Abstract: A control rod drive mechanism (CRD) capable of more securely preventing outflow of water when a scram piping is broken is provided. In a CRD, a ball check valve is provided in a flange provided in a lower end portion of an outer tube. The ball check valve includes a ball, a retainer, and a ball support mechanism, and the retainer has a valve flow channel. The ball support mechanism for supporting the ball is provided in a lower opening portion. A height of an upper end of the ball support mechanism is set so as not to bring the ball into contact with an upper corner portion of the lower opening portion.

Abstract: The present invention relates to novel pharmaceutical use of forskolin derivatives represented by the general formula: ##STR1## wherein R.sup.1, R.sup.2 and Ac are as defined later ##STR2## (wherein R.sup.3 and R.sup.4 are each hydrogen or lower alkyl group, or R.sup.3 and R.sup.4 may be combined to represent lower alkylene group which may have oxygen or nitrogen atom in the linking chain, and n is an integer of 1 to 5); R.sup.2 represents hydrocarbon group having 2 to 3 carbon atoms; and Ac represents acetyl group.The above-mentioned forskolin derivative or a physiologically acceptable salt thereof can be used as a platelet aggregation inhibiting or controlling agent, spasmolytic agent, therapeutic agent for skin ulcer, peripheral circulation improving agent for limbs and differentiation inducing and promoting agent.

Abstract: Novel .alpha.-methyl-.beta.-aminopropiophenone derivatives having bronchodilator activity represented by the following general formula: ##STR1## where R represents alkyl having 1-6 carbon atom benzyl or phenyl; R.sub.1 and R.sub.2 individually represent alkyl having 1-6 carbon atom or they form, joining to each other together with the adjacent nitrogen atom with or without intervening an atom other than carbon atom, a saturated heterocyclic ring which may be substituted with lower alkyl; n is an integer of 0, 1 or 2 on the proviso that R represents methyl or ethyl if n is 0, as well as their non-toxic salts are presented. Method of producing the new derivatives and the bronchodilatation method using them are disclosed as well.