Physical Sciences and Mathematics Commons^™

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 …

Investigation Of 89zr-Siderophores As Molecular Imaging Agents For Positron Emission Tomography Imaging Of Bacterial Infections, Nora C. M. Goscinski

Arts & Sciences Electronic Theses and Dissertations

Siderophores are small molecules synthesized by bacteria to harvest Fe³⁺ from their environment. In infection scenarios, their production can increase infection virulence by increasing the ability of bacteria to obtain Fe³⁺ and therefore grow more rapidly. The selective uptake of siderophores in vivo in multi-bacteria environments indicates that this class of molecules has a potential use as selective imaging agents. In this work, DFO-NCS and a library of trihydroxamate siderophores were evaluated as vehicles to deliver ⁸⁹Zr selectively to bacteria for Positron Emission Tomography (PET) imaging of bacterial infections.

Productive work with radiometals involves thorough knowledge of …

Vibrational Imaging At The Nanoscale: Surpassing The Diffraction Limit Using Tip-Enhanced Raman Spectroscopy, Farshid Pashaee

Electronic Thesis and Dissertation Repository

A deep understanding of the chemical composition of surfaces, interfaces or nanoscale structure with a high spatial resolution is an important goal in nanoscience and nanotechnology. Structural information can be collected using a variety of high spatial resolution techniques such as atomic force microscopy (AFM), scanning tunneling microscopy (STM), scanning electron microscopy (SEM), or transmission electron microscopy (TEM). Nevertheless, these methods do not offer molecular information such as vibrational spectroscopy techniques that allow one to collect molecular or lattice vibrations yielding to a precise picture of the molecular interactions in bulk materials as well as in surfaces and interfaces. Unfortunately …

Rapid Dissolution For Destructive Assay Of Nuclear Melt Glass, Jonathan Allen Gill

Masters Theses

This study evaluates four methods for dissolving complex glassy debris resulting from nuclear detonations. The samples of interest simulate the glassy debris generated from a nuclear detonation’s fireball coming in contact with solid masses. Each method attempts to achieve dissolution through different approaches involving either acid digestion, alkaline digestion, or molten salt fusion. Two of the four methods were modified to retain all elements of the debris or surrogate debris. This retention is critical to the proportional relationships used in identifying fuel types and designs of nuclear weapons. Analysis is conducted with an inductively coupled time of flight mass spectrometer …

The Unique Electrochemical Reactivity Of Small Metal Nanoparticles., Rafael A. Masitas

Electronic Theses and Dissertations

This dissertation describes the factors controlling metal nanoparticle (NP) oxidation, using Au oxidation in Br- and Ag oxidation in acid as model systems. We found that the oxidation potential depends on size, surface charge, and electrode material. Size has a dramatic effect, shifting about 200 mV from > 200 nm diameter down to 4 nm diameter. The shift is more dramatic below 4 nm. 2.3 nm average diameter Au NPs oxidized in the 300-500 mV range and 1.5 nm average diameter Au NPs displayed several sharp peaks from 200 mV to as low as -200 mV. These smallest Au NPs show …

Electrochemical Formation Of One-Dimensional Metal Nanostructures Across Microgaps Electrodes For Resistive Switching And Optical Sensing Applications., Nidhi Shah

Electronic Theses and Dissertations

This dissertation focuses on the electrochemical formation of one-dimensional (1D) Ag nanostructures (in particular nanowires and nanochains) directly on electrode surfaces or gap of two electrodes. Ag nanowires (NWs) and nanorods (NRs) grow directly on glass/indium tin oxide (ITO) surfaces from electrode-attached Au nanoparticle seeds in the presence of cetyltrimethylammonium bromide (CTAB) at appropriate potentials with a 5-15 % yield and the average length ranging from 100 nm to 3 µm for growth times of 30 to 120 min. This method failed when trying to grow Ag NRs/NWs across 5 µm Au electrode gaps. Interestingly, applying voltage in air leads …

Studying Nanoparticle/Cell And Nanoparticle/Biosurface Interaction With Mass Spectrometry, Singyuk Hou

