Search Results (1,273)

Foliar fertilization is an effective practice that improves both the yield and quality of maize, a crop with high and specific micronutrient demands. This study hypothesized that foliar application of Fe, Cu, Mn, Mo, Zn and B would improve grain size and quality in GS210 maize compared to the control. The single-factor field experiment was conducted in 2023–2024 on Haplic Cambisol (Eutric) soil, under a variety of meteorological conditions. The application of Zn and B fertilizers significantly increased the soil plant analysis development (SPAD) index. Yield components (number of grains per ear, thousand-grain weight) and grain yield increased significantly following Zn foliar application compared to the control. Zn application increased grain yield by 0.59 t ha⁻¹ and 0.49 t ha⁻¹ in 2023 and 2024, respectively. Smaller but beneficial effects were observed with Cu and B applications. In contrast, the effects of fertilization with other micronutrients (Fe, Mn, Mo) were less pronounced than anticipated. Biochemical analyses revealed that foliar fertilization with Fe, Cu and Mo increased total phenolic content and antioxidant capacity, while Fe and Mo enhanced carotenoid accumulation, and Cu and B significantly influenced grain color parameters. The study highlights the potential of foliar fertilization to improve maize performance and grain quality, despite possible antagonisms between micronutrients. Full article

This study investigates the effects of copper nanoparticles (CuNPs) on KRT19 gene expression in four breast cancer cell lines (MDA-MB-231, MDA-MB-468, MCF7, and T47D), representing triple-negative and luminal subtypes. Using cytotoxicity assays, quantitative RT-PCR, and bioinformatics tools (STRING, g:Profiler), we demonstrate subtype-specific, dose-dependent KRT19 suppression, with epithelial-like cell lines showing greater sensitivity. CuNPs, characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM) with a mean size of 179 ± 15 nm, exhibited dose-dependent cytotoxicity. Bioinformatics analyses suggest KRT19′s potential as a biomarker for CuNP-based therapies, pending in vivo and clinical validation. These findings highlight CuNPs’ therapeutic potential and the need for further studies to optimize their application in personalized breast cancer treatment. Full article

Background: Cucurbitacin E (CuE), a natural tetracyclic triterpenoid compound extracted from the melon stems of Cucurbitaceae plants, has been reported to exhibit anti-inflammatory and anti-cancer properties, along with the ability to enhance cellular immunity. However, its role and molecular mechanism in regulating lipid metabolism and adipogenesis remain unclear. This study aims to investigate the potential anti-adipogenic and anti-obesity effects of CuE in 3T3-L1 adipocytes. Materials and Methods: 3T3-L1 preadipocytes were cultured and induced to differentiate using a standard adipogenic cocktail containing dexamethasone, 3-isobutyl-1-methylxanthine (IBMX), and insulin (DMI). CuE was administered during the differentiation process at various concentrations. Lipid accumulation was assessed using Oil Red O staining, and cell viability was evaluated via the MTT assay. To determine whether CuE induced apoptosis or necrosis, flow cytometry was performed using annexin V/PI staining. Additional molecular analyses, such as Western blotting and RT-PCR, were used to examine the expression of key adipogenic markers. Results: Treatment with CuE significantly reduced lipid droplet formation in DMI-induced 3T3-L1 adipocytes in a dose-dependent manner, as shown by decreased Oil Red O staining. Importantly, CuE did not induce apoptosis or necrosis in 3T3-L1 cells at effective concentrations, indicating its safety toward normal adipocytes. Moreover, CuE treatment downregulated the expression of adipogenic markers such as PPARγ and C/EBPα at both mRNA and protein levels. Discussion: Our findings suggest that CuE exerts a non-cytotoxic inhibitory effect on adipocyte differentiation and lipid accumulation. This anti-adipogenic effect is likely mediated through the suppression of key transcription factors involved in adipogenesis. The absence of cytotoxicity supports the potential application of CuE as a safe bioactive compound for obesity management. Further investigation is warranted to elucidate the upstream signaling pathways and in vivo efficacy of CuE. Conclusions: Cucurbitacin E effectively inhibits adipogenesis in 3T3-L1 adipocytes without inducing cytotoxic effects, making it a promising candidate for the development of functional foods or therapeutic agents aimed at preventing or treating obesity. This study provides new insights into the molecular basis of CuE’s anti-obesity action and highlights its potential as a natural lipogenesis inhibitor. Full article

