Search Results (519)

Olive mill wastewater (OMWW) is a highly polluting agro-industrial effluent characterized by elevated organic load, low pH, and high concentrations of phenolic compounds responsible for its phytotoxicity and dark coloration. In this study, 41 non-conventional yeast strains belonging to the University of Basilicata Yeast Collection (UBYC), were tested for both the oleaginous potential traits and OMWW detoxification capacity in comparison to two commercial oleaginous controls, Yarrowia lipolytica ATCC 46483 and Lipomyces tetrasporus Li-0407. Primary screening in synthetic medium under nitrogen-limited conditions revealed widespread intracellular lipid accumulation. Quantitative analysis showed lipid contents above 20% (w/w) in some strains, with Candida tropicalis AII122 (33.3%) and Pichia manshurica ML-3 (29.4%) exhibiting the highest values in synthetic medium. The cultivation of eight selected strains in synthetic medium supplemented with 15% (v/v) of OMWW reduced intracellular lipid accumulation, with the highest value of 6.48% for the 2R1 strain. Levels of phenol reduction and color removal were highly different among all the analyzed strains, and C. tropicalis AII122 achieved the highest phenolic reduction and decolorization ability. These findings demonstrate that indigenous non-conventional yeasts represent a source of natural biodiversity, supporting sustainable waste valorization strategies based on the use of selected microorganisms within a circular bioeconomy framework. Full article

The use of nanoparticles (NPs) synthesized from plant extracts is an alternative to conventional pesticides for the control of agricultural pests. This study aimed to optimize the conditions of synthesis of silver–zinc nanoparticles (Ag-ZnNPs) using extracts of Ocimum basilicum L. and Crotalaria longirostrata Hook. & Arn. and to evaluate their phytotoxic impact on maize seedlings. The Ag-ZnNPs (Ag-Zn nanoparticles) were synthesized by redox reaction between metal ions and reducing metabolites present in the extracts. A response surface methodology (RSM) with three factors (extract concentration, heating time and pressure) was applied to determine the optimal synthesis conditions. The phytotoxicity of nanoparticles (NPs) on maize seedlings was subsequently evaluated on root growth, oxidative stress enzymes (CAT, POD, and APX), and physiology of seedlings. Nanoparticles synthesized from C. longirostrata extract demonstrated superior properties, with an optimization of synthesis (R² = 95.3%) where the extract concentration (1:4 v/v; p < 0.01) was the critical factor influencing the reduction of metallic ions to nanoparticles. These NPs exhibited superior stability, smaller size (<100 nm), and zeta potential greater than 30 mV compared with O. basilicum extracts. Their NPs exhibited poorer optimization of synthesis (R² = 43.8%) without the effect of any of the variables evaluated. Essentially, C. longirostrata NPs showed no phytotoxic effects on maize seedlings’ physiological parameters and enhanced root growth (117.2 mm) without negatively affecting photosynthesis (PSII 70-81 FvFm). Ag-ZnNPs synthesized with C. longirostrata exhibited optimal stability and size, along with no observed possible phytotoxicity effects, unlike O. basilicum NPs, which cause stress on maize seedlings. Therefore, Crotalaria longirostrata NPs could represent a promising material for agricultural pest control, with no apparent adverse effect on maize crops. Full article

This study presents a statistically optimized protocol for the green synthesis of gold nanoparticles (Au NPs) using aqueous Kalanchoe pinnata leaf extract (AKPLE). An integrated experimental strategy, transitioning from preliminary one-factor-at-a-time (OFAT) screening to a five-factor Box–Behnken Design, was employed to model and simultaneously optimize two critical optical responses derived from surface plasmon resonance: the peak position (λ_max) and its absorbance intensity. Highly predictive quadratic models (R² > 0.97) revealed that synthesis outcomes are governed by significant nonlinear curvature, with minimal interaction effects. Multi-response optimization via a desirability function identified a harmonized set of conditions (HAuCl₄: 0.44 mM, AKPLE: 3.50% v/v, temperature: 80.6 °C, pH: 7.2, time: 66.7 min) predicted to minimize λ_max at 540 nm while maximizing absorbance to 0.61. Synthesis under these optimized conditions successfully produced spherical, crystalline Au NPs, as confirmed by characterization (average TEM size: 26.3 ± 4.1 nm; zeta potential: –30.45 mV). This work demonstrates that a hybrid OFAT-RSM approach is superior for the precise, multivariate optimization of plant-mediated Au NP synthesis, providing a validated and scalable framework to balance nanoparticle size and plasmonic intensity—an outcome unattainable through conventional OFAT methods. Full article

