Physical Sciences and Mathematics Commons^™

Analysis Of The Zebrafish Olfactory System Using Immunohistochemistry And Enhanced Techniques Of Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Tara Lynn Maser

Dissertations

Desorption electrospray ionization (DESI-MS) is an ambient ionization technique where the sample is analyzed directly from a surface with very minimal sample preparation under ambient conditions and follows ESI-like ionization mechanisms. DESI-MS has proven powerful in analyzing or imaging lipids and other small molecules directly from biological samples and even allows for subsequent histological staining and analyses. However, DESI-MS is less widely used for protein analysis due to a lack of sensitivity and the complex diversity of proteins in biological samples.

A major goal of this research has been to obtain new neurobiological knowledge by combining histology and mass spectrometry …

Mechanisms And Applications Of Improved Protein Analysis By Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Roshan Javanshad

Dissertations

Electrospray ionization mass spectrometry (ESI-MS) is a soft ionization technique that allows detection of macromolecules, such as intact proteins, by the formation of multiply charged ions from solutions. Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient ionization technique that directly samples analyte from a surface during ESI-MS analysis. Although DESI-MS is highly accomplished at the analyses of metabolites, lipids, and other small molecules, it is far more limited when it comes to protein analysis. While most of the field in ambient ionization MS has moved towards primarily applications, our approach has been to explore the use of DESI-MS and …

Lxr Acts As A Differentiator In The Regulation Of Fas And G6pdh Gene Expression Under Insulin Resistant Conditions, Jaafar Hachem

Dissertations

Diabetes is a chronic disease that effects 10 percent of the world’s population and causes more than 1.5 million deaths a year and billions of dollars in associated health care cost. It can lead to very serious complications such as renal failure, liver cirrhosis, heart attack, and vision loss. The most common type of diabetes is type 2 diabetes. Type 2 diabetes arises when blood glucose levels remain chronically high due to insulin resistance. The reason for this elevation is due to the failure of insulin to allow tissues to uptake glucose causing problems in subsequent metabolic pathways. Over the …

Synthesis And Characterization Of Novel Organic Ligands With Their Complexes Of Platinum, Copper And Uranium, Mustafa Adnan Yasin Aldulaimi

Dissertations

Transition metal complexes of symmetrical and asymmetrical Schiff bases have played a significant role in the field of coordination, inorganic, and bioinorganic chemistry as models for biological, analytical, industrial, and pharmaceutical applications. Over recent years a great deal of interest has developed in new transition metal complexes of Schiff base ligand. The preparation of novel organic ligands is the most important step in the development of metal complexes that exhibit unique properties and novel reactivity. To highlight the presentation of this dissertation and to provide more detailed investigations, the dissertation was separated into six chapters according to the sequence of …

Embedded Gold Nanoparticles For Metal Enhanced Photoluminescence, Hasna Alali

Dissertations

Noble metal nanoparticles (MNPs) have attracted great attention in electronics, solar cells and catalysis. Their unique optical properties and biocompatibility makes them useful in biological applications like imaging, drug delivery, therapy and diagnostic. At the surface of MNPs the collective oscillation of free electrons resonates with a particular wavelength of incident light, generating the Localized Surface Plasmons Resonance (LSPR). LSPR results in absorption and scattering of incident light. Scattering results in reflecting photons and absorption leads to enhanced photoluminescence and quenching of fluorophores, if the fluorophore is in the vicinity of MNPs.

Most of the studies in this regard have …

Ultrafast Relaxation Dynamics In Graphene Oxide-Dye And Perovskites Nanocomposites, Abubkr A. Arzaq Abuhagr

Dissertations

Novel materials such as graphene oxide (GO), reduced graphene oxide (RGO), and Perovskites nanocomposites nanosheets have shown interesting electrical and optical properties. These materials have shown prominence in research regarding optical sensing applications. The interaction of different fluorescent molecules like dye molecules with GO, and RGO have been studied recently to develop novel optical sensors, photo-catalysts, and light-harvesting agents. In this study, we have monitored the excited state interactions of dyes covalently attached to GO and RGO nanosheets. Three amine derivatives of anthracene, pyrene, and coumarin were covalently bound to different systems via amide bonds and diazotization. Characterization of different …

Smart Sensors With Dual Modes Of Signal Transduction For Monitoring Molecules Pertinent To Health And The Environment, Jared T. Wabeke

