CO2 Activation on Ni(111) and Ni(110) Surfaces in the Presence of Hydrogen.

The structure sensitivity of CO2 activation in the presence of H2 has been identified by ambient-pressure X-ray photoelectron spectroscopy (APXPS) on Ni(111) and Ni(110) surfaces under identical reaction conditions. Based on the APXPS results and computer simulations, we propose that, around room temperature, the hydrogen-assisted activation of CO2 is the major reaction path on Ni(111), while the redox pathway of CO2 prevails on Ni(110). With increasing temperature, the two activation pathways are activated in parallel. While the Ni(111) surface is fully reduced to the metallic state at elevated temperatures, two stable Ni oxide species can be observed on Ni(110). Turnover frequency measurements indicate that the low-coordinated sites on Ni(110) promote the activity and selectivity of CO2 hydrogenation to methane. Our findings provide insights into the role of low-coordinated Ni sites in nanoparticle catalysts for CO2 methanation.

Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta).

Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation.

Micronuclei and dyskaryosis of erythrocytes and oxidative stress response with endosulfan exposure in topmouth gudgeon Pseudorasbora parva.

Endosulfan is a chlorinated and genotoxic insecticide extensively used worldwide in agriculture. However, residues of endosulfan can be detected in farmland soil and natural water. In this study, toxic effects of endosulfan were studied by measuring micronuclei and dyskaryosis in peripheral erythrocytes of topmouth gudgeon (Pseudorasbora parva). In addition, liver antioxidant enzyme activity and lipid peroxidation level were measured. P. parva were exposed to control and 5 doses (0.12, 0.16, 0.21, 0.31 and 0.62µg/L) of endosulfan for 48h and 96h. The frequencies of micronuclei and dyskaryosis, antioxidant enzyme activity, contents of ROS and lipid peroxidation increased by endosulfan exposure. Compared to controls, frequencies of micronuclei and dyskaryosis were significantly increased with endosulfan exposure, and an obvious dose-response relationship was found. Endosulfan has potential genotoxicity by inducing the oxidative stress and lipid peroxidation, which probably lead to the occurrence of micronuclei and dyskaryosis in erythrocytes.