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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.

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.

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.

Introducing a groundbreaking solution, a room-temperature (RT, 25 °C) gas sensor addresses complexities in conventional sensors, promising enhanced performance. Synthesized through hydrothermal and thermal calcination processes, SnO2 hollow nanospheres (HNs) are integrated with In2O3 components to bolster sensing capabilities. The sensor detects triethylamine (TEA) gas upon UV light irradiation, owing to its unique surface properties and SnO2–SnO2 and SnO2–In2O3 homo- and heterojunctions. This results in unparalleled sensitivity to TEA gas (Ra/Rg = 34–100 ppm) and an exceptional limit of detection (3.98 ppt), attributed to photo-ionized O2− ions' heightened reactivity. The study proposes superior sensors backed by comprehensive analyses, demonstrating their performance improvements and underlying mechanisms. The optimized sensor design, based on In2O3-appended SnO2 HNs, presents exceptional selectivity, pattern recognition for low TEA gas concentrations, humidity resistance, and reliability under UV irradiation.

In this paper, Al2O3 ceramics co-doped with 0.3 wt%CuO–0.6 wt%TiO2–0.1 wt%MnCO3 (CTM, the same below) were prepared. The effect of CTM and UV irradiation on the sintering behavior, microstructure, and microwave dielectric properties have been investigated systematically. The results indicate that the sintering temperature of Al2O3 ceramics could be effectively decreased to about 1200 °C by adding 1 wt% CTM. UV irradiation can further increase the density of the Al2O3 ceramics, improve its microstructure and microwave dielectric properties. By using the Al2O3 powders UV irradiated for 15 min as raw materials, CTM co-doped Al2O3 ceramics can sintered at 1200 °C with a high density of 3.93 g/cm3 and a very high Q × f value of 175,086 GHz.

Titanium dioxide (TiO2) is a semiconductor material that is frequently utilized in photodegradation applications. Its application in photodegradation is constrained by its broad band gap of 3.2 eV and increased rate of photoelectron recombination. However, by doping TiO2 with metallic nanoparticles, the band gap can be modified and photodegradation can be improved. The present study explores the fabrication of Ag-modified TiO2 nanotube photocatalysts by electrochemical anodization followed by hydrothermal method. The structural, morphological, compositional, optical, and thermal properties of prepared photocatalysts were characterized by X-ray analysis, Field emission scanning electron microscopy, N2 adsorption desorption analysis, X-ray photoelectron spectroscopy, Energy dispersive X-ray spectroscopy, UV–Vis diffuse reflectance analysis and Thermogravimetric-differential thermal analysis. The prepared photocatalyst was utilized to investigate the degradation of methyl violet in the presence of UVA and UVC radiation. The effects of UVA and UVC illumination on the degradation process, the effect of Ag loading in the TiO2 nanotube arrays and the role of H2O2 in the degradation of pollutant were studied. The degradation efficiency of methyl violet in the presence of UVC light was three times that of UVA light. For pristine TiO2 photocatalyst, the maximum degradation of 70% was obtained under UVC illumination in 8 h. When H2O2 was added, complete degradation was observed within 3 h. Reusability studies have shown that photocatalysts are stable and can be used for the degradation of methyl violet.

Introduction: During changeover in cell-product processing, it is essential to minimize cross-contamination risks. These risks differ depending on the patient from whom the cells were derived. Human error during manual cell-product processing increases the contamination risk in biosafety cabinets. Here, we evaluate the risk of cross-contamination during manual cell-processing to develop an evidence-based changeover method for biosafety cabinets. Methods: Contaminant coverage was analyzed during simulated medium preparation, cell seeding, and waste liquid decanting by seven operators, classified by skill. Environmental bacteria were surveyed at four participating facilities. Finally, we assessed the effect of conventional UV irradiation in biosafety cabinets on bacteria and fungi that pose a cross-contamination risk. Results: Under simulated conditions, scattered contamination occurred via droplets falling onto the surface from heights of 30 cm, and from bubbles rupturing at this height. Visible traces of contaminants were distributed up to 50 cm from the point of droplet impact, or from the location of the pipette tip when the bubble ruptured. In several facilities, we detected Bacillus subtilis, of which the associated endospores are highly resistant to disinfection. Irradiation at 50 mJ/cm2 effectively eliminated Bacillus subtilis vegetative cells and Aspergillus brasiliensis, which is highly resistant to UV. Bacillus subtilis endospores were eliminated at 100 mJ/cm2. Conclusions: Under these simulated optimal conditions, UV irradiation successfully prevents cross-contamination. Therefore, following cell-product processing, monitoring the UV dose in the biosafety cabinet during cell changeover represents a promising method for reducing cross-contamination.

Combinations of different materials can improve the functionality of a composite. Heterogeneous structures that consist of various crystalline phases in a single material may also improve the physical and catalytic properties. In this work, we have synthesized highly crystalline CdS with cubic, hexagonal, and heterogeneous phases through precipitation, followed by varying the annealing temperature. The photocatalytic degradation was performed on aqueous rhodamine 6G (R6G) dye as a model pollutant under UV irradiation. From the results, UV–Vis analysis revealed that the heterogeneous structure yields the most intense absorption with a reduced band gap, which is useful for improved photocatalytic reactions. The SEM image demonstrates that the heterogeneous CdS contains more tiny granule particles that disperse extensively over the surface. As a consequence, heterogeneous CdS shows enhanced photocatalytic degradation efficiency and rate constant, which may serve as a future photocatalyst for wastewater remediation.

Background: In addition to its use as a health food, ginseng is used in cosmetics and shampoo because of its extensive health benefits. The ginsenoside, Rh2, is a component of ginseng that inhibits tumor cell proliferation and differentiation, promotes insulin secretion, improves insulin sensitivity, and shows antioxidant effects. Methods: The effects of Rh2 on cell survival, extracellular matrix (ECM) protein expression, and cell differentiation were examined. The antioxidant effects of Rh2 in UV-irradiated normal human dermal fibroblast (NHDF) cells were also examined. The effects of Rh2 on mitochondrial function, morphology, and mitophagy were investigated in UV-irradiated NHDF cells. Results: Rh2 treatment promoted the proliferation of NHDF cells. Additionally, Rh2 increased the expression levels of ECM proteins and growth-associated immediate-early genes in ultraviolet (UV)-irradiated NHDF cells. Rh2 also affected antioxidant protein expression and increased total antioxidant capacity. Furthermore, treatment with Rh2 ameliorated the changes in mitochondrial morphology, induced the recovery of mitochondrial function, and inhibited the initiation of mitophagy in UV-irradiated NHDF cells. Conclusion: Rh2 inhibits mitophagy and reinstates mitochondrial ATP production and membrane potential in NHDF cells damaged by UV exposure, leading to the recovery of ECM, cell proliferation, and antioxidant capacity.

