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The as-rolled K41X (AISI 441) ferritic stainless steel presents unusual behaviour when exposed in H 2 –H 2 O atmosphere at 800 °C, with growth of non-protective iron oxides at its surface. The impact of pre-oxidation in air is investigated in this paper. The pre-oxidation induces the formation of a thin chromia layer at the steel surface. The results obtained after subsequent oxidation for 100 h in H 2 –H 2 O atmosphere evidence a change in the surface reactivity behaviour of the as-rolled alloy: iron oxides formation is avoided and high temperature behaviour (reactivity and conductivity) is improved. Air pre-oxidation seems a promising solution for large scale use of K41X as-rolled steel in H 2 –H 2 O atmosphere at high temperature. • Pre-oxidation impact on high temperature behaviour of an as-rolled steel is studied. • Pre-oxidation leads to the formation of a thin chromia layer at the steel surface. • After subsequent oxidation in H 2 –H 2 O atmosphere iron oxides formation is avoided. • High temperature reactivity and conductivity of as-rolled steel are improved. • Pre-oxidation represents a large-scale alternative to the mirror polishing process. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The K41X alloy was surface-modified via the application of coatings. • La 0.8 Sr 0.2 MnO 3 , LaNi 0.6 Fe 0.4 O 3 , Co 2 MnO 4 and Co 3 O 4 were chosen as coatings. • Isothermal oxidation tests were performed up to 3000 h at 800 °C in H 2 -H 2 O. • Fe-rich oxides growth was avoided and a protective (Cr,Mn) 3 O 4 /Cr 2 O 3 scale formed. • All coatings were efficient in preventing from Cr evaporation up to 3000 h ageing. Abstract In order to improve the oxidation behaviour of AISI441 ferritic stainless steel in H 2 /H 2 O atmosphere at 800 °C, four oxide coatings were tested: two perovskites (La 0.8 Sr 0.2 MnO 3 and LaNi 0.6 Fe 0.4 O 3) deposited by screen printing and two spinels (MnCo 2 O 4 and Co 3 O 4) obtained by PVD technique. Isothermal oxidation tests performed up to 3000 h showed that the coating presence avoided Fe oxides growth, which occurs for the raw alloy in the same conditions. Moreover, a protective (Cr,Mn) 3 O 4 /Cr 2 O 3 layer formed between the substrate and the coating. Any presence of Cr was not detected within the coatings, indicating that all compositions were efficient in preventing Cr evaporation. [ABSTRACT FROM AUTHOR]

High temperature water vapour electrolysis (HTE) is one of the most efficient technologies for mass hydrogen production. A major technical difficulty related to high temperature water vapour electrolysis is the development of interconnects working efficiently for a long period. Working temperature of 800 °C enables the use of metallic materials as interconnects. High temperature corrosion behaviour and electrical conductivity of a commercial stainless steel, K41X (AISI 441), were tested in HTE dual atmosphere (95%O 2 -5%H 2 0/10%H 2 -90%H 2 O) at 800 °C. The alloy exhibits a very good oxidation resistance compared to single atmosphere tests. However, a supplied electrical current significantly changes the nature of the oxides that form during the test. A very good Area Specific Resistance (ASR) parameter was measured in dual atmosphere, much lower than the values obtained in single atmosphere tests. [ABSTRACT FROM AUTHOR]

K41X (AISI 441) stainless steel evidenced a high electrical conductivity after 3000 h ageing in H 2 /H 2 O side when used as interconnect for solid oxide electrolyser cells (SOEC) working at 800 °C. Perovskite (La 1 − x Sr x MnO 3 − δ ) and spinel (Co 3 O 4 ) oxides coatings were applied on the surface of the ferritic steel for ageing at 800 °C for 3000 h. Both coatings improved the behaviour of the steel and give interesting opportunities to use the K41X steel as interconnect for hydrogen production via high temperature steam electrolysis. Co 3 O 4 reduced into Co leading to a very good Area Specific Resistance (ASR) parameter, 0.038 Ω cm 2 . Despite a good ASR (0.06 Ω cm 2 ), La 1 − x Sr x MnO 3 − δ was less promising because it partially decomposed into MnO and La 2 O 3 during ageing in H 2 /H 2 O atmosphere. [ABSTRACT FROM AUTHOR]

Abstract: High temperature water vapour electrolysis (HTE) is an efficient technology for hydrogen production. In this context, a commercial stainless steel, K41X (AISI 441), was chosen as interconnect. In a previous paper, the high temperature corrosion and the electrical conductivity were evaluated in both anode (O2–H2O) and cathode (H2–H2O) atmosphere at 800 °C. In O2–H2O atmosphere, the formation of a thin chromia protective layer was observed. Nevertheless, the ASR parameter measured was higher than the maximum accepted value. These results, in addition with chromium evaporation measurements, proved that the K41X alloy is not suitable for HTE interconnect application. In this study, two perovskite-type oxides La0.8Sr0.2MnO3−δ and LaNi0.6Fe0.4O3−δ were tested as coatings in O2–H2O atmosphere at 800 °C. Screen-printing and physical vapour deposition were used as coating processes. The high temperature corrosion resistance and the electrical conductivity were improved, especially with the LaNi0.6Fe0.4O3−δ coating. Cr specie volatility was also reduced. [Copyright &y& Elsevier]

