The currently applied disinfection methods during water treatment provide effective solutions to kill pathogens, but also generate harmful byproducts, which are required to be treated with additional efforts. In this work, an alternative and safer water disinfection system consisting of silver nanoparticle/multiwalled carbon nanotubes (Ag/MWNTs) coated on a polyacrylonitrile (PAN) hollow fiber membrane, Ag/MWNTs/PAN, has been developed. Silver nanoparticles of controlled sizes were coated on polyethylene glycol-grafted MWNTs. Ag/MWNTs were then covalently coated on the external surface of a chemically modified PAN hollow fiber membrane to act as a disinfection barrier. A continuous filtration test using E. coli containing feedwater was conducted for the pristine PAN and Ag/MWNTs/PAN composite membranes. The Ag/MWNT coating significantly enhanced the antimicrobial activities and antifouling properties of the membrane against E. coli. Under the continuous filtration mode using E. coli feedwater, the relative flux drop over Ag/MWNTs/PAN was 6%, which was significantly lower than that over the pristine PAN (55%) at 20 h of filtration. The presence of the Ag/MWNT disinfection layer effectively inhibited the growth of bacteria in the filtration module and prevented the formation of biofilm on the surface of the membrane. Such distinctive antimicrobial properties of the composite membrane is attributed to the proper dispersion of silver nanoparticles on the external surface of the membrane, leading to direct contact with bacterium cells.

New immobilization of the chiral Mn(salen) complex through the complexation of managanese by oxygen atoms of the phenoxyl groups grafted on the surface of MCM-41 leads to a markedly higher ee than for the free complex.

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CO2 electroreduction is of great significance to reduce CO2 emissions and complete the carbon cycle. However, the unavoidable carbonate formation and low CO2 utilization efficiency in neutral or alkaline electrolytes hinder its application at commercial scale. The development of CO2 reduction under acidic conditions provides a promising strategy, but the inhibition of the hydrogen evolution reaction is difficult. Herein, the first work to design a Ni–Cu dual atom catalyst supported on hollow nitrogen‐doped carbon is reported for pH‐universal CO2 electroreduction to CO. The catalyst shows a high CO Faradaic efficiency of ≈99% in acidic, neutral, and alkaline electrolytes, and the partial current densities of CO reach 190 ± 11, 225 ± 10, and 489 ± 14 mA cm−2, respectively. In particular, the CO2 utilization efficiency under acidic conditions reaches 64.3%, which is twice as high as that of alkaline conditions. Detailed study indicates the existence of electronic interaction between Ni and Cu atoms. The Cu atoms push the Ni d‐band center further toward the Fermi level, thereby accelerating the formation of *COOH. In addition, operando characterizations and density functional theory calculation are used to elucidate the possible reaction mechanism of CO2 to CO under acidic and alkaline electrolytes.

In this study we used U0126, a potent and specific inhibitor of MEK, to study the roles of MEK/ERK/p90 rsk signaling pathway in the meiotic cell cycle of mouse oocytes. The phosphorylation of MAP kinase and p90 rsk in the oocytes treated with 1.5 M U0126 was the same as that in oocytes cultured in drug-free medium. With 1.5 M U0126 treatment, the spindles appeared normal as they formed in oocytes, but failed to maintain its structure. Instead, the spindle lost one pole or elongated extraordinarily. After further culture, some oocytes extruded gigantic polar bodies (>30 m) that later divided into two small ones. Some oocytes underwent symmetric division and produced two equal-size daughter cells in which normal spindles formed. In oocytes with different division patterns, MAP kinase was normally phosphorylated. When the concentration of U0126 was increased to 15 M, the phosphorylation of both MAPK and p90 rsk were inhibited, while symmetric division was decreased. When incubating in medium containing 15 M U0126 for 14 h, oocytes were activated, but part of them failed to emit polar bodies. MII oocytes were also activated by 15 M U0126, at the same time the dephosphorylation of MAP kinase and p90 rsk was observed. Our results indicate that 1) MEK plays important but not indispensable roles in microtubule organization; 2) MEK keeps normal meiotic spindle morphology, targets peripheral spindle positioning and regulates asymmetric division by activating some unknown substrates other than MAP kinase /p90 rsk ; and 3) activation of MEK/ERK/p90 rsk cascade maintains MII arrest in mouse oocytes.

Cu is a promising electrocatalyst in CO 2 reduction reaction (CO 2 RR) to high-value C 2+ products. However, as important C−C coupling active sites, the Cu + species is usually unstable under reduction conditions. How atomic dopants affect the performance of Cu-based catalysts is interesting to be studied. Herein, we first calculated the difference between the thermodynamic limiting potentials of CO 2 RR and the hydrogen evolution reaction, as well as the *CO binding energy over Cu 2 O doped with different metals, and the results indicated that doping atomic Gd into Cu 2 O could improve the performance of the catalyst effectively. On the basis of the theoretical study, we designed Gd 1 / CuO x catalysts. The distinctive electronic structure and large ion radii of Gd not only keep the Cu + species stable during the reaction but also induce tensile strain in Gd 1 /CuO x , resulting in excellent performance of the catalysts for electroreduction of CO 2 to C 2+ products. The Faradic efficiency of C 2+ products could reach 81.4% with a C 2+ product partial current density of 444.3 mA cm −2 at −0.8 V vs a reversible hydrogen electrode. Detailed experimental and theoretical studies revealed that Gd doping enhanced CO 2 activation on the catalyst, stabilized the key intermediate O*CCO, and reduced the energy barrier of the C−C coupling reaction.

Chitosan hydrogels were prepared and imprinted by Ag I with different mass ratios. Compared with the native chitosan hydrogel sample, the optimally imprinted sample (Agim75) presents a significantly enhanced Ag I adsorption capacity as well as a high selectivity. This is attributed to the specific cavities formed by the template Ag I ions in the polymer matrix. The effect of the adsorption conditions and desorption process were also studied.

Developing electrocatalytic reactions with high-efficiency can make important contributions to carbon neutrality. However, poor long-term stability of catalysts is a bottleneck for its practical application. Herein, an "in situ periodic regeneration of catalyst (PR-C)" strategy is proposed to give long-term high efficiency of CO 2 electroreduction to generate C 2 + products over Cu catalyst by applying a positive potential pulse for a short time periodically in the halide-containing electrolyte. The high Faradaic efficiency (81.2 %) and current density (22.6 mA cm À 2 ) could be maintained completely at least 36 h, while the activity and selectivity decreased continuously without using the PR-C method. Control experiments and operando characterization demonstrated that the surface structure and oxidation state of Cu could be recovered periodically by the PR-C method, which was beneficial for CO 2 activation and CÀ C coupling.