Search Results (362)

Invasive species are a recurring global problem, and the water hyacinth (Pontederia crassipes) is a well-known example. Various strategies have been explored to manage its spread, including its use as an agricultural amendment. However, when P. crassipes biomass is incorporated into soil and undergoes degradation, it may increase soil conductivity and promote metal leaching, potentially affecting soil biota, particularly microbiota. Saprophytic fungi play a key role in the decomposition and renewal of organic matter, and their resilience to stressors is crucial for maintaining soil function. Thus, the aim of this study was to evaluate the effects of P. crassipes biomass extracts on the saprophytic fungus Trametes versicolor by evaluating fungal growth and metabolic changes [including sugar content, phosphatase enzymatic activity, and reactive oxygen species (ROS) production]. The fungus was exposed for 8 days to a dilution series of extracts (100%—undiluted, to 3.13%) prepared from P. crassipes biomass collected at five locations in Portuguese wetlands. Two sites were in the south, within a Mediterranean climate (Sorraia and Estação Experimental António Teixeira), and three were in the north, within an Atlantic climate (São João de Loure, Pateira de Fermentelos, and Vila Valente), representing both agricultural-runoff–impacted areas and recreational zones. Extracts were used to simulate a worst-case scenario. All extracts have shown high conductivity (≥15.4 mS/cm), and several elements have shown a high soluble fraction (e.g., K, P, As, or Ba), indicating substantial leaching from the biomass to the extracts. Despite this, T. versicolor growth rates were generally not inhibited, except for exposure to the São João de Loure extract, where an EC₅₀ of 45.3% (extract dilution) was determined and a significant sugar content decrease was observed at extract concentrations ≥25%. Possibly due to the high phosphorous leachability, both acid and alkaline phosphatase activities increased significantly at the highest percentages tested (50% and 100%). Furthermore, ROS levels increased with increasing extract concentrations, yet marginal changes were observed in growth rates, suggesting that T. versicolor may efficiently regulate its intracellular redox balance under stress conditions. Overall, these findings indicate that the degradation of P. crassipes biomass in soils, while altering chemical properties and releasing soluble elements, may not impair and could even boost microbiota, namely saprophytic fungi. This resilience highlights the potential ecological benefit of saprophytic fungi in accelerating the decomposition of invasive plant residues and contribution to soil nutrient cycling and ecosystem recovery. Full article

Agricultural inputs based on microalgae have been successfully tested at different stages of the crop cycle, from sowing to harvest, to enhance crop performance. In this study, biomass from Nannochloropsis gaditana and Thalassiosira sp. was obtained to evaluate its effect on wheat seed germination under two temperature conditions. Microalgal biomass was produced under controlled conditions (neutral pH, air flow of 1 L·min⁻¹, and a dilution rate of 0.2 day⁻¹). The biomass was characterized for its lipid, carbohydrate, protein, and ash content. Subsequently, its effect on germination, as well as on glucose and amylose content in wheat seedlings, was assessed. Four biomass concentrations were tested (0.0 [distilled water], 0.5, 1.0, and 1.5 g·L⁻¹) at two incubation temperatures (25 and 35 °C). Results showed that Thalassiosira sp. lightly promoted the germination rate more than N. gaditana. Germination parameters were negatively affected by high temperature, but treatments with Thalassiosira sp. alleviated this effect, showing values comparable to those obtained at the optimal temperature. Vigor parameters were improved compared with the control in both temperatures. Glucose and amylose contents exhibited irregular but consistent patterns. However, at a temperature of 35 °C, a slight conversion of starch to glucose could be observed. Overall, microalgal biomass did not significantly improve germination or its time variables, but it could exert a protective effect against high-temperature stress, particularly in the case of Thalassiosira sp. Full article