Masters Theses

Nanoparticles (NPs) have been used widely in various fields ranging from biomedical applications to life science due to their highly tunable properties. It is essential to understanding how NPs interact with biological systems of interest, therefore, analytical platforms to efficiently track NPs from cell to animal level are essential. In this thesis, laser desorption ionization mass spectrometry (LDI-MS) and inductively-coupled plasma mass spectrometry (ICP-MS) has been developed and applied to quantify NP/cell and NP/biological surface interactions. These two methods provide fast, label-free and quantitative analysis. New capability of LDI-MS to differentiate cell surface-bound and internalized NPs were established and ICP-MS …

Utilizing In Silico And/Or Native Esi Approaches To Provide New Insights On Haptoglobin/Globin And Haptoglobin/Receptor Interactions, Ololade Fatunmbi

Doctoral Dissertations

Haptoglobin (Hp), an acute phase protein, binds free hemoglobin (Hb) dimers in one of the strongest non-covalent interactions known in biology. This interaction protects Hb from causing potentially severe oxidative damage and limiting nitric oxide bioavailability. Once Hb/Hp complexes are formed, they proceed to bind CD163, a cell surface receptor on macrophages leading to complex internalization and catabolism. Myoglobin, (Mb) a monomeric protein, that is normally found in the muscle but can be released into the blood in high concentrations during myocardial injury, is homologous to Hb and shares many conserved Hb/Hp interface residues. Both monomeric Hb and Mb species …

Inkjet Printing For Biosensing And Security Applications, Brian Creran

Doctoral Dissertations

The adaptation of inkjet printing technology has recently been used to create controlled high throughput micro- and nano-scaled structures. Coupling this technique with gold nanoparticles in our research has produced new platforms for biosensors, chemical patterning, and anti-counterfeiting applications. In this presentation, we will highlight promising fabrication strategies including the development of test strips for the determination of bacteria in drinking water as well as the use of patterned nanoparticles for security applications.

Protein Charge Anisotropy Mediated Self-Association And Phase Separation, Daniel P. Seeman

Doctoral Dissertations

Protein charge anisotropy results from the asymmetric distribution of charged residues on the exterior of a particular protein. Interactions between proteins and other macromolecules can be described in terms of attractive electrostatics; since electrostatic free energies, at optimal I, are on the order of kT, it is unlikely that such associations would result in desolvation, thus it is reasonable to consider such intermolecular attractions as being mediated by hydrated protein surfaces. Such interactions can be broken down in terms of a single protein interacting with a range of “binding partners”, including (1) protein-protein interactions, (2) protein-polymer interactions, and …

Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby

Chemistry & Biochemistry Theses & Dissertations

Organic aerosols (OA) are universally regarded as an important component of the atmosphere based on quantitative significance as well as the far-reaching impact they have on global climate forcing and human health. Despite the acknowledged importance, OA amounts and impacts remain the largest uncertainties regarding radiative forcing estimates. Incomplete chemical characterization of aerosol organic matter (OM) and a lack of concrete source apportionment is a major source of this uncertainty. The primary focus of this study is to provide much needed molecular details regarding ambient OA from key emission sources, and establish links between molecular and optical properties.

Complete chemical …

Mass Spectrometric Analyses Of Surface Proteins From Candida Albicans After Treatment With Histatin 5, Shirley Fan

Electronic Thesis and Dissertation Repository

Current drug therapies have lost their effectiveness in controlling the fungal species known as C. albicans; therefore, the need for newer drugs becomes crucial. Histatin 5 (Hst 5), a naturally occurring peptide found in the oral cavity, has demonstrated strong effects on controlling candidiasis. Here, we have proposed that the adhesion of cells through surface proteins is an important process. To allow the analysis of surface proteins, the concept of on-whole cell tryptic digestions were developed. This on-target approach allows for isolation of the peptides of interest, while greatly reducing digestion times.

