论文标题
在拥挤的环境中，半灵性聚合物的构象和横向波动的普遍性
Universality in conformations and transverse fluctuations of a semi-flexible polymer in a crowded environment
论文作者
论文摘要
我们研究了一个单一肿胀链的聚合物构象和横向波动的通用方面，其特征是轮廓长度$ l $和持续的长度$ \ ell_p $在二维（2D）中以及散装中的三个维度（3D），以及在不同的体积（ev）不同的体积（ev）不同的体积的不同量的不同体积的情况下。在没有EV颗粒的情况下，我们将先前确定的普遍尺度关系扩展在2D中（A. Huang，A。Bhattacharya和K. Binder，J。Chem。140，214902（2014））包括3D，并证明端到端到端到端距离$ \ langle $ \ langle r_n^2 \ rangle/（2 langle/fluct） $ \ sqrt {\ langle {l _ {\ perp}^2} \ rangle}/{l} $作为$ l/\ ell_p $的函数，在同一条主曲线上，其中$ \ langle r_n^2 \ rangle^2 \ rangle $和$ \ langle $ and $ \ langle $} $ ____ \ e}均方根端到端距离和横向波动。但是，与2D不同的是，由于EV相互作用的极端优势，高斯政权不存在，我们发现存在高斯政权，尽管在3D中非常狭窄。限制$ l/\ ell_p \ ll 1 $的缩放横向波动独立于物理维度，并将比例缩放为$ \ sqrt {\ langle {l _ {\ perp}^2}^2}^2} \ rangle} \ rangle}/{l}/{l} \ sim（l/\ ell_p）对于$ l/\ ell_p \ gg 1 $，缩放的波动比例为$ \ sqrt {\ langle {l _ {\ perp}^2}^2} \ rangle}/{l} \ sim（l} \ sim（l/\ ell_p） （$ν_{2D} = 0.75 $，$ν_{3D} = 0.58 $）。当将EV颗粒添加到系统中时，我们的结果表明，拥挤密度不会或仅对普遍缩放关系产生弱影响。我们通过将DsDNA的实验结果显示到主图上，讨论这些结果在生命物质中的含义。
We study universal aspects of polymer conformations and transverse fluctuations for a single swollen chain characterized by a contour length $L$ and a persistence length $\ell_p$ in two dimensions (2D) and in three dimensions (3D) in the bulk, as well as in the presence of excluded volume (EV) particles of different sizes occupying different volume fractions. In the absence of the EV particles we extend the previously established universal scaling relations in 2D (A. Huang, A. Bhattacharya, and K. Binder, J. Chem. 140, 214902 (2014)) to include 3D and demonstrate that the scaled end-to-end distance $\langle R_N^2\rangle/(2 L\ell_p)$ and the scaled transverse fluctuation $\sqrt{\langle{l_{\perp}^2}\rangle}/{L}$ as a function of $L/\ell_p$ collapse onto the same master curve, where $\langle R_N^2\rangle$ and $\langle{l_{\perp}^2\rangle}$ are the mean-square end-to-end distance and transverse fluctuations. However, unlike in 2D, where the Gaussian regime is absent due to extreme dominance of the EV interaction, we find the Gaussian regime is present, albeit very narrow in 3D. The scaled transverse fluctuation in the limit $L/\ell_p \ll 1$ is independent of the physical dimension and scales as $\sqrt{\langle{l_{\perp}^2}\rangle}/{L} \sim (L/\ell_p)^{ζ-1}$, where $ζ= 1.5$ is the roughening exponent. For $L/\ell_p \gg 1$ the scaled fluctuation scales as $\sqrt{\langle{l_{\perp}^2}\rangle}/{L} \sim (L/\ell_p)^{ν-1}$, where $ν$ is Flory exponent for the corresponding spatial dimension ($ν_{2D}=0.75$, and $ν_{3D}=0.58$). When EV particles are added into the system, our results indicate that the crowding density either does not or only weakly affects the universal scaling relations. We discuss the implications of these results in living matter by showing the experimental result for a dsDNA onto the master plot.