At present, phosphogypsum, as an industrial by-product, is a solid waste in phosphoric acid production, and its accumulation has caused serious environmental pollution. Furthermore, due to the insufficient insulation properties of traditional wall materials, the issue of a rising proportion of building energy consumption in total social energy consumption has become increasingly pressing. The study investigated vitrified beads as a light aggregate and phosphogypsum, mineral powder, and quicklime as an inorganic composite cementitious system to prepare the phosphogypsum-based lightweight thermal insulation material. The effect mechanism of the initial material ratio on the mechanical properties and micro-morphology of insulation materials was studied by macroscale mechanical property testing, X-ray diffraction, and scanning electron microscopy. Meanwhile, in order to meet the performance indexes specified in relevant standards, insulation materials were modified by adding sulfate aluminate cement, basalt fibers, and a waterproof agent to improve the strength, toughness, and water resistance. Based on the single-factor experimental design, the optimal dosage of various admixtures was obtained. The results indicated that the optimal properties of the sample were achieved when the binder–bead ratio was 1:4, the water–binder ratio was 1.6, the dosage of hydroxypropyl methylcellulose was 0.1%, and the solid content of waterborne acrylic emulsion was 24%. The optimal dosages of cement and fibers were 8% and 0.9%, respectively. The cement hydration products and gypsum crystals lapped through each other, filling the pores in the matrix and increasing the strength of the sample. In addition, the fibers could form a disordered network structure inside the matrix, disperse external force, weaken the stress concentration at the tip of internal cracks, and significantly improve the toughness of the modified sample. By incorporating 2.0% paraffin emulsion in the mortar and spraying 5 dilutions of sodium methyl silicate on the external surface, dense protective layers were formed both inside and outside the modified sample. The water absorption rate reduced from 30.27% to 23.30%, and the water resistance was increased to satisfy the specified requirement for the insulation material. Full article

Unsaturated polyester resins (UPRs) were synthesized from camphoric acid and diluted with styrene, partially replaced (up to 30%) by trimethylolpropane triacrylate (TMPTA). Rheological tests showed increased but sustainable viscosity due to TMPTA’s higher polarity. These UPRs served as matrices for composites reinforced with non-woven bamboo and flax mats from recycled waste. Mechanical testing revealed that C_f-UPR/TMPTA30 exhibited the highest tensile strength (25.2 MPa) and modulus (0.96 GPa), compared to 18.7 MPa and 0.74 GPa for the styrene-based resin, respectively, attributed to greater cross-link density. Bamboo composites showed lower tensile properties (13.6 MPa) due to random fiber orientation and porosity, while flax-reinforced systems, especially C_f-UPR/TMPTA30–FLAX, reached 42.7 MPa tensile and 95.5 MPa flexural strength, indicating synergy between TMPTA-modified resin and flax fibers. Dynamic-mechanical analysis confirmed stable thermo-mechanical behavior, and water uptake tests showed reduced absorption (by ~10%), suggesting improved fiber/matrix adhesion. SEM images revealed brittle fracture and fiber pull-out in styrene systems, but fiber breakage and ductile textures in TMPTA-based ones, proving better stress transfer. Thermal analysis indicated slightly earlier degradation onset for TMPTA-modified resins but higher char yield in fiber composites. Overall, TMPTA substitution and flax reinforcement enhance the mechanical, interfacial, and thermal properties of bio-based UPRs, supporting sustainable high-performance composites. Full article

Although purple non-sulfur bacteria (PNSB) have been studied as good biofertilizers, their direct effects on maize seed vigor remain unclear. Additionally, the seedling stage is a vital factor for the later growth of maize. This study was conducted to evaluate the effectiveness of potassium-solubilizing PNSB (K-PNSB) in enhancing the vigor of hybrid maize seeds. A completely randomized design was employed, incorporating single strains, Luteovulum sphaeroides M-Sl-09, Rhodopseudomonas thermotolerans M-So-11, and Rhodopseudomonas palustris M-So-14, as well as a mixture of all three strains. Each was tested at bacterial suspension dilution ratios with sterile distilled water of 1:2000; 1:2250; 1:2500; 1:2750; and 1:3000 (v/v), with three replications per treatment. Each replicate consisted of a Petri dish containing 10 hybrid maize seeds of each hybrid of LVN 10, C.P. 511, and NK7328 Gt/BT, and was incubated for five days. The results showed that K-PNSB significantly enhanced root and shoot development compared to the control (p < 0.05). The 1:2500 dilution of the individual strains and the mixture notably improved germination rate, root length, shoot length, and seedling vigor index compared to the control. At the 1:2500 dilution, the improved vigor index increased by 73.5% for L. sphaeroides, 48.7% for R. thermotolerans, 47.4% for R. palustris, and 78.5% for the mixed inoculum in the LVN 10 hybrid. Similar trends were observed for C.P. 511 and NK7328 hybrids, confirming strain- and hybrid-specific responses. The findings highlight that K-PNSB can serve as effective bio-priming agents to enhance maize seed vigor through mechanisms related to potassium solubilization and phytohormone production. Field-scale validation is recommended to assess their long-term agronomic potential. Full article

