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ASU Electronic Theses and Dissertations


Contributor
Date Range
2011 2016

Calcitonin Gene-Related Peptide (CGRP) is an intrinsically disordered protein that has no regular secondary structure, but plays an important role in vasodilation and pain transmission in migraine. Little is known about the structure and dynamics of the monomeric state of CGRP or how CGRP is able to function in the cell, despite the lack of regular secondary structure. This work focuses characterizing the non-local structural and dynamical properties of the CGRP monomer in solution, and understanding how these are affected by the sequence and the solution environment. The unbound, free state of CGRP is measured using a nanosecond laser-pump spectrophotometer, ...

Contributors
Sizemore, Sara, Vaiana, Sara, Ghirlanda, Giovanna, et al.
Created Date
2015

CpG methylation is an essential requirement for the normal development of mammals, but aberrant changes in the methylation can lead to tumor progression and cancer. An in-depth understanding of this phenomenon can provide insights into the mechanism of gene repression. We present a study comparing methylated DNA and normal DNA wrt its persistence length and contour length. Although, previous experiments and studies show no difference between the physical properties of the two, the data collected and interpreted here gives a different picture to the methylation phenomena and its effect on gene silencing. The study was extended to the artificially reconstituted ...

Contributors
Kaur, Parminder, Lindsay, Stuart, Ros, Robert, et al.
Created Date
2012

Single molecule identification is one essential application area of nanotechnology. The application areas including DNA sequencing, peptide sequencing, early disease detection and other industrial applications such as quantitative and quantitative analysis of impurities, etc. The recognition tunneling technique we have developed shows that after functionalization of the probe and substrate of a conventional Scanning Tunneling Microscope with recognition molecules ("tethered molecule-pair" configuration), analyte molecules trapped in the gap that is formed by probe and substrate will bond with the reagent molecules. The stochastic bond formation/breakage fluctuations give insight into the nature of the intermolecular bonding at a single molecule-pair level. ...

Contributors
Zhao, Yanan, Lindsay, Stuart, Nemanich, Robert, et al.
Created Date
2014

Nanofluidic devices in which one single-walled carbon nanotube (SWCNT) spans a barrier between two fluid reservoirs were constructed, enabling direct electrical measurement of the transport of ions and molecules. Ion current through these devices is about 2 orders of magnitude larger than that predicted from the bulk resistivity of the electrolyte. Electroosmosis drives excess current, carried by cations, and is found to be the origin of giant ionic current through SWCNT as shown by building an ionic field-effect transistor with a gate electrode embedded in the fluid barrier. Wetting of inside of the semi-conducting SWCNT by water showed the change ...

Contributors
Pang, Pei, Lindsay, Stuart, Ros, Robert, et al.
Created Date
2011

An animal's ability to produce protein-based silk materials has evolved independently in many different arthropod lineages, satisfying various ecological necessities. However, regardless of their wide range of uses and their potential industrial and biomedical applications, advanced knowledge on the molecular structure of silk biopolymers is largely limited to those produced by spiders (order Araneae) and silkworms (order Lepidoptera). This thesis provides an in-depth molecular-level characterization of silk fibers produced by two vastly different insects: the caddisfly larvae (order Trichoptera) and the webspinner (order Embioptera). The molecular structure of caddisfly larval silk from the species <italic>Hesperophylax consimilis</italic> was characterized using solid-state ...

Contributors
Addison, John Bennett, Yarger, Jeffery L, Holland, Gregory P, et al.
Created Date
2014

Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode ("tethered molecule-pair" configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Importantly, at large tunnel gaps, there exists a regime for many molecules in which the tunneling is influenced more by the chemical identity of the molecules than by variability in the molecule-metal contact. Functionalizing a pair of electrodes with recognition reagents (the ...

Contributors
Chang, Shuai, Lindsay, Stuart, Ros, Robert, et al.
Created Date
2012

This thesis describes several experiments based on carbon nanotube nanofludic devices and field-effect transistors. The first experiment detected ion and molecule translocation through one single-walled carbon nanotube (SWCNT) that spans a barrier between two fluid reservoirs. The electrical ionic current is measured. Translocation of small single stranded DNA oligomers is marked by large transient increases in current through the tube and confirmed by a PCR (polymerase chain reaction) analysis. Carbon nanotubes simplify the construction of nanopores, permit new types of electrical measurement, and open new avenues for control of DNA translocation. The second experiment constructed devices in which the interior ...

Contributors
Cao, Di, Lindsay, Stuart, Vaiana, Sara, et al.
Created Date
2011

Richard Feynman said “There’s plenty of room at the bottom”. This inspired the techniques to improve the single molecule measurements. Since the first single molecule study was in 1961, it has been developed in various field and evolved into powerful tools to understand chemical and biological property of molecules. This thesis demonstrates electronic single molecule measurement with Scanning Tunneling Microscopy (STM) and two of applications of STM; Break Junction (BJ) and Recognition Tunneling (RT). First, the two series of carotenoid molecules with four different substituents were investigated to show how substituents relate to the conductance and molecular structure. The measured ...

Contributors
Im, JongOne, Lindsay, Stuart M, Zhang, Peiming, et al.
Created Date
2016

This dissertation features a compilation of studies concerning the biophysics of multicellular systems. I explore eukaryotic systems across length scales of the cell cytoskeleton to macroscopic scales of tissues. I begin with a general overview of the natural phenomena of life and a philosophy of investigating developmental systems in biology. The topics covered throughout this dissertation require a background in eukaryotic cell physiology, viscoelasticity, and processes of embryonic tissue morphogenesis. Following a brief background on these topics, I present an overview of the Subcellular Element Model (ScEM). This is a modeling framework which allows one to compute the dynamics of ...

Contributors
Sandersius, Sebastian Ambrose, Newman, Timothy J, Rez, Peter, et al.
Created Date
2011

Breast cancer cell invasion is a highly orchestrated process driven by a myriad of complex microenvironmental stimuli. These complexities make it difficult to isolate and assess the effects of specific parameters including matrix stiffness and tumor architecture on disease progression. In this regard, morphologically accurate tumor models are becoming instrumental to perform fundamental studies on cancer cell invasion within well-controlled conditions. In this study, the use of photocrosslinkable hydrogels and a novel, two-step photolithography technique was explored to microengineer a 3D breast tumor model. The microfabrication process presented herein enabled precise localization of the cells and creation of high stiffness ...

Contributors
Sam, Feba, Nikkhah, Mehdi, Ros, Robert, et al.
Created Date
2015

This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries.

For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.