Influence of Carbon Dioxide and Humidity on the Stability of (La0.6Sr0.4)0.99Co1−xTixO3−δ Cathode

(La0.6Sr0.4)0.99CoO3−δ is a very promising cathode material due to its excellent electronic and ionic conductivity. However, when using non-artificial air from the ambient atmosphere, it contains impurities such as H2O and CO2. These chemicals cause degradation and performance loss of the cathode. Introduction of Ti into the B-site of (La0.6Sr0.4)0.99CoO3−δ improves the chemical stability of this material. (La0.6Sr0.4)0.99Co1−xTixO3−δ (0 ≤ x ≥ 0.1) electrodes prepared in this work were analyzed using X-ray diffraction method (XRD), X-ray photoelectron spectroscopy (XPS), and with electrochemical impedance spectroscopy (EIS). Studied (La0.6Sr0.4)0.99CoO3−δ materials with Ti in B-site showed reversible degradation under gas mixture with carbon dioxide addition. Under gas mixture with water addition, improved stability was observed for (La0.6Sr0.4)0.99Co1−xTixO3−δ materials with Ti in B-site compared to unmodified (La0.6Sr0.4)0.99CoO3−δ.

β-Glucan phosphorylases in carbohydrate synthesis

β-Glucan phosphorylases are carbohydrate-active enzymes that catalyze the reversible degradation of β-linked glucose polymers, with outstanding potential for the biocatalytic bottom-up synthesis of β-glucans as major bioactive compounds. Their preference for sugar phosphates (rather than nucleotide sugars) as donor substrates further underlines their significance for the carbohydrate industry. Presently, they are classified in the glycoside hydrolase families 94, 149, and 161 (www.cazy.org). Since the discovery of β-1,3-oligoglucan phosphorylase in 1963, several other specificities have been reported that differ in linkage type and/or degree of polymerization. Here, we present an overview of the progress that has been made in our understanding of β-glucan and associated β-glucobiose phosphorylases, with a special focus on their application in the synthesis of carbohydrates and related molecules. Key points • Discovery, characteristics, and applications of β-glucan phosphorylases. • β-Glucan phosphorylases in the production of functional carbohydrates.

Auxin-mediated rapid degradation of selective proteins in hippocampal neurons

Genetic manipulation of protein levels is a promising approach to identify the function of a specific protein in living organisms. Previous studies demonstrated that the auxin-inducible degron (AID) strategy provides rapid and reversible degradation of various proteins in fungi and mammalian mitotic cells. In this study, we employed this technology to postmitotic neurons to address whether the AID system could be applied to the nervous system. Using adeno-associated viruses, we simultaneously introduced EGFP fused with an AID tag, and an F-box family protein, TIR1 fromOryza sativa(OsTIR1) into hippocampal neurons. In dissociated hippocampal neurons, EGFP fluorescence signals rapidly decreased when adding a plant hormone, auxin. Further, auxin-induced EGFP degradation was also observed in hippocampal acute slices. Taken together, these results open the door for neuroscientists to manipulate protein expression levels by the AID-system in a temporally-controlled manner.