The disposal of coal mine solid waste has always been a challenge in the coal mining production process, and the research and development of low-cost and high-performance filling materials is a prerequisite for achieving large-scale disposal of coal mine solid waste. The effects of water–cement ratio, foaming agent dilution ratio, foam agent content, foam stabilizer content, and gypsum content on the mechanical properties, transportation characteristics, and microstructure of cement foam filling materials were studied by laboratory test methods. The optimal ratio of cement foam filling material for comprehensive performance was determined. On this basis, the mechanism of influence of fly ash content, gangue content, and gangue particle size on the mechanics, transportation characteristics, and microstructure of foam filling materials was further studied. The experimental results show that at fly ash contents below 30%, gangue content is less than 30%. The particle size of gangue is less than 0.6 mm, and the expansion ratio of coal mine solid waste foam filling material is about three times, which has good mechanical properties and transportation performance. The on-site test results show that the control effect of the surrounding rock in the goaf is good, achieving safe and efficient mining of the working face. Full article

Wastewater treatment plants (WWTPs) play a key role in the protection of the environment and public health by reducing the levels of pollutants released into the water. Here, we evaluate the quality of water obtained from two key points of the treatment process of a municipal WWTP (León, Spain) using zebrafish (Danio rerio) embryos and larvae as sentinels. Three experimental groups were established: (1) “Control” (CTRL) maintained in embryo medium, (2) “Influent” (I) exposed to influent water before the secondary (biological) treatment (concentrations: I-100% and I-75%), and (3) “Effluent” (E) exposed to effluent water from the secondary treatment (concentrations: E-100% and E-75%). Our results confirmed that survival was subtly affected in I-100% and E-100%, as well as the hatching rate in the effluent. Larvae exposed to both experimental conditions also presented a higher rate of malformations, affecting biometry and showing reduced embryo motility, with the exception of E-75%. The I-100% condition also caused reduced heartbeat, reduced fin regeneration, and a higher number of delocalized primordial germ cells. I-100%-exposed larvae showed dysregulation of four genes (foxm1l, cenpf3b, hoxc6a, and ddit3) out of the 19 studied. Effluent dilution mitigated the observed effects, and the model proved to be an effective additional test for wastewater treatment plants. Full article

In this paper, different physiochemical and biological indicators were tested to determine and compare the water quality of the Zaalklapspruit ecologically engineered wetland before and after a veldfire. Five sampling sites and a reference site 2.2 km upstream of an acid mine drainage (AMD)-decanting coal mine were selected and sampled before and after the veldfire. The “black box” method was also employed to determine the percentage change in the selected in- and outflow variables before and after the veldfire. After the veldfire, Al was reduced by 97.43%. The same trend was observed for Fe, which decreased by 99.65% at the outflow, and Mn and sulphate levels decreased by 98.41% and 68.16%. Possible pathways of the reduction in acid mine drainage impacts on the wetland were identified after the veldfire, including the increase in waterflows during the wet season causing a dilution factor, and phycoremediation by macroalgae drifting mats that accumulate metals and ash slurry from the burned-out macrophyte plant material that may have increased the wetland’s alkalinity. A comprehensive framework for the digital twinning and monitoring of the effects of natural disasters on wetlands is also presented. Full article

This study explored the feasibility of noninvasive blood glucose (BG) estimation using near-infrared (NIR) spectroscopy with dog blood samples. A sensor module employing three representative wavelengths (770 nm, 850 nm, and 970 nm) was tested on an artificial blood vessel (ABV) and a thin pig skin (TPS) model. BG concentrations were adjusted through dilution and enrichment with injection-grade water and glucose solution, and reference values were obtained from three commercial invasive glucometers. Correlations between NIR spectral responses and glucose variations were quantitatively evaluated using linear, multiple, partial least squares (PLS), logistic regression, regularized linear models, and multilayer perceptron (MLP) analysis. The results revealed distinct negative correlations at 850 nm and 970 nm, identifying these wavelengths as promising candidates for noninvasive glucose sensing. Furthermore, an NIR–glucose database generated from actual dog blood was established, which may serve as a valuable resource for the development of future noninvasive glucose monitoring systems. Full article

