Concentration Of Iron Ions Research Articles

Use of humate-sapropelic suspension when growing sunn hemp (Crotalaria junceae L.) in protected soil conditions (greenhouse)

Among the species of the genus Crotalaria L., Crotalaria juncea is the only cover crop cultivated for its fiber. The quality of the latter depends on nutritional conditions, the accumulation of biophilic elements in the biomass and the synthesis of proteinogenic amino acids. Thus, the purpose of the study was a qualitative and quantitative assessment of the green harvest at the stage of active flowering, before the phase of bean formation, when the entire biochemical cycle of the plant is reconfigured, and biochemical indicators are maximum. The plants were grown for 140 days (from April 22 to September 9, 2023) in protected soil conditions. The experimental design consisted of two blocks of 50 plants: in the first (control) plants were grown in a soil mixture without any additives; in the second, the crop was treated three times during the growing season with an organic suspension of humic acids (1000 ppm) obtained from sapropel (Pskov region) – UDGSS, by applying it when watering at the root. The soil substrate in both cases was typical chernozem (Kamennaya Steppe nature reserve, Voronezh region, 51°01ʹ41.6ʹʹN 40°43ʹ39.3ʹʹE) with a 20% addition of volcanic zeolite. Over the course of every 14 days, a systematic record of the dynamics of changes in the morphometric indicators of crop growth (height and dry biomass) was carried out, by removing five cultivars from each block of variants. After 140 days, the remaining five replicates per variant were subjected to biochemical analysis using inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC) using 7500 and LC 1200 instruments (Agilent Technologies, USA), according to the manufacturer's method. Treatment with UDGSS increased productivity and shoot height by 51.1% and 11.3%, respectively. The concentration of macroelements in dry biomass was in the following order: NaKCaSPMg in the control and NaKCaMgPS in the variant with UDGSS, and the export of microelements – FeMnZn BaBCuMo and FeMnBZnBaCuMo. At the same time, in total, the increase was more manifested in the amount of accumulation of microelements, due to a twofold increase in the concentration of iron ions. Among amino acids, an increase in the concentration of L-Lysine, L-Glycine, L-Glutamine and L-tyrosine was observed. The first three are structural components of biological tissues, which indirectly indicates an increase in the fiber strength of the culture.

Kinetics and Reusability of Hydrophobic Eutectic Solvents in Continuous Extraction Processes in a Pilot Setting

Hydrophobic eutectic solvents (HES) show significant promise as extractants for metal ions. At their current stage of development, however, they have many disadvantages, such as high costs, limited data on reusability and, often, lower extraction efficiency when compared with traditional extraction systems. This study investigates the physico-chemical properties of five HES formulations based on 1-octanol in combination with camphor, 2′-hydroxypropiophenone, menthol, 1-octanoic acid, and thymol. The 1-octanol/camphor HES exhibited substantially higher extraction efficiency for Fe(III) ions than a solution of 1-octanol in toluene at the same concentration. Furthermore, it showed stability when used in a mixer-settler type extractor. The 1-octanol/camphor HES achieved a rapid extraction and re-extraction rate, with phase contact time reduced to just 2 min, without loss of extraction efficiency. Using the supported liquid membrane method, the proposed Oct/Cam HES enabled a threefold concentration of iron ions in the raffinate phase under continuous operation, confirming its potential for reusability.

A simulated sunlight-activated plastic mimic enzyme for dual-mode detection of D-penicillamine and serum iron

