Physical Sciences and Mathematics Commons^™

Quantum Dot Metrics For Preparative Chemistry And Fluorescence Applications, Yi Shen

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) are considered to be a promising candidate for bio-imaging and solar cells because of their extraordinary photo-physical properties. The ultimate goal of this dissertation is to design a reliable matrix and a reproducible method to prepare QDs-based biocompatible probe for fluorescence applications. Synthesis of quantum dots requires a large amount of ligands to improve the stability at high temperature. However, for further application and surface modification of QDs, excess ligands must be removed. In this dissertation, I will first describe using gel permeation chromatography (GPC) as a media to purify different types of QDs. A …

Characterization Of 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase (Dxr) From Vibrio Vulnificus, Nikita K. Ussin

Theses and Dissertations

Vibrio vulnificus, a gram-negative bacterium, is the leading cause of seafood-borne illnesses and mortality in the United States. Previous studies of bacterial pathogens have identified a metabolite essential to V. vulnificus growth and function. 1-deoxy-D-xylulose 5-phosphate reductoisomerase (Dxr) is an essential enzyme in the viability of many bacteria and catalyzes the rearrangement of 1-deoxy-D-xylulose 5-phosphate (Dxp) to 2-C-methylerythritol 4-phosphate (MEP) within the MEP pathway found in plants and bacteria. Previous studies have been conducted to characterize Dxr homologs from other pathogens including E. coli, M. tuberculosis, and P. falciparum. Information on the structural and enzymatic characteristics of Dxr from Vibrio …

The Development Of A Miniature Spatial Heterodyne Raman Spectrometer For Applications In Planetary Exploration And Other Extreme Environments, Patrick Doyle Barnett

Theses and Dissertations

Space exploration is arguably one of the most important endeavors our species has ever undertaken. Rapid advances in rocketry and robotics in recent years has allowed for positioning of complex scientific instruments on other planets with a precision that was previously thought impossible. This, along with the need for more sophisticated chemical measurements to achieve the goals of new, more ambitious missions and recent advances in in-situ and remote spectroscopic techniques, has led to a boom in the use of spectroscopic instruments for space exploration. However, future missions to the moons of Jupiter and Saturn, along with other planetary bodies …

Using Synthetic Lectins To Investigate Metastatic Potential In Colon Cancer, Erin E. Gatrone

Theses and Dissertations

Cancer is a disease that affects millions of people each year and it is well established that early diagnosis is a key factor towards improving survival rate, with that in mind there is a great need for better diagnostics. From the earliest onset of cancer, changes can be detected in the type and amount of carbohydrates expressed by the cancer cells, i.e., aberrant glycosylation. This process results in differing glycosylation patterns that can be used to detect cancer. Aberrant glycosylation can also greatly affect the potential of cancer cells to metastasize and can be used to stage the disease as …

Renewable Bio-Based Intermediates, Monomers And Polymeric Materials From Plant Oils, Liang Yuan

Theses and Dissertations

In the dissertation work, new chemical intermediates, monomers and thermoplastic polymers were derived from renewable soybean oil. Elastomers were further developed using monomers and polymers from soybean oil. The properties of these polymeric materials were characterized and discussed.

In Chapter 1, the overall background and recent development polymers from renewable biomass, especially plant oils, is introduced. Major research objectives of my doctoral research were described.

The first section of the dissertation, on the preparation of renewable intermediates, novel monomers and homopolymers, is provided in Chapter 2 and Chapter 3. In Chapter 2, amidation of soybean oil with amino alcohols was …

Materials Discovery By Crystal Growth: Synthesis, Structure Determination, Magnetic, And Optical Properties Of Complex Lanthanide Containing Oxides, Oxyhydroxides, And Oxyfluorides, Allison Marie Latshaw

Theses and Dissertations

Exploratory crystal growth is a versatile technique and one that can advance materials discovery. Through exploratory crystal growth, it is possible to synthesize many new materials that can have applications in many fields, including solid-state lighting. There exist many adaptations for exploratory crystal growth, including the use of alkali halide flux growth and hydroflux growth, both reported herein. By changing variants in these techniques like reactant ratios, temperature, reaction profile, and, most importantly here, the flux compositions, it is possible to change the products formed or fine tune reactions for product purity.

