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Application of Brassica juncea and Raphanus sativus Sprout Extracts as Active Agents in Chitosan-Based Edible Coatings: Evaluation of Physicochemical and Biological Properties
No full textThe use of natural bioactive compounds in edible coatings provides a sustainable approach to reducing food spoilage and meeting consumer demand for safer food preservation. In this study, bioactive extracts from Brassica juncea (green mustard, GM) and Raphanus sativus (radish tango, RT) sprouts were encapsulated into zein/chitosan (Z/CH) microparticles (MPs) using a complex coacervation–based encapsulation approach. The encapsulated microparticles (MPs), characterized by FTIR and UV-Vis spectroscopy, demonstrated a high loading efficiency of up to 90% and maintained their antioxidant activity for up to 168 h. TGA and SEM tests confirmed that the edible films produced by incorporating these microparticles (MPs) into polyvinyl alcohol (PVA) and chitosan (CH) matrices had a more uniform microstructure and enhanced heat stability. The Z/CH/RT6:PVA (1:2) and Z/CH/GM6:CH (1:1) formulations of the films showed significant antioxidant and antibacterial action, with up to 22.4% DPPH inhibition and a 1-log decrease in Salmonella enterica CFU, respectively. Overall, the results underscore the promise of sprout-derived microparticles as components for developing active, biodegradable packaging films with improved functional properties
Unified Fixed-Point Theorems for Generalized p-Reich and p-Sehgal Contractions in Complete Metric Spaces with Application to Fractal and Fractional Systems
No full textThis paper introduces new generalized forms of contractive mappings in the framework of complete metric spaces. By extending the classical Reich and Sehgal contractions to their iterated counterparts in Singh’s sense, we establish unified fixed-point theorems that ensure both existence and uniqueness under constant and variable contractive parameters. The proposed p-Reich and p-Sehgal contractions encompass several well-known results, including those of Banach, Kannan, Chatterjea, Reich, and Sehgal, as special cases. Convergence of the associated Picard iterative process is rigorously analyzed, revealing deeper insights into the iterative stability and asymptotic behavior of nonlinear mappings in metric spaces. The practical utility of our unified fixed-point theorems is illustrated through concrete applications in fractal and fractional calculus
Chitosan/Cellulose Functional Composite Hydrogel as Adsorbent for the Removal of Cu(II) from Aqueous Solutions in Dynamic Adsorption System
No full textWater contamination by heavy metals remains a major global challenge, requiring efficient, sustainable, and low-cost remediation materials. Chitosan and cellulose are recognized as effective biosorbents due to their high affinity toward metal ions, biodegradability, and availability. However, their individual limitations motivate the design of composite with enhanced properties. In this study, chitosan/cellulose composite hydrogel beads crosslinked with glutaraldehyde (CHB-CF-GLA) were synthesized and evaluated for Cu(II) removal under batch and dynamic conditions. The composite was characterized by FESEM-EDS, ATR-FTIR, XRD, swelling analysis, and determination of pHpzc to elucidate its structural and physicochemical features. Batch experiments optimized pH, initial Cu(II) concentration, and adsorption capacity, while non-linear kinetic and isotherm models described the adsorption mechanism. The adsorbent exhibited good stability and reusability over multiple cycles. Fixed-bed column studies demonstrated that increasing bed height prolonged breakthrough and exhaustion times, while higher influent concentrations and flow rates led to earlier column saturation. The experimental breakthrough curves were well described by the Thomas and Yoon–Nelson models, whereas the Adams–Bohart model showed limited applicability. COMSOL Multiphysics 3.5 simulations validated the experimental data and predicted column performance. Overall, CHB-CF-GLA is an efficient and functional adsorbent with strong potential for continuous Cu(II) removal in water treatment applications
Efficient cobalt-based bimetallic nanocatalysts with iron, manganese, molybdenum, and nickel on reduced graphene oxide for oxygen evolution reaction
No full textNanosized particles of CoM were deposited on reduced graphene oxide (CoM/rGO), where M represents secondary transition metal of Fe, Mn, Mo, and Ni, to obtain five different electrodes. Morphological and structural examination with SEM, TEM, and XRD confirmed the successful formation of nano-sized CoM/rGO amorphous layers, while the XPS survey confirmed the presence of cobalt nanoparticles in the form of Co3+in the case of all samples. All five electrodes showed excellent oxygen evolution reaction (OER) activity in alkaline media, where the current densities at 2 V decreased in the following order: CoMo/rGO (175.6 mA cm−2) > Co/rGO > CoMn/rGO > CoFe/rGO > CoNi/rGO (80.2 mA cm−2). In addition to delivering the highest OER current density, CoMo/rGO showed the lowest overpotential of 370 mV at 10 mA cm−2and the lowest onset potential of 1.5 V during OER. These imply that CoMo/rGO has the best OER activity, followed by CoFe/rGO, CoMn/rGO, while somewhat lower OER activity was obtained for Co/rGO and CoNi/rGO electrodes. All of these CoM/rGO electrodes, especially CoMo/rGO, could be good candidates for replacing the OER electrocatalysts that employ rare metals, such as IrO2, in alkaline media
