Physical Sciences and Mathematics Commons^™

Studies On Regulation Of Dihydrotestosterone Binding To And Releasing From The Androgen Receptor, Tahyra M. Resto Santos

Theses and Dissertations

The androgen receptor (AR) is a nuclear receptor that responds to testosterone and 5α-dihydrotestosterone (DHT) by modulating gene expression in a variety of cells, including prostate and muscle tissues. Studies of small molecule interaction with AR have shown diphenyl compounds inhibiting through a binding site labeled Binding Function 3 (BF3). The goal of this research is to analyze the interaction of the BF3 site with DDT and related compounds. Amino acids that are exposed on the surface of the BF3 that might interact with different compounds were mutated. Mutant proteins were tested experimentally for their impact on the inhibition the …

Molten-Salt Synthesized Pyrochlore Nanoparticles For Multifunctional Applications, Jose P. Zuniga

Theses and Dissertations

There is a need in the scientific world to design and develop high quality nanomaterials with multifunctional applications. In this work, we explore the molten-salt method (MSS) as a new green method for the synthesis of complex metal oxides. We adjusted all synthesis parameters such as time, temperature and pH to generate an optimum La2Hf2O7 nanoparticle with a well define shape and surface. Activator ions such as Eu3+, Tb3+, Dy3+, Bi3+ and uranium ion (U4+, U6+) were used to monitor its structural and optical behavior effect when doped.

Our results showed effective quantum yield, thermal, pressure stability, near to white …

The Development Of Screening Platforms To Identify Novel Anti-Infectives That Inhibit Protein Synthesis In Pseudomonas Aeruginosa, Casey Anne Hughes

Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, is a leading cause of nosocomial infections and is becoming increasingly antibiotic resistant. Aminoacyl-tRNA synthetases (aaRSs) catalyze the covalent attachment of amino acids to their cognate tRNAs and serve as validated targets for the development of new anti-infectives. In P. aeruginosa, the genome contains two genes (tyrS and tyrZ) which encode two distinct TyrRS enzymes. The genes encoding both P. aeruginosa TyrRS-Z and TyrRS-S were cloned, overexpressed in E. coli cells, and purified to homogeneity. Both forms of TyrRS were active in aminoacylation and were developed into screening platforms using scintillation proximity …

Effects On Altering Reaction Conditions In Suzuki Cross Coupling Reactions Using The Microwave, Javier Alejandro Perez

Theses and Dissertations

Over the last few decades, Suzuki coupling has become a common process for the synthesis of intermediates in pharmaceutical and industrial applications. It is well known that palladium is an effective catalyst for the formation of cross-coupled products. Therefore, this catalyst was tested in a series of reactions. Also, it is believed that other catalyst with similar properties to palladium can work, for example cerium. Therefore, a cerium hydroxide catalyst was synthesized in lab and used as a potential catalyst for the Suzuki reaction. For this study, some bases were investigated (NaOH, Na2CO 3, K3PO4, NaNO3, NaHCO3, etc) for the …

Photocatalytic Degradation Of Simazine Using Zno/Go Composites, Kenneth Ray Flores

Theses and Dissertations

The photocatalytic degradation of simazine (SIM) by Zinc oxide/graphene oxide (ZnO/GO) composites, under visible light irradiation, was investigated to determine various reaction parameters, of initial pH, ZnO loading on GO, and catalyst mass. A pH of 2 was determined to be the optimal reaction pH for all ZnO/GO catalysts. A loading mass of 40mg for the 20 & 30mmol composites; whereas a 10mg mass was determined to be most effective for the 10mmol composite. The reaction followed second order kinetics for the degradation process, the reaction dependence was determined to be on the concentration of SIM in solution. All ZnO/GO …

Green Synthesis/Biosynthesis Of Silver Nanoparticles By Using Orange Peel Extract, Leela Joshi

Theses and Dissertations

Joshi, Leela, Green Synthesis/Biosynthesis of Silver Nanoparticles by Using Orange Peel Extract. Master of Science (MS), December, 2018, 40 pages, 23 figures, references, 36 titles. In this work, we report synthesis of silver nanoparticles (AgNPs) with an average size of ~6 nm. The aqueous solution of Ag+ ions is reduced using an aqueous extract from orange peel (Citrus Sinensis) at varying pHs. Reduction of Ag+ ions in solution was monitored using UV-visible absorption spectroscopy, and the corresponding surface plasmon resonance of AgNPs at 435 nm. The solution changed color from yellow to reddish-brown upon bioreduction of silver nitrate in orange …

Three Dimensional Carbon Nanotube Yarn Based Perovskite Solar Cells, Istiak Hussain

Theses and Dissertations

Perovskite solar cells (PSC) have emerged as a promising photovoltaic technology in lab scale with a short time of research due to their high power conversion efficiency, simple device fabrication, all solid-state structure and the possibility to ingrate the traditional device into fiber format. In this work, a three-dimensional (3D) perovskite solar cell is demonstrated using functionalized carbon nanotube yarn (CNT) as both cathode and anode. TiO2 and 2,2,7,-7-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD) are used as the electron transporting and hole transporting material respectively. The TiO2 oxide layer is deposited on the top of the twisted carbon nanotube yarn and annealed with TiCl4 …

