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Title: CONFORMATIONS OF TRICYANOFURAN-TYPE METASTABLE-STATE PHOTOACIDS.
Creator: Arias, Juan E, Chumbimuni-Torres, Karin Y., University of Central Florida
Abstract / Description: Tricyanofuran-type metastable-state photoacids, relative newcomers to the field of photochromism, outperform traditional light-controlled molecular switches in regards to applicability in biological systems. In a preliminary attempt to understand the underlying processes that govern these compounds, this thesis project establishes the isomeric identity of an unsubstituted tricyanofuran-type metastable-state photoacid, referred to as TCF 1 in this work. Two-dimensional nuclear magnetic...
Show moreTricyanofuran-type metastable-state photoacids, relative newcomers to the field of photochromism, outperform traditional light-controlled molecular switches in regards to applicability in biological systems. In a preliminary attempt to understand the underlying processes that govern these compounds, this thesis project establishes the isomeric identity of an unsubstituted tricyanofuran-type metastable-state photoacid, referred to as TCF 1 in this work. Two-dimensional nuclear magnetic resonance experiments are employed to experimentally determine the presence and identity of the open-form TCF 1 isomers. Electronic structure calculations are then used to provide quantitative insight into the experimental results. Experiment and theory show that four out of eight possible open-form isomers exist in solution. To validate the information obtained theoretically, the calculation methodologies are tested against experimental chemical shifts. The impressive agreement with the experiments gives credibility to the picture painted by the theoretical models.
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Date Issued: 2019
Identifier: CFH2000470, ucf:45707
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000470

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: Development and Characterization of Solid-Contact Paper-Based and Micro Ion-Selective Electrodes for Environmental Analysis.
Creator: Armas, Stephanie, Chumbimuni Torres, Karin, Beazley, Melanie, Santra, Swadeshmukul, University of Central Florida
Abstract / Description: Ion-selective electrodes (ISEs) have extensively been used for food analysis, as medical diagnostic tools, and for some environmental applications. However, ISEs are hindered by the need of a bulky reference electrode and the pre-conditioning step of the sensor, which can often be lengthy. This work will discuss how the direct addition of target analyte into the cocktail sensing membrane can circumvent the pre-conditioning step. Furthermore, the work is presented in an optimized ready-to-use...
Show moreIon-selective electrodes (ISEs) have extensively been used for food analysis, as medical diagnostic tools, and for some environmental applications. However, ISEs are hindered by the need of a bulky reference electrode and the pre-conditioning step of the sensor, which can often be lengthy. This work will discuss how the direct addition of target analyte into the cocktail sensing membrane can circumvent the pre-conditioning step. Furthermore, the work is presented in an optimized ready-to-use single strip design, where the bulky glass reference electrode (RE) is no longer needed. The bulky RE was replaced by drop casting a simple two-component mixture consisting of the co-polymer methyl methacrylate-co-decyl methacrylate and the ionic liquid 1-Ethyl-3-methylimidazolium bis (trifluoromethane sulfonyl) amide. Furthermore, this work will also highlight the benefits of solid-contact ISEs, specifically focusing on two solid- contact platforms: 1) paper-based and 2) a micro-electrode platform. Paper-based based sensors were designed to be used as a possible diagnostic tool to be implemented in undeveloped countries to monitor low levels of potassium and iodide, as model ions. The micro((&)#181;) ISEs were applied for the in-situ analysis of zinc in citrus plants as a mean to monitor and assess disease progression or therapy.
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Date Issued: 2018
Identifier: CFE0007152, ucf:52316
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007152

Title: Metastable-State Photoacids: Synthesis, Properties, and Applications.
Creator: Patel, Parth, Chumbimuni Torres, Karin, Hernandez, Florencio, Santra, Swadeshmukul, Beazley, Melanie, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: Reversible photochromic compounds have the ability to reversibly change its color when it absorbs photons of a particular wavelength. This process of color change is a consequence of structural changes within the compound, such as cis-trans photo-isomerization. Some examples of photochromic compounds are spiropyrans, spirooxazines, diarylethenes and azobenzenes. These compounds have been extensively studied for decades, and are used in various applications such as biomedicine, chemical...
Show moreReversible photochromic compounds have the ability to reversibly change its color when it absorbs photons of a particular wavelength. This process of color change is a consequence of structural changes within the compound, such as cis-trans photo-isomerization. Some examples of photochromic compounds are spiropyrans, spirooxazines, diarylethenes and azobenzenes. These compounds have been extensively studied for decades, and are used in various applications such as biomedicine, chemical sensors and harvesting solar energy. However, majority of photochromic compounds are initially activated by ultraviolet (UV) light. The use of UV light is harmful for biological applications and photo-degrade the compound over repeated use. To overcome these limitations, a new class of reversible photochromic compound was introduced, called metastable-state photoacid (mPAH). In brief, mPAH is a photochromic compound which can photo-dissociate its protons under visible light and can thermally re-capture the released protons efficiently in the dark. Based on this unique property, in this research, we (1) synthesized different mPAH, and (2) studied and characterized their physicochemical (acidity, kinetics, and optical) properties. Additionally, we (3) applied different visible light activated mPAHs towards light controllable polymeric-based ion-selective optodes for detection of calcium ions and sodium ions, and modulate fluorescence with pH. The research presented herein opens new avenues towards the synthesis of mPAH derivatives and could be applied to any proton-transfer process related applications which requires wireless controllability with high sensitivity.
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Date Issued: 2019
Identifier: CFE0007849, ucf:52769
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007849

