Highly Selective Photoelectroreduction of Carbon Dioxide to Ethanol over Graphene/Silicon Carbide Composites.

Using sunlight to produce valuable chemicals and fuels from carbon dioxide (CO2 ), i.e., artificial photosynthesis (AP) is a promising strategy to achieve solar energy storage and a negative carbon cycle. However, selective synthesis of C2 compounds with a high CO2 conversion rate remains challenging for current AP technologies. We performed CO2 photoelectroreduction over a graphene/silicon carbide (SiC) catalyst under simulated solar irradiation with ethanol (C2 H5 OH) selectivity of>99 % and a CO2 conversion rate of up to 17.1 mmol gcat -1 h-1 with sustained performance. Experimental and theoretical investigations indicated an optimal interfacial layer to facilitate the transfer of photogenerated electrons from the SiC substrate to the few-layer graphene overlayer, which also favored an efficient CO2 to C2 H5 OH conversion pathway.

Exclusive Formation of Formic Acid from CO2 Electroreduction by a Tunable Pd-Sn Alloy.

Conversion of carbon dioxide (CO2 ) into fuels and chemicals by electroreduction has attracted significant interest, although it suffers from a large overpotential and low selectivity. A Pd-Sn alloy electrocatalyst was developed for the exclusive conversion of CO2 into formic acid in an aqueous solution. This catalyst showed a nearly perfect faradaic efficiency toward formic acid formation at the very low overpotential of -0.26 V, where both CO formation and hydrogen evolution were completely suppressed. Density functional theory (DFT) calculations suggested that the formation of the key reaction intermediate HCOO* as well as the product formic acid was the most favorable over the Pd-Sn alloy catalyst surface with an atomic composition of PdSnO2 , consistent with experiments.

Structural characterization and improves cognitive disorder in ageing mice of a glucomannan from Dendrobium huoshanense.

In the present work, a neutral polysaccharide (DHP-2W) with attenuating cognitive disorder was identified from Dendrobium huoshanense and its structure was clarified. The polysaccharide was successfully purified from D. huoshanense by column chromatography and its activity was evaluated. With a molecular weight of 508.934kDa, this polysaccharide is composed of mannose and glucose at a molar ratio of 75.81: 24.19. Structural characterization revealed that DHP-2W has a backbone consisting of 4)-ß-D-Manp-(1 and 4)-ß-D-Glcp-(1. In vivo experiments revealed that DHP-2W improved cognitive disorder in D-galactose treated mice and relieved oxidative stress and inflammation. DHP-2W attenuates D-galactose-induced cognitive disorder by inhibiting the BCL2/BAX/CASP3 pathway and activating the AMPK/SIRT pathway, thereby inhibiting apoptosis. Furthermore, DHP-2W had a significant effect on regulating the serum levels of Flavin adenine dinucleotide, Shikimic acid, and Kynurenic acid in aged mice. These, in turn, had a positive impact on AMPK/SIRT1 and BCL2/BAX/CASP3, resulting in protective effects against cognitive disorder.

Design of a Self-Aligning Four-Finger Exoskeleton for Finger Abduction/Adduction and Flexion/Extension Motion.

For wearable four-finger exoskeletons, it is still a challenge to design the metacarpophalangeal (MCP)joint abduction/adduction (a/a) kinematic chain and achieve axes self-aligning. This paper proposes a novel exoskeleton for four fingers that features a high degree of dexterity enabling MCP joint flexion/extension (f/e) and a/a motion. Other features of the exoskeleton include a self-aligning mechanism that absorbs misalignment between the exoskeleton and human joints, the ability to accommodate fingers of different sizes, and a compact design that allows simultaneous a/a motion without interference. This paper presents the exoskeleton's kinematic model, optimizes the range of motion (ROM), and length of the exoskeleton linkage using the Genetic Algorithm. We compare the four-finger MCP joint's ROM and fingertip workspace with and without the exoskeleton. Our experiments show that the proposed exoskeleton has no significant impact on the natural ROM of the four-finger MCP joint, enables the fingers to cover an average of 82.96% of the original workspace, and can reach a significant portion of the fingertip workspace.