Understanding the effects of A-site Ag-doping on LaCoO3 perovskite for NO oxidation: Structural and magnetic properties.

The partial substitution of A-site in perovskites is a major strategy to enhance the catalytic oxidation activity. This study explores the use of silver (Ag) to partially replace the lanthanum (La) ion at the A-site in LaCoO3 perovskite, investigating the role of Ag in the ABO3 perovskite structure, elucidating the nitric oxide (NO) oxidation mechanism over La1-xAgxCoO3 (x = 0.1-0.5) perovskites. La0.7Ag0.3CoO3 with an Ag-doping amount of 0.3, exhibited the highest NO oxidation activity of 88.5% at 275 °C. Characterization results indicated that Ag substitution enhanced the perovskite, maintaining its original phase structure, existing in the form of a mixture of Ag0 and Ag+ in the La1-xAgxCoO3 (x = 0.1-0.5) perovskites. Notably, Ag substitution improved the specific surface area, reduction performance, Co3+, and surface adsorption oxygen content. Additionally, the study investigated the relationship between magnetism and NO oxidation from a magnetism perspective. Ag-doping strengthened the magnetism of La-Ag perovskite, resulting in stronger adsorption of paramagnetic NO. This study elucidated the NO oxidation mechanism over La-Ag perovskite, considering structural and magnetic properties, providing valuable insights for the subsequent development and industrial application of high oxidation ability perovskite catalysts.

Preparation of functional geopolymers from municipal solid waste incineration fly ash: An approach combining experimental and computational simulation studies.

This study aims to evaluate the feasibility and safety of using municipal solid waste incineration fly ash (MSW-IFA) in the development of geopolymer-based solidification/stabilization (S/S) treatments. Geopolymers have garnered attention as a sustainable alternative to traditional cement, owing to their high strength, stability, and minimal CO2 emissions. In this study, a combination of experimental and simulation calculations was used to investigate the setting time, mechanical properties, environmental risks, hydration mechanisms and processes of municipal solid waste incineration fly ash-based polymeric functional cementitious materials (GFCM). The results demonstrate that the mechanical properties of GFCM are related to the changes in the mineral phases and the degree of compactness. Quantum chemical calculations indicate that the hydration products may be [Si(OH)4], [Al(OH)3(OH2)] and [Al(OH)4]-. It is possible that the heavy metals are embedded in the hydrated silica-aluminate by electrostatic interaction or chemisorption. Heavy metals may be embedded in hydrated silica-aluminate by electrostatic action or chemisorption. This study provides a feasible method for resource utilization and heavy metal stabilization mechanism of MSW-IFA.

Ring finger protein 126 promotes breast cancer metastasis and serves as a potential target to improve the therapeutic sensitivity of ATR inhibitors.

BACKGROUND/AIMS: This study explores the relationship between the E3 ubiquitin ligase Ring finger protein 126 (RNF126) and early breast cancer metastasis and tests the hypothesis that RNF126 determines the efficacy of inhibitors targeting Ataxia telangiectasia mutated and Rad3-related kinase (ATR). METHODS: Various metastasis-related genes were identified by univariable Cox proportional hazards regression analysis based on the GSE11121 dataset. The RNF126-related network modules were identified by WGCNA, whereas cell viability, invasion, and migration assays were performed to evaluate the biological characteristics of breast cancer cells with or without RNF126 knockdown. MTT, immunoblotting, immunofluorescence, and DNA fiber assays were conducted to determine the efficiency of ATR inhibitor in cells with or without RNF126 knockdown. RESULTS: RNF126 was associated with early breast cancer metastasis. RNF126 promoted breast cancer cell proliferation, growth, migration, and invasion. ATR inhibitors were more effective at killing breast cancer cells with intact RNF126 due to replication stress compared with the corresponding cells with RNF126 knockdown. Cyclin-dependent kinase 2 (CDK2) was involved in regulating replication stress in breast cancer cells with intact RNF126. CONCLUSION: A high level of expression of RNF126 in early breast cancer patients without lymph node metastases may indicate a high-risk type of metastatic disease, possibly due to RNF126, which may increase breast cancer cell proliferation and invasion. RNF126-expressing breast cancer cells exhibit CDK2-mediated replication stress that makes them potential targets for ATR inhibitors.

Inorganic flocculant for sludge treatment: Characterization, sludge properties, interaction mechanisms and heavy metals variations.

