I. Introduction
Biological effects of intense pulsed electric fields (PEFs) have been reported over the past three decades. Neumann firstly reported in 1972 permeability changes induced by PEFs in membrane [1]. PEFs with a pulse length of longer than are generally used for electroporation because the cell membrane acts as a capacitor and has to be charged to a sufficient voltage to cause membrane defects [2]. Schoenbach et al have started using nanosecond pulsed electric fields (nsPEFs) and reported their effects on various kinds of mammalian cells over the past decade [3]. Application of nsPEFs to biological cells results in intracellular effects with the intense electric field inside the cell seemingly adding a new stress to the internal biological system which will potentially be used for biotechnology and medical treatment.