For solid-state lighting applications, compounds that adopt colorless …

Mass Spectrometry-Based Protein Profiling And Investigations Of Tgf-Ss1-Induced Epithelial-Mesenchymal Transition Signatures In Namru Murine Mammary Gland Epithelial Cells, Matsepo Ramaboli

Theses and Dissertations

Breast cancer is the second-most common cancer and the second-leading cause of cancer-related deaths in women. Despite advances in cancer early detection, prevention and treatment, breast cancer is still a major health challenge due to low survival caused by breast cancer metastasis. This warrants critical attention and intervention. From the proteomic standpoint, a protein-based multiplex system that provides large array of informative signals for cancer identification and prognosis is still limited. In this dissertation work, we developed two mass spectrometry-based strategies involving chemical biology tools for rapid protein fingerprinting of breast cancer cell lines, and for probing the O-linked N-acetylglucosamine …

Crystal Growth And Characterization Of Reduced Early Transition Metal Compounds Grown Via Hydrothermal And Molten Flux Methods, Anthony J. Cortese

Theses and Dissertations

Interest in new and facile ways to prepare early transition metal reduced oxides has recently been increasing. In the past difficult flux techniques involving vacuum furnaces, expensive metal tubing, complicated electrolytic reduction apparatuses, were used to achieve in situ reduction of fully oxidized transition metal precursors. Often times these techniques were coupled with use of a difficult flux, such as boric acid, which is hard to remove due to its insolubility in water at room temperature. These limitations can be circumvented in multiple ways, including carefully choosing a redox neutral flux, using evacuated fused silica tubes for reaction vessels, and …

The Role Of Ferric Oxide Particles As Sources And Sinks Of Reactive Oxygen Species During The Autoxidation Of Ferrous Iron, Shengnan Meng

Theses and Dissertations

The oxic portion of the biosphere is a metastable mixture of different oxidation states of carbon, sulfur and oxygen energetically poised from equilibrium by the net rate differentials between photosynthetic carbon fixation and its metabolic or abiotic oxidation. The direct reaction of dioxygen with reduced carbon or sulfur is spin forbidden and therefore kinetically slow, but ferric and ferrous iron species serve as catalysts for enabling their oxidation and therefore play critical roles in the environment. This thesis reports exploratory and hypothesis driven research that seeks a better understanding of the physical and chemical limitations on the effectiveness of iron …

Applications Of Disposable Pipette Technologies With Lc-Ms/Ms For Forensic And Clinical Analyses Of Biological Matrices, Kaylee R. Mastrianni

Theses and Dissertations

Efficiently hydrolyzing glucuronide metabolites is an important step in the analysis of drugs in urine. Amitriptyline and cyclobenzaprine are both tricyclic compounds with tertiary aliphatic amine groups that are subsequently metabolized to a less common form of glucuronide metabolite, quaternary ammonium linked glucuronides (N+- glucuronide). A collaborative study was conducted to investigate discrepancies in recoveries of these two commonly prescribed compounds in patient urine samples when hydrolyzed with different enzyme from four different commercially available β-glucuronidase sources.

Similarly, there is potential for 6-monoacetylmorphine to be converted to morphine during β-glucuronidase hydrolysis of urine samples. 6-monoacetylmorphine is a unique metabolite of …

Investigating Structure-Activity Relationships Of Sl11 To Develop A Better Prostate Cancer Diagnostic, Rong Huang

Theses and Dissertations

Prostate cancer is now the second leading cause of cancer death in American men. Since many of the diagnostics either have high false results or risky, it’s important to have better diagnostics and earlier diagnosis of prostate cancer. Aberrant glycosylation is a hallmark of cancer. When cancer occurs, aberrant glycosylation occurs, therefore, glycosylation patterns may provide information about different cancer types and metastatic potential. In order to study and use these glycosylation patterns, the boronic acid functionalized synthetic lectins that can interact with glycans have been developed. The work described here focuses on 1) the structure activities of synthetic lectins …

Physical Property Control In Core/Shell Inorganic Nanostructures For Fluorescence And Magnetic Targeting Applications, Stephen K. Roberts

Theses and Dissertations

Nanomaterials show immense promise for the future in numerous areas of application. Properties that are unique from the bulk material and are tunable allow for innovation in material design. This thesis will focus on controlling the physical properties of core/shell nanostructures to enhance the utility of the materials.

