Fractional Brownian motion in crowded fluids
Fractional Brownian motion in crowded fluids
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DOI：
10.1039/c2sm25220a
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Weiss, Matthias
中科院分区：
文献类型：
--
作者：
Ernst, Dominique;Hellmann, Marcel;Weiss, Matthias
在拥挤的液体中的扩散，例如在活细胞的细胞质中的扩散，经常被报告显示出异常特征(所谓的亚扩散)。已经提出了几个随机行走模型来解释这些观察结果，但到目前为止，还没有一个实验支持的决定支持这些模型中的一个。在这里，我们表明，在典型的拥挤流体中，实验获得的轨迹显示出与分数布朗运动的预测最一致的非球面性，即与流体的粘弹性有关的正常布朗运动的反关联、反持续推广。
Diffusion in crowded fluids, e. g. in the cytoplasm of living cells, has frequently been reported to show anomalous characteristics (so-called 'subdiffusion'). Several random walk models have been proposed to explain these observations, yet so far an experimentally supported decision in favor of one of these models has been lacking. Here, we show that experimentally obtained trajectories in a prototypical crowded fluid show an asphericity that is most consistent with the predictions of fractional Brownian motion, i.e. an anti-correlated, anti-persistent generalization of normal Brownian motion that is related to the fluid's viscoelasticity.