Abstract: The present invention provides a medicament for preventing and/or treating cognitive impairment, in particular Alzheimer's dementia, comprising 2-methyl-2-[(4-{(1E)-3-[2-(4-methylbenzoyl)-1H-pyrrol-1-yl]prop-1-en-1-yl}benzyl)oxy]propionic acid or a pharmaceutically acceptable salt or solvate thereof.

Abstract: A rust preventive composition which is obtained by blending at least one base oil selected from the group consisting of a hydrocarbon solvent, a mineral oil and a synthetic oil with, as essential components,(A) an organophosphoric ester calcium salt represented by the following general formula (1) in an amount of 0.1 to 5.0% by mass based on the total mass of the composition ##STR1## wherein R.sup.1 and R.sup.2 are each an alkyl group having 6 to 18 carbon atoms; and a and b are each an integer of 1 to 6,(B) water in an amount of 0.1 to 3.0 parts by weight based on 1 part by weight of the component (A), and(C) a rust inhibitor in an amount of 2.0 to 30% by mass based on the total mass of the composition.