No reports disclosed that whether the plastic centrifuge tube with intrinsic photoenzyme activity can be used for the specific sensing of pharmaceuticals and biomarkers in biofluids so far. We herein report the plastic eppendorf (EP) tube as both reaction vessel and sunlight-activated plastic mimic enzyme for colorimetric/smartphone dual-mode detection of D-penicillamine (D-PA) and iron (Ⅲ) ions in goat and rabbit serums accordingly. The photooxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) combined with simulated sunlight-activated EP tube was selectively inhibited by adding D-PA, and the absorbance at 652 nm of oxidized TMB decreased. Good linearity between the absorbance variation (or R/(R + G + B)) and D-PA level ranging from 10 to 300 µM was obtained, and the limits of detection (LOD) were determined as 8.50 μM (colorimetric) and 6.92μM (smartphone). Furthermore, the polyvinyl alcohol hydrogel encapsulated TMB in EP tube as a smartphone biosensor had been triumphantly used to monitor D-PA level in goat serum. Interestingly, the adsorption band of photo-oxidized EP tube-TMB system inhibited by D-PA gradually increased as the enhancement of iron (Ⅲ) ions concentration. Based on the “on–off-on” effect, a sensitive and selective method was further used for selectively sensing iron (Ⅲ) in rabbit serum. Notably, the dual-mode sensing platforms exhibited outstanding detection performance, with LOD values as low as 0.50 µM and 0.65 µM respectively. In short, this work not only excavated a photoactivated-plastic mimics, but also developed a robust, low-cost, simple and sensitive biosensor for simultaneous detection of D-PA and Fe (Ⅲ) ions in biofluids. The current photoactivated sensor does not requires the introduction of exogenous catalyst except for simulated sunlight, plastic tube and chromogenic substrate.

Glyphosate and glyphosate-based herbicides induce Poecilia reticulata to maintain redox equilibrium during and after coexposure to iron oxide nanoparticles (y-Fe2O3)

Iron oxide nanoparticles (IONPs) are being increasingly recognized as viable materials for environmental remediation due to their capacity to adsorb contaminants such as glyphosate (GLY) on their surfaces. Nevertheless, the ecotoxicological implications of IONPs associated with GLY necessitate thorough evaluation to ascertain the safety of such remediation strategies. In this context, the present investigation was conducted to examine hepatic biomarkers pertinent to the redox system, as well as ultrastructural hepatic alterations in Poecilia reticulata, following a 21-day exposure to environmentally relevant concentrations of IONPs, iron ions (Fe), and glyphosate in its pure form (GLY) as well as a commercial glyphosate-based herbicide (GBH). After this exposure, the fish underwent a 21-day recovery in uncontaminated water. The results indicated an increase in the activity of catalase (CAT) and glutathione S-transferase (GST) and in the concentration of glutathione (GSH) in the animals subjected to IONP+GBH and IONP+GLY treatments. This biochemical response persisted for the duration of both the exposure and recovery phases. Concurrently, hepatocytes displayed mitochondria with increased electron density, augmented lipid droplet accumulation, and expanded necrotic areas within the hepatic tissue. In contrast, fish exposed solely to IONPs exhibited sustained redox homeostasis throughout the investigative timeline. These findings suggest that the coexposure toxicity of IONP+GLY and IONP+GBH is attributable to the agent adsorbed onto the IONPs and that P. reticulata could maintain an active antioxidant defense mechanism throughout the entire study period.

Rhodamine B‐Modified Nanocrystalline Cellulose as Fluorescent Sensor for Fe3+ Ion Detection

AbstractIron is crucial for various biological processes in humans, animals, and plants, making precise and efficient monitoring of iron ion concentrations essential. To address this need, a cellulose‐based smart fluorescent material (NCC@NH2@RB) with a conjugated structure is designed and synthesized for the rapid and sensitive detection of Fe3+ ions. This sensor features core‐shell nanoparticles functionalized with rhodamine B (RB), using (3‐aminopropyl)triethoxysilane (APTES) as a linker. The resulting fluorescent probe, composed of nanocrystalline cellulose and RB, exhibits strong fluorescence under ultraviolet light, making it an effective tool for Fe3+ ion detection in water. When Fe3+ ions are introduced into a solution containing NCC@NH2@RB, they bind with weak‐field ligands such as nitrogen and oxygen in the probe's structure, forming complexes. This interaction involves high‐spin coordination and leads to the self‐assembly of Fe3+ ions on the surface of NCC@NH2@RB. The process generates single electrons, increasing paramagnetism and quenching the fluorescence. The NCC@NH2@RB fluorescent probe has a limit of detection (LOD) of 0.01 µM and a limit of quantification (LOQ) of 0.03 µM with linearity at concentrations of 1.0 × 10−4–2.5 × 10−3 m. This fluorescence quenching effect is specific to Fe3+ ions, ensuring that the probe remains unaffected by other metal ions.

