Electron transferring with oxygen defects on Ni-promoted Pd/Al2O3 catalysts for low-temperature lean methane combustion.

Methane (CH4) is the second most consequential greenhouse gas after CO2, with a substantial global warming potential. The CH4 catalytic combustion offers an efficient method for the elimination of CH4. However, improving the catalytic performance of Pd-based materials for low-temperature CH4 combustion remains a big challenge. In this study, we synthesized an enhanced Pd/5NiAlOx catalyst that demonstrated superior catalytic activity and improved water resistance compared to the Pd/Al2O3 catalyst. Specifically, the T90 was decreased by over 100 °C under both dry and wet conditions. Introducing Ni resulted in an enormously enhanced number of oxygen defects on the obtained 5NiAlOx support. This defect-rich support facilitates the anchoring of PdO through increased electron transfer, thereby inhibiting the production of high-valence Pd(2+δ)+ and stimulating the generation of unsaturated Pd sites. Pd0 can effectively activate surface oxygen and PdO plays a significant role in activating CH4, resulting in high activity for Pd/5NiAlOx. On the other hand, the increased water resistance of Pd/5NiAlOx was mainly due to the generation of *OOH species and the lower accumulation of surface -OH species during the reaction process.

Experimental study on the treatment of acid mine drainage containing heavy metals with domestic waste pyrolysis ash.

Acid mine drainage (AMD) is a special kind of acidic wastewater produced in the process of mining and utilization. In this study, AMD was treated using the adsorption method. Domestic waste was prepared by pyrolysis, and the resulting waste pyrolysis ash adsorbent was studied experimentally by a static adsorption test to treat metal ions in AMD. The results showed that the maximum adsorption amounts of Zn2+, Cu2+, Mn2+, Fe2+, Pb2+, and Cd2+ reached 0.425, 0.593, 0.498, 18.519, 0.055, and 0.039 mg/g, respectively, when the amount of pyrolysis ash was added at 30 g/L, the initial pH of the water was 4.1 and the reaction time was 150 min. It was found that the waste pyrolysis ash could be reused at least three times by using Na2S as the regeneration agent. The SEM and BET characterization results prove that its large specific surface areas and well-developed pore structures have the potential to promote the adsorption of metal ions. The pseudo-second-order kinetic equation and Freundlich adsorption isotherms fit the adsorption process well, and the experiments reveal that the metal ions in AMD are well treated by waste pyrolysis ash through adsorption, flocculation and chemical precipitation. Waste pyrolysis ash has great potential for the treatment of acid mine drainage, providing a new approach to solid waste disposal and new ideas for water treatment as a low-cost alternative material.

Study of Modified Dry Desulfurization Ash in a Power Plant for Sequestering CO2 from a Micron-Nanoscale Perspective.

To improve the CO2 fixation ability of dry desulfurization ash (DDA), a DDA must be modified by chemical methods. At the micron level, the changes in microstructure and chemical composition before and after DDA modification were analysed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS), and the reaction mechanism of the modification process was inferred. On the other hand, the chemical and mineral phase compositions of the modified DDA and its solid products were analysed by X ray Fluorescence (XRF) and X-ray diffraction (XRD). In addition, the microstructure of the modified DDA before and after sequestration at nanometre resolution was studied by SEM-EDS so that the curing mechanism of the modified DDA was clearly defined. Then, the effects of the solid-liquid ratio, temperature, pressure and reaction time on the sequestration of CO2 in the modified DDA were studied with aqueous carbonation. The results showed that the higher the temperature is, the higher the solid-liquid ratio, and the lower initial pressure is, the less the CO2 sequestered in the modified DDA and the less the carbon sequestration capacity of the modified DDA. Under the experimental conditions, the carbonation efficiency of the modified DDA could reach 94.42%, and 1 ton of modified DDA could sequester up to 50.61 kg CO2. Compared with conventional DDA, the carbon sequestration capacity is effectively improved. The kinetic data confirmed that the fitting correlation of the quasi-first-order kinetics equation is more significant. The smaller the solid-liquid ratio is, the lower the temperature, the higher the initial pressure, and the higher the rate constant of the quasi-first-order kinetics equation.

Formulation of injectable glycyrrhizic acid-hydroxycamptothecin micelles as new generation of DNA topoisomerase I inhibitor for enhanced antitumor activity.

To develop a new drug delivery system is one of the useful approaches to break through the limitation of hydroxycamptothecin (HCPT), a typical DNA topoisomerase I (Topo I) inhibitor in clinical appliance. Injectable glycyrrhizic acid-hydroxycamptothecin (GL-HCPT) micelles that were able to dramatically improve the solubility and stability of HCPT were prepared through self-assembly process and evaluated both in vitro and in vivo. With a mean particle size (PS) of 105.7 ±â€¯9.7 nm and a drug loading (DL) of 9.0 ±â€¯1.5%, GL-HCPT micelles were rapidly internalized by HepG2 cells after 1 h, significantly increasing the intracellular accumulation of HCPT. Compared with the current used HCPT injection and HCPT/GL physical mixture, GL-HCPT micelles showed enhanced antitumor activity against liver cancer cells (HepG2 and Huh7) as well as a superior suppression on the tumor growth of HepG2 tumor bearing mice. Interestingly, GL-HCPT micelles gathered in liver and simultaneously reduced the drug accumulation in normal tissues, thereby exhibiting minimal cytotoxicity to human normal liver cells (LO2). Therefore, we offered a convenient and cost-effective strategy to construct an intravenous drug delivery system (GL-HCPT micelles) as new generation of DNA Topo I inhibitor for enhanced cancer chemotherapy.

The selective effect of glycyrrhizin and glycyrrhetinic acid on topoisomerase IIα and apoptosis in combination with etoposide on triple negative breast cancer MDA-MB-231 cells.

Triple negative breast cancer(TNBC) has generated growing interests due to its aggressive biologic behavior and absence of targeted therapy approach. Glycyrrhizin(GL) from licorice root and its metabolite, glycyrrhetinic acid(GA) have shown extensive bioactivities in clinic. Here, we demonstrate that GL and GA have contrary anti-cancer effect on TNBC MDA-MB-231 cells. Beside its inhibition of cell proliferation, GA at non-cytotoxic concentration showed synergistic effect in combination with anti-cancer drug, etoposide(VP-16). Specifically, GA enhanced cytotoxicity through regulating topoisomerase IIα(TOPO 2A) targeted by etoposide. GA sensitized the cells to etoposide through elevating TOPO 2A with a 2.4 fold rate at 12h. From 12 to 48h, GA halved the expression of TOPO 2A and stimulated apoptosis, which exhibited its antineoplastic effect. Our experiments showed that GSH depletion, modulation of MAPK and AKT pathways accounted for the regulation of topoisomerase IIα and apoptosis. However, GL showed protection and detoxication by decreasing reactive oxygen species generation, maintaining GSH and differentially modulating apoptosis, AKT pathway, ERK and JNK of MAPK pathway. Collectively, our results demonstrate that GA, instead of GL, is a better candidate for TNBC treatment because of its anti-cancer effect and sensitization of topoisomerase IIα inhibitor.