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Physical Sciences and Mathematics Commons

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Selected Works

Prof. Stephanie Tristram-Nagle Ph.D.

Magnetic Resonance Spectroscopy

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Structure Of Lipid Bilayers, John Nagle, Stephanie Tristram-Nagle Aug 2014

Structure Of Lipid Bilayers, John Nagle, Stephanie Tristram-Nagle

Prof. Stephanie Tristram-Nagle Ph.D.

The quantitative experimental uncertainty in the structure of fully hydrated, biologically relevant, fluid (L(alpha)) phase lipid bilayers has been too large to provide a firm base for applications or for comparison with simulations. Many structural methods are reviewed including modern liquid crystallography of lipid bilayers that deals with the fully developed undulation fluctuations that occur in the L(alpha) phase. These fluctuations degrade the higher order diffraction data in a way that, if unrecognized, leads to erroneous conclusions regarding bilayer structure. Diffraction measurements at high instrumental resolution provide a measure of these fluctuations. In addition to providing better structural determination, this …


Orientation Of Tie-Lines In The Phase Diagram Of Dopc/Dppc/Cholesterol Model Biomembranes., Pradeep Uppamoochikkal, Stephanie Tristram-Nagle, John Nagle Aug 2014

Orientation Of Tie-Lines In The Phase Diagram Of Dopc/Dppc/Cholesterol Model Biomembranes., Pradeep Uppamoochikkal, Stephanie Tristram-Nagle, John Nagle

Prof. Stephanie Tristram-Nagle Ph.D.

We report the direction of tie-lines of coexisting phases in a ternary diagram of DOPC/DPPC/cholesterol lipid bilayers, which has been a system of interest in the discussion of biological rafts. For coexisting Ld and Lo phases, we find that the orientation angle α of the tie-lines increases as the cholesterol concentration increases and it also increases as temperature increases from T = 15 °C to T = 30 °C. Results at lower cholesterol concentrations support the existence of a different two-phase coexistence region of Ld and So phases and the existence of a three-phase region separating the two two-phase regions. …