A 12-membered pyridinophane scaffold containing two pyridine and two tertiary amine residues is examined as a prototype ligand (^tBuN4) for supporting nitrene transfer to olefins. The known [(^tBuN4)M^II(MeCN)₂]²⁺ (M = Mn, Fe, Co, and Ni) and [(^tBuN4)Cu^I(MeCN)]⁺ cations are synthesized with the hexafluorophosphate counteranion. The aziridination of para-substituted styrenes with PhI=NTs (Ts = tosyl) in various solvents proved to be high yielding for the Cu(I) and Cu(II) reagents, in contrast to the modest efficacy of all other metals. For α-substituted styrenes, aziridination is accompanied by products of aziridine ring opening, especially in chlorinated solvents. Bulkier β-substituted styrenes reduce product yields, largely for the Cu(II) reagent. Aromatic olefins are more reactive than aliphatic congeners by a significant margin. Mechanistic studies (Hammett plots, KIE, and stereochemical scrambling) suggest that both copper reagents operate via sequential formation of two N–C bonds during the aziridination of styrene, but with differential mechanistic parameters, pointing towards two distinct catalytic manifolds. Computational studies indicate that the putative copper nitrenes derived from Cu(I) and Cu(II) are each associated with closely spaced dual spin states, featuring high spin densities on the nitrene N atom. The computed electrophilicity of the Cu(I)-derived nitrene reflects the faster operation of the Cu(I) manifold. Full article

Enhancing damage tolerance and wear resistance in Al–Si-based alloys under thermomechanical stress remains a key challenge in lightweight structural applications. This study investigates the microstructural and tribomechanical behavior of hypoeutectic Al–Si–(Cu)–Mg alloys with varying Cu:Mg ratios (3:1 vs. 1:3) under a T6 heat treatment. Alloys A and B, with identical Si contents but differing Cu and Mg levels, were subjected to multiscale microstructural characterization and mechanical and wear testing at 25 °C, 150 °C, and 250 °C. Alloy A (Cu-rich) exhibited refined α-Al(FeMn)Si phases and homogeneously dissolved Cu in the Al matrix, promoting lattice contraction and dislocation pinning. In contrast, Alloy B (Mg-rich) retained coarse Mg₂Si and residual β-AlFeSi phases, which induced local stress concentrations and thermal instability. Under tribological testing, Alloy A showed slightly higher friction coefficients (0.38–0.43) but up to 26.4% lower wear rates across all temperatures. At 250 °C, Alloy B exhibited a 25.2% increase in the wear rate, accompanied by surface degradation such as delamination and spalling due to β-AlFeSi fragmentation and matrix softening. These results confirm that the Cu:Mg ratio critically influences the dominant hardening mechanism—the solid solution vs. precipitation—and determines the high-temperature performance. Alloy A maintained up to 14.1% higher tensile strength and 22.3% higher hardness, exhibiting greater shear resistance and interfacial stability. This work provides a compositionally guided framework for designing thermally durable Al–Si-based alloys with improved wear resistance under elevated temperature conditions. Full article

The present study examines the structure, properties and use of complex-alloyed hypereutectic aluminium-silicon alloys, emphasising the control of the morphology of primary silicon via treatment with various modifiers as well as their effects on its shape and distribution. Furthermore, this study reviews the experimental work related to the simultaneous modification of primary and eutectic silicon, which leads to the conclusion that favourable results can be obtained by complex modification treatment involving first- and second-type modifiers. After being cast, the AlSi18Cu3CrMn and AlSi18Cu5Mg non-standardised piston alloys are subjected to T6 heat treatment intended to enhance their mechanical performance, harnessing the full potential of the alloying elements. A microstructural analysis of the shape and distribution of both primary and eutectic silicon crystals following heat treatment was employed to determine their microhardness. Full article

