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Full-Text Articles in Physical Sciences and Mathematics

A Comparison Of Boltzmann And Gibbs Definitions Of Microcanonical Entropy For Small Systems, Randall B. Shirts Dec 2012

A Comparison Of Boltzmann And Gibbs Definitions Of Microcanonical Entropy For Small Systems, Randall B. Shirts

Faculty Publications

Two different definitions of entropy, S= klnW, in the microcanonical ensemble have been competing for over 100 years. The Boltzmann/Planck definition is that W is the number of states accessible to the system at its energy E (also called the surface entropy). The Gibbs/Hertz definition is that W is the number of states of the system up to the energy E (also called the volume entropy). These two definitions agree for large systems but differ by terms of order N-1 for small systems, where N is the number of particles in the system. For three analytical …


Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge Dec 2012

Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge

Theses and Dissertations

Biomarkers present a non-invasive means of detecting cancer because they can be obtained from body fluids. They can also be used for prognosis and assessing response to treatment. To limit interferences it is essential to pretreat biological samples before analysis. Sample preparation methods include extraction of analyte from an unsuitable matrix, purification, concentration or dilution and labeling. The many advantages offered by microfluidics include portability, speed, automation and integration. Because of the difficulties encountered in integrating this step in microfluidic devices most sample preparation methods are often carried out off-chip. In the fabrication of micro-total analysis systems it is important …


Microfabrication, Characterization, And Application Of Carbon Nanotube Templated Thin Layer Chromatography Plates, And Functionalization Of Porous Graphitic Carbon, David S. Jensen Nov 2012

Microfabrication, Characterization, And Application Of Carbon Nanotube Templated Thin Layer Chromatography Plates, And Functionalization Of Porous Graphitic Carbon, David S. Jensen

Theses and Dissertations

This dissertation contains the following sections. Chapter 1 contains a detailed description of the theory of thin layer chromatography (TLC). Chapter 2 describes the benefits and practical considerations of elevated temperatures in liquid chromatography (LC). The porous graphitic carbon (PGC) I modified as part of my work is often used in elevated temperature LC. Chapter 3 shows a thermodynamic analysis of chromatographic retention at elevated temperature, and Chapter 4 contains a closer look at the van 't Hoff equation in LC and how it can be used in retention modeling. In Chapter 5, I describe a new procedure for microfabricating …


Deposition And Characterization Of Hydrophobic Coatings, Vipul Gupta Nov 2012

Deposition And Characterization Of Hydrophobic Coatings, Vipul Gupta

Theses and Dissertations

Hydrophobic coatings find application in various sectors of the economy including to electronics, textiles, optical devices, and in scientific and commercial equipment. These different applications demand that different hydrophobic coatings posses a range of properties that may include smoothness or roughness, thicknesses on the order of a monolayer or a micron, robustness or the ability to dissolve quickly, transparency or opacity, water resistance or water permeability, electrical conductivity, oleophobicity, etc. However, whatever the final/desired properties, deposition via dry-deposition processes offers significant advantages, including greater reproducibility, increased environmental friendliness, and cost effectiveness on an industrial scale. Herein I explore the chemical …


Mechanism Of Action Studies On A New Class Of Anticancer Nucleosides, Megan E. Browning Nov 2012

Mechanism Of Action Studies On A New Class Of Anticancer Nucleosides, Megan E. Browning

Theses and Dissertations

We have completed mechanism of action studies on a new class of anticancer nucleosides typified by a novel nucleoside discovered in our lab, MAP-870. In order to study the mechanism of MAP-870, several experiments were completed on a colorectal adenocarcinoma cell line, HT-29, including trypan blue cell count, sulforhodamine B assays, flow cytometry of cell cycle, propidium iodide incorporation, and phosphatidylserine externalization, Caspase-Glo3/7 assays, DNA fragmentation gel, cyclophilin A release gel, PAMPA, and confocal imaging. Sulforhodamine B assays show that MAP-870 does indeed cause growth inhibition and cell death in the model tested. PAMPA assays show that MAP-870 does not …


Gas Phase Characterization Of Supramolecules Using Cross-Sectional Areas By Fticr And Sustained Off-Resonance Irradiation Collision Induced Dissociation Techniques In A Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, Fan Yang Aug 2012

