Search Results (38)

The surface of chalcopyrite was studied by XPS characterization for an unleached chalcopyrite, and, after being leached in an alkaline oxidant medium at room temperature, pH 12.5, and [ClO⁻] 0.34 M, the reaction of enargite presented high selectivity with respect to chalcopyrite, allowing the removal of arsenic from copper concentrates with high arsenic content prior to smelting. Based on the XPS analysis, the original chalcopyrite is composed of a combination of its constituents in different oxidation states, and chalcopyrite has the following stoichiometric formula: Cu(I)_0.85Cu(II)_0.15Fe(II)_0.65Fe(III)_0.35S²⁻_1.5S₂²⁻_0.17S_n0.08²⁻. The unleached chalcopyrite on its surface presents an iron deficiency, which raises the ratio Cu/Fe up to 2, reaching the chalcopyrite Cu/Fe rate in the fifth cycle. The Cu/S ratio of chalcopyrite, 0.5, remains constant at the surface as after the peeling. Surface sulfur shows a decrease in monosulfides, increasing the S_n²⁻/S²⁻ y S₂²⁻/S²⁻ ratio. Chalcopyrite leached with ClO⁻/OH⁻ media generates surface layers with the following intermediate products: Chalcopyrite → CuFe_1-xS₂/CuS_n/Fe³⁺ -OH → Fe³⁺-OH/CuO/SO₄²⁻. Neither sulfur intermediates nor oxidized final products are passivating, allowing the chalcopyrite transformation to progress in depth with increasing reaction time. Full article

Background/Objectives: Anthocyanins, water-soluble flavonoid pigments with critical roles in plant stress resistance, are not naturally accumulated in cultivated tomato (Solanum lycopersicum) due to an incomplete flavonoid metabolism pathway. In contrast, ‘Black Pearl’ tomato exhibits distinct peel color transitions (from indigo rose to deep purple–red) during ripening, making it an ideal model for investigating the regulatory mechanisms of anthocyanin synthesis. A comprehensive strategy was employed to elucidate these mechanisms, involving transcriptomic (Illumina HiSeq), metabolomic (UPLC-MS/MS), and functional analyses of the ‘Black Pearl’ tomato peel across four developmental stages: mature green (S1), coloring (S2), purple immature (S3), and fully ripened (S4). Results: Transcriptome profiling identified 597 core differentially expressed genes (DEGs) associated with anthocyanin accumulation. Temporal analysis indicated that structural genes and activators peaked at S3, whereas repressive MYBs, including SlMYB76 which peaked at S2, exhibited staged expression. In parallel, metabolomic analysis identified 36 metabolites, with cyanidin and pelargonidin derivatives being characterized as the principal pigments. Functionally, SlMYB76 was confirmed to be a negative regulator, as its transient overexpression reduced anthocyanin content and downregulated SlANS. Mechanistically, direct binding and repression of the SlANS promoter by SlMYB76 were confirmed through yeast one-hybrid and dual-luciferase assays. Furthermore, its physical interaction with the bHLH factor SlJAF13 in the nucleus was demonstrated by Y2H, BiFC, LCI, and Co-IP, supporting the formation of a repressive complex that co-regulates SlANS. Conclusions: A novel SlMYB76-SlJAF13-SlANS regulatory module controlling anthocyanin accumulation in the peel of ‘Black Pearl’ tomato was identified. This discovery enhances the current understanding of the tomato flavonoid regulatory network and provides strategic targets for the genetic improvement of fruit color and anthocyanin content through molecular breeding. Full article

