Chemistry Commons^™

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 …

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 …

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 , …

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 …

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 …

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 …

Novel Approaches To Investigate The Oxidation Rate Of Fe(Ii) And The Role Of Fe(Ii)/Fe(Iii) Cycling On The Maintenance Of Reactive Oxygen Species In Aquatic Systems, Justin Maurice Copeland

Theses and Dissertations

The biogeochemical cycling of iron, oxygen, and organic carbon are inextricably linked through the intermediacy of Reactive Oxygen Species (ROS) brought about by the autoxidation of ferrous iron (Fe(II)). This dissertation presents laboratory and field-based studies to investigate the kinetics of Fe(II) oxidation and its role in the production of ROS at oxic/anoxic interfaces. The net oxidation of Fe(II) in natural waters is a complex process consisting of alternating cycles of Fe(II) oxidation and Fe(III) reduction processes that are ultimately terminated via precipitation as insoluble Fe(III) (oxy)hydroxides. This complicates kinetic measurements of individual reaction steps in the process.

A critical …

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 …

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 …

Surface Chemistry And Transport Properties Of Ii-Vi Semiconductor Nanowires, Pravin Paudel

Theses and Dissertations

Semiconductor nanowires have been widely studied due to their unique properties such as width comparable to critical length-scales, high aspect ratio, and high carrier mobility. These unique properties make them a suitable candidate for various optical and electronic devices like photovoltaics, photodetectors, and field effect transistors. The nanowire surface plays an important role in the performance of these devices because of their high surface to volume ratio. The larger surface area of nanowires may provide better charge separation than planar heterostructures in photovoltaics by providing shorter distance to move for carrier before separation, however, presence of surface states may lead …

Chemometric Curve Resolution For Quantitative Liquid Chromatographic Analysis, Daniel W. Cook

Theses and Dissertations

In chemical analyses, it is crucial to distinguish between chemical species. This is often accomplished via chromatographic separations. These separations are often pushed to their limits in terms of the number of analytes that can be sufficiently resolved from one another, particularly when a quantitative analysis of these compounds is needed. Very often, complicated methods or new technology is required to provide adequate separation of samples arising from a variety of fields such as metabolomics, environmental science, food analysis, etc.

An often overlooked means for improving analysis is the use of chemometric data analysis techniques. Particularly, the use of chemometric …

Probing Allosteric, Partial Inhibition Of Thrombin Using Novel Anticoagulants, Stephen S. Verespy Iii

Theses and Dissertations

Thrombin is the key protease that regulates hemostasis; the delicate balance between procoagulation and anticoagulation of blood. In clotting disorders, like deep vein thrombosis or pulmonary embolism, procoagulation is up-regulated, but propagation of clotting can be inhibited with drugs targeting the proteases involved, like thrombin. Such drugs however, have serious side effects (e.g., excessive bleeding) and some require monitoring during the course of treatment. The reason for these side effects is the mechanism by which the drugs’ act. The two major mechanisms are direct orthosteric and indirect allosteric inhibition, which will completely abolish the protease’s activity. Herein we sought an …

Versatile Synthesis Of Transition Metal Phosphides: Emerging Front-Runners For Affordable Catalysis, April C. Mattei

Theses and Dissertations

Transition metal phosphide materials have found themselves at the forefront of research revolving around energy applications. Due to the vast range of properties possessed by marginally different phase compositions, binary and ternary metal phosphides are utilized as catalysts, semi-conductors and magnetocaloric materials along with many others. These attractive properties, which are highly phase dependent, call for a versatile and cost effective synthesis route for various phosphide materials without sacrificing properties important at the nanoscale such as particle size and morphology.

