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Journal of the American Chemical Society Jun 2024Identifying the active phase with the highest activity, which is long-believed to be a steady state of the catalyst, is the basis of rational design of heterogeneous...
Identifying the active phase with the highest activity, which is long-believed to be a steady state of the catalyst, is the basis of rational design of heterogeneous catalysis. In this work, we performed detailed investigations, successfully capturing the instantaneous structure-activity change in oscillating Pd nanocatalysts during methane oxidation, which reveals an unprecedented oscillatory active state. Combining quantitative environmental transmission electron microscopy and highly sensitive online mass spectrometry, we identified two distinct phases for the reaction: one where the Pd nanoparticles refill with oxygen, and the other, a period of abrupt pumping of oxygen and boosted methane oxidation within about 1 s. It is the rapid reduction process that shows the highest activity for total oxidation of methane, not a PdO or Pd steady state under the conditions applied here (methane:oxygen = 5:1). This observation challenges the traditional understanding of the active phase and requires a completely different strategy for catalyst optimization.
PubMed: 38942067
DOI: 10.1021/jacs.4c02830 -
Environmental Monitoring and Assessment Jun 2024Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the...
Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the performance of simultaneous degradation of the mixed pollutants (amoxicillin, acetaminophen, and ciprofloxacin) for an aqueous solution using the solar Fenton process. Operating parameters such as pH, iron doses, HO doses, pollutant concentrations, and time were studied. From the experimental results, the ideal conditions were obtained for the removal of mixed pollutants such as pH 3, Fe 0.04 mM, HO 4 mM, the concentration of the mixed pollutants 5 mg/L, solar radiation 400 W/m, and time 10 min, respectively. The pseudo-first-order kinetics were utilized to investigate the degradation efficacy of the mixed pollutants. The result of the study indicates that the degradation efficiency was > 99% for the mixed pollutants. A maximum of 63% mineralization was observed, and hydroxyl radical scavenger effects were studied. The best optimal conditions were applied to assess the spiked wastewater (municipal wastewater (MWW) and hospital wastewater (HWW)). The highest elimination rates for AMX, ACET, and CIP were observed as 65%, 89%, and 85% for MWW and 76%, 92%, and 80% for HWW, respectively. The degraded by-products were detected by LC-ESI-MS in the water matrix (aqueous solution and spiked wastewater), and ECOSAR analysis was performed for the transformed products. The study concluded that the solar Fenton technique is promising and effective for the removal of mixed pollutants from the water matrix.
Topics: Water Pollutants, Chemical; Hydrogen Peroxide; Kinetics; Iron; Waste Disposal, Fluid; Sunlight; Wastewater; Oxidation-Reduction; Ciprofloxacin; Acetaminophen; Amoxicillin
PubMed: 38942963
DOI: 10.1007/s10661-024-12837-2 -
Science Bulletin Jun 2024
PubMed: 38942697
DOI: 10.1016/j.scib.2024.06.006 -
Environmental Geochemistry and Health Jun 2024Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting...
Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting effectiveness of coating agents on the oxidation of iron sulfide minerals was investigated using pyrite and rock samples resulting from acid drainage. The film formed with both surface-coating agents was identified by pyrite surface analysis. It was also confirmed that the formation of coatings varies depending on the crystallographic orientation. The inhibitory effects under rainy and submerged conditions were investigated using column experiments. Submerged conditions accelerated deterioration compared to that under rainy conditions. Iron phosphate coating had a significantly better oxidation-inhibitory effect (84.86-98.70%) than iron silicate coating (56.80-92.36%), and at a concentration of 300 mM, H elution was inhibited by more than 90% throughout the experiment. Furthermore, methods for effective film formation were investigated in terms of producing Fe; (1) application of coating agents mixed with oxidant (HO), (2) application of coating agent after the use of the oxidant. In a rainy environment, applying iron phosphate-based coating using the sequential method showed oxidation inhibition effects for cycles 1-9, whereas applying the mixed material showed effects for cycles 9-13. The use of a surface-coating agent after applying an oxidant did not inhibit oxidation. The surface coating agent and the oxidizing agent should be applied as a mixture to form a film.