Title: Polyelectrolyte complexes based on poly(acrylic acid): mechanics and applications.
Creator: Lu, Xiaoyan, Zhai, Lei, Zou, Shengli, Chumbimuni Torres, Karin, Kolpashchikov, Dmitry, Dong, Yajie, University of Central Florida
Abstract / Description: Poly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic conditionwhen the carboxylic group loses a proton. These carboxylate group can interact with polycationsand metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable propertiesand multifunctional nanoscale structures through chemical reactions. This research focuses onnanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferricion concentration on the...
Show morePoly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic conditionwhen the carboxylic group loses a proton. These carboxylate group can interact with polycationsand metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable propertiesand multifunctional nanoscale structures through chemical reactions. This research focuses onnanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferricion concentration on the mechanical properties of PAA-based single naonofiber by using dark fieldmicroscopy imaging and persistence length analysis. The application of PAA-based nanofibermats loaded with MnO2 for supercapacitors was also explored. As a free-standing and flexiblesupercapacitor electrode, the nanofiber mat exhibited outstanding properties including high specificcapacitance, excellent reversible redox reactions, and fast charge/discharge ability. Since PAA is abiocompatible polymer, PAA-based PEC was applied as a drug-carrier in a drug delivery system.In this project, core-shell nanoparticles were fabricated with chitosan as the core and PAA as theshell to incorporate with the drug gemcitabine. Several parameters were investigated to obtainthe optimal nanoparticle size. The as-prepared drug delivery system shows prolonged releasingprofile.
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Date Issued: 2018
Identifier: CFE0007045, ucf:52004
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007045

Title: A Universal Electrochemical Biosensor for the Detection of Nucleic Acids based on a Four-Way Junction Structure.
Creator: Mills, Dawn, Chumbimuni Torres, Karin, Kolpashchikov, Dmitry, Campiglia, Andres, Dupras, Tosha, Tetard, Laurene, University of Central Florida
Abstract / Description: Electrochemical hybridization sensors have been explored extensively for analysis of specific nucleic acids. However, commercialization of the platform is hindered by the need for attachment of separate oligonucleotide probes complementary to a RNA or DNA target to an electrode's surface. This dissertation demonstrates that a single probe can be used to analyze several nucleic acid targets of different lengths with high selectivity, low cost and can be regenerated in 30 seconds by a simple...
Show moreElectrochemical hybridization sensors have been explored extensively for analysis of specific nucleic acids. However, commercialization of the platform is hindered by the need for attachment of separate oligonucleotide probes complementary to a RNA or DNA target to an electrode's surface. This dissertation demonstrates that a single probe can be used to analyze several nucleic acid targets of different lengths with high selectivity, low cost and can be regenerated in 30 seconds by a simple water rinse. The universal electrochemical four-way junction (4J)-forming (UE4J) sensor consists of a universal DNA stem-loop (USL) probe attached to the electrode's surface and two adaptor strands (m and f) which hybridize to the USL probe and the analyte to form a 4J structure. The UE4J sensor enables a high selectivity by recognition of a single base substitution, even at room temperature. The sensor was monitored with voltammetry and electrochemical impedance spectroscopy using different redox labeling strategies and optimized using synthetic nucleic acid sequences. After the sensor was optimized and fully characterized, it was modified for the detection of the Zika virus. The UE4J sensor presented here opens a venue for a re-useable universal platform that can be adopted at low cost for the analysis of potentially any DNA or RNA targets.
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Date Issued: 2017
Identifier: CFE0007290, ucf:52146
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007290

Title: DEVELOPMENT AND APPLICATION OF MICROELECTRODES TO STUDY IN SITU DISINFECTANT LOSS AND CORROSION ON METAL SURFACE.
Creator: Ma, Xiangmeng, Lee, Woo Hyoung, Duranceau, Steven, Sadmani, A H M Anwar, Chumbimuni Torres, Karin, University of Central Florida
Abstract / Description: The primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing...
Show moreThe primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing to the brass in free chlorine solution, reflecting oxygen could be a major part of the corrosion initiation process. While cement showed less reactive characteristics to disinfectants and oxygen compared to the brass profiles, however, pH showed a significant rise for cement coupon under monochloramine condition. In galvanic experiment, the developed lead micro-ISE (100 (&)#181;m tip diameter) showed excellent performance toward soluble lead (Pb2+) with the sensitivity of 22.2 (&)#177; 0.5 mV decade-1 and limit of detection (LOD) of 1.22(&)#215;10-6 M (0.25 mg L-1). The response time was less than 10 seconds with a working pH range of 2.0 (-) 7.0. Using the lead micro-ISE, lead concentration microprofiles were measured from the bulk to the metal surface over time. Combined with two-dimensional (2D) pH map, this work clearly demonstrated that lead leaching at the metal surface is non-uniform and lower surface pH leads to higher lead leaching from the surface. Once significant pH variation (?pH: 6.0) was developed across brass-lead joint coupon, even a small pH change (?pH: 0.6) within the Pb/Sn alloy resulted in 4 times different surface lead concentrations (42.93 vs. 11.61 mg L-1) and 5 times different fluxes (18.5(&)#215;10-6 vs. 3.5(&)#215;10-6 mg cm-2 s-1). Continuous surface lead leaching monitoring and surface characterization found that free chlorine is the primary contributor to lead leaching.
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Date Issued: 2017
Identifier: CFE0007289, ucf:52165
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007289

