Described herein are methods of filling features with tungsten, and related systems and apparatus, involving inhibition of tungsten nucleation. The compounds of this invention possess both \u03b22 adrenergic receptor agonist and muscarinic receptor antagonist activity. The circuit comprises a H-bridge with matched power transistors, a sine generator for driving the H-bridge and a regulator for sensing the power applied to the antenna and controlling the current amplitude of the sine wave output by the sine generator. Some sensors can identify the type of agent and transmit the agent type. The inner decorative member is also provided with a weight-balancing member. More particularly, the present invention discloses the use of a power booster in conjunction with a radio-frequency linear power amplifier to reduce intermodulation distortion of an amplified signal.