Abstract: For economic and ecological reasons, hydrogen is considered as a major energetic vector for the future. Hydrogen production via high temperature water vapour electrolysis (HTE) is a promising technology. A major technical difficulty related to high temperature water vapour electrolysis is the development of interconnects working efficiently for a long period. Working temperature of 800 °C enables the use of metallic materials as interconnects. High temperature corrosion behaviour and electrical conductivity of a new Cr-free Fe–Ni–Co alloy were tested in cathode atmosphere (H2/H2O) at 800 °C. The alloy exhibits a poor oxidation resistance but an excellent ASR parameter, as a result of the formation of a highly-conductive Cr-free surface spinel layer. Moreover, the role of water vapour and hydrogen was discussed and a diffusion mechanism in cathode atmosphere could be suggested. [Copyright &y& Elsevier]

Abstract: The RFe12−X M X compounds (R=Pr, Nd; M=Ti, V, Cr, Mn, Mo, Nb), known as the 1:12 phases, are interesting as potential permanent magnets due to their high magnetisation level. For example, the NdFe10.5V1.5N y phase present higher intrinsic magnetic properties than the Nd2Fe14B phase when the compound is fully and homogeneously nitrogenated. The in situ neutron diffraction allowed us to identify two different mechanisms for the nitrogenation reaction of NdFe10.5V1.5 samples that can account for the necessary temperature optimisation of the nitrogenation step. Two different behaviours observed on nitrogenation of annealed or HDDR-processed powders also suggest that the starting microstructure of the powder is a key parameter in the nitrogenation process. [Copyright &y& Elsevier]

A2B5 antibody was found to strongly label frozen sections of human head and neck squamous cell carcinomas. The low amount of glycolipids (c-series gangliosides and sulfatides) purified from the same tumors and reactive with A2B5 by immunostaining on thin-layer plates could not account for the high level of tissue labeling. Proteins were extracted from both normal tissues and squamous cell carcinomas and analyzed by Western blot with A2B5 antibody on PVDF membranes. The antibody was found to stain a set of glycoproteins with two major bands at 55 and 76 kDa present in normal tissues and overexpressed in carcinomas. Staining was abolished by prior treatment of the PVDF membranes either with Arthrobacter ureafaciens neuraminidase or with a solution of 10 mM periodate that is known to destroy carbohydrates. Our results show that the carbohydrate epitope recognized by A2B5 antibody can be displayed by both glycolipids and glycoproteins. [Copyright &y& Elsevier]

Ceramides (Cer) are key intermediates in the metabolism of sphingomyelin and are also important second messengers. We report that natural long-chain ceramides added to the incubation medium in microgram amounts are internalized in HL-60 cells as well as the short-chain analogue C2-Cer and targeted to various subcellular compartments. No significant difference was detected in the ability of HL-60 cells to metabolize exogenous Cer containing a short (acetyl) versus long (palmitoyl or oleoyl) acyl chain. After a 2-h incubation time with [14C]-C16 ceramides, most of the cell-bound radioactivity was found in free ceramides. Sphingomyelin was the major metabolized sphingolipid containing labeled ceramides and only a small proportion of exogenous ceramides were converted to neutral glycolipids and gangliosides. Up to 20% of the exogenous ceramides taken up by the cells were recovered in mitochondria, mostly as authentic C16 ceramides and C16 sphingomyelin, along with a trace amount of labeled GM3 ganglioside. These results are consistent with the notion that exogenous natural ceramides enter cells, can be further metabolized in situ and partly targeted to mitochondria, which are known to be involved in the control of programmed cell death. [Copyright &y& Elsevier]

• Oxidation of Ti6242S alloy at 560 °C in air follows a parabolic kinetics law. • Oxide growth and oxygen dissolution kinetics obey to parabolic laws. • Oxide scales are thin and mainly composed of rutile and anatase. • Nitrogen enrichment of a thin layer in the metal. • Oxygen dissolution in the metal results in lattice dilatation. High temperature oxidation of titanium alloy Ti6242S was studied in air at 560 °C up to 10000 h. Oxidation kinetics obeys a parabolic law (k p = 8.7 × 10−15 g². cm−4.s-1). Oxygen dissolution in the metal was found to represent between 80 and 90% of the total mass gain. Thin oxide scales are mainly composed of TiO 2 , in top of which some alumina is present. Titanium nitride was detected as a very thin layer at the outer part of the metallic substrate. Underneath, the oxygen dissolution area was found to reach the maximum brittleness after 1000 h of oxidation. [ABSTRACT FROM AUTHOR]

Gangliosides are glycosphingolipids made of hydrophobic ceramides coupled to hydrophilic sialylated oligosaccharides. They belong to lipid rafts located on the outer leaflet of the plasma membrane and their oligosaccharide moieties are exposed on the cell surface. Gangliosides are shed as monomeric molecules from the plasma membrane by a largely unknown mechanism into the extracellular medium and they are synthesized de novo by the cells. The shed gangliosides bind to lipoproteins from which they are taken up by erythrocytes and leukocytes. The ganglioside enrichment of leukocytes results in an alteration in the transduction of activation signals, leading to an impaired cellular immunity. [Copyright &y& Elsevier]