Search Results (103)

An aqueous leaf extract of Egeria densa was used to green-synthesize iron (II) and iron (III) oxide nanoparticles from ferrous sulphate and ferric chloride, respectively. The successful green synthesis of the nanoparticles was confirmed through UV–visible spectroscopy, and the colour of the mixtures changed from light-yellow to green-black and reddish-brown for FeO–NPs and Fe₂O₃–NPs, respectively. The morphological characteristics of the nanoparticles were determined using an X-ray diffractometer (XRD), a Fourier transform infrared spectrophotometer (FTIR), a transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDX). The UV–Vis spectrum of the FeO–NPs showed a sharp peak at 290 nm due to the surface plasmon resonance, while that of the Fe₂O₃–NPs showed a sharp peak at 300 nm. TEM analysis revealed that the FeO–NPs were oval to hexagonal in shape and were clustered together with an average size of 18.49 nm, while the Fe₂O₃-NPs were also oval to hexagonal in shape, but some were irregularly shaped, and they clustered together with an average size of 27.96 nm. EDX analysis showed the presence of elemental iron and oxygen in both types of nanoparticles, indicating that these nanoparticles were essentially present in oxide form. The XRD patterns of both the FeO–NPs and Fe₂O₃–NPs depicted that the nanoparticles produced were crystalline in nature and exhibited the rhombohedral crystal structure of hematite. The FT-IR spectra revealed that phenolic compounds were present on the surface of the nanoparticles and were responsible for reducing the iron salts into FeO–NPs and Fe₂O₃–NPs. Conclusively, this work demonstrated for the first time the ability of Elodea aqueous extract to synthesize iron-based nanoparticles from both iron (II) and iron (III) salts, highlighting its versatility as a green reducing and stabilizing agent. The dual-path synthesis approach provides new insights into the influence of the precursor oxidation state on nanoparticle formation, thereby expanding our understanding of plant-mediated nanoparticle production and offering a sustainable route for the fabrication of diverse iron oxide nanostructures. Furthermore, it provides a simple, cost-effective, and environmentally friendly method for the synthesis of the FeO–NPs and Fe₂O₃–NPs using Egeria densa. Full article

The recycling of lithium iron phosphate (LiFePO₄) batteries from electric and hybrid vehicles was investigated, by applying mechanical pretreatment and hydrometallurgical methods. The aim was to extract lithium (Li) into the aqueous solution and precipitate iron (Fe) in the form of ferric iron phosphate (FePO₄). Samples of lithium iron phosphate (LFP) batteries from small electric vehicles provided by the company BEEV were used in this study. Initially, the black mass was isolated using mechanical crushing, screening, and sink–float separation methods, avoiding the need for costly chemical or thermal treatments. The cathodic material was then leached with sulfuric acid (H₂SO₄) and hydrogen peroxide (H₂O₂) to oxidize ferrous to ferric iron, resulting in the precipitation of iron phosphate, which was collected in the solid residue from the leaching process. Leaching tests were conducted by varying the concentrations of sulfuric acid and hydrogen peroxide, as well as the leaching time. It has been indicated that by using a sulfuric acid concentration equal to the stoichiometric requirement, and hydrogen peroxide at four times the stoichiometric amount, Li extraction of greater than 98% was achieved within the first few minutes of leaching, while iron extraction remained below 0.5%. Full article

Iron is an essential micronutrient required for the fungal growth and propagation. Fusarium proliferatum is the causal agent of rice spikelet rot disease. In this study, we characterized the role of F. proliferatum multicopper ferroxidase (FpfetC), which mediated the oxidization of ferrous to ferric iron in the reductive system of iron assimilation. Deletion of FpfetC led to impaired growth under iron-deprived conditions, and the growth defect could be restored by exogenous iron. Compared to wild-type Fp9 strain, ΔFpfetC showed increased conidiation, resistance to copper stress, and sensitivity to zinc stress. FpfetC deficiency rendered a transcription remodeling of genes involved in high-affinity iron assimilation, iron homeostasis and iron storage. Moreover, production of fumonisin B1 (FB1) and transcript levels of fumonisin biosynthesis (Fpfums) genes were elevated in ΔFpfetC. ΔFpfetC exhibited hypervirulence to rice, accompanied with aggravation of invasive hyphae and activation of siderophore synthesis at the sites of inoculation. Additionally, disruption of FpfetC attenuated penetration ability to cellophane membrane under iron starvation. Taken together, these results demonstrated that FpfetC played important roles in iron uptake, conidiation, response to metal stress, fumonisin biosynthesis, and virulence in F. proliferatum. Full article

