Digital Commons Network^™

A–C Estrogens As Potent And Selective Estrogen Receptor-Beta Agonists (Serbas) To Enhance Memory Consolidation Under Low-Estrogen Conditions, Alicia M. Hanson, K. L. Iresha Sampathi Perera, Jaekyoon Kim, Rajesh K. Pandey, Noreena Sweeney, Xingyun Lu, Andrea Imhoff, Alexander Craig Mackinnon, Adam J. Wargolet, Rochelle M. Van Hart, Karyn M. Frick, William A. Donaldson, Daniel S. Sem

Chemistry Faculty Research and Publications

Estrogen receptor-beta (ERβ) is a drug target for memory consolidation in postmenopausal women. Herein is reported a series of potent and selective ERβ agonists (SERBAs) with in vivo efficacy that are A–C estrogens, lacking the B and D estrogen rings. The most potent and selective A–C estrogen is selective for activating ER relative to seven other nuclear hormone receptors, with a surprising 750-fold selectivity for the β over α isoform and with EC₅₀s of 20–30 nM in cell-based and direct binding assays. Comparison of potency in different assays suggests that the ER isoform selectivity is related to the …

Detection Of Cyanotoxins (Microcystins/Nodularins) In Hepatic Tissues And Epidermal Mats Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Northeast Florida, Amber Brown

UNF Graduate Theses and Dissertations

The St. Johns River (SJR; Jacksonville, FL, USA) is a large, brackish, estuarine system characterized by considerable anthropogenic pollution, recurrent harmful algal blooms (HABs), and diverse toxin-producing cyanobacteria. The most prevalent toxins in SJR water samples are microcystins/nodularins (MCs/NODs). Additionally, the SJR provides critical habitat for a genetically and behaviorally distinct estuarine community of bottlenose dolphins (Tursiops truncatus) that routinely uses and strands in low mesohaline and oligohaline areas of the river. This population has been subject to two unusual mortality events (UME) since 2010 and has since been described as having substantial declines in population health, characterized …

Crystallographically Defined Silicon Macropore Membranes, Shannon C. Knight, Bret A. Unger, Kurt W. Kolasinski

Chemistry Faculty Publications

Laser ablation with nanosecond-pulsed Nd:YAG laser irradiation combined with anisotropic alkaline etching of Si wafers creates 4–20 µm macropores that extend all the way through the wafer. The walls of these macropores are crystallographically defined by the interaction of the anisotropy of the etchant with the orientation of the single-crystal silicon substrate: rectangular/octagonal on Si(001), parallelepiped on Si(110), triangular/hexagonal on Si(111). Laser ablation can create pillars with peak-tovalley heights of over 100 µm. However, with nanosecondpulsed irradiation at 532 nm, the majority of this height is created by growth above the original plane of the substrate whereas for 355 nm …

Plume And Nanoparticle Formation During Laser Ablation, Kurt W. Kolasinski, Mool C. Gupta, Leonid V. Zhigilei

Chemistry Faculty Publications

The processes that lead to material ejection when a solid sample is irradiated near and above the pulsed laser ablation threshold are discussed. Emphasis is placed on the thermal and mechanical mechanisms that occur during pulsed laser irradiation of metals and semiconductors. Distinctions are drawn between ultrafast-pulsed irradiation, which occurs under stress confinement, and shortpulsed irradiation, in which stress is released during the laser pulse. Similarly, the distinctions between the spallation and phase explosion regimes are discussed. Spallation is only possible when the time of the laser heating is shorter than the time needed for mechanical equilibration of the heated …

Hierarchical Porous Silicon And Porous Silicon Nanowires Produced With Regenerative Electroless Etching (Reetching) And Metal Assisted Catalytic Etching (Mace), Kurt W. Kolasinski, Bret A. Unger, Haibo Yu, Alexis T. Ernst, Mark Aindow, Ermei Mäkilä, Jarno Salonen

Chemistry Faculty Publications

ReEtching produces nanostructured silicon when a catalytic agent, e.g. dissolved V2O5, is used to facilitate etching between Si and H2O2. H2O2 regenerates dissolved V in a 5+ oxidation state, which initiates etching by injecting holes into the Si valence band. Independent control over the extent of reaction (controlled by the amount of H2O2 added) and the rate of reaction (controlled by the rate at which H2O2 is pumped into the etchant solution) allows us to porosify Si substrates of arbitrary size, shape and doping, including wafers, single-crystal powders, polycrystalline powders, metallurgical grade powder, Si nanowires, Si pillars and Si powders …

Silicon Surface Photochemistry, Kurt W. Kolasinski

Chemistry Faculty Publications

General concepts of photochemistry on metal and semiconductor surfaces are elucidated. These concepts are then applied more specifically to describe photochemical transformation of molecules on and with silicon surfaces. The mechanisms by which light can induce chemical reactions following electronic excitation are described. Processes reviewed include photodissociation of adsorbed molecules, photo-induced attachment of organic molecules and photo-induced corrosion.