The first focus is on the impact of different solvent mixtures during the shell growth phase of SILAR based core/shell quantum dot synthesis is studied. Gaining insight into the mechanism for SILAR growth of core/shell nanoparticles allows improved synthetic yields and precursor binding, providing enhanced control to synthesis of core/shell nanoparticles. The …

Wide Field Measurements Using A Spatial Heterodyne Raman Spectrometer For Transmission Raman Spectroscopy And Standoff Detection, Kimberly A. Fessler

Theses and Dissertations

Our group recently developed a new type of Fourier transform Raman spectrometer, the spatial heterodyne Raman spectrometer (SHRS), for planetary exploration. The SHRS is a high spectral resolution, high throughput, compact dispersive interferometer, similar in design to a Michelson interferometer, where the mirrors are replaced by stationary diffraction gratings. The SHRS has no moving parts and does not require an entrance slit, making the throughput of the system orders of magnitude larger than a typical dispersive spectrometer. The wide field-of-view (FOV) of the SHRS enables wide area measurements without loss of sensitivity or spectral resolution and offers advantages such as …

Virus Particles Provide Nanotopographical Cues For Osteogenic Differentiation Of Mesenchymal Stem Cells, Kamolrat Metavarayuth

Theses and Dissertations

One key aspect of tissue engineering is to develop biomimetic scaffolding materials that can modulate the proliferation, self-renewal and differentiation of multipotent stem cells into different lineages. Bone marrow derived mesenchymal stem cells (BMSCs) can differentiate into several target cells such as osteoblasts, chondrocytes, adipocytes, and smooth muscle cells. BMSCs are commonly used for in vitro osteogenesis studies in bone tissue engineering field. However the mechanisms and signaling pathways that these cells use to recognize and response to biomaterial surface are still unclear. This dissertation focuses on investigating the effect of chemical and physical cues introduced by virus nanoparticles on …

Investigating Cross Talk Between The High And Low Iron Sensors In Saccharomyces Cerevisiae, John S. Hepburn

Theses and Dissertations

Iron is essential for nearly all life on earth. Cells must maintain sufficient levels of this important nutrient due its function as a central co-factor for many cellular processes. Although iron is extremely plentiful, its poor solubility requires specialized import. On the other side, too much iron inside the cell can lead to the generation of reactive oxygen species (ROS), which have deleterious effects on many cellular functions and have been implicated in a wide variety of diseases such as cancer and Alzheimer’s disease. Using the model eukaryote Saccharomyces cerevisiae, or budding yeast, our research group has accomplished much in …

Investigating The Effects Of Glutathione And Other Key Proteins On Iron Homeostasis And Subcellular Redox Balance In Yeast Model Systems, Kirsten Renee Collins

Theses and Dissertations

Iron homeostasis in Saccharomyces cerevisiae is controlled through several pathways and is important because too much iron can cause cellular damage. Iron homeostasis in yeast is primarily controlled by transcription factors Aft1 and Aft2 which bind to the iron regulon to induce iron uptake when iron levels are low. When iron levels are sufficient, Aft1 and Aft2 are bound and inhibited by monothiol glutaredoxins (Grxs) Grx3 and Grx4. These Grxs are also involved in iron trafficking in the cell and bind to and deliver iron-sulfur clusters to multiple proteins.

The first part of this thesis focuses on determining if excess …

Development Of Protein-Polymer Core-Shell Nanoparticles (Ppcs-Nps) As Efficient Vehicles To Deliver Therapeutic Agents Across Blood Brain Barrier (Bbb), Napat Tandikul

Theses and Dissertations

Blood Brain Barrier (BBB) plays a main role as selective barrier which controls and limits access of chemicals, molecules and therapeutic agents from blood to brain. The BBB endothelial cells are connected by Tight Junctions (TJs) which close intracellular spaces between the endothelial cells and block the free diffusion of substances, therefore many potential drugs for treating human brain diseases cannot reach the brain in sufficient concentration. Recently, many studies have thrown an interest in development of nanoparticles for delivering drugs and imaging agents across BBB. Our research group has developed protein-polymer core-shell nanoparticles (PPCS-NPs) which demonstrate great potential for …

Properties And Applications Of Self-Assembled Benzophenone Bis-Urea Macrocycles, Arthur Ariston Korous

Theses and Dissertations

Supramolecular chemistry is a vast multidisciplinary field with great potential and application. It is driven by one simple concept, the self-assembly of small building blocks into larger complex architectures without application of external force. This thesis highlights previous applications of supramolecular chemistry in addition to new potential properties and applications. Recently, the Shimizu group reported a self-assembled benzophenone bis-urea macrocycle (host 1) that facilitated the selective oxidation of an encapsulated alkene when UV-irradiated in an oxygen atmosphere to afford products that are typically observed in radical mediated reactions.1 Surprisingly, the host displayed a stable room temperature radical upon UV irradiation. …

From Model Systems To Real Catalysts: Bridging The Pressure And Materials Gaps, Audrey S. Duke

