Chemistry Commons^™

Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry: A High-Throughput Platform In Metabolomics For Assessment Of Lifestyle Interventions In Human Health, Naomi L. Kuehnbaum

Open Access Dissertations and Theses

Research in this thesis has focused on development and application of novel methodologies that enhance sample throughput and data fidelity when performing untargeted metabolome profiling by multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS). Metabolomics is a valuable tool in functional genomics research to investigate underlying molecular mechanisms associated with human health since metabolites are “real-world” end-products of gene expression. CE-MS is well-suited for metabolomics because it is a high efficiency microseparation technique that can be used to resolve complex mixtures of polar metabolites in human biofluids without complicated sample workup. In this thesis, a novel CE-MS assay for estrogens and their intact ...

The Influence Of Microstructure On The Corrosion Of Magnesium Alloys, Robert M. Asmussen

University of Western Ontario - Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations into the influence of microstructure on the corrosion of Mg alloys. Mg alloys are prime candidates for the light-weighting of automobiles however any extensive applications are limited by their high corrosion rates. The corrosion resistance is further hindered by the susceptibility of Mg alloys to microgalvanic coupling occurring between the Mg matrix and the secondary microstructures in the alloys. This process and the individual contributions to it must be understood to improve Mg alloy design for automotive applications, develop methods for extending the lifetime of Mg alloys and developing models to successfully predict ...

Application Of Nuclear Magnetic Resonance Based Metabolomics To Study The Central Metabolism Of Staphylococci, Bo Zhang

Student Research Projects, Dissertations, and Theses - Chemistry Department

Metabolomics studies the collection of small molecules (metabolites) involved in enzymatically catalyzed reactions, cell signaling and cellular structure. Perturbations in metabolite concentrations have been used to reflect the activity of corresponding enzymes or proteins. Nuclear magnetic resonance (NMR) spectroscopy is a well-known approach for the structure determination of biological macromolecules. Alternatively, NMR has recently been established as a valuable tool of metabolomics, in which NMR spectral signals correlate small molecules with cellular activities. This has been accomplished through the chemometric analysis of high-throughput one dimensional ¹H spectra (metabolic fingerprinting) and quantitative metabolite identification based on two dimensional ¹H ...

Generation Of Chimeric Antibody Light Chain Plasmid, Lily Arendt

DePaul Discoveries

In order to determine the distance between the antigen-binding site and the fragment crystallizable (Fc) region of an antibody using single-molecule Förster Resonance Energy Transfer, dyes must be attached to these locations. To accomplish this, the variable regions of the light and heavy chains of an antibody can be modified and a dye-reactive amino acid introduced into the Fc region. Initial attempts to alter the variable light chain (V_L) gene included trying to ligate a 350bp variable gene into an 11,000bp plasmid. When these attempts were unsuccessful, the variable light chain gene was ligated into a commercially available ...

Interactions Of Eukaryotic Translation Initiation Factors And 3' Untranslated Region Of Barley Yellow Dwarf Virus Mrna During Protein Synthesis: A Study Of Equilibrium Binding, Kinetics And Thermodynamics, Bidisha Banerjee

Dissertations and Theses, 2014-Present

Eukaryotic initiation factor (eIF) 4F binding to mRNA is the first committed step in cap-dependent protein synthesis. Barley Yellow Dwarf Virus (BYDV) employs a cap-independent mechanism of translation initiation which is mediated by a structural element BTE (BYDV translation element) located in the 3’ UTR of its mRNA. eIF4F bound the BTE and a translational inactive mutant with high affinity; thus questioning the role of eIF4F in translation of BYDV. To examine the effects of eIF4F in BYDV translation initiation, BTE mutants with widely different in vitro translation efficiencies ranging from 5-164% compared to WT were studied. Using fluorescence anisotropy ...

The Application Of Dispersion Staining And Infrared Microspectroscopy To Analyze Physical Evidence In Developing Countries, Thiti Mahacharoen

Dissertations and Theses, 2014-Present

In developing countries like Thailand and in remote forensic laboratories around the world, scientific investigations of crimes are limited by the shortage of trained personnel and financial resources. The premise of this research is that polarized light microscope and dispersion staining methods will be developed which allow investigators with limited training to analyze physical evidence at a minimal cost. This research identifies specific liquids for the analysis of trace evidence using the dispersion staining technique. The development of dispersion staining technique and identification of specific liquid will extend the application of forensic science to remote laboratories and in the field ...