Polyelectrolyte Complexes Based On Poly(Acrylic Acid): Mechanics And Applications, Xiaoyan Lu

Electronic Theses and Dissertations

Poly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic condition when the carboxylic group loses a proton. These carboxylate group can interact with polycations and metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable properties and multifunctional nanoscale structures through chemical reactions. This research focuses on nanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferric ion concentration on the mechanical properties of PAA-based single naonofiber by using dark field microscopy imaging and persistence length analysis. The application of PAA-based nanofiber mats loaded with MnO2 for supercapacitors was also explored. As a …

In Situ Treatment Systems For Remediation Of Polychlorinated Biphenyl-Contaminated Building Materials, Adibah Almutairi

Electronic Theses and Dissertations

Polychlorinated Biphenyls (PCBs) are a family of synthetic organohalides comprising 209 congeners which were used historically as additives in paint and caulking materials over a span of many years. Even though the production of PCBs in the USA has been banned since the late 1970s, their former prevalence and widespread use means many structures are still coated with PCB-laden paints. In addition, the presence of PCBs in elastic sealants has resulted in transport of PCBs into concrete structures and has caused soil contamination around buildings. PCB-contaminated building materials have become a significant concern for the environment and building occupants due …

Light Scattering Property Of Gold Nanoparticles With Applications To Biomolecule Detection And Analysis, Tianyu Zheng

Electronic Theses and Dissertations

Gold nanoparticles (AuNPs) have unique optical and chemical properties. Dynamic light scattering (DLS) is an analytical tool used routinely for nanoparticle size measurement. The combined use of AuNPs and DLS has led to a novel analytical assay technology called D2Dx (from diameter to diagnostics). Herein, my dissertation highlights the extended use of D2Dx for biomolecule detection and analysis. Under this general theme, Chapter 1 provides some background information of AuNPs, DLS, the principle of D2Dx technique and its potential applications. Chapter 2 summarizes a study on the effect of AuNP concentrations and laser power on the hydrodynamic size measurement of …

Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter

Faculty & Staff Scholarship

Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N- terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteina- ceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions …

Evidence That Speciation Of Oxovanadium Complexes Does Not Solely Account For Inhibition Of Leishmania Acid Phosphatases, Benjamin M. Dorsey, Craig C. Mclauchlan, Marjorie A. Jones

Faculty Publications – Chemistry

Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, …

Structural Identification And Kinetic Analysis Of The In Vitro Products Formed By Reaction Of Bisphenol A‑3,4-Quinone With N‑Acetylcysteine And Glutathione, Douglas E. Stack, John A. Conrad, Bejan Mahmud

Chemistry Faculty Publications

Bisphenol A (BPA) has received considerable attention as an endocrine disrupting chemical and a possible substrate for genotoxic metabolites. BPA metabolism leads to formation of electrophilic o-quinones cable of binding to DNA and other endogenous nucleophiles. We have structurally identified the products resulting from the reaction of bisphenol A-3,4-quinone (BPAQ) with N-acetylcysteine (NAC) and glutathione (GSH). The major and minor isomers are both the result of 1,6-conjugate addition and are produced almost instantly in high yield. Reactions using 1.3 equiv of GSH showed the presence of a bis-glutathionyl adduct which was not observed using higher GSH concentration relative to BPAQ. …

Prediction Of Novel Anti-Ebola Virus Compounds Utilizing Artificial Neural Network (Ann), Ronald Bartzatt

Chemistry Faculty Publications

Artificial Neural Network (ANN) analysis is shown to predict the molecular properties of new anti-EBOLA compounds following training/learning by use of 60 previously known and studied drugs. Following training/learning by applying properties of 60 known drugs the TIBERIUS ANN system can efficiently predict the molecular properties of comparable new drugs. Molecular weight (MW) is an important and dominant property of perspective drugs considered for clinical trials. TIBERIUS ANN was able to predict comparable values of MW for drugs following training cycles. One-way ANOVA, F and T tests indicate that actual and predicted MW have the same means (P=.99). Passing-Bablok regression …

