Cardiogenic mixing increases aerosol deposition in the human lung in the absence of gravity.
Cardiogenic mixing increases aerosol deposition in the human lung in the absence of gravity.
复制标题
在没有重力的情况下，心源性混合会增加人肺中的气溶胶沉积。
DOI：
10.1016/j.actaastro.2012.05.022
复制
发表时间：
2013
影响因子：
3.5
通讯作者：
Darquenne,Chantal
中科院分区：
文献类型：
--
作者：
Prisk,GKim;Sá,RuiCarlos;Darquenne,Chantal
暴露于地外尘埃几乎是任何行星探索计划的必然结果。以前对人类的研究表明，与正常重力（1G）相比，低重力下的沉积减少。然而，减少的沉降意味着气道中的颗粒存款更少，增加了输送到肺外周的颗粒数量，尽管以比1G中更小的速率，但颗粒最终在肺外周存款。在这项研究中，我们确定的作用，重力和其他机制，如心源性混合发挥外周肺沉积在breathholds.MethodsEight健康受试者吸入大剂量的0.5 μ m直径的颗粒，渗透体积（Vp）为300和1200毫升，随后由屏气长达10秒。在美国航天局微重力研究飞行器上进行了1G和短期微重力（μG）试验。从这些data.ResultsResults气溶胶沉积和分散计算结果表明，对于bothVp，沉积在1 G显着高于μG。相比之下，虽然在Vp =1200 ml时，1 G的分散度显著高于μG，但在Vp =300 ml时，重力对分散度没有显著影响。最后，对于每个G水平andVp，沉积和分散显着增加屏气time.ConclusionThe最重要的发现，这项研究是，即使在没有重力的情况下，气溶胶沉积在肺外周增加，增加停留时间。由于本研究中使用的颗粒太大而不受布朗扩散的显著影响，因此沉积的增加可能是由于心源性运动效应。
RationaleExposure to extraterrestrial dusts is an almost inevitable consequence of any proposed planetary exploration. Previous studies in humans showed reduced deposition in low-gravity compared with normal gravity (1 G). However, the reduced sedimentation means that fewer particles deposit in the airways, increasing the number of particles transported to the lung periphery where they eventually deposit albeit at a smaller rate than in 1 G. In this study, we determined the role that gravity and other mechanisms such as cardiogenic mixing play in peripheral lung deposition during breath holds.MethodsEight healthy subjects inhaled boluses of 0.5 μm-diameter particles to penetration volumes (Vp) of 300 and 1200 ml that were followed by breath holds of up to 10 s. Tests were performed in 1 G and during short periods of microgravity (μG) aboard the NASA Microgravity Research Aircraft. Aerosol deposition and dispersion were calculated from these data.ResultsResults show that, for bothVp, deposition in 1 G was significantly higher than inμG. In contrast, while dispersion was significantly higher in 1 G compared toμG atVp=1200 ml, there was no significant gravitational effect on dispersion atVp=300 ml. Finally, for each G level andVp, deposition and dispersion significantly increased with increasing breath-hold time.ConclusionThe most important finding of this study is that, even in the absence of gravity, aerosol deposition in the lung periphery increased with increasing residence time. Because the particles used in this study were too large to be significantly affected by Brownian diffusion, the increase in deposition is likely due to cardiogenic motion effects.