The primary focus outlined in the work of this dissertation pertains to a versatile wet chemical synthesis capable of producing …

Fabrication Of Multifunctional Nanostructured Porous Materials, Ahmed A. Farghaly

Theses and Dissertations

Nanostructured porous materials generally, and nanoporous noble metals specifically, have received considerable attention due to their superior chemical and physical properties over nanoparticles and bulk counterparts. This dissertation work aims to develop well-established strategies for the preparation of multifunctional nanostructured porous materials based on the combination of inorganic-chemistry, organic-chemistry and electrochemistry. The preparation strategies involved one or more of the following processes: sol-gel synthesis, co-electrodeposition, metal ions reduction, electropolymerization and dealloying or chemical etching. The study did not stop at the preparation limits but extended to investigate the reaction mechanism behind the formation of these multifunctional nanoporous structures in order …

Interactions Of The Naphthalene Radical Cation With Polar And Unsaturated Molecules In The Gas Phase, Sean P. Platt

Theses and Dissertations

Characterizing the interactions of solvent molecules with ions is fundamental in understanding the thermodynamics of solution chemistry. These interactions are difficult to observe directly in solution because the number of solvent molecules far exceed that of ions. This lend the gas phase to be the ideal medium in the study ion-solvent interactions on a molecular level. Ionized polycyclic aromatic hydrocarbon (PAH) molecules can readily form hydrogen bonds with neutral solvent molecules in aqueous and interstellar medium. Previous research has been done for stepwise solvation of small molecules such as benzene⁺, pyridine, and phenylacetylene. The similarity in these results …

Systematic Postsynthetic Modification Of Nanoporous Organic Frameworks And Their Performance Evaluation For Selective Co2 Capture, Timur Islamoglu

Theses and Dissertations

Porous organic polymers (POPs) with high physicochemical stability have attracted significant attention from the scientific community as promising platforms for small gas separation adsorbents. Although POPs have amorphous morphology in general, with the help of organic chemistry toolbox, ultrahigh surface area materials can be synthesized. In particular, nitrogen-rich POPs have been studied intensively due to their enhanced framework-CO₂ interactions. Postsynthetic modification (PSM) of POPs has been instrumental for incorporating different functional groups into the pores of POPs which would increase the CO₂ capture properties. We have shown that functionalizing the surface of POPs with nitro and amine groups …

Measurement Of Rare Earth And Uranium Elements Using Laser-Induced Breakdown Spectroscopy (Libs) In An Aerosol System For Nuclear Safeguards Applications, Ammon N. Williams

Theses and Dissertations

The primary objective of this research is to develop an applied technology and provide an assessment for remotely measuring and analyzing the real time or near real time concentrations of used nuclear fuel (UNF) elements in electrorefiners (ER). Here, Laser-Induced Breakdown Spectroscopy (LIBS) in UNF pyroprocessing facilities was investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantages of applying the …

Laser Vaporization Controlled Condensation And Laser Irradiation In Solution For The Synthesis Of Supported Nanoparticle Catalysts, Vitaly Kisurin Mr.

Theses and Dissertations

Solid catalyst supports of SiOx-RGO (Reduced Graphene Oxide) and UiO-67 (Universitet i Oslo) have been successfully synthesized and were loaded with palladium nanoparticles to test for a series of heterogeneous reactions. The SiOx/RGO catalysts were synthesized through laser ablation of silicon and graphite oxide micron powder and UiO-67 metal-organic framework (MOF) was synthesized through mixing of precursors with DMF/HCl solution and washing the resultant powder from impurities. The SiOx/RGO supports were later impregnated with palladium precursors which were then subject to Microwave Irradiation (MWI). The UiO-67 framework was impregnated with palladium precursors and was irradiated with pulsed Nd:YAG 532 nm …

Characterization Of Cytidylyltransferase Enzyme Activity Through High Performance Liquid Chromatography, James Brault

Theses and Dissertations

The cytidylyltransferases are a family of enzymes that utilize cytidine 5â?? triphosphate (CTP) to synthesize molecules that are precursors to membrane phospholipids. There are four well known enzymes: CTP: phosphoethanolamine cytidylyltransferase (ECT), CTP: glycerol-3-phosphate cytidylyltransferase (GCT), 2-C-methyl-D-erythritol-4-phosphate cytidylyltransferase synthetase (CMS), and CTP: phosphocholine cytidylyltransferase (CCT). Previously, a radioisotope tagging method was employed to study cytidylyltransferase catalysis. Using CCT as a model, a method utilizing high performance liquid chromatography (HPLC) was developed to replace the radioisotope scintillation technique. The development of this new HPLC method is cheaper, more efficient, and more accurate than the previously established method.

