Digital Commons Network^™

Towards An Understanding Of Pharmacologically Induced Intracellular Changes In Nicotinic Acetylcholine Receptors: A Fluorescence Microscopy Approach, Ashley M. Loe

Theses and Dissertations--Chemistry

Upregulation of nicotinic acetylcholine receptors (nAChRs) is a well-documented response to chronic nicotine exposure. Nicotinic acetylcholine receptors are pentameric ligand-gated ion channels consisting of alpha (α2-10) and beta (β2-4) subunits. Nicotine, an agonist of nAChRs, alters trafficking and assembly of some subtypes of nAChRs, leading to an increase in expression of high sensitivity receptors on the plasma membrane. These physiological changes in nAChRs are believed to contribute to nicotine addiction, although the mechanism of these processes has not been resolved. Recently, many studies have converged on the idea that nicotine induces upregulation by an intracellular mechanism. In this dissertation, expression …

Organometallic Materials: Ferroceno[C]Thiophenes And 1,2-Bisthienylmetallocenes, Surya R. Banks

Theses and Dissertations--Chemistry

Development of synthetic routes toward two general organometallic frameworks was undertaken. The first project involved synthetic attempts of substituted and unsubstituted ferroceno[c]thiophene while the second one was the synthesis of 1,2-dithienylmetallocenes. The long-term goal of this work is to lay the foundations for study of electronic, electrochromic, redox, and optical properties of thiophene-based materials integrated with organometallic systems such as ferrocene, ruthenocene and cymantrene. The synthetic pathway for the target molecule in the first project involved converting 1,2-bis(hydroxymethyl)ferrocene to 1,2-bis(thiouroniummethyl)ferrocene with thiourea under acidic conditions. Refluxing the salt in base followed by acidification resulted in 1,2-bis(mercaptomethyl)ferrocene, which is …

Bioactive Poly(Beta-Amino Ester) Biomaterials For Treatment Of Infection And Oxidative Stress, Andrew L. Lakes

Theses and Dissertations--Chemical and Materials Engineering

Polymers have deep roots as drug delivery tools, and are widely used in clinical to private settings. Currently, however, numerous traditional therapies exist which may be improved through use of polymeric biomaterials. Through our work with infectious and oxidative stress disease prevention and treatment, we aimed to develop application driven, enhanced therapies utilizing new classes of polymers synthesized in-house. Applying biodegradable poly(β-amino ester) (PBAE) polymers, covalent-addition of bioactive substrates to these PBAEs avoided certain pitfalls of free-loaded and non-degradable drug delivery systems. Further, through variation of polymer ingredients and conditions, we were able to tune degradation rates, release profiles, cellular …

Synthesis And Characterization Of Antioxidant Conjugated Poly(Βeta-Amino Ester) Micro/Nanogels For The Suppression Of Oxidative Stress, Prachi Gupta

Theses and Dissertations--Chemical and Materials Engineering

Oxidative stress is a pathophysiological condition defined by an increased production of reactive oxygen species (ROS), which can result in the growth arrest of cells followed by cell disintegration or necrosis. A number of small molecule antioxidants (e.g. curcumin, quercetin and resveratrol) are capable of directly scavenging ROS, thereby short-circuiting the self-propagating oxidative stress state. However, poor solubility and rapid 1^st pass metabolism results in overall low bioavailability and acts as a barrier for its use as a drug to suppress oxidative stress efficiently.

To overcome this limitation, these small molecule antioxidants were covalently conjugated into poly(β-amino ester) (PβAE) …

Peptide-Functionalized Magnetic Nanoparticles For Cancer Therapy Applications, Anastasia K. Hauser

Theses and Dissertations--Chemical and Materials Engineering

Lung cancer is one of the leading causes of cancer deaths in the United States. Radiation and chemotherapy are conventional treatments, but they result in serious side effects and the probability of tumor recurrence remains high. Therefore, there is an increasing need to enhance the efficacy of conventional treatments. Magnetic nanoparticles have been previously studied for a variety of applications such as magnetic resonance imaging contrast agents, anemia treatment, magnetic cell sorting and magnetically mediated hyperthermia (MMH). In this work, dextran coated iron oxide nanoparticles were developed and functionalized with peptides to target the nanoparticles to either the extracellular matrix …