Title: Forward Osmosis for Algae Dewatering and Electrical Field-driven Membrane Fouling Mitigation.
Creator: Munshi, Faris, Lee, Woo Hyoung, Duranceau, Steven, Sadmani, A H M Anwar, Chumbimuni Torres, Karin, University of Central Florida
Abstract / Description: Efficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was...
Show moreEfficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was achieved with a 29% flux drop. Among three different DSs, although NH4Cl was the best candidate for improved water flux and low reverse salt flux (RSF), it could accelerate cell division, reducing settleability during the FO process. However, RSF originated from NaCl could increase lipid content (~ 49%) in algal biomass probably due to the osmotic imbalance in algal cells. During FO operations, membrane fouling would be an inherent problem against sustainable algae dewatering. In this study, a novel approach was investigated by coupling the FO with an electric field for developing repulsion forces that can prolong the filtration cycle and mitigate foulant attachment. Several electric fields (0.33, 0.13 and 0.03 V mm-1) were applied in continuous and pulsing modes (10sec intervals) to mitigate membrane fouling for effective algae dewatering. The electric field FO configuration used in this study was able to produce 3.8, 2.2 and 2.2 times greater flux at the applied potential of -1.0, -0.4, and -0.1 V, respectively, compared to the control (without an electric field). A high potential of -10 V for 60 sec was applied as an optimal cleaning procedure with a high ability to recover flux (99%). The study also investigated the effect of the electric fields on bulk pH, conductivity, settling velocity, lipid content and microalgal morphology. Overall, this study demonstrates a novel technology for algae dewatering in FO application using the aquaporin-based PES membrane.
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Date Issued: 2019
Identifier: CFE0007507, ucf:52632
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007507

Title: Split Aptameric Turn-On Fluorescence Sensor for Detection of Sequence Specific Nucleic Acid.
Creator: Kikuchi, Nanami, Kolpashchikov, Dmitry, Zhai, Lei, Chumbimuni Torres, Karin, Chen, Gang, Teter, Kenneth, University of Central Florida
Abstract / Description: Nucleic acid amplification tests (NAATs) enable sensitive detection of low density infections that microscopy and rapid diagnostic test are not capable of detecting. They enable quantitative and qualitative nucleic acid detection, genotype analysis, and single nucleotide polymorphism (SNP) detection. Current state of the art molecular probes used with NAATs includes molecular beacon (MB), Taqman and its variations. This work presents novel molecular probe designed from Spinach and Dapoxyl...
Show moreNucleic acid amplification tests (NAATs) enable sensitive detection of low density infections that microscopy and rapid diagnostic test are not capable of detecting. They enable quantitative and qualitative nucleic acid detection, genotype analysis, and single nucleotide polymorphism (SNP) detection. Current state of the art molecular probes used with NAATs includes molecular beacon (MB), Taqman and its variations. This work presents novel molecular probe designed from Spinach and Dapoxyl aptamers. The aptamers are split into two parts (split aptamer), allowing greater sensitivity and selectivity towards fully complementary nucleic acid analyte. The major advantage of split aptamer probe over state-of-the-art fluorescent probes is its high selectivity: in the presence of a single base mismatched analyte, it produces only background fluorescence, even at room temperature. SSA is a promising tool for label-free analysis of nucleic acids at ambient temperatures.Split spinach aptamer (SSA) probes and split dapoxyl aptamer (SDA) for fluorescent analysis of nucleic acids were designed and tested. In both split aptamer design, two RNA or RNA/DNA or DNA strands hybridized to a specific nucleic acid analyte and formed a binding site for fluorescent dye, which was accompanied by up to 270-fold and 69-fold increase in fluorescence. SSAr consisted entirely of ribonucleotides which potentially be expressed in live cells and used for imaging of specific mRNAs. For in vitro RNA/DNA analysis, SDA consisting of entirely DNA are preferable due to greater chemical stability, lower synthetic cost and reduced ability to form intramolecular structures. Additionally, we designed two DNA strands that function as an adapter for SSA and demonstrated how a single universal spinach aptamer (USSA) probe can be used to detect multiple (potentially any) nucleic acid sequences. USSA can be used for cost-efficient and highly selective analysis of even folded DNA and RNA analytes, as well as for the readout of outputs of DNA logic circuits.
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Date Issued: 2018
Identifier: CFE0007031, ucf:51976
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007031