Cenchrus setaceus is an alien invasive species with significant ecological impact on both natural ecosystems and agricultural areas across the Canary Islands. In this study, we evaluated the allelopathic effects of foliar lixiviates from two endemic species, Artemisia thuscula and Plocama pendula, on Cenchrus setaceus and a group of crop species to assess (i) germination inhibition of the invasive species and (ii) selectivity towards non-target crops. A preliminary trial tested undiluted and diluted forms (1%, 10%) of concentrated lixiviates prepared at a 1:3 (w:v) leaf-to-water ratio, using C. setaceus and Lactuca sativa under growth chamber conditions. In the validation trial, lixiviates prepared at a 1:6 (w:v) ratio were applied directly to C. setaceus and seven crops (Zea mays, Allium cepa, Hordeum vulgare, L. sativa, Solanum lycopersicum, Brassica oleracea, and Raphanus sativus) under both growth chamber and greenhouse conditions. Germination indices were calculated across assays, and plumule and radicle lengths were measured in growth chamber assays. In both trials, C. setaceus germination was inhibited by up to 60% by both ratios of lixiviates (Dunn p < 0.05), with reduced speed and seedling growth (plumule: −37.5%; radicle: −85%). Crop sensitivity varied: A. cepa and H. vulgare showed no significant inhibition; B. oleracea and R. sativus were affected by P. pendula (germination reduced 2.5–2.7×); and Z. mays, L. sativa, and S. lycopersicum exhibited delayed germination and reduced seedling growth under both treatments. These results support the selective use of native plant lixiviates for integrated management of Cenchrus setaceus in sensitive agroecosystems. Full article

In this study, nanostructured ferberites (FeWO₄) were synthesized via hydrothermal routes in an acidic medium. It was then investigated as an efficient photocatalyst for degrading organic dye molecules, with methylene blue (MB) as a model pollutant. The formation mechanism of ferberite revealed that the physical form of the precursor, FeSO₄·7H₂O, acts as a decisive factor in morphological evolution. Depending on whether it is in a solid or dilute solution form, two distinct nanostructures are produced: nanoplatelets and self-organized microspheres. Both structures are composed of stoichiometric FeWO₄ (Fe: 49%, W: 51%) in a single monoclinic phase (space group P2/c:1) with high purity and crystallinity. The p-type semiconductor behavior was confirmed using Mott–Schottky model and the optical analysis, resulting in small band gap energies (≈1.7 eV) favoring visible absorption light. Photocatalytic tests under simulated solar irradiation revealed rapid and efficient degradation in less than 10 min under near-industrial conditions (pH 5). This was achieved using only a ferberite catalyst and a low concentration of H₂O₂ (4 mM) without additives, dopants, or artificial light sources. Advanced studies based on photocurrent measurements, trapping and stability tests were carried out to identify the main reactive species involved in the photocatalytic process and better understanding of photodegradation mechanisms. These results demonstrate the potential of nanostructured FeWO₄ as a sustainable and effective photocatalyst for water purification applications. Full article

The widespread use of antimicrobial drugs (AMDs) in livestock production contributes to antimicrobial resistance (AMR), a global One Health concern affecting humans, animals, and the environment. This study analyzed AMD residues and the AMR profiles in Escherichia coli and Enterococcus spp./Streptococcus spp. (ES) isolated from lagoon water samples collected from nine California dairies. Antimicrobial susceptibility testing was performed using the microbroth dilution method, and enzyme-linked immunosorbent assay (ELISA) kits were used to detect AMD residues in lagoon water. Overall, residues of florfenicol and tilmicosin were detected in more than 90% of the samples, while tetracycline was detected in 74.2 ± 4.6% of the samples. In contrast, penicillin and sulfamethazone residues were low, observed in only 3.4 ± 1.9% and 32.3 ± 5.0% of samples, respectively. The very low prevalence of penicillin was likely due to limited use in dairy cattle, given its prolonged withdrawal period. Prevalence estimates for AMR in the lagoon samples showed 100% resistance of E. coli to tiamulin, tilmicosin or tylosin and high prevalence against florfenicol (96.0% ± 2.0) or gamithromycin (92.0% ± 1.9). However, low AMR estimates (less than 10%) were observed against other AMDs tested. Similarly, the prevalence estimates for AMR of ES isolates in the studied lagoon were high against florfenicol (95.1% ± 2.0), tildipirosin (97.6% ± 1.7), or tilmicosin (98.8% ± 1.2), but low against ampicillin (4.9% ± 1.9) and penicillin (8.5% ± 2.4). Despite numerical differences in AMR prevalence by season, region, and sampling point, these variations were not statistically significant. Logistic regression models were applied to explore associations between AMD residues and AMR phenotypes where appropriate. Tilmicosin residues were significantly associated with reduced resistance to danofloxacin, enrofloxacin, and tildipirosin in E. coli isolates, while sulfamethoxazole residues were linked to increased tetracycline resistance in Enterococcus spp. The presence of florfenicol residues, potentially originating from treated calves and heifers, helps explain the high prevalence of resistance to this drug in both bacterial species. However, not all AMD residues were associated with AMR, underscoring the complex ecological and genetic factors involved in the development and maintenance of resistance in dairy environments. These findings underscore the importance of integrating AMR surveillance and prudent AMD use practices across all segments of dairy production systems. Full article

