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Title: SPLIT PROBE DETECTION OF THE INFLUENZA A VIRUS FOR IMPROVED DIAGNOSTICS IN A POINT OF CARE SYSTEM.
Creator: Yishay, Tamar, Gerasimova, Yulia, Harper, James, University of Central Florida
Abstract / Description: A group of Influenza viruses, RNA containing viruses of the Orthomyxoviridae family, consists of Influenza virus types A-D and has been known to cause the Flu, a respiratory illness associated with numerous detrimental symptoms that can lead to death. Influenza A virus (IAV) is constantly changing and is capable of causing pandemics. Currently used diagnostic methods include virus culturing, immunoassays including rapid influenza detection tests (RIDTs), and molecular assays including those...
Show moreA group of Influenza viruses, RNA containing viruses of the Orthomyxoviridae family, consists of Influenza virus types A-D and has been known to cause the Flu, a respiratory illness associated with numerous detrimental symptoms that can lead to death. Influenza A virus (IAV) is constantly changing and is capable of causing pandemics. Currently used diagnostic methods include virus culturing, immunoassays including rapid influenza detection tests (RIDTs), and molecular assays including those based on RT-PCR. Most of the methods can be only performed in the certified diagnostic laboratories equipped with sophisticated instrumentation and/or special biosafety facilities. The results using these methods are not available on a timely basis. RIDTs provide response within 15 minutes but are unable to differentiate between the IAV subtypes. New diagnostic technique, which allows reliable detection of the influenza virus infection and virus genotyping at point-of-care setting, are needed to prevent the spread of the virus and the occurrence of a pandemic. In this project, we propose to use split G-quadruplex (G4) peroxidase probes targeting a fragment of the IAV genome amplified using an isothermal RNA amplification reaction for the detection of IAV infection and virus genotyping. The probes selectively report the virus RNA target with a color change, which can be read by the naked eye. They are capable of differentiating the targets containing as little as a single-nucleotide variation in their sequences. This study aims to optimize the probes, test their selectivity, and calculate the detection limit.
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Date Issued: 2019
Identifier: CFH2000533, ucf:45639
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000533

Title: The Owl Sensor: a smart nanostructure for single nucleotide variation analysis.
Creator: Karadeema, Rebekah, Kolpashchikov, Dmitry, Chumbimuni Torres, Karin, Harper, James, University of Central Florida
Abstract / Description: Analysis of single nucleotide variations (SNVs) in DNA and RNA sequences is extensively used in healthcare for detection of genetic mutations and analysis of drug resistant pathogens. Here we developed a nucleic acid sensor able to differentiate between a fully matched analyte and one with a SNV in a wide temperature range of 5(&)deg;C-32(&)deg;C. The sensor, dubbed here the 'Owl Sensor' due to the complex's resemblance to owl eyes, utilizes recent developments in DNA nanotechnology and...
Show moreAnalysis of single nucleotide variations (SNVs) in DNA and RNA sequences is extensively used in healthcare for detection of genetic mutations and analysis of drug resistant pathogens. Here we developed a nucleic acid sensor able to differentiate between a fully matched analyte and one with a SNV in a wide temperature range of 5(&)deg;C-32(&)deg;C. The sensor, dubbed here the 'Owl Sensor' due to the complex's resemblance to owl eyes, utilizes recent developments in DNA nanotechnology and synthetic biology to self-assemble a fluorescent DNA nanostructure called a Double Crossover, or DX Tile, capable of differentiating SNVs in a large temperature range, including ambient temperature. In the presence of fully matched nucleic acid analytes, a stable complex is formed with high fluorescent signal; however in the presence of a single base variation in the analyte, unfavourable helicity results in little-to-no observed complex formation. The novelty of the approach is that selectivity of analyte recognition is, at least in part, determined by the structural rigidity of the entire nanostructure rather than by the stability of analyte-probe hybrid, as is the case for conventional hybridization probes. The rigid nanostructure collapses if a minor imperfection, e.g. if a single-base mispairing, is present. Owl Sensor differentiates fully matched analyte from mismatched in a wide temperature range, with mismatched analyte producing only the background fluorescence, selectivity that is hard to achieve by conventional hybridization probes. Owl Sensor therefore promises to add to the toolbox for diagnosis of genetic disorders and infectious diseases at ambient temperatures.
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Date Issued: 2016
Identifier: CFE0006691, ucf:51916
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006691

Title: It takes two to tango: the toxin-chaperone relationship.
Creator: Kellner, Alisha, Teter, Kenneth, Moore, Sean, Cole, Alexander, Harper, James, University of Central Florida
Abstract / Description: Cholera toxin (CT) enters the cell via receptor-mediated endocytosis and travels in a retrograde fashion to the endoplasmic reticulum (ER). The catalytic A1 subunit (CTA1) is then displaced from the rest of the holotoxin, unfolds, and is exported to the cytosol where it regains an active conformation for the ADP-ribosylation of its G-protein target. We have shown that the cytosolic chaperones Hsp90 and Hsc70 are required for CTA1 translocation to the cytosol. We have also shown that both are...
Show moreCholera toxin (CT) enters the cell via receptor-mediated endocytosis and travels in a retrograde fashion to the endoplasmic reticulum (ER). The catalytic A1 subunit (CTA1) is then displaced from the rest of the holotoxin, unfolds, and is exported to the cytosol where it regains an active conformation for the ADP-ribosylation of its G-protein target. We have shown that the cytosolic chaperones Hsp90 and Hsc70 are required for CTA1 translocation to the cytosol. We have also shown that both are able to independently bind and refold CTA1. Using libraries of CTA1-derived peptides, we have identified a single Hsc70 binding site, YYIYVI (CTA1 83-88), within the 192 amino acid protein, as well as two distinct Hsp90 binding sites: an N-terminal RPPDEI (CTA111-16) motif and a C-terminal LDIAPA (CTA1 153-158) motif. The LDIAPA motif is unique to CTA1, but an RPPDEI-like motif is present in four other ER-translocating ADP-ribosylating toxins: pertussis toxin, Pseudomonas aeruginosa exotoxin A, Escherichia coli heat-labile toxin, and Salmonella typhimurium ADP-ribosylating toxin. Using site-directed mutagenesis to further investigate the RPPDEI motif, we found that a modification of either proline residue blocks CTA1 translocation to the cytosol. Our work has identified, for the first time, specific amino acid sequences that are recognized by Hsp90/Hsc70 and are essential for toxin translocation from the ER to the cytosol. CT does not require prolyl isomerases for cellular activity, as is the case for Hsp90-dependent endosome-translocating toxins. We therefore hypothesize that the one or both of the prolines within the RPPDEI motif of CTA1 undergo an isomerization event as CTA1 unfolds in the ER. Furthermore, we predict that the trans- to cis- conformational change of proline(s) is the molecular determinate for the atypical Hsp90 interaction observed with CTA1 and related toxins. Additionally, we have identified Hsp90 and other host factors required for the translocation of pertussis toxin.
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Date Issued: 2019
Identifier: CFE0007661, ucf:52500
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007661