Studies On The Synthesis Of Orthogonally Protected Azalanthionines, And Of Routes Towards B-Methyl Azalanthionines, By Ring-Opening Of N-Activated Aziridine-2-Crboxylates, Keith O'Brien, Keith O Proinsias, Fintan Kelleher

Articles

Orthogonally protected azalanthionines were successfully synthesised by the ring-opening of N-activated aziridine-2-carboxylates with protected diaminopropanoic acids (DAPs). The required DAPs were also prepared by ring-opening of N-activated aziridine-2-carboxylates with para-methoxybenzylamine, but it was found that the choice of aziridine protecting groups dictated both the success of the reaction as well as the regioselectivity of the isolated products. Attempts to extend the methodology to the preparation of the more sterically demanding b-methyl azalanthionines have, so far, been unsuccessful.

Development And Implementation Of Dispersion Phase Diagrams (Dpds) For Four Different Hydrophobically Modified Ethoxylated Urethane (Heur) Based Acrylic Paint Systems, Tyler J. Bell

Master's Theses and Project Reports

Latex polymers serve as binders in a wide range of architectural paints and coatings. A latex is an aqueous colloidal dispersion of polymer particles that when dried above the polymer’s film formation temperature coalesces into a dry polymer film (Dragnevski, Routh, Murray, & Donald, 2010). The other main components of paint include associative thickeners, surfactants, pigments and fillers with the thickener being the primary area of focus for this study.

The relatively simple system of latex, associative thickener and surfactant has been studied extensively. These studies have shown the mechanism of thickening for the associative thickener, and surfactant effects on both latex and thickener; however, there are few studies conducted for a fully-formulated system. The introduction of pigments, fillers, coalescing aids, functional amines, and other additives greatly increases the difficulty of research in this area. The addition of many additives ultimately affects the stability and physical properties of the end-product. Phase separation of the paints, also called syneresis, is a major ...

Organic Peroxides (And Ozone): Safety-Oriented Overview, Patrick Dussault

Organic Peroxides: Safety Issues

The following is a brief introduction to organic peroxide safety from the viewpoint of synthetic chemistry. Topics include classes of peroxides and hydroperoxides, reactivity of organic peroxides, hazard identification (including the concept of active oxygen content), hazard minimization, reaction monitoring using peroxide-sensitive strips and TLC dips, and references to further reading on peroxide safety.

Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego F. Amado Torres

Diego Amado Torres

Proteins have the capacity to bind specific sets of compounds known as ligands, these are small molecules with a recurrent theme in their molecular design that is a characteristic exploited here to (i) identify particular affinities of small molecules for proteins with the aim of using them as ligands, inhibitors, or targeting moieties in more complex systems by means of a methodology that screens small molecules based on protein affinity; (ii) decorate a self-assembling supramolecular system at different positions, making it responsive to a complementary protein with the aim of exploring differences in disassembly and sensitivity of the release of ...

Kinetics Of Solid Phase Crystallization Of A-Ge Thin Films, John D. Graham

Macalester Journal of Physics and Astronomy

A method was developed to investigate the solid-phase crystallization (SPC) reaction undergone by germanium thin films. Amorphous films were grown by the radio-frequency (RF) magnetron sputtering and then annealed for a maximum of 6 hours at two temperatures: 446°C and 460°C. Crystallinity was measured by resistivity measurements, as well as crystal peak height and area taken from X-ray diffractometer (XRD) data. Initial data shows qualitative agreement with a nucleation-growth model for the observed kinetic process. However, observed peak narrowing phenomena suggests a comprehensive model of XRD measurements of polycrystalline thin films is needed for a rigorous interpretation of ...

Force Constants Of Coordinated Co And Β-Amino Substituted Isocyanides Using Infrared Spectroscopy, Laura Avena

Macalester Journal of Physics and Astronomy

Metal carbonyls and isocyanides have characteristic peaks in infrared spectra. While the energies are useful in a qualitative determination of relative bond strengths, a more quantitative approach is needed to cross-compare similar complexes. Using a harmonic oscillator approximation, it is possible to determine the effective force constants of carbon-oxygen and carbon-nitrogen bonds. This allowed me to show that negatively charged bis(diphenylphosphinomethyl)diphenylborate used in our laboratory is a better donor than its neutral analogue 1,2-bis(diphenylphosphino)ethane.

Metal-Organic Frameworks Based On Pyridyl-Tetrazole Ligands Containing Ester Or Carboxylate Pendant Arms, Ursula Sheridan, John Gallagher, Morten Bjerrum, Adrienne Fleming, Fintan Kelleher, John Mcginley

Articles

The coordination of pyridyl-tetrazole derivatives containing ester substituents, at either the N-1 or N-2 position of the tetrazole ring, with copper(II) chloride results in the formation of either 1:1 or 1:2 copper to ligand complexes, depending on the ligand. However, when the ester functionality is changed to a carboxylate group, the resulting complexation reactions yield metal-organic frameworks. The resulting structures vary dramatically in pore size, depending on both reaction solvents and position of carboxylate group on the tetrazole ring. Despite the presence of sodium cations in the reaction mixtures, no sodium incorporation was ever observed in any ...

