Materials Literature
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New π-conjugated polymers are described, which entirely consist of aryl−aryl-coupled 1,4-diketo-2,5-dialkyl-3,6-diphenylpyrrolo[3,4- c ]pyrrole (DPP) units. The alkyl groups are n -hexyl ( 4a ) or 2-ethylhexyl ( 4b ) groups. The polymers are synthesized using nickel-promoted and palladium-catalyzed one-pot coupling re…
BACKGROUND: Metamorphosis is a complex, highly conserved and strictly regulated development process that involves the programmed cell death of obsolete larval organs. Here we show a novel functional role for the aspartic proteinase cathepsin D during insect metamorphosis. RESULTS: Cathepsin D of the silkworm Bombyx mo…
Highly stable hybrid unimolecular micelles with thermosensitive poly( N -isopropylacrylamide) (PNIPAM) shells incorporated with Ag nanoparticles were prepared in situ via a facile approach. Heating the hybrid unimolecular micellar solutions leads to the shrinkage of the PNIPAM shell and allows for tuning the relative…
The electronic transport properties of ultrananocrystalline diamond thin films grown from an argon-rich $\mathrm{Ar}∕\mathrm{C}{\mathrm{H}}_{4}$ microwave plasma have been investigated in the temperature range from 300 up to $700\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and as a function of nitrogen added to the gas phas…
Here we characterize a highly efficient approach for protein confinement and enzyme immobilization in NH(2)- or HOOC- functionalized mesoporous silica (FMS) with pore sizes as large as tens of nanometres. We observed a dramatic increase of enzyme loading in both enzyme activity and protein amount when using appropriat…
We demonstrate that niobium oxide exchanges oxygen with the atmosphere when illuminated by simulated sunlight. The oxygen exchange was found to take place for pristine niobium oxide films when illuminated in an oxygen atmosphere and when illuminated in an operational hybrid solar cell. The oxygen exchange was demonstr…
Infrared (IR) spectra were measured for cellulose Ibeta prepared from the mantle of Halocynthia roretzi over a temperature range of 30-260 degrees C to explore the temperature-dependent changes in hydrogen bonds (H-bonds) in the crystal. Structural changes at the phase transition temperature of 220 degrees C are eluci…
In this work we investigated the correlations between global gene expression patterns and environmental parameters in natural ecosystems. We studied the preferential gene expression of the iron oxidizer bacterium Leptospirillum ferrooxidans to adapt its physiology to changes in the physicochemical parameters in its na…
Die Cozusammenlagerung kurzer molekularer Drähte OPE1 mit chiralen Analoga OPE2, die beide CD-inaktiv sind, zeigt einen „Feldwebel-und-Soldaten“-Effekt, der zu einer Umwandlung vesikulärer Aggregate von OPE1 in CD-aktive helicale Nanoröhren führt (siehe Schema). Dies wird durch Circulardichroismus (CD), dynamische Lic…
This contribution aims at reviewing how reactive extrusion (REx) technique can participate in the design and development of biodegradable polymeric materials more particularly based on aliphatic polyesters issued from both renewable (agrochemical) and fossil (petrochemical) resources. On one side, REx will be approach…
Numerous regenerating tissues respond favorably to electrical stimulation, creating a need for a bioactive conducting platform for tissue engineering applications. The drive for biosensors and electrode coatings further requires control of the surface properties of promising conductive materials such as polypyrrole. H…
We have measured the Anisotropic Magnetoresistance (AMR) of ultra thin (5nm) Ga(0.95)Mn(0.05)As films. We find that the sign of the AMR can be positive or negative, which may depend on the direction of the current with respect to the crystal. At low temperatures, transport measurements and SQUID magnetometry suggest t…
Negative differential resistance (NDR) is tuned at junctions of electronically different dimer and trimer of Rose Bengal on an atomic flat gold (111) surface. Isolated molecule did not show any NDR. But it was induced to show double NDR with large peak to valley ratio (1.8~3.1) in room temperature via charging its nei…
The well known break-down of the Hall–Petch effect of the rise of the plastic resistance with decreasing grain size in polycrystalline metals, when the grain size drops into the nanometre range resulting in a peak plastic resistance at a grain size of about 12–15 nm, is explained by considering two alternative and com…
Direct partial oxidation of methane to synthesis gas on AFeO(3) (A = La, Nd, Eu) oxides by a novel sequential redox cyclic reaction in the absence of gaseous oxygen was investigated over a fixed-bed reactor. These oxides were prepared by the sol-gel method and characterized by X-ray diffraction (XRD) and X-ray photoel…
Ion complexation within cylinder-forming block copolymer thin films was found to affect the ordering process of the copolymer films during solvent annealing, significantly enhancing the long-range positional order. Small amounts of alkali halide or metal salts were added to PS- b -PEO, on the order of a few ions per c…
The properties of Mo_6S_3I_6 nanowires were investigated with ab initio calculations based on the density-functional theory. The molecules build weakly coupled one-dimensional chains with three sulfur atoms in the bridging planes between the Mo octahedra, each dressed with six iodines. Upon uniaxial strain along the w…
We study the effects of pressure on the electron-phonon interaction in MgB_2 using density-functional-based methods. Our results show that the superconductivity in MgB_2 vanishes by 100 GPa, and then reappears at higher pressures. In particular, we find a superconducting transition temperature T_c \~ 2 K for mu*=0.1 a…
In spite of several papers, the origin of visible luminescence from germanium nanocrystals in a SiO 2 matrix is controversial even today. Some authors attribute the luminescence to quantum confinement of charge carriers in these nanocrystals. On the other hand, surface or defect states formed during the growth process…
Infections caused by antibiotic-resistant luminescent Vibrios can cause dramatic losses in aquaculture. In this study, the short-chain fatty acid beta-hydroxybutyrate and its polymer poly-beta-hydroxybutyrate were investigated as possible new biocontrol agents. beta-Hydroxybutyrate was shown to completely inhibit the…