Composite Anion Exchange Membranes Fabricated by Coating and UV Crosslinking of Low-Cost Precursors Tested in a Redox Flow Battery.

This paper presents a novel, cost-effective approach to the fabrication of composite anion exchange membranes (AEMs) Hierarchical AEMs have been fabricated by coating a porous substrate with an interpenetrating polymer network (IPN) layer where poly(vinylpyrrolidone) (PVP) is immobilized in a crosslinked matrix. The IPN matrix was formed by UV initiated radical crosslinking of a mixture of acrylamide-based monomers and acrylic resins. The fabricated membranes have been compared with a commercial material (Fumatech FAP 450) in terms of ionic transport properties and performance in a vanadium redox flow battery (VRFB).

Composite Anion-Exchange Membrane Fabricated by UV Cross-Linking Vinyl Imidazolium Poly(Phenylene Oxide) with Polyacrylamides and Their Testing for Use in Redox Flow Batteries.

Composite anion-exchange membranes (AEMs) consisting of a porous substrate and a vinyl imidazolium poly(phenylene oxide) (VIMPPO)/acrylamide copolymer layer were fabricated in a straightforward process, for use in redox flow batteries. The porous substrate was coated with a mixture of VIMPPO and acrylamide monomers, then subsequently exposed to UV irradiation, in order to obtain a radically cured ion-exchange coating. Combining VIMPPO with low-value reagents allowed to significantly reduce the amount of synthesized ionomer used to fabricate the mem- brane down to 15%.

Synthesis of isochroman-4-ones and 2H-pyran-3(6H)-ones by gold-catalyzed oxidative cycloalkoxylation of alkynes.

Gold catalysis is a convenient tool to oxidatively functionalize alkyne into a range of valuable compounds. In this article, we report a new access to isochroman-4-one and 2H-pyran-3(6H)-one derivatives that involves a gold-catalyzed oxidative cycloalkoxylation of an alkyne in the presence of a pyridine N-oxide. The reaction proceeds under mild conditions, is relatively efficient and exhibits a high functional group compatibility.

Surface Charge at the Oxide/Electrolyte Interface: Toward Optimization of Electrolyte Composition for Treatment of Aluminum and Magnesium by Plasma Electrolytic Oxidation.

Controlling microdischarges in plasma electrolytic oxidation is of great importance in order to optimize coating quality. The present study highlights the relationship between the polarity at which breakdown occurs and the electrolyte pH as compared with the isoelectric point (IEP). It is found that working at a pH higher than the IEP of the grown oxide prevents the buildup of detrimental cathodic discharges.

Divergent product selectivity in gold- versus silver-catalyzed reaction of 2-propynyloxy-6-fluoropyridines with arylamines.

A study of the reaction of easily accessible 2-propynyloxy-6-fluoropyridines with arylamines under gold or silver catalysis is described. It has been shown that two types of isomeric oxazolopyridine imine derivatives, which represent unusual heterocyclic motifs, can be selectively obtained in moderate to excellent yields depending on the nature of the metal employed.

Gold-catalyzed synthesis of functionalized pyridines by using 2H-azirines as synthetic equivalents of alkenyl nitrenes.

2H-Azirines are easily synthesized from the corresponding ketones and, despite possessing a CN bond embedded in a strained three-membered cycle, they are sufficiently stable to be isolated, stored, and manipulated. 2H-Azirines can be regarded as valuable synthetic equivalents of alkenyl nitrenes, however, reactions capitalizing on the cyclic strain of the heterocyclic motif and involving the cleavage of the CN single bond remain surprisingly limited. A gold-catalyzed reaction that allows the formation of polysubstituted functionalized pyridines from easily accessible 2-propargyl 2H-azirine derivatives was developed.

Dynamics of bubbles created by plasma in heptane for micro-gap conditions.

The determination of the initial pressure at the bubble wall created by a discharge in heptane for micro-gap conditions cannot be determined straightforwardly by modeling the time-oscillations of the bubble. The resolution of the Gilmore equation gives the same solutions beyond 1 μs typically for various sets of initial parameters, making impossible the determination of the initial pressure at the bubble wall. Furthermore, the very first instant of the bubble formation is not easily accessible at very short time scales because of the plasma emission.

Effects of Ar-H2-N2 microwave plasma on chitosan and its nanoliposomes blend thin films designed for tissue engineering applications.

This work addresses the functionalization of chitosan thin films and its nanoliposomes blend films by a microwave-excited Ar/N2/H2 surface-wave plasma treatment which was found an effective tool to modify surface properties. Changes in the film properties (wettability, chemical composition, morphology) induced by the plasma treatment are studied using water contact angle measurements, X-ray photoelectron spectroscopy and scanning probe microscopy. The results suggest that hydrophilicity of the films is improved by plasma treatment in a plasma condition dependency manner.