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: Solid Phase Extraction Room Temperature Fluorescence Spectroscopy for the Direct Quantification of Monohydroxy Metabolites of Polycyclic Aromatic Hydrocarbons in Urine Samples.
Creator: Calimag, Korina Jesusa, Campiglia, Andres, Belfield, Kevin, Yestrebsky, Cherie, Chumbimuni Torres, Karin, Schulte, Alfons, University of Central Florida
Abstract / Description: Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation pre-concentrates PAH, simplifies matrix composition, and...
Show morePolycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation pre-concentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) are the basis for standard PAH identification and determination. Ultraviolet (UV) absorption and room temperature fluorescence detection are both widely used in HPLC, but the specificity of these detectors is modest. Since PAH identifi(&)#172;cation is solely based on retention times, unambiguous PAH identification requires complete chromatographic resolution of sample components. When HPLC is applied to (")unfamiliar(") samples, the EPA recommends that a supporting analytical technique such as GC-MS be applied to verify compound identification and to check peak-purity HPLC fractions. Independent of the volume of extracted water, the approximate time required to separate and determine the sixteen (")priority pollutants(") (EPA-PAH) via HPLC is approximately 60min. If additional GC-MS analysis is required for unambiguous PAH determination, the total analysis time will reach 2-3 hours per sample. If the concentrations of target species are found to lie outside the detector's response range, the sample must be diluted and the process repeated. These are important considerations when routine analysis of numerous samples is contemplated. Parent PAH are relatively inert and need metabolic activation to express their carcinogenicity. By virtue of the rich heterogeneous distribution of metabolic products they produce, PAH provide a full spectrum of the complexity associated with understanding the initial phase of carcinogenesis. PAH metabolites include a variety of products such as expoxides, hydroxyl aromatics, quinines, dihydrodiols, dioepoxides, tetrols and water soluble conjugates. During the past decades tremendous efforts have been made to develop bio-analytical techniques that possess the selectivity and sensitivity for the problem at hand. Depending on the complexity of the sample and the relative concentrations of the targeted metabolites, a combination of sample preparation techniques is often necessary to reach the limits of detection of the instrumental method of analysis. The numerous preparation steps open ample opportunity to metabolite loss and collection of inaccurate data. Separation of metabolites has been accomplished via HPLC, capillary electrophoresis (CE) and GC-MS. Unfortunately, the existence of chemically related metabolic products with virtually identical fragmentation patterns often challenges the specificity of these techniques. This dissertation presents significant improvements in various fronts. Its first original component (-) which we have named solid-phase nano-extraction (SPNE) - deals with the use of gold nanoparticles (Au NPs) as extracting material for PAH. The advantages of SPNE are demonstrated for the analysis of PAH in water samples via both HPLC1 and Laser-Excited Time-Resolved Shpol'skii Spectroscopy (LETRSS).2 The same concept is then extended to the analysis of monohydroxy-PAH in urine samples via SPE- HPLC3 and In-Capillary SPNE-CE.4 The second original component of this dissertation describes the application of Shpol'skii Spectroscopy to the analysis of polar PAH metabolites. The outstanding selectivity and sensitivity for the direct analysis of PAH at trace concentration levels has made Shpol'skii spectroscopy a leading technique in environmental analysis.5 Unfortunately, the requirement of a specific guest-host combination - typically a non-polar PAH dissolved in an n-alkane - has hindered its widespread application to the field of analytical chemistry. This dissertation takes the first steps in removing this limitation demonstrating its feasibility for the analysis of polar benzo[a]pyrene metabolites in alcohol matrixes.
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Date Issued: 2013
Identifier: CFE0005141, ucf:50693
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005141

