Nanoscale devices for energy conversion require the transfer of electrons from one compartment to another. The enzyme complex I, which in vivo mediates electron transfer from NADH to ubiquinone, is an intriguing candidate for this role in nanodevices. However, complex I normally requires the presence of lipids to remain active, potentially limiting its application. Here we demonstrate for the first time that complex I can be actively reconstituted in the synthetic membrane of amphiphilic triblock copolymer vesicles. The functionality of the reconstituted protein was characterized by EPR and activity assays. Its activity is strongly influenced by the molar mass and the block length of the membrane‐forming polymers, and increases with increasing membrane thickness.magnified image

The self‐assembly of amphiphilic calix[4]arenes with either a carboxylic acid or a trimethyl ammonium head group and different alkyl chains in aqueous solution was investigated. The carboxylated calixarene forms vesicles in dilute solution and stable monolayers on water. In contrast, the ammonium head group provides high water solubility with no observed aggregation. At high concentrations, all calixarene amphiphiles form lyotropic liquid crystals.

Microstructure phenomena resulting from high-temperature oxidation of three nickel-base superalloys were studied by microstructure examinations. Disappearance, nature modification, volume fraction evolution or precipitation of carbides were observed in the alloys near the external surface, depending on the temperature and the chemical composition of the alloys. Thermodynamic calculations allowed to better know what happened to carbon and to quantify its new distribution. The alloys studied lost a more or less great part of their sub-surface carbon content at 1200 • C while carbon seemingly diffused deeper in the alloy at 1100 • C and 1000 • C. The latter part of carbon promoted the coarsening of the pre-existing carbides, some modifications of their natures or the precipitation of new carbides in the matrix, then the occurrence of a new-carbides zone.

Experiments and thermodynamic calculations were performed on three nickel-base alloys containing chromium, carbon and tantalum. Solidus and liquidus temperatures, natures and surface fractions of the carbides after an exposure for 100 hours at 1000°C, 1100°C and 1200°C, were determined for each alloy. These results are compared with calculated results, using a thermodynamic database. A good agreement was generally found for the solidus temperatures but less for the liquidus ones. For alloys containing chromium carbides alone, carbides fractions and matrix compositions correspond to calculation results. But the presence of tantalum carbides in the third alloy was not predicted by calculations.

For the first time, the covalent immobilization of oligonucleotides double helices onto surfaces prior to sequential denaturation and rehybridization is proven to lead to optimal hybridization efficiency. Two indirect methods were used for monitoring these reactions in situ: the quartz crystal microbalance with dissipation monitoring (QCM-D) and the wavelength interrogated optical sensor (WIOS, Bright Reader). Both techniques led to the result that with this immobilization approach one could reach nearly 100% hybridization efficiency. Moreover, applying the polymer theory to the adsorption of nucleotide sequences onto surfaces, we demonstrate, that for single stranded sequences the coil conformation prevails over the stretch one.