To study the effects of Histatin 5 …

Optimization Of Cu2znsns4 Nanocrystal Composition And Thin Film Fabrication For Photovoltaic Applications, Saghar Khoshmashrab

Electronic Thesis and Dissertation Repository

In this work Cu2ZnSnS4 (CZTS) nanocrystals (NCs) were prepared via a solvothermal, one-pot method. Given that the composition affects the electronic properties of this p-type semiconductor, comparative compositional analysis was done from various designed and synthesized analogues. EXAFS studies indicated that the stoichiometries with lower Cu-contents (Cu Sn+Zn

The effects of Cu were further studied, using Cu-poor and Cu-stoichiometric NCs.This time the precursor content of Zn was also increased to yield samples with Zn rich compositions. NCs in which the Cu concentration was below stoichiometric (Cu1.8Zn1.1Sn1.0S4.8) were more crystalline and yielded a higher photoresponse (~53 μA/cm2).

The compositionally optimized CZTS …

Reactions Between Zinc Metallothionein And Carbonic Anhydrase, Tyler B. J. Pinter

Electronic Thesis and Dissertation Repository

More than 25% of proteins require metal ion cofactors for structure or function. The interactions between metalloproteins have largely been overlooked, though these interactions ultimately govern metal localization and control metal ion homeostasis. Mammalian metallothionein (MT) is a small, cysteine-rich metalloprotein that binds numerous metal ions per protein strand. Up to seven divalent metals, such as zinc or cadmium, are wrapped into a clustered two-domain structure. This unusually high metal content places MT as an attractive candidate for studying interactions with other metal-binding proteins. This present study investigates the metal transfer reactions between MTs and other metalloproteins, using carbonic anhydrase …

Design And Fabrication Of Integrated Plasmonic Platforms For Ultra-Sensitive Molecular And Biomolecular Detections, Mohammadali Tabatabaei

Electronic Thesis and Dissertation Repository

One of the major challenges in analytical and biological sciences is to develop a device to obtain unambiguous chemical and structural properties of a material or a probe biomolecule with high reproducibility and ultra-high sensitivity. Moreover, in addition to such a high sensitivity, other cases such as minimum intrusiveness, small amounts of analyte, and short acquisition time and high reproducibility are key parameters that can be valued in any analytical measurements. Among the promising methods to achieve such endeavor, plasmon-mediated surface-enhanced spectroscopic techniques, such as surface-enhanced Raman spectroscopy (SERS), are considered as suitable options. Such techniques take advantage of the …

Method Development For Vitamin C Quantification In Two Complex Matrices, Hannah D. Hutt

Electronic Theses and Dissertations

The following liquid chromatographic (LC) method developments and applied research studies were done using two complex food matrices, potatoes and elderberries, which are common to the state of Maine. Potatoes are Maine’s largest agricultural crop, a staple food in most U.S. households, and are, from an analytical standpoint, considered a complex matrix due to the high starch content that can be difficult to remove without degrading or removing nutrients in the process. Elderberries are an emerging crop in the U.S. because of their antioxidant and anti-viral properties and are found growing wild, throughout Maine. Elderberries are also considered a complex …

Detection Of Iron (Iii) Using Magnetic Nanoparticles, Kaiya Hansen

Electronic Theses and Dissertations

The goal of this work was to develop an iron (III) sensor which can be mounted on buoys and gliders and automatically measure iron (III) in the ocean. The method investigated in this thesis was based on anchoring the iron (III) chelator desferrioxamine B (DFB) to magnetic particles. DFB selectively binds iron (III), resulting in a complex which produces a broad absorbance band at 430 nm. This band can be measured via UV-Vis spectroscopy (UV-Vis). However, measuring oceanic iron (III) directly in solution is difficult because the concentrations can be very low, sometimes less than 1 nM. This problem could …

X-Ray Absorption Fine Structure Studies Of Calcium Silicate Hydrate Biomaterials In Drug Delivery, Xiaoxuan Guo

Electronic Thesis and Dissertation Repository

Calcium silicate hydrate (CSH), a new type of bioceramics, has gained significant attention in hard tissue restoration because of their impressive role in the stimulation of osteoblast proliferation and differentiation in vitro. The further development of mesoporous bioceramics opens up new opportunities for drug delivery in hard tissue therapies. In this thesis, interaction mechanisms of drug molecules with CSH of different morphologies and CSH/polymer composites, imaging of drug distributions in CSH carriers in nanoscale, and the biomineralization mechanisms of CSH in vitro during drug release are extensively investigated using X-ray absorption near edge structure (XANES) and scanning transmission X-ray …