The aim of the study was to investigate the effects of different concentrations (0.15, 0.30, and 0.45 mL/L) of essential oils from coriander seeds (Coriandrum sativum), tarragon (Artemisia dracunculus), and orange peels (Citrus sinensis) on biomass, lipid content, and lipid yield of the strains Yarrowia lipolytica Y-1094, Y. lipolytica YB 423, and Y. lipolytica IFP29. The fatty acid composition of the oils produced by the strains was also determined. The highest biomass (5.38 ± 1.80 g/L) and lipid production (0.98 ± 0.42 g/L) were observed in the presence of Y. lipolytica IFP29 and Y. lipolytica YB 423, respectively. The lipid yield showed the highest value at the level of 0.45 mL/L in the presence of the Y. lipolytica Y-1094 strain. The correlation heat map results indicate that 0.45 mL of tarragon affected biomass and lipid content more than the other essential oils used. Y. lipolytica Y-1094 produced higher levels in terms of myristic acid and palmitic acid in all three essential oil sources than the other strains. The highest oleic acid level of all strains was determined in coriander seed essential oil, and the lowest in tarragon essential oil. The oleic acid level of Y. lipolytica Y-1094 was lower than that of the other two strains in all essential oils. Regarding linoleic acid, the oil level did not have a significant effect in the presence of tarragon and orange peel. Full article

Potato (Solanum tuberosum L.) is an important global food crop, being greatly valued for its high carbohydrate content and nutritional profile. In response to the world population’s rapid growth and the increasing need for nutritionally enhanced food quality, potato biofortification has become a key focus of agronomic research. This study investigated the effect of calcium (Ca) biofortification on two potato cultivars (Picasso and Rossi) cultivated in Portugal, assessing its impact on the photosynthetic functioning and the Ca content and distribution of tubers. At the beginning of the tuberization stage, seven foliar applications of CaCl₂ or Ca-EDTA at 12 kg ha⁻¹ were performed. The application of Ca-EDTA led to an increased Ca content in peeled tubers of Picasso (37%) and Rossi (16%), and 88% and 79% in unpeeled tubers, in the same cv. order and as compared to their controls, with Ca predominantly accumulating in the epidermis/peel region. Photosynthetic performance was negatively impacted by the Ca-EDTA treatment in Picasso but not in Rossi, which was reflected in the significant declines in net photosynthesis (P_n) and maximal (F_v/F_m) and actual (F_v′/F_m) photochemical efficiency of photosystem II. Additionally, both genotypes showed negative impacts (greater in Picasso) on the quantum yield of non-cyclic electron transport (Y_(II)) and photochemical quenching (q_L) after five foliar applications. This contrasted with the absence of negative impacts under the use of CaCl₂, which resulted in 17.1% (Picasso) and 29.5% (RFossi) increase in Ca content in peeled tubers, without any significant differences between the unpeeled tubers of both cvs. Moreover, only with CaCl₂, the tuber weight and yield were not negatively impacted. These findings pointed out that, although with a lower Ca increase in the tubers, CaCl₂ was the best suitable option for the Ca biofortification of these cvs. at the applied doses. Full article

To develop solutions to the frequency instability and failure of silicon micromechanical resonant accelerometers, the state characteristics of micromechanical resonant accelerometers are investigated under temperature and vibration stresses. Through theoretical analysis and finite element simulation, the following is found: the Young’s modulus of silicon varies with temperature, causing a resonance frequency shift of −1.364 Hz/°C; the residual stress of temperature change affects the resonance frequency shift of the microstructure, causing it to be 5.43 Hz/MPa (tensile stress) and −5.25 Hz/MPa (compressive stress); thermal expansion triggers the failure of the bonding wire, and, in the range of 10 °C to 150 °C, the peak stress of the electrode/lead bond area increases from 83.2/85.6 MPa to 1.08/1.28 GPa. The failure mode under vibration stress is resonance structure fracture and interlayer peeling. An isolation frame design is proposed for the sensitive part of the microstructure, which reduces the frequency effects by 34% (tensile stress) and 15% (compressive stress) under temperature-variable residual stresses and the maximum value of the structural root mean square stresses by 69.7% (X-direction), 63.6% (Y-direction), and 71.3% (Z-direction) under vibrational stresses. Full article

