A method for treating a microbial infection in a mammal, such as a human, comprising treating the mammal with a therapeutically effective amount of a polymer comprising an amino group or an ammonium group attached to the polymer backbone via an aliphatic spacer group. Here, the hermetic compressor is so constructed as to maintain a constant supply of the lubricating oil to the compressing mechanism by way of controlling operation in a manner to keep a surface level of the lubricating oil stable based on a detected result of the oil surface detector. A reference level setting portion 8 holds the level of the state monitoring signal at which an optimum recording state is obtained and outputs a reference level signal. The shape of the activation area is generally triangular with opposing side edges extending from an apex and the parent object being curved inwardly towards one another to also minimize trapping. Patterns are designed on corners of a region surrounded by electrodes arranged on the interposer in four directions.