Ionic liquids: structuration agents in a fluorinated matrix

The use of ionic liquids as functional building blocks based on pyridinium, imidazolium and phosphonium cations to achieve materials combining a structuration at nanoscale with the dramatic mechanical properties of the resulting ionomers has been successfully demonstrated for the first time in a fluorinated matrix.     

Self-assembled naphthalenediimide derivative films for light-assisted electrochemical reduction of oxygen

This naphthalene diimide derivative, DC18, forms highly conjugated semiconducting stacked assemblies over electrodes after electrochemical conditioning. These molecular materials are very efficient towards electrochemical photoreduction of oxygen under visible light.     

Gene delivery with polycationic fullerene hexakis-adducts

Polyplexes prepared from DNA and globular compact polycationic derivatives constructed around a fullerene hexakis-adduct core have shown remarkable gene delivery capabilities.     

An easily accessible Re-based catalyst for the selective conversion of methanol: evidence for an unprecedented active site structure through combined operando techniques

Heterogeneous Re/SiO(2) catalysts prepared using a one pot sol-gel synthesis were found to display high activity in the direct, selective methanol conversion to methylal, which is correlated to an unprecedented rhenium oxide structure.     

Ion-specific weak adsorption of salts and water/octanol transfer free energy of a model amphiphilic hexapeptide

An amphiphilic hexapeptide has been used as a model to quantify how specific ion effects induced by addition of four salts tune the hydrophilic/hydrophobic balance and induce temperature-dependant coacervate formation from aqueous solution. The hexapeptide chosen is present as a dimer with low transfer energy from water to octanol. Taking sodium chloride as the reference state in the Hofmeister scale, we identify water activity effects and therefore measure the free energy of transfer from water to octanol and separately the free energy associated to the adsorption of chaotropic ions or the desorption of kosmotropic ions for the same amphiphilic peptide. These effects have the same order of magnitude: therefore, both energies of solvation as well as transfer into octanol strongly depend on the nature of the electrolytes used to formulate any buffer. Model peptides could be used on separation processes based on criteria linked to "Hofmeister" but different from volume and valency.     

Experimental study of the draw resonance in fiber spinning

An experimental fiber-spinning device has been built in order to study the draw-resonance phenomenon in nearly isothermal conditions. The influence of the output rate, of the take-up speed and of the spinning length was studied for four different polyesters. The experimental results are in accordance with non-isothermal and viscoelastic computations.     

Septorine and N-methoxy septorine,substituted pyrazines from the fungus Septoria nodorum berk

On the basis of ¹H nmr correlations with synthetic analogs, structures $\text{1}$ and $\text{2}$ are proposed for septorine and N-methoxy septorine, two p-hydroxybenzoyl 1-isobutyl substituted pyrazines obtained from the fungus $\text{Septoria nodorum}$ Berk, a parasite of wheat.     

Tracking elementary particles near their primary vertex: A combinatorial approach

Colliding beams experiments in High Energy Physics rely on solid state detectors to track the flight paths of charged elementary particles near their primary point of interaction. Reconstructing tracks in this region requires, per collision, a partitioning of up to 10³ highly correlated observations into an unknown number of tracks. We report on the successful implementation of a combinatorial track finding algorithm to solve this pattern recognition problem in the context of the ALEPH experiment at CERN. Central to the implementation is a 5-dimensional axial assignment model (AP5) encompassing noise and inefficiencies of the detector, whose weights of assignments are obtained by means of an extended Kalman filter. A preprocessing step, involving the clustering and geometric partitioning of the observations, ensures reasonable bounds on the size of the problems, which are solved using a branch & bound algorithm with LP relaxation. Convergence is reached within one second of CPU time on a RISC workstation in average.     

Mechanism of sulfur extrusion from thiirane

The thermal decomposition of thiirane $\text{1}$ to olefin $\text{2}$ is not a first order reaction, and is therefore not a simple chelotropic process.