Nutraceuticals are gaining research interest due to their beneficial potential and their use to counter the impact of emerging contaminants on natural ecosystems. Particularly, during the COVID-19 pandemic, the use of personal hygiene/care products and disinfectants increased significantly. These products contain several substances in their formulations, including surfactants, which have proven to be hazardous to the entire aquatic ecosystem. In the present study, bergamot (Citrus bergamia) peel extract was used as a nutraceutical to counteract the toxicity of sodium lauryl sulphate (SLS), a common anionic detergent with antimicrobial activity. Specimens of Mytilus galloprovincialis, were exposed to SLS (0.01 mg/L), bergamot peels’ extract (BRG: 5 mg/L), and their mixture for 14 days. The cellular and physiological alterations in haemocytes, digestive gland (DG) and gill cells were analysed. The analyses included cell viability of haemocytes and DG cells (trypan blue exclusion assay and the neutral red retention test); the ability of DG cells to regulate their volume (RVD); haemocyte phagocytic activity; expression of genes involved in antioxidant response (Cu/ZnSOD, MnSOD, Hsp70, and CYP4Y) on gills and DG; the energy efficiency of the organism through byssus production; and the measurement of key macromolecules, including total lipid and fatty acid content, total protein, tocopherols and carotenoids, which play a key role in maintaining physiological and metabolic functions in the organism. Overall, significant differences emerged between the control (CTR) and treated groups, with the CTR and BRG groups resembling each other, while the SLS-treated groups showed significant alterations. Meanwhile, the groups exposed to the combination showed a recovery, suggesting the potential beneficial effect of the BRG. Full article

Methyl orange (MO) is an organic synthetic dye widely used in laboratory and industrial applications. In laboratory settings, it serves as an acid–base indicator due to its distinct color change in both acidic and alkaline environments. Industrially, it is primarily utilized in the textile industry for its ultraviolet (UV) absorption properties. However, the discharge and leakage of methyl orange into the environment can cause severe ecological damage and pose potential carcinogenic and teratogenic risks to human health. Therefore, detecting and quantifying the concentration of methyl orange in various matrices is crucial. This study reports the synthesis of graphene quantum dots (GQDs) from orange peel as a precursor, using ethanol and dimethylformamide (DMF) as solvents. Cyan (c-GQDs) and yellow (y-GQDs) graphene quantum dots were synthesized through a bottom-up hydrothermal method. The difference in color is attributed to the redshift caused by the varying ratio of pyridine nitrogen to pyrrole nitrogen. These GQDs exhibited notable optical properties, with c-GQDs emitting cyan fluorescence and y-GQDs emitting yellow fluorescence under UV light. To investigate fluorescence quenching effects, nine commonly used dyes were tested, and all were found to quench the fluorescence of y-GQDs, with methyl orange having the most significant effect. The fluorescence quenching of orange peel-derived GQDs in the presence of methyl orange is attributed to poor dispersion in DMF solution. Additionally, the GQDs possess high specific surface area, abundant surface functional groups, and excellent electronic conductivity, which contribute to their effective fluorescence quenching performance. The average thickness of y-GQDs (the vertical dimension from the substrate upwards) was 3.51 nm, confirming their graphene-like structure. They emitted yellow fluorescence within the wavelength range of 450–530 nm. Notably, a significant linear correlation was found between the concentration of methyl orange and the fluorescence intensity of y-GQDs (regression coefficient = 0.9954), indicating the potential of GQDs as effective sensing materials for organic pollutant detection. Full article