The targets of separation …

Spectroscopy And Chemometrics For Cultural Heritage And Forensics: Conservation Of Magnetic Tape By Identifying Degraded Polymer Signatures; And Characterizing The Chemiluminescent Reaction Of Luminol With Blood, Brianna Marie Cassidy

Theses and Dissertations

The first half of this manuscript focuses on the identification of degraded magnetic tape using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and multivariate statistics. For several decades before the digital era, magnetic tape was the dominant audio and visual recording medium. A majority of magnetic tapes contain polyester urethane (PEU) binders, which are known to degrade via hydrolysis, making the retrieval of recorded data difficult and at times impossible. Degraded tapes are currently identified through visual inspection followed by playback on vintage equipment. However, if degraded tapes are played, they are likely to stick and shed onto player …

Defining The Effects Of Gdf-2 On TgfB Signaling In Tumorigenic Epithelial Cells, Tirthankar Bandyopadhyay

Theses and Dissertations

Cancer cells can be viewed as such cells, which have disrupted/aberrant signaling pathways for maintaining cellular homoeostasis. Identifying such altered signaling mechanisms can help us target these pathways in a better way. GDF-2 (Growth and differentiation factor – 2) or BMP9 (Bone morphogenetic protein – 9), a multifunctional cytokine, is a member of the Bone Morphogenetic Protein subfamily, under TGFβ superfamily, with roles distinct from BMP2/4/7. While GDF-2 is known to be one of the most potent ectopic inducers of bone and cartilage formation, it rose to significance with the identification of its receptor ALK1 in endothelial cells. TGFβ’s role …

Hydroxy Polybenzimidazoles For High Temperature Fuel Cells And The Solution Polymerization Of Polybenzimidazole, Kayley Fishel

Theses and Dissertations

In this dissertation, two different hompolymers of polybenzimidazole (PBI) containing hydroxyl functional units were synthesized via the PPA Process to produce gel membranes. These polymers and their phosphoric acid doped membranes were characterized to further explore structure-property relationships in functionalized PBI's. Fuel cell performance of the doped membranes was evaluated and compared to previously reported PBI membrane chemistries. Copolymers of p-OH PBI and para-PBI were prepared at five different copolymer compositions to examine the effects of hydroxy content on membrane properties and compared to the respective homopolymers. The reactivity of the hydroxy groups and the formation of phosphate bridges were …

Optical Spectroscopy And Chemometrics For Discrimination Of Dyed Textile Fibers And Magnetic Audio Tapes, Nathan C. Fuenffinger

Theses and Dissertations

This dissertation focuses on the application of both novel and standard chemometric approaches toward societal problems of interest in the areas of forensic science and cultural heritage preservation. Microspectrophotometry (MSP), a technique enabling measurements of absorption of electromagnetic radiation by microscopic materials in the ultraviolet-visible (UV-Vis) region, is widely used by forensic examiners for comparisons of metameric textile fibers. These comparisons are often hindered, however, by the raw or normalized spectra showing little detail or having few points of comparison. Derivative preprocessing can enhance structure in some instances. We have demonstrated through the use of multivariate statistics that derivatives are …

Optimization Of Shell Growth And Influence Of Surface Ligands For Colloidal Cdse/Cds Core/Shell Quantum Dots, Rui Tan

Theses and Dissertations

Progress in the colloidal synthesis of semiconductor quantum dots (QDs) has triggered a burst of research toward applications in QD based light emitting diodes, biological imaging as fluorescent tags, and advanced solar cell designs. In order to adjust and optimize the photo physical properties of QDs, QD heterostructures have been introduced and widely explored. This dissertation is focused on studies of growth of semiconductor colloidal CdSe/CdS core/shell quantum dots and the influences of neutral surface ligands to their photo-physical properties. Chapter 1 provides an introduction of the concept of semiconductor colloidal nanoparticles, core/shell heterostructures and the synthesis methods as well …