As an industrial waste, phosphogypsum was modified to produce flocculant for sludge dewatering. In this paper, characteristics of flocculant, properties of treated sludge, and interactions of sludge and flocculant were investigated. Results suggested that after modification, flocculant showed a positive electrical property and a porous structure. Besides, larger sludge flocs formed in treated sludge showed a higher settleability and filterability. Flocculant could narrow sludge colloid network by compressing its Electrical double-layer due to the presence of CaSO4. With potential change, the electronegative colloidal network cracked quickly and released sludge particles, active groups, unstable heavy metals and 82.91% of bound water. Moreover, porous adsorption between sludge particles and flocculant was found under molecular electrostatic potential and Van Der Waals force caused by flocculant addition. After modification, shear modulus of CaSO4, SiO2 and Al2O3 in modified phosphogypsum increased by 21%, 23% and 17%, respectively. This provided a strong skeleton support for sludge particles, which is significant to sludge dewatering. Particularly, through chelation, adsorption and rolling-sweeping process, risk level of unstable heavy metals excepting Cu in sludge filter cake was largely weakened. Immobilized rate of risky heavy metals was 23.96% (CdF1/F2), 39.92% (CrF1), 11.11% (PbF1/F2), 21.21% (ZnF1), 35.49% (NiF1/F2), and 78.61% (AsF1/F2), respectively. Therefore, this study provided significant insight for developing efficient method to promote bound water removal from sludge, and to stabilize risky heavy metals in sludge.

Research on the variations of organics and heavy metals in municipal sludge with additive acetic acid and modified phosphogypsum.

Concentration and fraction distribution of organics and heavy metals in municipal sludge treated by modified phosphogypsum and acetic acid (signed as MPG/HAC) were studied. The results showed that MPG/HAC conditioning significantly produce synergistic enhancement effect to dissolution of unstable heavy metals wrapped in the stable colloid network. Simultaneously, after conditioning, about 45.16% of organics such as proteins, polysaccharides and humic acid in supernatant was degraded, thus dissociating large amount of active group which accelerated immobilization of dissolved heavy metals and weaken its toxicity. In addition, MPG with a porous structure could adsorb unstable heavy metals and transform them into residual fraction, leading to a considerable decrease in their mobility risk level. Besides, linear regression models showed that a strong oxidizability of sludge, and destruction of colloidal network could greatly promote dissolution of unstable heavy metals. Simultaneously, sludge oxidizability and organics degradation rate, and disintegration of extracellular polymeric substances (EPS) layer highly accelerate immobilization of unstable metals. Excepting Cd, environmental risk of Cr, Cu, Pb, Zn, Ni and As can be effectively weakened after conditioning. Additionally, MPG/HAC conditioning might be appropriate for stabilization of Cd, Cr and Zn in water supply sludge, especially for Zn.

Research on dewaterability and properties of sewage sludge under modified phosphogypsum and acetic acid pretreatments.

A combined modified phosphogypsum (MPG) and acetic acid (HAC) addition was performed to pretreat sewage sludge for better dewaterability, and dewatering performance, sludge flocs morphology, properties of treated sludge, composition and morphology distribution of extracellular polymeric substances (EPS), bound water release dynamic were investigated. Results suggested that combined addition could highly improve sludge dewatering compared to single addition. Furthermore, after pretreatment, stable sludge network was disintegrated and massive loosely bound EPS (LB-EPS) were destroyed into supernatant, thus increasing amount of organics with molecular weight between 1000 and 7000 Da in soluble EPS (SB-EPS). Simultaneously, about 9.5 kg kg-1 DS (Dry solids) of bound water was released from sludge network.

Investigation on extracellular polymeric substances, sludge flocs morphology, bound water release and dewatering performance of sewage sludge under pretreatment with modified phosphogypsum.

Modified phosphogypsum (MPG) was developed to improve dewaterability of sewage sludge, and dewatering performance, properties of treated sludge, composition and morphology distribution of EPS, dynamic analysis and multiple regression model on bound water release were investigated. The results showed that addition of MPG caused extracellular polymeric substances (EPS) disintegration through charge neutralization. Destruction of EPS promoted the formation of larger sludge flocs and the release of bound water into supernatant. Simultaneously, content of organics with molecular weight between 1000 and 7000 Da in soluble EPS (SB-EPS) increased with increasing of EPS dissolved into the liquid phase. Besides, about 8.8 kg•kg-1DS of bound water was released after pretreatment with 40%DS MPG dosage. Additionally, a multiple linear regression model for bound water release was established, showing that lower loosely bond EPS (LB-EPS) content and specific resistance of filtration (SRF) may improve dehydration performance, and larger sludge flocs may be beneficial for sludge dewatering.