The relationships between the valence state of titanium in MgCI,-supported titanium catalysts and polymerization performances for ethylene and propylene were studied. When the titanium species of the supported titanium catalyst 1 was preliminarily reduced by treating it with AlEt3, the resulting catalyst system 2 had lost the activity for propylene polymerization completely. The catalyst activity for ethylene polymerization was found to be reduced to 20% of that of the original catalyst 1. In the AlEt3-pretreated catalyst 2 no Ti4+ is found and 80% of the total titanium is present as Ti2+. The catalyst system 2 plus AlEt3, however, does exhibit activity towards ethylene-propylene copolymerization, propylene insertion being possible if the end of the growing polymer chain is an ethylene unit. The titanium in the AlEt3-reduced catalyst 2 could be oxidized again by treatment with various agents. The oxidized catalysts 3, in conjunction with freshly added AIEt, as cocatalyst, are active for propylene polymerization and show increased activity for ethylene polymerization in relation to the extent of oxidation. 0025-116X/84/$03.00Polymerization of propylene: The same procedure was adopted. Ethylene-propylene copolymerization: The same procedure was adopted. The mole ratio of the ethylene/propylene feed was 9/1. Analysis of thepolymers:The stereoregularity (1.1.: Isotacticity index) of polypropylene was obtained from the weight percent of polymers insoluble in boiling heptane. This composition of the ethylene-propylene copolymers was obtained from the IR spectra of the film (deformation vibration of -CH3: 1380 cm-'). Results and discussion Reduction of the supported catalystThe valence state of titanium in the original MgC1,-supported titanium catalyst 1 was confirmed to be four by polarographic measurements. After AlEt,-treatment of the solid catalyst 1, all the Ti4+ was found to be reduced to Ti2+ or Ti3 + (it is known that the reduction of T i c 4 by AlEt, results in the formation of Ti2+ and Ti3+ as shown

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Seven hours after suicidal ingestion of about 21 g of boric acid, a 26-year-old female admitted to our hospital in a state of slightly impaired consciousness, with frequent vomiting, shivering, fever and skin flush. Immediately, gastric lavage, followed by administration of activated charcoal and laxative (MgSO4), was performed. In order to ensure her urination, fluid infusion therapy was conducted with the aid of diuretics (furosemide). Since the serum concentrations of boric acid was very high, hemodialysis was carried out twice during the first 39 h. She responded well to the above mentioned treatment and was discharged 12 d post-admission without any sequelae. The concentrations of boric acid in serum and urine were measured in appropriate intervals with our modified Miyamoto's method, and the pharmacokinetics of boric acid were analyzed. The concentration of boric acid in serum and urine at the beginning of treatment was 465 micrograms/ml and 3.40 mg/ml, respectively. The half-life of boric acid in serum was 13.46 h, whereas it was shortened to 3.76 h during hemodialysis. The total body clearance was 0.99 l/h, while it increased to 3.53 l/h by hemodialysis. The additional removal of boric acid by hemodialysis was estimated to be about 5 g. It was concluded that the hemodialysis was very useful in the treatment of boric acid poisoning, because it accelerated the elimination of boric acid about four times faster than with conventional treatment.

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