Reactive force field potential for carbon deposition on silicon surfaces.

In this paper a new interatomic potential based on the Kieffer force field and designed to perform molecular dynamics (MD) simulations of carbon deposition on silicon surfaces is implemented. This potential is a third-order reactive force field that includes a dynamic charge transfer and allows for the formation and breaking of bonds. The parameters for Si-C and C-C interactions are optimized using a genetic algorithm.

Preliminary analysis of the pandemic H1N1 influenza on Reunion Island (Indian Ocean): surveillance trends (July to mid-September 2009).

First infections with the 2009 pandemic H1N1 influenza virus were identified on Reunion Island in July 2009. By the end of July, sustained community transmission of the virus was established. Pandemic H1N1 influenza activity peaked during week 35 (24 to 30 August), five weeks after the beginning of the epidemic and has been declining since week 36.

Cortex, a Drosophila gene required to complete oocyte meiosis, is a member of the Cdc20/fizzy protein family.

Mutations in cortex and grauzone cause abnormal arrest in Drosophila female meiosis. cortex was mapped to a 14 kb interval in 26F-27A by the male recombination mapping method. While these experiments mapped the gene accurately, they also illustrated some complexities of this method.

Onset of zygotic transcription and maternal transcript legacy in the rabbit embryo.

Onset of zygotic transcription is progressive from the one-cell stage onward in the rabbit embryo. Maternal transcripts remain fairly stable until the 8-16 cell stage when major transcriptional activation of the zygotic genome takes place. To understand the mechanisms of the maternal-to-zygotic transition in the genetic information governing development, we asked whether a progressive synthesis of zygotic transcripts takes over the maternal molecules, or whether the synthesis of zygotic transcripts is very abrupt and independent of the persistence of the maternal counterparts.

The only function of Grauzone required for Drosophila oocyte meiosis is transcriptional activation of the cortex gene.

The grauzone and cortex genes are required for the completion of meiosis in Drosophila oocytes. The grauzone gene encodes a C2H2-type zinc-finger transcription factor that binds to the cortex promoter and is necessary for high-level activation of cortex transcription. Here we define the region of the cortex promoter to which Grauzone binds and show that the binding occurs through the C-terminal, zinc-finger-rich region of the protein.

Differential regulation of the translation and the stability of two maternal transcripts in preimplantation rabbit embryos.

In most species, transcription is essentially silent during the first mitotic cell cycles that follow fertilization. This means that the regulation of gene expression in early embryos heavily relies on the translational activation or inactivation of maternal mRNAs. In mammals, the mechanisms that control the translation of maternal mRNAs have been mainly studied in the mouse when maternal to zygotic transition occurs after the first mitotic division.

Completion of meiosis in Drosophila oocytes requires transcriptional control by grauzone, a new zinc finger protein.

Mutations in grauzone or cortex cause abnormal arrest in Drosophila female meiosis. We cloned grauzone and identified it as a C2H2-type zinc finger transcription factor. The grauzone transcript is present in ovaries and at later developmental stages.

Road accident statistics: discrepancies between police and hospital data in a French island.

In most developed countries, information on road crashes are routinely collected by the police. However, comparison of police records and hospital data underlines a deficit of the number of road accidents in the routine statistics. In La Réunion, a French overseas dependency, an epidemiological study of injuries leading to hospitalisation or deaths has been performed from June 1993 to June 1994.

Identification of maternal transcripts that progressively disappear during the cleavage period of rabbit embryos.

In order to characterize the changes that occur in the population of maternally inherited transcripts before the transition from maternal to zygotic control of embryonic development (MZT) in mammals, we used rabbit embryos where zygotic transcription becomes necessary only after the fourth cleavage division, during the second day that follows fertilization. In the present work we have associated mRNA differential display and an RT-PCR based-method that allows amplification of the whole population of messengers to identify and characterize maternal transcripts which are degraded throughout this early period of development. While there is no major degradation of the polyA RNA population before MZT we identify 4 transcripts which progressively disappear up until the 8-16 cell stage.

[Simultaneous determination of the toxicologically relevant elements: lead, cadmium, and nickel with graphite furnace atomic absorption spectrometry].

A new generation of graphite furnace atomic absorption spectrometer enables the simultaneous determination of several trace elements. Using an optimized temperature-time-program for ashing and atomization, the Smith-Hieftje background correction and a matrix modifier, the determination of Pb, Cd and Ni in one run is possible. The detection limits of the new method of 0,039 mg Pb, 0,006 mg Cd and 0,022 mg Ni per kg sample, permit the determination of these elements in soils, foodstuffs and human food.