Abstract: Disclosed is a material for use in ophthalmologic organ replacement, which is transparent, has controllable physical properties, and can have physical properties suitable for use as an ophthalmic tissue when the hardness of a gel produced from the material or the fluidability of a sol produced from the material at a specific temperature or lower is varied. Specifically disclosed is an ophthalmologic composition capable of forming a gel, which comprises a polyethylene glycol that is represented by formula 1 and has one end modified with a long-chain alkyl group, a polyethylene glycol that is represented by formula 2 and has both ends modified with a long-chain alkyl group, and a solvent. R1—(CH2CH2O-)n1-R2 ??(Formula 1) [In formula 1, R1 represents an alkyl group having 1 to 4 carbon atoms; R2 represents an alkyl group having 16 to 22 carbon atoms; and n1 represents the average number of moles of added oxyethylene groups and falls within the range from 45 to 450.

Abstract: Multiple-phase transition copolymers are formed which can selectively bind and release a chemical, or which can selectively catalyze a specific chemical reaction.

Abstract: An interpenetrating gel and a method of forming an interpenetrating gel which undergoes a significantly large volume change in response to a physical or chemical stimululs is disclosed.

Abstract: An interpenetrating gel and a method of forming an interpenetrating gel which undergoes a significantly large volume change in response to a physical or chemical stimululs is disclosed.

Abstract: A process for producing crosslinked polymer particles which comprises a first step of polymerizing a polymerizable monomer containing from 0.1 to 2.0% by weight, based on the entire polymerizable monomer, of a crosslinkable monomer in a medium in which the polymerizable monomer is soluble but the resulting polymer is insoluble, to obtain crosslinked polymer particles having a particle size of from 0.8 to 10 .mu.m, and a second step of letting the crosslinked polymer particles absorb from 1 to 50 times by weight of a polymerizable monomer containing from 2 to 100% by weight, based on the entire polymerizable monomer, of a crosslinkable monomer in an aqueous medium, followed by polymerization to obtain crosslinked polymer particles having a particle size of from 1 to 30 .mu.m and a crosslinking degree of from 1.0 to 98%.

Abstract: A process for producing crosslinked polymer particles which comprises a first step of polymerizing a polymerizable monomer containing from 0.1 to 2.0% by weight, based on the entire polymerizable monomer, of a crosslinkable monomer in a medium in which the polymerizable monomer is soluble but the resulting polymer is insoluble, to obtain crosslinked polymer particles having a particle size of from 0.8 to 10 .mu.m, and a second step of letting the crosslinked polymer particles absorb from 1 to 50 times by weight of a polymerizable monomer containing from 2 to 100% by weight, based on the entire polymerizable monomer, of a crosslinkable monomer in an aqueous medium, followed by polymerization to obtain crosslinked polymer particles having a particle size of from 1 to 30 .mu.m and a crosslinking degree of from 1.

Abstract: A separation medium useful as an adsorbent of liquid chromatography for optical resolution of racemic mixtures is disclosed, which comprises a reversed phase support coated with an optically active amino acid derivative represented by formula (I): ##STR1## wherein R.sub.1 represents a straight or branched alkyl group having from 1 to 3 carbon atoms; and R.sub.2 and R.sub.3 each represents a straight or branched alkyl group having from 4 to 12 carbon atoms which may contain an aromatic group or an unsaturated alkyl group.The separation medium is applicable to optical resolution of a wide range of DL-amino acids and exhibits excellent durability.