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Industrial wastewater treatment using UV irradiation in combination with oxidants or catalysts (TiO2) has attracted attention as a promising substitute for conventional methods. Studying the preparation and characterization of TiO2–SnO2 nanocomposites with different ratios, as well as their use in the enhanced photocatalytic degradation of acid red 37 dye in aqueous solution under UV irradiation as a model pollutant, are the goals of the research. The crystalline structures of the prepared nanomaterials were confirmed by XRD and the surface morphology of the samples was studied by TEM. The elemental compositions of the catalysts were confirmed by EDAX. The optical properties of the powder samples were analyzed with UV–Vis spectroscopy and their band gaps were estimated. The photocatalytic degradation was investigated using several advanced oxidation techniques using a batch photoreactor. The TiO2–SnO2 (90:10) nanocomposite showed the best degradation efficiency. [ABSTRACT FROM AUTHOR]

The artificial nociceptor is a device that simulates the biological nociception system, which has a wide range of applications in the fields of medicine, rehabilitation, and robotics. Multimodal nociceptors can respond to diverse stimuli, including visual, mechanical, and thermal, and so on, and then convert them into neural signals for processing by the brain. Herein, a back‐gate optoelectronic transistor based on 2D InSe/MoS2 heterostructure is demonstrated. By employing energy band alignment of the heterojunction, the device exhibits high sensitivity (106) and high responsivity (330 AW−1) to harmful UV irradiation, which can be exploited to emulate the key features of nociceptors, including "threshold," "relaxation," "no adaptation," and "sensitization." Moreover, the device can be operated in a two‐terminal mode, memristive characteristics are obtained through applying source–drain voltages. Then, artificial nociceptive behaviors responding to external electrical pulses have been successfully emulated. Finally, the modulation of nociceptive sensitivity can be achieved through the controlling gate bias, which fully demonstrates the potential of our device for the application of biomimetic multimodal artificial nociceptors in future neuromorphic sensory system. [ABSTRACT FROM AUTHOR]

Overexposure to ultraviolet (UV) radiation accelerates skin aging, resulting in wrinkle formation, reduced skin elasticity, and hyperpigmentation. UV irradiation induces increased matrix metalloproteinases (MMPs) that degrade collagen in the extracellular matrix. Skin aging is also accompanied by epigenetic alterations such as promoter methylation by DNA methyltransferases, leading to the activation or suppression of gene expression. Although carnitine acetyltransferase (CRAT) is implicated in aging, the effect of UV on the expression of CRAT and regulatory mechanisms of UV-induced MMP-1 expression remain unknown. We investigated changes in CRAT expression upon UV irradiation and its effect on MMP-1 expression. Primary human dermal fibroblasts were UV irradiated with either control or 5-AZA-dC. CRAT knockdown or overexpression was performed to investigate its effect on MMP-1 expression. The mRNA level was analyzed by quantitative real-time PCR, and protein level by western blotting. The expression of CRAT was decreased in UV-irradiated human skin in vivo and in human dermal fibroblasts in vitro. CRAT was downregulated upon UV irradiation by hypermethylation, and treatment with 5-Aza-2′-deoxycytidine, a DNA methyltransferase inhibitor, reversed UV-induced downregulation of CRAT. CRAT knockdown activated the JNK, ERK, and p38 MAPK signaling pathways, which increased MMP-1 expression. Stable overexpression of CRAT alleviated UV-induced MMP-1 induction. CRAT downregulation caused by promoter hypermethylation may play an important role in UV-induced skin aging via upregulation of MMP-1 expression. • CRAT is significantly downregulated by promoter hypermethylation. • CRAT affects skin photoaging by inducing MMP-1 via the ERK, JNK, and p38 pathways. • Epigenetic regulation of CRAT may enable therapeutic approaches for anti-photoaging. [ABSTRACT FROM AUTHOR]

The composition and concentration of a low-molecular organic additive, leading to a significant improvement in the electrical properties of low-density polyethylene of high pressure grade 10,803-020, were experimentally determined. Phthalic anhydride and phthalic acid were used as modifying organic additives. The content of additives in the polyethylene of high pressure composition varied in the range of 0.01–0.1 wt%. It has been shown that the content of 0.05 wt% phthalic anhydride and phthalic acid in the composition polyethylene of high pressure (PEHP + 0.05 wt% PhAn + 0.05 wt% PhAc) is the optimal composition, since the electrical strength of the film has increased significantly. The dependences of the dielectric loss tangent and specific volumetric electrical resistance on temperature, as well as the kinetics of physicochemical changes in them under the influence of electrical discharges in air and UV irradiation, have been studied. It was established that the dielectric characteristics of the polymer composition PEHP + 0.05 wt% PhAn (storage life 40 years) changed slightly. [ABSTRACT FROM AUTHOR]

Adhesive bonding is a suitable joining method to satisfy the increasing industrial demand for carbon fiber-reinforced polymers without the need for a machining process. However, thermoplastic-based carbon fiber-reinforced polymers have small adhesive strength with structural thermoset adhesives. In this study, an ultraviolet irradiation surface treatment was developed to improve the adhesive bonding strength for polyamide-based carbon fiber-reinforced polymer. The type of ultraviolet wavelength, irradiation distance and irradiation time were optimized. Surface treatment with simultaneous UV irradiation of 185 nm and 254 nm wavelength generated unbound N-H stretching that was capable of chemical bonding with epoxy adhesives through a photo-scission reaction of the amide bond of polyamide matrix. Therefore, ultraviolet irradiation treatment improved the wettability and functional groups of the polyamide-based carbon fiber-reinforced polymers for adhesive bonding. As a result, the adhesive strength of the polyamide-based carbon fiber-reinforced polymers was increased by more than 230%. [ABSTRACT FROM AUTHOR]

