Deposition patterns of cigarette smoke in human airways.
Deposition patterns of cigarette smoke in human airways.
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DOI：
10.1080/15298669291359249
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
T. Martonen
中科院分区：
文献类型：
--
作者：
T. Martonen
香烟烟雾在替代人体呼吸道系统中的实验沉积模式是非常不同的。颗粒沉积在可预测的、定义明确的形态区域增强；最具体地说，在分叉区内的隆起和沿管状呼吸道的后段。体内粘液纤毛运输机制的效率也在呼吸道分支处降低。优先颗粒沉积和清除受损的几何位置可以与临床观察的显示肺癌发病率增加的解剖位置相关。这些位置与当前仅模拟惯性碰撞、沉积和扩散等常见颗粒沉积过程的理论模型不兼容，而试图解释颗粒的吸湿性。此外，来自人体受试者暴露的数据表明，迄今未知的因素影响吸入香烟烟雾的分布。在这里，提出了一个新的数学模型，它解释了卷烟的烟雾沉积模式，包括分叉“热点”，根据组成和累积密度。卷烟主流烟气的行为与其颗粒和汽气相的物理化学参数有关，是两种不同效应的结果：(1)颗粒云运动和(2)汽气行为。在肺气道中，效应1最为显著。高粒子数ns约等于3×10(9)cm-3，质量Rho S约等于10(-4)g cm-3，烟雾的浓度决定了它的一团具有实体的动力学性质(上述效应1)，与单个组成粒子的空气动力学尺寸特征无关。这种运动可能会因烟雾的气相-气相密度的整体运动(如上图效果2)而加剧。
Experimental deposition patterns of cigarette smoke in surrogate human airway systems are very heterogeneous. Particle deposits are enhanced at predictable, well-defined morphological regions; most specifically, carinal ridges within bifurcation zones and along posterior sections of tubular airways. The efficiency of the mucociliary transport mechanism in vivo is also reduced at airway branchings. The geometrical sites of preferential particle deposition and impaired clearance can be correlated with clinically observed anatomical sites exhibiting increased incidences of bronchogenic carcinomas. These locations are not compatible with current theoretical models simulating only the usual particle deposition processes of inertial impaction, sedimentation, and diffusion, while intending to account for particle hygroscopicity. Moreover, data from human subject exposures indicate that heretofore unknown factors affect the distribution of inhaled cigarette smoke. Herein, a new mathematical model is presented that explains cigarette smoke deposition patterns, including bifurcation "hot spots," in terms of composition and cumulative density. The behavior of mainstream cigarette smoke can be related to physicochemical parameters of its particulate and vapor-gas phases and is a result of two distinct effects: (1) particle cloud motion and (2) vapor-gas behavior. In lung airways, Effect 1 is the most prominent. The high particle number,ns approximately equal to 3 x 10(9) cm-3, and mass,rho s approximately equal to 10(-4) g cm-3, concentrations of smoke dictate that a bolus of it has kinetic properties of an entity (Effect 1 above), independent of the aerodynamic size characteristics of individual constituent particles. This motion may be exacerbated by the bulk movement (Effect 2 above) of the vapor-gas phase density of smoke.