Theses and Dissertations

For decades a fundamental understanding of heterogeneous catalysts has been pursued for rational catalyst design using model systems under ultrahigh vacuum (UHV) conditions; however, there exist stark differences between the simplified models investigated under UHV and the industrial catalysts used at high pressures. To bridge these gaps, it becomes essential to utilize progressively more complex materials and to correlate their surface structure and activity using incrementally higher pressure techniques. In this work, both model Pt-Re catalysts and powdered metal-organic frameworks (MOFs) were studied using a suite of traditional UHV surface science techniques in addition to ambient pressure X-ray photoelectron spectroscopy …

Classification Of Natural Phytoplankton Populations With Fluorescence Excitation-Based Imaging Multivariate Optical Computing, Shawna Kathleen Tazik

Theses and Dissertations

Phytoplankton account for the majority of the primary productivity in the ocean and contribute significantly to the global carbon cycle through photosynthesis. A quantitative characterization of phytoplankton cell size and taxonomic composition is essential for understanding marine biogeochemical cycles, quantifying carbon export, and for predicting the ocean’s response to future climate change. Our labs have developed a new instrument for this purpose that combines fluorescence excitation spectroscopy with an all-optical approach to multivariate statistics called multivariate optical computing (MOC). The instrument, known as the Shipboard Streak Imaging Multivariate Optical Computing (SSIMOC) photometer, is a simple filter photometer that images the …

Synthesis And Utility Of Bis-Urea Macrocycles As Nanoreactors And As Ligands For Metal Organic Materials, Sahan R. Salpage

Theses and Dissertations

“Supramolecular chemistry” powered by non-covalent interactive forces forms the crux in the area of host-guest chemistry. Supramolecular assemblies often have different chemical and physical properties than that of its individual molecular entities and are used to develop novel functional materials. Our expertise involves making functional materials from macrocycles, which contain two urea groups and two rigid C shaped spacer groups. These individual macrocyclic components can self-assemble through hydrogen bonding and other non-covalent interactions to form porous supramolecular assemblies that can be used as confined reaction environments and as ligands to synthesize novel metal organic materials.

This dissertation focuses on studying …

Cdk8 And Cdk19 As Novel Regulators Of Bmp4 Induced Emt In Cancer, Anne Elizabeth Serrao

Theses and Dissertations

Bone morphogenetic protein 2/4 (BMP2/4), members of the transforming growth factor β (Tgf-β) superfamily, play a dichotomous role in the progression of cancers through cell growth suppression and the enhancement of tumorigenesis in a variety of cancers. Cyclin dependent kinase 8 (CDK8), a protein kinase that regulates gene transcription, is involved in a variety of cancers including breast and pancreatic cancers as well as in mediating BMP2 signaling via its canonical Smad1 pathway. Our studies show that BMP4 induced EMT signals primarily though Smad1 and that Yap1, a transcriptional co-activator, is necessary for BMP4 induced EMT. Using a highly specific …

Improved Systems For On-Site Raman Measurements, William Joshua Huntington

Theses and Dissertations

The need to development lightweight miniature sensors for spectrometers for use in hazardous environments such as war zones, industrial settings, and space exploration is ever growing. This thesis will present studies aimed at improving Raman instruments for such applications by reducing the size, weight, and power consumption of the instrument. The two methods described here include the utilization of a light emitting diode (LED) source for Raman spectroscopy and a new type of Raman gas sensor.

Chapter one describes a new Raman spectrometer that utilizes an LED for Raman excitation coupled to the SHRS. LEDs are highly divergent broadband , …

Ligand Engineering For Advanced Functional Composite Materials, Michael H. Bell

Theses and Dissertations

The surface modification of solid inorganic substrates for thermodynamic compatibility with organic polymer media has become an important area of study for the development of advanced functional composite materials. Polymer ligands covalently bound to the substrate surface have been an effective means to achieve said compatibility. Current investigations focus on multifunctional ligand engineering where multiple chemically distinct species, each with specific functionality, can be implemented on the filler surface simultaneously. A combination of matrix compatible polymer brushes and conjugated charge trapping moieties attached to filler surfaces are investigated for enhancements in dielectric properties. Presented herein are the synthesis and characterization …