Title: Synthesis, linear and nonlinear photophysical characterization of two symmetrical pyrene-terminated squaraine derivatives in solution.
Creator: Ballestas Barrientos, Alfonso, Belfield, Kevin, Harper, James, Clausen, Christian, University of Central Florida
Abstract / Description: Two indole-based squaraine dyes bonded to two pyrenyl groups through vinyl- and ethynyl- linkers were synthesized with the aim of enhancing the intramolecular charge transfer interaction in addition to improving their optical properties. The absorption and emission properties of these derivatives were determined in order to gain an insight into the intensity of this type of interaction, their aggregation behavior and compare them with results obtained through quantum chemical calculations....
Show moreTwo indole-based squaraine dyes bonded to two pyrenyl groups through vinyl- and ethynyl- linkers were synthesized with the aim of enhancing the intramolecular charge transfer interaction in addition to improving their optical properties. The absorption and emission properties of these derivatives were determined in order to gain an insight into the intensity of this type of interaction, their aggregation behavior and compare them with results obtained through quantum chemical calculations. Both compounds presented high photochemical stability in THF, and the linear spectroscopic characterization revealed high extinction coefficients, large fluorescence quantum yields and relatively low tendency of forming excimers in several solvents. The nonlinear spectroscopic study revealed two-photon absorption cross section maxima greater than 10,000 GM (1 GM = 1 (&)#215; 10-50 cm4 s/photon), which are improved values in comparison with the indole-based squaraine core. The experimental results were compared with time-dependent DFT calculations. These observations propose a new trend in the formulation of highly absorbing organic molecules containing pyrenyl groups for the development of new materials with Organic Light-Emitting Diode (OLED) applications. Moreover, this work contributes to the study of intramolecular charge transfer interaction and its tailoring for the improvement of the linear and nonlinear optical properties.
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Date Issued: 2015
Identifier: CFE0006024, ucf:50999
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006024

Title: Optical Properties of Single Nanoparticles and Two-dimensional Arrays of Plasmonic Nanostructures.
Creator: Zhou, Yadong, Zou, Shengli, Harper, James, Zhai, Lei, Chen, Gang, Zheng, Qipeng, University of Central Florida
Abstract / Description: The tunability of plasmonic properties of nanomaterials makes them promising in many applications such as molecular detection, spectroscopy techniques, solar energy materials, etc. In the thesis, we mainly focus on the interaction between light with single nanoparticles and two-dimensional plasmonic nanostructures using electrodynamic methods. The fundamental equations of electromagnetic theory: Maxwell's equations are revisited to solve the problems of light-matter interaction, particularly...
Show moreThe tunability of plasmonic properties of nanomaterials makes them promising in many applications such as molecular detection, spectroscopy techniques, solar energy materials, etc. In the thesis, we mainly focus on the interaction between light with single nanoparticles and two-dimensional plasmonic nanostructures using electrodynamic methods. The fundamental equations of electromagnetic theory: Maxwell's equations are revisited to solve the problems of light-matter interaction, particularly the interaction of light and noble nanomaterials, such as gold and silver. In Chapter 1, Stokes parameters that describe the polarization states of electromagnetic wave are presented. The scattering and absorption of a particle with an arbitrary shape are discussed. In Chapter 2, several computational methods for solving the optical response of nanomaterials when they are illuminated by incident light are studied, which include the Discrete Dipole Approximation (DDA) method, the coupled dipole (CD) method, etc. In Chapter 3, the failure and reexamination of the relation between the Raman enhancement factor and local enhanced electric field intensity is investigated by placing a molecular dipole in the vicinity of a silver rod. Using a silver rod and a molecular dipole, we demonstrate that the relation generated using a spherical nanoparticle cannot simply be applied to systems with particles of different shapes. In Chapter 4, a silver film with switchable total transmission/reflection is discussed. The film is composed of two-dimensional rectangular prisms. The factors affecting the transmission (reflection) as well as the mechanisms leading to the phenomena are studied. Later, in Chapter 5 and 6, the sandwiched nano-film composed of two 2D rectangular prisms arrays and two glass substrates with a continuous film in between is examined to enhance the transmission of the continuous silver film.
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Date Issued: 2018
Identifier: CFE0007117, ucf:51943
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007117

Title: Catalyst Design and Mechanism Study with Computational Method for Small Molecule Activation.
Creator: Liu, Muqiong, Zou, Shengli, Harper, James, Dixon, Donovan, Chen, Gang, Feng, Xiaofeng, University of Central Florida
Abstract / Description: Computational chemistry is a branch of modern chemistry that utilizes the computers to solve chemical problems. The fundamental of computational chemistry is Schr(&)#246;dinger equation. To solve the equation, researchers developed many methods based on Born-Oppenheimer Approximation, such as Hartree-Fock method and DFT method, etc. Computational chemistry is now widely used on reaction mechanism study and new chemical designing.In the first project described in Chapter 3, we designed...
Show moreComputational chemistry is a branch of modern chemistry that utilizes the computers to solve chemical problems. The fundamental of computational chemistry is Schr(&)#246;dinger equation. To solve the equation, researchers developed many methods based on Born-Oppenheimer Approximation, such as Hartree-Fock method and DFT method, etc. Computational chemistry is now widely used on reaction mechanism study and new chemical designing.In the first project described in Chapter 3, we designed phosphine oxide modified Ag3, Au3 and Cu3 nanocluster catalysts with DFT method. We found that these catalysts were able to catalyze the activation of H2 by cleaving the H-H bond asymmetrically. The activated catalyst-2H complex can be further used as reducing agent to hydrogenate CO molecule to afford HCHO. The mechanism study of these catalysts showed that the electron transfer from electron-rich metal clusters to O atom on the phosphine oxide ligand is the major driving force for H2 activation. In addition, different substituent groups on phosphine oxide ligand were tested. Both H affinity of metal and the substituent groups on ligand can both affect the activation energy.Another project described in Chapter 4 is the modelling of catalyst with DFT. We chose borane/NHC frustrated Lewis pair (FLP) catalyzed methane activation reaction as example to establish a relationship between activation energy and catalysts' physical properties. After performing simulation, we further proved the well-accepted theory that the electron transfer is the main driving force of catalysis. Furthermore, we were able to establish a linearivrelationship for each borane between activation energy and the geometrical mean value of HOMO/LUMO energy gap (?EMO). Based on that, we introduced the formation energy of borane/NHC complex (?EF) and successfully established a generalized relationship between Ea and geometrical mean value of ?EMO and ?EF. This model can be used to predict reactivity of catalysts.
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Date Issued: 2018
Identifier: CFE0007343, ucf:52112
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007343

