Hormone receptors.

Hormone receptors are proteins located on the cell membrane or in the cell cytoplasm. Their function is to recognize and bind the respective hormone; the biological action of the hormone originates from the hormone-receptor complex. Specific receptors have been found for all known hormones. Monitoring the equilibration between hormone, receptor, and hormone-receptor complex (“determination of receptor binding”) permits quantitative determinations of hormones, allows the characterization of endocrinal disturbances, and contributes to the elucidation of structure-affinity relationships.     

Strikte Konvergenz in Banachräumen

Ohne Zusammenfassung     

Pictorial representation of three-dimensional electron distributions through a perspective view of contour diagrams in a set of parallel planes

A method of graphically exhibiting detailed information about a three-dimensional electron distribution function f(x,y,z) is described. Contour lines f = constant are drawn on a set of equidistant parallel planes that intersect the distribution, and a perspective view of all contours on all planes is displayed. Representative examples are given.     

Synthesis and characterization of anti-[2.2](1,6)azulenophane

Two synthetic pathways affording $\text{anti}$-[2.2](1,6)azulenophane via fluoride induced 1,8 elimination from trimethylsilyl-tetraalkylammonium salts are described. Spectral data are reported that allow the structural assignment for the title compound.     

The Chemistry of Stable Carbenes. Part 2. Benzoin-type condensations of formaldehyde catalyzed by stable carbenes

Stable carbenes derived from thiazole, 1H-imidazole, and 4H-1,2,4-triazole are efficient catalysts for benzointype condensations of formaldehyde. Catalysts derived from N-substituted thiazolium salts trimerize formaldehyde to dihydroxyacetone ( II ). Catalysts based on 1,4-disubstituted 4H-1,2,4-triazol-1-ium salts give glycolaldehyde ( I ) as the main product and no II , whereas N,N′-disubstituted 1H-imidazol-3-ium salts yield mixtures of both products. The isolation of several intermediates in the catalytic cycle provide a better insight into the reaction mechanism.     

Opening of a 1,3-dioxolane by nucleophilic attack at a ketal methylene

A novel type of opening of an ethylene ketal has been observed in the reaction of 1 with alane RA1Me₂. The reaction is explained in terms of a nucleophilic attack on the ketal methylene synchronous with participation by one of the ketal oxygens in the opening of the epoxide function located across the 7-membered ring of 1.