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Publications

Check out our new lab website for an updated list of publications

* indicates corresponding author, † indicates equal first authors, PPostdoc/research associate, GGraduate student, UUndergraduate student in the Ashkar Lab

  • “Cinematic reflectometry using QIKR, the quite intense kinetics reflectometer”, J.F. Ankner*, R. Ashkar, J.F. Browning, ..., E.B. Watkins, and D. Wilson, Rev. Sci. Instrum. (2023).  Article
  • “Cholesterol Stiffening of Lipid Membranes and Drug Interactions: Insights from Neutron Spin Echo and Deuterium NMR Spectroscopy”, PS. Gupta†, F.T. Doole†, GT. Kumarage, M. Doktorova, G. Khelashvili, R. Ashkar*,  M.F. Brown*, Invited Chapter in the book titled Cholesterol, edited by Alex Dopico and Anna Bukiya (Elsevier 2022).  Invited Article
  • “Molecular Mechanisms of Spontaneous Curvature and Softening in Complex Lipid Bilayer Mixtures”, H. J. Lessen, K. C. Sapp, A. H. Beaven, R. Ashkar, A. J. Sodt*. Biophys. J. (2022). Article
  • "Cholesterol Stiffening of Lipid Membranes", F.T. Doole, GT. Kumarage, R. Ashkar*, M.F. Brown*, J. Membr. Biol. (2022). Topical Review
  • "Molecular Simulations and NMR Reveal How Lipid Fluctuations Affect Membrane Mechanics", M. Doktorova*, G. Khelashvili, R. Ashkar, M. Brown*, Biophys. J. (2022). Article
  • "EXPANSE: A time-of-flight EXPanded Angle Neutron Spin Echo spectrometer at the Second Target Station of the Spallation Neutron Source", C. Do*, R. Ashkar, C. Boone, ..., D. Wilson, Y Z, Rev. Sci. Inst. (2022). Article
  • "Comparison of Bulk- vs Layer-by-Layer-Cured Stimuli-Responsive PNIPAM–Alginate Hydrogel Dynamic Viscoelastic Property Response via Embedded Sensors", Y. Liu, K. Bethel, M. Singh, J. Zhang, R. Ashkar, E. M. Davis, B. N. Johnson*, ACS Appl. Polym. Mater. (2022). Article
  • "Neutron Scattering Studies of Nanoscale Polymer-Based Coatings", GH. Rahmaninejad and R. Ashkar*, accepted for publication in the book titled Polymer Based Nanoscale Materials For Surface Coating, edited by Sabu Thomas and Susan George (Elsevier).
  • "The Dynamic Face of Lipid Membranes", PS. Gupta and R. Ashkar*, Soft Matter (2021). Invited Review in the 2021 Soft Matter Emerging Investigators themed collection
  • "Neutron Spin Echo Spectroscopy: A Unique Probe for Lipid Membrane Dynamics and Membrane-Protein Interactions", GT. Kumarage†, UJ. Nguyen† and R. Ashkar*, J. Vis. Exp. (2021). Invited Paper 
  • "The Universal Stiffening Effects of Cholesterol on Lipid Membranes", R. Ashkar*, M. Doktorova, F. A. Heberle, H. L. Scott, F. N. Barrera, J. Katsaras, G. Khelashvili, and M. F. Brown*,  Proc. Natl. Acad. Sci. (2021). Invited Letter
  • “Biomembrane Structure and Material Properties Studied with Neutron Scattering", J. Kinnun*, H.L. Scott*, R. Ashkar*, and J. Katsaras*, Front. Chem. (2021). Invited Review
  • “Scaling relationships for the elastic moduli and viscosity of mixed lipid membranes”, E.G. Kelley*, P. Butler, R. Ashkar, R. Bradbury, and M. Nagao, Proc. Natl. Acad. Sci. (2020). Article 
  • “How Cholesterol Stiffens Unsaturated Lipid Membranes”, PS. Chakraborty, M. Doktorova, T.R. Molugu, F.A. Heberle, H.L. Scott, B. Dzikovski, M. Nagao, L.-R. Stingaciu, R.F. Standaert, F. Barrera, J. Katsaras, G. Khelashvili, M.F. Brown*, and R. Ashkar*, Proc. Natl. Acad. Sci. (2020). Article 
  • “Selective dynamics in polymeric materials: Insights from quasi-elastic neutron scattering Spectroscopy”, R. Ashkar*, J. Appl. Phys. (2020). Invited Tutorial & Featured Article 
  • “Profile retrieval of a buried periodic structure using spin echo grazing incidence neutron scattering”, R. Ashkar*, R.M. Dalgliesh, R. Pynn, A.D.F. Dunbar, R.A.L. Jones, and A.J. Parnell*, Appl. Phys. Lett. (2020). Article 
  • “The Influence of Curvature on Domain Distribution in Binary Mixture Membranes”, W. Li, J. M. Carrillo*, J. Katsaras, B. Sumpter, R. Ashkar*, and R. Kumar*, Soft Matter 2019. Article & Back Cover 
  • "Neutron scattering in the biological sciences: progress and prospects", R. Ashkar, H.Z. Bilheux, H. Bordallo, R. Briber, D.J.E. Callaway, X. Cheng, . . . J.C. Smith. Acta Cryst. D74 1129-1168 74, 1129-1168. Lead Article
  • "Quantification of Carbon Nanotube Liquid Crystal Morphology via Neutron Scattering", Francesca Mirri, Rana Ashkar, Vida Jamali, Lucy Liberman, Robert A. Pinnick, Paul van der Schoot, Yeshayahu Talmon, Paul D. Butler, Matteo Pasquali Macromolecules 2018 51 (17), 6892-6900. Article
