The respreading of a lung surfactant monolayer at the air-water interface is investigated with broad bandwidth sum frequency generation (BBSFG) spectroscopy. The lung surfactant mixture contains chain perdeuterated dipalmitoylphosphatidylcholine (DPPC-d62), palmitoyloleoylphosphatidylglycerol (POPG), palmitic acid (PA), and KL4 (a 21-residue polypeptide analogue to the surfactant protein SP-B)....

At the air-water interface, interfacial molecular structure, intermolecular interactions, film relaxation and film respreading of model lung surfactant monolayers were studied using vibrational sum frequency generation (VSFG) spectroscopy combined with a Langmuir film balance. Chain-perdeuterated dipalmitoylphosphatidylcholine (DPPC-d62), palmitoyloleoyl-phosphatidylglycerol (POPG), palmitic ac...

In recent years there has been a growing interest in macro models with heterogeneity in information and complementarity in actions. These models deliver promising positive properties, such as heightened inertia and volatility. But they also raise important normative questions, such as whether the heightened inertia and volatility are socially undesirable, whether there is room for policies that...

A thermodynamic study of monolayer mixing behavior was performed using binary lipid mixtures of DPPC + DOPG (7:1 mol:mol) as well as a mixture containing the phosphocholine acyl chain perdeuterated analog of DPPC, DPPC-d62 (i.e. 7:1 mol:mol DPPC-d62 + DOPG). An analysis was performed on these isotherms that calculated the Helmholtz excess free energy of mixing to determine potential thermodynam...

Infrared reflection-absorption spectroscopy (IRRAS) in combination with isotopic substitution and a modified 2D IR correlation analysis procedure were used to study the dynamics of phospholipid acyl chain structure in both an ideal and a nonideal binary monolayer mixture spread at the air-water (A/W) interface. The ideal mixture consisted of a 1:2 molar ratio of 1,2-dipalmitoyl-sn-glycero-3-pho...

Article history: Received 10 August 2011 Available online 13 April 2014 JEL classification: C72 C91 D62 D82 D83

The interaction between deuterated dipalmitoylphosphatidylcholine (DPPC-d62) and palmitic acid (PA) in mixed Langmuir monolayers is studied using vibrational sum frequency generation (VSFG) spectroscopy. Palmitic acid is an additive in exogenous lung surfactant preparations such as Survanta and Surfaxin. The effect of PA on the chain conformation and orientation of DPPC in the liquid-expanded a...

The role of lipid diversity in biomembranes is one of the major unsolved problems in biochemistry. One parameter of possible importance is the mean cross-sectional area occupied per lipid molecule, which may be related to formation of nonbilayer structures and membrane protein function. We have used 2H NMR spectroscopy to compare the properties of 1,2-diperdeuteriopalmitoyl-sn-glycero-3-phospho...