Utilization of Organic Solvents for the Recycling of Waste Wooden Railroad Ties
No full textWooden waste railroad ties preserved with coal tar creosote oil represent a specific source of polluting substances. The aim of this study was to investigate and compare extraction capacity due to solvent extraction of fifteen frequently used organic solvents for the purpose of decontamination treatment of waste wooden railroad ties, while recovering wood for reuse. Pure organic solvents, ethanol 96%, propan-2-ol, deionized water, dichloromethane, acetone, n-hexane, mixture n-hexane/acetone (V/V = 1/1), cyclohexane, methanol, N,N-dimethyl formamide, toluene, ethyl acetate, acetonitrile, amyl acetate, medical gasoline, n-pentane and n-butyl acetate were for leaching pollutants from waste railroad ties. The highest extraction capacity was achieved using dichloromethane, where 7.50 to 7.89 wt.% of total sixteen polycyclic aromatic hydrocarbons were extracted from waste railroad tie chips. The most promising solvents for the treatment exhibited extraction efficiency which decreases in a series dichloromethane > n-hexane/acetone > acetone > methanol > ethanol 96% > propan-2-ol > cyclohexane > toluene > n-hexane. Solvent extraction represents a novel approach for treatment of wooden waste railroad ties. The experiments are based on the search for a management process for the treatment of wood waste railroad ties that is simple, low energy consumption, efficient and could potentially be applied for large scale
Urea-assisted vs. conventional precipitation for the synthesis of sepiolite-zirconium oxide/hydroxide composites: Influence on the physicochemical properties and phosphate adsorption
No full textUrea-assisted precipitation could be a promising alternative to usual ammonia precipitation for preparing sepiolite–zirconium oxide/hydroxide composites with improved properties for removing phosphate from water. This study investigates the effects of synthesis temperature and duration on the properties of composites obtained by urea-assisted precipitation and their phosphate adsorption performance at pH 4 and 8. Urea-assisted precipitation was carried out at 95, 120, and 180 °C for 3 and 18 h, while ammonia precipitation was performed at room temperature. The results showed that the highest temperature and longest synthesis time (180 °C, 18 h) led to the most homogeneous distribution of ZrO2 particles; however, the increase in solution pH (∼8.5) and the formation of crystalline particles negatively affected the adsorption capacity. Lowering the synthesis temperature and duration slowed down urea hydrolysis, reduced both the solution pH and the point of zero charge of the composites, and decreased the tendency towards ZrO2 crystallization, which was favorable for phosphate adsorption. Nevertheless, urea-assisted syntheses did not significantly enhance the adsorption capacity compared to conventional precipitation at pH ∼12, most likely due to the stronger condensation of Zr–OH groups at elevated temperatures. XPS analysis confirmed the involvement of both inner- and outer-sphere complexes in the adsorption mechanism at pH 4. The ATR-FTIR analysis supported the formation of inner-sphere complexes during phosphate adsorption at both pH 4 and pH 8. Desorption experiments indicated slow phosphate release, supporting the presence of strong interactions between phosphate ions and surface functional groups. These findings provide valuable insights into the control of structure and adsorption performance of sepiolite–ZrO2 composites through optimization of the urea-assisted precipitation process
Insulin-like growth factor 1 (IGF-1)-induced changes in cardiac inducible nitric oxide synthase (iNOS) in obese rats
No full textIntroduction: The role of insulin-like growth factor 1 (IGF-1) in preserving cardiovascular (CV) health, a well-established fact, cannot be overstated. IGF-1 affects inducible nitric oxide synthase (iNOS) activity, contributing to metabolic homeostasis by promoting insulin and glucose metabolism. Excessive iNOS production is involved in the occurrence and progression of insulin resistance and CV diseases (CVD). This study aimed to assess the in vivo impact of IGF-1 on the activity and gene expression of iNOS in the hearts of obese rats, through the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Methods: Male adult Wistar rats were fed a standard (Control) or a high-fat (HF) diet for 12 weeks. After the 12th week, half of the Control and HF rats received a single dose of IGF-1 (50 μg/kg, i.p.), while the other half was placebo-treated, and after 24 h the animals were euthanized. Results: The in vivo administration of IGF-1 led to a significant increase in nitric oxide (NO), iNOS gene and protein expression, endothelial nitric oxide synthase (eNOS) gene, ERK1/2, and nuclear factor kappa B (NFkB) levels in Control rats. In contrast, HF rats showed a decrease in NO, iNOS protein, and gene, eNOS gene, endothelin-1 and NFkB levels after IGF-1 treatment. Notably, the level of ERK1/2 in HF rats increased following IGF-1 treatment. These results underscore the significant impact of IGF-1 on iNOS activity in obese rat hearts. Discussion: Our findings suggest that the treatment of obese rats with IGF-1 could have significant implications for cardiac function, particularly in the context of obesity, by regulating cardiac iNOS