The aim of the current study was to select and test the appropriate model and input parameters for remote sensing retrieval of surface soil moisture (SSM) in the case of bare Chernozems on flat and sloping terrains in northern Bulgaria under different tillage systems. Normalized synthetic aperture radar (SAR) measurements from Sentinel-1 C-band dual-pol products (Gamma-Nought in VV, ratio) were utilized in two ways to delineate SSM from environmental factors that bias determination. The accuracy of the obtained SSM prediction was evaluated against ground-based volumetric water content (VWC) measured in the 0–3.8 cm soil layer at multiple points using a TDR meter. The TDR VWC data were preliminarily calibrated against gravimetric measurements in the 0–5 cm soil layer. The obtained data for soil water retention curves in all studied variants were used to determine the range of soil moisture variation. The measured ground-based data for surface roughness generally correlate with the co-pol Gamma-Nought in VV. The data modeled with the surface soil moisture script in Sentinel Hub (SSM-SH) was calibrated using the ground-based data. Incidence angle normalization of Sentinel-1 products improved the relationship between SAR observables and SSM, when expressed as the ratio of soil moisture to total porosity (rVWC). The modeling indicated the highest importance of the optical indices, together with the temporal differences of radar descriptors sensitive to variations in soil moisture over time. Although the applied Random Forest Regression (RFR) model achieved higher accuracy during training (nRMSE of 7.27%, R² of 0.86), the Gaussian Process Regression (GPR) model provided better generalization performance on the independent validation dataset. The results proved the advantages of the joint utilization of temporal Sentinel-1 SAR measurements with Sentinel-2 optical acquisitions to determine SSM in different bare soil conditions for achieving high accuracy. Full article

Triphenyl phosphate (TPHP), a typical organophosphate flame retardant, has been listed as an emerging pollutant, yet its biodegradation remains poorly studied. Herein, an efficient TPHP-degrading marine bacterium, Pseudomonas abyssi RL-WG04, was isolated from mangrove sediments, which could degrade 95.22% of 100 mg/L TPHP within 120 h. RL-WG04 exhibited good tolerance to varied environmental conditions, maintaining over 70% TPHP degradation percentages (100 mg/L, 7 d) across 20–50 °C, pH 7.0–9.0, and salinity 2.0–4.0% (NaCl, w/v). Organic solvents (p-xylene, biphenyl, toluene and ethyl acetate, 0.5% v/v) had a negligible impact, whereas metal ions (Mn²⁺, Fe³⁺, Ca²⁺, Cu²⁺, Mg²⁺, Zn²⁺, and Co²⁺) strongly inhibited degradation, especially at 1 mM. Under optimized conditions, TPHP degradation by RL-WG04 followed the improved Gompertz model (R² = 0.99927). Metabolite identification indicated that RL-WG04 transformed TPHP into phenol but failed to utilize phenol for growth because of the phenol 2-monooxygenase deficiency. Nevertheless, the constructed consortia of RL-WG04 and Pseudomonas sp. RL-LY03 (phenol-degrading bacterium) achieved complete TPHP degradation and cell proliferation. Additionally, RL-WG04 could efficiently remove TPHP (25 mg/kg) from clay and sandy mangrove sediments with 100% and 90.04% removal percentages, respectively. Overall, this work provides novel insights into the fate of TPHP and a potential approach for its remediation. Full article

This study reports the valorization of oil palm empty fruit bunches into cellulose nanocrystals (CNCs) for the removal of the chemical oxygen demand (COD) from industrial wastewater generated by the same processing sector. Cellulose I_β was first isolated through sequential bleaching, delignification, and mercerization, and two hydrolysis routes were evaluated to obtain CNCs: a concentrated acid route (60% v/v H₂SO₄, 50 °C, 60 min) for CNCs-1 and a low-acid, long-duration route (1% v/v H₂SO₄, 80 °C, 12 h) for CNCs-2. Rietveld refinement of the X-ray diffractograms confirmed the polymorphic transition, assigning cellulose I_β to the intermediate materials and cellulose II to the CNC samples, with crystallite sizes of 4.99 nm for CNCs-1 and 5.43 nm for CNCs-2. Attenuated Total Reflectance–Fourier Transform Infrared (ATR-FTIR) spectroscopy analysis showed the progressive removal of lignin and hemicellulose and supported the cellulose I_β to II transition through changes in hydroxyl bonding and crystallinity-related bands. Preliminary adsorption tests showed better COD removal with CNCs-2, which were therefore selected for optimization using a Box–Behnken design with the adsorbent mass, pH, and contact time as variables. The quadratic model was significant (R² = 0.9675; predicted R² = 0.8908), and the maximum COD removal reached 91.47%, decreasing the COD concentration from 2459.0 to 209.85 mg L⁻¹ under the optimum conditions of 0.09 g CNCs-2, pH 3, and 20 min. These results highlight cellulose II nanocrystals derived from oil palm waste as a promising and scalable adsorbent for industrial wastewater treatment. Full article