Biotechnology of groundwater purification for water supply systems, using Gallionella and Lepthothrix ferrobacteria

Aim. The aim of the study was to consider the possibility of using the consortia of chemolithoautotrophic ferrobacteria from Gallionella genus and heterotrophic bacteria from Lepthothrix genus for the biological method of groundwater purification. Methods. The photocolorimetric method to determine the concentrations of ammonium and iron ions, the titrimetric method to determine the hydrocarbon and total alkalinity, the method of determining the permanganate oxidizability using the Kubel method, the potentiometric method to determine the values of рН and Еh, the electronic microscopy using the X-ray spectral analysis of matrix structures of bio-minerals, microbiological and statistical methods. Results. The main technological parameters of the water deironing process were defined as follows: the filtration velocity of the bioreactor – 7–11 m/h, and of the filters – 3.5–5 m/h; the filter-cycle duration – 48 h. It was found that the application of the two-stage technology of biological deironing in the bioreactor and filters provided for the possible removal of Fe2+ compounds up to 5.0 mg/cdm, ammonium nitrogen — up to 1.5 mg/cdm, soluble organic substances by PO – up to 6.0 mg O2/cdm. It was determined that the optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were as follows: рН 7.0–7.2; hydrocarbon alkalinity 2.5–2.2 mmol/cdm; content of soluble oxygen – 1.5–2.0 mg/cdm. The ability of concentrated (Dos 200 mg/cdm) matrix structures of Gallionella and Lepthothrix ferrobacteria to remove Cr6+ ions from natural groundwaters was determined. The study found no considerable differences in the efficiency of applying disinfectants, produced using polyhexamethylene guanidine chloride (PHMGchl) or polyhexamethylene biguanidine chloride (PHMBchl). In concentrations of 0.25–0.5 %, they effectively disinfect pathogenic microorganisms, including Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The same was found true for the bacteria, most common in the systems of technical reverse water supply, the systems of water circulation, plant watering, and fire tanks, including Aeromonas hydrophila, Aeromonas salmonicida, Pseudomonas sp., E. coli, Flavobacterium columnare, Micrococcus lysodeikticus. Conclusions. This was the first study on the possibility of applying the biotechnology of groundwater purification from excessive amounts of iron in conditions of uneven hydraulic burden, notable for the water supply systems of rural areas and most agricultural enterprises in the north-western and northern regions of Ukraine. The specificities and perspectives of PHMGchl application in the systems of water preparation were studied. It was found that from the standpoint of safety and efficiency, the use of the water deironing processes involving iron bacteria was reasonable in the systems of water consumption and technical water supply, and the disinfection of water using PHMG was possible only in the second case, due to some toxicity of the preparation. The optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were determined.

High-throughput point-of-care serum iron testing utilizing machine learning-assisted deep eutectic solvent fluorescence detection platform

In this study, a high-throughput point-of-care testing (HT-POCT) system for detecting serum iron was developed using a hydrophobic deep eutectic solvent (HDES) fluorescence detection platform. This machine learning-assisted portable platform enables intelligent and rapid detection of trace iron ions. Blue fluorescent hydrophobic carbon quantum dots (CQDs) were synthesized using the solvothermal method. The CQDs exhibit a notable quantum yield (QY) of 36.6%, demonstrating exceptional luminescent characteristics and precise, sensitive detection capabilities for Fe3+ ions. By incorporating CQDs into specially filtered HDESs, this blend serves a dual function of concentrating iron ions from the sample and facilitating their detection. The collaboration between the two enhances the fluorescence detection signal significantly, while reducing interference from hydrophilic substances. The limit of detection can be as low as 33 nM. The principles of synthesizing HDESs and the process of extracting Fe3+ using HDESs fluorescence detection system were modeled using density functional theory (DFT). As the concentration of Fe3+ increases, the fluorescence signal detected from the sample decreases, accompanied by visible color changes when exposed to ultraviolet light. The machine learning-assisted portable platform is designed to capture fluorescence images of samples directly. The application developed using the YOLOv8 algorithm efficiently analyzes multiple samples in single or multiple images, simultaneously extracting color data from each sample and determining the concentration of iron ions. The Relative Standard Deviations (RSDs) for both single-sample and multi-sample tests were less than 10%. The machine learning-assisted portable platform provides a reliable method for detecting trace iron ions.

