Surfactant effects in model airway closure experiments
Surfactant effects in model airway closure experiments
复制标题
DOI：
10.1152/jappl.1999.87.1.415
复制
发表时间：
1999-07-01
影响因子：
3.3
通讯作者：
Grotberg, JB
中科院分区：
文献类型：
--
作者：
Cassidy, KJ;Halpern, D;Grotberg, JB
将管内衬环形薄膜上发生的毛细管不稳定性作为气道闭合模型进行研究。薄膜中的小波可以放大并在管子上形成堵塞。使用理论模型和台式实验研究了这种动态行为。我们的模型预测了不稳定性的初始增长率及其对表面活性剂效应的依赖性。在实验中，通过将水注入最初充满油的玻璃毛细管中来形成环形膜。油膜的厚度随输注流量的变化而变化。测量一系列薄膜厚度的不稳定性增长率和闭合时间。我们的理论预测，更薄的薄膜和更高的表面活性剂活性可以增强稳定性；表面活性剂可使增长率降低至不含表面活性剂值的 25%。在实验中，我们发现表面活性剂可以将增长率降低至20%，并将闭合时间延长3.8倍。闭合临界膜厚度的函数值支持这样的理论：在表面活性剂存在下膜厚度会增加。
The capillary instability that occurs on an annular film lining a tube is studied as a model of airway closure. Small waves in the film can amplify and form a plug across the tube. This dynamical behavior is studied using theoretical models and bench-top experiments. Our mo del predicts the initial growth rate of the instability and its dependence on surfactant effects. In experiments, an annular film is formed by infusion of water into an initially oil-filled glass capillary tube. The thickness of the oil film varies with the infusion flow rate. The instability growth rate and closure time are measured for a range of film thicknesses. Our theory predicts that a thinner film and higher surfactant activity enhance stability; surfactant can decrease the growth rate to 25% of its surfactant-free value. In experiments, we find that surfactant can decrease the growth rate to 20% and increase the closure time by a factor of 3.8. Functional values of a critical film thickness for closure support the theory that it increases in the presence of surfactant.