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You searched for subject:(monovalent salt). Showing records 1 – 2 of 2 total matches.

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University of Southern California

1. Ho, Ming-Chak. Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers.

Degree: PhD, Physics, 2014, University of Southern California

Electroporation provides a controllable method to introduce foreign substances into living cells. It is widely used by researchers in cell biology and the medical field to manipulate biological systems at the cellular level. For decades, electroporation has been studied extensively through experiments and theoretical models, and electroporation‐based technologies have been improved substantially with these efforts. One of the issues in utilizing electroporation is the lack of understanding in the phenomenon’s molecular mechanism and the microscopic details, mainly due to the difficulty in the direct experimental observation of the nanosecond‐scale electropore formation process and the nanometer‐sized electropore structure. To overcome this issue, Molecular Dynamics (MD) simulation has become one of the major tools to study electroporation at the microscopic level. ❧ Recent advancements of high performance computing, such as the increase in processing power, developments in algorithms and parallelization, have improved the efficiency of MD simulation substantially. Due to these advancements, MD simulation has become a popular tool for studying systems that are composed of biomolecules. For nearly a decade of effort, MD simulation revealed many different aspects of electroporation and it provided a molecular description of the process. Using MD simulation, we are able to observe the events during the electropore formation and annihilation, as well as the transport processes of molecules through the electropore. In addition, MD simulation provides a platform to study the molecular structure of electropore, and the associated energetic. ❧ My dissertation is organized as the follows: Chapter 1 provides the motivation of this research by discussing the applications of electroporation‐based technology, electroporation experiments, and the existing continuum model that describes electroporation. Chapter 2 introduces the MD formalism, models, and various algorithms used in our MD simulation. I will also discuss some of the previous MD studies of electroporation and their significances at the end of Chapter 2. In Chapter 3, we will examine the dynamics of water bridge during different stages of electroporation, and delineate the role of water molecules in electroporation by comparing the lipid bilayer system with an artificial water‐vacuum‐water system. In Chapter 4, we will examine the steady state of an electropore in lipid bilayer and evaluate the pore conductance of ions. The pore conductance values obtained from the simulations can be compared with those obtained by experiments. In Chapter 5, we will examine the effects that monovalent ions impose on lipid bilayer and electropore formation. We will also examine the pore conductance of ions under various ion concentrations, and the PS translocation process. At the end, I will summarize the findings in our research and provide a short outlook on MD simulation in the study of electroporation. Advisors/Committee Members: Gundersen, Martin A. (Committee Chair), Vernier, Paul Thomas (Committee Member), Däppen, Werner (Committee Member), Dappen, Werner (Committee Member), Daeppen, Werner (Committee Member), Haas, Stephan W. (Committee Member), Malmstadt, Noah (Committee Member).

Subjects/Keywords: molecular dynamics; electropermeabilization; monovalent salt; cell membrane; electropore

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ho, M. (2014). Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/376394/rec/4198

Chicago Manual of Style (16th Edition):

Ho, Ming-Chak. “Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers.” 2014. Doctoral Dissertation, University of Southern California. Accessed April 22, 2019. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/376394/rec/4198.

MLA Handbook (7th Edition):

Ho, Ming-Chak. “Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers.” 2014. Web. 22 Apr 2019.

Vancouver:

Ho M. Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2019 Apr 22]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/376394/rec/4198.

Council of Science Editors:

Ho M. Molecular simulations of water and monovalent ion dynamics in the electroporation of phospholipid bilayers. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/376394/rec/4198

2. Easter, Nickolas J. Interfacial behavior of RNA-free MS2 bacteriophage particles.

Degree: MS, 0231, 2011, University of Illinois – Urbana-Champaign

The effect of genomic material on the effective surface charge a viral capsid was investigated in this study. The RNA of bacteriophage MS2 was removed and the empty capsid characterized and compared to intact MS2. Transmission electron microscopy was used to ensure that the MS2 capsid was intact and RNA removed. Electrophoretic mobility, aggregation kinetics and kinetics of deposition on silica surface were studied for these two nanoparticles. The isoelectric point of MS2 and RNA-free MS2 were found to be 3.4 and 3.2 respectively, found by varying pH at a constant ionic strength. The electrophoretic softness, found by varying ionic strength and constant pH, found that MS2 was 2.1 nm and that RNA-free MS2 was 1.6 nm, a slightly harder particle. Electrophoretic mobility results of these two particles are similar in solution containing Na+ or Ca2+ or Mg2+ up to ionic strength of 600 mM. Similar aggregation kinetics of MS2 and RNA-free MS2 measured by time-resolved dynamic light scattering at increasing ionic strengths of Na+, Ca2+ and Mg2+ cations were observed. No significant aggregation was observed for both types of particles in solutions containing up to 600 mM NaCl. Insignificant aggregation at high ionic strength suggests an important role of steric repulsion. Using a Quartz Crystal Microbalance, RNA-free MS2 attachment efficiency was found to be higher than MS2. This can be explained by more steric repulsion by the untreated MS2 particles. Similarity in electrophoretic mobility and aggregation of these two particles suggest that for non-magnetic nanoparticles, surface properties are dominant. Advisors/Committee Members: Nguyen, Thanh H. (advisor).

Subjects/Keywords: Aggregation kinetics; Aquatic system; Bacteriophage MS2; Deposition Kinetics; Divalent Salt; Electrostatic interactions; Empty Capsid; Monovalent Salt; Negative charge; Steric repulsion; Time-resolved dynamics

…attachment efficiencies for a given salt condition, be it monovalent or divalent. For example, at… …extreme stability against aggregation in the presence of high concentrations of monovalent… …particles onto a silica surface in the presence of monovalent (Na+) and divalent (… …Measurements EPM of MS2 and RNA-free MS2 in solution was measured over a wide range of monovalent and… …divalent salt concentrations (0.1 mM to 600 mM for Na+, and 0.1 mM to 200 7 mM for Ca2… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Easter, N. J. (2011). Interfacial behavior of RNA-free MS2 bacteriophage particles. (Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/24056

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Easter, Nickolas J. “Interfacial behavior of RNA-free MS2 bacteriophage particles.” 2011. Thesis, University of Illinois – Urbana-Champaign. Accessed April 22, 2019. http://hdl.handle.net/2142/24056.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Easter, Nickolas J. “Interfacial behavior of RNA-free MS2 bacteriophage particles.” 2011. Web. 22 Apr 2019.

Vancouver:

Easter NJ. Interfacial behavior of RNA-free MS2 bacteriophage particles. [Internet] [Thesis]. University of Illinois – Urbana-Champaign; 2011. [cited 2019 Apr 22]. Available from: http://hdl.handle.net/2142/24056.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Easter NJ. Interfacial behavior of RNA-free MS2 bacteriophage particles. [Thesis]. University of Illinois – Urbana-Champaign; 2011. Available from: http://hdl.handle.net/2142/24056

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.