Cifra M
Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Czech Republic.
Biosystems. 2012 Sep;109(3):356-66. doi: 10.1016/j.biosystems.2012.06.003. Epub 2012 Jun 28.
Eigenmodes of the spherical and ellipsoidal dielectric electromagnetic resonator have been analysed. The sizes and shape of the resonators have been chosen to represent the shape of the interphase and dividing animal cell. Electromagnetic modes that have shape exactly suitable for positioning of the sufficiently large organelles in cell (centrosome, nucleus) have been identified. We analysed direction and magnitude of dielectrophoretic force exerted on large organelles by electric field of the modes. We found that the TM(1m1) mode in spherical resonator acts by centripetal force which drags the large organelles which have higher permittivity than the cytosol to the center of the cell. TM-kind of mode in the ellipsoidal resonator acts by force on large polarizable organelles in a direction that corresponds to the movement of the centrosomes (also nucleus) observed during the cell division, i.e. to the foci of the ellipsoidal cell. Minimal required force (10(-16) N), gradient of squared electric field and corresponding energy (10(-16) J) of the mode have been calculated to have biological significance within the periods on the order of time required for cell division. Minimal required energy of the mode, in order to have biological significance, can be lower in the case of resonance of organelle with the field of the cellular resonator mode. In case of sufficient energy in the biologically relevant mode, electromagnetic field of the mode will act as a positioning or steering mechanism for centrosome and nucleus in the cell, thus contribute to the spatial and dynamical self-organization in biological systems.
对球形和椭球形介质电磁谐振器的本征模进行了分析。选择谐振器的尺寸和形状以代表相间和正在分裂的动物细胞的形状。已识别出形状完全适合在细胞中定位足够大的细胞器(中心体、细胞核)的电磁模式。我们分析了这些模式的电场对大细胞器施加的介电泳力的方向和大小。我们发现球形谐振器中的TM(1m1)模式通过向心力起作用,该向心力将比细胞质具有更高介电常数的大细胞器拖向细胞中心。椭球形谐振器中的TM类模式对大的可极化细胞器施加力,其方向与细胞分裂期间观察到的中心体(也是细胞核)的移动方向相对应,即朝着椭球形细胞的焦点方向。已计算出该模式的最小所需力(10^(-16) N)、电场平方梯度和相应能量(10^(-16) J),以便在细胞分裂所需时间量级的周期内具有生物学意义。为了具有生物学意义,该模式的最小所需能量在细胞器与细胞谐振器模式的场发生共振的情况下可能会更低。在生物学相关模式中具有足够能量的情况下,该模式的电磁场将充当细胞中中心体和细胞核的定位或引导机制,从而有助于生物系统中的空间和动态自组织。