Chalcogen Impact On Covalency Within Molecular [Cu3(Μ3-E)]3+ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, And Computational Study, B. J. Cook, G. N. Di Francesco, R. B. Ferreira, J. T. Lukens, K. E. Silberstein, B. C. Keegan, V. J. Catalano, K. M. Lancaster, Jason M. Shearer, L. J. Murray

Chemistry Faculty Research

Reaction of the tricopper(I)-dinitrogen tris(β-diketiminate) cyclophane, Cu₃(N₂)L, with O-atom-transfer reagents or elemental Se affords the oxido-bridged tricopper complex Cu₃(μ₃-O)L (2) or the corresponding Cu₃(μ₃-Se)L (4), respectively. For 2 and 4, incorporation of the bridging chalcogen donor was supported by electrospray ionization mass spectrometry and K-edge X-ray absorption spectroscopy (XAS) data. Cu L_2,3-edge X-ray absorption data quantify 49.5% Cu 3d character in the lowest unoccupied molecular orbital of 2, with Cu 3d participation decreasing to 33.0% in 4 and 40.8% in the related sulfide cluster Cu_{3 …}

Exposure Of Kidney Bean (Phaseolus Vulgaris) Plants To Coated And Uncoated Zinc Oxide Nanomaterials Under Different Soil Conditions: Effects On Plant Growth And Seed Quality, Illya Aidee Medina Velo

Open Access Theses & Dissertations

Soil exposure to engineered nanomaterials (NMs) occurs through the intentional use of nano-agrochemicals, incidental contamination from industrial-waste release, irrigation with wastewater and gray water, or amendment with NM-loaded sludge. Although there are several reports about the effects of NMs in terrestrial plants, there is still a lack of knowledge about the effects of NMs in crop plants and their edible portions.

Among the large list of produced NMs, it is estimated that 34,000 tons of ZnO NMs are produced yearly. Due to their growing applications in cosmetics and personal care products, there is a high possibility that the ZnO NMs …

Antibiotic Effects Of Dimethyl Sulfoxide And Synthetic Polyphenols On E. Coli Cells, Camila Cardenas

Theses and Dissertations

There is increasing interest in polyphenols due to their potential medicinal and antibiotic applications. Naturally occurring polyphenols, such as curcumin, have garnered tremendous attention. However, synthetic polyphenols commonly used in biochemistry experiments have not been sufficiently explored. The purpose of this study is to determine the effect of dimethyl sulfoxide on the cellular uptake of synthetic polyphenols. Three synthetic polyphenols (Phenol Red, Congo Red, and Bromophenol Blue) were tested for their antibiotic properties and compared to the antibiotic activity of curcumin. Our results show that phenol red does not interact with the bacterial membrane even in the presence of 30% …

Development And Characterization Of A Paper Based Analytical Device For Heparin Quantification, Carolanne Norris

Undergraduate Honors Thesis Projects

Paper-based analytical devices (PAD) have gained popularity in the past ten to fifteen years due to many favorable mechanical properties.1 They have largely been used to analyze small ionic species, such as Na+ and Li+, but little research has been done on their capability of to analyze large polyionic species, for instance the highly sulfonated polysaccharide heparin.2,3 This study explores adaptation of a traditional optode design to a low cost PAD that employs a smartphone as a detector. Throughout the study variables, such as membrane composition, pH, volume of solution, time, addition of a polymer, use of different cell phone …

Synthesis Of 2-Substituted 8-Propargyloxyquinoline Derivatives And Determination Of Their Antioxidant, Antibacterial, And Dna Binding Activities, Ayşegül Gümüş, Veysi̇ Okumuş, Selçuk Gümüş

Turkish Journal of Chemistry

2-Substituted 8-propargyloxyquinoline derivatives have been synthesized from 2-substituted-8-hydroxyquinolines by O-propargylation method (30%-98% yields). The newly synthesized compounds were tested for in vitro antioxidant activities such as DPPH radical scavenging, ferrous chelating, and reducing power activities. The maximum radical scavenging (46.5%) and reducing power activities were obtained from 1 and maximum ferrous chelating effect was obtained from 6 (72.1%) at the concentration of 500 $\mu $g/mL. To indicate DNA binding activity of the complexes calf thymus DNA was used. The compounds were also evaluated for their antimicrobial activity against three gram-positive and three gram-negative bacteria. Compounds 3 and 5 exhibited antibacterial …

Direct Measurement Of Rupture Force Of Single Triazole Molecule By Atomic Force Microscope And Solid Phase Synthesis Of Monodisperse Polyethylene Glycols, Ashok Khanal

Dissertations, Master's Theses and Master's Reports

This dissertation includes two topics, which are related to each other: (1) Rupture force measurement of single triazole molecule by atomic force microscope (AFM) and (2) Solid phase stepwise synthesis of polyethylene glycols (PEGs).