Efficiency of Reverse Osmosis Usage in Drinking Water Depots to Reduce Iron (Fe3+), Copper (Cu2+) and Zinc (Zn2+) Ion Levels

Research on the efficiency of reverse-osmosis drinking water depot to decreased levels of iron (Fe3+), Copper (Cu2+) and Zinc (Zn2+) ions have been done. The raw, the treated, and waste water are filtered using reverse osmosis (RO) three times a week. HNO3 then was added to the sample until it reached 15 mL. The determination of the concentration of the three ions was performed using atomic absorption spectrophotometer (AAS). The results showed a decrease of Fe3+ concentration of 73.21%, for Cu2+ decrease by 80.25%, while Zn2+ decrease by 82.08%. For waste water obtained iron ion concentration of 0.1794 mg/L, for Cu2+ by 0.0239 mg/L, while Zn2+ by 0.0962 mg/L.

The degradation of Sulfamethoxazole using a heterojunction photocatalytic membrane composed of Z-scheme LaFeO3/Ag3PO4@GO: Assessment of activity and degradation mechanisms

We synthesized La-deficient LaFeO3 through a simple hydrothermal method, enhancing the physicochemical properties and catalytic performance of the initial LaFeO3. Subsequently, Ag3PO4 was grown on 0.7 LaFeO3 using electrostatic deposition to obtain composite materials LA-1, LA-2, and LA-3 with different composite ratios, improving the transfer rate of photogenerated charge carriers and reducing impedance. By physically combining LA with GO, a photocatalytic membrane LAG was produced, effectively enhancing the stability and recyclability of the photocatalytic membrane. The photocatalytic membrane LAG-2 achieved an 80.4 % SMX degradation efficiency under neutral conditions, with a degradation rate of 76.5 % at pH=3. The retention rate for SMX was 82 %, with a flux of 106.2 L·m−2 h−1 bar−1. Additionally, the flux for CIP reached 530.8 L·m−2 h−1 bar−1, with a retention rate of 65.5 %. After six cycling experiments, the degradation rate of LAG-2 was 67.4 %, and the leaching concentration of iron ions exhibited good performance. SEM analysis reveals that the morphology of the membrane remains intact before and after the cycle, with LAG retaining its integrity and exhibiting excellent mechanical properties. This indicates that the photocatalytic membrane demonstrates good stability and reusability. The excellent integration of the photocatalyst and membrane overcomes the challenge of difficult recovery of the photocatalyst, promising extensive applications and providing new insights for the practical application of photocatalytic degradation of antibiotics.

Development of oxidative stress- and ferroptosis-related prognostic signature in gastric cancer and identification of CDH19 as a novel biomarker

