关键词: fluctuation phenomena, interactions of biosystems with radiations

Abstract: Intracellular calcium ion concentration oscillation in a cell subjected to external noise and irradiated by an electromagnetic field is considered. The effects of the intensity $E_{0}$, the polar angle $\theta $ and  the frequency $\omega $ of the external electric field on steady-state probability distribution and the mean Ca$^{2 + }$ concentration, respectively, are investigated by a numerical calculation method. The results indicate  that (i) variation of $\omega $ cannot affect the intracellular calcium oscillation; (ii) the steady-state probability distribution presents a meaningful modification due to the variations of $E_{0} $ and $\theta $, while variation of $\theta $ does not affect the steady-state probability distribution under the condition of a small $E_0 $, and $E_0 $ cannot affect the steady-state probability distribution either when $\theta = \pi/2$; (iii) the  mean Ca$^{2 + }$ concentration increases as $E_0 $ increases when $\theta < \pi / 2$ and, as $\theta $ increases, it first increases and then decreases. However, it does not vary with $E_0 $ increasing when $\theta = \pi/2$,  but it increases with $\theta $ increasing when $E_0 $ is small.

Key words: fluctuation phenomena, interactions of biosystems with radiations