Title: Time-Resolved Phosphorescence Spectroscopy at Cryogenic Temperatures for the Environmental Analysis of Polycyclic Aromatic Sulfur Heterocycles in Oil Contaminated Sites.
Creator: Al Tameemi, Maha, Campiglia, Andres, Zou, Shengli, Harper, James, Heider, Emily, Coffey, Kevin, University of Central Florida
Abstract / Description: The large volume of crude oil released into the Gulf of Mexico by the Deepwater Horizon (DWH) accident has raised considerable concerns over potential ecosystem impacts. The dispersion of harmful oil components into the ocean waters could pose long term risks to flora and fauna. Due to the complexity of oil contaminated sites, the unambiguous identification and quantitation of environmental pollutants often requires the sequence of high-performance liquid chromatography (HPLC) and gas...
Show moreThe large volume of crude oil released into the Gulf of Mexico by the Deepwater Horizon (DWH) accident has raised considerable concerns over potential ecosystem impacts. The dispersion of harmful oil components into the ocean waters could pose long term risks to flora and fauna. Due to the complexity of oil contaminated sites, the unambiguous identification and quantitation of environmental pollutants often requires the sequence of high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). A classic example is the analysis of the sixteen polycyclic aromatic hydrocarbons included in the priority pollutants list of the U.S. Environmental Protection Agency (EPA-PAHs).This dissertation tackles a different aspect of environmental analysis as is focuses on the photoluminescence spectroscopy of polycyclic aromatic sulfur heterocycles (PASHs). Since considering the EPA-PAHs alone can lead to drastic underestimations of potential toxic effects of oil spills, a strong case can be made for including hetero-aromatic compounds in risk assessments of contaminated sites. PASHs exist in an even greater variety of chemical structures than PAHs and, because of the asymmetry imposed by the heteroatom, the number of PASHs isomers is usually large. The existence of numerous isomers of the same molecular weight increases the difficulty of separation and identification by chromatographic methods.This dissertation demonstrates the capability to differentiate individual PASHs isomers of MW 234 g mol-1 via vibrational spectroscopy at liquid nitrogen (77 K) and liquid helium (4.2K) temperatures. Fluorescence and phosphorescence spectra are presented for isomer determination at the parts-per-billion (ng. mL-1) concentration levels. It is demonstrated that the relatively long phosphorescence decays of PASHs facilitate the time discrimination of strong fluorescence.interference from PAHs and methylated-PAHs often present in Normal-Phase HPLC fractions. The spectral and lifetime databases compiled in this dissertation have paved the road to explore the full dimensionality of photoluminescence spectroscopy.
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Date Issued: 2017
Identifier: CFE0007275, ucf:52183
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007275

Title: Novel Fuel-producing Fungi and Methodologies for Increasing Fuel Production.
Creator: Wang, Yuemin, Harper, James, Bridge, Candice, Frazer, Andrew, Beazley, Melanie, Blair, Richard, University of Central Florida
Abstract / Description: An endophytic fungus Hypoxylon sp. (BS15) has recently been isolated and found to produce volatile organic compounds (VOCs) that have potential relevance as hydrocarbon fuels. In the work described here, the traditional refined carbohydrate (e.g., sucrose) diet source was replaced by simple sugars produced using a solvent free green chemistry mechanocatalytic method involving ball milling in the solid. BS15 is able to grow on this degraded cellulose as well as the more traditional potato...
Show moreAn endophytic fungus Hypoxylon sp. (BS15) has recently been isolated and found to produce volatile organic compounds (VOCs) that have potential relevance as hydrocarbon fuels. In the work described here, the traditional refined carbohydrate (e.g., sucrose) diet source was replaced by simple sugars produced using a solvent free green chemistry mechanocatalytic method involving ball milling in the solid. BS15 is able to grow on this degraded cellulose as well as the more traditional potato dextrose broth. The volatile compounds produced from both media were largely the same. Unfortunately, it is observed that long term in vitro growth of BS15 results in diminished VOC production. The VOC production was partially restored by cultivating BS15 in growth media containing finely ground woody tissue from the original host plant (Taxodium distichum). Extracts from this woody tissue were made by sequentially extracting with dichloromethane, methanol, and water with a goal of isolating VOC production modulators. Both the dichloromethane and water extracts place on bio-mimicking filter paper were found to modulate VOC production, while the methanol extract had no significant impact. Surprisingly, the woody tissue remaining after exhaustive extraction also acted as a VOC production modulator when combined with the growth media, with noticeable changes in the production of four compounds. This woody tissue also induced production of two compounds not observed in the original BS15 extract, and their changes are inheritable. Remarkably filter paper had the same modulating effect as exhaustively extracted woody tissue, suggesting the modulation was partially due to cellulose degradation products. Extraction of the maximum amounts of VOCs is desirable and here a comparison of solid phase extraction (SPE) and solid phase micro-extraction (SPME) techniques is made. This comparison involves two endophytes, BS15C and Streptomyces ambofaciens (SA 40053). The SPE technique is more effective in retaining compounds having lower vapor pressures and higher boiling points with nearly three to five times more VOC mass obtained versus SPME.
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Date Issued: 2019
Identifier: CFE0007552, ucf:52598
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007552

Title: Detection of Mercury Through Surface Plasmon Resonance of Immobilized Gold Nanorods.
Creator: Trieu, Khang, Campiglia, Andres, Rex, Matthew, Heider, Emily, Frazer, Andrew, Harper, James, Bhattacharya, Aniket, University of Central Florida
Abstract / Description: Mercury is a known environmental pollutant that can damage the brain, heart, kidney and lungs upon exposure. Emissions from fossil fuel plants can release mercury into the air, where it can settle into the water supply and be exposed to human and aquatic life. The use of gold nanorods functionalized on solid substrates as a mercury sensor in tap water samples is investigated herein. The functionalization of the substrates involves the physical immobilization of the nanorods onto the solid...
Show moreMercury is a known environmental pollutant that can damage the brain, heart, kidney and lungs upon exposure. Emissions from fossil fuel plants can release mercury into the air, where it can settle into the water supply and be exposed to human and aquatic life. The use of gold nanorods functionalized on solid substrates as a mercury sensor in tap water samples is investigated herein. The functionalization of the substrates involves the physical immobilization of the nanorods onto the solid surface through the use of (3-mercaptopropyl)trimethoxysilane (MPTMS). The immobilization of the nanorods drastically increases their stability, allowing for use in complicated sample matrices. When gold nanorods are exposed to mercury in aqueous samples, their amalgamation to mercury metal causes a reduction of the effective aspect ratio of the nanoparticles and a blue shift of their maximum longitudinal surface plasmon resonance (SPR) absorption wavelength. Quantitative analysis is made possible due to the linear correlation that exists between the concentration of mercury and the wavelength shift of the maximum SPR absorption wavelength. In order to achieve the quantitative amalgamation of Hg (II) with the nanorods, it is necessary to reduce the mercury ions to mercury metal, which is accomplished herein via chemical or electrochemical processes. Chemical reduction of mercury was been carried out with a strong reducing agent, specifically sodium borohydride. Electrochemical reduction has been accomplished with gold nanorods immobilized on Indium Tin Oxide (ITO) substrates. Mercury determination in tap water using the immobilized gold nanorods was successfully conducted, with further experiments on improving selectivity with potential control, and improving sensitivity through flow injection analysis.
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Date Issued: 2019
Identifier: CFE0007544, ucf:52604
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007544

