Background Cardiac implantable electric devices are commonly used to treat heart failure. Little is known about temporal and geographic variation in use of cardiac resynchronization therapy (CRT) devices in usual care settings.
A hammer drill, also known as a rotary hammer, roto-drill or hammering drill, (see also rotary drill) is a rotary drill with a hammering action. The hammering action provides a short, rapid hammer thrust to pulverize relatively brittle material and provide quicker drilling with less effort.
Crystal structure of rotaxane with a cyclobis(paraquat-p-phenylene) macrocycle. A rotaxane is a mechanically interlocked molecular architecture consisting of a dumbbell shaped molecule which is threaded through a macrocycle (see graphical representation). The name is derived from the Latin for wheel (rota) and axle (axis).