natural organic matter, photochemical conditions and pH together when evaluating Sb mobility from sulfide minerals in mining-impacted environments. Full article

Botrytis cinerea, the causal agent of gray mold or Botrytis rot on many vegetable and fruit crops worldwide, is ranked among the main limiting factors for strawberry production, being able to strongly compromise the quality, shelf life, and commercial value of fruit. UV-C is considered an environmentally friendly strategy for postharvest protection for several commodities. In this regard, this research evaluated the performance of short-wavelength UV-C radiation in reducing postharvest Botrytis decay, extending or maintaining the shelf life and quality of strawberry fruit, and detecting possible negative effects. The topic is of growing interest, as it falls within the strategic priorities of so-called “Green Technologies” to pursue a sustainable agriculture and safe food supply by minimizing fungicide use as much as possible. UV-C exposure (at a rate of 1428 J m⁻²) by means of a UV-C lamp (15 W) at a source distance of 25 cm for just 1 min provided significant reductions (from 41 up to almost 80%) depending on the artificial or natural decay pressure of gray mold caused by B. cinerea on strawberry fruit without phytotoxic effects. Analyses performed under both refrigerated and room-temperature storage conditions at different day intervals showed that postharvest UV-C does not significantly affect key chemical parameters, including the ascorbic acid content, total sugars, pH, and titratable acidity of strawberry fruit. Thus, UV-C exposure for a brief time, especially if combined with a low temperature, can be effectively considered for sustainable protection of strawberry fruit at the postharvest stage, providing a theoretical basis for further elucidation of the action modes for this and other targets, and potential large-scale application. Full article

Ultraviolet B (UVB) radiation is a primary cause of DNA damage in the skin, which is often a precursor to skin cancer. Natural products represent a rich source of compounds with unexplored photoprotective properties. Our previous work identified 3-methoxybenzyl isothiocyanate (MBITC), a meadowfoam derivative, as a promising UVB-absorptive agent that reduces DNA damage and cell proliferation; however, its clinical use is limited by dose-dependent cytotoxicity. To address this, we synthesized a novel amide lipid conjugate of MBITC, N-(3-methoxybenzyl)eicos-5-enamide (MBA), and evaluated its photoprotective efficacy and mechanism of action. Our findings demonstrate that MBA exhibited remarkably reduced cytotoxicity compared to its parent compound, while effectively retaining its photoprotective properties. In human primary keratinocyte cultures, MBA significantly reduced UVB-induced DNA damage, as evidenced by a decrease in cyclobutane pyrimidine dimers (p < 0.05) and γ-H2A.X (p < 0.05). Furthermore, MBA increased the expression of DNA damage response (DDR) proteins and DNA damage-binding protein 1 (DDB1) (p < 0.05) and the activation of Ataxia Telangiectasia and Rad3-related protein (ATR) (p < 0.05), a master regulator of DDR and repair pathways. These findings suggest that MBA acts through direct UVB absorption and/or the engagement of DDR pathways following irradiation, highlighting its potential use as a novel photoprotective compound. Full article

It is well-known nowadays that the usage of conventional opaque photovoltaics in agricultural practices has negative effects on crops growth, mainly due to the shading effect they cause. On the other hand, most of the emerging semi-transparent solar cells do not demonstrate the appropriate optical characteristics and scalability to attain their viable integration in agriculture, undermining their commercialization. This study deals with the development of wavelength-selective semi-transparent dye-sensitized solar cells (DSSCs) using the scalable slot-die deposition method. These devices are designed to provide high transparency in the photosynthetically active radiation (PAR) region and effectively exploit the near-ultraviolet to blue-visible spectrum for power production, simultaneously protecting cultivations from harmful short-wavelength irradiation. To this aim, a new quinoline-based dye and a highly transparent iodine-free electrolyte were employed in DSSCs, giving an external quantum efficiency of 70% for wavelengths up to 500 nm and a PAR transmittance on the level of 50% (55% crop growth factor). Additionally, the light-to-electricity conversion efficiency of these devices is high for both front- and rear-side illumination under all-weather irradiation conditions (up to 94% bifaciality factor). Finally, two new figures-of-merit (greenhouse compatibility factor, agrivoltaic performance factor) are introduced to quantify the balance of photovoltaic performance and agronomic functionality. Full article

The study concerns the simulation of an active personal protective mask that performs air purification of incoming and outgoing air to and from the user using ultraviolet germicidal irradiation (UVGI). The specific method for determining the radiation dose is done using a CFD simulation of the process of breathing to determine the duration of the irradiation of the air. Additionally, an optical simulation is performed in order to determine the average irradiance in the illuminated zone. For the purposes of the UVGI, a radiation dose of 20–40 J/m² is sufficient to achieve LD90 when applied to most Flu and Corona viruses. Full article