The reaction of an alkyne and an azide to form a 1,2,3- triazole has found wide applications. However, the stability of triazole under mechanical stress is unclear. We investigated the cycloreversion at the single molecular level using atomic force microscopy. A mica surface functionalized with a molecule containing a 1,2,3-triazole moiety in the middle and an activated ester at the end was prepared. An AFM tip …

Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar

Dissertations, Master's Theses and Master's Reports

Wildfires are episodic disturbances that exert a significant influence on the Earth system. They emit substantial amounts of atmospheric pollutants, which can impact atmospheric chemistry/composition and the Earth’s climate at the global and regional scales. This work presents a collection of studies aimed at better estimating wildfire emissions of atmospheric pollutants, quantifying their impacts on remote ecosystems and determining the implications of 2000s-2050s global environmental change (land use/land cover, climate) for wildfire emissions following the Intergovernmental Panel on Climate Change (IPCC) A1B socioeconomic scenario.

A global fire emissions model is developed to compile global wildfire emission inventories for major atmospheric …

Block-Copolymer Assisted Fabrication Of Anisotropic Plasmonic Nanostructures, Calbi J. Gunder

Graduate Theses/Dissertations

The anisotropic nanostructures of noble metals are of great interest for plasmonic applications due to the possibility of tuning the localized surface plasmon resonance (LSPR) across the UV-VIS-NIR without sacrificing the linewidth as well as to achieve larger local field enhancement. Here, we report a simple and promising fabrication method of anisotropic gold nanostructures film using polystyrene-b-2vinylpyridine (PS-b-P2VP) block copolymers (BCP) as a template. In this approach, PS-b-P2VP spherical micelles were first synthesized as a template followed by selective deposition of Au precursor inside P2VP core of the micelles using ethanol solution of Au salt. Subsequently, heat treatment of the …

Environmental Impact Assessment Of Pinaceae Airborne Pollen And Green Infrastructure Using Bim, Santiago Fernández-Rodríguez, Juan Pedro Cortés-Pérez, Paloma Prieto Muriel, Rafael Tormo-Molina, J. M. Maya-Manzano

Articles

Urban air quality is a parameter that plays a major role in human health at the local scale. Consequently, in urban planning, the behavior and potential risk of allergenicity for some pollen grains coming from ornamental trees and green spaces surrounding newly built buildings, should be considered. This paper aims to study how pollen exposure, influenced by weather parameters, can be assessed and integrated in the designing and building of constructions as other component of air quality assessment beforehand, by using BIM. Based on a comparative aerobiological study at the height over a building (sampled by two traps at ground …

Cascade Annulation And Ring-Opening Reactions Of Castagnoli-Cushman-Derived Allylic And Benzylic Thiomorpholinonates, Abdikani Omar Farah

All Master's Theses

Sulfur-containing compounds are prevalent in antibiotics, essential amino acids, bacterial RNA, food flavors, and enzymes. The divalent sulfur atom introduces a metabolic liability from a drug discovery standpoint. Indeed, it is quite telling that all the top ten best-selling drugs in 2012 contained sulfur. In this context, there is a growing need for the synthesis of sulfur-containing compounds in ways that are practical and cost-effective. One approach taken to achieve this goal is to employ diversity-oriented synthesis (DOS), which produces diverse complex molecules with similar core structures from a common precursor. When a DOS features a cascade or domino reaction …

Characterization Of Coacervate Systems Using Redox Sensitive Dyes, Caleb Kaiser

All Master's Theses

Coacervates are systems that spontaneously form when two oppositely charged polyelectrolytes are mixed in a concentrated salt solution. When coacervates form, a biphasic equilibrium occurs in the sample with two phases present in the solution. The two phases are described as the dense phase and the lean phase, named after the amount of polyelectrolyte material in each phase. Coacervates have been topics of interest to researchers in a variety of fields including biomedical applications, drug delivery devices, and more. This thesis worked towards the characterization of coacervate systems on the molecular level by investigating the interaction of the polyelectrolytes and …

Determination Of The Oxidative Capacity Of Soot Toward Gsh And Characterization Of Soot Physicochemical Properties, Kaylee Troth