Carthamus caeruleus L. is traditionally used in Algerian medicine, particularly for burn treatment, but its therapeutic potential remains insufficiently studied. This study aimed to evaluate the antioxidant and anti-inflammatory properties of the root aqueous extract, and to perform phytochemical characterization to identify its bioactive compounds. Phytochemical analysis was conducted using spectrophotometry and reverse-phase high-performance liquid chromatography (RP-HPLC). The antioxidant potential was assessed through various assays, including ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), DPPH radical scavenging, hydroxyl radical scavenging, ferrous ion chelation, and hydrogen peroxide decomposition. Anti-inflammatory activity was evaluated using membrane stabilization, protein denaturation, and membrane peroxidation assays. The extract exhibited moderate levels of polyphenols, flavonoids, and condensed tannins, quantified as 21.19 ± 0.37 mg GAE/g, 0.72 ± 0.013 mg QE/g, and 27.28 ± 1.04 mg TAE/g of dry extract, respectively. RP-HPLC analysis identified 22 phytochemical compounds, primarily phenolic acids, flavonoids, and tannins, with orientin and vanillin as the major constituents. The extract demonstrated significant antioxidant activity, with moderate efficacy in TAC and FRAP assays (IC₅₀ values of 5405.1 ± 4.42 and 1132.35 ± 4.97 µg/mL, respectively). Notable activities included DPPH and hydroxyl radical scavenging (34.43 ± 4.83 and 512.81 ± 9.46 µg/mL, respectively), ferrous ion chelation (2462.76 ± 1.38 µg/mL), lipid peroxidation inhibition (22.32 ± 3.31%), and hydrogen peroxide decomposition (263.93 ± 7.87 µg/mL). Additionally, the extract stabilized erythrocyte membranes under osmotic, thermal, and oxidative stress conditions (98.13 ± 0.15%, 70 ± 1.27%, and 89 ± 0.87%, respectively), inhibited ovalbumin denaturation (81.05 ± 2.2%), and protected against lipid peroxidation in brain homogenates (69.25 ± 0.89%). These findings support the traditional therapeutic applications of C. caeruleus and highlight its potential as a source of antioxidant and anti-inflammatory agents. Full article

The growing demand for eco-friendly activated carbon necessitates sustainable production methods. This study investigates the conversion of waste wood into activated carbon using goethite iron ore as an activating agent. A high-temperature rotary furnace was used to activate the carbon at 1373 K. The oxygen released from the iron oxide during the heat treatment reacted with the carbon in the wood, resulting in 49% of activated carbon with BET surface areas between 684 m²/g and 770 m²/g. The activated carbon and char showed type I isotherms with micropore areas between 600 m²/g and 668 m²/g, respectively. Additionally, 92% of the iron in the ore was reduced from ferric to ferrous. The findings demonstrate that goethite iron ore is an effective activating agent for producing wood-based activated carbon while also generating metallic iron as a byproduct. This alternative activation method enhances the sustainability and efficiency of activated carbon production. Full article

Iron, Earth’s most abundant redox-active metal, undergoes both abiotic and microbial redox reactions that regulate the formation, transformation, and dissolution of iron minerals. The electron transfer between ferrous iron (Fe(II)) and ferric iron (Fe(III)) is critical for mineral dynamics, pollutant remediation, and global biogeochemical cycling. Bacteria play a significant role, especially in anaerobic Fe(II) oxidation, contributing to Fe(III) mineral formation in oxygen-depleted environments. In iron-rich, neutral anaerobic settings, microbial nitrate-reducing Fe(II) oxidation (NRFO) and iron reduction processes happen simultaneously. This study used Shewanella oneidensis MR-1 to create an anaerobic NRFO system between Fe(II) and nitrate, revealing concurrent Fe(II) oxidation and nitrate reduction. Both gene-mediated biological Fe(II) oxidation and chemical Fe(II) oxidation, facilitated by nitrite (a byproduct of nitrate reduction), were observed. The MtrABC gene cluster was linked to this process. At low Fe(II) concentrations, toxicity and mineral precipitation inhibited nitrate reduction by Shewanella oneidensis MR-1, whereas high Fe(II) levels led to Fe(II) oxidation, resulting in cell encrustation, which further constrained nitrate reduction. Full article