BackgroundFerroptosis is a unique mode of cell death that is iron-dependent and associated with oxidative stress and lipid peroxidation. Oxidative stress and ferroptosis are essential mechanisms leading to metabolic abnormalities in cells and have been popular areas in cancer research.MethodsInitially, 76 oxidative stress and ferroptosis-related genes (OFRGs) were acquired by intersecting the gene sets from oxidative stress and ferroptosis. Afterwards, optimal OFRGs were screened using PPI networks, and individuals were separated into two OFRG subtypes (K = 2). Subsequently, we successfully constructed and verified a prognostic signature comprising SLC7A2, Cadherin 19 (CDH19), and CCN1. To further uncover potential biomarkers of gastric cancer (GC), we examined the expression level of CDH19, investigated the effects of knocking down CDH19 on the biological behavior of GC cells, and explored whether CDH19 is involved in ferroptosis and oxidative stress processes.ResultsAccording to the findings, individuals in the low-risk scoring group have less infiltration of immune suppressive cells, fewer occurrences of immune escape and dysfunction, greater efficacy in chemotherapy and immunotherapy, and better survival outcomes. The qRT-PCR assay indicated that CDH19 expression was significantly higher in GC cells. Through experiments, we demonstrated that knocking down CDH19 can affect the transcription levels of ACSL4 and GPX4, increase intracellular iron ion concentration and accumulation of reactive oxygen species (ROS), and inhibit the proliferation and migration of GC cells.ConclusionWe developed an OFRG-related signature to predict the prognosis and treatment responsiveness of individuals with GC and identified CDH19 as a possible therapeutic target for GC.

Furfural production from xylan using a Pueraria Residues carbon-based solid-acid catalyst.

The conversion of biomass into high value-added platform compounds is an important method of biomass utilization. The conversion of hemicellulose represented by xylan into furfural can not only reduce the consumption of fossil fuels, but also promotes the development and utilization of non-edible biomass resources. In this study, a bifunctional solid-acid catalyst prepared from agricultural and forestry waste Pueraria (P. eduli) Residues was used to convert xylan into furfural in a biphasic system. In this study, P. eduli Residues was used as raw material to prepare a P. eduli Residues-based carbon solid-acid catalyst (PR/C-SO3H-Fe) by one-step sulfonation carbonization and impregnation. The catalyst catalyzes the conversion of xylan to furfural in a biphasic system (2-methyltetrahydrofuran/water). The physicochemical properties of the catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, differential thermogravimetric analysis, Brunauer-Emmett-Teller surface area, Fourier transform infrared spectroscopy and ammonia temperature-programmed desorption. Subsequently, the experimental conditions were studied and optimized, such as metal species, iron ion concentration, reaction time and temperature, volume ratio of organic phase to water phase and ratio of substrate to catalyst. The results showed that under conditions of 160 °C, 50 mg catalyst, 100 mg xylan and 7 mL reaction solvent, the yield of furfural could reach 78.94% after 3 h of reaction. This study provides an effective research method for the conversion of xylan into furfural, and provides a reference for the catalytic conversion and utilization of hemicellulose in agricultural and forestry biomass. It also provides a feasible method for the resource utilization of agricultural and forestry waste. © 2024 Society of Chemical Industry.

Structure-guided inhibitor design targeting CntL provides the first chemical validation of the staphylopine metallophore system in bacterial metal acquisition

To survive in the metal-scarce environment within the host, pathogens synthesize various small molecular metallophores to facilitate the acquisition of transition metals. The cobalt and nickel transporter (Cnt) system synthesizes and transports staphylopine, a nicotianamine-like metallophore, and serves as a primary transition metal uptake system in Gram-positive bacteria including the human pathogen Staphylococcus aureus. In this study, we report the design of the first inhibitor of the Cnt system by targeting the key aminobutanoyltransferase CntL which is involved in the biosynthesis of staphylopine. Through structure-guided fragment linking and optimization, a class of acceptor-adenosine dual-site inhibitors against S. aureus CntL (SaCntL) were designed and synthesized. The most potent inhibitor, compound 9, demonstrated a ΔTm value of 9.4 °C, a Kd value of 0.021 ± 0.004 μM, and an IC50 value of 0.06 μM against SaCntL. The detailed mechanism by which compound 9 inhibits SaCntL has been elucidated through a high-resolution co-crystal structure. Treatment with compound 9 resulted in a moderate downregulation of intracellular concentrations of iron, nickel, and cobalt ions in the S. aureus cells cultured in the metal-scarce medium, providing the first chemical validation of the important role of Cnt system in bacterial metal acquisition. Our findings pave the way for the development of CntL-based antibacterial agents in future.