Objective: The development of controllable gene editing systems based on the CRISPR/Cas technology is a problem of immediate interest in modern molecular biology and genetic engineering. An interesting solution of this problem is modification of guide RNA by introduction of photocleavable linkers. Methods: We developed an approach to the synthesis of cyclic photocleavable guide crRNA for the CRISPR/Cas9 system with a photolinker based on 1-(2-nitrophenyl)-1,2-ethanediol (PL). In cyclic form, such guide RNA is not functional. Upon irradiation by UV-light, such guide RNA is linearized and CRISPR/Cas9 system is activated. Two chemical methods for the cyclization of RNA were tested: Michael reaction (thiol-maleimide condensation) and Cu-catalyzed azide-alkyne cycloaddition (CuAAC, click-chemistry reaction). For this purpose, 5′,3′-modified RNA containing reactive groups were prepared. Results and Discussion: The advantages of the CuAAC reaction for cyclic RNA preparation was demonstrated. Efficiency of cyclic RNA depends on their secondary structure and on the ability of reactive groups to move closer. A series of photocleavable and control non-cleavable cyclic crRNA was obtained. It was shown that cyclic crRNAs guide Cas9 nuclease for plasmid cleavage less efficiently, but linearization of photocleavable cyclic crRNA increases the extent of plasmid cleavage. Conclusions: The developed approach allows to synthesize cyclic photocleavable RNA that can be used for spatiotemporal activation of guide RNA for gene editing. Photoregulation of gene editing will allow minimizing the off-target effects. [ABSTRACT FROM AUTHOR]

Aspergillus flavus and its mycotoxin aflatoxin (AF) are widely present in the environment and cause various acute and chronic diseases in humans and animals. UV irradiation has been a versatile method for disinfecting A. flavus and detoxifying AFs. Combined effects of UV and other agents were scarcely tested yet. Here, we investigated the combinatorial effects of UVC and peroxymonosulfate (PMS) on the disinfection of A. flavus and accumulation of AFB1 under aqueous conditions. UVC efficiently disinfected A. flavus in a dose-dependent manner. PMS (~4 mM) exhibited no disinfection but enhanced the inactivation activity of UVC. Notably, PMS or UVC (72 J/cm²) increased the accumulation of AFB1 in the mycelia. Higher (144 J/cm²) doses of UVC suppressed AFB1 accumulation. At the genetic level, PMS and UVC upregulated the expression of the AF biosynthetic genes aflS and aflR. In contrast, UVC degraded AFB1 in vitro, which was enhanced by PMS treatment. The in-vivo and in-vitro studies indicated that AFB1 accumulation may be compromised by the dual effects of UVC and PMS on the upregulation of AF biosynthesis and degradation activities. In conclusion, PMS and UVC are efficient disinfecting agents against A. flavus but also stimulate AF biosynthesis under moderate treatment conditions. [ABSTRACT FROM AUTHOR]

In this work, Ce- and Li-doped CaF2 phosphor (CaF2:Ce,Li) was synthesized by the combustion technique. Structural and morphological analysis of the synthesized material has been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD pattern reveals the formation of a pure phase of the CaF2 crystal with a crystallite size of 717 nm. The luminescence properties were investigated by the thermoluminescence (TL) technique. The effect of sintering temperature on the TL glow curve of the pellets has been investigated for different temperatures (450, 500, 525, 550, and 575 °C). Pellets sintered at 525 °C and 550 °C presented higher sensitivity in their TL responses for gamma and UV irradiation, respectively. Samples irradiated with gamma radiation show two intense TL peaks centered at 172 °C and 275 °C. On the other hand, samples irradiated with UV radiation show two peaks centered at 195 and 280 °C. The intensity of the TL peaks increases with gamma radiation dose and UV irradiation time. The kinetic parameters of the glow curve peaks were determined through the combined analysis of the results obtained by the Tm-Tstop and deconvolution methods. [ABSTRACT FROM AUTHOR]

Nowadays, synthetic polymer (plastic) particles are ubiquitous in the environment. It is known that for several decades microplastics (MPs) have been accumulating in the World Ocean, becoming available to a large variety of marine organisms. Particularly alarming is the accumulation of aging plastic particles, as the degradation processes of such particles increase their toxicity. The diverse display of negative properties of aging MPs and its effect on biota are still poorly understood. In this study, in vitro experiments modeling the interaction of pristine and UV-irradiated aging polypropylene (PP) fragments with hemocytes and mitochondria of bivalve mollusks Mytilus sp. were performed. The appearance of free radicals in the environment was recorded by spectral characteristics of indicator dyes—methylene blue (MB) and nitroblue tetrazolium (NBT). It was found that due to photooxidation, aging PP fragments sorbed more than threefold MB on their modified surface compared to pristine samples of this polymer. Using NBT, the formation of reactive oxygen species in seawater in the presence of pristine and photoactivated PP was recorded. It was also found that photodegraded PP fragments largely stimulated the development of lipid peroxidation processes in mitochondrial membranes and reduced the stability of hemocyte lysosome membranes compared to pristine PP fragments. In general, the results obtained concretize and supplement with experimental data the previously stated hypothesis of toxicity of aging MPs. [ABSTRACT FROM AUTHOR]

Polymer modification of titania nanomaterials can provide media dispersibility and various functionalities onto the titania surface. Herein, we report the direct in situ polymer modification of the surface of titania nanotubes (TNTs) and titania nanoparticles (TNPs) via ultraviolet (UV)‐irradiated radical polymerization without any pretreatment of titania. The resulting polymer‐modified TNTs and TNPs dispersed well in solvents. The characterization of the products using various techniques including Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy‐energy dispersive X‐ray spectroscopy confirmed the successful modification of the TNT and TNP surfaces by the polymers produced via UV‐irradiated radical polymerization. The polymers on the titania surface were isolated by dissolving titania using hydrofluoric acid and analyzed by means of size exclusion chromatography and matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry. The polymer‐modified TNTs and TNPs maintained their photocatalytic activity in dye degradation under UV irradiation. Moreover, glycopolymer‐modified TNTs were successfully prepared using the UV‐irradiated polymerization system. The glycopolymer retained its lectin biding affinity on the TNT surface. [ABSTRACT FROM AUTHOR]

Gas sensing is essential for detecting and measuring gas concentrations across various environments, with applications in environmental monitoring, industrial safety, and healthcare. The integration of two-dimensional (2D) materials, organic materials, and metal oxides has significantly advanced gas sensor technology, enhancing its sensitivity, selectivity, and response times at room temperature. This review examines the progress in optically activated gas sensors, with emphasis on 2D materials, metal oxides, and organic materials, due to limited studies on their use in optically activated gas sensors, in contrast to other traditional gas-sensing technologies. We detail the unique properties of these materials and their impact on improving the figures of merit (FoMs) of gas sensors. Transition metal dichalcogenides (TMDCs), with their high surface-to-volume ratio and tunable band gap, show exceptional performance in gas detection, especially when activated by UV light. Graphene-based sensors also demonstrate high sensitivity and low detection limits, making them suitable for various applications. Although organic materials and hybrid structures, such as metal–organic frameworks (MoFs) and conducting polymers, face challenges related to stability and sensitivity at room temperature, they hold potential for future advancements. Optically activated gas sensors incorporating metal oxides benefit from photoactive nanomaterials and UV irradiation, further enhancing their performance. This review highlights the potential of the advanced materials in developing the next generation of gas sensors, addressing current research gaps and paving the way for future innovations. [ABSTRACT FROM AUTHOR]

