Barnes Frank S, Greenebaum Ben
Department of Electrical and Computer Engineering, University of Colorado, Boulder, Colorado.
Bioelectromagnetics. 2015 Jan;36(1):45-54. doi: 10.1002/bem.21883. Epub 2014 Nov 15.
It is proposed that radical concentrations can be modified by combinations of weak, steady and alternating magnetic fields that modify the population distribution of the nuclear and electronic spin state, the energy levels and the alignment of the magnetic moments of the components of the radical pairs. In low external magnetic fields, the electronic and nuclear angular momentum vectors are coupled by internal forces that outweigh the external fields' interactions and are characterized in the Hamiltonian by the total quantum number F. Radical pairs form with their unpaired electrons in singlet (S) or triplet (T) states with respect to each other. At frequencies corresponding to the energy separation between the various states in the external magnetic fields, transitions can occur that change the populations of both electron and nuclear states. In addition, the coupling between the nuclei, nuclei and electrons, and Zeeman shifts in the electron and nuclear energy levels can lead to transitions with resonances spanning frequencies from a few Hertz into the megahertz region. For nuclear energy levels with narrow absorption line widths, this can lead to amplitude and frequency windows. Changes in the pair recombination rates can change radical concentrations and modify biological processes. The overall conclusion is that the application of magnetic fields at frequencies ranging from a few Hertz to microwaves at the absorption frequencies observed in electron and nuclear resonance spectroscopy for radicals can lead to changes in free radical concentrations and have the potential to lead to biologically significant changes.
有人提出，通过弱、稳定和交变磁场的组合可以改变自由基浓度，这些磁场会改变核自旋态和电子自旋态的布居分布、能级以及自由基对各组分磁矩的排列。在低外部磁场中，电子和核角动量矢量通过内力耦合，这些内力超过外部场的相互作用，并且在哈密顿量中由总量子数F表征。自由基对以其未成对电子相对于彼此处于单重态（S）或三重态（T）的形式形成。在与外部磁场中各种状态之间的能量间隔相对应的频率下，会发生改变电子和核态布居的跃迁。此外，核之间、核与电子之间的耦合以及电子和核能级中的塞曼位移可导致跨越从几赫兹到兆赫兹区域频率的共振跃迁。对于具有窄吸收线宽的核能态，这可能导致幅度和频率窗口。对复合率的改变可以改变自由基浓度并改变生物过程。总体结论是，在电子和核共振光谱中观察到的自由基吸收频率范围内，从几赫兹到微波频率施加磁场可导致自由基浓度的变化，并有可能导致具有生物学意义的变化。