This study explores how varying chlorogenic acid levels (low—yellowish, Y; high—greenish, G) in sunflower proteins (SFs) affect the properties of eugenol-loaded oil-in-water emulsions and the resulting films, while examining the interaction of cellulose nanoparticles (from commercial (CNC) and banana peel sources (CNF)) with the film-forming matrix. This research fills gaps in literature by demonstrating how interactions among proteins, lipids, phenolic compounds, and cellulose nanoparticles influence film properties. The high chlorogenic acid content in SF reduced electrostatic repulsion between protein molecules, causing aggregation, oil droplet flocculation, and increased emulsion viscosity. The mechanical properties of emulsion-based films were significantly lower than those made with SF dispersions. Films made from low chlorogenic acid (yellowish SF) emulsions showed lower tensile strength and Young’s modulus but higher elongation at break compared to those made from high chlorogenic acid (greenish SF) emulsions. Water vapor permeability (WVP) decreased in films containing oil phases, but adding cellulose nanoparticles increased WVP. Despite this, the cellulose nanoparticles could not fully overcome the negative effects of lipid–protein interactions on mechanical properties and WVP. However, films containing eugenol exhibited significant antioxidant activity. The findings provide insights into developing sustainable, active packaging with antioxidant functionality and reduced environmental impact, opening new avenues for applications in food and other sectors requiring eco-friendly materials. Full article

Prolonged and unprotected exposure to the environment explicitly influences the development of hyperpigmented lesions. The enzyme tyrosinase (TYR) is a key target for regulating melanin synthesis. Several bioactive compounds derived from plant extracts have been found to possess potent anti-melanogenesis properties against TYR. In particular, the potential of banana peels from various varieties has garnered interest due to their application in skin hyperpigmentation treatment. A molecular docking study demonstrated interactions between rosmarinic acid, which is predominantly found in all Hom Thong peel extracts, and the active site of TYR (PDB ID: 2Y9X) at residues HIS263, VAL283, SER282, and MET280, with the lowest binding energy of −5.05 kcal/mol, showing the strongest interaction. Additionally, Hom Thong banana peels are rich in phenolic compounds that could inhibit melanin content and tyrosinase activity in both human and mouse melanoma cells. These effects may be attributed to the suppression of gene expression related to melanogenesis, including the regulator gene MITF and pigmentary genes TYR, TRP-1, and DCT, indicating effects comparable to those of the standard treatment groups with arbutin and kojic acid. Our findings indicated the potential of Hom Thong peel extracts as anti-melanogenic agents. Full article

This paper presents the results of a study of layer gradient thermal protection coatings based on NiCrAlY and YSZ obtained by detonation spraying. Modern gas turbines and high-temperature units operate under extreme temperatures and aggressive environments, which requires effective protection of components from wear, corrosion, and thermal shocks. In this study, the use of layer gradient coatings consisting of alternating layers of NiCrAlY and YSZ was investigated with the aim of solving the problem of thermal stress accumulation due to a smooth change in the composition of the layers. Microstructural and phase analysis showed that alternating layers of NiCrAlY and YSZ formed a dense layer gradient structure with clear interphase boundaries and low porosity. Detonation spraying led to a complete transformation of the monoclinic ZrO₂ phase into a tetragonal one, which significantly increased the mechanical strength of the coating and its resistance to thermal shocks. Sample 1D1 demonstrated excellent tribological and corrosion properties in a 3.5% NaCl solution, which can be explained by its higher density and reduced number of pores. Mechanical tests revealed stable values of hardness and wear resistance of the coating, especially for the 1D1 coating. Studies have shown that coatings are resistant to thermal shocks, but thicker layers show a tendency to peel off after thermal cycling. The obtained results indicate high prospects for the use of layer gradient coatings based on NiCrAlY and YSZ for the protection of gas turbine components and other high-temperature installations operating under extreme loads and aggressive environments. Full article

