Which kind of feedback has a greater impact on individuals with social anxiety: facial or textual? An ERP study.

The present study is the first to compare the examined electrophysiological activity of facial and textual feedback of students with social anxiety after they finished a visual search task. Compared to textual feedback, facial feedback is much more effective. Specifically speaking, positive facial feedback caused stronger feedback-related negativity (FRN), and negative facial feedback caused late positive potential (LPP) of stronger amplitude. These changes in the FRN component (associated with feedback) and LPP (related to controlled attention engagement) provide clues about the interplay between anxiety and attention allocation in processing facial feedback. The results have implications for identifying the feedback format that will be most helpful for individuals with social anxiety.

Enhanced phycocyanin and DON removal by the synergism of H2O2 and micro-sized ZVI: Optimization, performance, and mechanisms.

Micro-sized zero-valent iron (mZVI) has proven effective for phycocyanin (PC) removal, but efficiency needs to be enhanced. Here, hydrogen peroxide (H2O2) was used to enhance PC removal by mZVI and the corresponding mechanisms are discussed. The results showed that H2O2 could effectively enhance PC removal by mZVI and the PC removal efficiency increased from 37.8% to 80.6% with 1.5 g/L mZVI in 60 min reaction time. The trends of dissolved organic nitrogen (DON) removal were consistent with PC removal. Low pH value, high mZVI dosage, and a suitable amount of H2O2 were conducive to PC removal. The SEM-mapping indicated that PC removal was not primarily by adsorption. Similarly, no obvious change was observed in PC molecular structure based on fluorescence spectroscopy and SDS-PAGE analyses. However, the PC removal mechanism could be inferred from the variation of iron concentration in the process. The coagulation of dissolved iron ions dissolved from mZVI was the main removal pathway. The OH oxidation only accounted for 20% of PC removal. PC removal led to the reduction of disinfection by-products with similar efficiency. The combination of mZVI and H2O2 is a promising strategy for the simultaneous removal of PC and DON in drinking water treatments.

Preparation of an Au-TiO2 photocatalyst and its performance in removing phycocyanin.

A novel TiO2 photocatalyst (Au-TiO2 composite film) with enhanced photocatalytic activity has been synthesized, characterized and its performance in the removal of phycocyanin (PC) was investigated. The results show that the Au-TiO2 composite film has a lower electron-hole recombination rate, wider optical response range and high electron transfer rate. The photocatalytic activity of the as-prepared Au-TiO2 composite photocatalyst was observed to be enhanced with the removal efficiency of PC and dissolved organic nitrogen found to be 96.7% and 59%, respectively using the UV/Au-TiO2 process. In addition, the combination of photocatalytic pretreatment and coagulation can achieve an enhanced removal efficiency. The Au-TiO2 photocatalyst was found to decrease the dichloroacetonitrile formation potential (105.9 to 79.3 µg/L), however, it exacerbated the production of trichloromethane and dichloroacetamide beyond their initial levels (116.7 to 224.9 µg/L and 2.27 to 2.31 µg/L, respectively). The divergent trends of these disinfection by-products are due to the fundamental differences in the precursor material.

Removal efficiency and mechanism of phycocyanin in water by zero-valent iron.

The efficiencies and mechanism of phycocyanin removal from water by zero-valent iron (ZVI) were studied. The trend for dissolved organic nitrogen removal was similar to phycocyanin and the removal efficiency was high at ∼81% and 95%, respectively, in 90 min. The experimental results showed that the phycocyanin removal efficiency was higher at pH < 6, with an almost complete removal. However, only 68% was removed at pH 9. Within 30 min, the removal efficiency of phycocyanin for 1-4 tested cycles was reduced from 55.8% to 15.2%. Scanning electron microscopy and energy dispersive spectroscopy, Fourier transform infrared spectroscopy analysis and X-ray photoelectron spectroscopy were used to analyze the mechanisms of phycocyanin removal, which indicated that a small amount of phycocyanin was immobilized on the ZVI surface by adsorption. In addition, the main removal pathway was coagulation by dissolved iron ions. The Fe oxide formed in situ from ZVI had a higher removal efficiency than that in FeCl3, which can play improved roles in charge neutralization. The production of disinfection byproducts also decreased because of the decrease of precursors.