Shenqi Tiaoshen Formula alleviates airway inflammation in rats with chronic obstructive pulmonary disease and kidney qi deficiency syndrome by inhibiting ferroptosis via regulating the Nrf2/SLC7A11/GPX4 signaling pathway

To investigate the effects of Shenqi Tiaoshen Formula (SQTSF) for alleviating airway inflammation in rats with both chronic obstructive pulmonary disease (COPD) and lung-kidney qi deficiency syndrome and explore its therapeutic mechanism. Forty-eight SD rats were randomly divided into control group, model group, low-, medium-, and high-dose SQTSF groups, and aminophylline (APL) group. In all but the control group, rat models of COPD with lung-kidney qi deficiency syndrome were established and treated with saline, SQTSF or APL via daily gavage as indicated (starting from day 30). The rats were observed for changes in body weight, grip strength, lung function, lung pathology, inflammatory cytokines in bronchoalveolar lavage fluid (BALF), oxidative stress levels, iron ion metabolism, cellular and mitochondrial ultrastructural changes in the lung tissue, and expressions of Nrf2/SLC7A11/GPX4 signaling pathway and ferroptosis-related proteins. The rats in the model group exhibited obvious symptoms of lung-kidney qi deficiency syndrome with significantly decreased body weight, grip strength, and lung function parameters. Examination of the lung tissue revealed showed significant inflammatory cell infiltration and emphysema with obvious bronchial, perivascular, and alveolar inflammation and alveolar destruction, significantly increased IL-1β, TNF-α, IL-6, and IL-13 levels in BALF, and elevated pulmonary oxidative stress levels and Fe2+ and total iron ion concentrations. The rat models also showed characteristic ultrastructural changes of ferroptosis in the lung tissue cells under transmission electron microscope and significantly decreased Nrf2, GPX4, and SLC7A11 and increased ACSL4 expressions in the lung tissue. Treatment with SQTSF significantly improved these pathological changes in the rat models with a better effect than APL. SQTSF can effectively improve airway inflammation and oxidative stress in COPD rats with lung-kidney qi deficiency possibly by inhibiting ferroptosis via regulating the Nrf2/SLC7A11/GPX4 signaling pathway.

Designed magnetic nanoparticles for ferroptosis: Release of iron ions from metal-organic frameworks modified with iron oxides

The unique chemical properties of the catalytic and biocompatible metal organic framework MIL88b allow for considering it as prooxidant agent. The authors hypothesize whether additional modification of the MIL88b with an additional iron source as Fe3O4 nanoparticles can increase both pro-oxidant activity and provide magnetic properties contributing to target delivery. The prooxidant activity of the Fe3O4-MOF was studied using electron paramagnetic resonance spectroscopy and methylene blue degradation reactions in the presence of hydrogen peroxide. To understand the reaction mechanism, the authors studied the released iron ions, as well as the surface composition using the X-ray photoelectron spectroscopy method. The addition of iron oxide leads to a more prolonged release of iron ions and the production of hydroxyl radicals within 24 h. The native MIL88b demonstrates the highest Fenton reaction rate due to "sacrificial" behavior (despite lower concentration of iron ions in the composition and on the surface compared to the modified sample) and the blocking of the active centers of MIL88b by Fe3O4 on the surface.

Element behavior during autoclave oxidation of polymetallic sulfide flotation concentrate containing tungsten and molybdenum