Ammonia (NH3), as main industrial gas emissions, are extremely harmful to the human beings. So the detection of NH3 concentrations in special environments at room temperature (25 °C) is essential. Herein, the composite MXene Ti3C2Tx-TiO2-CuO was successfully prepared by one-step in-situ oxidation method using Cu(NO3)2·6H2O as a precursor. The morphology of Ti3C2Tx-TiO2-CuO shows layered accordion-like structure. Ti3C2Tx-TiO2-CuO sensor exhibits improved NH3 gas sensing response of 56.9 toward 100 ppm NH3 at room temperature under ultraviolet (UV) light exposure, which is 89.8 % higher than that of pristine Ti3C2Tx material. The improved gas sensing performance is attributed to the irradiation of UV light, the retention of Ti3C2Tx layered structure and the construction of TiO2-CuO heterojunction. Further, the possible gas sensing mechanism of the material was proposed and discussed.

Nano-crystalline titanium dioxide (TiO2) photocatalyst has been extensively utilized in the last few decades because of its strong oxidizing power, redox selectivity, and higher photocatalytic performance. In this work, TiO2 nanoparticle (NPs) was synthesized, characterized, and applied for the degradation of methyl orange (MO) dye in an aqueous solution under UV and solar light irradiations. The XRD results showed dominated anatase phase (82%) with a smaller crystalline size (18.23 nm). A rough surface with a uniform spherical shape was observed by SEM analysis. FTIR and UV–Vis/DRS spectroscopy confirmed the stretching vibration of the hydroxyl groups and higher absorption edge towards longer wavelength with smaller bandgap energy (3.12 eV) of TiO2 lattice structure. The activity of TiO2 NPs was carried out from the degradation of MO dye as a model contaminant for textile effluent in presence of UV/solar irradiation. The photodegradation efficiency of MO dye (15 mg L−1) was observed at 85.90% and 96.38% for 0.150 g and 0.030 g of TiO2 NPs at natural pH (7.0), after 5 h of UV and solar light irradiation. The respective rate constants were determined to be 0.0063 min−1 and 0.01 min−1 for UV and simulated solar light irradiation respectively, and exhibited the best-fitted kinetic model of pseudo-first-order. The photodegradation efficiency was increased with the decrease of pH, while efficiency decreased with an increase in initial dye concentration. The obtained result from TiO2 NPs was compared with commercially available Degussa P25 catalyst. The photocatalyst reusability test and reaction mechanism were also evaluated. The study suggests that TiO2 NPs are a promising photocatalyst that can be used for the degradation of organic dye compounds from textile wastewater towards the sustainable management of environment.

In this study, we evaluated the photostability of a cocrystal of naproxen (NPX) and nicotinamide (NA) for the development of the photostabilization strategy. NPX photodegradation during ultraviolet-light (UV) irradiation was estimated by high-performance liquid chromatography (HPLC). The photostability of a NPX-NA cocrystal was less than NPX in the solid-state. Furthermore, NPX was photodegraded faster in the presence of NA at a higher concentration when the NPX-NA mixtures were UV-irradiated. The values of residual amounts of NPX in UV-irradiated NPX-NA cocrystal and mixture were 76.60 ± 3.85% and 70.06 ± 4.09%, respectively, which were significantly lower compared with that of UV-irradiated NPX powder (83.57 ± 2.15%). However, in the case that the effect of NA in the suspension of NPX was investigated, NA had no effect on NPX photodegradation. Residual amounts of NPX in UV-irradiated suspensions of NPX and NPX-NA cocrystal were comparable (33.13 ± 6.02% and 30.22 ± 2.09%, respectively). These results suggested that NA might promote NPX photodegradation only in the solid-state on account of that NA molecule could deliver the excitation energy to NPX molecule. This is the first study focused on the photochemical behavior of NPX-NA cocrystal and mixture and suggests that the presence of NA might induce the change of photostability of NPX in the powder form.

Perovskite-structured materials are used as gas-sensitive materials due to their wide bandgap and controllable morphology, but large initial resistance and low response limit their development. In this work, ZnSn(OH) 6 /ZnO composites derived from ZnO were synthesized by hydrothermal method. The gas-sensitive results show that all sensors show significantly improved response to NO 2 under UV irradiation compared with without UV irradiation. Notably, under UV irradiation the operating temperatures of sensors are reduced from 110 °C to room temperature and have a low initial resistance. Compared with bare ZnO, the ZnSn(OH) 6 /ZnO-7 sensor shows a 4.4-fold improvement in response to 10 ppm NO 2 under UV irradiation at room temperature and has response/recovery time (54.5/74 s). Meanwhile, the ZnSn(OH) 6 /ZnO-7 sensor has a practical detection limit of 50 ppb and a theoretical detection limit of 9.86 ppb, which enable efficient detection of trace NO 2 . The excellent gas-sensitive performance of the ZnSn(OH) 6 /ZnO sensors can be attributed to the highly efficient photogenerated carrier separation efficiency, the special morphology, high oxygen vacancy content and the construction of numerous heterostructures. Therefore, the ZnSn(OH) 6 /ZnO sensors provide insights into the realization of high-performance perovskite-structured NO 2 sensors under UV irradiation at room temperature., Competing Interests: Declaration of competing interest All authors’ intention is to publish in the TALANTA. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The design of biocomposite structures for outdoor applications should consider the influence of ultraviolet (UV) irradiation on the mechanical performances to more accurately determine their durability characteristics and prevent significant damage. Ultraviolet radiation causes the discoloration, surface roughness, mass loss, and degradation of the mechanical properties of biocomposites. In this study, the flexural strength and low-velocity impact response of polypropylene reinforced with short flax or pine fibers, which differed with respect to their physical and chemical properties, were investigated. Flax fibers are twice the length of pine fibers, and exhibit higher cellulose contents. Moreover, flax fibers have been demonstrated to increase the flexural strength and impact resistance of biocomposites. However, under UV irradiation, pine fibers containing more lignin dampened the degradation. Under photo-oxidative conditions, lignin is degraded to protect crystalline cellulose by acting as a light-absorbing compound. Non-destructive techniques such as Fourier transform infrared spectroscopy (FTIR), colorimetry, confocal imaging, acoustic emission, and CT scanning were therefore used to evaluate the effect of UV radiation on the chemical properties, color change, surface roughness, bending behavior, and drop-impact damage.