Title: Coated Quantum Dots: Engineering of Surface Chemistry for Biomedical and Agricultural Applications.
Creator: Maxwell, Tyler, Santra, Swadeshmukul, Gesquiere, Andre, Harper, James, Zou, Shengli, Leon, Lorraine, University of Central Florida
Abstract / Description: Quantum dots (QDs) are crystalline nanoparticles made from semiconductor material with sizes ranging from 1 to 10 nm in diameter. QDs are attractive fluorophores for bioimaging and sensing due to their size-dependent optical properties, broad absorption bands, high extinction coefficients and superior photostability. The combination of imaging and drug delivery in a single particle can provide valuable information and improve the efficacy of existing treatments. This dissertation highlights...
Show moreQuantum dots (QDs) are crystalline nanoparticles made from semiconductor material with sizes ranging from 1 to 10 nm in diameter. QDs are attractive fluorophores for bioimaging and sensing due to their size-dependent optical properties, broad absorption bands, high extinction coefficients and superior photostability. The combination of imaging and drug delivery in a single particle can provide valuable information and improve the efficacy of existing treatments. This dissertation highlights the use of QDs for biomedical and agricultural applications. Chapter 1 of this dissertation presents a background of QDs and outlines the synthesis methods of producing and functionalizing QDs. A discussion of the advantages and limitations of each method for producing water-soluble QDs and the rationale for the proposed research is also presented. Chapter 2 describes an activatable QD design for tracking of drug delivery for cancer treatment. QDs synthesized by microemulsion (ME) were cross-linked in a one-step procedure. Enhanced binding affinity of the probe to cell lines overexpressing folate receptors was shown through fluorescence microscopy. However, this system is not practical for the large-scale synthesis due to its complexity and can not be translated for clinical development. Chapter 3 presents a sol-gel synthesis method for producing water-soluble QDs utilizing the thiol-based small molecule capping agent as the stabilizer as an alternative to ME technique. This method was designed to be a simple (one-step), cost-effective, and scalable for making both manganese doped CdS and ZnS QDs. QDs were synthesized through sol-gel method with a library of organic thiol coatings and characterized by size, surface charge, stability, and optical properties. These particles were compared to QDs produced from ME synthesis and were found to have similar properties. Chapter 4 reports the sol-gel QDs as slow-release antibiotic delivery system for application as agricultural bactericide. Utilizing electrostatic interactions, the QDs were shown to be capable of improving the leaf adhesion and slowing the rate of release of streptomycin. Chapter 5 presents a summary of the major findings of this research and discusses the future research directions.
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Date Issued: 2019
Identifier: CFE0007681, ucf:52476
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007681

Title: The Schr(&)#246;dinger Equation with Coulomb Potential Admits no Exact Solutions.
Creator: Toli, Ilia, Zou, Shengli, Harper, James, Heider, Emily, Chen, Gang, Schulte, Alfons, University of Central Florida
Abstract / Description: We prove that the Schr(&)#246;dinger equation with the electrostatic potential energy expressed by the Coulomb potential does not admit exact solutions for three or more bodies. It follows that the exact solutions proposed by Fock are flawed. The Coulomb potential is the problem. Based on the classical (non-quantum) principle of superposition, the Coulomb potential of a system of many particles is assumed to be the sum of all the pairwise Coulomb potentials. We prove that this is not accurate...
Show moreWe prove that the Schr(&)#246;dinger equation with the electrostatic potential energy expressed by the Coulomb potential does not admit exact solutions for three or more bodies. It follows that the exact solutions proposed by Fock are flawed. The Coulomb potential is the problem. Based on the classical (non-quantum) principle of superposition, the Coulomb potential of a system of many particles is assumed to be the sum of all the pairwise Coulomb potentials. We prove that this is not accurate. The Coulomb potential being a hyperbolic (not linear) function, the superposition principle does not apply.The Schr(&)#246;dinger equation as studied in this PhD dissertation is a linear partial differential equation with variable coefficients. The only exception is the Schr(&)#246;dinger equation for the hydrogen atom, which is a linear ordinary differential equation with variable coefficients. No account is kept of the spin or the effects of the relativity.New electrostatic potentials are proposed for which the exact solutions of the Schr(&)#246;dinger equation exist. These new potentials obviate the need for the three-body force interpretations of the electrostatic potential.Novel methods for finding the exact solutions of the differential equations are proposed. Novel proof techniques are proposed for the nonexistence of the exact solutions of the differential equations, be they ordinary or partial, with constant or variable coefficients. Few novel applications of the established approximate methods of the quantum chemistry are reported. They are simple from the viewpoint of the quantum chemistry, but have some important aerospace engineering applications.
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Date Issued: 2019
Identifier: CFE0007733, ucf:52422
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007733

Title: A deoxyribozyme sensor and isothermal amplification for human sex determination.
Creator: Smith, Alexandra, Kolpashchikov, Dmitry, Campiglia, Andres, Harper, James, Beazley, Melanie, Tetard, Laurene, University of Central Florida
Abstract / Description: Ribozymes are known to catalyze biochemical reactions and behave like enzymes. They are naturally occurring and have very diverse functions within a cell. After investigating ribozymes that next step was to find if DNA can exhibit the same characteristics since RNA and DNA only differ by a ribose 2'-hydroxyl group. This evolution in curiosity gave rise to artificial DNA enzymes that can catalyze certain reactions and have been created by in vitro selection methods. Due to the ability to...
Show moreRibozymes are known to catalyze biochemical reactions and behave like enzymes. They are naturally occurring and have very diverse functions within a cell. After investigating ribozymes that next step was to find if DNA can exhibit the same characteristics since RNA and DNA only differ by a ribose 2'-hydroxyl group. This evolution in curiosity gave rise to artificial DNA enzymes that can catalyze certain reactions and have been created by in vitro selection methods. Due to the ability to manipulate and control DNA hybridization, the deoxyribozyme is advantageous to the field of molecular diagnostics. Other hybridization probes like Taqman for PCR (polymerase chain reaction) or a molecular beacon are more conventional methods for molecular diagnostics, but deoxyribozyme-based nucleic acid sensors are overall more sensitive due to their catalytic enhancement of a signal and more selective due to structural design. When the deoxyribozyme is split into two probes, it is very efficient in identifying a minute difference in sequence compared to the monolith structure. This binary deoxyribozyme sensor (BiDz) has two probes, each containing an analyte binding arm, substrate binding arm, and half of the catalytic core. The monolith structure, known as a catalytic molecular beacon (CMB), contains a hairpin that contains the analyte binding arm in the loop and the substrate binding arms in the stem. The catalytic core is fully intact but deemed inactive due to the substrate binding arms being complimentary to an inhibitory sequence forming the stem. Once the sensor binds the analyte, catalytic core is formed/activated and cleaves a substrate containing a fluorophore and quencher. When the substrate is cleaved a fluorescent signal is given off denoting the detection of the target DNA. Deoxyribozyme sensors can be applied to the field of human sex determination by detecting the Amelogenin gene. Found on both sex chromosomes, the Amelogenin gene is the most common marker used for sex determination because it exhibits dimorphism in length and sequence. Sex identification from ancient skeletal remains is crucial to understanding the social structure of our history. When conventional methods, such as metric analysis, are not an option due to the fragmented or prepubescent remains, molecular diagnostics are needed. Amplification of DNA is required to be able to detect the target sequence in human samples. Isothermal loop-mediated amplification (LAMP) is a fast and simple technique that provides ample amounts of amplicon. It is advantageous over PCR because it amplifies at one temperature and no thermal cycler is needed. Two different sensors have been designed to detect the X and Y specific sequences with high selectivity. From a direct comparison between the CMB and BiDZ, the binary structure has shown to be simpler and less expensive to design, and highly selective toward single base substitutions (SNS). While both sensors contain detection limits in the picomolar range, which is consistent with data published by other research groups, the CMB sensors failed to function at higher temperatures (55oC). BiDz sensors are shown to be superior to the CMB design, particularly when selectivity based analysis is desired. For human sex determination, the binary sensor detected sex specific sequences with great selectivity. The sensor then detected LAMP amplified DNA from male and female teeth after 30 minutes of amplification. Combining a binary deoxyribozyme sensor and isothermal amplification can provide a new and valuable method for human sex determination.
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Date Issued: 2017
Identifier: CFE0007133, ucf:52306
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007133