Dissertations

The dissertation focuses on the design and synthesis of smart materials for the detection of molecules pertinent to environmental protection and healthcare. The use of computational simulations is pivotal toward advancing molecular design for targeted applications. Research was conducted to investigate the use of simulations to develop novel sensors with dual modes of signal transduction. The molecular properties were determined using computational modelling, and then used to elucidate the binding mechanism of the corresponding sensor complexes. Several molecules were produced that respond to important organic analytes, such as glucose and fenthion, an organophosphorus pesticide. Glucose is an exceedingly important biological …

Using Novel Spectroscopy Tool To Study Organized Self-Assemblies, Mohammad Rafe M Bin Hatshan

Dissertations

Organized self-assemblies are the cornerstones for countless biological processes and are integral parts of lipids, proteins, carbohydrates, nucleic acids, and cell membranes. Several man-made organized assemblies also play a vital role in interdisciplinary sciences that include micelles, reverse micelles, polymers, polyelectrolytes etc. Weak chemical interactions such as hydrogen bonding, p-p stacking, hydrophilic-hydrophobic and electrostatics often result in interesting organized self-assemblies. Understanding organized self-assemblies provides a huge opportunity to mimic naturally occurring biological macromolecules, design materials and develop strategies for specific applications. Several techniques are routinely used to understand the organized self-assemblies, and optical techniques play an important role in most …

Improving Protein Analysis By Desorption Electrospray Ionization (Desi-Ms), Elahe Honarvar

Dissertations

Electrospray ionization mass spectrometry (ESI-MS) is one of the most well-known and versatile techniques for analyzing a broad range of molecules and it has become one of the leading techniques to study biomolecules, such as proteins. ESI-MS can accurately determine the molecular weight of proteins and provide information about their peptide sequence, post-translational modifications as well as their interaction with other molecules.

During ESI-MS analysis, by spraying a sample of proteins, prepared in form of a solution, charged droplets are produced using an electric field. As the solvent molecules gradually evaporate from these droplets, freely hovering bare protein ions remain. …

Nanojars: Versatile Platform For Pyrazole Synthesis And Chemistry, And Selective Extraction Of Anions, Basil Mohammed Ahmed

Dissertations

This work is centered around nanojars, a family of nano-sized anion-incarcerating agents. It addresses various aspects of nanojar chemistry, such as synthesis strategies (including green methodologies) for pyrazole ligands needed for the preparation of nanojars, characterization and study of the mechanism of assembly of nanojars, and selective extraction of anions from water using nanojars.

Nanojars are neutral, supramolecular coordination complexes of the general formula [anion⊂ {Cu(μ-OH)(μ-pz)}_n], formed by the reaction of Cu²⁺, HO^‒ and pyrazolate ions (C₃H₂N₂‒, pz^‒) in the presence of oxoanions with large hydration energy …

Elucidation Of The Toxicity Of Anthropogenic Nanoparticles In Environments Containing Heavy Metals, Chartanay Bonner

Dissertations

The design, synthesis, and applications of anthropogenic nanoparticles continue to rise as technologies utilizing the unique chemical and physical properties of materials with nanoscale dimensions emerge. Engineered silver nanoparticles (Ag NPs) possess antimicrobial properties toward several strains of antibiotic-resistant bacteria. The manufacturing and use of Ag NPs have led to their increased presence in the environment as pollutants. The interaction of Ag NPs with other pollutants influence their surface properties, aggregation state, stability and consequently, their toxic response toward microbial pathogens. In the present study, we examined the interaction of heavy metal ions (Cd²⁺, Hg²⁺, and …

Chemotypic Variation Of Biogenic Volatile Organic Compounds In Midwest Forest And Atmospheric Role Of Peroxyacyl Nitrates In Southeastern U.S., Shino Toma

Dissertations

Biogenic volatile organic compounds (VOC), including isoprene and terpenes, impact atmospheric processes such as production of tropospheric ozone, formation and growth of secondary organic aerosol (SOA), global climate change, and human health. Although estimated emission rates of total biogenic VOC exceed anthropogenic emissions, there are many challenges to direct measurements because they are very reactive with atmospheric oxidants and some are still difficult to detect by current analytical techniques. Therefore, high uncertainties lead to discrepancies between individual and total biogenic VOC budget with atmospheric oxidants and an underestimation of SOA formation.