In this paper, the target compound, 4-hydroxy-3-[[(2-hydroxy-1-naphthalenyl)methylene]amino]benzenesulfonamide (hereafter referred to as HA), was synthesized via the reaction of 2-hydroxy-1-naphthaldehyde with 2-aminophenol-4-sulfonamide in an 86% yield. In methanol–water (v/v, 1:1, pH 5.0 acetate buffer), HA displays a “turn-on” fluorescence response at 531 nm (λex = 411 nm) toward Al³⁺ with high selectivity over 17 common metal ions and 11 anions. The fluorescence intensity is linearly correlated to an Al³⁺ concentration from 1 to 10 µM (R² = 0.999) with a detection limit of 58 nM (3σ/k). Job’s plot and DFT calculations (M06/6-31G) both support a 1:1 binding stoichiometry. Under the tested conditions (with the methanol–water medium having an effective ionic strength equivalent to a low-salinity environment), the probe’s performance was unaffected. In natural aqueous samples (tap water and bottled water), which typically have low salinity (estimated as 0–5‰), Al³⁺ in the samples can also be chelated by the HA probe with a precision of relative standard deviation of less than 1%, and the recovery rate is higher than 90%. The probe exhibited acceptable relative recovery and low standard deviation, demonstrating a rapid and convenient novel method for detecting Al³⁺ in a natural aqueous sample. Full article

The present study examines the physicochemical degradation and elemental contamination of marine distillate diesel fuels, which were stored in land-based tanks in operational conditions. Forty-one (41) samples, in compliance with ELOT ISO 8217:2024 were analyzed for crucial physicochemical properties. Stepwise regression identified magnesium (Mg) (positive) and chromium (Cr) (negative) as significant viscosity predictors (R² = 0.269, p = 0.003, VIF < 2), while calcium (Ca), Phosphorus (P), zinc (Zn), copper (Cu), lead (Pb) and Ferrous (Fe) were excluded due to multicollinearity. Strong correlations (r > 0.85) between element pairs (Cu-Pb) (r = 0.996), Ca-Zn (r = 0.897), and P-Ca (r = 0.888) indicate common sources from lubricant additives (ZDDP) and brass corrosion, with individual correlations recorded for Ca (showing r = 0.679, p < 0.001), P (r = 0.722, p < 0.001), and Zn (r = 0.595, p < 0.001). The results revealed that fuels stored in carbon steel tanks under high-humidity conditions for over six (6) months recorded higher metal loads than those in stainless steel tanks with regular periodic supply. The FAME content in the studied samples ranged from 6.7 to 7.1% v/v and showed no significant correlation with degradation indicators (p > 0.05). The narrow FAME range examined precludes definitive conclusions regarding specific biodiesel effects. The threshold of 0.2 mg/kg, as set by manufacturers’ guidelines to protect injectors, was exceeded in the coastal carbon steel tank samples with eight (8) months of storage under high-humidity conditions and in the coastal carbon steel tank samples with nine (9) months of storage under high-humidity conditions examined. The current study offers a systematic correlation between viscosity and elemental contamination for marine distillate fuels under operational storage conditions regarding real-world samples. Full article

This study developed and validated a stability-indicating high-performance thin-layer chromatography (HPTLC) method for the identification and quantification of gentamicin sulphate in an ointment formulation using silica gel 60 F254 HPTLC plates as the stationary phase and methanol: chloroform: ammonia solution (25%) (1:1:1, v/v/v) as the mobile phase. An ideal solvent ratio, chloroform: methanol (9:1, v/v), was used to dissolve the ointment sample before analysis. According to the guidelines of the International Council for Harmonisation (ICH), the HPTLC method was validated, demonstrating specificity by separating all three bands of gentamicin sulphate without interference from ointment excipients and/or degradation products resulting from photolytic, photolytic and oxidative, oxidative, acidic, and alkaline stress conditions. The findings of the study also revealed that the method has high levels of linearity within the range of 50–300 ng/band (R² ≥ 0.99), with detection and quantification limits of 7.10 ng, and 21.53 ng, respectively. Additionally, the method does not require any sample pre-treatment, such as extraction from the ointment base, making it simple and convenient for the quality control of gentamicin ointments. Full article

