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The flower-inducing and -inhibiting activities of phloem exudate (PE) prepared from cotyledons of Pharbitis seedlings were examined, using apex cultures in vitro from Pharbitis as a bioassay system. The PE was prepared from photoperiodically-induced cotyledons (SD-PE). The SD-PE was subjected to the following fractionations: When the SD-PE was extracted with CHCl3and then ethyl acetate, the inducing activity was located in the final aqueous fraction. The activity was localized in the diffusate when the aqueous fraction was dialyzed (molecular weight cut off was 10,000). The diffusate was fractionated by ion exchange chromatography, and flower-inducing activity was found in the fraction adsorbed onto anion exchange resin. When the fraction was applied to a Sep-Pak C18 cartridge, the activity eluted with 25% MeOH. As a result of the above fractionation, activity was increased about 30-fold. The nature of the flower-inhibiting activity of the PE taken from cotyledons exposed to continuous-light conditions was examined (CL-PE). The inhibiting activity was decreased as the cotyledons were exposed to longer dark periods; it appeared to be heat-stable. The CL-PE also inhibited flowering in Lemna. The CL-PE was subjected to the following fractionations: When the CL-PE was extracted with CHCl3and ethyl acetate, activity was located in the final aqueous fraction. Activity was localized in the diffusate when the aqueous fraction was dialyzed (molecular weight cut off was 10,000). When the diffusate was fractionated by ion exchange chromatography, the activity was found in the flow-through fraction. When the fraction was applied to a hydroxyapatite cartridge, the activity eluted with 25 mM sodium phosphate buffer. When the fraction was re-dialyzed (molecular weight cut off was 1,000), the diffusate contained the activity. As a result of the above fractionation, activity was increased about 10-fold.

Phloem exudate prepared from induced cotyledons of Pharbitis nil (SD-PE) showed flower-inducing activity, and the exudate from cotyledons of P. nil grown under continuous illumination (CL-PE) expressed flower-inhibiting activity in apex cultures of P. nil. Following fractionation by ion exchange chromatography, the flower-inducing activity of SD-PE was located in the fraction adsorbed on anion exchange resin (Dowex); the flow-through (FT) fraction from anion and/or cation exchange resins used to separate CL-PE inhibited flowering. The flower-inducing and -inhibiting activities of both fractions from SD-PE and CL-PE were examined in detail. The FT fraction of SD-PE inhibited, and the Dowex fraction of CL-PE induced flowering. The flower-inducing activity of Dowex fraction of SD-PE was about 100 times higher than the same fraction of CL-PE, and the inhibiting activity of FT fraction of CL-PE was about 10 times higher than the same fraction of SD-PE. Therefore, flowering in P. nil may be controlled by a quantitative balance between flower-inducing and -inhibiting substances.

A new cathode material for SOFCs was developed at the R&D Center of Noritake Co., Ltd. It contains La0.6Sr0.4TixFe1−xO3−δ(0 ≤ x≤ 0.4) (LSTF) and La0.6Sr0.4CoyFe1−yO3−δ(0 ≤ y≤ 1) (LSCF). Herein, we report the results of our performance evaluation of this cathode material. The optimum composition for the composite cathode material was determined to be LSCF 70 wt%–LSTF 30 wt%. Cathodes with this optimum composition exhibited neither fractures nor delamination from the electrolyte during thermal cycling. The developed cathode material also exhibited high power density and extremely high stability toward hydrogen and ammonia fuels.