Pterygium pathogenesis is often attributed to a population of altered limbal stem cells, which initiate corneal invasion and drive the hyperproliferation and fibrosis associated with the disease. These cells are thought to undergo epithelial to mesenchymal transition (EMT) and to contribute to subepithelial stromal fibrosis. In this study, the presence of the novel limbal stem cell marker ABCB5 in clusters of basal epithelial pterygium cells co-expressing with P63α and P40 is reported. ABCB5-positive pterygium cells also express EMT-associated fibrosis markers including vimentin and α-SMA while their β-catenin expression is reduced. By using a novel in vitro model of two-dose UV-induced EMT activation on limbal epithelial cells, we could observe the dysregulation of EMT-related proteins including an increase of vimentin and α-SMA as well as downregulation of β-catenin in epithelial cells correlating to downregulation of ABCB5. The sequential irradiation of limbal fibroblasts also induced an increase in vimentin and α-SMA. Taken together, these data demonstrate for the first time the expression of ABCB5 in pterygium stem cell activity and EMT-related events while the involvement of limbal stem cells in pterygium pathogenesis is exhibited via sequential irradiation of limbal epithelial cells. The later in vitro approach can be used to further study the involvement of limbal epithelium UV-induced EMT in pterygium pathogenesis and help identify novel treatments against pterygium growth and recurrence.

Objectives: Due to the surge in demand for N95 masks during the Covid-19 pandemic, and considering the situation in countries grappling with acute shortages of N95 masks, this study investigated the possibilities of decontamination and reuse of masks. Methods: Three N95 masks of different makes (A, B and C) were subjected to six decontamination methods: ultraviolet (UV) irradiation, isopropyl alcohol (IPA) dip, plasma sterilization (Sterrad®), ethylene oxide (ETO, 3M®), dry heat sterilization, and moist heat sterilization (autoclaving). The integrity of the N95 masks was assessed by measuring their particle filtering efficiency at particle sizes ranging 0.3–0.5 microns. Results: All the masks decontaminated with ETO and plasma sterilization retained over 95% particle filtering efficiency. Masks decontaminated using IPA dip and autoclaving showed a drop, and UV irradiation showed variations in particle size efficiency degradation after decontamination. Conclusions: Plasma sterilization is recommended for decontamination of N95 masks in low-resource settings. ETO is not recommended due to hazards associated with handling of ethylene oxide, although the filtering efficiency was retained. Since the UV irradiation method showed variations in results, evaluation of UV decontamination for N95 masks needs to be performed on a case-by-case basis.

This study investigates the photophysical and electrical properties of 4-heptamethyl-trisiloxanyl-n-undecyloxy-4'-nitrostilbene (SNS), a low molar mass organosiloxane liquid crystal containing a nitrostilbene chromophore. Real-time monitoring of the absorption and fluorescence spectra of the nitrostilbene moiety was conducted in dichloromethane solution and thin films (in both crystalline and Smectic C (SmC) phases). A charge transfer excited state is formed following vibrational cooling and solvent interaction within 0.4 to 1.6 ps, which then relaxes to the ground state in 1.6 ns. Five distinct lifetime components were identified in thin films, attributed to the heterogeneous local environment and aggregate formation. Notable differences in excited-state lifetimes were observed between the crystalline and SmC phases, with slower dynamics in the former due to the rigidity of the crystalline phase. Photoconductivity under UV irradiation was examined in SmC, Smectic A (SmA), and isotropic phases, showing a significant increase in current response, particularly in the SmC phase. Polarizing optical microscopy revealed morphological changes post-UV exposure, such as reduced SmC domain size and decreased birefringence. Dielectric measurements indicated distinct relaxation peaks in SmC and SmA phases, reflecting more disordered molecular arrangements. The study reveals that UV exposure significantly enhances SNS conductivity, particularly within the SmC phase. This enhancement is likely attributed to UV excitation promoting the formation of an intramolecular charge transfer state within the trans-stilbene moiety. These findings provide valuable insights into the potential applications of nitrostilbene-functionalized organosiloxane liquid crystals in optoelectronic devices, such as light switches and photodetectors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

ZnO nanowires were prepared by oxidized ZnS nanowires. The sensing performance of these ZnO nanowires for NO2 gas was enhanced by decorating Au nanoparticles on their surface. The scanning electron microscopy results revealed that diameter and length of the ZnO nanowires showed 150–200 nm and up to a few hundreds of μm, respectively. The diameters of Au nanoparticles which were decorated on the ZnO nanowires were 5–20 nm and they were distributed evenly on the surface of the nanowires. The transmission electron microscopy results revealed that the ZnO nanowires obtained after 2 h of the oxidation treatment process were composed of lots of nanograins with a diameter of 50–100 nm, which rendered the surface of the nanowires rough and full of void spaces. The hierarchical structure of the nanowires increased their surface-to-volume ratio and contributed to the adsorption of gas on their surface, improving their sensing performance. In this study, the NO2 gas sensing mechanism of the Au nanoparticle-decorated ZnO nanowires sensors were investigated under UV illumination at room temperature.

