Abstract: A coupling structure of a fuel assembly includes a screw coupling means to provide a coupling structure of a fuel assembly which prevents foreign matters from mixing in the fuel and in which no vertical play is generated at a fitting portion between a latch sleeve 10 and a lock key 20. The coupling structure of the fuel assembly includes: the latch sleeve 10 having a projecting portion 11 formed at an upper end portion thereof; an upper nozzle 30 having formed therein a latch sleeve installation hole 31 into which the upper end portion of the latch sleeve 10 is inserted; and the lock key 20 which is installed inside the latch sleeve installation hole 31, and which has an opening portion 21 formed on a bottom surface thereof, the opening portion 21 having a shape corresponding to the projecting portion 11. The screw coupling means screw couples the lock key 20 to the upper nozzle 30 with a male screw thread 23 formed on a side surface of the lock key 20.

Abstract: A cephem compound or pharmaceutically acceptable salt thereof represented by the formula I: wherein R1 and R2 may be the same or different and each represent hydrogen atom, nitro or cyano; R3 represents C1-C6 alkyl which may be substituted with carboxyl; R4 represents hydrogen atom or amino; X represents —S— or —SO—, there being no case where both of R1 and R2 are simultaneously hydrogen atom.

Abstract: A cephem compound or pharmaceutically acceptable salt thereof represented by the formula I: 1