Transferrin-Based Therapeutics And Analytical Methods To Characterize Them, Son N. Nguyen

Doctoral Dissertations

Modern development of medicine requires detailed characterization by state-of-the art analytical techniques that can be used to analyze covalent structure, conformations and protein-receptor interaction to quantitatively measure biodistribution of protein therapeutics. Mass spectrometry has already become an indispensable tool facilitating all stages of protein drug development. Particularly, this work has demonstrated the tremendous potential of electrospray ionization (ESI) mass spectrometry (MS) in this arena by providing invaluable information beyond mass measurement that can be used to optimize protein drug conjugate structures during early stages of development, and to further catalyze drug design efforts. Additionally, a new sensitive and selective method …

Study Of The Secondary Metabolites Of Black Aspergilli From Canadian Vineyards, Tianyu Qi

Electronic Thesis and Dissertation Repository

Ochratoxin A (OTA) and fumonisin are mycotoxins produced by black Aspergilli that contaminate wine in many countries around the world. Both OTA and fumonisins are possible carcinogens to humans. There is limited data about the occurrence of OTA and fumonisins in Canadian vineyards. Therefore, a survey of the black Aspergilli from 2012-2014 has been conducted. In the mycotoxin study, high performance liquid chromatography-mass spectrometry was used to screen and quantify OTA and fumonisins from both black Aspergilli isolated on artificial media and grape samples. OTA was only detected from one fungal isolate and not on any grapes. Fumonisin B_{2 …}

Fluorinated Metallo Phthalocyanines For Chemical And Biological Catalysis, Hemantbhai H. Patel

Seton Hall University Dissertations and Theses (ETDs)

The rational design of robust oxidation catalysts based on organic molecules is hindered by the presence of labile C-H bonds. We have shown recently that replacing all C-H bonds by a combination of fluoro- and perfluoro-groups in a bioinspired Cytochrome P450 model based on a phthalocyanine, Pc, scaffold results in a stable yet reactive oxidation catalyst. The Pc cobalt complex catalyzes, for example, the aerobic oxidation of thiols to disulfides, a reaction of both biological significance and industrial importance.

The presence of robust C-F bonds, however, renders the catalyst unsuitable for attachment to solid-state supports, except via van der Waals …

Applications Of Green Chemistry In Asymmetric Transfer Hydrogenation And Chiral Separations, Ruoqiu Wu

Seton Hall University Dissertations and Theses (ETDs)

Green chemistry has been applied to all aspects of the life cycle of chemically related products, including design, usage, manufacturing, analysis, and disposal. In this thesis, I focus on the green chemistry applications in organic synthesis and analytical chemistry. More specifically, allylic and chiral alcohols are abundant in natural sources such as in essential oils, and widely utilized as starting materials. They are also major components in food, fragrance, biocides and the pharmaceutical compounds. In this thesis, I report the first Ru-catalysed asymmetric transfer hydrogenation (ATH) of prochiral allylic alcohols. This reaction provides chiral secondary alcohols in excellent enantioselectivities and …

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected …

Advances In High-Throughput Analysis: Automated Radiochemical Separations And Nanopillar Based Separations And Field Enhanced Spectroscopy, Jennifer Jeanne Charlton

Doctoral Dissertations

Often the need to analyze a large number of samples coincide with critical time consternates. At such times, the implementation of high-throughput technologies is paramount. In this work we explore some viable pathways for high-throughput analysis and develop advancements in novel forms of detection of materials that are vital in the environmental, biological as well as national security arenas. Through the use of new protocols with high sensitivity and specificity as well as simplified chemical processing and sample preparation we aim to allow for improved throughput, fieldable detection, and rapid data acquisition of extensive sample sets. The methods developed in …

Linkage Analysis And Compositional Studies Of Β-Glucan From Saccharomyces Cerevisiae And Compositional Studies Of Mannan From Candida Albicans, Clara Arthur

