Abstract: Provision of a porous ceramic material which rapidly induces bone tissue formation and has practical strength. A porous ceramic material 11 having substantially unidirectionally oriented pores 12, a porosity of 40-90%, and an average open area of one pore of 0.05×10?3-50×10?3 mm2 both in a first sectional surface perpendicular to the pore 12 orientation direction and a second sectional surface parallel to the first sectional surface and 5 mm distant from the first sectional surface in the pore 12 orientation direction. Using the material 11, when a cylindrical test piece (diameter 3 mm×height 5 mm, the pore 12 array direction as a height direction) made of the material is dipped in polyethylene glycol up to 1 mm from one end thereof, polyethylene glycol permeates through the whole test piece preferably within 30 seconds.

Abstract: An adsorbent for radioelement-containing waste composed of the following spherical layered double hydroxide (A) or spherical metal hydroxide (B) is provided. (A) is a nonstoichiometric compound represented by general formula (a) or (b): [M2+1-xM3+x(OH)2]x+[An?x/n·mH2O]x? . . . (a), [Al2Li(OH)6]x+[An?x/n·mH2O]x? . . . (b) wherein 0.1?x?0.4, 0<m, n represents a natural number of 1 to 4, M2+ represents at least one divalent metal, M3+ represents at least one trivalent metal, and An? represents at least one n-valent ion-exchangeable anion, and (B) is a spherical metal hydroxide containing a metal selected from the group consisting of the metal atoms belonging to Group II, Group IV, Group V, Group VI, Group XI, Group XII, and Group XIII of the periodic table, and the group consisting of Mn, Fe, Co, Ni, Pb, and Bi.

Abstract: An adsorbent for radioelement-containing waste includes spherical layered double hydroxide (A) or spherical metal hydroxide (B). (A) is a nonstoichiometric compound represented by general formula (a) or (b): [M2+1-xM3+x(OH)2]x+[An?x/n.mH2O]x???(a), [Al2Li(OH)6]x+[An?x/n.mH2O]x???(b) where 0.1?x?0.4, 0<m. The n represents a natural number of 1 to 4, M2+ represents at least one divalent metal, M3+ represents at least one trivalent metal, and An? represents at least one n-valent ion-exchangeable anion. (B) contains a metal selected from the group of Group II, Group IV, Group V, Group VI, Group XI, Group XII, and Group XIII of the periodic table, and the group of Mn, Fe, Co, Ni, Pb, and Bi. This adsorbent efficiently adsorbs and collects volatile iodine, a radioactive anion in wastewater, etc. providing a crack-resistant solidified article after a solidification treatment, and effectively confines the radioelement-containing waste with long-term stability.

Abstract: An adsorbent for radioelement-containing waste composed of the following spherical layered double hydroxide (A) or spherical metal hydroxide (B) is provided. (A) is a nonstoichiometric compound represented by general formula (a) or (b): [M2+1-xM3+x(OH)2]x+[An?x/n.mH2O]x? . . . (a), [Al2Li(OH)6]x+[An?x/n.mH2O]x? . . . (b) wherein 0.1?x?0.4, 0<m, n represents a natural number of 1 to 4, M2+ represents at least one divalent metal, M3+ represents at least one trivalent metal, and An? represents at least one n-valent ion-exchangeable anion, and (B) is a spherical metal hydroxide containing a metal selected from the group consisting of the metal atoms belonging to Group II, Group IV, Group V, Group VI, Group XI, Group XII, and Group XIII of the periodic table, and the group consisting of Mn, Fe, Co, Ni, Pb, and Bi.

Abstract: Provision of a porous ceramic material which rapidly induces bone tissue formation and has practical strength. A porous ceramic material 11 having substantially unidirectionally oriented pores 12, a porosity of 40-90%, and an average open area of one pore of 0.05×10?3-50×10?3 mm2 both in a first sectional surface perpendicular to the pore 12 orientation direction and a second sectional surface parallel to the first sectional surface and 5 mm distant from the first sectional surface in the pore 12 Orientation direction. Using the material 11, when a cylindrical test piece (diameter 3 mm×height 5 mm, the pore 12 array direction as a height direction) made of the material is dipped in polyethylene glycol up to 1 mm from one end thereof, polyethylene glycol permeates through the whole test piece preferably within 30 seconds.

Abstract: A calcium phosphate porous sintered body which comprises spherical pores communicating with one another substantially throughout the body with a porosity of 55% or more and 90% or less, and has an average diameter of the inter-pore communicating parts of 50 &mgr;m or more, a pore diameter of 150 &mgr;m or more, and a three-point bending strength of 5 MPa or more, and a method for producing the same.

Abstract: The present invention provides an absorbable barrier membrane for guided tissue regeneration which is useful for regeneration of animal tissues, including those of humans, the absorbable barrier membrane being superior in heat stability, processability, reproducibility, storage stability, bioabsorbablity, and tissue regeneration effects, and further provides a method for regeneration, using the absorbable barrier membrane, of a mandible, periodontal tissue, or defective tubulous bone, and particularly a defective tubulous bone which possesses a segmental bone defect in which both ends of the bone are in separate segments. The above objects are attained by an absorbable barrier membrane for use in guided tissue generation, comprising a lactic copolyester in which a polymerization catalyst is deactivated, as an essential component.