The effect of severe plastic deformation during milling and conventional and Spark Plasma Sintering (SPS) on the wt. % microstructural, structural, thermal, magnetic, and mechanical properties of the Al–16 wt. % Mn–7 wt. % Cu alloy was studied. A milling process for up to 24 h (A24) leads to microstructure refinement and the presence of Al, Mn, and Cu solid solutions. The energy dispersive spectroscopy (EDS) analysis reveals the existence of Cu–Al, Mn–Al, and Al–Mn enriched particles. The powders exhibit weak ferromagnetism and an exchange bias (EB) behaviour that decreases with increasing milling time. The Ms values fitted using the law of approach to saturation (LAS) are comparable to the experimental values. The exothermic and endothermic peaks that appear in the differential scanning calorimetry (DSC) scans in the 500–900 °C range on heating/cooling are related to different phase transformations. The crystal structure of the A24 powders heated up to 900 °C (A24_900 °C) consists of a dual-phase microstructure of Al₂₀Cu₂Mn₃ nanoprecipitates (~28%) and Al matrix (~72%). The sintering of the A24 powders at 500 °C for one hour (A24S) leads to the precipitation of Al₆Mn, Al₂Cu, and the Al₂₀Cu₂Mn₃ T-phase into the Al-enriched matrix. In contrast, the consolidation by SPS (A24SPS) leads to a mixture of an Al solid solution, Al₆Mn, T-phase, and α-Mn with an increased weight fraction of the T-phase and Al₆Mn. The sintered samples exhibit the coexistence of a significant PM/AFM contribution to the M-H curves, with increasing Hc and decreasing EB. A higher microhardness value of about 581 HV is achieved for the A24SPS sample compared to those of the A24 (68 HV) and A24S (80 HV) samples. Full article

The regulation of the active sites of a catalyst is important for its application. Herein, a series of Ag₁Cu_x/SBA-15 catalysts with different molar ratios of Ag to Cu were synthesized via the impregnation method, and the active sites of Ag₁Cu_x were regulated via various pretreatment conditions. These as-prepared Ag₁Cu_x/SBA-15 catalysts were characterized by many technologies, and their catalytic performance was estimated through CO catalytic oxidation. Among these catalysts, Ag₁Cu_0.025/SBA-15, with a Ag/Cu molar ratio of 1:0.025 and pretreated under the condition of 500 °C O₂/Ar for 2 h, followed by 300 °C H₂ for another 2 h, presented optimal CO degradation performance, which could realize the oxidation of 98% CO at 34 °C (T₉₈ = 34 °C). Meanwhile, Ag₁Cu_0.025/SBA-15 also displayed great reusability. Characterization results, such as X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectra (UV-vis DRS), temperature-programmed H₂ reduction (H₂-TPR), and physical adsorption, suggested that the optimal catalytic performance of Ag₁Cu_0.025/SBA-15 was ascribed to its high interspersion of Ag nanoparticles, better low-temperature reduction ability, the interaction between Ag and Cu, and its high surface area and large pore volume. This study provides guidance for the regulation of active sites for low-temperature catalytic degradation. Full article