Title: Degradation of Hexachlorobenzene, Pentachlorophenol and Pentachloroanisole using Activated Magnesium in an Acidified Ethanol/Ethyl Lactate Cosolvent System.
Creator: Garbou, Amel, Yestrebsky, Cherie, Clausen, Christian, Zou, Shengli, Chumbimuni Torres, Karin, Randall, Andrew, University of Central Florida
Abstract / Description: For many centuries, chemists have dedicated many labor-intensive hours to improving the quality of life for mankind by developing synthetic methods for the production of compounds which fulfill the needs and meet the demands of society. However, the innovation of such compounds has frequently come at the cost of detrimental side-effects that do not always present themselves until many years, or even decades, following their initial application. Many compounds in this category come in the form...
Show moreFor many centuries, chemists have dedicated many labor-intensive hours to improving the quality of life for mankind by developing synthetic methods for the production of compounds which fulfill the needs and meet the demands of society. However, the innovation of such compounds has frequently come at the cost of detrimental side-effects that do not always present themselves until many years, or even decades, following their initial application. Many compounds in this category come in the form of globally-distributed halogenated molecules which are toxic to many living organisms, susceptible to bioaccumulation and resistant to biodegradation processes. Such compounds are classified as persistent organic pollutants (POPs), and require safe, sustainable and economically viable remediation techniques due to their destructive effects on organisms and the environment In the work done for this dissertation study, three particular POPs, which can be further classified as Polychlorinated Aromatic Hydrocarbons (PCAHs), were studied: pentachlorophenol (PCP), hexachlorobenzene (HCB) and pentachloroanisole (PCA).Chlorophenols are highly toxic compounds, usually found in soils, water, and effluents resulting from industrial activities. These environmentally-persistent compounds have been found to exhibit probable carcinogenic properties by the United States Environmental Protection Agency and the International Agency for Research on Cancer. The most toxic chlorophenol is PCP, which has a regulated maximum contaminant level (MCL) of 0.03 mg/L in water. Due to the high toxicity of PCP, it is necessary to treat water and soils that have tested positive for concentrations above the MCL. The aim of this work is to demonstrate the capabilities of using ball-milled zero-valent magnesium powder with various amendments, such as acetic acid (as an activator) and ethanol for the dechlorination of PCP. The dechlorination processes of these various combinations wereivcompared in an attempt to determine the most effective system for the degradation of PCP to phenol. Three systems with powerful capabilities of treatment were studied: ball-milled magnesium powder, ball-milled magnesium carbon (Mg/C), and mechanically alloyed magnesium with palladium. The results of these studies indicate that the most rapid and complete PCP dechlorination is achieved using mechanically alloyed Mg/Pd and a matrix consisting of at least 0.02 g Mg0/mL of ethanol and 10 ?L acetic acid/mL of ethanol, in which case 20 ng/?L of PCP was dechlorinated to phenol in approximately 15 min. with a carbon mass balance of 94.89%. Hexachlorobenzene (HCB), like many chlorinated organic compounds, has accumulated in the environment from agricultural and industrial activity. After its introduction as a fungicide in 1945, the extensive use of this toxic chemical has instigated its infiltration into all food types. Prohibition from commercial use was enforced in the United States in 1966 due to animal, and possible human, carcinogenic effects. Because of the health risks and the adverse impact on various ecosystems, remediation of this contaminant is of vital concern. The objective of this study is to evaluate the proficiency of activated-magnesium metal in a protic solvent system to enhance the reductive dechlorination of HCB. Experimental results were compared with those predicted by quantum chemical calculations based on Density Functional Theory (DFT). Multivariate analysis detected complete degradation of HCB within 30 minutes, having a rate constant of 0.222 min-1, at room temperature. Dechlorination was hypothesized to proceed via an ionic mechanism, and the main dechlorination pathways of HCB in 1:1 ethanol/ethyl lactate were HCB ? PCBz ? 1,2,4,5-TCB; 1,3,4,5-TCB ? 1,2,4-TriCB; 1,3,5-TriCB ? 1,4-DiCB; 1,3-DiCB. The direct relationship between the decreasing number of Cl substituents and dechlorination reaction kinetics agrees with the ?G values predicted by the computational model. Therefore, the lowest energy pathway for C-vCl bond dissociation predicted computationally agrees with the experimentally determined kinetic data. The experimental results from these studies have helped to improve our understanding of the dechlorination mechanisms, thereby offering insight into the most efficient pathways for remediation in the environment. This methodology shows promise for the development of an economic and sustainable field application for the treatment of other chlorinated aromatic compounds. In further work, developments will be made in the modification of the system to allow for the implemetation of field-scale applications.Chloroanisoles are compounds that have similar properties to chlorophenols, but have a higher tendency to bioaccumulate and resist degradation because of their lipophilicity. They are not manufactured for commercial use, but exist in equilibrium with chlorophenols in the environment through biological transformation. Due to the toxicity of both compounds, a strategy for remediation is highly sought after. This study has served to develop an approach to meet the needs for this treatment, based on the successful treatment of PCPs using zero-valent magnesium (ZVMg) discussed in Chapter 1. The results of the method, which makes use of ZVMg/C in acidified ethanol, are compared for both target analytes. Both substrates were degraded to less-chlorinated byproducts within the first four hours; however PCP vanished at a faster rate with no detection at seven minutes. The more heavily-chlorinated byproducts showed faster degradation rates for both compounds, which also had 2,4-dichlorinated congeners in common as major byproducts. The mole balances of PCA and PCP were 92.6% and 94.8%, respectively. Further studies were done to enhance degradation kinetics by re-spiking with acetic acid after two weeks. Although complete degradation was still not achieved, a slight improvement was observed for bothvicompounds, more so with respect to PCP. Kinetic data followed pseudo first-order trends for the degradation of both PCA and PCP.
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Date Issued: 2016
Identifier: CFE0006456, ucf:51433
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006456

Title: Theoretical-Experimental Study of the Two-Photon Circular Dichroism of Helicenes and Aromatic Amino Acids in the UV Region: From the Structure-Property Relationship to the Final Implementation.
Creator: Vesga Prada, Yuly Katherine, Hernandez, Florencio, Huo, Qun, Chumbimuni Torres, Karin, Zou, Shengli, Tatulian, Suren, University of Central Florida
Abstract / Description: Two-photon circular dichroism (TPCD) has been recognized for its exceptional spectroscopic ability for the structural and conformational analysis of chiral systems due to its high sensitivity to small peptide structural distortions. In 2008, Hernandez and co-workers demonstrated TPCD experimentally by the development of the Double L-scan technique. Since then, we have been working on a systematic theoretical-experimental study of chiral molecules using TPCD. In this dissertation, I present my...
Show moreTwo-photon circular dichroism (TPCD) has been recognized for its exceptional spectroscopic ability for the structural and conformational analysis of chiral systems due to its high sensitivity to small peptide structural distortions. In 2008, Hernandez and co-workers demonstrated TPCD experimentally by the development of the Double L-scan technique. Since then, we have been working on a systematic theoretical-experimental study of chiral molecules using TPCD. In this dissertation, I present my contribution to the continuation to the study of the structure-property relationship of TPCD in molecules with axial chirality in solution, as well as the implementation of the TPCD measurements in the near- and far-UV regions. Employing a theoretical-experimental approach I will discuss: 1) the effect of the pulse width of the excitation source on the TPCD spectra of biaryl derivatives, 2) the theoretical study of the TPCD signal in the far-UV on molecular structures simulating aromatic amino acid residues in proteins with secondary structures, and 3) the pros and cons of the implementation of the FUV-TPCD spectrometer. The outcomes of my research reveal the potential of TPCD for the conformational analysis of relatively complex molecular systems such as peptides in the far-UV region, an area never accessed before. Additionally, we exposed the applicability of TPCD as a complimentary method to standard electronic circular dichroism (ECD) for the study of complex structures. Finally, I demonstrate for the very first time experimental evidence of TPCD in the near- to Far-UV region.
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Date Issued: 2016
Identifier: CFE0006514, ucf:51375
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006514

