Highly Efficient, Selective, and Stable CO2 Electroreduction on a Hexagonal Zn Catalyst.

Electrocatalytic CO2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H2 evolution during CO2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO2 to CO by more effectively stabilizing a (.) COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst.

Fusion rates of instrumented lumbar spinal arthrodesis according to surgical approach: a systematic review of randomized trials.

BACKGROUND: Lumbar spine fusion rates can vary according to the surgical technique. Although many studies on spinal fusion have been conducted and reported, the heterogeneity of the study designs and data handling make it difficult to identify which approach yields the highest fusion rate. This paper reviews studies that compared the lumbosacral fusion rates achieved with different surgical techniques. METHODS: Relevant randomized trials comparing the fusion rates of different surgical approaches for instrumented lumbosacral spinal fusion surgery were identified through highly sensitive and targeted keyword search strategies. A methodological quality assessment was performed according to the checklist suggested by the Cochrane Collaboration Back Review Group. Qualitative analysis was performed. RESULTS: A literature search identified six randomized controlled trials (RCTs) comparing the fusion rates of different surgical approaches. One trial compared anterior lumbar interbody fusion (ALIF) plus adjunctive posterior transpedicular instrumentation with circumferential fusion and posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF). Three studies compared PLF with circumferential fusion. One study compared three fusion approaches: PLF, PLIF and circumferential fusion. CONCLUSIONS: One low quality RCT reported no difference in fusion rate between ALIF with posterior transpedicular instrumentation and circumferential fusion, and PLIF and circumferential fusion. There is moderate evidence suggesting no difference in fusion rate between PLF and PLIF. The evidence on the fusion rate of circumferential fusion compared to PLF from qualitative analysis was conflicting. However, no general conclusion could be made due to the scarcity of data, heterogeneity of the trials included, and some methodological defects of the six studies reviewed.

1,2,3,6-tetra-O-galloyl-beta-D-allopyranose gallotannin isolated, from Euphorbia jolkini, attenuates LPS-induced nitric oxide production in macrophages.

Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including vasodilatation and macrophage-mediated immunity. Macrophages express inducible NO synthase (iNOS) and produce NO after lipopolysaccharide (LPS) stimulation. Gallotannins are water-soluble polyphenols with wide-ranging biological activities. Various chemical structures of gallotannins occurring in medicinal and food plants that are used worldwide showed several remarkable biological and pharmacological activities. In the present study, we examined the inhibitory effects of gallotannin 1,2,3,6-tetra-O-galloyl-beta-D-allopyranose (GT24) isolated from Euphorbia jolkini on the LPS-induced NO production and underlying mechanisms of action. GT24 dose-dependently decreased LPS-induced NO production and iNOS expression in J774A.1 macrophages. In addition, GT24 inhibited LPS-induced activation of nuclear factor (NF)-kappaB as indicated by inhibition of degradation of I-kappaBalpha, nuclear translocation of NF-kappaB, and NF-kappaB dependent gene reporter assay. Our results suggest that GT24 possesses an inhibitory effect on the LPS-induced inflammatory reaction.

Hepatoprotective effect of pinoresinol on carbon tetrachloride-induced hepatic damage in mice.

Forsythiae Fructus is known to have diuretic, anti-bacterial, and anti-inflammatory activities. This study examined the hepatoprotective effects of pinoresinol, a lignan isolated from Forsythiae Fructus, against carbon tetrachloride (CCl(4))-induced liver injury. Mice were treated intraperitoneally with vehicle or pinoresinol (25, 50, 100, and 200 mg/kg) 30 min before and 2 h after CCl4 (20 microl/kg) injection. In the vehicle-treated CCl(4 )group, serum aminotransferase activities were significantly increased 24 h after CCl4 injection, and these increases were attenuated by pinoresinol at all doses. Hepatic glutathione contents were significantly decreased and lipid peroxidation was increased after CCl4 treatment. These changes were attenuated by 50 and 100 mg/kg of pinoresinol. The levels of protein and mRNA expression of inflammatory mediators, including tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2, were significantly increased after CCl4 injection; and these increases were attenuated by pinoresinol. Nuclear translocation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of c-Jun, one of the components of activating protein 1 (AP-1), were inhibited by pinoresinol. Our results suggest that pinoresinol ameliorates CCl4)-induced acute liver injury, and this protection is likely due to anti-oxidative activity and down-regulation of inflammatory mediators through inhibition of NF-kappaB and AP-1.

Hydrogen peroxide-induced alterations of tight junction proteins in bovine brain microvascular endothelial cells.

Occludin and zonular occludens (ZO)-1 in tight junctions (TJs) and actin play an important role in maintaining blood-brain barrier (BBB) endothelial ion and solute barriers. Malfunction of BBB by reactive oxygen species (ROS) has been attributed to the disruption of TJs. This study examined H2O2 effects on changes of paracellular permeability, actin, and TJ proteins (occludin and ZO-1) using primary culture of bovine brain microvessel endothelial cells. The BBB permeability, measured as transendothelial electrical resistance (TER), decreased in a dose- and time-dependent manner when treated with H2O2. Cytotoxicity test revealed that H2O2 did not cause cell death at 0.01, 0.1, and 1.0 mM H2O2. H2O2 caused increased protein expression of occludin (1.17- to 1.29-fold) and actin (1.2- to 1.3-fold). ZO-1 maintained steady state levels of expression. H2O2 caused rearrangement of occludin and ZO-1 at tight junctions and formation of actin stress fiber. Although ZO-1 did not show significant change in protein expression, permeability changes shown in the current study correlate with alterations in expression and localization of occludin, actin, and ZO-1. These data suggest that H2O2 induces increased paracellular permeability of BBB that is accompanied with redistribution of occludin and ZO-1 and increased protein expression of occludin and actin.