In this study, a self-healing epoxy asphalt material was developed by incorporating coumarin groups. This material achieved microcrack self-repair under UV irradiation at 50 °C. Fluorescence microscopy observations and mechanical performance tests demonstrated significant advantages in crack filling and mechanical property recovery after repair, with the fracture toughness of the repaired epoxy asphalt reaching 69% of that in its original state. Furthermore, the synergistic effect of temperature and UV irradiation in the self-healing process enhanced the material's durability and service life. This research offers new insights and methods for developing more durable and long-lasting self-healing asphalt materials, showcasing the great potential of smart materials in infrastructure applications. [ABSTRACT FROM AUTHOR]

The time-dependent graphene oxide (GO) reduction in medium vacuum under ultraviolet (UV) irradiation at 365 nm has been investigated. We found that GO exposed to UV at room temperature and at a vacuum of about 10−1 mbar shows a notable oxidation for irradiation times up to about 60 min followed by a successive reduction up to 210 min. Characterization measurements have been performed mainly using the Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FTIR) and Raman spectroscopies. ATR-FTIR spectra, acquired in the (400–4000) cm−1 wavenumber range, have indicated an initial decrement of the IR transmission (oxidation process) with the exposure time up to about 60 min and a successive increase of the IR transmission (reduction process) for greater irradiation times up to 210 min. The IR transmission bands are attributed to the oxygen functional groups contained in GO which increase for low UV exposure times and gradually disappear during the UV-induced reduction process. Raman spectra confirm this interpretation showing a decrease of the AD/AG ratio value, with respect to the GO virgin value, for low UV exposure times and an increase for greater times. The GO oxidation and reduction processes, due to the UV GO treatment in medium vacuum conditions, have been also verified by energy dispersive X-ray fluorescence and surface wettability measurements. [ABSTRACT FROM AUTHOR]

Air quality, both outdoor and indoor, is the most critical element that we must protect for the entire environment. While the deterioration of air quality primarily causes respiratory diseases in living things, it also causes corrosive effects on nonliving things, such as corrosion caused by acid rain, which results from air pollution. Therefore, it is necessary to monitor and prevent air pollution by various methods. WHO plays an active role in protecting air quality through its mission. Plants are indispensable beings for the environment and life. They balance the CO2 concentration, temperature, and humidity in the air. Plants use CO2, light, and water during photosynthesis, which is necessary for their growth and development. They reduce the CO2 concentration in the environment. In addition, plants, depending on their leaf characteristics, can trap particulate matter in the atmosphere. Many studies have proven that plants positively affect indoor and outdoor air quality. In this review, we aim to summarize the results of some selected studies, provide information about the air purification capacities of the researched plants, and emphasize the topic's importance. [ABSTRACT FROM AUTHOR]

Plastic flotation is a promising process for sorting different types of plastics based on differences in wettability. Plastic surface modification is an important step to realize efficient flotation separation of mixed plastics. However, the large number of chemical reagents consumed in the plastic modification process may not only increase the process cost, but also generate new pollutants. This is extremely unfavorable for the large-scale use of plastic flotation to treat plastic pollution. In view of this, it is necessary to develop some novel, clean, and low reagent consumption plastic flotation processes. In our previous work, it was found that the surface wettability of plastics can be regulated based on the photochemical effect on plastic surface. And photochemical effect can be divided into photoaging effect and photo-reconstruction effect. But photoaging-plastic flotation or photo-reconstruction plastic flotation processes can only be used to treat binary or ternary plastic mixtures. Moreover, some processes still require the consumption of a large number of chemical reagents. Therefore, in this work, by combining photoaging effect with photo-reconstruction effect, we successfully developed a clean UV irradiation-plastic flotation process that only use very small amounts of chemical reagents. More importantly, this novel process can be used to separate multi-plastics. This work not only makes up for the shortcomings of our previous work, but also provides a new idea for the treatment of plastic pollution. [ABSTRACT FROM AUTHOR]

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Abstract Industrial wastewater treatment using UV irradiation in combination with oxidants or catalysts (TiO2) has attracted attention as a promising substitute for conventional methods. Studying the preparation and characterization of TiO2–SnO2 nanocomposites with different ratios, as well as their use in the enhanced photocatalytic degradation of acid red 37 dye in aqueous solution under UV irradiation as a model pollutant, are the goals of the research. The crystalline structures of the prepared nanomaterials were confirmed by XRD and the surface morphology of the samples was studied by TEM. The elemental compositions of the catalysts were confirmed by EDAX. The optical properties of the powder samples were analyzed with UV–Vis spectroscopy and their band gaps were estimated. The photocatalytic degradation was investigated using several advanced oxidation techniques using a batch photoreactor. The TiO2–SnO2 (90:10) nanocomposite showed the best degradation efficiency.

Abstract The Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument onboard the Mars 2020 Perseverance rover detected so far some of the most intense fluorescence signals in association with sulfates analyzing abraded patches of rocks at Jezero crater, Mars. To assess the plausibility of an organic origin of these signals, it is key to understand if organics can survive exposure to ambient Martian UV after exposure by the Perseverance abrasion tool and prior to analysis by SHERLOC. In this work, we investigated the stability of organo-sulfate assemblages under Martian-like UV irradiation and we observed that the spectroscopic features of phthalic and mellitic acid embedded into hydrated magnesium sulfate do not change for UV exposures corresponding to at least 48 Martian sols and, thus, should still be detectable in fluorescence when the SHERLOC analysis takes place, thanks to the photoprotective properties of magnesium sulfate. In addition, different photoproduct bands diagnostic of the parent carboxylic acid molecules could be observed. The photoprotective behavior of hydrated magnesium sulfate corroborates the hypothesis that sulfates might have played a key role in the preservation of organics on Mars, and that the fluorescence signals detected by SHERLOC in association with sulfates could potentially arise from organic compounds.

