In an engine in which a lift amount of a valve can be changed continuously, an engine valve operating system including a valve lift-changing mechanism is capable of increasing and decreasing the lift amount of the valve without changing an opening angle for the valve and capable of decreasing a tappet clearance in accordance with a decrease in lift amount of the valve. The front substrate has multiple first and second common electrodes respectively connected to a first and a second contact pads. The force transferring portion is such as to distance the force receiving portion from the free surface so as to define between the force receiving portion and the free surface a region which can be filled at least in part with the cement material of the layer of cement material. Also, a current sense voltage provided by the current sense amplifier is sampled when the low-side transistor is on, and held when the low-side transistor is off. In the shaped element composite a first shaped element can overlap in sections up to three further shaped elements in a second planes thereof. The skin lightening is achieved using siRNA oligonucleotides which are able to achieve this using much lower concentration as compared to known chemical actives.