Word embeddings as autonomous predictors in materials design—the effect of inherent variability on information transfer
No full textWe propose that word embeddings of atoms derived from scientific literature are revisited as autonomous machine learning predictors in materials design. If static word embeddings encode comprehensive physicochemical information, joined embeddings of chemical elements constituting a chemical compound represent a viable source of physicochemical knowledge. Nevertheless, static word embeddings are susceptible to variability due to information heterogeneity within training material. We analysed whether variability occurs in embeddings affiliated with physicochemical entities, including explicit atoms, and whether it affects therein-encoded domain-specialized information or inhibits the information transfer. Results demonstrate the substantial variability in individual atomic embeddings, which is highly dependent on vocabulary terms selected for language modelling. Regardless, variability does not obstruct the mapping of materials' composite predictors into physicochemical properties when joined atomic embeddings are implemented within a regression model estimating the compound stability by predicting its formation energy. Moreover, the encoded information and the model's predictive performance maintained stability following compound vector calibration via dimensional reduction. Scientific contribution The magnitude of variability in word embeddings of physicochemical entities, including chemical elements, occurring due to information heterogeneity in complementary training material of materials science, chemistry, and physics scientific literature was observed and quantified. The research shows that notable variability of vectorial representations of chemical elements does not obstruct the underlying statistical properties, nor does it inhibit the information transfer. Accordingly, regardless of their origin, conjoined atomic embeddings representing chemical compounds facilitate stable predictive performance when implemented within a regression model
A systematic approach to designing the sustainability indicator sets for local spatial planning in Serbia
No full textDespite considerable efforts invested in design of sustainability indicators (SI) capable of pointing out and measuring the key features of spatial phenomena and estimate sustainability of the planned outcomes, their consistency, relevance and practical usefulness often remain unsatisfactory. Therefore, improvement, proper implementation, and evaluation are crucial for their further application. The presented study aims to improve this situation in Serbia and provide a context-specific contribution to general understanding of the subject. Building on fundamental definitions, concepts and models of sustainable development, it introduces a systematic approach to examining the structure and correspondence of Serbia’s two principal SI sets (SDI and SDS), applicable also in similar contexts. Analysis of inherent and contextual challenges, sets’ structures (SDI: 4 sectors, 40 themes, 204 indicators; SDS: 5 goals, 37 objectives, 106 indicators), conceptual coherence and applicability, highlights the critical importance of adequate formulation of sectors/goals and themes/objectives for ensuring relevance and effectiveness, and provides directions for sets’ improvement and possible integration. The study also proposes a self-regulated meta-evaluation framework, optimised for Serbia yet adaptable to similar environments, to guide sets’ future applications and integration. Additionally, several general guidelines, useful for sustainability assessment, emerged from the research, as well
Nanoemulsion-derived AlPO₄ ceramics: Densification and phase behavior under field-assisted sintering
No full textAn aluminum phosphate powder (AlPO4) was synthesized using a modified Ouzo nanoemulsion technique. Monolithic AlPO4 ceramics were subsequently produced via a field-assisted sintering technique (FAST) at temperatures 1300 °C and 1400 °C. Both the powder and sintered samples were comprehensively characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Structural characterization of the field-assisted sintered samples revealed stabilization of the high-temperature orthorhombic phase, which may have occurred due to the presence of oxygen vacancies. Mechanical and thermal characterizations of the sintered samples were also performed. Across various thermal treatments, the high-temperature orthorhombic phase gradually transformed to a tridymite monoclinic structure due to temperature-induced atomic displacements caused by shifting and tilting of adjacent layers of rigid AlO4 and PO4 tetrahedra. This study reveals that pressure-dependent polymorphism reflects temperature-dependent phase stability, influenced by external energy inputs from the applied current, which modulates structural rearrangements. The results demonstrate that the modified Ouzo nanoemulsion synthesis method is a highly effective technique for producing AlPO4 powders with favorable sintering properties