Abstract: The invention provides (i) a process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400.degree. C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2/1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al.sub.2 O.sub.

Abstract: The invention provides (i) a process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400.degree. C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2/1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al.sub.2 O.sub.

Abstract: The invention provides (i) a process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400.degree. C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2/1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al.sub.2 O.sub.

Abstract: Tetracalcium phosphate particles are prepared by sintering or fusing at a temperature of at least 1,400.degree. C. a mixture of a powder of calcium source and a powder of phosphorous source in a Ca/P molar ratio of 2:1 and about 0.05 to about 5 parts of aluminum compound per 1 parts of tetracalcium phosphate to be produced in terms of the theoretical amount and finely-dividing the product obtained.

Abstract: This invention provides a process for producing bicyclo[3.3.0]octanes expressed by the following formula [II] ##STR1## wherein R.sub.11 represents H, a one-equivalent cation or R.sub.1, R.sub..omega.' , represents R.sub..omega.' , and R.sub.21 represents H or R.sub.2,from a thiol compound expressed by the following formula [I], ##STR2## wherein R.sub.1 represents a C.sub.1-10 alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alicyclic group, a substituted or unsubstituted phenyl (C.sub.1-2)alkyl group or a tri(C.sub.1-7 hydrocarbyl)silyl group, Ar represents a substituted or unsubstituted aryl group, R.sub..omega. represents a substituted or unsubstituted C.sub.1-13 alkyl group or a substituted or unsubstituted C.sub.2-13 alkenyl group, and R.sub.2 represents a hydroxyl-protecting group.This process enables to obtain isocarbacyclines or synthetic intermediates therefor with industrial advantages.

Abstract: A novel prostacyclins expressed by the following formula (1) ##STR1## wherein a symbol between the 2-position and 3-position indicates single bond or double bond; G indicates --CO.sub.2 R.sup.5 or --CONR.sup.6 R.sup.7 in which R.sup.5 is a hydrogen atom, C.sub.1 -C.sub.10 alkyl group, substituted or unsubstituted alicyclic group, substituted or unsubstituted phenyl (C.sub.1 -C.sub.2) alkyl group, tri (C.sub.1 -C.sub.7) hydrocarbon-silyl group, or one equivalent cation, R.sup.6 and R.sup.7 are identical or different and each representing a hydrogen atom, or C.sub.1 -C.sub.10 alkyl group, or R.sup.6 and R.sup.7 are substituted or unsubstituted five to six-membered ring which may join together with a nitrogen atom to which they are linked and further contain a hetero atom; R.sup.1 indicates a hydrogen atom, or methyl group; R.sup.2 indicates an unsubstituted C.sub.3 -C.sub.8 alkyl group substituted or unsubstituted alicyclic group, or substituted C.sub.1 -C.sub.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating allergenicities.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating pulmonary fibrosis.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating liver disorders.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating opthalmological disorders.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating psychoneurological disorders.

Abstract: Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in mental diseases, disturbances in heart and vascular systems and are also effective against various cancers.

Abstract: Novel pharmacologically important organic germanium compounds (3-hydroxygermyl propionic acid salts) represented by the formula ##STR1## WHEREIN Met is a monovalent cation selected from the group consisting of Na, K, NH.sub.4, and NH.sub.2 (CH.sub.3).sub.2, or divalent cation selected from the group consisting of Ca and Mg, and wherein x is 1 when Met is a monovalent cation and x is 2 when Met is a divalent cation.These compounds possess valuable therapeutic properties for treating such physiological abnormalities as psychiatric and neurological disorders, metabolic disorder, cardivascular disorder, disorder of digestive organs, skin disease, allergic disease, Kidney dysfunction, hepatic dysfunction, obstetric and pediatric diseases, etc., and the process for preparing thereof.