Background: 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., Objective: We investigated changes in CRAT expression upon UV irradiation and its effect on MMP-1 expression., Methods: 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., Results: 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., Conclusion: CRAT downregulation caused by promoter hypermethylation may play an important role in UV-induced skin aging via upregulation of MMP-1 expression., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2024 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

Water-soluble polyacrylamide (PAM) compounds have been used extensively in various sectors. The abundance of PAM in the environment raises concerns about its environmental impact. However, the mineralization of PAM in water under natural light irradiation remains insufficiently explored. This study utilizes nonionic PAM (nPAM) as a representative model to investigate both the mechanism and efficiency of nPAM degradation in water when exposed to ultraviolet (UV) light with hydrogen peroxide (H 2 O 2 ) as the hydroxyl radical source. In the dark or with only UVA irradiation, negligible mineralization of nPAM occurred. In contrast, the presence of hydroxyl radicals (produced by the UVA/H 2 O 2 system) produced 50 % nPAM mineralization over 7 days under our experimental conditions. The corresponding molecular weight (MW) of the nPAM was swiftly reduced from 1.58 ×10 6 Da to 1.59 ×10 3 Da in 3 days. Moreover, five carboxylic acids and nitrate ions were identified as the photodegradation intermediates of nPAM. The efficiencies of nPAM photodegradation by the UVA/H 2 O 2 system in different natural waters and environmental conditions were assessed. The rate constant for the reaction between the hydroxyl radical and nPAM was 2.17 ×10 9 M-unit -1  s -1 . The half-lives of nPAM in the sea and continental surface waters were determined to be several years and dozens of days, respectively. The application of UVB obviously accelerated the mineralization of nPAM in ultrapure water (71 % degradation in 7 days). Moreover, mineralization of concentrated nPAM (200 mg/L) in sea water was more efficient when both UVA- and UVB-activated H 2 O 2 were used. Additionally, toxic acrylamide was not generated during nPAM photodegradation. Moreover, the photodegradation intermediates from nPAM were found to be neither acutely nor chronically toxic to aquatic organisms. This comprehensive study sheds light on the photochemical fate of nPAM in natural waters and provides essential insight for practical treatment of PAM in water systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

As one of the most powerful approaches to mechanistically understanding complex chemical reactions and performing simulations or predictions, kinetic modeling has been widely used to investigate advanced oxidation processes (AOPs). However, most of the available models are built based on limited systems or reaction mechanisms so they cannot be readily extended to other systems or reaction conditions. To overcome such limitations, this study developed a comprehensive model on phenol oxidation using over 540 reactions, covering the most common reaction mechanisms in nine AOPs—four peroxymonosulfate (PMS), four peroxydisulfate (PDS), and one H2O2 systems—and considering product formation and the effects of co-existing anions (chloride, bromide, and carbonate). Existing models in the literature were first gathered and then revised by correcting inaccurately used reactions and adding other necessary reactions. Extensive model tuning and validation were next conducted by fitting the model against experimental data from both this study and the literature. The effects of anions were found to follow PDS/CuO > H2O2/UV > other PDS or PMS systems. Halogenated organic byproducts were mainly observed in the PMS systems in the presence of halides. Most of the 543 reactions were found to be important based on the sensitivity analysis, with some anions-involved reactions being among the most important, which explained why these anions substantially altered some of the reaction systems. With this comprehensive model, a deep understanding and reliable prediction can be made for the oxidation of phenol (and likely other phenolic compounds) in systems containing one or more of the above AOPs.

Thin films of transparent conductive Al doped ZnO (AZO) thin films were produced via sol-gel spin coating route. Structural, optical, and electrical properties were explored for several dopant concentrations. Formation of crystalline AZO was verified by X-ray Diffraction (XRD) Analysis and structural analysis were carried out later from the XRD data. Highest band gap of 3.67 eV was found for 2 mol % AZO thin films. The average transmittance was found to be 84.19% in the visible spectra for the corresponding thin films. 2 mol% AZO also exhibited a minimum resistivity of 2.05 Ω-cm with a maximum value of figure of merit. Prolonged UV irradiation was applied to 2 mol % AZO thin films prior to annealing. It significantly modified the surface morphology of the film and provided shielding near UVA (315–378 nm) spectrum. This also enhanced the conductivity of the thin film by 3-fold compared to non-UV treated sample and decreased optical band gap significantly.

Diseases represent a major threat for the bivalve production industry. Their control relies on biosecurity measures to prevent their introduction and limit their spread. When maintained in hatcheries, nurseries and depuration centers, bivalves can become infected from the surrounding water and might release pathogens through wastewater effluents. A major effort was done in controlling the safety of bivalves for human consumption, but, on the other hand, information regarding the resistance of mollusc pathogens to water treatment is scarce. The effect of ultraviolet exposure was tested on two protozoan parasites of marine bivalves, the non-culturable parasite Bonamia ostreae and Perkinsus olseni culturable in DMEM/HAM´s medium. UV exposure experiments were carried out first at the bench scale and then, for P. olseni, at a larger scale mimicking depuration plants, hatcheries and nurseries conditions. At the bench scale, our study indicated that up to 40% of B. ostreae cells and 85% of P. olseni cells died 24 h and 21 days respectively after an exposure to 94 mJ/cm2 of UV-C. After 40 mJ/cm2 exposure, P. olseni density increased between 15 and 21 days of culture suggesting that the parasite is able to recover from low UV intensity exposure. At large scale, no signs of UV recovery were seen in P. olseni cultures, but, at lower intensity (216–244 mJ/cm2), 15% of the parasites remained alive 21 days post exposure. Finally, a minimum dose of 94 mJ/cm2 seems required to inhibit proliferation of parasites and 450 mJ/cm2 to completely kill all parasites. Taken this into account, a dose higher than 450 mJ/cm2 is suggested to properly treat water to avoid dispersion of bivalve protozoan parasites such as P. olseni.