Growing consumer demand for healthier meat products with clean-label ingredients has increased interest in plant-based fortification strategies. The present study evaluated the effects of a multicomponent cereal supplement comprising rice (35%), buckwheat (20%), oats (20%), and corn (25%) on the physicochemical, functional, oxidative, hydrolytic, and sensory properties of meat patties. Four formulations were prepared with 0% (control), 5%, 10%, and 15% supplement inclusion. At higher inclusion levels of the cereal supplement, the patties showed reduced moisture, protein, and fat contents, while ash and carbohydrate levels increased. Conversely, ash content increased from 1.38% to 2.82%, and carbohydrates rose to 8.99%. pH remained stable (5.92–6.04), whereas aw decreased significantly at 10% (0.921) and 15% (0.889) inclusion (p < 0.05). Functional tests showed dose-dependent improvements in water-binding capacity, which increased from 65.98% in the control to 71.58% at 10% supplement, and in fat retention, which rose from 38.3% to 54.14% under the same conditions, with optimal performance observed at 10% inclusion. TBARS values in 10% and 15% formulations were 13–20% lower than control throughout storage (p < 0.05). The increase in acid number was significantly slower in supplemented patties, indicating that the cereal blend effectively inhibited lipid hydrolysis during storage. Sensory evaluation revealed maximal acceptability at 10% inclusion, with declines at 15% due to grainy texture and flavor dilution. These findings establish 10% multicomponent cereal supplementation as a promising strategy to enhance yield, shelf-life stability, and consumer appeal of meat patties without compromising processing parameters. Full article

Purity analysis of parent gases used to produce reference gas mixtures is fundamental to assure the metrological traceability of the certified gas composition, and the use of purity data in the calculation of the mixture composition should be performed in accordance with the requirements of international standards. Purity analysis can be difficult to realize since limited measurement standards are available for the determination of trace levels of gaseous compounds. The first step of purity analysis is the definition of the impurities considered critical or significant to the final composition of a mixture. In this work, we present the activity carried out for the identification and quantification of impurities of carbon dioxide and water in some ultrapure gases used for the preparation of primary certified reference gas mixtures of carbon dioxide at atmospheric amount fraction (400–800 µmol·mol⁻¹), by means of different spectroscopic techniques (Fourier Transform IR, Non-Dispersive IR and Cavity Ring-Down). Dynamic dilution was used for the generation of reference mixtures for the calibration of the analyzers by using calibrated Mass Flow Controllers. The certified reference gas mixtures produced with the tested pure gases will also be applied to characterization studies and calibration protocols for gas sensors used both for outdoor and indoor monitoring. Full article

High-permeability emulsified asphalt has emerged as a promising prime coat for enhancing interlayer bonding in semi-rigid pavement structures. However, its widespread adoption remains limited by insufficient permeability and inconsistent mechanical properties. This study systematically investigated the effects of emulsifier ionic type (cationic or anionic), kerosene dosage (0–20%), and diluted asphalt content (corresponding to oil-water ratios of 5:5 and 4:6) on the comprehensive performance of high-permeability emulsified asphalt. Fundamental physical tests (sieve residue, evaporation residue, penetration, softening point, ductility), permeability evaluation, rotational viscosity measurements, and adhesion performance tests were conducted. Grey relational analysis (GRA) was employed to quantify the influence of each factor and their interactions on key performance metrics. The results reveal that anionic emulsifiers significantly improved low-temperature ductility and permeability. A low kerosene dosage (<10%) enhanced permeability and viscosity but compromised thermal stability at higher levels. Reducing the diluted asphalt content partially offset these adverse effects. GRA identified kerosene dosage as the dominant factor influencing permeability, softening point, and adhesion performance while emulsifier ionic type primarily affected ductility, and oil-water ratio strongly governed emulsification quality and viscosity. These findings provide quantitative insights for optimizing the composition of high-permeability emulsified asphalt and serve as a theoretical foundation for its engineering application in durable prime coats. Full article