Gas Phase Characterization Of Supramolecules Using Cross-Sectional Areas By Fticr And Sustained Off-Resonance Irradiation Collision Induced Dissociation Techniques In A Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, Fan Yang

Theses and Dissertations

In my dissertation, I use a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR-MS) to investigate supramolecules. Cross-sectional areas by Fourier transform ICR (CRAFTI), a novel technique for measurements of collision cross sections by FTICR, is demonstrated for the first time. The CRAFTI method measures the total "dephasing cross section" for removal of the ions from the coherent packet in the FTICR cell, including contributions not only from momentum transfer but also from reactive collisions including those leading to collisional dissociation. Experimental CRAFTI collision cross sections correlate linearly with theoretically computed results and with results obtained using ion mobility measurements. …


Flow Valve Diagnostics For Label-Free, Quantitative Biomarker Detection: Device Fabrication, Surface Modification, And Testing, Danielle Scarlet Mansfield Aug 2012

Flow Valve Diagnostics For Label-Free, Quantitative Biomarker Detection: Device Fabrication, Surface Modification, And Testing, Danielle Scarlet Mansfield

Theses and Dissertations

Diseases are often diagnosed by detection of disease-specific biomarkers in fluid samples. However, many state-of-the-art detection methods require a lab with complex machinery, trained operators, and/or lengthy analysis time. In contrast, point-of-care (POC) devices are brought to the patient's location, they are easy to use, and results are obtained almost immediately. Many current POC devices are too difficult to be used without a skilled assistant, and although many are able to detect analytes above a threshold value, they give little or no quantitative information. This work presents the development of polymer-based microfluidic devices capable of sensing and quantifying biomarkers in …


Synthesis And Biological Evaluation Of Various Derivatives Of A Broad-Spectrum Anticancer Nucleoside, Jadd R. Shelton Aug 2012

Synthesis And Biological Evaluation Of Various Derivatives Of A Broad-Spectrum Anticancer Nucleoside, Jadd R. Shelton

Theses and Dissertations

Recently the Peterson lab discovered a promising anticancer adenosine derivative-- 2´,3´-bis-O-tert-butyldimethylsilyl-5´-deoxy-5´-[N-(methylcarbamoyl)amino]-N6-(N-phenylcarbamoyl)adenosine. This compound showed selective toxicity against human colon cancer cells in vitro with LC50's = 6--10 µM. It was hypothesized that the lead compound exerted its cytotoxic effects by interacting with a protein kinase. A systematic Structure Activity Relationship (SAR) was undertaken in an attempt to increase the kinase-binding affinity of the lead compound. Many regions of the lead compound were examined: the N6-phenyl urea moiety, the 5´-N-methyl urea group, the 2´,3´-bis-O-TBS groups, the nucleobase, and the ribose sugar. Results of these studies produced some promising new derivatives. In …


The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith Jul 2012

The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith

Theses and Dissertations

Nanotechnology is blossoming into one of the premiere technologies of this century, but the key to its progress lies in developing more efficient nanosynthesis methods. Variations in synthetic technique, however, can cause variations in size, structure, and surface characteristics, thereby altering the physical properties and functionality of the particles. Careful structural characterizations are thus essential for understanding the properties and appropriate applications for particles produced by new synthetic techniques.In this work, a new ‘solvent-deficient’ method is presented for the synthesis of an unprecedentedly wide range of metal oxide nanomaterials including at least one metal oxide from each group in Groups …


Refining Vibrationally-Resonant Sum Frequency Generation Spectroscopy For Studies Of Interfacial Interactions, Alexander D. Curtis May 2012

Refining Vibrationally-Resonant Sum Frequency Generation Spectroscopy For Studies Of Interfacial Interactions, Alexander D. Curtis

Theses and Dissertations

Many phenomena of interest to science and engineering occur at interfaces; however, access to, or discrimination of, interfacial interactions has been challenging, especially at buried interfaces. Vibrationally resonant sum-frequency generation (VR-SFG) spectroscopy is a powerful tool for investigating the molecular structure of free or buried interfaces, but spectral analysis has relied on many assumptions. To claim accurate new insights, practitioners must be able to make unique determinations from the data without experimental artifacts affecting the final results. For example, two independent and overlapping studies for the polystyrene/air interface were carried out, but reported different surface structures. Initially, this difference was …


