论文标题
手性诱导的细菌性风湿在散装剪切流中
Chirality-induced bacterial rheotaxis in bulk shear flows
论文作者
论文摘要
游泳细菌与流量的相互作用控制着探索复杂环境的能力，这对于许多社会和环境挑战至关重要，并且与微流体应用有关的细胞分类至关重要。结合了实验性，数值和理论分析，我们介绍了剪切流中运动细菌运输的全面研究。在实验上，我们以高精度和大量流速获得空间分辨率和方向分布。他们与对随机和微水动力学特性的运动模型的模拟非常吻合，尤其是鞭毛手性。理论分析揭示了使用手性参数在中等剪切速率下平均风湿性速度背后的缩放定律，并解释了从固定点的边际稳定性，导致在较大的剪切速率下饱和的重新定向动力学。我们的发现构成了对细菌大体鼻动物的物理机制和相关参数的充分理解。
Interaction of swimming bacteria with flows controls their ability to explore complex environments, crucial to many societal and environmental challenges and relevant for microfluidic applications as cell sorting. Combining experimental, numerical and theoretical analysis, we present a comprehensive study of the transport of motile bacteria in shear flows. Experimentally, we obtain with high accuracy and for a large range of flow rates, the spatially resolved velocity and orientation distributions. They are in excellent agreement with the simulations of a kinematic model accounting for stochastic and microhydrodynamic properties and in particular the flagella chirality. Theoretical analysis reveals the scaling laws behind the average rheotactic velocity at moderate shear rates using a chirality parameter and explains the reorientation dynamics leading to a saturation at large shear rates from the marginal stability of a fixed point. Our findings constitute a full understanding of the physical mechanisms and relevant parameters of bacteria bulk rheotaxis.
