Lateral diffusion in spin-labeled phosphatidylcholine multilayers.

Supported lipid bilayers are widely used as model systems due to their robustness. Due to the solid support, the properties of supported lipid bilayers are different from those of freestanding bilayers. In this article, we examine whether different surface treatments affect the properties of supported lipid bilayers. It will be shown that depending on the treatment method, the diffusion of the lipids can be adjusted approximately threefold without altering the composition. Additionally, as the bilayer-support interaction decreases, it becomes easier to form coexisting liquid-ordered and liquid-disordered domains. The physical/chemical alterations that result from the different treatment methods will be discussed.

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PubMed2007

An early example of evidence-based medicine: hypoxemia due to nitrous oxide.

Diffusion anoxia. By Bernard Raymond Fink. Anesthesiology 1955; 16:511-14. In 1955, Dr. Bernard Raymond Fink published his findings that described the mechanism by which hypoxemia occurred when nitrous oxide-oxygen anesthesia was discontinued and room air breathing commenced. Using an ear oximeter and brachial artery blood gases, he measured oxygen saturation in eight healthy patients who had received 75% nitrous oxide-25% oxygen for gynecologic surgery. He showed that oxygen saturation decreased from 5% to 10% and often reached a value below 90% when the patient began room air breathing after the nitrous oxide-oxygen was discontinued. The effect was seen over a 10-min period. He concluded that "anoxia arises because the outward diffusion of nitrous oxide lowers the alveolar partial pressure of oxygen." This phenomenon can become a causative factor of cardiac arrest in patients with impaired pulmonary or cardiac reserves.

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