Light element alloying in iron is required to explain density deficit and seismic wave velocities in Earth’s core. However, the light element composition of the Earth’s core seems hard to constrain as nearly all light element alloying would reduce the density and sound velocity (elastic moduli). The alloying light elements include oxidizing elements like oxygen and sulfur and reducing elements like hydrogen and carbon, yet their chemical effects in the alloy system are less discussed. Moreover, Fe-X-ray Absorption Near Edge Structure (Fe-XANES) fingerprints have been studied for silicate materials with ferrous and ferric ions, while not many X-ray absorption spectroscopy (XAS) studies have focused on iron alloys, especially at high pressures. To investigate the bonding nature of iron alloys in planetary interiors, we presented X-ray absorption spectroscopy of iron–nitrogen and iron–carbon alloys at high pressures up to 50 GPa. Together with existing literature on iron–carbon, –hydrogen alloys, we analyzed their edge positions and found no significant difference in the degree of oxidation among these alloys. Pressure effects on edge positions were also found negligible. Our theoretical simulation of the valence state of iron, alloyed with S, C, O, N, and P also showed nearly unchanged behavior under pressures up to 300 GPa. This finding indicates that the high pressure bonding of iron alloyed with light elements closely resembles bonding at the ambient conditions. We suggest that the chemical properties of light elements constrain which ones can coexist within iron alloys. Full article

Persulfates (PSs) have recently gained recognition as strong oxidants notably for soil and groundwater remediation. Ferrous iron (Fe(II)) has been extensively employed in activating PS. However, the PS/Fe(II) system still suffers from some inherent drawbacks, including the fast accumulation of ferric ion (Fe(III)) or precipitation of Fe(III), sluggish conversion from Fe(III) to Fe(II), and the unwanted scavenging of SO₄^•− by excess Fe(II). To overcome these issues, the following two types of reagents are usually used: chelating agents and reducing agents. There are 11 chelating agents mentioned in this paper (EDTA, CA, etc.) and 3 reducing agents (HA, thiosulfate and A-Boron). This review extracted data from studies to give a data-based overview on how the added agents can improve the PS/Fe(II) system under varied conditions. The mechanisms of improvement by chelating agents could be classified into the following three categories: to control excess Fe(II), reduce Fe(III) to Fe(II), and inhibit Fe precipitation. The data analysis suggested an optimal working agent/Fe(II) ratio of 0–2 with acidic and neutral pH. The mechanism of using a reducing agent for PS/Fe(II) system improvement is simply reducing Fe(III) to Fe(II), using hydroxylamine, thiosulfate, etc. The improvement was significant at a hydroxylamine/Fe (II) molar ratio between 0 and 10, yet overdosed hydroxylamine can scavenge the reactive radicals, resulting in negative effects. The future research trend was also proposed in this review. Full article

This study conducts a comparative analysis of cystamine (RSSR), a disulfide, and cysteamine (RSH), its thiol monomer, to evaluate their efficacy as radioprotectors and antioxidants under high linear energy transfer (LET) and high-dose-rate irradiation conditions. It examines their interactions with reactive primary species produced during the radiolysis of the aqueous ferrous sulfate (Fricke) dosimeter, offering insights into the mechanisms of radioprotection and highlighting their potential to enhance the therapeutic index of radiation therapy, particularly in advanced techniques like FLASH radiotherapy. Using Monte Carlo multi-track chemical modeling to simulate the radiolytic oxidation of ferrous to ferric ions in Fricke-cystamine and Fricke-cysteamine solutions, this study assesses the radioprotective and antioxidant properties of these compounds across a variety of irradiation conditions. Concentrations were varied in both aerated (oxygen-rich) and deaerated (hypoxic) environments, simulating conditions akin to healthy tissue and tumors. Both cystamine and cysteamine demonstrate radioprotective and strong antioxidant properties. However, their effectiveness varies significantly depending on the concentration employed, the conditions of irradiation, and whether or not environmental oxygen is present. Specifically, excluding potential in vivo toxicity, cysteamine substantially reduces the adverse effects of ionizing radiation under aerated, low-LET conditions at concentrations above ~1 mM. However, its efficacy is minimal in hypoxic environments, irrespective of the concentration used. Conversely, cystamine consistently offers robust protective effects in both oxygen-rich and oxygen-poor conditions. The distinct protective capacities of cysteamine and cystamine underscore cysteamine’s enhanced potential in radiotherapeutic settings aimed at safeguarding healthy tissues from radiation-induced damage while effectively targeting tumor tissues. This differential effectiveness emphasizes the need for personalized radioprotective strategies, tailored to the specific environmental conditions of the tissue involved. Implementing such approaches is crucial for optimizing therapeutic outcomes and minimizing collateral damage in cancer treatment. Full article