Design Of Highly Stable Low-Density Self-Assembled Monolayers Using Thiol-Yne Click Reaction For The Study Of Protein-Surface Interactions, Leila Safazadeh Haghighi

Theses and Dissertations--Chemical and Materials Engineering

Protein adsorption on solid surfaces is a common yet complicated phenomenon that is not fully understood. Self-assembled monolayers have been utilized in many studies, as well-defined model systems for studying protein-surface interactions in the atomic level. Various strategies, including the use of single component SAMs[1, 2], combinations of long and short alkanethiolates with methyl- and hydroxyl- terminal groups[3, 4], and using mixtures of alkanethiolates with similar chain length and varying terminal functional group [5] have been used to effectively control the surface wettability and determine the effect of surface composition and wettability on protein adsorption. In this dissertation we report …

Understanding Dna Condensation By Low Generation (G0/G1) And Zwitterionic G4 Pamam Dendrimers, Min An

Theses and Dissertations--Chemistry

Cationic polymers have shown potential as gene delivery vectors due to their ability to condense DNA and protect it from cellular and restriction nucleases. Dendrimers are hyperbranched macromolecules with precisely defined molecular weights and highly symmetric branches stemming from a central core. The nanosize, tunable surface chemistries and ease of surface functionalization has made dendrimers an attractive alternative to conventional linear polymers for DNA delivery applications. The commercially available, cationic dendrimer poly(amidoamine) or PAMAM is the most widely studied dendrimer for use as a gene delivery vector. The aim of this dissertation is to provide an increased understanding of the …

Design, Synthesis And Physicochemical Analysis Of Ruthenium(Ii) Polypyridyl Complexes For Application In Phototherapy And Nucleic Acid Sensing, Erin Melissa Wachter

Theses and Dissertations--Chemistry

Current chemotherapeutics exhibit debilitating side effects as a result of their toxicity to healthy tissues. Reducing these side effects by developing chemotherapeutics with selectivity for cancer cells is an active area of research. Phototherapy is one promising modality for selective treatment, where drug molecules are “turned on” when irradiated with light, reducing damage to healthy tissues by spatially restricting the areas exposed to irradiation. A second approach to improve selectivity is to exploit the differences in cancerous versus healthy cells, such as increased metabolism and/or upregulation of cell surface receptors. Ruthenium(II) polypyridyl complexes are candidates for phototherapy due to their …

Towards Catalytic Oxidative Depolymerization Of Lignin, Justin K. Mobley

Theses and Dissertations--Chemistry

Lignin is one of the most abundant and underutilized biopolymers on earth. Primarily composed on three monolignol units (sinapyl, coniferyl, and p-coumaryl alcohol), lignin is formed through a radical pathway resulting in an assortment of linkages, of which the β-O-4 linkage is the most prevalent (up to 60% in some hardwood species). In planta, lignin plays an important role in water transport and in protecting plants from chemical and biological attack. Traditional attempts to depolymerize lignin have focused on the cleavage of β-O-4 linkages via thermal or reductive routes. However these pathways lead to low-value, unstable product mixtures. Moreover, …

The Development Of Colorimetric Assays To Determine The Identity And Frequency Of Specific Nucleobases In Dna Oligomers, Elizabeth Marie Thomas

Theses and Dissertations--Chemistry

Colorimetric methods combined with color-changing chemical probes are widely used as simple yet effective tools for identifying and quantifying a wide variety of molecules in solution. For nucleic acids (DNA and RNA), perhaps the most commonly used colorimetric probe is potassium permanganate, which can be used to identify single-stranded pyrimidines (thymine and cytosine) in polymers. Unfortunately, permanganate is not an effective probe for identifying purines (adenine and guanine), especially in the presence of the more reactive pyrimidines. Therefore, robust methods for discriminating between the purines remain elusive, thereby creating a barrier toward developing more complex colorimetric applications. In this dissertation, …

