The Soluble NAD+-Reducing [NiFe]-Hydrogenase from Ralstonia eutropha H16 Consists of Six Subunits and Can Be Specifically Activated by NADPH

A portable telephone assembly comprising first and second portions is disclosed. The first portion comprises a primary power source, is independently operable as a portable telephone and is arranged to be detachably connectable to the second portion. The second portion is arranged to be removably attachable to a user and comprises an auxiliary power source operable to supplement the primary power source when the first and second portions are connected.