Due to energy shortages and the greenhouse effect, the efficient use of energy through phase-change materials (PCMs) is gaining increased attention. In this study, magnetic phase-change microcapsules (Mag-mc) were prepared by suspension polymerization. The shell layer of the microcapsules was formed by copolymerizing methyl methacrylate and triethoxyethylene silane, with the latter enhancing the compatibility of the shell layer with the magnetic additive. Ferric ferrous oxide modified by oleic acid (Fe₃O₄(_m)) was added as the magnetic additive. Differential scanning calorimetry (DSC) testing revealed that the content of phase-change materials in microcapsules without and with ferric ferrous oxide were 79.77% and 96.63%, respectively, demonstrating that the addition of Fe₃O₄(_m) improved the encapsulation efficiency and enhanced the energy storage ability of the microcapsules. Laser particle size analysis showed that the overall average particle sizes for the microcapsules without and with ferric ferrous oxide were 3.48 μm and 2.09 μm, respectively, indicating that the incorporation of magnetic materials reduced the size and distribution of the microcapsules. Thermogravimetric analysis indicated that the thermal stability of the microcapsules was enhanced by the addition of Fe₃O₄(_m). Moreover, the infrared emissivity of the microcapsule-containing film decreased from 0.77 to 0.72 with the addition of Fe₃O₄(_m) to the shell of microcapsules. Full article

In this work an innovative approach was developed to address a significant challenge in the field of radiation dosimetry: the accurate measurement of spatial dose distributions using Fricke gel dosimeters. Hydrogels are widely used in radiation dosimetry due to their ability to simulate the tissue-equivalent properties of human tissue, making them ideal for measuring and mapping radiation dose distributions. Among the various gel dosimeters, Fricke gels exploit the radiation-induced oxidation of ferrous ions to ferric ions and are particularly notable due to their sensitivity. The concentration of ferric ions can be measured using various techniques, including magnetic resonance imaging (MRI) or spectrophotometry. While Fricke gels offer several advantages, a significant hurdle to their widespread application is the diffusion of ferric ions within the gel matrix. This phenomenon leads to a blurring of the dose distribution over time, compromising the accuracy of dose measurements. To mitigate the issue of ferric ion diffusion, researchers have explored various strategies such as the incorporation of additives or modification of the gel composition to either reduce the mobility of ferric ions or stabilize the gel matrix. The computational method proposed leverages the power of artificial intelligence, particularly deep learning, to mitigate the effects of ferric ion diffusion that can compromise measurement precision. By employing Physics Informed Neural Networks (PINNs), the method introduces a novel way to apply physical laws directly within the learning process, optimizing the network to adhere to the principles governing ion diffusion. This is particularly advantageous for solving the partial differential equations that describe the diffusion process in 2D and 3D. By inputting the spatial distribution of ferric ions at a given time, along with boundary conditions and the diffusion coefficient, the model can backtrack to accurately reconstruct the original ion distribution. This capability is crucial for enhancing the fidelity of 3D spatial dose measurements, ensuring that the data reflect the true dose distribution without the artifacts introduced by ion migration. Here, multidimensional models able to handle 2D and 3D data were developed and tested against dose distributions numerically evolved in time from 20 to 100 h. The results in terms of various metrics show a significant agreement in both 2D and 3D dose distributions. In particular, the mean square error of the prediction spans the range $1\times {10}^{-6}$–$1\times {10}^{-4}$, while the gamma analysis results in a 90–100% passing rate with 3%/2 mm, depending on the elapsed time, the type of distribution modeled and the dimensionality. This method could expand the applicability of Fricke gel dosimeters to a wider range of measurement tasks, from simple planar dose assessments to intricate volumetric analyses. The proposed technique holds great promise for overcoming the limitations imposed by ion diffusion in Fricke gel dosimeters. Full article

In the small intestine, nutrients from ingested food are absorbed and broken down by enterocytes, which constitute over 95% of the intestinal epithelium. Enterocytes demonstrate diet- and segment-dependent metabolic flexibility, enabling them to take up large amounts of glutamine and glucose to meet their energy needs and transfer these nutrients into the bloodstream. During glycolysis, ATP, lactate, and H⁺ ions are produced within the enterocytes. Based on extensive but incomplete glutamine oxidation large amounts of alanine or lactate are produced. Lactate, in turn, promotes hypoxia-inducible factor-1α (Hif-1α) activation and Hif-1α-dependent transcription of various proton channels and exchangers, which extrude cytoplasmic H⁺-ions into the intestinal lumen. In parallel, the vitamin C-dependent and duodenal cytochrome b-mediated conversion of ferric iron into ferrous iron progresses. Finally, the generated electrochemical gradient is utilized by the divalent metal transporter 1 for H⁺-coupled uptake of non-heme Fe²⁺-ions. Iron efflux from enterocytes, subsequent binding to the plasma protein transferrin, and systemic distribution supply a wide range of cells with iron, including erythroid precursors essential for erythropoiesis. In this review, we discuss the impact of vitamin C on the redox capacity of human erythrocytes and connect enterocyte function with iron metabolism, highlighting its effects on erythropoiesis. Full article