Title: Synthesis of Fluorene-based derivatives, Characterization of Optical properties and their Applications in Two-photon Fluorescence Imaging and Photocatalysis.
Creator: Githaiga, Grace, Belfield, Kevin, Patino Marin, Pedro, Chumbimuni Torres, Karin, Zou, Shengli, Cheng, Zixi, University of Central Florida
Abstract / Description: The two-photon absorption (2PA) phenomenon has attracted attention from various fields ranging from chemistry and biology to optics and engineering. Two of the common NLO applications in which organic materials have been used are three-dimensional (3D) fluorescence imaging and optical power limiting. Two-photon absorbing materials are, therefore, in great demand to meet the needs of emerging technologies. Organic molecules show great promise to meet this need as they can be customized through...
Show moreThe two-photon absorption (2PA) phenomenon has attracted attention from various fields ranging from chemistry and biology to optics and engineering. Two of the common NLO applications in which organic materials have been used are three-dimensional (3D) fluorescence imaging and optical power limiting. Two-photon absorbing materials are, therefore, in great demand to meet the needs of emerging technologies. Organic molecules show great promise to meet this need as they can be customized through molecular engineering, and as the development of two-photon materials that suit practical application intensifies, so does research to meet this need. However, there remains some uncertainty in the particulars of design criteria for molecules with large 2PA cross sections at desired wavelengths, as such research to understand structure-property relationships is matter of significant importance. As a result, the full potential of 2PA materials has not been fully exploited. Several strategies to enhance the magnitude and tune the wavelength of 2PA have been reported for ?-conjugated organic molecules. On this account, we have designed novel fluorophores using the fluorene moiety and modified it to tune the properties of the compounds.Chapter 2 of this dissertation reports the successful application of fluorene-based compounds in photocatalysis; a process that involves the decomposition of organic compounds into environmentally friendly carbon dioxide and water attesting to the photostability of the fluorene moiety. A facile organic nanoparticle preparation method is reported in chapter 3 using the reprecipitation method, whose surface was then modified using a naturally occurring surfactant, Lecithin, and were then successfully used in fluorescence cell imaging. Chapter 4 reports the design and synthesis of a fluorene-based compound using an acceptor, s-indacene-1, 3, 5, 7(2H, 6H)-tetra one, or Janus Dione, a moiety that is relatively new and that has not been fully exploited despite its very attractive features. Owing to the hydrophobicity of this compound, notwithstanding its unprecedented 2PA cross section, it was not applicable in fluorescence cell imaging but provided the tenets for the design of related derivative. This limitation was circumvented in the concluding chapter by tuning the compound's hydrophilicity. The hydrophilic Janus dione probe was then used as envisioned for cell imaging as the dual prerequisites for fluorescence imaging probes; large 2PA cross sections and high fluorescence quantum yields were met.
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Date Issued: 2015
Identifier: CFE0005620, ucf:50207
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005620

Title: Forensic Application of Chemometric Analysis to Visible Absorption Spectra Collected from Dyed Textile Fibers.
Creator: Flores, Alejandra, Sigman, Michael, Yestrebsky, Cherie, Campiglia, Andres, Chumbimuni Torres, Karin, Ni, Liqiang, University of Central Florida
Abstract / Description: Forensic analysis of evidence consists of the comparison of physical, spectroscopic, or chemical characteristics of a questioned sample to a set of knowns. Currently, decisions as to whether or not the questioned sample can be associated or grouped with the knowns are left up to the discretion of the forensic analyst. The implications of these outcomes are presented as evidence to a jury in a court of law to determine if a defendant is guilty of committing a crime or not. Leading up to, and...
Show moreForensic analysis of evidence consists of the comparison of physical, spectroscopic, or chemical characteristics of a questioned sample to a set of knowns. Currently, decisions as to whether or not the questioned sample can be associated or grouped with the knowns are left up to the discretion of the forensic analyst. The implications of these outcomes are presented as evidence to a jury in a court of law to determine if a defendant is guilty of committing a crime or not. Leading up to, and since, the publication of the National Academy of Sciences (NAS) report entitled (")Strengthening Forensic Science in the United States: A Path Forward,(") the inadequacies of allowing potentially biased forensic opinion to carry such weight in the courtroom have been unmasked. This report exposed numerous shortcomings in many areas of forensic science, but also made recommendations on how to fortify the discipline. The main suggestions directed towards disciplines that analyze trace evidence include developing error rates for commonly employed practices and evaluating method reliability and validity.This research focuses on developing a statistical method of analysis for comparing visible absorption profiles collected from highly similarly colored textile fibers via microspectrophotometry (MSP). Several chemometric techniques were applied to spectral data and utilized to help discriminate fibers beyond the point where traditional methods of microscopical examination may fail. Because a dye's chemical structure dictates the shape of the absorption profile, two fibers dyed with chemically similar dyes can be very difficult to distinguish from one another using traditional fiber examination techniques. The application of chemometrics to multivariate spectral data may help elicit latent characteristics that may aid in fiber discrimination.The three sample sets analyzed include dyed fabric swatches (three pairs of fabrics were dyed with chemically similar dye pairs), commercially available blue yarns (100% acrylic), and denims fabrics (100% cotton). Custom dyed swatches were each dyed uniformly with a single dye whereas the dye formulation for both the yarns and denims is unknown. As a point for study, spectral comparisons were performed according to the guidelines published by the Standard Working Group for Materials Analysis (SWGMAT) Fiber Subgroup based on visual analysis only. In the next set of tests, principal components analysis (PCA) was utilized to reduce the dimensionality of the large multivariate data sets and to visualize the natural groupings of samples. Comparisons were performed using the resulting PCA scores where group membership of the questioned object was evaluated against the known objects using the score value as the distance metric. Score value is calculated using the score and orthogonal distances, the respective cutoff values based on a quantile percentage, and an optimization parameter, ?. Lastly, likelihood ratios (LR) were generated from density functions modelled from similarity values assessing comparisons between sample population data. R code was written in-house to execute all method of fiber comparisons described here. The SWGMAT method performed with 62.7% accuracy, the optimal accuracy rate for the score value method was 75.9%, and the accuracy rates for swatch-yarn and denim comparisons, respectively, are 97.7% and 67.1% when the LR method was applied.
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Date Issued: 2015
Identifier: CFE0005613, ucf:50212
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005613