Title: Nitrogen-Containing Materials for Mechanochemical Synthesis, Luminescence Analysis, and Heterogeneous Catalysis.
Creator: Nash, David, Zhai, Lei, Hampton, Michael, Harper, James, Rex, Matthew, Blair, Richard, University of Central Florida
Abstract / Description: Various inorganic nitrogen-containing materials have been exploited for their different properties. Several nitride materials are commercially attractive due to their mechanical properties making them suitable for ceramic industries and wide bandgaps fitting for use as semiconductor and insulator materials, as well as optoelectronics. Nitride materials can exhibit versatility in applications such as the use of gallium nitride to make blue LEDs, nitrides of titanium and silicon being utilized...
Show moreVarious inorganic nitrogen-containing materials have been exploited for their different properties. Several nitride materials are commercially attractive due to their mechanical properties making them suitable for ceramic industries and wide bandgaps fitting for use as semiconductor and insulator materials, as well as optoelectronics. Nitride materials can exhibit versatility in applications such as the use of gallium nitride to make blue LEDs, nitrides of titanium and silicon being utilized as medical implants for their chemical inertness and hardness, and the heavy use of boron nitride as a solid lubricant in the cosmetic industry. Amines have been used as nitrogen-containing organic ligands in organometallic complexes that exhibit phenomenal photophysical properties. These complexes have been heavily studied for potential applications in optoelectronics and chemical sensing. This dissertation will focus on two nitrogen-containing materials that have yet to be explored for the potential applications to be discussed. The first is hexagonal-boron nitride (h-BN), which was previously mentioned to have a substantial use in the cosmetic industry, giving products such as lipstick, foundation, and blush their slick feeling. Computational models have shown the possibility of altered electronic properties of defect sites in the h-BN sheets. These defect sites will be explored experimentally to determine any catalytic activity. Specifically, the hydrogenation reaction using defect-laden hexagonal-boron nitride will be investigated. Successful catalysis would add to the short list of non-metal catalyst, and provide an alternative catalyst that costs significantly less than the traditional metal catalysts commonly used in commercial industries. The second of the two nitrogen-containing materials is a class of metal complexes based on organometallic clusters of copper(I) iodide. Copper(I) iodide clusters formed with amine ligands have been studied for around four decades and the photophysics behind their photoluminescent properties are well understood. Much of the work has been done for use as a potential emissive material in the optoelectronics field. They have also been studied for applications in the sensing of environmental compounds. Here, research will display its use as a novel sensor for narcotic substances. This forensic application will be further explored to develop and eventually commercialize a complete field drug testing system for law enforcement and crime lab use, with the goal to equip law enforcement personnel with a presumptive drug testing method that is accurate, easy-to-use, safe, adaptable, and affordable. This system will consist of a narcotic drug-indicating test strip, a handheld fluorescence spectrometer manufactured in-house using relatively inexpensive parts, and a mobile app that will leverage photoemission data of the tested drug samples collected by multiple crime labs to provide the ability for sample-to-reference data matching. Law enforcement users would have the ability to rapidly identify an unknown substance by applying it to a test strip, testing it using the spectrometer, and capturing an image of the resulting photoemission and analyzing the spectral profile in search of a match with the support of a cloud database.
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Date Issued: 2017
Identifier: CFE0007129, ucf:52297
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007129

Title: Advancements in Liquid Chromatography for the Determination of Polycyclic Aromatic Compounds in Environmental Samples.
Creator: Hayes, Hugh, Campiglia, Andres, Harper, James, Yestrebsky, Cherie, Frazer, Andrew, Coffey, Kevin, University of Central Florida
Abstract / Description: The purpose of this dissertation is to provide a new and improved analytical methodology for the analysis of polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic sulfur heterocycles (PASHs) in environmental samples. Hundreds of PAHs and PASHs are present in the environment and have great toxicological importance and the chemical determination of these components is a priority. The complete normal-phase liquid chromatography (NPLC) retention behavior has been explored for these...
Show moreThe purpose of this dissertation is to provide a new and improved analytical methodology for the analysis of polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic sulfur heterocycles (PASHs) in environmental samples. Hundreds of PAHs and PASHs are present in the environment and have great toxicological importance and the chemical determination of these components is a priority. The complete normal-phase liquid chromatography (NPLC) retention behavior has been explored for these compounds. Retention indices were determined for 124 PAHs, 62 methyl-PAHs (MePAHs), 67 PASHs, and 80 alkyl-PASHs on an aminopropyl (NH2) stationary phase which represents the most comprehensive study of polycyclic aromatic compounds in normal phase conditions to date. NPLC retention behavior for PAHs and PASHs directly correlated to the total number of aromatic carbons in the parent structures. The normal-phase retention behavior information was used to develop an NPLC fractionation procedure to aid in the sample cleanup for complex environmental matrices which can later be analyzed by gas chromatography/mass spectrometry (GC/MS). Standard Reference Material (SRM) 1597a (complex mixture of PAHs in coal tar), SRM 1991 (coal tar/petroleum extract), and SRM 1975 (diesel particulate extract) were analyzed before and after NPLC fractionation by using GC/MS. In SRM 1597a, the NPLC-GC/MS method allowed for the identification of 72 PAHs, 56 Me-PAHs, 35 PASHs, and 59 alkyl-PASHs. The NPLC-GC/MS procedure also provided the tentative identification of 74 PAHs and 117 MePAHs based on the molecular ion peak only. Furthermore, this method allowed for the following identification breakdown: SRM 1991(-)31 PASHs and 58 alkyl-PASHs; and SRM 1975(-)13 PASHs and 25 alkyl-PASHs.Additional work related to the NPLC fractionation of SRM 1597 included the collection of room-temperature fluorescence spectra for the 21 PAHs with molecular mass (MM) 302 Da known to be in SRM 1597a during reversed-phase liquid chromatography (RPLC) separation. Adding spectral features to a chromatographic run provided the tentative identification of 20 PAHs based on retention times and the presence of 18 were confirmed on the basis of spectral profiles. The advancements in liquid chromatography presented in this dissertation via NPLC fractionation along with RPLC stop-flow fluorescence spectra collection shows potential for becoming routine methodologies for PAC determination in complex environmental samples.
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Date Issued: 2018
Identifier: CFE0007190, ucf:52244
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007190