Vitamin D3 is a crucial fat-soluble pro-hormone essential for bolstering bone health and fortifying immune responses within the human body. Orodispersible films (ODFs) serve as a noteworthy formulation strategically designed to enhance the rapid dissolution of vitamin D, thereby facilitating efficient absorption in patients. This innovative approach not only streamlines the assimilation process but also plays a pivotal role in optimizing patient compliance and therapeutic outcomes. The judicious utilization of such advancements underscores a paradigm shift in clinical strategies aimed at harnessing the full potential of vitamin D for improved patient well-being. This study aims to examine the vitamin D3 ODF structure using spectroscopic techniques to analyze interactions with excipients like mannitol. Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy were utilized to assess molecular composition, intermolecular bonding, and vitamin D3 stability. Understanding these interactions is essential for optimizing ODF formulation, ensuring stability, enhancing bioavailability, and facilitating efficient production. Furthermore, this study involves a translational approach to interpreting chemical properties to develop an administration protocol for ODFs, aiming to maximize absorption and minimize waste. In conclusion, understanding the characterized chemical properties is pivotal for translating them into effective self-administration modalities for Vitamin D films. [ABSTRACT FROM AUTHOR]

Industrial discharge of hazardous organic and synthetic chemicals, such as antibacterials and dyes, poses severe risks to human health and the environment. This study was conducted to address the urgent need for efficient and stable zinc-oxide-based photocatalysts to degrade such pollutants. A novel approach to synthesizing silver-loaded zinc oxide (Ag@Z) catalysts was introduced by using a simple and efficient combination of hydrothermal and precipitation methods. Comprehensive characterization of Ag@Z photocatalysts was performed using XRD, XPS, Raman, UV–vis adsorption, FTIR, and SEM, revealing an enhancement of structural, optical, and morphological properties in comparison to pure zinc oxide. Notably, the 5%Ag@Z catalyst exhibited the highest degradation efficiency among the other synthesized catalysts under UV-C light irradiation, and enhanced the degradation rate of pure zinc oxide (Z) by 1.14 and 1.64 times, for Triclosan (TCS) and Methylene Blue (MB), respectively. the effect of catalyst dose and initial concentration was studied. A mechanism of degradation was proposed after investigating the effect of major reactive species. The 5%Ag@Z catalyst increased the photostability, which is a major problem of zinc oxide due to photocorrosion after reusability. We found that 50% and 74% of energy consumption for the photocatalytic degradation of TCS and MB by 5%Ag@Z, respectively, was saved in compassion with zinc oxide. The remarkable photocatalytic performance and the good recovery rate of Ag@Z photocatalysts demonstrate their high potential for photocatalytic degradation of organic contaminants in water. [ABSTRACT FROM AUTHOR]

Objective: The development of CRISPR/Cas-based gene-editing systems having a higher efficacy and specificity, and capable of changing activity in response to light irradiation is an urgent problem. A promising approach to this problem is to modify CRISPR/Cas components, in particular guide RNA, by introducing photocleavable linkers. We developed an approach to the synthesis of photocleavable single guide RNA (sgRNA) for the CRISPR/Cas9 system containing linkers on the basis of 1-(2-nitrophenyl)-1,2-ethanediol. Such photomodified guide RNAs are cleaved under UV irradiation, thereby inactivating the CRISPR/Cas9 system. Methods: Automatic solid-phase phosphoramidate method was used for photomodified sgRNA synthesis. Model plasmid was used for designed system testing. Results and Discussion: We obtained three variants of photomodified sgRNA with different photolinker positions. Evidence was obtained showing that the sgRNA with the photolinker introduced in the protein Cas9 site of binding and hairpin formation is able to effectively guide Cas9 nuclease for target DNA cleavage before UV irradiation and lose its activity after irradiation. The conditions of controllable 40% cleavage of a model target DNA were chosen. Conclusions: The work presents the results of photocleavable sgRNA design and usage as a component of photoregulated CRISPR/Cas9 system. The developed approach makes possible specific inactivation of the CRISPR/Cas9 gene editing system in a specific time moment in a definite place. The photoregulation of the gene-editing system not only allows one to reduce undesirable off-target effects, but also forms the basis for genetic disease therapy. [ABSTRACT FROM AUTHOR]

Ballast water (BW) poses the risk of introducing species. Therefore, ships install the ballast water management system (BWMS) to reduce the risks caused by BW. To gain a deeper understanding of the treatment effectiveness of the BWMS, in this study we compared the effectiveness of four different treatment processes of BWMSs on seawater phytoplankton, which were electrochlorination treatment, hydroxyl radical oxidation treatment, membrane separation and deoxygenation treatments, and UV irradiation treatment. The results showed that all four BWMSs had a reduction in phytoplankton density of over 99%. In terms of phytoplankton taxa, the effectiveness of the four BWMSs was different. The taxa removal rates of the four BWMSs were 81.25%, 39.58%, 59.31%, and 74.49%, respectively. Electrochlorination treatment and UV irradiation treatment were significantly more effective than hydroxyl radical oxidation treatment and membrane separation and deoxygenation treatments. The residual phytoplankton taxa were mainly dinoflagellate and diatoms, such as Cucumeridinium, Prorocentrum, Navicula, and Skeletonema. Taxa that can tolerate treatment may be more likely to survive and reproduce. There is still a need to continue to strengthen the development and research on the BWMS in the future to promote the development of BW management. [ABSTRACT FROM AUTHOR]

To improve melt strength and toughness of polyamide 6 (PA6), an on‐line UV radiation method is introduced into reaction extrusion to induce free radical reaction for efficient preparation of long‐chain branched PA6 materials. Trimethylolpropane triacrylate and glycidyl methacrylate are adopted as chain extenders to synergistically introduce long‐chain branches onto PA6 macromolecules. Gel permeation chromatography results show the increase of molecular weight of PA6, implying the successful graft of chain extenders onto molecular chains. Based on rheological measurement results, modified PA6 exhibits better melt strength than pure PA6 owing to a larger storage modulus. The elongation at break and impact strength of modified PA6 at T1G1 are about 5.3 and 2.2 times those of pure PA6, respectively, without sacrificing tensile strength. According to Fourier transform infrared spectroscopy results, we propose reaction mechanisms between trimethylolpropane triacrylate/glycidyl methacrylate and PA6 under on‐line UV radiation. This study offers a practical approach for the efficient preparation of long‐chain branched PA6, thereby broadening the potential applications of the material. Highlights: An on‐line UV radiation method is introduced into reaction extrusion.The melt strength and toughness of polyamide 6 are realized simultaneously at low cost.The synergistic effect mechanism of trimethylolpropane triacrylate and glycidyl methacrylate is proposed.Provides a feasible way to efficiently prepare long‐chain branched polyamide 6. [ABSTRACT FROM AUTHOR]

