Dimensional stability of wood acetylated with acetic anhydride solution of glucose pentaacetate

Five wood species were acetylated with acetic anhydride (AA) solution of glucose pentaacetate (GPA) at 120°C for 8h, and the effect of GPA on the dimensional stability of the acetylated wood was investigated. Some GPA was introduced into the wood cell wall during acetylation. The GPA remaining in the cell lumen penetrated the cell wall effectively after heating to more than 140°C for 10min. The bulking effects of GPA resulted in a 10%–30% increase in the anti-swelling efficiency of the acetylated wood with 20% GPA/AA solution in place of AA. Hydrophobic GPA did not deliquesce under highly humid conditions and it remained in the cell wall after boiling in water.Part of this paper was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 1988     

Changes in nitrogen metabolism in rice seedlings infected with Piricularia oryzae cavara

Blast disease is one of the biggest diseases of rice plant in Japan. For example, in 1953, the total area of damage by blast disease was about 160 × 10⁴ hectare and the decreased yield of rice Was about 67.5 × 10⁴ ton in Japan. There have been many studies on blast disease for a long time. Tanaka and Katsuki (7)studied the relation between environmental conditions and blast disease. They always used adult healthy rice plants as plant materials and have not analysed the plants damaged by blast fungus directly. They suggested the presence of growth-promoting factors of blast funngus especially in susceptible rice varieties. Tamari and Kaji (5, 6) suggested that the blast fungus produced some effective toxic substances which might cause the disease. Suzuki, Doi and Toyoda (4) continued to study the mechanism of rice blast resistance and they have proposed 3 phases of resistance. They are (a) resistance and environtmental factors, (b) resistance and host camponents and (c) relation of host variety to fungus race.     

Fertility of bitches in which estrus was prevented with implantations of chlormadinone acetate for four years

The recurrence of estrus and fertility after removal of a subcutaneous chlormadinone acetate implant (CMA-I) administered to prevent estrus for 4 years, was investigated in 8 female dogs and the results compared with those for 4 untreated female dogs (control group). The sex hormones present during the estrous cycle were also investigated. There were no significant differences in the estrous cycle after removal of the implant between the CMA-I-treated group and the control group. However, although conception was achieved after mating and no uterine diseases developed in the control group, only 5 (4 dogs, 41.7%) of the 12 cases (6 dogs) in which mating took place at the second to fourth estrus after the removal of CMA-I resulted in pregnancy in the CMA-I-treated group. Furthermore, 6 (75.0%) of the 8 dogs in the CMA-I-treated group developed uterine diseases including pyometra or hydrometra. There were no significant differences in plasma progesterone, LH and prolactin levels between the non-pregnant and pregnant dogs in the CMA-I-treated group or control group. These results suggest that long-term implantation of CMA-I affects fertility after the implant is removed.