In this paper, we investigate the behavior of associated elements (tungsten, molybdenum, and bismuth) contained in a sulfide gold-bearing concentrate during its autoclave oxidation. The process is studied using a sulfide flotation concentrate, crushed to a particle sieve mesh size of minus 0.045 mm and containing 22.1 g/t of gold, 133.2 g/t of silver, 2.7% of tungsten, 13% of molybdenum, and 0.7% of bismuth. The process was carried out in a 2 dm3 autoclave at a temperature of 220ºC and an oxygen partial pressure of 0.7 MPa. The concentrations of sulfuric acid and iron ions in the solution were determined by titrimetric analysis. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentrations of bismuth, tungsten, molybdenum, copper, silver, and arsenic in the solution, as well as the content of bismuth, tungsten, molybdenum, copper, arsenic, lead, and iron and sulfur forms in the cake. The cake was also examined using diffraction analysis. Experiments on cyanidation of oxidized cake were carried out in the pH range of 10.0–10.5 and a NaCN concentration of 1 g/dm3 with a PuroliteS992 ion exchange resin for 24 h. Autoclave oxidation experiments showed the sulfide oxidation degree to be higher than 99%. Extraction of molybdenum into solution in the form of [MoO2(SO4)n]-(2n-2) and MoO 2+ amounted to 95%. The decrease in the solid mass led to an increase in the concentration of bismuth and tungsten in the cake, with their contents reaching 1.66% and 12.7%, respectively. The main phases in the cake were established to be scheelite, anhydrite, plumboyarosite, and bedantite. The extraction of precious metals at the subsequent cyanidation stage amounted to 97.5% of gold and 91.6% of silver. Therefore, autoclave cyanide processing of sulfide gold-containing concentrates leads to a molybdenum extraction in the autoclave oxidation solution at the level of 95%. During cyanidation, more than 90% of gold and silver are extracted. Due to the significant amount of tungsten (17%), bismuth (0.9%), lead (5.3%), and molybdenum (3.3%), the obtained cake cannot be considered a waste product.

Chronic hypoxia drives the occurrence of ferroptosis in liver of fat greening (Hexagrammos otakii) by activating HIF-1α and promoting iron production

BackgroundHypoxia caused by global climate change and human activities has become a growing concern eliciting serious effect and damages to aquatic animals. Hexagrammos otakii is usually a victim of hypoxia which caused by high density aquaculture and high nutrient input. The mechanism underlying ferroptosis regulation after hypoxia-stress in liver of H. otakii, however, remains elusive. MethodsFor a duration of 15 days, expose the H. otakii to low concentrations of dissolved oxygen (3.4 ± 0.2 mg/L). Detecting alterations in the H. otakii liver tissue by chemical staining, immunohistochemistry, and electron microscopy. The expression variations of relevant genes in the liver of the H. otakii were simultaneously detected using Western blot and qPCR. A correlation analysis was performed between HIF-1α and iron ion expression in the liver of H. otakii following hypoxic stress. ResultsIn this study, we conducted the whole ferroptosis integrated analysis of H. otakii under chronic hypoxic condition. Reactive oxygen species (ROS) are highly accumulated under the hypoxia treatment (Superoxide Dismutase, SOD; Catalase, CAT), and which results in a significantly enhanced of lipid peroxidation (Lipid Peroxidation, LPO; Malondialdehyde, MDA; Aminotransferase, AST; Alanine aminotransferase, ALT) in liver tissue. The HIF-1α signaling is activated to cope with the hypoxia stress through strategies including changing iron ion concentration (Fe3+ and TFR1) to breaking the oxidation balance (GSH and GSH-Px), and enhancing ferroptosis gene expression (GPX4). The expression of genes related to ferroptosis pathway (DMT1, FTH1, STEAP3, ACSL4, γ-GCS, SLC7A11) is significantly upregulated and associated to the expression of iron and HIF-1α. ConclusionsIt is demonstrated that the HIF-1α/Fe3+/ROS/GPX4 axis is involved in promoting ferroptosis in fat greening hepatocytes following hypoxia-stress. Ultimately, our findings unveil a process by which hypoxic stress strongly encourages ferroptosis by triggering HIF-1α and boosting iron synthesis.

