Hofmann Werner, Winkler-Heil Renate, Balásházy Imre
Division of Physics and Biophysics, Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
Inhal Toxicol. 2006 Sep;18(10):809-19. doi: 10.1080/08958370600753851.
Deposition fractions in human airway generations were computed with a stochastic deposition model, which is based on a randomly, asymmetrically dividing lung morphology, applying Monte Carlo techniques. Corresponding uncorrelated surface deposition densities were obtained by dividing the average deposition fraction in a given generation by the average total surface area of that generation. In order to consider the statistical correlation between deposition probability and linear airway dimensions in each airway, correlated surface deposition densities were calculated by dividing the deposition fraction in a randomly selected bronchial or acinar airway by the surface area of that airway and by the total number of bronchial or acinar airways in that generation. Average surface deposition densities are relatively constant throughout bronchial airway generations, while average acinar surface deposition densities exhibit a distinct decrease with rising penetration into the acinar region. Due to the correlation between deposition fraction and surface area in a given airway generation, average correlated surface deposition densities are consistently higher than average uncorrelated densities, particularly in the acinar region, where differences can be as high as a few orders of magnitude. Already significant statistical fluctuations of the deposition fractions in individual airway generations are even exacerbated for surface deposition densities, with coefficients of variation about twice as high as for correlated deposition fractions.
使用基于随机、不对称划分肺形态的随机沉积模型，应用蒙特卡罗技术计算人类气道各级的沉积分数。通过将给定级别的平均沉积分数除以该级别的平均总表面积，获得相应的不相关表面沉积密度。为了考虑每个气道中沉积概率与线性气道尺寸之间的统计相关性，通过将随机选择的支气管或腺泡气道中的沉积分数除以该气道的表面积以及该级别的支气管或腺泡气道总数，计算相关表面沉积密度。在整个支气管气道各级中，平均表面沉积密度相对恒定，而平均腺泡表面沉积密度随着向腺泡区域的深入而明显降低。由于给定气道级别中沉积分数与表面积之间的相关性，平均相关表面沉积密度始终高于平均不相关密度，特别是在腺泡区域，差异可能高达几个数量级。对于表面沉积密度，单个气道级别中沉积分数已经存在的显著统计波动甚至会加剧，变异系数约为相关沉积分数的两倍。