White pine (Pinus strobus) was once a dominant species …

Structures Of Metallacarboranes And Coordination Complexes: Coordination Sensors Based On Rhodamine B And Quinolines, Agozie Nnaemeka Oyeamalu

Dissertations

Rhodamine-based ligands that can complex different metals has been designed and synthesized. Using Rhodamine B as starting material, we synthesized and characterized quinoline precursors as well as successfully carried out the oxidation of methyl and aldehyde groups on the quinoline ring, and on the hydroxyl moiety of the quinoline spirolactone ring. These turn-on/off rhodamine fluorescence probes sense Cr³⁺ and Ni²⁺ with high selectivity and sensitivity. These probes can be applied to detect other metal ions that are present in chemical, biological and environmental settings. They were designed to fluoresce when bonded to ions such as cyanide in detecting …

Biosorption Of Pharmaceuticals And Noble Metals Nanoparticles By Algal Turf Communities, Haider Abid Faraj

Dissertations

Pharmaceuticals and nanoparticles are increasingly released into the aquatic ecosystem, while removing these contaminants from waters can be challenging. This study explores the use of periphytic algal turf communities to remove these contaminants. Initially algal turfs from different locations and aquatic systems were analyzed for pharmaceuticals commonly observed in wastewater outflows. Lab-grown turfs were exposed to a mixture of six representative pharmaceuticals of different functionality (acid, base, neutral and steroidal). Analysis of water column and the algal biomass showed pharmaceutical removal rates varied, specific to each pharmaceutical. Caffeine and estradiol had the highest removal rates while carbamazepine was not removed. …

Preparation Of Aminoalcohols And Their Application For The Synthesis Of Heterocycles And As Potential Sensors For Nerve Agents, David L. Sellers

Dissertations

Oxazoles and oxazolines are important heterocyclic scaffolds commonly used in pharmaceuticals and optoelectronic materials. Traditionally these heterocyclic compounds are prepared by condensation methodology that suffers from poor reactivity when using electron deficient or sterically crowded reaction partners. Condensation methods also exhibit low tolerance of many functional groups as the reactions typically use strong acids and high temperatures. This dissertation describes an alternate strategy for the formation of these compounds by employing an epoxide opening followed by oxidation to form these heterocyclic compounds.

Epoxide opening reactions with primary aliphatic, allylic, and benzylic amines, aminolysis reactions, often achieve high yields regardless of …

N-Terminal Domains Of Copper Atpases In Plasmodium Falciparum, Dictyostelium Dicsoideum, Human Atp7b And A Chimera Of Atox1 With Metal Binding Domain Four Of Atp7b, Javan Kilango Kisaka

Dissertations

Copper transporting ATPases (Cu-ATPases) are essential for mediating copper uptake, maintaining cellular copper levels and prevention of accumulation of toxic copper. The most studied copper ATPases are the Menkes and Wilson proteins in eukaryotes, CopA and CopB found in bacteria. The precise interaction of the metal binding domains with their copper donor, the association of each metal binding domain within the N-terminal portion of the protein, how they communicate with each other, and the eventual metal ion translocation across the membrane, is little known. The variation in number of the cytosolic metal binding domains may also offer clues on the …

Design And Synthesis Of New Non-Steroidal Anti-Inflammatory Drugs With Anti-Cancer Activity On Colon Rectal Cancer Cell Lines Hct-116 And Caco-2, Wanda Ivette Rodríguez Rivera

Dissertations

Colon rectal cancer is one of the most common types of cancer and is the third leading cause of cancer related deaths among western countries. Current chemotherapy treatments are highly toxic and mostly result in only a low percentage of tumor reduction; therefore an effective treatment with low toxicity is needed.

In this study, different innovative new COX-2 inhibitors were synthesized using the frame of biologically active chalcones to which active COX-2 pharmacophores SO₂CH₃, SO₂NH₂, SO₂NHCOCH₃ were added. Additionally, the effect of different alkyl chain lengths and the effect …

Ultrafast Charge Carrier Dynamics In Bare And Surface-Modified Semiconductor Nanoparticles, Jameel Abdul-Hadi Hasan

Dissertations

Charge-carrier relaxation dynamics in semiconductor nanoparticles has been in the forefront of research for last three decades both for their fundamental nature as well as for applications in light-harvesting, luminescent labels, light-emitting diodes and nonlinear optics. Significant research has focused on II-VI semiconductors with emphasis on CdS and CdSe that are toxic. On the other hand, ZnO and TiO2 semiconductor nanoparticles are less toxic and have enormous applications in photo-catalysis, water splitting, solar cells and optical sensors. However, the investigations of charge-carrier dynamics in these semiconductor nanomaterials compared to II-VI semiconductor quantum dots are quite limited. The knowledge of charge-carrier …

