A bicycle wheel securing structure includes a bicycle fork, an adapter and a holding member. The optical structure can include a first surface having an array of one or more sites, each site containing an assay, and a second surface configured such that the second surface is disposed within the laser resonating cavity forming a portion of the laser resonating cavity. The first gate controller includes a first gate transformer, and a leakage inductance of the first gate transformer forms a resonant circuit with an input capacitance of the first power transistor. The wire loop pawl is preferably a rod of elastically deformable material, bent to form an open loop and bent-over ends about which the pawl pivots with respect to the body of the safety hook when the latch is deformed and forced away from a distal end of the hook opening end of the safety hook. The first and the second ports can be combined to receive the electrical plug for high-speed signal transmission.