Dibutyl phthalate (DBP) as a plasticizer has been widely used in the processing of plastic products. Nevertheless, these DBP additives have the potential to be released into the environment throughout the entire life cycle of plastic products. Herein, the leaching behavior of DBP from PVC microplastics (MPs) in freshwater and seawater and its potential risks were investigated. The results show that the plasticizer content, UV irradiation, and hydrochemical conditions have a great influence on the leaching of DBP from the MPs. The release of DBP into the environment increases proportionally with higher concentrations of additive DBP in MPs, particularly when it exceeds 15 %. The surface of MPs undergoes accelerated oxidation and increased hydrophilicity under UV radiation, thereby facilitating the leaching of DBP. Through 30 continuous leaching experiments, the leaching of DBP from MPs in freshwater and seawater can reach up to 12.28 and 5.42 mg g -1 , respectively, indicating that MPs are a continuous source of DBP pollution in the aquatic environment. Moreover, phthalate pollution index (PPI) indicates that MPs can significantly increase DBP pollution in marine environment through land and sea transport processes. Therefore, we advocate that the management of MPs waste containing DBP be prioritized in coastal sustainable development., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Based on the fact that not all chemical substances possess good Raman signals, this article focuses on the Raman silent region signals of pesticides with cyano group. Under the optimized conditions of methanol-water (1:1, v/v) as the solvent, irradiation at 302 nm light source for 20 min, and the use of 0.5 mol/L KI as the aggregating agent, Surface-enhanced Raman spectroscopy (SERS) method for azoxystrobin detection was developed by the Raman silent region signal of 2230 cm -1 , and verified by detecting the spiked grapes with different concentrations of azoxystrobin. Other four pesticides with cyano group also could be identified at the peak of 2180 cm -1 , 2205 cm -1 , 2125 cm -1 , and 2130 cm -1 for acetamiprid, phoxim, thiacloprid and cymoxanil, respectively. When azoxystrobin or acetamiprid was mixed respectively with chlorpyrifos without cyano group, their SERS signals in the Raman silent region of chlorpyrifos were not interfered, while mixed with cymoxanil in different ratios (1:4, 1:1 and 4:1), respectively, each two pesticides with cyano group could be distinguished by the changes in the Raman silent region. In further, four pesticides with or without cyano group were mixed together in 1:1:1:1 (acetamiprid, cymoxanil, azoxystrobin chlorpyrifos), and each pesticide still could be identified even at 0.5 mg/L. The results showed that the SERS method combined with UV irradiation may provide a new way to monitor the pesticides with C≡N performance in the Raman silent region without interference from the food matrix., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The prevalence of plastics in the oceans has significantly intensified microplastic pollution, contributing to broader marine secondary pollution issues. This paper examines how plastic structure affects the aging characteristics of plastics and the release of metal ions, to better understand this secondary source of marine pollution. This study simulate the photoaging of plastics in natural environments, focusing on aliphatic and aromatic polymers. The results showed that the photodegradation degree was higher for aliphatic than aromatic polymers. All polymers contained thirteen detectable metals, with their release increasing over time due to photoaging, The release dynamics of these metal ions correlated more strongly with the level of polymer degradation rather than with the polymer structure itself, adhering to a second-order kinetic model driven by surface and intraparticle diffusion processes. The results will help control and treat marine plastic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

We have previously found that UV irradiation promotes RNA polymerase II (RNAPII) hyperphosphorylation and subsequent changes in alternative splicing (AS). We show now that UV-induced DNA damage is not only necessary but sufficient to trigger the AS response and that photolyase-mediated removal of the most abundant class of pyrimidine dimers (PDs) abrogates the global response to UV. We demonstrate that, in keratinocytes, RNAPII is the target, but not a sensor, of the signaling cascade initiated by PDs. The UV effect is enhanced by inhibition of gap-filling DNA synthesis, the last step in the nucleotide excision repair pathway (NER), and reduced by the absence of XPE, the main NER sensor of PDs. The mechanism involves activation of the protein kinase ATR that mediates the UV-induced RNAPII hyperphosphorylation. Our results define the sequence UV-PDs-NER-ATR-RNAPII-AS as a pathway linking DNA damage repair to the control of both RNAPII phosphorylation and AS regulation.

Esterification of citric acid (CA) with locust bean gum (LBG) was prepared by hydrochloric acid (HCl) as a catalyst and UV irradiation (254 nm) as esterification energy. This study aims to determine the best conditions of esterification. Other than that, it is to know the effect of amount HCl and UV irradiation time for the esterification process of CA with LBG. The amounts of HCl are 0.18 and 0.30 M, while the variations of UV irradiation time are 75 and 100 minutes. Polyester (CA-LBG) were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffractometer (XRD), esterification degree, and viscosity. Parameters for determining the best conditions for esterification are esterification degree and viscosity. The best conditions of esterification were obtained by using 0.30 M mL HCl and 100 minutes of UV irradiation time resulted in CA-LBG having a value of esterification degree 9.69 % and viscosity 7.46 cPs. HCl accelerates protonation on the O atoms and the formation of positive C atoms of carbonyl groups of citric acid. The time of UV irradiation gives the longer energy for the bond formation between the positive C atoms of the carbonyl group and the O atoms of the hydroxyl group at C-6 atoms of mannose and galactose.

Decomplexation of Cu(II)-EDTA followed by chemical precipitation of free Cu(II) ions can effectively degrade EDTA in Cu(II)-EDTA and remove Cu(II), but requires large precipitant dosage and inevitably produces a large amount of copper-containing sludge that is difficult to deal with. Herein, we demonstrated that simultaneous reduction of Cu(II) and degradation of EDTA in Cu(II)-EDTA can be achieved by UV irradiation of wastewater containing Cu(II)-EDTA without adding reagent. 93.65% of Cu(II) was reduced to Cu(0) with a high purity of 99.93 wt%, which can be recycled, thus avoiding the generation of copper-containing sludge. 96.67% of EDTA in Cu(II)-EDTA was degraded, and the final products were HCHO, NH 4 + , NO 3 - produced by UV irradiation of Cu(II)-EDTA. This study provided an approach of simultaneous removal of heavy metals and degradation of EDTA in Cu(II)-EDTA in wastewater containing heavy metal-EDTA complex.2 -COOH group, followed by ligand to metal charge transfer (LMCT) and hydrolysis reactions. The minor degradation mechanism of EDTA in Cu(II)-EDTA was successive decarboxylation by •OH radicals. Simultaneously, Cu(II) was reduced to Cu(0) by H• and e aq - produced by UV irradiation of Cu(II)-EDTA. This study provided an approach of simultaneous removal of heavy metals and degradation of EDTA in Cu(II)-EDTA in wastewater containing heavy metal-EDTA complex., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The TiO2/ZnO nanocomposite as a photocatalyst was prepared with different molar ratios of ZnO using the sol–gel method. The structures and properties were recognized with Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The XRD study exhibited that the crystallization behavior of the nanocomposites was associated with the molar ratios of ZnO. The SEM images indicated that with increasing the molar ratio of TiO2/ZnO until 50:10, regular morphology can be seen. It should be of interest for catalytic purposes since it expectantly improves the surface area. Furthermore, the photocatalytic activity of the synthesized nanocomposites was investigated for decolorization of Methylene Blue (MB) in water under UV irradiation in a batch reactor. The results revealed that the photocatalytic activity of nanocomposite with 50:10 M ratio of TiO2/ZnO was the best.