The efficient simultaneous removal of NO_x and CO from sintering flue gas under low-temperature conditions (110–180 °C) in iron and steel enterprises remains a significant challenge in the field of environmental catalysis. In this study, we present an innovative strategy to enhance the performance of CuSmTi catalysts through silver modification, yielding a bifunctional system capable of oxygen structure regulation and demonstrating superior activity for the combined NH₃-SCR and CO oxidation reactions under low-temperature, oxygen-rich conditions. The modified AgCuSmTi catalyst achieves complete NO conversion at 150 °C, representing a 50 °C reduction compared to the unmodified CuSmTi catalyst (T_100% = 200 °C). Moreover, the catalyst exhibits over 90% N₂ selectivity across a broad temperature range of 150–300 °C, while achieving full CO oxidation at 175 °C. A series of characterization techniques, including XRD, Raman spectroscopy, N₂ adsorption, XPS, and O₂-TPD, were employed to elucidate the Ag-Cu interaction. These modifications effectively optimize the surface physical structure, modulate the distribution of acid sites, increase the proportion of Lewis acid sites, and enhance the activity of lattice oxygen species. As a result, they effectively promote the adsorption and activation of reactants, as well as electron transfer between active species, thereby significantly enhancing the low-temperature performance of the catalyst. Furthermore, in situ DRIFTS investigations reveal the reaction mechanisms involved in NH₃-SCR and CO oxidation over the Ag-modified CuSmTi catalyst. The NH₃-SCR process predominantly follows the L-H mechanism, with partial contribution from the E-R mechanism, whereas CO oxidation proceeds via the MvK mechanism. This work demonstrates that Ag modification is an effective approach for enhancing the low-temperature performance of CuSmTi-based catalysts, offering a promising technical solution for the simultaneous control of NO_x and CO emissions in industrial flue gases. Full article

The reprocessing of metallurgical wastes to recover much-needed metals such as copper not only ensures an adequate supply of metals but also contributes to the cleaning of the environment. A copper smelter in Namibia accumulated significant amounts of spent refractory bricks that are enriched with metal values including copper. This supposedly waste material can potentially serve as a supplement to the ore concentrate, as a smelter feedstock for this toll smelter. Representative samples of crushed bricks, designated as Sample 1 and Sample 2, were used for mineralogical characterisation and flotation test work. The assays for Sample 1 and Sample 2 were 14% Cu and 18% Cu, respectively. Microscopy results identified various copper phases including metallic Cu, bornite, malachite and chalcopyrite. Batch flotation tests were conducted to investigate the effect of grind size (P₈₀ of 53, 75 and 106 μm), pulp pH (natural pulp pH, 10, 10.5 and 11) and collector (potassium amyl xanthate, PAX) dosage (70, 100 and 130 g/t) on the recovery of copper, concentrate grade and weight recovery. In some tests, a co-collector (dithiophosphate, DTP) and sulphidiser (Na₂S) were also added in the quest to maximise the recovery of copper. Based on the test conditions investigated in this study, the grind size is the key variable affecting the recovery of copper. The best copper recovery of 86% (with a weight recovery in the range of 42 to 45% (w/w) and concentrate grade of 37% Cu) was achieved for the finest grind size of 53 μm. The reagent suite that yielded the best recovery was 70 g/t PAX with no addition of the sulphidiser while the pH was 10. There is scope for developing the process routes to recover other valuable metals such as iron, lead and zinc that are also in the spent bricks, as well as potential reuse of the spent bricks (after recovering valuable metals) to make new refractory bricks. Full article

This study demonstrated the successful recovery of zinc, lead, and copper collective concentrates from historical metal-bearing mine tailings (sulfide–polymetallic ore with a composition of 7.38% Zn, 1.45% Pb, and 0.49% Cu) using froth flotation techniques, which were originally developed during uranium ore mining. Froth flotation techniques were used to justify suitability for recovering metals. The effects of a dosage of the foaming agent Polyethylene glycol (PEG 600) at 50 and 100 g t⁻¹, collector types Aerophine 3418A (AERO), Danafloat 067 (DF), and potassium ethyl xanthate (KEX) at 50 and 80 g t⁻¹, and a suspension density of 300 and 500 g L⁻¹ on froth flotation collective concentrates were investigated. The final collective concentrate achieved recoveries exceeding 91% for lead (Pb), 88% for copper (Cu), and 87% for zinc (Zn). The obtained concentrates were analyzed using Atomic Absorption Spectroscopy (AAS) and X-ray Fluorescence Spectrometry (XRF), while selected samples were further examined via Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS). The resulting sulfide concentrates can subsequently be treated using suitable hydrometallurgical techniques. The application of these concentrates in metal production would help reduce the environmental burden of mining activities. Full article