  • "Conformational Change and Suppression of the Θ-temperature for Solutions of Polymer-grafted Nanoparticles", K. I. S. Mongcopa, R. Poling-Skutvik, R. Ashkar, P. Butler, and R. Krishnamoorti. Soft Matter. 14, 6102-6108. Article
  • "Flexible Approach to Vibrational Sum-Frequency Generation Using Shaped Near-Infrared Light", A. U. Chowdhury, F. Liu, B. R. Watson, R. Ashkar, J. Katsaras, C. Patrick Collier, D. A. Lutterman, Y-Z Ma, T. R. Calhoun, and B. Doughty. Opt. Lett. 43, 2038-2041. Article
  • "Grating-Based Holographic Diffraction Methods for X-Rays and Neutrons: Phase Object Approximation and Dynamical Theory", H. Feng, R. Ashkar, N. Steinke, R. Dalgliesh, N.V. Lavrik, I. I. Kravchenko, and R. Pynn. J. Appl. Cryst. 51, 68-75. Article  
  • “Probing Elastic and Viscous Properties of Phospholipid Bilayers Using Neutron Spin Echo Spectroscopy”, M. Nagao*, E. G. Kelley, R. Ashkar, R. Bradbury, and P. D. Butler, J. Phys. Chem. Lett. 8 (19), 4679-4684. Article
  • “Rapid Large-Scale Assembly and Pattern Transfer of One-Dimensional Gold Nanorod Superstructures”, *R. Ashkar, *M. J. A. Hore, X. Ye, B. Natarajan, N. J. Greybush, T. Lam, C. R. Kagan, C. B. Murray, ACS Appl. Mater. Interfaces. 9 (30), 25513-25521. Article
  • “A Computational Approach to Model Neutron Scattering Data from Lipid Bilayers”, *J. M. Carrillo, J. Katsaras, B. Sumpter, and *R. Ashkar, J. Chem. Theory Comput. 13 (2), 916-925.  Article
  • “Unlocking the secrets of cell membranes”, R. Ashkar, Editorial, ACM SIGCAS Computers and Society Newsletter. 46 (2),  5-8. Article
  • “Multiscale metrologies for process optimization of carbon nanotube polymer composites”, B. Natarajan, N. Orloff, R. Ashkar, S. Doshi, K. Twedt, A. Krishnamurthy, C. Davis, A. M. Forster, E. Thostenson, J. Obrzut, R. Sharma, and J. A. Liddle*, Carbon. 108, 381- 393. Article
  • “Graphene nanocomposites with high molecular weight poly(ε-caprolactone) grafts: Controlled synthesis and accelerated crystallization”, †Titash Mondal, †R. Ashkar, P. Butler, A. Bhowmick* and Ramanan Krishnamoorti*, ACS Macro Lett. 5 (3), 278-282. Article
  • “Lightweight, flexible, high-performance carbon nanotube cables made by scalable flow coating”, Francesca Mirri, Nathan D. Orloff, R. Ashkar, A. Forster, C. Long, A. Bengio, A. Choi, Y. Luo, A. Hight Walker, P. Butler,  K. Migler, and M. Pasquali*, ACS Appl. Mater. Interfaces. 8 (7), 4903-4910. Article
  • “Wetting-dewetting and dispersion-aggregation transitions are distinct for polymer grafted nanoparticles in chemically dissimilar polymer matrix”, †T. B. Martin, † K. I. Mongcopa, R. Ashkar, P. Butler, R. Krishnamoorti*, and Arthi Jayaraman*, J. Am. Chem. Soc. 137 (33), 10624-10631. Article
  • “Tuning membrane thickness fluctuations in model lipid bilayers”, R. Ashkar, Michihiro Nagao*, P. Butler, A. Woodka, M. K. Sen and T. Koga, Biophys. J. 109 (1), 106-112. Article
  • “Thermoresponsive PNIPAM coatings on nanostructured gratings for cell alignment and release”, †M. Zhernenkov*, †R. Ashkar*, H. Feng, O. Akintewe, N. D. Gallant, R. Toomey, J. F. Ankner, and R. Pynn, ACS Appl. Mater. Interfaces. 7 (22). 11857-11862. Article
  • “Kinetic polymer arrest in percolated SWNT networks”, R. Ashkar*, M. Abdulbaki, M. Tyagi, A. Faraone, P. Butler and R. Krishnamoorti*, ACS Macro Lett. 3 (12). 1262-1265. Article
  • “A new approach for probing matter in periodic nanoconfinements using neutron scattering”, R. Ashkar*, R. Pynn, R. Dalgliesh, N. Lavrick, and I. Kravchenko. J. Appl. Cryst. 47. 1367-1373. Article
  • “Dynamical Theory: Application to spin echo resolved grazing incidence scattering from periodic structures”, R. Ashkar*, W.L. Schaich, V. O. de Haan, A.A. van Well, R. Dalgliesh, J. Plomp, R. Pynn*. J. Appl. Phys. 110 (10). Article
  • “Comparison of dynamical theory and phase-object approximation on neutron scattering from periodic structures”, *R. Ashkar, V. O. de Haan, A.A. vanWell, R. Dalgliesh, J. Plomp, W.L. Schaich, and R. Pynn. J. Appl. Cryst. 44. 958-965. Article
  • “Dynamical theory calculations of spin echo resolved grazing-incidence scattering from a diffraction grating”, R. Ashkar*, P. Stonaha, A. L.Washington, V. R. Shah, M. R. Fitzsimmons, B. Maranville, C. F. Majkrzak, W. T. Lee, W. L. Schaich, and R. Pynn*, J. Appl. Cryst. 43. 455- 465. Article