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- 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.
Show less - Date Issued
- 2017
- Identifier
- CFE0007129, ucf:52297
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007129
- Title
- URINALYSIS SCREENING OF DRUGS IN ADULTERATED SAMPLES VIA DIRECT ANALYSIS IN REAL TIME -- HIGH RESOLUTION/ MASS SPECTROMETRY (DART-HR/MS).
- Creator
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Olivieri, Bianca E, Bridge, Candice, University of Central Florida
- Abstract / Description
-
Current screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace....
Show moreCurrent screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace. Therefore, a majority of individuals add commonly known products into the sample to evade detection by developing a false negative result. Although specimen integrity examinations are performed to identify tampering of the sample, these results are typically biased on the experience of the examiner. The purpose of this study was to develop an analytical screening technique that will detect the drug of interest as well as the presence of any additional products that may be added into the sample via Direct Analysis in Real Time � High Resolution/Mass Spectrometry (DART-HR/MS) which is an ambient ionization source that produces fast mass spectrum results that can provide semi-quantitative information of the target metabolite concentration. Although there are various studies that indicate the ability of the DART to detect drug compounds, there are no known studies that have examined how real-world urine samples are analyzed. Additionally, there are no current studies that take into consideration adulteration of the urine sample using the DART method. The results obtained in the study showed the ability for DART to identify molecular protonated peaks indicative of dextroamphetamine and/or the presence of masking agents. While the other target drugs could not be identified using this method, the identification of dextroamphetamine, adulterant products and the deuterated internal standard show promise in using this as a screening technique prior to confirmatory tests. Future work is currently being conducted to optimize the protocol for the evaluation of THC, cocaine and benzodiazepines.
Show less - Date Issued
- 2019
- Identifier
- CFH2000538, ucf:45623
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000538
- Title
- PATTERNED CELL CULTURES FOR HIGH THROUGHPUT STUDIES OF CELL ELECTROPHYSIOLOGY AND DRUG SCREENING APPLICATIONS.
- Creator
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Natarajan, Anupama, Hickman, James, University of Central Florida
- Abstract / Description
-
Over the last decade, the field of tissue and bio-engineering has seen an increase in the development of in vitro high-throughput hybrid systems that can be used to understand cell function and behavior at the cellular and tissue levels. These tools would have a wide array of applications including for implants, drug discovery, and toxicology, as well as for studying cell developmental behavior and as disease models. Currently, there are a limited number of efficient, functional drug...
Show moreOver the last decade, the field of tissue and bio-engineering has seen an increase in the development of in vitro high-throughput hybrid systems that can be used to understand cell function and behavior at the cellular and tissue levels. These tools would have a wide array of applications including for implants, drug discovery, and toxicology, as well as for studying cell developmental behavior and as disease models. Currently, there are a limited number of efficient, functional drug screening assays in the pharmacology industry and studies of cell-surface interactions are complicated and invasive. Most cell physiology studies are performed using conventional patch-clamp techniques or random networks cultured on silicon devices such as Microelectrode Arrays (MEAs) and Field Effect transistors (FETs). The objective of this study was to develop high-throughput in vitro platforms that could be used to analyze cell function and their response to various stimuli. Our hypothesis was that by utilizing surface modification to provide external guidance cues for various cell types and by controlling the cell environment in terms of culture conditions, we could develop an in vitro hybrid platform for sensing and testing applications. Such a system would not only give information regarding the surface effects on the growth and behavior of cells for implant development applications, but also allow for the study of vital cell physiology parameters like conduction velocity in cardiomyocytes and synaptic plasticity in neuronal networks. This study outlines the development of these in vitro high throughput systems that have varied applications ranging from tissue engineering to drug development. We have developed a simple and relatively high-throughput method in order to test the physiological effects of varying chemical environments on rat embryonic cardiac myocytes in order to model the degradation effects of polymer scaffolds. Our results, using our simple test system, are in agreement with earlier observations that utilized a complex 3D biodegradable scaffold. Thus, surface functionalization with self-assembled monolayers combined with histological/physiological testing could be a relatively high throughput method for biocompatibility studies and for the optimization of the material/tissue interface in tissue engineering. Traditional multielectrode extracellular recording methods were combined with surface patterning of cardiac myocyte monolayers to enhance the information content of the method; for example, to enable the measurement of conduction velocity, refractory period after action potentials or to create a functional reentry model. Two drugs, 1-Heptanol, a gap junction blocker, and Sparfloxacin, a fluoroquinone antibiotic, were tested in this system. 1-Heptanol administration resulted in a marked reduction in conduction velocity, whereas Sparfloxacin caused rapid, irregular and unsynchronized activity, indicating fibrillation. As shown in these experiments, the patterning of cardiac myocyte monolayers increased the information content of traditional multielectrode measurements. Patterning techniques with self-assembled monolayers on microelectrode arrays were also used to study the physiological properties of hippocampal networks with functional uni-directional connectivity, developed to study the mono-synaptic connections found in the dentate gyrus. Results indicate that changes in synaptic connectivity and strength were chemically induced in these patterned hippocampal networks. This method is currently being used for studying long term potentiation at the cellular level. For this purpose, two cell patterns were optimized for cell migration onto the pattern as demonstrated by time lapse studies, and for supporting the best pattern formation and cell survival on these networks. The networks formed mature interconnected spiking neurons. In conclusion, this study demonstrates the development and testing of in vitro high-throughput systems that have applications in drug development, understanding disease models and tissue engineering. It can be further developed for use with human cells to have a more predictive value than existing complex, expensive and time consuming methods.
Show less - Date Issued
- 2010
- Identifier
- CFE0003384, ucf:48437
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003384