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Carbon supported gold-iridium composite (AuIr/C) was synthesized by a facile one-step process and was investigated as the bifunctional catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The physical properties of the AuIr/C composite were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Although the Au and Ir in the AuIr/C did not form alloy, it is clear that the introduction of Ir decreases the average Au particle size to 4.2nm compared to that in the Au/C (10.1nm). By systematical analysis on chemical state of metal surface via XPS and the electrochemical results, it was found that the Au surface for the Au/C can be activated by potential cycling from 0.12V to 1.72V, resulting in the increased surface roughness of Au, thus improving the ORR activity. By the same potential cycling, the Ir surface of the Ir/C was irreversibly oxidized, leading to degraded ORR activity but uninfluenced OER activity. For the AuIr/C, Ir protects Au against being oxidized due to the lower electronegativity of Ir. Combining the advantages of Au and Ir in catalyzing ORR and OER, the AuIr/C catalyst displays an enhanced catalytic activity to the ORR and a comparable OER activity. In the 50-cycle accelerated aging test for the ORR and OER, the AuIr/C displayed a satisfied stability, suggesting that the AuIr/C catalyst is a potential bifunctional catalyst for the oxygen electrode.

Three-dimensional nanoporous metals of highly porous structure and interconnected ligaments are attractive for electrochemical reactions. Herein, freestanding 3D nanoporous silver (np-Ag) is prepared by a facile electrochemical approach, i.e., first electro-oxidizing silver to silver halides followed by electro-reduction of the silver halides by controlling the potential applied to the electrode. The np-Ag displays 130 and 11.5 times enhancement in catalytic activity for the oxygen reduction reaction and the formaldehyde electro-oxidation reaction, respectively, relative to the flat polycrystalline silver, and even outperforms the commercial nano-Pt catalyst. Detailed experimental and theoretical studies discover that both the facilitated mass transportation in the 3D interconnected porous structures and the favored kinetics contribute to the superior electro-catalytic activity of np-Ag.

Several studies have indicated an association between tumor necrosis factor-alpha (TNF-α) or interleukin (IL)-6 gene polymorphisms and lung cancer risk. However, the conclusions remain controversial. An English literature screening about case-control trials with regard to TNF-α (-308G/A) or IL-6 (174G/C) polymorphisms and lung cancer susceptibility was performed on PubMed, EMBASE, and EBSCO until November 2012. The pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated using STATA 11.0. Sensitivity analysis was performed by sequential omission of individual studies. Publication bias was evaluated by Egger’s linear regression test and funnel plots. Eight eligible studies, including 1,690 patients and 1,974 controls, were identified in this meta-analysis. Compared with the control, no significant association was revealed between TNF-α-308G/A (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) or IL-6 174G/C (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) and lung cancer risk. The pooled OR remained unchanged after removing the maximum-weight study and no publication bias was observed. The study raises the possibility of no correlation between the polymorphisms of the two genes and lung cancer susceptibility. However, further researches with large-sample or subgroup analyses are necessary to validate the conclusions.