Occurrence characteristics, source analysis and ecological risk of PFASs in different cultivated soil at an urban scale in Yangtze River Basin

Per- and polyfluorinated substances (PFASs) contaminates the arable soil through multiple paths, and poses a threat to both farmland ecosystems and human health. In this study, the potential sources and distribution characteristics of 12 legacy PFASs in the soil and rivers for irrigation purposes were investigated in farmland systems, and the risks posed by PFASs to earthworm and aquatic organisms were also assessed. Based on field investigations in Yangtze River Basin, we found long-chain perfluoroalkyl carboxylic acids (PFCAs) were the major contaminants in arable soil and rivers for irrigation purposes, with PFOA (Perfluorooctanoic acid) being the most dominant monomer. Concentration levels of PFASs in arable soil were strongly related to land use types, the average concentration of PFASs (341.18 ± 600.19 ng/g) in the paddy fields was 100-fold higher than that of dry fields (3.79 ± 4.11 ng/g). Source apportionment revealed that PFASs detected in paddy fields were mainly associated with industrial effluents, domestic sewage, and irrigation water. In rivers for irrigation purposes, higher PFASs contamination were primarily distributed in industrial areas, such as plastic processing, paper, textile and electronics factories. The PFASs in the irrigation river water posed a low-medium risk to daphnia and fish, while the PFASs (PFOA and perfluorododecanoic acid (PFDoDA)) in soil posed a medium-high risk to earthworms. These results provided insights that sewage irrigation caused serious pollution of PFASs in the agricultural environment, should be paid more attention

Fabrication of Ca-doped TiO2 for enhanced methylene blue degradation under UV-Vis irradiation

Research continues to improve the dye degradation performance of TiO2 nanoparticles (NPs) through doping, tailoring, or modifying the lattice structure. A series of Ca–TiO2 (Ca ions 0.5–2.0 wt%) photocatalysts prepared by wet impregnation method were studied for methylene blue (MB) degradation under UV-Vis irradiation, using different factors, including contact time, pH, initial dye concentration, and dosages. The photocatalyst samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Characterization results revealed the successful doping of Ca ion on the TiO2 surface, and Ti, O, and Ca were identified by EDX analysis as being present in the Ca-doped TiO2 sample. Calcium improved titania's charge separation capability, favoring the formation of more hydroxyl radicals during irradiation. Another important effect of Ca is the lowered bandgap energy of TiO2, which enhances the light absorption capacity into the visible regions. The photocatalytic performance varied with calcium ions content in the prepared catalysts, and a moderate amount showed the best activity. 1 wt% Ca–TiO2 exhibited a maximum MB degradation of 79.65 % with TOC removal of 52.36 % and followed the pseudo-first-order reactions kinetics with a rate constant of 0.0087 min−1. Notably, both the degradation performance and rate constant of 1 wt% Ca-TiO2 catalysts were much superior to pure TiO2 under the same reaction conditions. This finding suggests that Ca-TiO2 NPs could be a highly effective photocatalyst for the ecologically benign degradation of color compounds in textile wastewater

Experimental investigation on the failure characteristic and synergistic load-bearing mechanism of multi-layer linings for deep soft rock tunnels

Multi-layer linings have been widely used in deep rheological soft rock tunnels for the excellent performance in preventing large-deformation hazards. Previous studies have focused on the bearing capability of multi-layer lining, however, its failure characteristics and synergistic load-bearing mechanisms under high geo-stress are still unclear. To fill the gap, three-dimensional geomechanical model tests were conducted and synergistic mechanisms were analysed in this study. The model test was divided into normal loading, excavating, and overloading stages. The surrounding rock deformation was monitored by using an improved high-precise extensometer measurement system. Results show that the largest radial deformation appears on the sidewall, followed by the floor and vault during the excavating stage. The relative convergence deformation of sidewalls springing reaches 1.32 mm. The failure characteristics of the multi-layer linings during the overloading stage undergo an evolution of stability, crack initiation, local failure, and collapse, with a safety factor of 1.0–1.6, 1.6–2.0, and 2.0–2.2, respectively. The synergistic load-bearing mechanism analysis results suggest that the early stiffness and late yielding deformation capacity of large deformation support measures play important roles in stability maintenance both in the construction and operation of deep soft rock tunnels. Therefore, the combination of yielding support or a compressible layer with reinforced support is recommended to mitigate the effect of the high geo-stress

Stability, deactivation and regeneration study of a newly developed HZSM-5 and Ni-doped HZSM-5 zeolite catalysts for ethanol-to-hydrocarbon conversion

This work investigates the stability and regeneration of HZSM-5 and Ni/HZSM-5 catalysts in the ethanol-to-hydrocarbon conversion. The catalysts were characterised using different techniques and evaluated at 623 K and 7 h−1 for 96 h TOS with two regeneration cycles. HZSM-5 showed high stability with 100% ethanol conversion, while Ni/HZSM-5 catalysts maintained 100% stability for 48 h before dropping. Regenerated catalysts were comparable to the originals in terms of product distribution, stability, and performance. HZSM-5 preferred BTX, while Ni-doped catalysts favoured C5-C8, C9-C12, and C12+ synthesis. The regeneration process restored catalytic activity, especially for the Ni-doped catalysts, extending their life and reducing replacement costs

Effect of hydro-alcoholic extract of Nigella sativa on cisplatin-induced memory impairment and brain oxidative stress status in male rats

