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The study and the investigation of structural and dynamical properties of complex systems have attracted considerable interest among scientists in general and physicists and biologists in particular. The present review paper represents a broad overview of the research performed over the nonlinear dynamics of DNA, devoted to some different aspects of DNA physics and including analytical, quantum and computational tools to understand nonlinear DNA physics. We review in detail the semi-discrete approximation within helicoidal Peyrard–Bishop model and show that localized modulated solitary waves, usually called breathers, can emerge and move along the DNA. Since living processes occur at submolecular level, we then discuss a quantum treatment to address the problem of how charge and energy are transported on DNA and how they may play an important role for the functioning of living cells. While this problem has attracted the attention of researchers for a long time, it is still poorly understood how charge and energy transport can occur at distances comparable to the size of macromolecules. Here, we review a theory based on the mechanism of ‘self-trapping’ of electrons due to their interaction with mechanical (thermal) oscillation of the DNA structure. We also describe recent computational models that have been developed to capture nonlinear mechanics of DNA in vitro and in vivo , possibly under topological constraints. Finally, we provide some conjectures on potential future directions for this field.

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Investigation of the influence of external fields on living systems is one of the most interesting and rapidly developing areas of modern biophysics. However, the mechanisms of such an impact are still not entirely clear. One approach to the study of this issue is associated with modeling the interaction of external fields with internal mobility of biological objects. In this paper, this approach is used to study the effect of external fields on the motion of local conformational distortions-kinks, in the DNA molecule. Realizing and taking into account that on the whole this task is closely connected with the problem of the mechanisms of regulation of vital processes of cells and cellular systems, we set the problem-to investigate the physical mechanisms regulating the motion of kinks and also to answer the question whether permanent and periodic fields can play the role of regulators of this movement. The paper considers the most general case, when constant and periodic fields are switching on and off asynchronously. Three variants of asynchronous switching on/off are studied in detail. In the first variant, the time intervals (or diapasons) of the actions of the constant and periodic fields do not overlap, in the second-overlap, and in the third-the intervals are putting in each other. The calculations were performed for the sequence of plasmid pTTQ18. The kink motion was modeled by the McLaughlin-Scott equation, and the coefficients of the equation were calculated in a quasi-homogeneous approximation. Numerical experiments showed that constant and periodic fields exert a significant influence on the character of the kink motion and regulate it. So the switching on of a constant field leads to a rapid increase of the kink velocity and to the establishment of a stationary velocity of motion, and the switching on of a periodic field leads to the steady oscillations of the kink with the frequency of the external periodic field. It is shown that the behavior of the kink depends on the mutual arrangement of the diapasons of the action of the external fields. As it turned out, events occurring in one of the two diapasons can affect the events in the other diapason, even when the diapasons are sufficiently far apart. It is shown that the overlapping of the diapasons of action of the constant and periodic fields leads to a significant increase in the path traversed by the kink to a complete stop. Maximal growth of the path is observed when one diapason is putting in each other. In conclusion, the question of how the obtained model results could be related to the most important task of biology-the problem of the mechanisms of regulation of the processes of vital activity of cells and cellular systems is discussed.