A mode matching approach for modeling two dimensional porous grating with infinitely rigid or soft inclusions

This work investigates the acoustical properties of a multilayer porous material in which periodic inclusions are embedded. The material is assumed to be backed by a rigid wall. Most of the studies performed in this field used the multipole method and are limited to circular shape inclusions. Here, a mode matching approach, more convenient for a layered system, is adopted. The inclusions can be in the form of rigid scatterers of an arbitrary shape, in the form of an air-filled cavity or in the form of a porous medium with contrasting properties. The computational approach is validated on simple geometries against other numerical schemes and with experimental results obtained in an anechoic room on a rigid grating embedded in a porous material made of 2 mm glass beads. The method is used to study the acoustic absorption behavior of this class of materials in the low frequency range and at a range of angles of incidence.     

Microwave-assisted solid-phase synthesis of 5-carboxamido-N-acetyltryptamine derivatives

[reaction: see text] The synthesis of the indole skeleton of new melatoninergic analogues was realized using solid-phase methodology in association with microwave irradiation. This combination speeds up the solid-phase drug discovery process in rigorously established conditions.     

Asymmetric Hydroxylative Phenol Dearomatization through In Situ Generation of Iodanes from Chiral Iodoarenes and m‐CPBA

′I′ is all the hype : A twofold excess of iodoarene in the title reaction leads to ortho‐quinols in good yields, whereas organocatalytic versions of this reaction enable subsequent epoxidation in a regio‐ and diastereoselective fashion. Chiral iodobiarenes led to enantioselectivities up to 50 % ee. m‐CPBA=meta‐chloroperoxybenzoic acid.

     

The AZARYPHOS Family of Ligands for Ambifunctional Catalysis: Syntheses and Use in Ruthenium‐Catalyzed anti‐Markovnikov Hydration of Terminal Alkynes

The family of AZARYPHOS (aza–aryl–phosphane) phosphane ligands, containing a phosphine unit and sterically shielded nitrogen lone pairs in the ligand periphery, is introduced as a tool for developing ambifunctional catalysis by the metal center and nitrogen lone pairs in the ligand sphere. General synthetic strategies have been developed to synthesize over 25 examples of structurally diverse (6‐aryl‐2‐pyridyl)phosphanes (ARPYPHOS), (6‐alkyl‐2‐pyridyl)phosphanes (ALPYPHOS), 4,6‐disubsituted 1,3‐diazin‐2‐ylphosphanes or 1,3,5‐triazin‐2‐ylphosphanes, quinazolinylphosphanes, quinolinylphosphanes, and others. The scalable syntheses proceed in a few steps. The incorporation of AZARYPHOS ligands ( L ) into complexes [RuCp( L )₂(MeCN)][PF₆] (Cp=cyclopentadienyl) gives catalysts for the anti‐Markovnikov hydration of terminal alkynes of the highest known activities. Electronic and steric ligand effects modulate the reaction kinetics over a range of two orders of magnitude. These results highlight the importance of using structurally diverse ligand families in the process of developing cooperative ambifunctional catalysis by a metal and its ligand.     

Poly(oxyalkylene) synthesis in Brønsted acid ionic liquids

The polyetherification of diols with 4-12 methylene units was studied in Br?nsted Acid Ionic Liquids (BAILs). High molar mass poly(oxyalkylene)s were obtained at relatively low temperatures (130 °C), except in the cases of 1,4-butanediol and 1,6-hexanediol where cyclic ether formation was observed.     

Identification of selenium in the leaf protein of sunflowers by a combination of 2D-PAGE and laser ablation ICP-MS

We report on a method for the identification of selenium-containing proteins in an extract of sunflower leafs. It is based on the separation of the proteins by 2-dimensional gel electrophoresis, followed by detection of selenium via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The laser system was operated in a raster mode at 100?μm?s^-1 and proved to be an efficient alternative in the search for selenoproteins in the spots of the gels. The instrumental parameters were optimized in terms of plasma energy and application of optimal reaction cell conditions, and the detection of the mass ⁸⁰Se¹⁶O⁺ which enabled the elimination of interfering species. Selenium was identified in 9.6% of the analyzed spots, indicating its random incorporation into the primary structure of the proteins.

Fluorescent Groups at the Core of Phosphorus Dendrons and Their Properties

This review presents the synthesis of dendrons (dendritic wedges) based on cyclotriphosphazene cores, in which one function is a fluorescent group, and the five remaining functions are used for growing the dendritic branches. The growing of the branches is carried out by a divergent method, using a two-step process which implies hydroxybenzaldehyde and the phosphorhydrazide H₂NNMeP(S)Cl₂. Four different fluorophores have been used, derived from maleimide, julolidine, pyrene, or from a near-infra-red fluorophore. Depending on the type of fluorophore and on the type of terminal functions of the dendrons, different applications have been targeted. One can cite experiments in catalysis or for the elaboration of materials, transfection experiments, the study of anti-cancer properties, and imaging in relation with the human immune system.     

Thom property and Milnor–Lê fibration for analytic maps

Let (X, 0) be the germ of either a subanalytic set $X\subset {\mathbb{R}}^n$ or a complex analytic space $X\subset {\mathbb{C}}^n$, and let $f:(X,0)\to ({\mathbb{K}}^k,0)$ be a $\mathbb{K}$-analytic map-germ, with $\mathbb{K}=\mathbb{R}$ or $\mathbb{C}$, respectively. When $k=1$, there is a well-known topological locally trivial fibration associated with f, called the Milnor–Lê fibration of f, which is one of the main pillars in the study of singularities of maps and spaces. However, when $k>1$ that is not always the case. In this paper, we give conditions which guarantee that the image of f is well-defined as a set-germ, and that f admits a Milnor–Lê fibration. We also give conditions for f to have the Thom property. Finally, we apply our results to mixed function-germs of type $f\overline{g}:(X,0)\to (\mathbb{C},0)$ on a complex analytic surface $X\subset {\mathbb{C}}^n$ with arbitrary singularity.