Topics: Silicates; Iron; Phosphates; Oxidation-Reduction; Acid Rain; Sulfides; Hydrogen Peroxide; Ferric Compounds
PubMed: 38941030
DOI: 10.1007/s10653-024-01996-3 -
Inorganic Chemistry Jun 2024Chemical equilibrium stands as a fundamental principle governing the dynamics of chemical systems. However, it may become intricate when it refers to nanomaterials...
Chemical equilibrium stands as a fundamental principle governing the dynamics of chemical systems. However, it may become intricate when it refers to nanomaterials because of their unique properties. Here, we invesitigated concave gold nanocubes (CGNs) subjected to an akaline Au/HO solution, which exhibit both etching and growth in a monotonic solution. When CGNs were subjected to an increasingly alkaline Au/HO solution, their dimensions increased from 107 to 199 nm and then decreased to 125 nm. Transmission electron microscopy (TEM) demonstrated that their morphology undergoes intricate alternations from concave to mutibranch and finally to concave again. Real-time ultraviolet-visible spectroscopy and time-dependent TEM also demonstrated reduction first and then oxidation in one solution. Among the nanomaterials, the obtained carpenterworm-like gold nanoparticles revealed the best catalytic performance in -nitrophenol reduction by NaBH, with a chemical rate that continues to increase until the reaction reaches completion. Growth leading to atomic dislocation, distortion, and exposure on nanoparticles and the redox of HO plausibly account for the further etching due to the Ostwald ripening effect. Our study may spur more interest in the tuning of the properties, engineering, investigation, and design of new kinds of nanomaterials.
PubMed: 38940642
DOI: 10.1021/acs.inorgchem.4c02346 -
Dalton Transactions (Cambridge, England... Jun 2024The extraction and recovery of valuable metals from various spent catalysts bioleaching represents a green, low-carbon and eco-friendly process. However, the pulp...
The extraction and recovery of valuable metals from various spent catalysts bioleaching represents a green, low-carbon and eco-friendly process. However, the pulp density of spent catalysts is usually 1.0% or lower owing to their toxicity, denoting low process capacity and poor practical potential. In this study, an intensified bioleaching strategy was used for the first time to promote the release efficiencies of both Co and Mo from a spent Co-Mo catalyst at a high pulp density of 10% by supplementing extracellular polymeric substances (EPSs). The results showed that the addition of 0.6 g L EPSs harvested a maximum release of 73.6% for Co and 72.5% for Mo after 9 days of contact, with an evident elevation of 22.6% for Co and 24.4% for Mo, in contrast to no addition, respectively. The added EPS not only promoted the growth of plankton cells to produce more active molecules but also boosted the adhesion of leaching cells to the spent catalyst to form stable aggregates. Moreover, the resulting aggregates allowed for the gathering and confinement of the active small molecules, including Fe and Fe, inside the micro-areas between the spent catalysts and the cells for quick electronic transfer as an interface oxidation/reduction reaction to free both Co and Mo from the spent catalyst.
PubMed: 38940617
DOI: 10.1039/d4dt00104d -
Oncology Reports Aug 2024Ferroptosis, a regulated form of cell death, is intricately linked to iron‑dependent lipid peroxidation. Recent evidence strongly supports the induction of ferroptosis... (Review)
Review
Ferroptosis, a regulated form of cell death, is intricately linked to iron‑dependent lipid peroxidation. Recent evidence strongly supports the induction of ferroptosis as a promising strategy for treating cancers resistant to conventional therapies. A key player in ferroptosis regulation is ferroptosis suppressor protein 1 (FSP1), which promotes cancer cell resistance by promoting the production of the antioxidant form of coenzyme Q10. Of note, FSP1 confers resistance to ferroptosis independently of the glutathione (GSH) and glutathione peroxidase‑4 pathway. Therefore, targeting FSP1 to weaken its inhibition of ferroptosis may be a viable strategy for treating refractory cancer. This review aims to clarify the molecular mechanisms underlying ferroptosis, the specific pathway by which FSP1 suppresses ferroptosis and the effect of FSP1 inhibitors on cancer cells.
Topics: Humans; Neoplasms; Ferroptosis; S100 Calcium-Binding Protein A4; Ubiquinone; Lipid Peroxidation; Drug Resistance, Neoplasm; Animals; Glutathione; Antineoplastic Agents; Molecular Targeted Therapy
PubMed: 38940330
DOI: 10.3892/or.2024.8764 -
Biomeditsinskaia Khimiia Jun 2024Electrochemical profiling of formaldehyde-inactivated poliovirus particles demonstrated a relationship between the D-antigen concentration and the intensity of the...
