チタン鋳造における鋳型温度の影響

The purpose of this study was to evaluate the titanium castability with a vacuum pressured type casting machine. We tested ethyl-silicate bonded investment "TITAVESTPS" of metal frame work. Four different mold temperatures (room temperature, 300℃, 600℃, and 900℃) were prepared for the present study, and casting was done in five times in each condition. When the mold temperature increased, high percentage of castability was gained. Mold temperature showed a highly significant (p<0.001) correlation on the castability. These results indicate that high performance of castability on the titanium was achieved when the mold temperature increased by using vacuum pressured type casting machine

DNA polymerases ν and θ are required for efficient immunoglobulin V gene diversification in chicken

Polν and Polθ have specialized functions in immunoglobulin gene rearrangements and only contribute to DNA repair when other homologous recombination–related DNA polymerases are absent

Electron microscopic study of the parathyroid gland of the calcium-treated hamster subjected to hypergravity environment

The ultrastructure of the parathyroid glands of calcium-treated golden hamsters subjected to 5 gravity environment was studied. In the calcium-treated animals exposed to hypergravity environment, the Golgi complexes and cisternae of the granular endoplasmic reticulum were significantly decreased compared with those of the animals exposed to hypergravity environment only and appeared to increase compared with those of the calcium-treated animals, but were almost similar to those of the control animals. In addition, many chief cells contained some prosecretory granules in the Golgi areas, some secretory granules situated close to the plasma membrane and many lysosomes. The morphology of the parathyroid glands in the calcium-treated animals exposed to hypergravity environment resembled that of the control animals. These results suggest that the parathyroid glands suppressed by treatment of calcium and stimulated in response to hypergravity environment may indicate the secretory activity of the parathyroid glands of the control animals

Electron microscopic pathological patterns of alveolar septum in acute dextran-induced and alloxan-induced pulmonary edema in dogs

We studied the incidence of electron microscopic pathological patterns of the alveolar septum observed 30 min after induction of pulrnonary edema by dextran-70 infusion (6 dogs, dextran group) and by alloxan injection (6 dogs, alloxan group). For comparable amounts of extravascular lung water in both dextran and alloxan groups, which were twice as much as control group (6 dogs), we characterized the pathological changes. The incidence of the electron microscopic pathological patterns that appeared in dextran group compared with that in control group was significantly high in terms of the widening of the interstitial space. dispersion and disarray of collagen fibrils, and erythrocytes in the interstitial space. The incidence in alloxan group compared with that in control group was significantly high in terms of the swelling of epithelial cells and endothelial cells as well as the widening of the interstitial space, and dispersion and disarray of collagen fibrils. We conclude that dextran causes interstitial changes exclusively and alloxan causes cellular changes primarily coupled with secondary interstitial changes in acute pulmonary edema