Title: Folate conjugated hyperbranched polyester nanoparticles for prostate tumor-targeted delivery of a cytotoxic peptide via prostate specific membrane antigen.
Creator: Flores-Fernandez, Orielyz, Perez Figueroa, J. Manuel, Campiglia, Andres, Yestrebsky, Cherie, Harper, James, Khaled, Annette, University of Central Florida
Abstract / Description: Prostate Cancer is the second most deadly cancer in men, after lung cancer. The need for new and effective therapeutics that can constrain prostate cancer progression are challenged by the lack of suitable delivery strategies that target prostate cancer tissue. To study CT20p as potential chemotherapeutic agent in the treatment of prostate cancer we proposed the use of targetable hyperbranched polyester (HBPE) based nanoparticles as delivery system. Folic acid was conjugated to the...
Show moreProstate Cancer is the second most deadly cancer in men, after lung cancer. The need for new and effective therapeutics that can constrain prostate cancer progression are challenged by the lack of suitable delivery strategies that target prostate cancer tissue. To study CT20p as potential chemotherapeutic agent in the treatment of prostate cancer we proposed the use of targetable hyperbranched polyester (HBPE) based nanoparticles as delivery system. Folic acid was conjugated to the nanocarrier to improve the selectivity of the nanoparticle towards specific cell surface targets in prostate cancer cell lines. Specifically we evaluated LNCaP that up-regulated the PSMA receptor. The synthesis of folate conjugated hyperbranched polyester nanoparticles was accomplished using an aliphatic and biodegradable hyperbranched polyester (HBPE). HBPE was prepared from commercially available diethyl malonate and 4-bromobutyl acetate. Our AB2 type monomer displays a three-bond connectivity that grows three-dimensionally under specific polymerization conditions. The product, HBPE, is a polymer with globular configuration that contains surface carboxylic acid groups and holds hydrophobic cavities. Carboxylated HBPE nanoparticles were synthesized via solvent diffusion method. A variety of hydrophobic cargos including: dyes (DiR and DiI) and the cytotoxic peptide CT20p were successfully encapsulated. DLS along with STEM imaging reveal nanoparticle preparations with ~100 nm size. Using water-soluble carbodiimide chemistry, surface modifications were accomplished. Available carboxylic acid groups were conjugated to aminated folic acid to yield folate functionalized nanoparticles.We explore the targeting capability of the Folate-HBPE nanoparticles and demonstrated that the cell internalization of Folate-HBPE into prostate cancer cell lines (LNCaP and PSMA (+) PC-3) was attained via a PSMA-mediated targeting mechanism. Furthermore, when CT20p was delivered to PSMA expressing PCa cells, detachment and death was observed; together with a reduction in the levels of ?1 integrin (CD29) expression, an integrin implicate in cell communication and cell adhesion. CT20p inhibits cell proliferation within 24 h and produce significant cell death after 48 h post treatment. The IC50 of CT20p was calculated at ~7 nM. Additionally, we investigated the capability of Folate-HBPE(CT20p) to perform as a therapeutic agent, in an in vivo setup, using a murine prostate tumor model. The Folate-PEG-HBPE NPs protected CT20p while in circulation and allowed effective uptake by PSMA-mediated targeting. Treatment with Folate-HBPE(CT20p) display localize tumor targeting and significant tumor growth inhibition in PSMA(+) PCa cell lines within days. Together these results suggest the potential of Folate-HBPE(CT20p) nanoparticles in the treatment of prostate cancer.
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Date Issued: 2015
Identifier: CFE0006216, ucf:51112
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006216

Title: Improvements on Instrumentation to Explore the Multidimensionality of Luminescence Spectroscopy.
Creator: Moore, Anthony, Campiglia, Andres, Chumbimuni Torres, Karin, Harper, James, Rex, Matthew, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: This dissertation presents experimental and instrumentation developments that take full advantage of the multidimensional nature of line narrowing spectroscopy at liquid nitrogen (77 K) and liquid helium (4.2 K) temperatures. The inconvenience of sample freezing procedures is eliminated with the aid of cryogenic fiber optic probes. Rapid collection of multidimensional data formats such as wavelength time matrices, excitation emission matrices, time-resolved excitation emission matrices and...
Show moreThis dissertation presents experimental and instrumentation developments that take full advantage of the multidimensional nature of line narrowing spectroscopy at liquid nitrogen (77 K) and liquid helium (4.2 K) temperatures. The inconvenience of sample freezing procedures is eliminated with the aid of cryogenic fiber optic probes. Rapid collection of multidimensional data formats such as wavelength time matrices, excitation emission matrices, time-resolved excitation emission matrices and time resolved excitation emission cubes is made possible with the combination of a pulsed tunable dye laser, a spectrograph and an intensifier-charged coupled device. These data formats provide unique opportunities for processing vibrational luminescence data with second order multivariate calibration algorithms. The use of cryogenic fiber optic probes is extended to commercial instrumentation. An attractive feature of spectrofluorimeters with excitation and emission monochromators is the possibility to record synchronous spectra. The advantages of this approach, which include narrowing of spectral bandwidth and simplification of emission spectra, were demonstrated with the direct analysis of highly toxic dibenzopyrene isomers. The same is true for the collection of steady-state fluorescence excitation-emission matrices. These approaches provide a general solution to unpredictable spectral interference, a ubiquitous problem for the analysis of organic pollutants in environmental samples of unknown composition. Since commercial spectrofluorimeters are readily available in most academic institutions, industrial settings and research institutes, the developments presented here should facilitate the widespread application of line-narrowing spectroscopic techniques to the direct determination, no chromatographic separation, of highly toxic compounds in complex environmental matrixes of unknown composition.
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Date Issued: 2015
Identifier: CFE0005847, ucf:50934
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005847