Afforestation with Pinus sylvestris var. mongolica in northern China is hindered by soil degradation. This study evaluated a ternary amendment combining sewage sludge (SS), cattle manure (CM), and maize straw (MS) to rehabilitate degraded sandy soils in the Horqin Sandy Land. Five treatments were tested: control (CK), SS (T1), SS + CM (T2), SS+MS (T3), and SS + CM + MS (T4). The ternary amendment (T4) achieved optimal outcomes: soil pH decreased from 8.02 to 7.79, organic carbon increased 2.5–fold, and total nitrogen (127%) and phosphorus (87.5%) were enhanced compared to CK. Pinus sylvestris exhibited a 65.6% greater basal diameter and 29.5% height increase under T4, while heavy metal concentrations (Cd: −54.6%, Cu: −35.1%, Pb: −12.2% and Zn: −27.6%) were reduced. These findings highlight a synergistic waste valorization strategy for dryland afforestation, balancing soil fertility improvement with ecological safety. Future studies should prioritize long-term microbial community dynamics and field-scale validation. Full article

Background: Exploring new strategies to improve type 2 diabetes mellitus (T2DM) is one of the frontier hotspots in the field of healthy food. Flavonoid–metal complexes have become one of the research hotspots in the field of health foods due to their unique structural and functional properties. Methods: In this study, the effect of hesperetin–copper(II) complex [Hsp–Cu(II)] on the gut microbiota of mice with T2DM was investigated by the 16S rRNA high-throughput sequencing. Results: The analyses of α and β diversity indicated that the richness and diversity of gut microbiota in the T2DM mice decreased and the community structure was significantly different from the normal mice. Hsp–Cu(II) increased the abundances of the beneficial bacteria (Lactobacillus, Ligilactobacillus, Romboutsia, Faecalibaculum, and Dubosiella), and decreased the amounts of the harmful bacteria (Desulfobacterota, Corynebacterium, and Desulfovibrio) and the ratio of Firmicutes/Bacteroidetes (from 44.5 to 5.8) in the T2DM mice, which was beneficial for regulating the composition of intestinal microbiota. The linear discriminant analysis effect size analysis showed that the intervention of Hsp–Cu(II) made the short-chain fatty acid (SCFA) producers (o_Lachnospirales, f_Lachnospiraceae, g_Faecalibaculum, g_Romboutsia, and g_Turicibacter) and the lactic acid bacteria producers (f_Lactobacillaceae and o_Lactobacillales) highly enriched, and the production of its metabolite SCFAs (acetic acid, propionic acid, butyric acid, and valeric acid) were increased in a dose-dependent manner, promoting the SCFA metabolism. Conclusions: Hsp–Cu(II) may improve glucose metabolic disorders and alleviate T2DM by modulating gut microbiota composition, promoting probiotics proliferation and SCFAs production, restoring intestinal barrier integrity, and suppressing local inflammation. These research findings may provide a theoretical basis for developing Hsp–Cu(II) as a new hypoglycemic nutritional supplement, and offer new ideas for the dietary food nutritional regulation to alleviate T2DM. Full article