Assembly And Degradation Of A Trimeric Membrane Protein Acrb, Qian Chai

Theses and Dissertations--Chemistry

Multidrug efflux pumps are membrane proteins that actively transport foreign objects out of cells. The active efflux of these pumps is a critical self-defense mechanism that enables the survival of bacteria under hostile environments. Efflux pump AcrB is a member of the Resistance-Nodulation-Division (RND) super family. In E. coli, it associates with periplasmic protein AcrA and outer membrane channel TolC to extrude a variety of noxious compounds out of cell from both the cytoplasm and the periplasm. My dissertation research focused on two aspects of this multidrug efflux pump: the oligomerization process during the biogenesis of AcrB and its …

In Vivo-Expressed Proteins Of Virulent Leptospira Interrogans Serovar Autumnalis N2 Elicit Strong Igm Responses Of Value In Conclusive Diagnosis, Veerapandian Raja, Santhanam Shanmughapriya, Murugesan Kanagavel, Sergey Artiushin, Sridhar Velineni, John F. Timoney, Kalimuthusamy Natarajaseenivasan

Maxwell H. Gluck Equine Research Center Faculty Publications

Leptospirosis is a serious zoonosis that is underdiagnosed because of limited access to laboratory facilities in Southeast Asia, Central and South America, and Oceania. Timely diagnosis of locally distributed serovars of high virulence is crucial for successful care and outbreak management. Using pooled patient sera, an expression gene library of a virulent Leptospira interrogans serovar Autumnalis strain N2 isolated in South India was screened. The identified genes were characterized, and the purified recombinant proteins were used as antigens in IgM enzyme-linked immunosorbent assay (ELISA) either singly or in combination. Sera (n = 118) from cases of acute leptospirosis along …

Cognitive And Behavioral Mechanisms Underlying Alcohol-Induced Risky Driving, Jennifer R. Laude

Theses and Dissertations--Psychology

Alcohol intoxication represents one situation an individual might increase their amount of risk taking when driving. This dissertation is comprised of three studies that investigate the mechanisms by which alcohol increases driver risk-taking. Study 1 examined the effect of alcohol on driver risk-taking using a proxemics approach. The study also tested whether alcohol-induced increases in risky driving co-occurred with pronounced impairment in the driver’s skill. The study also examined whether the most disinhibited drivers were also the riskiest. Indeed, alcohol increased driver risk-taking and impaired driving skill. The study also revealed risky driving can be dissociable from impairing effects on …

Categorical Perception Of Species In Infancy, Hannah B. White

Theses and Dissertations--Psychology

Although there is a wealth of knowledge on categorization in infancy, there are still many unanswered questions about the nature of category representation in infancy. For example, it is yet unclear whether categories in infancy have well-defined boundaries or what knowledge about species categories young infants have before entering the lab. Using a morphing technique, we linearly altered the proportion of cat versus dog in images and observed how infants reacted to contrasts between pairs of images that either did or did not cross over the categorical boundary. This was done while equating between-category and within-category similarity. Results indicate that …

Investigating The Role Of Social Support, Cardiovascular Reactivity, And Self-Regulation Skills Training In Response To Thermal Stimuli, Tracey Christine Kniffin

Theses and Dissertations--Psychology

Persistent pain conditions are a major health problem throughout the world and are one of the primary reasons that people seek medical treatment (Gureje, Von Korff, Simon, & Gater, 1998; Verhaak, Kerssens, Dekker, Sorbi, & Bensing, 1998). These conditions are characterized by complex interactions between cognitive, emotional, and physiological disturbances and are often associated with comorbid psychological disorders (Gatchel, 2004). Though previous studies have examined the effect of interventions targeting persistent pain, such as physical self-regulation interventions, few studies have examined the complex interaction between such interventions and other variables such as psychological and physiological …

Validity Of Immediate Post-Concussion Assessment And Cognitive Testing (Impact), Lisa Mason Koehl

Theses and Dissertations--Psychology

Sports concussions have been recognized as significant injuries among young athletes with research demonstrating that return-to-play prior to becoming asymptomatic can have significant repercussions, including risk of sustaining cognitive deficits. In tracking and monitoring concussions during sports seasons, many programs have begun utilizing computerized testing rather than traditional neuropsychological tests to 1) determine baseline scores, 2) track symptoms, and 3) measure cognitive deficits following concussion.