Objective: Zinc Oxide nanoparticles (ZnO NPs) are used widely in nowadays personal care products, especially sunscreens, as a protector against UV irradiation. Yet, they have some reports of potential toxicity. Silica is widely used to cage ZnO NPs to reduce their potential toxicity. Vitamin C derivative, Magnesium Ascorpyl Phosphate (MAP), is a potent antioxidant that can efficiently protect human skin from harmful impacts of UV irradiation and oxidative stress. The combination of silica coated ZnO NPs and MAP nanovesicles could have potential synergistic protective effect against skin photodamage. Methods: Silica coated ZnO NPs and MAP nanovesicles (ethosomes and niosomes) were synthesized, formulated, and evaluated as topical gels. These gel formulations were evaluated in mice for their photoprotective effect against UV irradiation through histopathology and immuno-histochemistry study. Split-face clinical study was conducted to compare the effect of application of silica coated ZnO NPs either alone or combined with MAP nanovesicles. Their photoprotective action was evaluated, using Antera 3D® camera, for melanin level, roughness index and wrinkles depth. Results: Silica coated ZnO NPs when combined with MAP nanovesicles protected mice skin from UV irradiation and decreased the expression of the proinflammatory cytokines, NF-κB. Clinically, silica coated ZnO NPs, alone or combined with MAP nanovesicles, could have significant effect to decrease melanin level, roughness index and wrinkles depth with higher effect for the combination. Conclusion: A composite of silica coated ZnO NPs and MAP nanovesicles could be a promising cosmetic formulation for skin protection against photodamage signs such as hyperpigmentation, roughness, and wrinkles. [ABSTRACT FROM AUTHOR]

A binary polyaniline/TiO2 and varied weight ratio TiO2/PANI nanocomposite was successfully fabricated as an electrode for energy storage application. The TiO2 nanoparticles were synthesized via manual irradiation system with wavelength 256 nm and power 125 W. Polyaniline/TiO2 was then prepared by in situ polymerizing TiO2 onto aniline monomer. Polyaniline nanofibers are loaded with TiO2 to product core-shell system. The polyaniline/TiO2 nanocomposite were characterized using XRD, XPS, TEM, TGA, CP and LCR measurements. The structure properties were examined by XRD and XPS, which confirmed preparing polyaniline/TiO2 binary nanocomposite. The thermal stability was investigated using TGA and obtained high stability of polyaniline/TiO2 compared with polyaniline, while the electrochemical properties were examined by LCR measurements. The LCR measurements were appeared dielectric constant and dielectric loss for incorporating TiO2 through PANI. Varied weights ratio TiO2 was worked in increasing the stored energy ability of polyaniline. Notably, the electrochemical investigate results appear that the PANI/TiO2 has a high specific capacitance 250 F/g) compared with pure PANI(200 F/g). [ABSTRACT FROM AUTHOR]

Herein, Ag/TiO2/Nylon 6/PMMA catalyst system was developed, and its photocatalytic properties were fully analyzed. XRD, SEM, EDS, and PL analyses were carried out to get information on crystal structure, micromorphology, elemental composition, and band gap energy. Photocatalytic degradation was followed by UV–vis spectrophotometry. The band gap of the catalyst was found to be between 2.51 and 3.1 eV. Up to 80% degradation was achieved under UV light irradiation. No bulk adsorption was observed, which means that the reaction was completely carried by the photocatalytic process. pH 3 value was determined to be suitable for a high rate. Reaction kinetic was determined to be matched with the first-order rate law. The newly developed polymer blend matrix system here may have broad application prospects in the remediation of water resources. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) can be produced safely and greenly using water hyacinth, an invasive aquatic plant, as a reducing agent. This study aimed to optimize the UV-irradiation parameters for the synthesis of AgNPs from water hyacinth leaf extract. The study varied the reaction time and pH levels and added a stabilizing agent to the mixture. The synthesized AgNPs were characterized using UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The findings revealed that the optimal conditions for synthesizing AgNPs were achieved by adjusting the pH level to 8.5, adding starch as a stabilizing agent, and exposing the mixture to UV-A radiation for one hour. These conditions resulted in the smallest size and highest quantity of AgNPs. Furthermore, the synthesized AgNP colloids remained stable for up to six months. This study highlights the potential of utilizing water hyacinth as a sustainable and cost-effective reducing agent for AgNP synthesis, with potential applications in pharmaceuticals, drug development, catalysis, and sensing detection. [ABSTRACT FROM AUTHOR]

The photodegradation of azithromycin present was carried out in water using H2O2 under UV irradiation. The reaction variables considered in this study were the amount of H2O2 solution and the initial concentration of azithromycin to evaluate the performance of the photodegradation process. The azithromycin degradation was not observed in the dark during stirring for 20 min. The study showed an efficient photodegradation of azithromycin using H2O2 as an oxidant in the presence of UV irradiation. The azithromycin degradation was altered significantly by the pH of the irradiated solution. The degradation was low at an acidic pH and showed an increasing trend as the pH changed to basic. The azithromycin degradation increased with a higher amount (higher concentration) of H2O2. The degradation of azithromycin decreased with a higher concentration of azithromycin in the reacting solution. The highest degradation of AZT was achieved in 1 h using a 1.0 ppm AZT solution containing 3 mL of H2O2. The experimental data obtained were well-fitted to zero-order reaction kinetics. The results of this study were found quite excellent. They showed 100% degradation in 1 h when compared with those reported in the literature, both with photocatalysis using nanomaterials and photolysis using light irradiation and/or H2O2. The UV/H2O2 system was found to be quite efficient for the photodegradation of azithromycin, and this system can be applied to degrade other organic pollutants present in industrial wastewater. [ABSTRACT FROM AUTHOR]