Title: Advanced Nanoscale Characterization of Plants and Plant-derived Materials for Sustainable Agriculture and Renewable Energy.
Creator: Soliman, Mikhael, Tetard, Laurene, Vaidyanathan, Raj, Kang, Hyeran, Santra, Swadeshmukul, Zhai, Lei, Chumbimuni Torres, Karin, University of Central Florida
Abstract / Description: The need for nanoscale, non-invasive functional characterization has become more significant with advances in nano-biotechnology and related fields. Exploring the ultrastructure of plant cell walls and plant-derived materials is necessary to access a more profound understanding of the molecular interactions in the systems, in view of a rational design for sustainable applications. This, in turn, relates to the pressing requirements for food, energy and water sustainability experienced...
Show moreThe need for nanoscale, non-invasive functional characterization has become more significant with advances in nano-biotechnology and related fields. Exploring the ultrastructure of plant cell walls and plant-derived materials is necessary to access a more profound understanding of the molecular interactions in the systems, in view of a rational design for sustainable applications. This, in turn, relates to the pressing requirements for food, energy and water sustainability experienced worldwide.Here we will present our advanced characterization approach to study the effects of external stresses on plants, and resulting opportunities for biomass valorization with an impact on the food-energy-water nexus.First, the adaption of plants to the pressure imposed by gravity in poplar reaction wood will be discussed. We will show that a multiscale characterization approach is necessary to reach a better understanding of the chemical and physical properties of cell walls across a transverse section of poplar stem. Our Raman spectroscopy and statistical analysis reveals intricate variations in the cellulose and lignin properties. Further, we will present evidence that advanced atomic force microscopy can reveal nanoscale variations within the individual cell wall layers, not attainable with common analytical tools. Next, chemical stresses, in particular the effect of Zinc-based pesticides on citrus plants, will be considered. We will show how multiscale characterization can support the development of new disease management methods for systemic bacterial diseases, such as citrus greening, of great importance for sustainable agriculture. In particular, we will focus on the study of new formulations, their uptake and translocation in the plants following different application methods. Lastly, we will consider how plant reactions to mechanical and chemical stresses can be controlled to engineer biomass for valorization applications. We will present our characterization of two examples: the production of carbon films derived from woody lignocellulosic biomass and the development of nanoscale growth promoters for food crop. A perspective of the work and discussion of the broader impact will conclude the presentation.
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Date Issued: 2018
Identifier: CFE0007415, ucf:52717
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007415

Title: Multifunctional and Responsive Polyelectrolyte Nanostructures.
Creator: Malhotra, Astha, Zhai, Lei, Kolpashchikov, Dmitry, Ye, Jingdong, Chumbimuni Torres, Karin, Santra, Swadeshmukul, Fang, Jiyu, University of Central Florida
Abstract / Description: A polyelectrolyte complex is formed by mixing two oppositely charged polyelectrolytes in a solution. The electrostatic interactions between partially charged polymeric chains lead to the formation of a stable complex while avoiding the use of covalent cross linkers. Since complex formation can improve the stability of polyelectrolyte and metal ions in polyelectrolyte can provide various functionalities, PECs incorporated with metal ions are promising candidates for manufacturing stable and...
Show moreA polyelectrolyte complex is formed by mixing two oppositely charged polyelectrolytes in a solution. The electrostatic interactions between partially charged polymeric chains lead to the formation of a stable complex while avoiding the use of covalent cross linkers. Since complex formation can improve the stability of polyelectrolyte and metal ions in polyelectrolyte can provide various functionalities, PECs incorporated with metal ions are promising candidates for manufacturing stable and multifunctional structures. While the coordination of metal ions and polyelectrolytes has been extensively investigated in solutions and multilayer films, to our knowledge, no research has been performed to study the effect of metal ion/polyelectrolyte interactions on PECs structures and properties. The following research demonstrates the impact of different metal ions in controlling PEC structure morphology and applications. These discoveries indicate great potential of metal ions in PECs to fabricate functional PEC nanostructures.The research investigates the effect of the interactions between different metal ions and polyelectrolytes on the morphology and properties of PECs, explore the fabrication of different structures using embedded metal ions and understand the impact of metal ion/polyelectrolyte interactions on the nanoparticle structures. The research concludes: 1) incorporating metal ions of different valence into PECs introduces metal ion/polyelectrolyte interactions that can tune the morphology of PECs; 2) metal ion/polyelectrolyte interactions can be used to control the PECs swelling properties and stability in aqueous solutions; 3) the release of embedded metal ions from PECs to aqueous solutions is affected by metal ion/polyelectrolyte interactions; and 4) the embedded metal ions function as a reagent reservoir for various applications to produce functional structures. ?
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Date Issued: 2014
Identifier: CFE0005833, ucf:50918
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005833