Background/Objective: Although low-methoxy (LM) pectin (polysaccharides extracted from citrus peels) can reduce inflammation by binding to and inhibiting the TLR-2 pathway in animal models and in vitro studies, the anti-inflammatory effects of LM pectin in humans and mood have not been explored to date. The purpose of this study is to assess the role of dietary supplementation with LM pectin in healthy volunteers on inflammatory markers and on mood, specifically anxiety and depression. Methods: We carried out a 4-week dietary intervention with LM citrus pectin on healthy volunteers (N = 14, age 40 ± 16 y, BMI 24.7 ± 3.0 kg/m², sex F 57%) comparing the effects of daily supplementation with 20 g of LM citrus pectin versus 10 g of maltodextrin as the control (N = 15 age 43.2 ± 11 y, BMI 25.18 ± 2.0 kg/m², sex F 66%). The effects on mood and inflammation were also tested with LM pectin at 5 g, 10 g and 15 g (2 weeks each) in an independent cohort of n = 15 healthy volunteers (age 36 ± 21 y, BMI 23.5 ± 2.4 kg/m², sex F 80%). We assessed serum levels of TNF-alpha (downstream from TLR-2 activation), IL-1 beta, IL-6, IL-10, INF-gamma, CRP, zonulin and TLR-2 concentration which were measured using ELISA in blood samples collected at both the baseline and follow-up visits. Validated measures of anxiety and depression were collected at baseline and follow-up. Results: Supplementation with 20 g of LM pectin resulted in decreases in the pro-inflammatory markers TNF-alpha, IL-1 beta, IL-6 and INF-gamma (all p < 0.05) and an increase in anti-inflammatory marker IL-10 (p = 0.01) at the end of the 4 weeks. No such effects were observed in the control group. In addition, a significant drop in anxiety scores (from 8.38 to 4.46, p < 0.006) was found with the 20 g/day intervention but not in the control arm. In the dose–response study, anti-inflammatory effects were seen only at 15 g for TNFα (p < 0.003) and a suggestive increase in IL-10 (p = 0.08), alongside a drop in TLR-2 (p < 0.027). No significant anti-inflammatory effects were observed at 5 g and 10 g doses of LM pectin supplementation. Significant dose-dependent drops in both anxiety and depression scores were found with 10 g (p < 0.001) and 15 g per day (p < 0.0002). Conclusions: The current study identifies anxiety-reducing and anti-inflammatory effects of supplementation with 15 g/day LM pectin in healthy humans. Further research is needed to elucidate the precise mechanism and to validate the efficient dose and minimum duration of supplementation. Full article

To investigate the impact of Al and Nb elements on the formation of a protective oxide layer on the surface of Fe-35Ni-20Cr-xAl-yNb (x = 0, 2, 4, 6 wt.%; y = 0, 1, 2 wt.%) alloys, their oxidation behavior was examined at 1000 °C, 10⁻¹⁷ atm. and 10⁻²⁵ atm. oxygen pressure, and the oxidation mechanism was analyzed by Factsage and Pandat calculations. Enhancing the Al content at 10⁻¹⁷ atm. inhibited the generation of FeCr₂O₄ on the alloy surface and increased the Al content in the M₂O₃ layer. When the Al content exceeded 6 wt.%, the oxide film partially peeled off. It was found that the addition of Nb increased the activity of Cr and Al and decreased the activity of Ni and Fe and promoted the formation of Al₂O₃, and the appearance of Nb₂O₅ in the subsurface layer increased the density of the oxide film. In addition, under an oxygen pressure of 10⁻²⁵ atm., the only protective layer on the surface of the alloy comprised of Al₂O₃. The experimental results demonstrated that the Fe-35Ni-20Cr-4Al-2Nb alloy generated a continuous and dense Al₂O₃ protective film, and the reduction in oxygen pressure and the addition of Nb elements were favorable for selective external oxidation of Al₂O₃. Full article