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is one such instrument. The current study examined ImPACT’s convergent, discriminant, and diagnostic validity by comparing scores from post-concussion athletes (SPORT) to those from non-concussed controls (CONT). SPORT …

Trait-Based Profiles Of Adhd In Adolescents And Young Adults, Tess E. Smith

Theses and Dissertations--Psychology

Empirical work has examined the utility of using person-centered statistical approaches emphasizing traits to parsing Attention-Deficit/Hyperactivity disorder (ADHD) heterogeneity in preschool and school-aged children. However, trait-based profiles have not yet been examined in other age ranges, specifically adolescence and young adulthood. Therefore, the goal of the present study is to examine trait-based profiles in adolescents and young adults with ADHD in order to evaluate their similarity with trait-based profiles in preschoolers and children with ADHD and through comparison with external correlates (e.g., comorbidity). One hundred and eighty-two adolescents and 287 young adults completed measures of ADHD symptoms, personality and temperament …

Psychosocial Functioning In Adolescents With Temporomandibular Disorders, Monica L. Gremillion

Theses and Dissertations--Psychology

Psychosocial functioning is a key component of screening and treatment of Temporomandibular Disorders (TMD) in adults; however, psychosocial functioning in adolescents with TMD has received little empirical attention. The present study aims to examine group difference between adolescents and adults with TMD on pain and prominent psychosocial factors, such as anxiety, depression, and somatization, as well as to explore additional developmentally sensitive psychosocial factors that may be associated more with the adolescent TMD pain.

Participants included 35 adolescents aged 12-17 (M=14.89 years, SD=1.84) with TMD muscle pain who completed pain questionnaires and a comprehensive dental examination. Patients …

Novel Spoxazomicins Derived From Streptomyces Sp. Rm-14−6 Attenuate Ethanol Induced Cytotoxicity In Vitro, Meredith A. Saunders

Theses and Dissertations--Psychology

An estimated 13.9% of Americans currently meet criteria for an alcohol use disorder. Ultimately, chronic alcohol use may result in neurological deficits, with up to 85% of alcoholics exhibiting signs of cognitive decline. However, biochemical and behavioral factors contributing to this decline have remained elusive. Our ongoing research program encompasses a multi-tiered screening of a natural product library and validation process to provide novel information about mechanisms underlying these deficits and to identify novel chemical scaffolds to be exploited in the development of pharmacological treatments for alcohol use disorders in a rodent organotypic hippocampal slice culture mode. Experiment 1 sought …

Loss Aversion In Cocaine Users: Influence Of Risk And Commodity Type, Justin Charles Strickland

Theses and Dissertations--Psychology

Numerous studies in behavioral economics have demonstrated that individuals are more sensitive to the prospect of a loss than a gain (i.e., loss aversion). Although loss aversion has been well described in healthy populations, little research exists in individuals with substance use disorders. The purpose of this study was to comprehensively evaluate loss aversion in cocaine users. Participants completed measures designed to assess loss aversion for drug and non-drug commodities under varying risk conditions. Cocaine demand was determined using a cocaine purchase task. Cocaine users showed a loss aversion score that was consistent across commodity and risk conditions. Compared to …

Ovarian Hormones, Adhd, Risk-Taking, & Impulsivity, Bethan A. Roberts

Theses and Dissertations--Psychology

Attention-Deficit/Hyperactivity Disorder (ADHD) is a highly impairing disorder of inattention, hyperactivity, and impulsivity that is more frequently diagnosed in males versus females at a ratio of 3:1. However, females with the disorder become highly impaired during adolescence, perhaps due to the onset of cycling ovarian hormones at puberty. The present study empirically assessed the role of the major female sex hormones, estrogen and progesterone, in the presentation of ADHD symptoms, impulsivity, and associated risk-taking behaviors (e.g., risky sex, substance use and abuse) in a non-clinical sample of young adult women. 32 healthy young adult women who were screened for hormonal …

