Effect of the compression ratio on properties of lung surfactant (bovine lipid extract surfactant) films
| Autor: | J.Y. Lu, K. Philips, A.W. Neumann, P. Chen, J. Distefano |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Pulmonary and Respiratory Medicine
Chromatography Time Factors Physiology Chemistry Bubble Pulmonary Surfactants Drop shape Compression (physics) Surface pressure Surface film Surface tension Pulmonary surfactant Compression ratio Image Processing Computer-Assisted Pressure Animals Surface Tension Cattle Adsorption Composite material |
| Zdroj: | Respiration physiology. 115(1) |
| ISSN: | 0034-5687 |
| Popis: | Using axisymmetric drop shape analysis (ADSA) and a captive bubble technique, the properties of lung surfactant (BLES) films under different compression ratios (i.e. the ratio of maximum to minimum surface area of the bubble) were investigated. In particular, the effect of the compression ratio of the films on the shape of the volume–area–surface tension–time (VAST) graphs and on the shape of the surface tension–relative area ( γ – A ) graphs was examined at the air–liquid interface. Under relatively low compression ratios of the films, the VAST and γ – A graphs indicate that the cycling is reversible (i.e. the γ – A graphs are identical for expansion and compression). When the compression ratio of the films increases, failure tends to occur when the surface film can not support the increasing surface pressure, causing a hysteresis loop in the γ – A graph. It was also found that low surface tension (i.e. below 5 mJ/m 2 ) at the interface could be attained with a 30% compression ratio and collapse of the films always occurs near or below 1 mJ/m 2 . |
| Databáze: | OpenAIRE |
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