Four-hydroxy-3-aminophenylarsonic acid (HAPA), the reduced product of roxarsone (4-hydroxy-3-nitro-phenylarsonic acid, ROX) under anaerobic conditions, is resistant to be biologically degraded under anaerobic/anoxic conditions. The transformation of HAPA in aquatic environment under sunlight irradiation is still unknown. In this study, the photodegradation of HAPA and the possible mechanism under simulated sunlight conditions were investigated. The result shows that under visible light irradiation, HAPA wasn't degraded. Under UV 254 and UV 302 irradiation, about 60% and 30% HAPA were decomposed, while nearly no HAPA was degraded under UV 365 irradiation over a period of 240 min. UVC light was the main wavelength for the degradation of HAPA under sunlight conditions. HCO 3 - and NO 3 - slightly enhanced the photodegradation, but Cl - and SO 4 ) has little influence on the decomposition of HAPA under UV irradiation, but significantly enhanced the conversion of As(III) to arsenate (As(V)).2- had a marginal influence on the photodegradation. During the photodegradation, HAPA was decomposed into organic intermediates, inorganic arsenics, ammonia and undetermined arsenic species. Arsenite (As(III)) was the dominant inorganic arsenic species from the photodegradation of HAPA. The mechanism analysis shows that singlet molecular oxygen ( 1 O 2 ) has little influence on the decomposition of HAPA under UV irradiation, but significantly enhanced the conversion of As(III) to arsenate (As(V))., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Microplastic (MP) pollution is a global environmental problem. To understand the biological effects of MPs on humans, it is essential to evaluate the response of human cells to model plastic particles that mimic environmental MPs in a sensitive and non-invasive manner. In this study, we investigated the preparation of poly(ethylene terephthalate) (PET) fragments with properties similar to those of environmental MPs by combining photo-oxidative degradation via ultraviolet (UV) irradiation with mechanical pulverization and hydrolysis via ultrasound (US) exposure. Combination of UV and US treatments decreased the particle size of PET fragments to 10.2 µm and increased their crystallinity and Young's modulus to 35.7 % and 0.73 GPa, respectively, while untreated PET fragments showed the particle size of 18.9 µm, the crystallinity of 33.7 %, and Young's modulus of 0.48 GPa. In addition, an increase in negative surface potential and O/C ratio were observed for UV/US-treated PET fragments, suggesting surface oxidation via UV/US treatment. Cytokine secretion from human macrophages was evaluated by a highly sensitive inflammation evaluation system using the HiBiT-based chemiluminescence detection method developed by genome editing technology. UV/US-treated PET fragments induced a 1.4 times higher level of inflammatory cytokine secretion on inflammatory macrophages than untreated ones, suggesting that the biological responses of PET fragments could be influenced by changes in material properties via oxidation. In conclusion, UV/US treatment enables efficient preparation of model plastic particles and is expected to provide new insights into the evaluation of biological effects using human cells. (240 words)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Polythiophene (PTh) has been the subject of considerable interest because of its good environmental stability, unique redox electrical behavior, stability in doped or neutral states, ease of synthesis, and wide range of applications in many fields. Apart from its applications in the electrical or electronic field, PTh has shown promising applications in photocatalytic degradation. The fabrication of a catalyst, metal oxides with PTh, extends the absorption range of the modified composite system, thereby enhancing the photocatalytic activity under UV or visible light irradiation. Substituted PTh, such as alkyl substitution, modifies the electronic properties of the polymer, thereby enlarging the potential for industrial applications. PTh or substituted PTh when combined with metal, metal oxide or a combination of both, can exhibit tailorable photocatalytic properties. This review focuses on the chemistry of the band gap engineering of PTh or PTh based systems and the mechanism of photocatalytic degradation. The major developments in the field of UV and visible light-assisted photocatalysis are discussed in terms of the parameters that affect the photocatalytic efficiency. On the other hand, some challenges still needs to be investigated experimentally, which are mentioned as the scope for future studies. For simplicity, the review has been classified under a major subheading depending on the type of composite system used for photocatalysis.

During the COVID-19 pandemic, UV-C germicidal lamps became widely available, even for household applications. However, their long-term degradation effects on the mechanical and rheological properties of polylactic acid (PLA) are still not well established. The relationship between degradation and its effects on the molecular structure and macroscale properties are hardly known. In this study, we investigated the effects of long-term exposure to UV-C irradiation on the properties of PLA and interpreted the results at the molecular scale. We performed gel permeation chromatography, Fourier-transform infrared spectroscopy and UV-Vis spectroscopy to analyse changes in chemical structure induced by the UV-irradiation. Then, we carried out thermal, rheological and tensile tests to investigate mechanical and melting properties, and we investigated the applicability of these test results to estimate molecular weight loss. We have created a 3D irradiation map that can facilitate the design of disinfection devices. Based on our results, we propose a maximum number of sterilisation cycles (13 cycles) for the tested PLA films that do not result in significant changes in tensile strength and modulus., Competing Interests: Declaration of competing interest Kolos Molnár reports financial support was provided by National Research Development and Innovation Office. Ábris Dávid Virág reports financial support was provided by Ministry for Culture and Innovation. Kolos Molnár reports financial support was provided by European Union., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Polyethersulphone (PES) membranes have been widely applied in various separation applications such as microfiltration, ultrafiltration and nanofiltration. This has occurred as these membranes are easy to form, have good mechanical strength and good chemical stability (resistant to acidic or alkaline conditions) due to the presence of aromatic hydrocarbon groups in the structure. PES membranes are commonly fabricated through the phase inversion method due to the simplicity of the process. However, PES membranes are generally hydrophobic, which usually requires them to be modified before application. In most cases, these methods can reduce the hydrophobicity of the membrane surface and thus reduce membrane fouling during application. This review will further discuss the recently developed UV-induced modifications of PES membranes. The UV-induced grafting method is easy to apply to existing PES membranes, with or without the need for a photo-initiator. Additionally, nanoparticles entrapped in PES membranes subsequently exposed to UV-irradiation have been reported to possess photo-catalytic activity. However, UV-irradiation methods still require special care in order to produce membranes with the best performance.