Roesner To Receive National Teaching Award, Kim Hill

News and Events

No abstract provided.

Branching Into Rnai: Synthesis, Characterization And Biology Of Branch And Hyperbranch Sirnas, Anthony Muriithi Maina

Seton Hall University Dissertations and Theses (ETDs)

The cancer epidemic continues to afflict millions of humans world-wide each year and despite a renewed hope with the development of new and improved forms of therapy, a cure for cancer remains an elusive goal. This is partly related to the rise of resilient forms of tumors that have evolved with resistance towards conventional chemotherapy and radiation treatments. Moreover, these non-specific therapeutic regimens are highly toxic, leading to severe immunosuppressive effects which poisons the body and compromises the road towards remission. In an effort to mitigate these limitations, cancer-targeting approaches are currently experiencing a renaissance in the translation of new ...

Mercury Bioaccumulation In Bat Populations In Mammoth Cave National Park: Modern, Historical, And Ancient Samples, Stephanie Hagan

Honors College Capstone Experience/Thesis Projects

The first human to enter Mammoth Cave passed under its arch about 4,000 years ago, but bats have been calling it home long before humans discovered it. Due to environmental exposure of mercury, these bats potentially show substantial mercury bioaccumulation. Bats now come into contact with mercury through atmospheric deposition from industrial sources. It is expected that the modern bats residing in Mammoth Cave should have measurable levels of mercury in their system which has been determined by guano analysis. Over fifty current samples of bat guano have been analyzed and exhibit mercury levels at the part per billion ...

Mechanochemistry: Pyrene Derivatives In The Detection Of Select Metals, Hillary Asberry

Honors College Capstone Experience/Thesis Projects

Metals are found naturally in the environment and expelled through industrial waste. When absorbed through the skin, inhaled, or ingested, many metals have been proven to cause numerous health problems. Mechanochemistry using a mortar and pestle grinding shows promise in capture and detection of toxic metals. This method allows for an on-site, cost effective, simple, solvent free, and environmentally friendly metal coordination. Pyrene derivatives with diethylenetriamine and bis(3-aminopropyl)amine linkers have shown to be successful fluorescent receptors serving as a Lewis bases in the reactions. After coordination, color changes are observed in visible light and UV light. Metal salts ...

The Analysis Of Experimental Error In Parity Violation Experiments With Polarized Neutrons, Jonathan Serpico

Honors College Capstone Experience/Thesis Projects

Measurements of parity symmetry violation in nuclear reactions with polarized neutrons can provide valuable information on hadronic weak interaction. We have conducted an analysis of experimental error in the measurement of the parity violating eect in the n3He experiment. several experimental parameters have been optimized to minimize statistical error using numerical simulations. An analysis of systematic error due to diferential cross-section dependence on energy as well as on false parity conserving asymmetries was also conducted. Our results suggest that the proposed parameters of the experiment will suficiently suppress all sources of error under consideration. Furthermore, these approaches may be effectively ...

Laser Intensity And Ionic Strength Dependence Of The Aqueous Nitrate And Carbonate Ion Raman Spectra, Samuel White

Honors College Capstone Experience/Thesis Projects

The geometry (and hence vibrational modes) of aqueous nitrate ion, NO₃^-, is known to depend on the solution composition—concentration, counter ions, etc. If a definite relationship between the vibrational spectrum and ionic strength of the solution could be established, it could be a useful monitor of solution composition over time. This would be valuable in studying the reaction rates and mechanisms of reactions involving nitrate in an aqueous environment, such as its photolysis in snow. Previous work in our lab observed a split peak at the symmetric-stretch mode of nitrate, though this mode does not usually show multiple ...

Herbal And Holistic Medicine In Latin America, William H. Lyle

Honors College Capstone Experience/Thesis Projects

A variety of herbal and holistic remedies were used in pre-Columbian cultures, especially in Aztec and Incan cultures. Many different herbs were used to provide medical attention to patients directly, while other herbs were used to supplement shaman^[1] medicine, which was particularly common in Inca culture. While there is little scientific basis for shamanism, as a viable healing option in modern culture, most herbal remedies had active chemical ingredients that could be or are used today to treat similar symptoms, and, in some cases, are being applied in different scenarios as well. The methods of usage, active chemicals, and ...