Shrimp aquaculture is constrained by opportunistic bacterial pathogens, particularly Vibrio parahaemolyticus, whose proliferation in hatchery systems is shaped by microbial community structure. We evaluated the antagonistic activity and microbiome effects of two native Bacillus-based probiotic consortia (CN5, RS3) applied alone or combined (MIX) in shrimp larval culture water over 30 days, relative to a no-probiotic control. Treatments were assessed using standardized in vitro inhibition assays, 16S rRNA gene (V3–V4) amplicon sequencing, functional inference, and integrative multivariate and structural modeling. All probiotic treatments showed consistently high antagonistic activity against V. parahaemolyticus, whereas the control showed no inhibition. Amplicon profiling indicated treatment-associated microbiome restructuring, with increased Bacillus dominance and reduced relative abundance of Vibrio spp. under probiotic conditions. Multivariate analyses separated probiotic and control groups, and PLS-SEM identified Bacillus dominance as a central driver of antagonistic activity mediated by inferred bioactive functional potential, while water-quality variables had limited direct effects. Probiotics were administered directly to the culture water once daily after routine water exchange to 1 × 10⁶ CFU mL⁻¹ (CN5 or RS3); MIX was applied 1:1 (v/v) at the same total dose. Full article

Phytic acid (PA), owing to its strong acidity and multidentate metal-chelating properties, readily forms multiple adduct/complex ions in mass spectrometry and is prone to pronounced matrix effects, resulting in complicated spectra and compromised sensitivity and quantitative robustness, which poses a major challenge for rapid and accurate PA quantification. Herein, we developed a rapid quantitative method for PA based on trimethylsilyldiazomethane (TMSD) methyl-ester derivatization coupled with paper spray mass spectrometry (PS–MS). PA was derivatized with TMSD to yield the methylated product (PA-Me), and the derivative solution was purified via “post-derivatization nitrogen blow-down followed by water reconstitution”, thereby markedly reducing background interference. In positive-ion mode, the stable sodium adduct ion [PA-Me+Na]⁺ (m/z 851.04) was used as the quantifier, enabling fast quantification with selected ion monitoring (SIM). PS–MS was performed with a 15 μL spotting volume and methanol/water (90/10, v/v, containing 0.1% formic acid) as the spray solvent, allowing rapid analysis without chromatographic separation. The method exhibited good linearity over 0.125–30 μg/mL (R² ≥ 0.9965), with a limit of detection (LOD, S/N = 3) of 0.080 μg/mL and a limit of quantification (LOQ, S/N = 10) of 0.270 μg/mL. The intra-day and inter-day precision values were both < 10% (RSD), and recoveries ranged from 87.2% to 122.4%. This LC-free strategy features low solvent consumption and high analytical throughput, and was validated using rice bran protein and rice bran polysaccharide samples, providing technical support for rapid screening and quality control of PA in complex food/plant matrices. Full article

To address the challenge of purifying bioactive polyphenols from the complex matrix of Ziziphus jujuba Mill. var. spinosa pulp, this study established an integrated purification protocol combining Deep Eutectic Solvent (DES) extraction with macroporous adsorption resin (MAR) enrichment. Among five screened resins, AB-8 exhibited superior selectivity, achieving a maximum adsorption capacity of 62.48 mg polyphenols/g dry resin and a desorption ratio of 83.40%. Kinetic analysis revealed that the adsorption process strictly followed a pseudo-second-order model (R² = 0.999), indicating a mechanism dominated by chemisorption. Through dynamic optimization, optimal column parameters were determined as a loading concentration of 2.4 mg/mL, a flow rate of 1.0 mL/min, and elution with 70% (v/v) ethanol. Structural characterization via UV-Vis and FT-IR confirmed the effective removal of polysaccharide and protein impurities, while High-Performance Gel Permeation Chromatography (HPGPC) indicated a low-molecular-weight distribution (M_w approx. 1073 Da). Furthermore, HPLC-MS profiling definitively identified eight key constituents, including chlorogenic acid, catechin, rutin, and quercetin. Collectively, this work elucidates the adsorption mechanism and provides a scalable, efficient technical foundation for the high-purity preparation of jujube polyphenols. Full article