Estimation Of The Quantum Effects Of Nuclei In Large Molecular Systems, Bing Gu

Theses and Dissertations

Chemical dynamics, in principle, should be understood by solving the time-dependent Schrödinger equation for a molecular system, describing motion of the nuclei and electrons. However, the computational efforts to solve this partial second-order differential equation scales exponentially with the system size, which prevents us from getting exact numerical solutions for systems larger than 4-5 atoms. Thus, approximations simplifying the picture are necessary. The so-called Born-Oppenheimer approximation, separating motion of the electrons and nuclei is the central one: solution to the electronic Schrödinger equation defines the potential energy surface on which the nuclear motion unfolds, and there are standard quantum chemistry …

Mechanistic Investigation And Potential Application Of A Fatty Acid Decarboxylating Cytochrome P450 Peroxygenase, Chun H. Hsieh

Theses and Dissertations

OleT (CYP152L1) is a recently discovered cytochrome P450 that is structurally similar to peroxide dependent P450s that catalyze fatty acid hydroxylations. OleT has been shown to catalyze the cleavage of n chain length fatty acids to form n-1 alkenes through C-C bond scission of the terminal carboxylate. Using headspace GC-MS and FTIR with isotopically labeled substrates, we have confirmed that OleT metabolizes eicosanoic acid to 1-nonadecene, forming carbon dioxide (CO2) as a co-product of the reaction. No oxygen deriving from peroxide is observed in either product. In order to probe the mechanistic deviation of OleT from P450 peroxygenases, we have …

Measurement Of Non-Covalent Aromatic Interactions Using Molecular Balances, Jung Wun Hwang

Theses and Dissertations

Non-covalent aromatic interactions govern many of the unique structures and properties of biological and synthetic molecules. Despite the importance of these interactions, their weak nature makes it challenging to study the interactions. To accurately measure weak non-covalent aromatic interactions in solution, we have designed molecular torsion balances that provide a quantitative measure of non-covalent intramolecular interaction strengths. First, we investigated the importance of electrostatic interactions in aromatic interactions. Substituent effects were strongly correlated with electrostatic Hammett parameters. In addition, the substituent effects were additive and showed significant direct substituent-arene interactions that support the recent direct substituent effect model. Next, the …

Synthesis Attempts And Plausible Applications Of Dithiolated Ortho –Carboranyl Transition Metal Complexes And Synthesis Of Bulky Terphenyls, Surendra Bahadur Karki

Theses and Dissertations

The reaction of coordination compounds of palladium, rhodium, ruthenium and nickel with thiolated ortho-carborane derivatives- 1,2-dimercapto-o-carborane (1,2-(HS)2-1,2- C2B10H10 ) and 9,12- dimercapto-o-carborane (9,12-(HS)2-1,2- C2B10H10 ) and with carbornanyl dicarboxylate has been studied. To further investigate the chemistry of o-carboranyl dithiolate, both of the reported literature dithiols have been employed to study the reactivity with some of the above mentioned transition metal coordination compounds. The 1,2-dimercapto-o-carborane reacts with bis(triphenylphosphine)palladium(II) chloride [PdCl2(PPh3)2] to form a square planar bis(triphenylphosphine)palladium(II) carboranyl dithiolate (PdC2B10S2(PPh3)2) complex. With the inspiration from the reactivity of the dithiols and versatility of carboranyldithiolate ligand in organometallic chemistry, new avenue of …

Development Of A Luminescent Polymer Sensor Array For The Discrimination Of Carboxylates And Further Improvements In A Solvent Programmable Polymer, William J. Richardson

Theses and Dissertations

This thesis summarizes the work performed on two stimuli responsive polymer projects. The first project used a lanthanide based luminescent polymer to create a sensor array for carboxylate analytes. Initial attempts incorporated molecular imprinting as a means to incorporate unique selectivity into the polymer by introducing acetate, benzoate, and phenylacetate as templates prior to polymerization. This process was successful at creating unique sensing elements for the array, but the polymers lacked the specific selectivity typically seen in molecularly imprinted polymers (MIPs). Instead, a ligand displacement mechanism that relied on multiple sensors with different labile anion ligands directly complexed with the …

Development Of Reactions And Methods For Labeling Biomolecules In Cells, Enoch Agbesi Adogla

Theses and Dissertations

The complexity of cellular environments presents a challenge to efforts at studying and elucidating biomolecules in cells. Covalent ligation of biomolecules with fluorescent molecules that have a reactive functional group that can react with a complementary functional group on biomolecules is one way that has been utilized to study biomolecules. It enables visualization and tracking of ligation and transportation of molecules within the cell. However, the myriad of functional groups within the cell makes achieving selectivity difficult. To circumvent this problem, reactions that do not interfere with biology have been developed. These reactions, referred to as bioorthogonal reactions must be …