Novel Spectroscopic Tools To Differentiate Molecule-Dna Binding Interactions, Sense Dna And Track Dna Melting, Saad Hmoud Alotaibi

Dissertations

The discovery of DNA as a genetic material and its double helical structure led to numerous studies directed at understanding molecule-DNA interactions. These studies have played an integral role in medical diagnostics, forensics, imaging and therapeutics. Typically, molecule-DNA interactions have two prominent modes: intercalation and minor groove binding. Several optical techniques are available that can monitor molecule-DNA binding interactions, but they cannot differentiate between intercalation and minor-groove binding. The major goals of the research are to develop novel optical spectroscopic tools that can differentiate molecule-DNA binding interactions, selectively and sensitively detect one form of DNA over another, and track DNA …

Probing The Unfolding And The Stability Of The Last Four Metal Binding Domains Of Wilson Disease Protein Using Circular Dichroism And Novel Spectroscopic Techniques, Ibtesam Yaseen Alja’Afreh

Dissertations

Wilson disease protein is a copper-transporting P_1B type ATPase. It has large N-terminal copper binding domain which is composed of six homologous sub-domains. Each of these six domains is ~72 residues and connected to one another by linking regions of various lengths. They all possess similar ferrodoxin fold, and metal-binding motif, MXCXXC.

The need of having six metal binding domains and the manner in which they are communicating with each other is not well understood. To better understand how the last four metal binding domains function, I pursued a detailed biophysical characterization of these domains. Using molecular biology I …

Ultrafast Interfacial Electron Transfer Across Molecule-Tio2 Nanocomposites: Towards Solar Cells And Two Photon Absorption, Edwin Mghanga

Dissertations

Interfacial charge transfer (ICT) across the molecule-TiO2 nanoparticle interface has gained enormous research attention for applications in dye sensitized solar cells (DSSC), photo-catalysis, water splitting and nonlinear optics. DSSCs are promising clean alternative energy sources. However, current DSSCs suffer from lower efficiencies and higher cost. Better understanding of the ICT processes in DSSCs can help solve these problems. We have used two strategies to understand ICT in the context of DSSCs. Firstly, we used a computationally validated anchor group, acetylacetonate (acac) to bind molecules to the semiconductor surface and facilitate charge separation. Secondly, we used natural dye sensitizers, …

Biophysical Characterization Of The First Four Metal-Binding Domains Of Human Wilson Disease Protein, Alia V.H. Hinz

Dissertations

Wilson disease protein (WLNP) is a P_1b-type ATPase crucial for maintaining copper homeostasis in humans. Mutations in this protein result in the autosomal recessive disorder Wilson disease, a condition characterized by copper accumulation in the liver and brain. WLNP provides copper for incorporation into cuproproteins and exports excess copper into the bile for excretion. There are six metal-binding domains (MBDs) in WLNP, found within the first 650 amino acids of this 1,465 amino acid protein. Though each MBD has a different amino acid sequence, all MBDs possess a similar ferredoxin fold with a conserved hydrophobic core and a …

Synthesis, Characterization And Potential Applications Of Palladium And Ruthenium Nanostructures, Clara Patrice Adams

Dissertations

Controlling the size and shape of metal nanostructures is important for tuning the intrinsic chemical and physical properties of materials, and consequently their potential technological applications. Modulating the morphology of metal nanostructures is essential to understanding the structure-function relationship (for example, optical, magnetic, catalytic, and electronic properties) under various environmental conditions. Our work describes the development of new procedures for the synthesis of well-defined isotropic and anisotropic nanoparticles consisting of palladium (Pd) and ruthenium (Ru). Characterization of the nanostructures was carried out using transmission electron microscopy (TEM), high resolution-TEM (HRTEM), powder x-ray diffraction (XRD), selected area electron diffraction (SAED) and …

Size-Dependent Interactions Of Metal Nanoparticles With Fluorophores And Semiconductors, Liyana A. Wajira Ariyadasa

Dissertations

In recent years, nanoscale metallic particles have gained considerable interest due to their potential applications in advanced technology. Despite such interest, synthetic procedures that produce gram-scale, well-defined metallic nanoparticles with controlled size and shape, especially with diameters less than 5 nm remains a challenge. Our work has focused on developing synthetic procedures that produce well-defined platinum and palladium metal nanoparticles in the 1-5 nm size range. Thioether ligands were used as stabilizers and resulted in metal nanoparticles with controlled size. The nanoparticles were characterized using transmission electron microscopy (TEM), x-ray diffraction (XRD), selected area electron diffraction (SAED), x-ray photoelectron spectroscopy …

