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In this study, the effect of nickel content in two kinds of supermartensitic stainless steels, the new composition SMSS + Ni and already known SMSS–Ni, is compared concerning their mechanical properties as a function of tempering temperatures. The SMSS + Ni showed a microstructure composed of well-distributed thin martensite within austenite. In contrast, in the SMSS–Ni, there was much less austenite, and martensite was thicker, thus exposing it more to the environment. Therefore, one observed that the thinner the martensite, the higher the hardness and tensile stresses, and the lower the ductility. Overall, tempered samples at 620 °C presented better toughness. Therefore, the weldability of the steel SMSS + Ni was also analyzed in this tempering temperature condition, presenting excellent welding performance. However, after welding, there was an increase in austenite and thickening of martensite laths in the heat-affected zone (HAZ), leading to its poor distribution within austenite. Corrosion properties were studied comparing both kinds of steels tempered at 620 °C, which was also performed in the steel SMSS + Ni in the welded condition. It was observed that the better the distribution of martensite, the better the corrosion properties. The pitting potential for the SMSS + Ni was the lowest; its polarization curve was positioned in a nobler region, with lower corrosion potential and corrosion current density than these for the SMSS–Ni and in its welded condition. [ABSTRACT FROM AUTHOR]

Non-coding (nc)RNAs are key players in numerous biological processes such as gene regulation, chromatin domain formation and genome stability. Large ncRNAs interact with histone modifiers and are involved in cancer development, X-chromosome inactivation and autosomal gene imprinting. However, despite recent evidence showing that pervasive transcription is more widespread than previously thought, only a few examples mediating gene regulation in eukaryotes have been described. In Saccharomyces cerevisiae, the bona-fide regulatory ncRNAs are destabilized by the Xrn1 5?-3? RNA exonuclease (also known as Kem1), but the genome-wide characterization of the entire regulatory ncRNA family remains elusive. Here, using strand-specific RNA sequencing (RNA-seq), we identify a novel class of 1,658 Xrn1-sensitive unstable transcripts (XUTs) in which 66% are antisense to open reading frames. These transcripts are polyadenylated and RNA polymerase II (RNAPII)-dependent. The majority of XUTs strongly accumulate in lithium-containing media, indicating that they might have a role in adaptive responses to changes in growth conditions. Notably, RNAPII chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) analysis of Xrn1-deficient strains revealed a significant decrease of RNAPII occupancy over 273 genes with antisense XUTs. These genes show an unusual bias for H3K4me3 marks and require the Set1 histone H3 lysine 4 methyl-transferase for silencing. Furthermore, abolishing H3K4me3 triggers the silencing of other genes with antisense XUTs, supporting a model in which H3K4me3 antagonizes antisense ncRNA repressive activity. Our results demonstrate that antisense ncRNA-mediated regulation is a general regulatory pathway for gene expression in S. cerevisiae. [ABSTRACT FROM AUTHOR]

This study has shown that the phenomenon of electrochemical promotion of catalysis or NEMCA effect can be used to activate a metal catalyst for the propene deep oxidation in the presence of water in the feed and in both stoichiometric and lean-burn conditions. The electrochemical catalysts were based on sputtered Pt films interfaced with gadolinium-doped ceria solid electrolyte. This system allows implementing NEMCA effect at quite low temperatures and electrochemical activation of propene deep oxidation was evidenced at temperatures as low as 190 °C. In addition, a new design of electrochemical catalysts was proposed by depositing a interlayer of strontium-doped lanthanum manganite between the CGO dense support and an ultra-thin coating of Pt. This concept allows to drastically decrease the Pt loading since the electronic conductivity is ensured by the perovskite layer. [ABSTRACT FROM AUTHOR]

Electrochemical catalysts based on Pd deposited by Physical Vapour Deposition on YSZ were used for methane deep oxidation. Different thicknesses of Pd films varying from 11 to 75 nm were catalytically characterized between 150 and 750 °C. The Pd loadings were extremely low. Catalytic and EPOC experiments were carried out on those electrochemical catalysts. Their catalytic activities were compared with the performances of a reference catalyst. It was found that the catalytic activity can be in situ tuned by applying an anodic polarization thus supplying oxygen ions at the surface of the catalyst. Faradaic efficiency values up to 258 were observed and the induced modifications of the catalytic rate were typically 100 times higher than the corresponding ionic current. The influence of the polarization on the temperature of decomposition of the palladium oxide was also examined. The polarization was found to enhance the thermal stability of the oxide and turn palladium oxide into metallic palladium at higher temperatures. [ABSTRACT FROM AUTHOR]

Electrochemical catalysts based on LSM deposited on YSZ were used for propane deep oxidation. Electrochemical characterizations such as impedance spectroscopy and current–overpotential measurements were performed. Different thicknesses of LSM films were catalytically characterized and EPOC experiments were carried out on those electrochemical catalysts. It was found that the reaction rates can be in situ tuned by applying an anodic polarization but with weak promotional effects. The faradaic efficiency decreased as the applied potential, the temperature, and the thickness of the catalyst increased. [ABSTRACT FROM AUTHOR]