The new mineral achyrophanite (K,Na)₃(Fe³⁺,Ti,Al,Mg)₅O₂(AsO₄)₅ was found in high-temperature sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with aphthitalite-group sulfates, hematite, alluaudite-group arsenates (badalovite, calciojohillerite, johillerite, nickenichite, hatertite, and khrenovite), ozerovaite, pansnerite, arsenatrotitanite, yurmarinite, svabite, tilasite, katiarsite, yurgensonite, As-bearing sanidine, anhydrite, rutile, cassiterite, and pseudobrookite. Achyrophanite occurs as long-prismatic to acicular or, rarer, tabular crystals up to 0.02 × 0.2 × 1.5 mm, which form parallel, radiating, bush-like, or chaotic aggregates up to 3 mm across. It is transparent, straw-yellow to golden yellow, with strong vitreous luster. The mineral is brittle, with (001) perfect cleavage. D_calc is 3.814 g cm^–3. Achyrophanite is optically biaxial (+), α = 1.823(7), β = 1.840(7), γ = 1.895(7) (589 nm), 2V (meas.) = 60(10)°. Chemical composition (wt.%, electron microprobe) is: Na₂O 3.68, K₂O 9.32, CaO 0.38, MgO 1.37, MnO 0.08, CuO 0.82, ZnO 0.48, Al₂O₃ 2.09, Fe₂O₃ 20.42, SiO₂ 0.12, TiO₂ 7.35, P₂O₅ 0.14, V₂O₅ 0.33, As₂O₅ 51.88, SO₃ 1.04, and total 99.40. The empirical formula calculated based on 22 O apfu is Na_1.29K_2.15Ca_0.07Mg_0.34Mn_0.01Cu_0.11Zn_0.06Al_0.44Fe³⁺_2.77Ti_1.00Si_0.02P_0.02S_0.14V_0.04As_4.90O₂₂. Achyrophanite is orthorhombic, space group P222₁, a = 6.5824(2), b = 13.2488(4), c = 10.7613(3) Å, V = 938.48(5) ų and Z = 2. The strongest reflections of the PXRD pattern [d,Å(I)(hkl)] are 5.615(59)(101), 4.174(42)(022), 3.669(31)(130), 3.148(33)(103), 2.852(43)(141), 2.814(100)(042, 202), 2.689(29)(004), and 2.237(28)(152). The crystal structure of achyrophanite (solved from single-crystal XRD data, R = 4.47%) is unique. It is based on the octahedral-tetrahedral M-T-O pseudo-framework (M = Fe³⁺ with admixed Ti, Al, Mg, Na; T = As⁵⁺). Large-cation A sites (A = K, Na) are located in the channels of the pseudo-framework. The achyrophanite structure can be described as stuffed, with the defect heteropolyhedral pseudo-framework derivative of the orthorhombic Fe³⁺AsO₄ archetype. The mineral is named from the Greek άχυρον, straw, and φαίνομαι, to appear, in allusion to its typical straw-yellow color and long prismatic habit of crystals. Full article

The aim of this study was to evaluate the efficacy of manual therapy based on neurodynamic techniques and electrophysical modalities in the conservative treatment of cubital tunnel syndrome (CuTS). A total of 128 upper limbs affected by CuTS were initially enrolled in this study, with 82 completing the full treatment protocol. The participants were divided into the following two intervention arms: the first arm (MT) (42 arms) received therapy based on sliding and tensioning neurodynamic techniques, while the second arm (EM) (40 arms) underwent physiotherapy based on electrophysical modalities, specifically low-level laser therapy (LLLT) and ultrasound therapy (US). Chi² and Student’s t-test were used to compare the intervention arms, and no statistically significant differences were found. The evaluated outcomes included nerve conduction testing, ultrasound assessments (measuring cross-sectional area and shear modulus), pain levels, two-point discrimination, thresholds for cutaneous sensory perception, symptom severity, functional ability in specific tasks, and overall post-treatment improvement. Baseline comparisons indicated no statistically significant differences in any measured variables between the intervention groups (p > 0.05). Following treatment, each group exhibited significant improvements in their respective parameters (p < 0.01). Comparisons between groups post-intervention revealed statistically significant differences in nerve conduction results, ultrasound measurements (cross-sectional area and shear modulus), two-point discrimination, and sensory perception thresholds. These parameters improved more in the MT intervention arm. The use of neurodynamic techniques, ultrasound, and low-level laser therapy in the conservative treatment of mild to moderate forms of CuTS has a beneficial therapeutic effect. Full article