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A high dose impurity doping process for 4H-SiC crystals has been developed using electron cyclotron resonance (ECR) sputtered carbon cap film and ECR plasma ashing. ECR-sputtered carbon films are newly found crystalline carbon films of which the hardness is comparable to that of diamonds. Since this carbon film showed such a high thermal tolerance that the hardness did not change after 1900oC annealing, this carbon cap film worked well for suppressing roughening during annealing for aluminum-ion implanted 4H-SiC. Cap carbon film can be removed successfully by using high density ECR plasma ashing.

We studied the effect of menatetrenone, a vitamin K2homolog, on bone resorption stimulated by interleukin‐1α (IL‐1α), prostaglandin E2(PGE2), parathyroid hormone (PTH), and 1,25‐dihydroxyvitamin D3[1,25‐(OH)2D3]. Bone‐resorbing activity was assessed by measurement of calcium and hydroxyproline in the media and calvariae. IL‐1α (0.1–100 U/ml), 1,25‐(OH)2D3(1010‐10−7M), PGE2(10−9‐10−6M), and PTH (3 × 10−8‐3 × 10−7M) dose dependently increased the levels of calcium and hydroxyproline in the medium. Indomethacin (10−6M) completely inhibited bone resorption induced by IL‐1α and partially inhibited bone resorption induced by 1,25‐(OH)2D3. However, indomethacin did not affect the action of PGE2or PTH. Menatetrenone (3 × 10−6‐3 × 10−5M) inhibited the bone resorption induced by IL‐1α (2 U/ml), PGE2(10−7M), PTH (3 × 10−7M), and 1,25‐(OH)2D3(3 × 10−10M) in a dose‐dependent manner. Menatetrenone also inhibited the PGE2production stimulated by IL‐1α. These results indicate that menatetrenone may inhibit bone resorption through at least two different mechanisms; one possibly is an inhibitory effect on prostaglandin production.