Herein, a new, direct paper-based fluorimetric method is described for the quantitative determination of glutathione (GSH) molecules in nutritional supplements. Briefly, the proposed analytical method is based on the fluorescence emission resulting from the direct and selective chemical reaction of GSH molecules with the derivatization reagent that is o-phthalaldehyde (OPA) in acidic conditions at room temperature. The intensity of the emitted fluorescence on the surface of the analytical paper devices after irradiation with a lamp at 365 nm is proportional to the concentration of GSH and is measured using a smartphone as the detector. This methodology, which is suitable for measurements in laboratories with limited resources, does not require specialized instrumentation or trained personnel. The protocol governing the proposed method is simple and easily applicable. Essentially, the chemical analyst should adjust the value of pH on the surface of the paper by adding a minimal amount of buffer solution; then, after adding a few microliters of the derivatization reagent, wait for the surface of the paper to dry and, finally, add the analyte. Subsequently, the irradiation of the sensor and the measurement of the emitted fluorescence can be recorded with a mobile phone. In the present study, several parameters affecting the chemical reaction and the emitted fluorescence were optimized, the effect of interfering compounds that may be present in dietary supplements was examined, and the stability of these paper sensors under different storage conditions was evaluated. Additionally, the chemical stability of these paper devices in various maintenance conditions was studied, with satisfactory results. The detection limit calculated as 3.3 S/N was 20.5 μmol L−1, while the precision of the method was satisfactory, ranging from 3.1% (intra-day) to 7.3% (inter-day). Finally, the method was successfully applied to three different samples of dietary supplements. [ABSTRACT FROM AUTHOR]

Micro-sized particles of synthetic polymers (microplastics) are found in all parts of marine ecosystems. This fact requires intensive study of the degree of danger of such particles to the life activity of hydrobionts and needs additional research. It is evident that hydrobionts in the marine environment are exposed to microplastics modified by biotic and abiotic degradation. To assess the toxic potential of aging microplastic, comparative studies were conducted on the response of cytochemical and genotoxic markers in hemocytes of the mussel Mytilus trossulus (Gould, 1850) after exposure to pristine and photodegraded (UV irradiation) polystyrene microparticles (µPS). The results of cytochemical tests showed that UV-irradiated µPS strongly reduced metabolism and destabilized lysosome membranes compared to pristine µPS. Using a Comet assay, it was shown that the nuclear DNA of mussel hemocytes showed high sensitivity to exposure to both types of plastics. However, the level of DNA damage was significantly higher in mussels exposed to aging µPS. It is suggested that the mechanism of increased toxicity of photo-oxidized µPS is based on free-radical reactions induced by the UV irradiation of polymers. The risks of toxic effects will be determined by the level of physicochemical degradation of the polymer, which can significantly affect the mechanisms of toxicity. [ABSTRACT FROM AUTHOR]

The production of pesticides and its subsequent consumption in agricultural fields have increased significantly also resulting in environmental concerns. The current review discusses the different aspects of two emerging techniques as cavitation and photocatalysis that can be effectively applied for the degradation of toxic pesticides. Governing mechanisms for the degradation have been presented followed by discussion on the effect of different parameters on the extent of degradation, also presenting guidelines for optimum selection. It has been also demonstrated that the obtained degradation can be synergistically intensified by using combined techniques with complimentary mechanisms. The discussion clearly revealed that cavitation and photocatalysis have great potential to degrade pesticides efficiently. Overall, it was demonstrated that combined technique under the optimized set of operating conditions is energy‐efficient, cost‐effective and promising technique for pesticide degradation. [ABSTRACT FROM AUTHOR]

The impact of UV radiation on the high-temperature behavior of polyphenylene sulfide (PPS) fiber was investigated in this study. The ultimate strength, failure strain elasticity modulus and toughness were employed to evaluate the degradation caused by the coupling effects of UV radiation and high temperature. The degradation characteristics of PPS fiber were observed and evaluated based on the scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that both UV exposure and high temperature can effectively reduce the mechanical performance of PPS fiber. The ultimate strength, failure strain and toughness were reduced to the minimum value after UV exposure 150h at room temperature. Both the initial and second elastic modulus of PPS fiber exhibited obvious decreasing trends with the UV exposure time and temperature increasing. The micro defects and molecular structure changes were detected as the degradation characteristics of PPS fiber caused by the coupling effects of UV radiation and high temperature. The Weibull model was applied to quantitatively analyze the dispersion of strength of PPS fiber under extreme conditions.

Clean indoor air is crucial for human lives in residential and workplace settings, including food safety and supply chains. Since the COVID-19 outbreak, disinfecting air has become vital for the public as the SARS-CoV-2 virus and other infectious diseases transmit via inhalable aerosols. Ultraviolet (UV) light is known to be effective in disinfecting air. However, it is still challenging to properly design practical UV applications with common light design software. Visible light analysis software, AGi32, assists architectural applications. AGi32 utilizes digitized luminaire IES files to model light intensity on user-designed geometry in common far-field uses. IES files are based on far-field photometry to model light intensity at different distances and angles from the source. The common application of IES files is to model visible light intensities; however, IES files generated for UV light are still rarely available. Due to the increasing need for surface and air disinfection, modeling UV light intensity using IES files may be beneficial for designing and evaluating systems containing UV light bulbs in near-field applications. There is limited information regarding the accuracy of UV modeling in AGi32 software using IES files. Therefore, the research objectives were to (1) create IES files of a UV-C germicidal lamp (254 nm) and a visible fluorescent lamp with almost identical metrics; (2) compare the IES files output with physical UV measurements inside and outside of an air duct; (3) develop correlations between light intensities of visible and UV light bulbs. Linear correlations were observed when comparing UV irradiance and visible illuminance for both measured and modeled data. The results indicated high variability between the measured and modeled light data, signifying the importance of further investigation of potential error sources and improving the accuracy of modeling.

The accumulation of polyethylene microplastics (PE-MPs) in soil has raised considerable concerns; however, the effects of their persistence and mitigation on agroecosystems have not been explored. This study aimed to assess the detrimental effects of PE-MPs on a soil-plant system and evaluate their mitigation using a novel microbial consortium (MC). We incorporated low-density polyethylene (LDPE) and high-density polyethylene (HDPE) at two different concentrations, along with a control (0 %, 1 %, and 2 % w/w) into the sandy loam soil for a duration of 135 days. The samples were also treated with a novel MC and incubated for 135 days. The MC comprised three bacterial strains (Ralstonia pickettii (MW290933) strain SHAn2, Pseudomonas putida strain ShA, and Lysinibacillus xylanilyticus XDB9 (T) strain S7–10F), and a fungal strain (Aspergillus niger strain F1–16S). Sunflowers were subsequently cultivated, and physiological growth parameters were measured. The results showed that adding 2 % LDPE significantly decreased soil pH by 1.06 units compared to the control. Moreover, adding 2 % HDPE resulted in a more significant decrease in soil electrical conductivity (EC) relative to LDPE and the control. A dose-dependent increase in dissolved organic carbon (DOC) was observed, with the highest DOC found in 2 % LDPE. The addition of higher dosages of LDPE reduced soil bulk density (BD) more than HDPE. The addition of 2 % HDPE increased the water drop penetration time (WDPT) but decreased the mean weight diameter of soil aggregates (MWD) and water-stable aggregates (WSA) compared to LDPE. The results also revealed that higher levels of LDPE enhanced soil basal respiration (BR) and microbial carbon biomass (MBC). The interaction of MC and higher MP percentages considerably reduced soil pH, EC, BD, and WDPT but significantly increased soil DOC, MWD, WSA, BR, and MBC. Regarding plant growth, incorporating 2 % PE-MPs significantly reduced physiological responses of sunflower: chlorophyll content (Chl; −15.2 %), Fv/Fm ratio (-25.3 %), shoot dry weight (ShD; −31.3 %), root dry weight (RD; −40 %), leaf area (LA; −38.4 %), and stem diameter (StemD; −25 %) compared to the control; however, the addition of novel MC considerably reduced and ameliorated the harmful effects of 2 % PE-MPs on the investigated plant growth responses.