Improvement of fire safety for viscose fabrics based on phytic acid modified tea polyphenols complexed iron ions

In this work, a multifunctional finishing agent named as PATFe was prepared from phytic acid (PA), tea polyphenols (TP), and Fe3+. The optimum weight ratio of PA to TP was determined by exploring the effect on flame retardant and tensile properties of viscose fabrics. Then, the effects of different concentrations of iron ions on the flame retardant and tensile properties of viscose fabrics were further investigated, and finally, multifunctional viscose fabrics, PATFe-9, were prepared. The system was investigated to confer the multifunctional effects on the flame retardant, bacteriostatic, and UV-resistant properties of viscose fabrics under the condition of lower weight gains (about 6.0 wt%). The limiting oxygen index of PATFe-9 reached 33.7 % with a weight gain of 6.1 wt%, and PATFe-9 had an inhibition effect against Staphylococcus aureus, and the ultraviolet protection factor value reached 67. It is worth noting that the breaking force retention rate of this system reached 100 %, which greatly improves the scope of use and added value of viscose fabrics.

Synthesis and NEXAFS and XPS Characterization of Pyrochlore-Type Bi1.865Co1/2Fe1/2Ta2O9+Δ

A cubic pyrochlore with the composition Bi1.865Co1/2Fe1/2Ta2O9+Δ (space group Fd-3m, a = 10.5013(8) Å) was synthesized from oxide precursors using solid-phase reactions. These ceramics are characterized by a porous microstructure formed by randomly oriented grains of an elongated shape with a longitudinal size of 0.5–1 µm. The electronic state of cobalt and iron ions in oxide ceramics was studied by NEXAFS and XPS spectroscopy. The parameters of the XPS spectra of Bi4f, Bi5d, Ta4f, Co2p, and Fe2p ionization thresholds for a complex pyrochlore were compared with the parameters of the corresponding oxides of the transition elements. The energy position of the XPS-Ta4f and -Ta5p spectra is shifted towards lower energies compared to the binding energy in tantalum(V) oxide by 0.75 eV. According to XPS spectroscopy, bismuth and tantalum cations have the corresponding effective charge of +3 and +(5-δ). The NEXAFS-Fe2p spectrum of ceramics coincides with the spectrum of Fe2O3 in its main spectrum characteristics and indicates the content of iron ions in the oxide ceramics in the form of octahedral Fe(III) ions, and according to the character of the Co2p spectrum, cobalt ions are predominantly in the Co(II) state.

Dual approach in textile wastewater treatment: optimisation and comparison of fluidised-bed and conventional Fenton processes

ABSTRACT This study optimises secondary textile dyeing wastewater removal using fluidised-bed Fenton (FBR-Fenton) and standard Fenton processes for chemical oxygen demand (COD) and colour removal efficiency. The Box–Behnken response surface approach optimised pH, iron ion concentration, and hydrogen peroxide concentration. At pH 3.3, [Fe2+] = 2.6 mm, [H2O2] = 6.4 mm in the fluidised bed reactor with 67 g/L quartz sand, with a 50% bed expansion after 40 min, the FBR-Fenton process removed 75.8% COD and 98.0% colour. The standard Fenton method was tuned to pH 3.2, [Fe2+] = 3.1 mm, [H2O2] = 6.6 mm, and COD and colour removal effectiveness of 69.7% and 97.5%, respectively. FBR-Fenton enhanced COD and total iron removal efficiency, reduced chemicals, and reduced sludge by 28.0% compared to conventional Fenton. This study also showed quartz sand reusability in FBR-Fenton treatment cycles. Experimental results matched response surface model predictions, proving regression equation correctness.

High-throughput screening of green amino acid and surfactant mixtures with high corrosion inhibition efficiency: Experimental and modelling perspectives

A high-throughput screening method is developed for rapid evaluation of corrosion inhibitors. By employing a fluorometric technique, this method quickly assesses the concentration of iron ions converted from corrosion products in the reaction pool to rapidly evaluate the corrosion inhibition performance of amino acid and surfactants. Utilizing this high-throughput screening platform, the corrosion inhibition effects of L-cysteine mixed with quaternary ammonium salts of different alkyl chain length were evaluated, and their optimal mixing ratios were determined. Through corrosion experiments and molecular simulations, the synergistic mechanisms of the inhibitor mixtures are revealed.