Nowadays, there is considerable attention toward the use of food waste from food processing as possible sources of compounds with health properties, such as anticancer activity. An example is tomato processing, which is responsible for generating a remarkable amount of waste (leaves, peel, seeds). Therefore, our goal was to evaluate the potential anticancer property of tomato extracts, in particular “Datterino” tomato (DT) and “Piccadilly” tomato (PT), and to study their phytochemical composition. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) results showed that these extracts are rich in alkaloids, flavonoids, fatty acids, lipids, and terpenes. Furthermore, their potential anticancer activity was evaluated in vitro by MTT assay. In particular, the percentage of cell viability was assessed in olfactory ensheathing cells (OECs), a particular glial cell type of the olfactory system, and in SH-SY5Y, a neuroblastoma cell line. All extracts (aqueous and ethanolic) did not lead to any significant change in the percentage of cell viability on OECs when compared with the control. Instead, in SH-SY5Y we observed a significant decrease in the percentage of cell viability, confirming their potential anticancer activity; this was more evident for the ethanolic extracts. In conclusion, tomato leaves extracts could be regarded as a valuable source of bioactive compounds, suitable for various applications in the food, nutraceutical, and pharmaceutical fields. Full article

The improvement of the performance of asphalt mixtures has been studied by scholars. This research proposes a new asphalt–mineral interface formation method, which is a pre-wet bitumen–mineral mixture. The formation process of the pre-wet asphalt–mineral interface was simulated by molecular dynamics simulation software. The diffusion coefficient, concentration distribution, and interfacial energy of the asphalt on the surface of the pre-wet mineral material and non-pre-wet mineral material were compared and analyzed. The simulation results show that the mineral surface diffusion rate of the asphalt after pre-wetting is increased by more than 50%, and the concentration in the X, Y, and Z directions is reduced by 0.8%, 4.6%, and 7.8%, respectively. At the same time, the interface energy between the bitumen and the pre-wet mineral was increased by more than 8%. The results of the molecular dynamics model are verified based on the surface energy theory and contact angle test. The experimental results show that the contact angle of the asphalt is smaller and the diffusion performance is better after pre-wetting. At the same time, the interface adhesion work between the asphalt and wet mineral surface increased by 4.3% in a dry environment, and the peeling work decreased by 41.1% in a water environment. Therefore, the author believes that the pre-wetting technology of the asphalt mixture has a certain feasibility and practicability. Full article

Pomegranate (Punica granatum L.) is well known for its high content of bioactives, including polyphenols, flavonoids, and tannins, which have been shown to exhibit a wide range of biological activities, such as antioxidant, antimicrobial, and anticancer effects. It is worth noting that the majority of these molecules are found in the peels, which are usually disposed of after processing, causing a significant amount of waste, amounting to more than 3.6 million t/y. This work investigates microwave-assisted extraction (MAE) in water for the recovery of antioxidants from pomegranate peels (PP), including the optimisation of temperature and extraction times. The total phenolic, anthocyanin, flavonoid, and tannin contents of the recovered extracts were determined, as well as their antioxidant activities, which were found to be 356.35 mgGAE/gExtr, 303.97 µgCy3G/gExtr, 37.28 mgQE/gExtr, 56.48 mgGAE/gExtr, and 5.72 mmolTE/gExtr, respectively (according to the adopted reference). All results were compared with those obtained using a conventional protocol. In addition, the potential for water recycling by means of downstream nanofiltration in optimised MAE was investigated, leading to overall water reuse of approx. 75%. Power consumption (20.92 W/mgGAE) and common green metrics, Reaction Mass Efficiency (RME), E-Factor, and the Process Mass Intensiti/efficiency (PMI, PME), were considered in evaluating the proposed PP valorisation strategy. Finally, the biological activities of the main products were assessed. The antimicrobial properties of the PP extracts against three Gram-positive and three Gram-negative bacteria and their antiproliferative activity towards human cancer cells were tested. S. aureus bacteria was the most susceptible to the PP extracts. All tested products displayed antiproliferative activity against HeLa cells when higher concentrations were tested, with D-PP/NF (obtained from dried PP and sequential nanofiltration) being the most effective. This result was also confirmed via clonogenic analysis, which generally indicated the possible anti-cancer activity of pomegranate peel extracts obtained using this green approach. Full article