Microwave-based reactions have gained traction in recent years due to their ability to enhance reaction rates and yield while reducing energy consumption. Also, according to the conception of ‘waste to materials’, various waste feeds are intensively sought to be tested. The experimental setup of this study involved varying pH levels, oxidation agents, and precipitation agents to optimize the synthesis process of iron red based on waste iron sulfate. The selection of oxidation and precipitation agents was found to significantly influence the pigment synthesis process. Various oxidizing agents, including hydrogen peroxide and atmospheric air, were evaluated for their effectiveness in promoting the oxidation of ferrous ions to ferric ions, essential for pigment formation. Additionally, different precipitation agents such as sodium hydroxide and ammonia solution were assessed for their ability to precipitate iron hydroxides and facilitate pigment particle formation. The characterization of synthesized pigments revealed promising results in terms of quality and color properties. Helium Ion Microscopy (HIM) analysis confirmed the formation of well-defined pigment particles with controlled morphology. X-ray diffraction (XRD) studies provided insights into the crystalline structure of the pigments, indicating the presence of characteristic iron oxide phases. By improving this technology, waste iron sulfate can be efficiently transformed into valuable iron pigments, offering a sustainable solution for waste management while meeting the growing demand for high-quality pigments. Full article

The chemical composition of extracts (CEs) and essential oils (EOs) from Tetradenia riparia leaves, flower buds, and stems was analyzed. Antiproliferative activity against tumor cell lines, NO production inhibition, and antioxidant and antiviral activities were assessed. The CEs contained flavonoids, phenolic acids, coumarins, and saturated fatty acids. The EOs included monoterpenes, oxygenated sesquiterpenes, and diterpenes. NO production inhibition ranged from 76 to 247 µg mL⁻¹, and antiproliferative activity exhibited GI₅₀ between 20 and >204 µg mL⁻¹, with low cytotoxicity (SI: 1.08 to 4.75). Reactive oxygen species inhibition ranged from 45 to 82%. Antioxidant activity varied when determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (IC₅₀: 0.51 to 8.47 mg mL⁻¹) and ferric reducing antioxidant power (0.35 to 0.81 µM ferrous sulfate per mg). The reduction in β-carotene–linoleic acid co-oxidation varied between 76.13 and 102.25%. The total phenolic content of CEs and EOs was 10.70 to 111.68 µg gallic acid mg⁻¹. Antiviral activity against herpes simplex virus type 1 (HSV-1) showed an EC₅₀ between 9.64 and 24.55 µg mL⁻¹ and an SI between 8.67 and 15.04. Leaf EOs exhibited an EC₅₀ of 9.64 µg mL⁻¹ and an SI of 15.04. Our study unveils the diverse chemical composition and multifaceted pharmacological properties of T. riparia, demonstrating its potential as a valuable source of bioactive compounds for therapeutic applications. Full article

Textile industry effluents contain several hazardous substances, such as dye-containing effluents, which pose environmental and aesthetic challenges. Presently, the microbial-based remediation process is in use. This study investigated the application of ferrous–ferric oxide (Fe₃O₄) nanoparticles, a readily formulated nanoadsorbent, to remove scattered dye molecules from industrial effluents. The ferrous–ferric oxide nanoparticles were prepared using a chemical co-precipitation method. The nanoparticles had 26.93 emu g⁻¹ magnetization, with sizes smaller than 20 nm, and possessed a highly purified cubic spinel crystallite structure. The catalytic activity of the iron oxide depended on the dose, photocatalytic enhancer, i.e., H₂O₂ level, pH of the reaction medium, and dye concentration. We optimized the Fenton-like reaction to work best using 1.0 g/L of ferrous–ferric oxide nanoparticles, 60 mM oxalic acid at pH 7.0, and 60 ppm of dye. Iron oxides act as photocatalysts, and oxalic acid generates electron–hole pairs. Consequently, higher amounts of super-radicals cause the rapid degradation of dye and pseudo-first-order reactions. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed the ferrous–ferric oxide nanoparticles decolorized and destroyed Disperse Red 277 in 180 min under visible light. Hence, complete demineralization is observed using a photo-Fenton-like reaction within 3 h under visible light. These high-capacity, easy-to-separate next-generation adsorption systems are suggested to be suitable for industrial-scale use. Ferrous–ferric oxide nanoparticles with increased adsorption and magnetic properties could be utilized to clean environmental pollution. Full article