The effects of the Bi 3+ introduction and the oxygen release and storage abilities on selective oxidation of glycerol into dihydroxyacetone (DHA) were demonstrated using Pt/CeO 2-ZrO 2-Bi 2 O 3-SnO 2 /SBA-16 (SBA-16: Santa Barbara Amorphous No. 16) catalysts. By introducing Bi 3+ or Sn 4+/2+ ions into the CeO 2-ZrO 2 promoter, the oxygen release and storage abilities were enhanced, which led to increased glycerol conversion. The improvement in the DHA yield was affected by the introduction of Bi 3+ , which might accelerate selective oxidation of a secondary hydroxy group in glycerol caused by the geometric effect. The highest activity was obtained for Pt/Ce 0.64 Zr 0.16 Bi 0.15 Sn 0.05 O 2−δ /SBA-16, which showed high oxygen release and storage abilities and a high number of Bi 3+ ions, with the DHA yield increasing to 53% and high rates of glycerol conversion (74%) and DHA selectivity (72%) after reaction at a moderate temperature of 30°C for 4 h in atmospheric air.

Pt/La1−xBixOF/SBA-16 (SBA-16: Santa Barbara Amorphous No. 16) catalysts were prepared to produce dihydroxyacetone (DHA) from glycerol under moderate condition. By using 7 wt% Pt/16 wt% La0.95Bi0.05OF/SBA-16, the DHA yield reached...

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As based on the effectiveness of the caudal resection of the pancreas in alleviating the epileptic seizures, Tokuoka (1951) has suggested the close relationship of zinc to brain excitability.To verify this assumption the effect of zinc on brain excitability was studied.1. The brain excitability of the zinc deficient suckling mice (Nishimura), using the electroshock seizure threshold (EST) and maximal seizure duration (MES) techniques by Woodbury's apparatus, was slightly elevated in EST and significantly shortened in MES compared with the control mice.2. A marked lowering in EST with no significant change in MES was observed in the chronic zinc overdosed mice produced by the oral or subcutaneous administration of zinc chloride.3. Intracerebral injection of zinc, dissolved in 0.01 ml of Ringer's solution, by the method of Haley and Mc Cormick with our modification, produced certain generalized effects in the unanaestheitzed mice; i.e. a 2 r dose of zinc caused hyperexcitability, running and jumping of 3 to 5 min. duration. When the dose was increased to 3 r, the above response was followed by a typical tonic seizure after the latent time of 30 to 110 sec. No or different responses were observed after the injection of the same dose of other metals (Mn, Pb, Co, Ag, Cu, Fe).4. Brain carbonic anhydrase activity was lowered in the zinc deficient suckling mice, while the activity was not changed in the zinc overdosed mice. This finding accords with the view that brain carbonic anhydrase is concerned with MES. The mechanism of the lowering in EST is obscure.-261 -