Novel Phosducin-Like Protein Binding Partners: Exploring Chaperone And Tumor Suppressor Protein Interactions, Amy Jetaun Gray Mar 2012

Novel Phosducin-Like Protein Binding Partners: Exploring Chaperone And Tumor Suppressor Protein Interactions, Amy Jetaun Gray

Theses and Dissertations

Many proteins cannot fold into their native state without the assistance of one or more molecular chaperones. Chaperonins are an essential class of chaperones that provide an isolated chamber for proteins to fold. CCT, a group II chaperonin found in eukaryotes assists in the folding of actins, tubulins, and many other cellular proteins. PhLP1 is a member of the phosducin protein family that assists CCT in the folding of Gβ and its subsequent assembly with Gγ. However, previous studies have not addressed the scope of PhLP1 and CCT-mediated Gβγ; assembly. The data presented in Chapter 2 shows that PhLP1 plays …


Follicular Dendritic Cells, Human Immunodeficency Virus Type 1, And Alpha 1 Antitrypsin, Xueyuan Zhou Mar 2012

Follicular Dendritic Cells, Human Immunodeficency Virus Type 1, And Alpha 1 Antitrypsin, Xueyuan Zhou

Theses and Dissertations

HIV/AIDS is raging and causing millions of deaths around the world. The major challenge in treating HIV/AIDS is the establishment of HIV reservoirs where the viruse escapes both drug and immune system attempts at eradication. Throughout the course of HIV/AIDS, productive HIV infection occurs primarily in the lymphoid follicles or germinal centers (GC) surrounding follicular dendritic cells (FDC). In the GCs, FDCs trap and maintain infectious HIV for years and provide these infectious viruses to the host cells. FDCs also attract B and T cells into the GCs and increase the ability of CD4+ T cells to be infected. Additionally, …


Optical And Mass Spectrometric Studies Of A Helium Dielectric-Barrier Atmospheric-Pressure Plasma Jet Used As An Ambient Desorption Ionization Source, Matthew Spencer Heywood Mar 2012

Optical And Mass Spectrometric Studies Of A Helium Dielectric-Barrier Atmospheric-Pressure Plasma Jet Used As An Ambient Desorption Ionization Source, Matthew Spencer Heywood

Theses and Dissertations

Recently there has been a surge in the field of mass spectrometry centered around the concept of rapid analysis of target analytes with minimal or no sample preparation. The target analyte undergoes desorption from its surface of origin and is subsequently ionized under ambient conditions. The technique is termed ambient desorption/ionization mass spectrometry (ADI-MS). Since the introduction of ADI-MS in 2004, there has been an explosion of research based around the development of novel ambient desorption/ionization (ADI) sources with the capability of desorbing and ionizing a variety of target analytes from various sampling surfaces. One type of ADI source uses …


Dynamics Of The Solvent Exchange Reaction Of Weakly Bound Organic Solvents To Group 6 Transition Metal Carbonyls And The Molybdenum Hexacarbonyl Mediated Pauson-Khand Reaction, Richard J. Gates Feb 2012

Dynamics Of The Solvent Exchange Reaction Of Weakly Bound Organic Solvents To Group 6 Transition Metal Carbonyls And The Molybdenum Hexacarbonyl Mediated Pauson-Khand Reaction, Richard J. Gates

Theses and Dissertations

Many organometallic reactions are solvent-dependent, suggesting solvent molecules interact with reaction intermediates. Studies of the solvent exchange reaction of group 6 transition metal carbonyls with moderately binding ligands have provided insight into these interactions, however, studies of the mechanism for this reaction with weakly binding ligands have not been performed. Experiments were conducted on the nanosecond time scale in methylcyclohexane over the temperature range of 4 to 44 °C using Step Scan FTIR (SS FTIR) spectroscopy with weakly binding ligands benzene and mesitylene. Upon photolysis of the metal hexacarbonyls, the kinetically favored product (M(CO)5(solv)), decays following pseudo-first-order kinetics to the …