Experimental Design Technique on Removal of Hydrogen Sulfide using CaO-eggshells Dispersed onto Palm Kernel Shell Activated Carbon：Experiment,Optimization,Equilibrium and Kinetic Studies

This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.

Low- and high-dose hydrogen peroxide regulation of transcription factor NF-E2-related factor 2

Background Reactive oxygen species （ROS） may play both physiological and pathophysiological roles. Transcription factor NF-E2-related factor 2 （Nrf2） regulates antioxidant response element （ARE）-mediated genes expression and coordinates induction of chemoprotective proteins in response to physical and chemical stresses. The exact role of Nrf2 in cellular responses to different levels of oxidative stresses remains unknown. Methods Rat pulmonary microvascular endothelial cells were cultured and treated with 0 mmol/L, 0.125 mmol/L, 0.25 mmol/L, 0.5 mmol/L, 1.0 mmol/L and 2.0 mmol/L hydrogen peroxide solution for 2 hours. Nrf2 gene expression was assayed by reverse transcription-PCR, Nrf2-ARE binding activity was assayed with electrophoretic mobility shift assay （EMSA）, and localization of Nrf2 was detected with immunohistochemistry. Results Low and moderate （0.125 mmol/L, 0.25 mmol/L and 0.5 mmol/L） doses hydrogen peroxide exposure of rat pulmonary microvascular endothelial cells led to the nuclear accumulation of Nrf2, increased activity of transcription regulation and up-regulation of ARE-medicated gene expression. In contrast, high doses of hydrogen peroxide （1 mmol/L 2 mmol/L） exposure of the cells led to the nuclear exclusion of Nrf2, decreased activity transcription regulation and down-regulation of ARE-mediated gene expression. Conclusion Low and moderate doses of hydrogen peroxide play protective roles by increasing transcription activity of Nrf2, whereas high- dose hydrogen peroxide plays a deleterious role by decreasing transcription activity of Nrf2.

Assembly of Highly Ordered 2D Arrays of Silver-PNIPAM Hybrid Microgels

A strategy was developed for the synthesis of highly ordered 2D arrays of Ag-PNIPAM hybrid microgel. The highly ordered 2D arrays of PNIPAM microgel were prepared by dispersing PNIPAM microgel on a charge-reversible substrate. The microgel spheres self-assembled into a 3D colloidal crystal, and the first 111 plane was fixed in situ onto the substrate as a result of spontaneous charge reversal of the substrate, leaving a high-quality 2D array of PNIPAM microgel. Ag nanoparticles were then synthesized in situ inside the microgel spheres by introduction of Ag＋ ions into the microgel spheres and reduction with sodium borohydride. The resulting 2D arrays are highly ordered. The inter-particle distance in the array can be tuned. In addition, the method allows the synthesis of large size arrays and the use of nonplanar substrate.