Title: In Actu Et In Silicio: Linear and Nonlinear Photophysical Characterization of a Novel Europium Complex, and Incorporating Computational Calculations in the Analysis of Novel Organic Compounds.
Creator: Woodward, Adam, Belfield, Kevin, Campiglia, Andres, Harper, James, Frazer, Andrew, Cheng, Zixi, University of Central Florida
Abstract / Description: Despite not being a tangible substance, light is becoming an increasingly valuable tool in numerous areas of science and technology: the use of laser excitation of a fluorescent probe can generate incredibly detailed images of cellular structures without the need for large amounts of dissection; new types of solar cells are being produced using organic dyes to harvest light; computer data can be stored by inducing a chemical change in a compound through irradiation with light. However, before...
Show moreDespite not being a tangible substance, light is becoming an increasingly valuable tool in numerous areas of science and technology: the use of laser excitation of a fluorescent probe can generate incredibly detailed images of cellular structures without the need for large amounts of dissection; new types of solar cells are being produced using organic dyes to harvest light; computer data can be stored by inducing a chemical change in a compound through irradiation with light. However, before any of these materials can be applied in such a way, their properties must first be analyzed for them to be deemed viable.The focus of this dissertation is the photophysical characterization, linear and nonlinear, of a several novel organic compounds, and a europium complex, as well as using quantum chemical calculation techniques to understand some of the phenomena that are witnessed and begin to develop predictive capability. The nonlinear characterization of compounds utilizes wavelengths outside of their linear absorption range, where a focused beam can achieve the same excitation as one at half the wavelength, though this effect has a quadratic dependence on power.The potential for nonlinear excitation, or two-photon absorption (2PA), is becoming of increasing interest and importance for organic chromophores. Exciting only a small volume of material at a focal point makes it possible to nondestructively image samples in 3-dimensions, record data in multiple layers, and fabricate intricate structures through photopolymerization reactions.Lanthanides such as europium are known to exhibit sharp emission bands when excited, typically through an antenna effect due to the low probability of achieving direct excitation. This emission is long-lived, and through gating systems can readily be separated from background noise and autofluorescence (often observed in biological samples) that have much shorter lifetimes. Thus, one of the foci of this dissertation is the photophysical investigation of a series of novel lanthanide complexes, with particular attention to a europium complex.
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Date Issued: 2014
Identifier: CFE0005908, ucf:50891
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005908

Title: Mechanochemical Synthesis of Fuels from Sustainable Sources Utilizing Solid Catalysts.
Creator: Todd, Jacob, Zhai, Lei, Blair, Richard, Hampton, Michael, Harper, James, Rahman, Talat, University of Central Florida
Abstract / Description: The transition to biofuels as a means of curbing the emissions of greenhouse gases has given rise to several questions such as what to use as the feedstock and how to cost effectively process them.(&)nbsp; The production of bio-derived chemicals presents challenges in synthesis and in use as a drop-in fuel replacement.(&)nbsp; Through the use of mechanochemistry reaction pathways can be utilized that allow the efficient production of biofuels and bioderived chemicals.(&)nbsp; To this end...
Show moreThe transition to biofuels as a means of curbing the emissions of greenhouse gases has given rise to several questions such as what to use as the feedstock and how to cost effectively process them.(&)nbsp; The production of bio-derived chemicals presents challenges in synthesis and in use as a drop-in fuel replacement.(&)nbsp; Through the use of mechanochemistry reaction pathways can be utilized that allow the efficient production of biofuels and bioderived chemicals.(&)nbsp; To this end mechanically driven esterification and transesterification reactions were studied.(&)nbsp; It was found that the acid base properties of solid catalysts was critical to efficient reactions.(&)nbsp; Further investigation into mechanocatalytic reaction resulted in a reaction scheme where glucose can be used as a feedstock for the production of propane from glucose through a retro aldol reaction followed by hydrodeoxygenation.(&)nbsp; The use of mechanochemistry facilitates the efficient synthesis of important energy molecules and allows new reaction pathways to be exploited.(&)nbsp; The efficient production of bio-derived chemicals will reduce our impact on the environment.(&)nbsp;(&)nbsp;
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Date Issued: 2017
Identifier: CFE0006809, ucf:51805
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006809

Title: Multidimensional Room-Temperature Fluorescence Microscopy for the Nondestructive Analysis of Forensic Trace Textile Fibers.
Creator: Mujumdar, Nirvani, Campiglia, Andres, Sigman, Michael, Harper, James, Rex, Matthew, Peale, Robert, University of Central Florida
Abstract / Description: The purpose of this dissertation is to advance nondestructive methodology for forensic fiber examination. Non-destructive techniques that can either discriminate between similar fibers or match a known to a questioned fiber (-) and still preserve the physical integrity of the fibers for further court examination - are highly valuable in forensic science. A challenging aspect of forensic fiber examinations involves the comparison of fibers colored with visually indistinguishable dyestuffs....
Show moreThe purpose of this dissertation is to advance nondestructive methodology for forensic fiber examination. Non-destructive techniques that can either discriminate between similar fibers or match a known to a questioned fiber (-) and still preserve the physical integrity of the fibers for further court examination - are highly valuable in forensic science. A challenging aspect of forensic fiber examinations involves the comparison of fibers colored with visually indistinguishable dyestuffs. This is not an uncommon situation, as there are numerous indistinguishable fibers pre-dyed with commercial dyes of virtually identical colors. Minimal chemical structural variations are actually encouraged by the dye patent process and commercial competition.The common denominator to forensic methodology is the fact that fiber analysis primarily focuses on the dyes used to color the fibers and do not investigate other potential discriminating components present in the fiber. This dissertation explores a different aspect of fiber analysis as it focuses on the total fluorescence emission of fibers. In addition to the contribution of the textile dye (or dyes) to the fluorescence spectrum of the fiber, we consider the contribution of intrinsic fluorescence impurities (-) i.e. impurities imbedded into the fibers during fabrication of garments - as a reproducible source of fiber comparison. Although fluorescence microscopy is used in forensic labs for single fiber examination, measurements are made with the aid of band-pass filters that provide very limited information on the spectral profiles of fibers. We take the non-destructive nature of fluorescence microscopy to a higher level of selectivity with the collection of room-temperature fluorescence excitation emission matrices (RTF-EEMs). The information contained in the EEMs was first used to select the best excitation wavelength for recording first order data, i.e. two-dimensional fluorescence spectra. Pairwise comparisons involved the following visually indistinguishable fibers: nylon 361 pre-dyed with acid yellow (AY) 17 and AY 23, acrylic 864 pre-dyed with basic green (BG) 1 and BG 4, acetate satin 105B pre-dyed with disperse blue (DB) 3 and DB 14, and polyester 777 pre-dyed with disperse red (DR) 1 and DR 19. With the exception of acrylic 864 fibers dyed with BG1 and BG4, the comparison of two-dimensional spectra via principal component analysis (PCA) provided accurate fiber identification for all the analyzed fibers. The same approach was later applied to the investigation of laundering effects on the comparison of textile fibers. The presence of brighteners and other detergent components adsorbed in the fibers provided spectral fingerprints that enhanced the fiber identification process.The full dimensionality of EEMs was then explored with the aid of parallel factor analysis (PARAFAC), a second order algorithm capable to determine the number of fluorescence components that contribute to an EEM along with their individual excitation and emission profiles. The application of PARAFAC was carried out unsupervised and supervised by linear discrimination analysis (LDA). The classification performances of PARAFAC and LDA-supervised PARAFAC were compared to the one obtained with supervised discriminant unfolded partial least squares (DU-PLS). The best discrimination was obtained with the supervised DU-PLS, which allowed the pairwise differentiation of the four pairs of investigated fibers.DU-PLS was then used to investigate weathering effects on the spectral features of cotton 400 pre-dyed with DB1, nylon 361 pre-dyed with AY17 and acrylic 864 pre-dyed with BG4. The investigated fibers were exposed to humid (Florida) and dry (Arizona) weathering conditions for three, six, nine and twelve months. In all cases, this algorithm was unable to differentiate non-exposed acrylic fibers from exposed acrylic fibers. DU-PLS was able to differentiate non-exposed cotton and nylon fibers from exposed fibers to Florida and Arizona weathering conditions. It was possible to determine the period of exposure to either Florida or Arizona conditions. It was also possible to discriminate between fibers exposed to Florida or Arizona weathering conditions for the same period of time. These results provide the foundation for future studies towards a non-destructive approach capable to provide information on the history of the fiber.
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Date Issued: 2016
Identifier: CFE0006838, ucf:51773
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006838