Objective: Studies have shown the complications of chemotherapy on learning and memory. Empirical evidence suggests that Nigella sativa (NS) has neuroprotective activities. Therefore, the aim of our study was to investigate the effects of NS on cisplatin-induced memory impairment.Materials and Methods: This study was conducted on 40 male rats grouped as: control (saline: 2 ml/kg, intraperitoneally (IP), once weekly/2 weeks), cisplatin (Cis, 2 mg/kg, IP, once weekly/2 weeks), NS (200 mg/kg, IP, once weekly/2 weeks), Cis +NS 200 (2 mg/kg Cis + 200 mg/kg NS, IP, once weekly/2 weeks), and Cis +NS 400 (2 mg/kg Cis + 400 mg/kg NS, IP, once weekly/2 weeks). Morris water maze (MWM) test was used to assess spatial learning and memory. In addition, superoxide dismutase (SOD) activity, and thiol and malondialdehyde (MDA) levels were evaluated in the brain.Results: Cis significantly enhanced the traveled distance and time spent in the target quadrant in the MWM test. Additionally, MDA levels increased in the Cis group, while thiol and SOD decreased in this group. As a result of treatment with NS, behavioral results were reversed in the groups receiving NS compared to the Cis group. Also, NS reduced MDA level but improved SOD and thiol levels in brain tissue samples.Conclusion: NS could improve memory impairment and oxidative stress in animals receiving Cis. Therefore, NS could be used as a potential food supplement to prevent neurotoxicity in patients undergoing chemotherapy

Robotont 3–an accessible 3D-printable ROS-supported open-source mobile robot for education and research

Educational robots offer a platform for training aspiring engineers and building trust in technology that is envisioned to shape how we work and live. In education, accessibility and modularity are significant in the choice of such a technological platform. In order to foster continuous development of the robots as well as to improve student engagement in the design and fabrication process, safe production methods with low accessibility barriers should be chosen. In this paper, we present Robotont 3, an open-source mobile robot that leverages Fused Deposition Modeling (FDM) 3D-printing for manufacturing the chassis and a single dedicated system board that can be ordered from online printed circuit board (PCB) assembly services. To promote accessibility, the project follows open hardware practices, such as design transparency, permissive licensing, accessibility in manufacturing methods, and comprehensive documentation. Semantic Versioning was incorporated to improve maintainability in development. Compared to the earlier versions, Robotont 3 maintains all the technical capabilities, while featuring an improved hardware setup to enhance the ease of fabrication and assembly, and modularity. The improvements increase the accessibility, scalability and flexibility of the platform in an educational setting

Enhanced detection of freeze‒thaw induced landslides in Zhidoi county (Tibetan Plateau, China) with Google Earth Engine and image fusion

Freeze‒thaw induced landslides (FTILs) in grasslands on the Tibetan Plateau are a geological disaster leading to soil erosion. These landslides reduce biodiversity and intensify landscape fragmentation, which in turn are strengthen by the persistent climate change and increased anthropogenic activities. However, conventional techniques for mapping FTILs on a regional scale are impractical due to their labor-intensive, costly, and time-consuming nature. This study focuses on improving FTILs detection by implementing image fusion-based Google Earth Engine (GEE) and a random forest algorithm. Integration of multiple data sources, including texture features, index features, spectral features, slope, and vertical‒vertical polarization data, allow automatic detection of the spatial distribution characteristics of FTILs in Zhidoi county, which is located within the Qinghai‒Tibet Engineering Corridor (QTEC). We employed statistical techniques to elucidate the mechanisms influencing FTILs occurrence. The enhanced method identifies two schemes that achieve high accuracy using a smaller training sample (scheme A: 94.1%; scheme D: 94.5%) compared to other methods (scheme B: 50.0%; scheme C: 95.8%). This methodology is effective in generating accurate results using only ∼10% of the training sample size necessitated by other methods. The spatial distribution patterns of FTILs generated for 2021 are similar to those obtained using various other training sample sources, with a primary concentration observed along the central region traversed by the QTEC. The results highlight the slope as the most crucial feature in the fusion images, accounting for 93% of FTILs occurring on gentle slopes ranging from 0° to 14°. This study provides a theoretical framework and technological reference for the identification, monitoring, prevention and control of FTILs in grasslands. Such developments hold the potential to benefit the management of grassland ecosystem, reduce economic losses, and promote grassland sustainability

Oil‐Infused Polymer Fiber Membranes as Porous Patches for Long‐Term Skin Hydration and Moisturization

Abstract Skin allergies and diseases, including atopic dermatitis (AD), affect millions worldwide. Current treatments for AD are often expensive, leading to a need for cost‐effective solutions. Here, using fiber‐based patches to maintain and increase skin hydration is explored, which helps treat eczema and AD. Nanofiber membranes are manufactured via electrospinning of eight different polymers: nylon 6 (PA6), polyimide (PI), poly(3‐hydroxybuty‐rate‐co‐3‐hydroxyvalerate (PHBV), poly(l‐lactide) (PLLA), polycaprolactone (PCL), and polystyrene (PS), and two molecular weights poly(vinyl butyral‐co‐vinyl alcohol‐co‐vinyl acetate) (PVB). Further, their morphology is examined through scanning electron microscopy (SEM), fibers, and pores diameter, wettability, and membrane thickness. Additionally, water vapor transmission rates (WVTR) are measured, and notably, skin hydration tests are conducted before and after using evening primrose oil‐infused patches. The comparison and findings highlight the flexibility of electrospun patches, demonstrating their potential in maintaining skin hydration for 6 h and enhancing skin moisture, which are necessary in AD treatment. These insights, which focus on selecting the most effective performance patches, help improve skin moisture, leading to tailored treatments for AD, which can significantly impact the efforts to reduce healthcare costs and simplify skincare steps