Abstract Two low-pressure ultraviolet (UV) lamps at 185/254 nm with sodium persulfate in a pilot UV device were utilized for the degradation of reactive red (B-3BF) dye wastewater compared with two UV lamps at 185/185 nm and two UV lamps at 254/254 nm. The degradation performances of UV irradiation (254/185 nm) with sodium persulfate under different degradation times, flow rates, initial pH, initial Na2S2O8 concentrations and initial dye concentrations were investigated. The experimental results illustrated that the degradation percentage of B-3BF dye could reduce to 90.42% with the energy consumption of 85.1 kWh/kg and the residual dye concentration of 1.92 mg/L by UV irradiation (254/185 nm) with initial Na2S2O8 concentration of 1.5 mmol/L and initial dye concentration of 20 mg/L. In addition, degradation performance of B-3BF dye wastewater by UV irradiation (254/185 nm) with sodium persulfate was more effective than those of UV irradiation (254/254 nm) and UV irradiation (185/185 nm). Therefore UV irradiation (254/185 nm) with sodium persulfate was promising for the degradation of B-3BF dye wastewater.

In this work, ZnO-based powders were synthesized by a simple biosynthesis method using matoa leaf extract and microwave irradiation. The pure ZnO was modified with selenium doping (5, 10 and 15 at.%) to improve the photocatalytic capability in degrading 4-nitrophenol. The synthesized powders had wurtzite structure and XRD analysis demonstrated a change in ZnO lattice parameters with Se doping. Granular surface morphology and decrease in particle size with Se doping were observed by using FESEM. Meanwhile, EDX confirmed the presence of Zn, O and Se elements in the doped samples and BET analysis showed that the specific surface area ranged from 10 to 18m2/g. The observed strong absorption in UV region decreases with Se doping from 367 to 357 nm and is accompanied by an increase in the bandgap energy from 3.14 to 3.23 eV. Under UV irradiation, the ZnO powder doped with 5 at.% Se revealed the highest degrading reaction rate of −0.0218min−1 and photocatalytic efficiency of 88.4% compared to other samples. Therefore, it was shown that an optimal amount of Se and simple biosynthesis route can enhance the photocatalytic capability of ZnO.

Background: Recently, plant-derived exosome-like nanoparticles (PDENs) have been isolated, and active research was focusing on understanding their properties and functions. In this study, the characteristics and molecular properties of ginseng root-derived exosome-like nanoparticles (GrDENs) were examined in terms of skin protection. Methods: HPLC-MS protocols were used to analyze the ginsenoside contents in GrDENs. To investigate the beneficial effect of GrDENs on skin, HaCaT cells were pre-treated with GrDENs (0–2 × 109 particles/mL), and followed by UVB irradiation or H2O2 exposure. In addition, the antioxidant activity of GrDENs was measured using a fluorescence microscope or flow cytometry. Finally, molecular mechanisms were examined with immunoblotting analysis. Results: GrDENs contained detectable levels of ginsenosides (Re, Rg1, Rb1, Rf, Rg2 (S), Gyp17, Rd, C-Mc1, C–O, and F2). In UVB-irradiated HaCaT cells, GrDENs protected cells from death and reduced ROS production. GrDENs downregulated the mRNA expression of proapoptotic genes, including BAX, caspase-1, -3, -6, -7, and -8 and the ratio of cleaved caspase-8, -9, and -3 in a dose-dependent manner. In addition, GrDENs reduced the mRNA levels of aging-related genes (MMP2 and 3), proinflammatory genes (COX-2 and IL-6), and cellular senescence biomarker p21, possibly by suppressing activator protein-1 signaling. Conclusions: This study demonstrates the protective effects of GrDENs against skin damage caused by UV and oxidative stress, providing new insights into beneficial uses of ginseng. In particular, our results suggest GrDENs as a potential active ingredient in cosmeceuticals to promote skin health.

Two low-pressure ultraviolet (UV) lamps at 185/254 nm with sodium persulfate in a pilot UV device were utilized for the degradation of reactive red (B-3BF) dye wastewater compared with two UV lamps at 185/185 nm and two UV lamps at 254/254 nm. The degradation performances of UV irradiation (254/185 nm) with sodium persulfate under different degradation times, flow rates, initial pH, initial Na2S2O8 concentrations and initial dye concentrations were investigated. The experimental results illustrated that the degradation percentage of B-3BF dye could reduce to 90.42% with the energy consumption of 85.1 kWh/kg and the residual dye concentration of 1.92 mg/L by UV irradiation (254/185 nm) with initial Na2S2O8 concentration of 1.5 mmol/L and initial dye concentration of 20 mg/L. In addition, degradation performance of B-3BF dye wastewater by UV irradiation (254/185 nm) with sodium persulfate was more effective than those of UV irradiation (254/254 nm) and UV irradiation (185/185 nm). Therefore UV irradiation (254/185 nm) with sodium persulfate was promising for the degradation of B-3BF dye wastewater. [ABSTRACT FROM AUTHOR]