Exposure to ultraviolet (UV) light can cause skin photoaging, which is associated with upregulation of matrix metalloproteinases (MMPs) and downregulation of collagen synthesis. It has been reported that MMPs, especially MMP-1, MMP-3 and MMP-9, decrease the elasticity of the dermis by degrading collagen. In this study, we assessed the effects of Pinus densiflora extract (PDE) on photoaging and investigated its mechanism of action in human skin fibroblast (Hs68) cells after UVB exposure using real-time polymerase chain reaction, Western blot analysis, and enzymatic activity assays. PDE exhibited an antioxidant activity and inhibited elastase activities in vitro. We also found that PDE inhibited UVB-induced cytotoxicity, MMP-1 production and expression of MMP-1, -3 and -9 mRNA in Hs68 cells. In addition, PDE decreased UVB-induced MMP-2 activity and MMP-2 mRNA expression. Moreover, PDE prevented the decrease of type I procollagen mediated by exposure to UVB irradiation, an effect that is linked to the upregulation and downregulation of Smad3 and Smad7, respectively. Another effect of UV irradiation is to stimulate activator protein 1 (AP-1) activity via overexpression of c-Jun/c-Fos, which, in turn, upregulates MMP-1, -3, and -9. In this study, we found that PDE suppressed UV-induced c-Jun and c-Fos mRNA expression. Taken together, these results demonstrate that PDE regulates UVB-induced expression of MMPs and type I procollagen synthesis by inhibiting AP-1 activity and restoring impaired Smad signaling, suggesting that PDE may be useful as an effective anti-photoaging agent.

Although p73 is a structural and functional homologue of the tumor-suppressor gene p53, it is not mutated in many human cancers as p53. Besides, p73 was shown to be activated by only a subset of signals that activate p53, such as y-irradiation and cisplatin, but not by other common genotoxic stress-inducing agents such as ultraviolet (UV) irradiation, although many of these signals are also capable of inducing p53-independent cell death. Using a p73-specific antibody, we confirmed that c-Abl is required for cisplatininduced p73 upregulation, and further demonstrate that the p73 protein is upregulated by UV irradiation and other stress stimuli including sorbitol, hydrogen peroxide, nocodazol, and taxol. These stress signals upregulate both p73 mRNA and increases the stability of p73, indicating that p73 is regulated transcriptionally and posttranslationally. Cells stably expressing the dominant-negative p73 inhibitor protein (p73DD) and p73-/- fibroblasts are more resistant than control cells to apoptosis induced by these stress signals, suggesting that p73 contributes to apoptosis induction. Together, the data demonstrate that several stress signals can signal to p73 in vivo, which raises the possibility of eradicating cancers with an unmutated p73 gene by activating them with stress-inducing agents or their mimetics.