Electrochemical profiling of formaldehyde-inactivated poliovirus particles demonstrated a relationship between the D-antigen concentration and the intensity of the maximum amplitude currents of the poliovirus samples. The resultant signal was therefore identified as electrochemical oxidation of the surface proteins of the poliovirus. Using registration of electrooxidation of amino acid residues of the capsid proteins, a comparative electrochemical analysis of poliovirus particles inactivated by electrons accelerated with doses of 5 kGy, 10 kGy, 15 kGy, 25 kGy, 30 kGy at room temperature was carried out. An increase in the radiation dose was accompanied by an increase in electrooxidation signals. A significant increase in the signals of electrooxidation of poliovirus capsid proteins was detected upon irradiation at doses of 15-30 kGy. The data obtained suggest that the change in the profile and increase in the electrooxidation signals of poliovirus capsid proteins are associated with an increase in the degree of structural reorganization of surface proteins and insufficient preservation of the D-antigen under these conditions of poliovirus inactivation.
Topics: Poliovirus; Capsid Proteins; Virus Inactivation; Oxidation-Reduction; Formaldehyde; Humans; Virion
PubMed: 38940205
DOI: 10.18097/PBMC20247003161 -
Journal of Integrative Neuroscience Jun 2024Excessively high or synchronized neuronal activity in the brain is the underlying cause of epilepsy, a condition of the central nervous system. Epilepsy is caused mostly... (Review)
Review
Excessively high or synchronized neuronal activity in the brain is the underlying cause of epilepsy, a condition of the central nervous system. Epilepsy is caused mostly by an imbalance in the activity of inhibitory and excitatory neural networks. Recurrent or prolonged seizures lead to neuronal death, which in turn promotes epileptogenesis and epileptic seizures. Ferrous ion-mediated cell death is known as ferroptosis, which is due to the accumulation of lipid peroxidation products resulting from compromise of the glutathione (GSH)-dependent antioxidant system. The pathophysiology of epilepsy has been linked to anomalies in the glutathione peroxidase 4 (GPX4)/GSH redox pathway, lipid peroxidation, and iron metabolism. Studies have shown that inhibiting ferroptosis may alleviate cognitive impairment and decrease seizures, indicating that it is neuroprotective. With the hope of aiding the development of more novel approaches for the management of epilepsy, this research aimed to examine the role of ferroptosis in this disease.
Topics: Ferroptosis; Humans; Epilepsy; Animals; Lipid Peroxidation; Iron
PubMed: 38940095
DOI: 10.31083/j.jin2306113 -
Frontiers in Bioscience (Landmark... Jun 2024The endoplasmic reticulum (ER) played an important role in the folding, assembly and post-translational modification of proteins. ER homeostasis could be disrupted by... (Review)
Review
The endoplasmic reticulum (ER) played an important role in the folding, assembly and post-translational modification of proteins. ER homeostasis could be disrupted by the accumulation of misfolded proteins, elevated reactive oxygen species (ROS) levels, and abnormal Ca2+ signaling, which was referred to ER stress (ERS). Ferroptosis was a unique programmed cell death model mediated by iron-dependent phospholipid peroxidation and multiple signaling pathways. The changes of mitochondrial structure, the damage of glutathione peroxidase 4 (GPX4) and excess accumulation of iron were the main characteristics of ferroptosis. ROS produced by ferroptosis can interfere with the activity of protein-folding enzymes, leading to the accumulation of large amounts of unfolded proteins, thus causing ERS. On the contrary, the increase of ERS level could promote ferroptosis by the accumulation of iron ion and lipid peroxide, the up-regulation of ferroptosis related genes. At present, the studies on the relationship between ferroptosis and ERS were one-sided and lack of in-depth studies on the interaction mechanism. This review aimed to explore the molecular mechanism of cross-talk between ferroptosis and ERS, and provide new strategies and targets for the treatment of liver diseases.
Topics: Ferroptosis; Humans; Endoplasmic Reticulum Stress; Liver Diseases; Reactive Oxygen Species; Animals; Signal Transduction; Iron; Lipid Peroxidation; Endoplasmic Reticulum
PubMed: 38940044
DOI: 10.31083/j.fbl2906221