Shutdown dose rate (SDDR) assessments have been performed for the DEMO tokamak model, including the latest design and environmental configurations. The main objective of this study was to evaluate the shutdown radiation fields and establish dose rate limits to ensure safe personnel access to the Vacuum Vessel (VV) and nearby components. The simulations were based on the DEMO baseline model, further refined with the minor updates of the lower port, equatorial port limiter, and upper port assemblies. The computational approach employed the Monte Carlo particle transport code MCNP for neutron and photon transport calculations, coupled with the activation and decay code FISPACT-II to determine time-dependent decay gamma source terms. The mesh-coupled Rigorous Two-Step (R2Smesh) methodology developed in KIT was applied to achieve spatially resolved decay of photon source distributions and to compute corresponding SDDR 3D maps within the DEMO reactor configuration. The results provide a detailed characterization of the residual radiation environment inside the VV, offering insight into the accumulated activity, shielding performance of different materials, and potential access scenarios for maintenance operations in next-generation fusion devices. Full article

Paracetamol (PAR) and orphenadrine citrate (ORPH) are two active substances commonly used in combination medicinal products, due to the analgesic effect of paracetamol and the muscle relaxant effect of orphenadrine, with a therapeutic indication of mild to moderate acute musculoskeletal pain. The aim of this work is to develop and validate an isocratic HPLC method for the simultaneous determination of PAR and ORPH in tablet formulation. Preliminary experiments showed that an analytical column with a chemically bound phenyl phase was required. A Box–Behnken design (BBD) was utilized to optimize the analytical method for two key responses, PAR asymmetry factor (Asym_PAR) and ORPH capacity factor (k_ORPH), with three numerical factors: percentage of ACN in mobile phase (A); pH (B); and salt concentration in the aqueous solution (C). The optimized method consists of a Pinnacle DB Biphenyl (250 × 4.6 mm) 5 µm column, and a mobile phase of 37%/63% v/v ACN-NaH₂PO4·H₂O in 29 mM aqueous solution, pH = 2.5. The flow rate was set to 1.5 mL/min and detection occurred at 215 nm. After the optimization process the following chromatographic conditions were selected and the method was validated for various ICH parameters covering system suitability, specificity, linearity (R² = 1.00), precision (%RSD ≤ 2), accuracy (98% ≤ %Recovery ≤ 102%), and robustness. Finally, the environmental friendliness of the novel method was assessed by using the Analytical GREEnness (AGREE) metric tool, obtaining a score of 0.67. Full article

The primary objective of the current study is to establish and validate for the first time a method to determine and quantify praziquantel (PZQ) and its main degradation products loaded in poly(methyl methacrylate–co-2-(diethylamino)ethyl methacrylate) P(MMA-co-DEAEMA) microparticles. A high-performance liquid chromatography (HPLC) approach was developed and validated in accordance with the United States Pharmacopeia (USP) guidelines, addressing parameters such as accuracy, linearity, solution stability, precision, specificity, robustness, sensitivity, and system suitability. The method employed a gradient mobile phase consisting of ultrapure water and acetonitrile, flowing at a rate of 1 mL/minute over a Phenomenex Kinetex^® C18 column (5 µm, 100 Å, 250 × 4.6 mm) maintained at 35 °C. Detection was performed at the wavelength of 210 nm using a DAD/UV detector. Samples of the active pharmaceutical ingredient (API) praziquantel, microencapsulated praziquantel, placebo, and a mixture of related substances (A, B, and C) were prepared with 0.5% formic acid in water/ethanol, 45:55 v/v as the diluent, and injected at 20 °C. The method demonstrated a limit of quantification (LOQ) of 0.20 µg/mL for praziquantel and related substances. The method exhibited an excellent linear response, with all correlation coefficients (R²) values exceeding 0.998, which is well above the recommended specified limit of R² > 0.995. Percent recoveries fell within the acceptable range of (95.0–105.0%), and all results indicated a percentage of relative standard deviation (%RSD) ≤ 2.0, indicating a robust methodology. Thus, the proposed HPLC technique proved to be selective, accurate, sensitive, and consistent in analyzing both the material content and its main degradation products. Full article