High quality GaAs films with dislocation densities of 2–3×106 cm−2 on (100) Si substrates have been obtained by thermal cycle growth using the metalorganic chemical vapor deposition method. Significant reduction effects of dislocation density in the GaAs layers on Si have been analyzed by a simple model, in which annihilation and coalescence of dislocations are assumed to be caused by dislocation movement under thermal stress. Relaxation of thermal stress in the GaAs films on Si during thermal annealing has also been observed.

Three new flavonoid glycosides, together with 15 known flavonoids, have been isolated from the leaves of Eriobotrya japonica, and characterized as (2S)- and (2R)-naringenin 8-C-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosides, and cinchonain Id 7-O-beta-D-glucopyranoside, respectively, based on spectral analyses including two dimensional (2D) NMR techniques. Higher proanthocyanidin fraction in the water-soluble portion of the extract was characterized as a procyanidin oligomer mixture mainly composed of undecameric procyanidin. These polyphenols have also been assessed for cytotoxic activity against two human oral tumor (human squamous cell carcinoma and human salivary gland tumor) cell lines. Selective cytotoxicity of the procyanidin oligomer between tumor and normal gingival fibroblast cells, and its possible mechanism, were also described.

In the "Rhapsody" cultivar of the carnation, which bears white flowers variegated with red flecks and sectors, a transposable element, dTdic1, belonging to the Ac/Ds superfamily, was found within the dihydroflavonol 4-reductase (DFR) gene. The red flecks and sectors of "Rhapsody" may be attributable to a reversion to DFR activity after the excision of dTdic1. The yellow color of the carnation petals is attributed to the synthesis and accumulation of chalcone 2'-glucoside. In several of the carnation cultivars that bear yellow flowers variegated with white flecks and sectors, both the chalcone isomerase (CHI) and DFR genes are disrupted by dTdic1.

Anthocyanin is the principal pigment in flowers, conferring intense red-to-blue cyanic colours on petals and helping to attract pollinators. Its biosynthesis involves glycosylation steps that are important for the stability of the pigment and for its aqueous solubility in vacuoles. Here we describe anthocyanin biosynthesis in roses (Rosa hybrida), which is unlike the pathway used in other flowers in that it relies on a single enzyme to achieve glycosylation at two different positions on the precursor molecule. Phylogenetic analysis also indicates that this previously unknown glucosyltransferase enzyme may be unique to roses, with glycosylation having apparently evolved into a single stabilizing step in other plants.

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