CHAOTIC MIXING OF AEROSOL IN RHYTHMICALLY EXPANDING LUNG

描述(改编自申请人的摘要)：本研究的目标 是为了阐明大气中气溶胶沉积的潜在机制 肺腺泡，因为这一知识对于理解 呼吸系统疾病中的细小颗粒。目前的理论描述了气溶胶 在可逆腺泡流动的背景下表现为弥散过程，但是 实验观察表明，气溶胶在腺泡中的行为 不遵循这些理论预测的基本规则。因此，气雾剂 腺泡内沉积过程需要用新的理论重新解释 地面。最近，随着对切除的大鼠肺的流动可视化研究，直接 已经获得了实验证据，腺泡流动可以很高 不可逆的，表现出复杂而复杂的拉伸和折叠流动模式。 根据这些发现，我们推测肺内的气溶胶行为 外围由拉伸和折叠运动学控制，而不是色散运动学 流程。为了验证这一假设，提出了三项研究。(一)机制 控制由于拉伸和折叠运动学而导致的粒子沉积将是 深入调查。使用最先进的数值技术，效果 与多个鞍座的存在相关的腺泡流动不可逆性 点(存在于每个扩张的肺泡中)和气溶胶上的异步流 我们将对其进行研究。(2)这些个别人士的累积影响 肺泡流动现象对全球流动和气溶胶行为的影响 学习。(3)由此形成的全面的理论框架。 研究(1和2)将与动物实验进行对比测试。流动可视化 气雾剂暴露实验将在离体兔肺上进行。 在相同的条件下，将拉伸和折叠流型与 气溶胶沉积和团注行为的模式。这些研究将提供一个 为理解气溶胶的作用机制奠定了坚实的新基础 在肺周围的运输和沉积，因此在一个 在颗粒性呼吸系统疾病发病机制中的重要一步。

DESCRIPTION (Adapted from the applicant's abstract):The goal of this research is to elucidate the underlying mechanisms of aerosol deposition in the pulmonary acinus, as this knowledge is essential to understanding the role of fine particles in respiratory illnesses. Current theories describe aerosol behavior as a dispersive process in the context of reversible acinar flow, but experimental observations show that the behavior of aerosols in the acinus does not follow the basic rules predicted by these theories. Thus, the aerosol deposition process in the acinus needs to be reinterpreted on new theoretical grounds. Recently, with flow visualization studies in excised rat lungs, direct experimental evidence has been obtained that acinar flow can be highly irreversible, exhibiting complex and convoluted stretch-and-fold flow patterns. Based on these findings, it is hypothesized that aerosol behavior in the lung periphery is governed by stretch-and-fold kinematics, rather than dispersive processes. To test this hypothesis, three studies are proposed. (1) Mechanisms governing particle deposition due to stretch-and-fold kinematics will be investigated in depth. Using state of the art numerical techniques, the effects of acinar flow irreversibility associated with the presence of multiple saddle points (present in each expanding alveolus), and asynchronous flow on aerosol deposition will be studied. (2) The cumulative effects of these individual alveolar flow phenomena on the global flow and aerosol behavior will be studied. (3) The comprehensive theoretical framework emerging from these studies (1 and 2) will be tested against animal experiments. Flow visualization and aerosol exposure experiments will be performed on excised rabbit lungs under identical conditions to correlate stretch-and-fold flow patterns with patterns of aerosol deposition and bolus behavior. These studies will provide a solid new foundation to understanding the mechanisms involved in aerosol transport and deposition in the lung periphery, thus shedding light on an important step in the pathogenesis of particle-induced respiratory diseases.