All Master's Theses

Fine atmospheric particulate matter (PM_2.5) emitted during the combustion of fossil and biomass fuels is known to adversely affect human health. While the underlying mechanisms are thought to be driven by the generation of reactive oxygen species (ROS), specific particle characteristics responsible for this detrimental effect are not well understood. In this research, the quantitative determination of the biologically relevant antioxidant, glutathione (GSH), was optimized for use as an indicator of oxidative stress to shed light on relevant particle characteristics. This was accomplished via fluorescent spectroscopy for GSH determination by way of reaction with o-phthalaldehyde (OPA), a …

Theoretical Circular Dichroism Spectra Of The Α-Helical Protein Calexitin With The Dipole Interaction Model Including The N-Π* Transition, Akongnwi C. Jungong, Tsvetan Aleksandrov, Rahul Nori, Justin Erickson, Kathryn A. Thomasson, Igor V. Uporov, Ethan R. Austhof, Emily Holt, Felix N. Ngassa

Chemistry Faculty Publications

Circular dichroism (CD) is an important structural biology technique used to study protein dynamics, and most especially the secondary structure of peptides and proteins. Although CD is a technique that is relatively easy to introduce to undergraduate students, the high cost of obtaining a conventional CD instrument and the time required for sample preparation prevents a good number of students from having hands-on experiments demonstrating the principle of CD. Herein, theoretical circular dichroism with the dipole interaction model, DInaMo, is proposed as a tool for introducing students to CD. Using the dipole interaction model, the CD spectra of an α-helical …

Targeting Metastatic Breast Cancer With Statin Drugs And Coq10, Jacob Thrasher

Honors Theses

Statin drugs are commonly prescribed to lower cholesterol levels in patients, but recently statins have been under investigation as a potential anti-cancer drug. Statins are HMG-CoA reductase inhibitors and subsequently inhibit the mevalonate pathway and cholesterol synthesis. Since cholesterol trafficking is vital in the growth and metastasis of cancer, statin drugs are being studied to explore their effects on cancer cells. CoQ10, one of the products from the mevalonate pathway, also has shown some potential anti-cancer properties, but its use to combat cancer is controversial. While some studies have shown that CoQ10 supplements can be synergistic with other cancer treatment …

Heterobifunctional Linear Dendritic Block Co-Polymers (Ldbcs) As Multifunctional Carriers For Targeted Drug Delivery, William Rieger

Honors Theses

Despite current research towards applications of polymeric drug delivery systems (DDSs) in biomedical research, significant limitations—specifically in synthetic accessibility, bio compatibility, and principles of molecular self-assembly—have been discerned. To address these drawbacks, we will investigate the synthesis and characterization of heterobifunctional linear-dendritic block copolymers (LDBCs), which combine the advantageous properties of both linear and dendritic blocks to afford nanomaterials with superior mechanical properties. Our LDBC systems contain two differing functional constituents, namely a hydrophilic polyamidoamine (PAMAM) dendron covalently linked to a hydrophobic polyester (polylactic acid, or PLA), and can self-assemble to form nanoparticles of various morphologies that serve as the …

Cell-Free Telomere Dna As A Biomarker For Treatment Response And Tumor Burden In Glioblastoma, John P. North

Honors Theses

Telomeres are repeated nucleotide sequences that cap the ends of each chromosome in eukaryotes. Telomeres are among the earliest genomic sequences to be degraded during apoptosis, potentially providing a biomarker of cell death. To study this, we quantified telomeres in serum from Glioblastoma and non-cancer patients. Cell-free DNA was isolated by centrifugation to remove intact cells, and purified using a QIAamp DNA Blood Midi Kit (Qiagen). Cell-free telomeric (cf-tel) and cell-free actin (cf-actin) DNA were analyzed with quantitative PCR. Total cell-free DNA was measured with PicoGreen assays. We hypothesize that patients with Glioblastoma tumors have higher cf-tel DNA levels than …

Electrocatalytic Oxygen Reduction Studies On Gold Nanoparticles, Leigh Sumner

Honors Theses

After determining that the size of nanoclusters can be tuned such that they have a precise formula much like a chemical compound, much is still not known about nanoclusters, their properties, and how they interact if core size, ligand, and even environment is changed. One such mystery is how does the size of the nanoparticle tune its ability as a catalyst. As it is known that nanoparticles possess unique properties, studies have begun to look towards nanoclusters as catalysts for alternative forms of energy. Therefore, determining how size affects the ability of a nanoparticle catalyst becomes a very important question. …