Fundamental Studies Of Protein Ionization For Improved Analysis By Electrospray Ionization Mass Spectrometry And Related Methods, Kevin A. Douglass

Dissertations

Mass spectrometry (MS) is an analytical technique in which a sample is converted to gas-phase ions that are subsequently separated and detected. It offers great speed, selectivity, and sensitivity during analysis, characteristics which have enabled it to become a leading method for the study of proteins. The applications of MS for these biologically significant macromolecules range from accurately determining identity and sequence to shedding light on post-translational modifications and protein-molecule interactions. As a first step towards analysis by MS, gas-phase protein ions must be formed. A common method for ionization is electrospray ionization (ESI), where a liquid sample including the …

Ultrafast Dynamics And Two-Photon Absorption Properties Of Chromophores At Interfaces, Semere Ghebru Bairu

Dissertations

Materials with large two-photon absorption (2PA) cross-sections found applications in several areas such as sensor protection, 3D micro/nano fabrication, photodynamic therapy, optical data-storage, multi-photon sensing, multi-photon microscopy and imaging. Several successful research strategies were developed in literature to achieve 2PA materials with enhanced cross-sections. However, the obtained cross-sections are far from adequate and there is a need to develop new strategies. In a parallel development, numerous research efforts were focused on studying the dynamics of interfacial charge-transfer (ICT) across chromophoresemiconductor interfaces, especially in the context of dye-sensitized solar cells. While investigating the fundamentals of ICT, it was found that these …

Metal-Organic And Supramolecular Architectures Based On Mechanically Interlocked Molecules, Isurika Rosini Fernando

Dissertations

The focus of this work is on mechanically interlocked molecules (MIMs), which have unusual physicochemical and mechanical properties with potential applications in nano-scale/molecular devices and high strength materials.

Rotaxanes, for example, consist of an axle-like molecule threaded through a wheel-like molecule, with bulky groups at the two ends of the axle preventing the wheel from dissociating. The position of the wheel along the axle can be switched in a controllable and reversible manner by applying external stimuli, a feature that might lead to the next generation of computers. Molecularly woven materials (MWMs), another example of molecules with mechanically interlocked features, …

Investigating The Biochemical Activity Of Some Flavonoids, Coumarins And Modified Gold-Nanoparticles As Anti-Breast-Cancer Agents, Amr Ezzat Mohamed Mahmoud

Dissertations

Polyphenols compounds are abundant natural products found in many plants as secondary metabolites. These compounds display many interesting pharmacological activities, which have motivated chemists over the years to explore them, and their synthetic derivatives, as potential drugs, especially anticancer drugs. Breast cancer is the most common cancer in women globally, and in the United States of America the estimated worldwide new breast cancer cases and the number of deaths are 1.38 million and 458 thousand, respectively. Currently in the USA there are 2.6 million women who have been treated for breast cancer, and the estimated number of deaths are 39,520 …

Optical And Electrochemical Sensors For The Detection Of Metal Ions And Nerve Gas Mimics Via Fluorescein And Coumarin Derivatives, Fasil Adefris Abebe

Dissertations

Trace element detection of metals, for example, iron, Copper and zinc, are important in biological systems and in the environment. Many of us are aware that our cells contain metal ions that are “tied” up in proteins. However, chelatable or “free” trace elements can also be found in small quantities, and can have a negative impact on our bodies. Despite the increasing surge in developing sensors for metals and nerve gas agents, efficient detection still remains a challenge. Among the various sensors developed so far, fluorescence sensors play an important role due to their simplicity. I design fluorescein-based chemosensors for …

Optical And Electrochemical Properties Of Monolayer Protected Gold Clusters Modified With Fluorophores, Mary Sajini Devadas

Dissertations

My research focused on the synthesis, characterization and the investigation of the optical and electrochemical properties of monolayer-protected quantum-sized gold clusters. Significant research attention was focused on the solution phase optical and electrochemical properties of these clusters. Highly monodisperse Au clusters with different types of ligands were successfully synthesized with sizes varying from 1 nm to 13 nm. These preformed gold clusters were modified with fluorophores and pseudo-rotaxanes for developing better nonlinear optical materials for sensing and biological imaging purposes. We have tried to focus on the interaction of the outer ligand shell, made up of –S-Au-S-Au-S- bonds, with the …