Both non-degradable and biodegradable plastics can act as vectors of diverse organic pollutants. In this study, two types of biodegradable microplastics [poly (butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA)] and one type of non-degradable microplastics [polypropylene (PP)] were selected to investigate the impacts of ultraviolet (UV) irradiation for one month on microplastics surface modification and their adsorption behaviors for chlorpyrifos (CPF). The study revealed that PBAT held the largest adsorption capacity, and PLA held the fastest adsorption rate. The UV irradiation diminished the adsorption capacities on PLA and PP but enhanced the adsorption capacities on PBAT. The adsorption capacity normalized by specific surface area revealed that specific surface area was the dominant factor for affecting the adsorption capacities on PP and PLA after UV irradiation. These findings further clarify the interaction between CPF and microplastics, and provide a theoretical basis for assessing the ecological risk of microplastics in water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Large amounts of microplastics (MPs) enter the soil along with the amendment of sludge to soil. However, it is still unclear about the response of MPs occurrence and the adsorption behaviors of cadmium (Cd)on MPs to typical agricultural environmental scenarios. In present work, three kinds of MPs (polyethylene, polypropylene, and polystyrene) were chosen to investigate that response in three agricultural environmental scenarios with sludge-amended soil, including dry-wet alteration (7 d, five cycles), microbial addition (Bacillus subtilis, 0.05 g/g soil), and Ultraviolet (UV) irradiation (340 nm, 4 × 15 W, 4 d). The results showed that there was the highest adsorption capacity of Cd on MPs (36.21, 45.15, 12.43 μg/g for PE, PP, PS, respectively) after UV irradiation exceeding those from MPs triggered by other two scenarios). UV irradiation caused an increase in the abundance of Streptomyces, an expansion in specific surface area, a significant change in surface morphologies, an improvement in crystallinity or the formation of new crystals, and an enhancement in C-O and CO content, and then resulted in the incremental adsorption capacity of Cd on MPs. The findings are important of significance for controlling the environmental risks from sludge MPs via carrying heavy metals in the soil-plant systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Heavy metals are still the critical pollutants in industrial wastewater and there is an urgent need for efficient and environmentally friendly treatment technologies. Reduced graphene oxide (rGO) is widely used for preparations of nanofiltration (NF) membranes but suffers from poor hydrophilicity and electronegativity. In this work, a double-charged rGO/g-C 3 N 4 -P membrane was prepared for removal of heavy metals at low pressure. Graphitic carbon nitride (g-C 3 N 4 ) assisted reduction of GO membranes under ultraviolet (UV) irradiation, and the modification of functional groups with high polarity improved the hydrophilicity of membrane surface. The filtration performance for heavy metals of rGO/g-C 3 N 4 -P membrane was evaluated under low pressure (1-2 bar). The rejection rates of Cu 2+ , Cr 3+ , Mn 2+ , Cd 2+ , and Pb 2+ by membranes reduced by UV for 18 h (rGO/g-C 3 N 4 -18-P membrane) reached 94.72 %, 98.05 %, 82.32 %, 88.2 % and 77.15 %, respectively. In the experiment of mixed simulated wastewater, the rejection rates of NO 3 - and SO 4 2- both reached >95 %. Outstanding rejection rates were attributed to the interaction and the synergy effect of double-charged layers as well as steric effects. Meanwhile, the water flux of rGO/g-C 3 N 4 -18-P membrane was as high as 37.14-50.16 L m -2 h -1 bar -1 (1-2 bar). The high flux was due to the reduced degree of oxidation so that water molecules transported between GO nanochannels more smoothly and the transport path was shortened through the nanopores of g-C 3 N 4 . Obviously, flux and heavy metal rejection of rGO/g-C 3 N 4 -18-P membrane were simultaneously improved, breaking "trade-off" effect. Furthermore, rGO/g-C 3 N 4 -18-P membrane showed excellent antifouling ability and the potential for heavy metal wastewater filtration in comparison with other NF membranes reported in literature., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This study explored the risk of trichloronitromethane (TCNM) formation during chlorination of the nitrite-containing water after pre-chlorination and subsequent UV irradiation (i.e., the chlorine-UV process). The competitive reaction between amino acid (AA) and NO 2 - for chlorine produced organic chloramine and reduced the oxidation from NO 2 - to NO 3 - during UV photolysis of organic chloramines was confirmed. Among the process parameters, pre-chlorination time (from 5 min to 30 min) had no significant effect on TCNM formation; the highest TCNM formation occurred at pH 7 (from pH 6 to pH 8); prolonged UV irradiation time (from 5 min to 30 min) and increased chlorine to AA ratio (Cl -1 ) as compared to the absence of AA (0.42 μg L -1 ). The generation of HO • during UV photolysis of organic chloramines was confirmed. Among the process parameters, pre-chlorination time (from 5 min to 30 min) had no significant effect on TCNM formation; the highest TCNM formation occurred at pH 7 (from pH 6 to pH 8); prolonged UV irradiation time (from 5 min to 30 min) and increased chlorine to AA ratio (Cl 2 :AA) (from 1 to 3) decreased the TCNM formation. The hydroxylated, chlorinated and nitrosated products were detected. The quantum chemical calculation results indicated the attack of NO 2 • was more likely to occur at the meta and para positions of benzoic acid (BZA), because of the steric hindrance of the carboxylic group in BZA to the ortho position. Based on the results of the toxicity assessment, pre-chlorination with a higher chlorine dosage could be an effective method of controlling both TCNM formation and acute toxicity. Overall, the results of this study contributed to the understanding of the TCNM formation mechanism as well as optimizing the parameters of the chlorine-UV process to reduce the risk of TCNM formation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Ultra-high molecular weight polyethylene (UHMWPE) and CoCr alloy are popular tribo-pair in total knee replacement. Wear in the liner is a major failure reason for knee implant. Therefore, this work focuses on an approach for reducing the wear rate by irradiating the UHMWPE specimens using Ultraviolet (UV) radiation. The powder of UHMWPE was molded into a plate by microwave-assisted compression (MAC) molding. The UV radiations of intensity 0.025 J/cm 2 were irradiated on the MAC molded UHMWPE specimens. The wear rate was determined using a pin on the disc wear tribometer using the pre and post-irradiated UHMWPE specimens as a pin and CoCr alloy as the disc. The pre and post-irradiated UHMWPE sliding was done at the load of 40 N for 1500 m under dry conditions. The reduction in the wear rate recorded was 56% after UV irradiation. The surface morphology of the worn specimens was done using scanning electron microscopy (SEM) and the 3D surface mapping technique. The obtained results of wear rate were validated numerically by implementing the contact problem solution in Archard's wear law using user-subroutine on Python. The experimental and numerically obtained results were in good agreement. The biological response of pre and post-irradiated specimens was evaluated by hemolysis assay, cellular compatibility against peripheral blood mononuclear cells, platelet adhesion, and in vitro degradation under a simulated blood fluid environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Polyethylene (PE) is one of the most widely used plastics. However, the chemical inertness, inefficient recycling, and random landfilling of PE waste have caused serious pollution to the natural environment. In this study, a series of laccase-mediator systems (LMS) were constructed by combination of two laccases from Botrytis aclada (BaLac) and Bacillus subtilis (BsLac) with three synthetic mediators (ABTS, HBT, and TEMPO) to oxidize LDPE films (UVPE) pretreated with high-temperature UV irradiation. Scanning electron microscopy showed aging phenomena such as etching, fragmentation, and cracking on the surface of the UVPE films after LMS incubation. The FTIR results showed that LMS-UVPE added new oxygen-containing functional groups such as -OH, -CO, and CC. High-temperature gel chromatography confirmed that the average reduction in weight-average molecular weight (Mw) was approximately 40% for the BaLac experimental group. GC-MS analysis showed the presence of oxygen-containing products, such as aldehydes, ketones, and alcohols, in the reaction mixture. To verify the oxidation process UVPE degradation by LMS, we inferred three possible pathways by combined analysis of the oxidation products of LMS on UVPE and model substrates oleic acid and squalene., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Microplastic-derived dissolved organic matter (MP-DOM) is ubiquitous in water environment and exhibits photosensitivity. However, little is known about the effects of MP-DOM on the photodegradation of organic micropollutants in natural water. In this study, we investigated the effect of MP-DOM derived from two typical plastics, i.e., polystyrene (PS), and polyethylene (PE), on the photodegradation of a typical organic micropollutants sulfamethoxazole (SMX) in a simulative natural water system. MP-DOM exerted a significant inhibition on the SMX photodegradation, mainly attributed to the direct photolysis inhibition of SMX caused by the inner filter effect and the complexation effect. Despite the enhanced reactive oxygen species (ROS) generation with the increase of their steady-state concentration by 41.1 - 160.7 %, PS-DOM exhibited high oxidation resistance, causing an inhibition on the photodegradation of SMX probably through transferring electrons to the SMX intermediates. This study helps to deepen the understanding of microplastic photochemical behavior in natural water., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The ubiquitously present dissolved organic matter (DOM) greatly influence the efficiency of UV-based technologies due to its reactivity to UV irradiation. In this work, UV-induced changes within three hydrophobic DOM fractions isolated from different surface waters were investigated. Analysis on UV absorbance at 254 nm, electron donating capacity, fluorescence intensity and carbon content revealed small changes in DOM bulk properties associated with the UV-induced photochemical reactions. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was further used to explore the modification of the molecular distribution based on H/C and O/C ratios, m/z and DBE. The molecular-level investigation revealed that an average of 296 aromatic and lignin-like molecules were degraded, leading to the production of around 306 new molecules. The UV-reactive community were identified as CHO molecules with higher DBE (>10) and carbon number (>25) which could be readily transformed into smaller saturated molecules. Molecules containing nitrogen (N) or sulfur (S) atom, independent of aromaticity and molecular weight (m/z), were also highly UV susceptible and transformed into molecules with larger DBE and m/z. Possible reaction pathways responsible for the observations were discussed. The results indicated that UV-reactivity and subsequent transformation of DOM are remarkably correlated with its molecular composition and characteristics. Though the changes in bulk properties of DOM following UV irradiation were observed to be very small, the significant alteration in its molecular structures would have a profound impact on the UV-based treatment processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)