This study aims to address low starch content in early maturing potato varieties in Heilongjiang Province, seeking to obtain potato varieties with early maturing and high starch content by improvement. In the study, seedlings of Dongnong 303 and Zhonglongshu 1were treated by UV irradiation and ethyl methyl sulfonate(EMS) soaking, and after three years of planting, investigation, and data collection, the effect of mutagenesis methods on the variation degree and mutagenesis direction in different potato varieties was determined. Two high starch mutant plants with excellent traits were screened among the treatments. The results showed that after mutagenesis, the pattern observed was no change > inhibition > promotion, Dongnong 303 was most susceptible to mutation, and UV irradiation had better mutagenesis effective. During tissue culture seeding, most treatments inhibited growth, but during original species, UV irradiation improved yield in Dongnong 303 and increased starch content in Zhonglongshu 1. During protospecies, EMS soaking enhanced the commodity of Dongnong 303. Both methods had a significant inhibitory effect on yield and tuber numbers of Zhonglongshu 1, and the effect of UV irradiation was more significant. Finally, one plant from both of the two varieties showed a significant increase in starch content after the UV treatment. The discovery of the two plants was conducive to mixtured planting of varieties with different maturity in Heilongjiang province, reduced planting risks associated with relying entirely on late maturing varieties, and effectively improved industrial efficiency. [ABSTRACT FROM AUTHOR]

Solar radiation that arrives on the surface of Mars interacts with organic molecules present in the soil. The radiation can degrade or transform the organic matter and make the search for biosignatures on the planet's surface difficult. Therefore, samples to be analyzed by instruments on board Mars probes for molecular content should be selectively chosen to have the highest organic preservation content. To support the identification of organic molecules on Mars, the behavior under UV irradiation of two organic compounds, undecanoic acid and L-phenylalanine, in the presence of vermiculite and two chloride salts, NaCl and MgCl, was studied. The degradation of the molecule's bands was monitored through IR spectroscopy. Our results show that, while vermiculite acts as a photoprotective mineral with L-phenylalanine, it catalyzes the photodegradation of undecanoic acid molecules. On the other hand, both chloride salts studied decreased the degradation of both organic species acting as photoprotectors. While these results do not allow us to conclude on the preservation capabilities of vermiculite, they show that places where chloride salts are present could be good candidates for in situ analytic experiments on Mars due to their organic preservation capacity under UV radiation. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) light is likely to have played important roles in surficial origins of life scenarios, potentially as a productive source of energy and molecular activation, as a selective means to remove unwanted side products, or as a destructive mechanism resulting in loss of molecules/biomolecules over time. The transmission of UV light through prebiotic waters depends upon the chemical constituents of such waters, but constraints on this transmission are limited. Here, we experimentally measure the molar decadic extinction coefficients for a number of small molecules used in various prebiotic synthetic schemes. We find that many small feedstock molecules absorb most at short (∼200 nm) wavelengths, with decreasing UV absorption at longer wavelengths. For comparison, we also measured the nucleobase adenine and found that adenine absorbs significantly more than the simpler molecules often invoked in prebiotic synthesis. Our results enable the calculation of UV photon penetration under varying chemical scenarios and allow further constraints on plausibility and self-consistency of such scenarios. While the precise path that prebiotic chemistry took remains elusive, improved understanding of the UV environment in prebiotically plausible waters can help constrain both the chemistry and the environmental conditions that may allow such chemistry to occur. [ABSTRACT FROM AUTHOR]

Conventional disinfection techniques, relying on a single disinfection step, often fail to directly eliminate microorganisms, instead causing them to enter a viable but nonculturable (VBNC) state. However, microorganisms in the VBNC state retain metabolic activity and can reactivate under suitable conditions, representing a "hidden source of contamination" that threatens drinking water safety. This study fundamentally assessed the feasibility of combined disinfection methods by integrating UV254 with disinfectant (NaClO, PAA, and PDS) for inactivating Pseudomonas aeruginosa (P. aeruginosa), an opportunistic pathogen that has been widely detected in water supply systems. The number of culturable cells was determined using the heterotrophic plate counting (HPC) method, and the number of VBNC cells was quantified using our recently developed qPCR approach. Quantitative analyses showed that combined disinfection methods can effectively reduce both culturable and VBNC cells by several orders of magnitude compared to a single disinfection step. Notably, VBNC P. aeruginosa, after 30 min of UV/NaCIO treatment, was below the detection limit (3.191 log CFU/mL) of PMA-qPCR. The reactivation experiment also confirmed that VBNC P. aeruginosa did not reactivate for 16 h after 30 min of UV/NaClO treatment under controlled laboratory conditions. The higher disinfection capacity of combined methods can be attributed to the generation of reactive radicals. This study highlighted combined disinfection as a promising approach for the inactivation of bacteria in the VBNC state, yet further studies are needed before an application can be considered for minimizing VBNC reactivation in city utility water processing or high-risk building water distribution systems. [ABSTRACT FROM AUTHOR]

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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. [ABSTRACT FROM AUTHOR]

Light assistance and the construction of heterojunctions between two semiconductors with matching band structures are effective strategies for obtaining efficient gas sensors. Recently, Z-scheme heterojunctions have shown marked potential in promoting the separation and transfer of photogenerated carriers as well as possessing strong redox capability. In this study, two types of nanocomposites of WO3/CeO2 and CeO2/WO3 with Z-scheme heterojunctions were designed and prepared with WO3 and CeO2 as host materials, respectively. In the case of the WO3/CeO2 nanocomposite, the CeO2 nanoparticles are evenly distributed and attached to the WO3 host. Conversely, in the CeO2/WO3 nanocomposite, WO3 is completely covered by the CeO2 nanoparticles, forming a core–shell structure. The construction of Z-scheme heterojunctions effectively suppresses the recombination of photogenerated carriers, generates more active sites, and enhances redox capability. Resultantly, under UV light assistance, the sensors based on heterojunctions of WO3/CeO2 and CeO2/WO3 exhibit a selective response toward the oxidizing gas of NO2 and the reducing gas of acetone, respectively, at room temperature. The WO3/CeO2 sensor exhibits a response of 6.82 toward 100 ppb NO2, while the CeO2/WO3 sensor exhibits a response of 6.45 toward 10 ppm acetone at room temperature (RT) under UV irradiation. The dynamic response/recovery characteristics of both heterojunction sensors were improved by UV irradiation, with an obvious shortening of the response/recovery time compared to the case in the dark. The experimental results demonstrate that the two sensors are capable of detecting NO2 and acetone gases at RT, respectively. This work expands the application of Z-scheme heterojunctions in gas sensing and provides a strategy based on the design of special Z-scheme heterojunctions for developing high-performance gas sensors toward selective detection of oxidizing or reducing gas. [ABSTRACT FROM AUTHOR]