Adaptability In A Bhutanese Refugee Community: Navigating Integration And The Impacts On Nutritional Health After U.S. Resettlement, Chris Grosh

Theses and Dissertations--Anthropology

Increasing rates of overweight, obesity, and related metabolic diseases documented among refugee communities across the United States necessitate greater attention to how processes of integration impact refugee health. These nutritional health trends (e.g., increasing rates of obesity) suggest potential disconnects between refugees' past environments and their conditions after re-settlement, which may contribute to adverse changes in energy balance (diet and exercise). While Bhutanese refugees were among the largest refugee groups entering the US during the five years leading up to this research, very few studies have examined how they have responded to integration and the impact of this transition on …

Thermophilic Phosphatases And Methods For Processing Starch Using The Same, Matthew S. Gentry, Craig W. Vander Kooi

Molecular and Cellular Biochemistry Faculty Patents

The presently-disclosed subject matter includes thermophilic glucan phosphatase polypeptides. In some embodiments the polypeptide includes non-native laforin polypeptides, or fragments and/or variants thereof, and in some instances the polypeptide can alter the biophysical properties of starch in vitro or in planta. The presently-disclosed subject matter also includes isolated polynucleotides encoding the present polypeptides, methods for processing starch by exposing starch to the present polypeptides, and methods for making the present polypeptides.

Consequences Of Shifts In Abundance And Distribution Of American Chestnut For Restoration Of A Foundation Forest Tree, Harmony J. Dalgleish, Charles Dana Nelson, John A. Scrivani, Douglass F. Jacobs

Forestry and Natural Resources Faculty Publications

Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States Department of Agriculture Forest Service Forest Inventory and Analysis data to quantify the current density and distribution of C. dentata. We then review the literature concerning biogeographic patterns in C. dentata. Currently, 431 ± 30.2 million stems remain. The vast majority (360 ± 22 million) are sprouts < 2.5 cm dbh. Although this number is approximately 10% of the estimated pre-blight population, blight has caused a major shift in the size structure. The current-day population has a larger range, particularly west and north, likely due to human translocation. While climate change could facilitate northward expansion, limited seed reproduction makes this unlikely without assisted migration. Previous research demonstrates that the current, smaller population contains slightly higher genetic diversity than expected, although little information exists on biogeographic patterns in the genetics of adaptive traits. Our research provides a baseline characterization of the contemporary population of C. dentata, to enable monitoring stem densities …

Development And Preliminary Evaluation Of A Spray Deposition Sensing System For Improving Pesticide Application, Melissa A. Kesterson, Joe D. Luck, Michael P. Sama

Biosystems and Agricultural Engineering Faculty Publications

An electronic, resistance-based sensor array and data acquisition system was developed to measure spray deposition from hydraulic nozzles. The sensor surface consisted of several parallel tin plated copper traces of varying widths with varying gap widths. The system contained an embedded microprocessor to monitor output voltage corresponding to spray deposition every second. In addition, a wireless module was used to transmit the voltage values to a remote laptop. Tests were conducted in two stages to evaluate the performance of the sensor array in an attempt to quantify the spray deposition. Initial tests utilized manual droplet placement on the sensor surface …

Rna-Sequencing Reveals Global Transcriptomic Changes In Nicotiana Tabacum Responding To Topping And Treatment Of Axillary-Shoot Control Chemicals, Sanjay Kumar Singh, Yongmei Wu, Jayadri S. Ghosh, Sitakanta Pattanaik, Colin Fisher, Ying Wang, Darlene Lawson, Ling Yuan

