Evolution of spatiotemporal patterns during the electrodissolution of metals: Experiments and simulations

Spatiotemporal patterns including accelerating fronts, rotating waves, and homogeneous oscillations evolve during the electrodissolution of metals like cobalt and iron that exhibit passivity under potentiostatic control. The nature of the patterns is determined by long-range (nonlocal) coupling through the electric field which in turn is influenced by the geometry of the electrochemical cell, the applied potential, and the conductivity of the electrolyte. A two-variable model in a three-dimensional geometry is presented which is able to simulate the essential features of the experimental system.(c) 2002 American Institute of Physics.     

Labelling of [Leu5]-enkephalin with organometallic Mo complexes by solid-phase synthesis

The neuropeptide leucine-enkephalin ([Leu5]-enkephalin) has been covalently labelled with the two organometallic Mo carbonyl complexes Mo(R-His)(allyl)(CO)2 (His = N delta,N,O-L-histidinate) and Mo(R-bpa)(CO)3 (bpa = bis(2-picolyl)a-mine) on the resin as the last step of a solid-phase synthesis scheme and in solution.     

Synthesis of the first 1,2,3,4-azatriphospholene complex

Synthesis of the first 1,2,3,4-azatriphospholene complex was achieved by heating a solution of a P-phenyl-substituted 7-phosphanorbornadiene tungsten complex and triphenylphosphonio cyanomethylide, whereby CH-insertion products were formed in a competing reaction; these results also provide first evidence for the ability of electrophilic terminal phosphanediyl complexes to react at the ylide carbon atom and at the carbonitrile nitrogen atom of Wittig-ylides having a nitrile functional group; the structures of both complexes were established through X-ray single-crystal diffraction studies.     

Surface plasmon-coupled emission and Fabry-Perot resonance in the sample layer: A theoretical approach

A theoretical approach is used to investigate the coupling of surface plasmon-coupled emission to Fabry-Perot resonance in the sample layer. Quantities investigated are emission angles, polarization, power levels, and fluorescence lifetimes. The results are compared to experimental findings. For comparison a layered structure without surface plasmons, possessing only dielectric Fabry-Perot resonances, is explored. This structure seems to be amenable to s-polarization only but is in principle loss-less and has more degrees of freedom for design and optimization.     

Conjugation of a novel histidine derivative to biomolecules and labelling with [99mTc(OH2)3(CO)3]+

The new histidine derivative 3-[1-[3-(9H-fluoren-9-ylmethoxycarbonylamino)-propyl]-1H-imidazol-4-yl]-2-(3-trimethylsilanyl-ethylcarboxyamino)-propionic acid methyl ester (7) has been prepared via alkylation of the histidine urea derivative (7S)-5,6,7,8-tetrahydro-7-(methoxycarbonyl)-5-oxoimidazo-[1,5-c]-pyrimidine (2) with Fmoc-protected 3-iodopropyl-amine, followed by ring opening with 2-trimethylsilylethanol. After Fmoc cleavage by HNEt2, the histidine amine derivative was coupled to biotin, to the pentapeptide leucine-enkephalin and to Vitamin B12-b-acid by amide formation, employing TBTU as the coupling reagent. In order to make the histidine accessible for labelling, the teoc protecting group was removed by either NBu4F (for the biotin conjugate) or by TFA (for the enkephalin and B12 conjugates). Reaction of a 10(-4) M solution of the bioconjugates with [99mTc(H2O)3(CO)3]+ at 50 degrees C for 30 min led to the formation of one single new peak in the HPLC radiochromatogram in each case, confirming quantitative labelling of the respective biomolecules. To assess the nature of the labelled compounds, the rhenium analogues with Re(CO)3 were also synthesised and similar retention times confirmed the identity with the 99mTc labelled conjugates.     

The first oligopeptide derivative of 1'-aminoferrocene-1-carboxylic acid shows helical chirality with antiparallel strands

The unnatural organometallic amino acid 1'-aminoferrocene-1-carboxylic acid (Fca) induces a turn structure in a tetrapeptide with anti-parallel strands which is stabilized by two intra-molecular hydrogen bonds in the solid state and in solution.     

Real Paley-Wiener Theorems

The aim of this paper is to exhibit a real Paley–Wienerspace sitting inside the Schwartz space, and to give a quickand simple proof of a Paley–Wiener-type theorem. A simpleand elementary proof of a theorem postulated by H. H. Bang isalso given. 2000 Mathematics Subject Classification 42A38.