Approaching Aromatic Interactions With Small Molecule Model Systems: Assessing N-Heteroarene In ∏ -Stacking And Ch-∏ Interactions, Crystal Engineering Of Atropisomeric Rotors, And Developing Responsive Organic Charge-Transfer Complex, Ping Li

Theses and Dissertations

Non-covalent interactions involving aromatic species are important in many areas in chemistry, biochemistry, and materials sciences. During the past two decades, small molecule model systems have emerged as a powerful tool to advance our knowledge of the stability trends for aromatic interactions in the condensed phase. Among these, the Cshape N-arylimide molecular balances developed by our laboratory have proven to be one most successful and versatile model systems that can be readily adapted to investigate various types of aromatic interactions. These molecular balances are particularly apt at isolating and accurately measuring the targeted weak aromatic interaction energies for different geometries. …

Optimized Spectral Processing Of Infrared Diffuse Reflection Spectra For The Detection Of Blood On Fabric, Stephanie Ann Dejong

Theses and Dissertations

The detection of bodily fluids such as blood on interfering backgrounds is important to the forensic community. Luminol, which participates in a chemiluminescent reaction with the heme groups of blood, is one of the most commonly used presumptive tests. Luminol has a few drawbacks, including the requirement of use in a dark environment and potential to degrade the amount of recoverable DNA in blood stains. A potential complementary method is infrared (IR) spectroscopy. These two methods are compared in this work. Infrared diffuse reflection (DR) spectroscopy works well to measure the IR spectrum of samples that are highly absorbing or …

Two-Dimensional Transient Spectroscopy Measuring Heterogeneity In Electronic And Rotational Dynamics, Haorui Wu

Theses and Dissertations

Multiple population-period transient spectroscopy (MUPPETS) is a picosecond, time resolved experiment that uses a sequence of six laser pulses. It was previously known that MUPPETS could measure heterogeneity in electronic-state decay. This dissertation presents two projects that extend MUPPETS to new processes. One process is the extension from 2-level system into 3-level system, another new process extends the kinetics from electronic decay to rotational decay. In addition, a third, ongoing project on rotational dynamics in ionic liquids will also be discussed briefly. The first project consisted of two main parts. The first part focused on the biexciton decay in semiconductor …

Applications Of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy For Forensic Analysis, Zhenyu Lu

Theses and Dissertations

Blood stains, which are among the traces encountered most frequently at crime scenes, are important for potential extraction and amplification of DNA for suspect identification, as well for spatter pattern analysis to reveal a sequence of events. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used in detection of blood stains and age estimation because of signature absorbances in the mid-infrared region at 3300 cm-1 (Amide A), 2800-3000 cm-1 (Amide B), ~1650 cm-1 (Amide I), ~1540 cm-1 (Amide II) ,and 1200-1350 cm-1 (Amide III). Position and intensity shifts for amide peaks were observed due to aging changes occurring as …

Sustainable Polymeric Materials Derived From Novel Soybean Based Monomers And Polymers: From Synthesis To Applications, Nathan Trenor

Theses and Dissertations

In this thesis, monomers and polymers derived from high oleic soybean oil are investigated. The properties of these monomers and polymeric materials are characterized and discussed. Chapter 1 describes an overall background of bio-based resources, monomers, polymers, and their potential impact on society. Polymerization techniques are introduced, and the overall objective of my research is described. Chapter 2 outlines the large scale preparation of a soybean based monomer and the use of this monomer in thermoset elastomers. The synthetic procedures and characterizations of the monomers and polymers are discussed. A model study using oleic acid is described and proved to …

Novel Block Copolymer Architectures For Lithography-Relevant Self-Assembly, Jeffery Hakim Hayat

Theses and Dissertations

This dissertation is focused on the synthesis, characterization, self-assembly, and materials processing of various functionalized block copolymer systems. A variety of monomers were prepared and polymerized through various polymerization techniques including atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, and ring-opening metathesis polymerization. Self-assembly of the functionalized block copolymers led to well-defined nanostructures in bulk and thin films. These materials have the capability to be utilized in various applications including ordered catalysts and templates for nanolithography. In Chapter 1, the overall background of diblock and triblock copolymers and their preparation methods is in this dissertation. Major research objectives of …