Electronic Theses and Dissertations

The efficacy of a novel carbohydrate extraction procedure was investigated with methylation analysis and alditol acetate method by Gas Chromatography-Mass Spectrometry. A published extraction procedure for β-glucans was compared to one developed in house. Both procedures gave a dominant glucose peak in the Gas chromatogram indicative of successful β-glucan isolation. Further linkage studies showed four linkage positions for β-glucans isolated with the published method; terminal, 1,3-linkage, 1,6-linkage and 1,3,6-linkage, while β-glucans isolated using the new method showed six linkage positions; terminal, 1,3-linkage, 1,6-linkage, 1,4-linkage, 1,2,3-linkage and 1,3,6-linkage. Diminishing β-glucan linkage peaks in the chromatogram for the published method indicated structure …

Real-Time Spectroscopic Analysis Of Microalgal Adaptation To Changing Environmental Conditions, Robert Ked Byrd

Masters Theses

Increases in anthropogenic pollution are causing many environmental problems; understanding their impact on the environment has become an important issue. Industrialization and the burning of fossil fuels have caused increased levels of carbon dioxide to enter the atmosphere, which is contributing to global warming and ocean acidification. Agricultural runoff has caused levels of inorganic nitrogen and phosphorus to rise, where they have been noted to cause harmful algal blooms. Marine ecosystems have been particularly affected as both of these forms of pollution accumulate in bodies of water. Microalgae are important organisms in these ecosystems because they sequester these pollutants and …

Complementary Mass Spectrometry Methods For Characterizing Protein Folding, Structure, And Dynamics, Siavash Vahidi

Electronic Thesis and Dissertation Repository

Proteins are involved in virtually every biochemical process. A comprehensive characterization of factors that govern protein function is essential for understanding the biomedical aspects of human health. This dissertation aims to develop complementary mass spectrometry-based methods and apply them to solve problems pertaining to the area of protein structure, folding and dynamics.

‎Chapter 1 uses fast photochemical oxidation of proteins (FPOP) to characterize partially disordered conformers populated under semi-denaturing conditions. In FPOP, ·OH generated by laser photolysis of H₂O₂ introduces oxidative modifications at solvent accessible side chains. By contrast, buried sites are protected from radical attack. Using …

Hydrogen Exchange Mass Spectrometry For Studying Protein-Ligand Interactions, Modupeola A. Sowole

Electronic Thesis and Dissertation Repository

Hydrogen deuterium exchange (HDX) coupled with mass spectrometry is widely used for probing protein structure and dynamics. Protein-ligand interactions usually induce a reduction in the measured HDX rates an effect that may be ascribed to stabilization of the protein structure. This work aims to improve the general understanding of the changes in HDX patterns associated with ligand binding.

We initially applied HDX for studying differences between oxy-hemoglobin (Oxy-Hb) and aquomet-hemoglobin (Chapter 2). The results show that the α and β subunits respond differently to the oxy to aquomet transition with the heme binding pocket being destabilized in both cases. The …

Determining % Proliss 100 In Keratin Mousse Using Iodine Solution Method, Quiana Moore

All Capstone Projects

The objective of this experiment is to quantitatively determine the amount of active raw material Proliss 100 manufactured and supplied by a formulation company. The goal is to reproduce the percent of Proliss in Keratin Mousse production sample provided to consumers and provide measurements to be used to assess the accuracy of production with comparison to provided percent formulation for each batch. An iodine solution titration method was performed for this experiment due to the reduction-oxidation reactivity of the Proliss 100. This experiment is still undergoing further testing due to the confidentiality agreement between the manufacturer and formulator.

In Vitro Microdialysis Sampling Collection Of Volatile Organic Compounds (Voc's), Dodecafluoropentane (Ddfp) And Isoflurane, Valerie Shannon Mckinney

Graduate Theses and Dissertations

Death by stroke occurs every four minutes to human beings. Strokes cause necrosis within the tissue of the brain due to deprivation of oxygen. Perfluorocarbons have the ability to transport oxygen to tissue and in return decrease cell death. Dodecafluoropentane (DDFP) is a volatile fluorocarbon and collection in vivo can be a challenge since this compound evaporates at room temperature. There is currently not an efficient collection method in vivo for compounds that are volatile. Without a method to collect DDFP it is impossible to be approved for clinical use since exact concentrations of the drug within the body will …