Kentucky Tobacco Research and Development Center Faculty Publications

Removal of terminal buds (topping) and control of the formation of axillary shoots (suckers) are common agronomic practices that significantly impact the yield and quality of various crop plants. Application of chemicals (suckercides) to plants following topping is an effective method for sucker control. However, our current knowledge of the influence of topping, and subsequent suckercide applications, to gene expression is limited. We analyzed the differential gene expression using RNA-sequencing in tobacco (Nicotiana tabacum) that are topped, or treated after topping by two different suckercides, the contact-localized-systemic, Flupro^® (FP), and contact, Off-Shoot-T^®. Among the differentially …

The Visual Priming Of Motion-Defined 3d Objects, Xiong Jiang, Yang Jiang, Raja Parasuraman

Behavioral Science Faculty Publications

The perception of a stimulus can be influenced by previous perceptual experience, a phenomenon known as perceptual priming. However, there has been limited investigation on perceptual priming of shape perception of three-dimensional object structures defined by moving dots. Here we examined the perceptual priming of a 3D object shape defined purely by motion-in-depth cues (i.e., Shape-From-Motion, SFM) using a classic prime-target paradigm. The results from the first two experiments revealed a significant increase in accuracy when a "cloudy" SFM stimulus (whose object structure was difficult to recognize due to the presence of strong noise) was preceded by an unambiguous SFM …

Selection Of Reference Genes For Rt-Qpcr Analysis In A Predatory Biological Control Agent, Coleomegilla Maculata (Coleoptera: Coccinellidae), Chunxiao Yang, Huipeng Pan, Jeffrey Edward Noland, Deyong Zhang, Zhanhong Zhang, Yong Liu, Xuguo Zhou

Entomology Faculty Publications

Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a reliable technique for quantifying gene expression across various biological processes, of which requires a set of suited reference genes to normalize the expression data. Coleomegilla maculata (Coleoptera: Coccinellidae), is one of the most extensively used biological control agents in the field to manage arthropod pest species. In this study, expression profiles of 16 housekeeping genes selected from C. maculata were cloned and investigated. The performance of these candidates as endogenous controls under specific experimental conditions was evaluated by dedicated algorithms, including geNorm, Normfinder, BestKeeper, and ΔCt method. In addition, …

Linker Histone H1 And H3k56 Acetylation Are Antagonistic Regulators Of Nucleosome Dynamics, Morgan Bernier, Yi Luo, Kingsley C. Nwokelo, Michelle Goodwin, Sarah J. Dreher, Pei Zhang, Mark R. Parthun, Yvonne N. Fondufe-Mittendorf, Jennifer J. Ottesen, Michael G. Poirier

Molecular and Cellular Biochemistry Faculty Publications

H1 linker histones are highly abundant proteins that compact nucleosomes and chromatin to regulate DNA accessibility and transcription. However, the mechanisms that target H1 regulation to specific regions of eukaryotic genomes are unknown. Here we report fluorescence measurements of human H1 regulation of nucleosome dynamics and transcription factor (TF) binding within nucleosomes. H1 does not block TF binding, instead it suppresses nucleosome unwrapping to reduce DNA accessibility within H1-bound nucleosomes. We then investigated H1 regulation by H3K56 and H3K122 acetylation, two transcriptional activating histone post translational modifications (PTMs). Only H3K56 acetylation, which increases nucleosome unwrapping, abolishes H1.0 reduction of TF …

High-Activity Mutants Of Butyrylcholinesterase For Cocaine Hydrolysis And Method Of Generating The Same, Chang-Guo Zhan, Hoon Cho, Hsin-Hsiung Tai

Pharmaceutical Sciences Faculty Patents

A novel computational method and generation of mutant butyrylcholinesterase for cocaine hydrolysis is provided. The method includes molecular modeling a possible BChE mutant and conducting molecular dynamics simulations and hybrid quantum mechanical/molecular mechanical calculations thereby providing a screening method of possible BChE mutants by predicting which mutant will lead to a more stable transition state for a rate determining step. Site-directed mutagenesis, protein expression, and protein activity is conducted for mutants determined computationally as being good candidates for possible BChE mutants, i.e., ones predicted to have higher catalytic efficiency as compared with wild-type BChE. In addition, mutants A199S/A328W/Y332G, A199S/F227A/A328W/Y332G, A199S/S287G/A328W/Y332G, …