Title: Monitoring Crystal Structure Refinements Using Solid-State NMR Chemical Shift Tensors.
Creator: Kalakewich, Keyton, Harper, James, Campiglia, Andres, Elsheimer, Seth, Chumbimuni Torres, Karin, Masunov, Artem, Moore, Sean, University of Central Florida
Abstract / Description: Inclusion of lattice-fields in density functional theory (DFT) methods has enabled the accurate calculation of solid-state nuclear magnetic resonance (SSNMR) chemical shift tensors. Calculated 13C and 15N tensors (i.e. 3 principle values per nucleus) can be used to monitor crystal structure refinements and to select the correct structure from a large population of computationally generated candidates. In this dissertation, chapter 2 describes a methodology to improve established crystal...
Show moreInclusion of lattice-fields in density functional theory (DFT) methods has enabled the accurate calculation of solid-state nuclear magnetic resonance (SSNMR) chemical shift tensors. Calculated 13C and 15N tensors (i.e. 3 principle values per nucleus) can be used to monitor crystal structure refinements and to select the correct structure from a large population of computationally generated candidates. In this dissertation, chapter 2 describes a methodology to improve established crystal structures from three different diffraction techniques involving geometric refinement monitored using SSNMR tensor values. The calculated 13C tensors for three relatively simple organic compounds (i.e. acetaminophen, naphthalene, and adenosine) are shown to markedly improve upon DFT refinement. The so-called GGA-PBE functional provided the best agreement with experimental data. The use of the three principle values of the tensor is required for such results as the average (i.e. the isotropic) is less accurate. Chapter 3 applies this method to differentiate between hundreds of computationally predicted crystal structures. Typically, lattice energy of each candidate is used to select the correct structure, a process which is seldom successful. Herein, it is demonstrated that when 13C tensors from DFT refined structures are used for structural ranking by comparison to experimental data, only the correct structure agrees with experimental data in all cases. Chapter 4 illustrates the use of 15N tensors to monitor DFT refinement as an alternative to the 13C approach of Chapter 2. 15N tensors have been very difficult to obtain previously, thus a novel experimental method is developed here which improves signal-to-noise by as much as 300% and allows routine measurement. This improvement also improves the accuracy of the tensor values. Overall, the 15N tensors are found to be at least 5 times more sensitive to DFT refinements than 13C values.
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Date Issued: 2017
Identifier: CFE0006888, ucf:51726
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006888

Chemometrics (2)	+ -
nucleic acids (2)	+ -
Algae (1)	+ -
Atomic Force Microscopy (1)	+ -
Binary Aptamer (1)	+ -

CASTEP (1)	+ -
Carbon-13 Chemical Shift Tensors (1)	+ -
Confocal Raman Microscopy (1)	+ -
Corrosion (1)	+ -
Crystal Structure Refinement (1)	+ -
DNA (1)	+ -
Drinking water (1)	+ -
Drug delivery (1)	+ -
Electric Field (1)	+ -
Electron Microscopy (1)	+ -
Energy storage (1)	+ -
Fluorescence Imaging (1)	+ -
Fluorescence Sensor (1)	+ -
Fluorescence Spectroscopy (1)	+ -
Forensics (1)	+ -
Forward Osmosis (1)	+ -
Fouling control (1)	+ -
GIPAW (1)	+ -
Galvanic corrosion (1)	+ -
Gas chromatogram-mass spectrometry (1)	+ -
Hexachlorobenzene (1)	+ -
Hybridization Probe (1)	+ -
Janus dione (1)	+ -
Materials Characterization (1)	+ -
Mechanics (1)	+ -

ETD Collection (17)	+ -
Honors Collection (1)	+ -

University of Central Florida (18)	+ -
Chumbimuni Torres, Karin (17)	+ -
Campiglia, Andres (5)	+ -
Kolpashchikov, Dmitry (5)	+ -
Lee, Woo Hyoung (4)	+ -

Santra, Swadeshmukul (4)	+ -
Zhai, Lei (4)	+ -
Zou, Shengli (4)	+ -
Harper, James (3)	+ -
Yestrebsky, Cherie (3)	+ -
Beazley, Melanie (2)	+ -
Belfield, Kevin (2)	+ -
Duranceau, Steven (2)	+ -
Hernandez, Florencio (2)	+ -
Sadmani, A H M Anwar (2)	+ -
Tetard, Laurene (2)	+ -
Arias, Juan E (1)	+ -
Armas, Stephanie (1)	+ -
Calimag, Korina Jesusa (1)	+ -
Chen, Gang (1)	+ -
Cheng, Zixi (1)	+ -
Chumbimuni-Torres, Karin Y. (1)	+ -
Clausen, Christian (1)	+ -
Dong, Yajie (1)	+ -
Dupras, Tosha (1)	+ -
Elsheimer, Seth (1)	+ -
Fang, Jiyu (1)	+ -
Flores, Alejandra (1)	+ -
Garbou, Amel (1)	+ -
Githaiga, Grace (1)	+ -

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