Title: Novel Photodynamic Cancer Therapy Agent and Biochemical Phosphate Sensor Based on Nanomaterials.
Creator: Fadhel, Alaa, Campiglia, Andres, Belfield, Kevin, Harper, James, Koculi, Eda, Bhattacharya, Aniket, University of Central Florida
Abstract / Description: Biochemical research and clinical studies have revolutionized the field of medicine in both diagnosis and therapy. Researchers in the field of biochemistry and biotechnology are using nanomaterials in different applications to develop devices and materials that offer benefits to both patients and the health care industry. These include biochemical sensors, enzyme encapsulation, biomarkers, and drug delivery improvements for the treatment of cancer. This dissertation focuses on investigating...
Show moreBiochemical research and clinical studies have revolutionized the field of medicine in both diagnosis and therapy. Researchers in the field of biochemistry and biotechnology are using nanomaterials in different applications to develop devices and materials that offer benefits to both patients and the health care industry. These include biochemical sensors, enzyme encapsulation, biomarkers, and drug delivery improvements for the treatment of cancer. This dissertation focuses on investigating two biochemical aspects using nanomaterials; namely therapy and clinical diagnosis.For therapy purposes, Silica nanoparticles were used as drug delivery system to develop a new photodynamic cancer therapy agent photo-acid generator (PAG) that selectively induces necrotic cell death of cancer cells. The developed PAG is oxygen-independent and - when excited at specific wavelengths - drops the pH within the lysosome of cancer cells to produce apoptosis/necrosis. It was specifically designed for in vivo applications and conjugated with synthesized, highly monodispersed silica nanoparticles (Si NPs) functionalized with amine groups via amid links (SiN-NH-PAG). Additional Features include high photo-acid quantum yield, high one-photon (1PA) and two-photon absorption (2PA) with low fluorescence quantum yield. In vivo, confocal microscope studies with HCT-116 (Human colorectal carcinoma) cancer cells showed that photodynamic processes in the presence of PAG were completed under one- photon absorption (1PA) conditions. In these experiments, cells were imaged at 1 min intervals for a total of 4 hours with the aid of Differential Interference Contrast (DIC). Among the photodynamic therapy agents tested via cytotoxicity experiments with the MTS assay, (SiN-NH- PAG) showed the best efficiency to induce cell death. The increased effectiveness of the new agent is probably due to the large number of PAG groups present on the surface of Si NPs.iiLysosome colocalization indicates that PAGs are mainly built in lysosomes. The increase of acidic content inside the lysosome was demonstrated with the aid of the LysoSensor Green probe. The drop in the intralysosomal pH was approximately 0.3 units. This is a desirable outcome as most cells underwent necrosis at pH ? 4.4. For clinical diagnosis purposes, a biochemical sensor was developed for the analysis of phosphate ions in urine samples. Abnormal levels of inorganic phosphate in human urine samples are related to the development of certain types of cancers affecting several organs of the human body, including breast, pancreas, lung and thyroid. The new biochemical sensor is based on the fluorescence energy transfer between a lanthanide luminescent probe [Tb-EDTA]-1 and gold nanoparticles (Au NPs) capped with a Cetyltrimethylammonium bromide (CTAB) micelle. With this approach, it was possible to selectively determine inorganic phosphate (Pi) in urine samples at the micro-molar concentration level. Urine samples collected from healthy, non-smoking individuals showed no interference from concomitants usually found in human urine samples. The simplicity of analysis provides an approach well-suited for (")real-time(") monitoring of phosphate ions. Analysis time is made possible within approximately 10 min per sample.
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Date Issued: 2016
Identifier: CFE0006528, ucf:51384
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006528

DFT (3)	+ -
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SSNMR (2)	+ -
benzo[a]pyrene (2)	+ -
biofuels (2)	+ -

chemistry (2)	+ -
fluorescence spectroscopy (2)	+ -
hydrogen peroxide (2)	+ -
1JCC (1)	+ -
5-methylmellein (1)	+ -
Analytical Chemistry (1)	+ -
CASTEP (1)	+ -
Carbon-13 Chemical Shift Tensors (1)	+ -
Cholera toxin (1)	+ -
Computational Chemistry (1)	+ -
Computational chemistry (1)	+ -
Continuous metal film (1)	+ -
Coupling mode (1)	+ -
Crystal Structure Refinement (1)	+ -
DFT calculations (1)	+ -
DNA (1)	+ -
Deoxyribozyme (1)	+ -
Discrete Dipole Approximation (1)	+ -
Electrochemical sensors (1)	+ -
Enhanced electric fields. (1)	+ -
FIREMAT (1)	+ -
Fab chaperone assisted RNA crystallography (1)	+ -
Fano Resonance (1)	+ -
Fluorescence (1)	+ -
Fock (1)	+ -

ETD Collection (31)	+ -
Honors Collection (1)	+ -

Harper, James (32)	+ -
University of Central Florida (32)	+ -
Campiglia, Andres (15)	+ -
Zou, Shengli (9)	+ -
Frazer, Andrew (7)	+ -

Rex, Matthew (6)	+ -
Zhai, Lei (5)	+ -
Belfield, Kevin (4)	+ -
Blair, Richard (4)	+ -
Heider, Emily (4)	+ -
Yestrebsky, Cherie (4)	+ -
Beazley, Melanie (3)	+ -
Chen, Gang (3)	+ -
Chumbimuni Torres, Karin (3)	+ -
Clausen, Christian (3)	+ -
Coffey, Kevin (3)	+ -
Hampton, Michael (3)	+ -
Kolpashchikov, Dmitry (3)	+ -
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