Preferential oxidation of CO in H2 over highly loaded Au/ZrO2 catalysts obtained by direct oxidation of bulk alloy

The intimate mixture of a skeletal gold structure with ZrO2 nanoparticles obtained simply by oxidation of Au(0.5)Zr(0.5) alloy at room temperature turns out to be an efficient catalyst for the selective oxidation of CO in the presence of hydrogen.     

On Directed Sets and their Suprema

The aim of this paper is to investigate partially ordered real linear topological spaces in which directed sets admit a supremum in their closure. In particular, we point out that this property is intimately related to the normality of the ordering cone and also to the Scott continuity of functionals belonging to the nonnegative polar of the ordering cone. Research of Mohamed Ait Mansour was supported by LACO (Laboratoire d'Arithmétique, Calcul Formel et Optimisation), UMR-CNRS 6090, University of Limoges and Agence Universitaire de la Francophonie.     

Microtubule‐Binding R3 Fragment from Tau Self‐Assembles into Giant Multistranded Amyloid Ribbons

Tau protein and its fragments self‐assemble into amyloid fibrils in the presence of polyanions, such as heparin. By combining microscopy, scattering, and spectroscopy techniques, we studied the aggregation of the 26‐mer Tau‐derived peptide alone, Tau_306–327, the third repeat fragment (R3) of the microtubule‐binding domain. We show that: i) the sole Tau_306–327 can self‐assemble into amyloid fibrils without the need of aggregation‐promoting polyanions; ii) the resulting structures consist of surprisingly large, well‐ordered 2D laminated flat ribbons, with a log‐normal distribution of the lateral width, reaching the unprecedented lateral size of 350 nm and/or 45 individual protofilaments, that is, the largest amyloid laminated structures ever observed for Tau or any other amyloidogenic sequence. Our results provide insight into the molecular determinants of Tau aggregation and open new perspectives in the understanding of the assembly of amyloid fibrils and β‐sheet‐based biomaterials.     

Chemical composition, antibacterial and antioxidant activities of the essential oils from Thymus satureioides and Thymus pallidus

This study was designed to examine the in vitro antibacterial and antioxidant activities of the essential oils (EOs) of Thymus satureioides (T.s) and T. pallidus (T.p). EOs were isolated by steam distillation and analyzed by capillary gas chromatography and gas chromatography coupled to mass spectrometry (GC-MS). The major constituents of the volatile fraction of T. satureioides were bomeol (29.5%), carvacrol (9.1%), and beta-caryophyllene (8.2%), while those of T. pallidus were camphor (29.8%), dihydrocarvone (17.6%), bomeol (7.6%) and camphene (7.5%). The essential oils were tested against a panel of Gram+ and Gram- bacteria by using agar diffusion and broth dilution methods. The data indicated that the Gram-positive Bacillus subtilis was the most sensitive strain producing an average inhibition zone of 51.7 mm. Furthermore, Pseudomonas aeruginosa, known as a resistant strain, was also sensitive. The samples were also subjected to screening for their possible antioxidant activity by using the 2,2-diphenyl-l-picrylhydrazyl (DPPH) assay. The IC50 values of the oil of T. satureioides and T. pallidus were 0.32 and 11.6 mg/mL, respectively.     

Phase equilibrium properties of binary aqueous solutions of benzylamine, 1,2-bis(2-aminoethoxy)ethane,or 2-[2-(dimethylamino)ethoxy]ethanol

The vapour pressures of (benzylamine + water), {1,2-bis(2-aminoethoxy)ethane + water}, or {2-[2-(dimethylamino)ethoxy]ethanol + water} binary mixtures, and pure 2-[2-(dimethylamino)ethoxy]ethanol component were measured by means of two static devices at temperatures between (283.15 and 363.15 (or 323.15)) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The (benzylamine + water) binary mixture exhibits positive deviations in G^E for (303.15 < T/K < 323.15) and a sinusoidal shape in G^E for T > 323.15 K over the whole composition range. The aqueous 1,2-bis(2-aminoethoxy)ethane or {2-[2-(dimethylamino)ethoxy]ethanol + water} solutions exhibit negative deviations in G^E for all investigated temperatures over the whole composition range.     

Modelling and analysis of a non-regular electronic circuit via a variational inequality formulation

In this paper, we present a new and alternative mathematical modelling and analysis methodology for a class of non-regular electronic circuits through a rectifier-stabilizer circuit using the superpotentiel of Moreau and the theory of variational inequalities. This methodology is suitable for engineers to study a large class of applications.     

Highly Diastereoselective Synthesis of Functionalized β-Lactams

An efficient method based, on the acid chloride-imine reaction, is reported for the preparation of 1,3-disubstituted β-lactams in good yield and with high selectivity.