A device made up of a textile tubular sheath, which can be implanted in the human body, suitable for containing a filling material and the ends of which are suitable for covering the ends of two portions of a single resected rib. The direct conversion receiver contains a low noise amplifier for amplifying a received RF signal and for outputting the amplified RF signal to a current switching down-conversion mixer. There is also provided a catalyst suitable for the vapor phase production of alkylene oxide from olefins and oxygen comprising an alumina-based carrier having a sodium solubilization rate no greater than 5 ppmw5 minutes; and catalytically reactive silver deposited on said carrier.