Functionalized And Nanostructured Fibers For Photocatalysis And Energy Conversion, Jared R. Jaksik

Theses and Dissertations

Fiber-type / flexible materials present a unique opportunity for the incorporation of photocatalytic / energy generating technology, as they typically have a broad surface area exposed to light (clothing, curtains, carpet). In this work, several methods of harvesting incident light striking a flexible substrate to perform useful work are examined. In the first section a gold and silver nanoparticle augmented TiO2 thin film textile coating is evaluated for its self-cleaning / UV-protective / anti-microbial properties, and stability of the film / substrate over time is examined. In the second section a dye sensitized / hybrid type solar cell architecture based …

Experimental And Computational Studies Of Rotation And Proton Tunneling In Organic Molecules And Molecular Dimers, Agapito Serrato Iii

Theses and Dissertations

An introduction to the relations of classical and quantum mechanics are presented in brief. As is an overview of the instrumentation and quantum chemical analysis performed to characterize the molecules presented in in this thesis. The pure rotational spectrum of 3,3,3-trifluoro-2(trifluoromethyl)propanoic acid, perfluorobutyric acid–formic acid dimer, and tropolone–formic acid dimer were measured using high-resolution microwave spectroscopy. The spectra have been observed using a cavity-based Fourier-transform microwave (FTMW) spectrometer and/or a chirped-pulse FTMW.

Microwave-Assisted Ring-Opening Polymerization Of Poly(Ε-Caprolactone), Nancy Obregon

Theses and Dissertations

Poly(ϵ-caprolactone) (PCL) is a biodegradable polyester notorious by its promising properties and applications in the biomedical field. In this work, microwave-assisted ringopening polymerization (ROP) of ϵ-caprolactone (ϵ-CL) was performed. Stannous octoate [Sn(Oct)2] was used as catalyst with and without an alcohol initiator. The different initiators tested were glycerol, diethylene glycol (DEG) and poly(ethylene) glycol (PEG). Aiming to establish reaction parameters, the influence of different reaction times, temperatures, and monomer:initiator:catalyst ratios were examined. It was observed that the reaction was obtained and high molecular weight PCL was achieved successfully without an initiator. However, mixed results were obtained using an initiator. Products …

Removal Of Chromium(Vi) And Chromium(Iii) Ions From Aqueous Solution Using Bio-Char Generated From Agricultural Waste Products, Diego Fernando Gonzalez

Theses and Dissertations

Heavy metals are one of the most persistent and prevalent contaminants in the aquatic environment. The removal of chromium from aqueous solution, especially in the hexavalent form is difficult. New technologies, techniques and/or new materials have been designed in order to effectively and efficiently remove chromium from the aqueous environment. The project focuses on the comparison of the effects of pH, time, temperature, binding capacity on bio-char’ generated from agricultural waste produces vs an amino modified derivative of the bio-char. Pineapple skins were dried, ground, sieved, and pyrolyzed to produce a bio-char material. The bio-char was analyzed using FTIR to …

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sufone Using A Molybdenum (Vi) Oxide Catalyst: A Kinetic Study Testing Solvent Dependency And Mole Ratio Efficiency, Tomas Trevino Jr.

Theses and Dissertations

Oxidative desulfurization (ODS) is currently a solution to hydrodesulphurization. Currently, industrial usage of hydrodesulphurization (HDS) is the common source for petroleum purification. Unfortunately, HDS comes with environmental and economical ramifications. Due to the problems and potential hazards being presented with HDS, ODS has become a topic of interest in research development. A kinetic study using molybdenum (VI) oxide as a catalyst was used in oxidative desulfurization. Factors such as mole ratio and solvent dependency were tested for efficiency. As activation energy was calculated to show maximum efficiency with respect to temperature and concentration. Gas Chromatography, FT-IR, and Mass Spectroscopy were …

Hydrodesulfurization Of Dibenzothiophene Using Lanthanum Doped Comos2, Carolina Valdes Bracamontes

Theses and Dissertations

Hydrodesulfurization (HDS) is a technique used in petrochemical industry for the removal of sulfur from crude oil. Using dibenzothiophene (DBT) as a target molecule and CoMoS2 catalysts doped with various concentrations of lanthanum were studied for catalytic activity in the removal of DBT from solution. Catalysts were synthesized using ammonium tetrathiomolydate, cobalt chloride and lanthanum nitrate under a solvothermal decomposition in decalin at 350 °C with H2 gas at 160 psi. To evaluate decomposition effects, a second set of catalyst precursors were decomposed in a tube furnace at 450 °C under a constant flow of 10%/90% H2/Ar. Characterizations of the …

Synthesis Of Tetraethyl ((2-Amino-1,4-Phenylene)Bis(Methylene)) Bis(Phosphonate): An Intermediate In The Synthesis Of Amino-Substituted Conjugated Materials, Ariel Ivan Torres Burgueno

Theses and Dissertations

Discussed here are the syntheses of the phosphonate precursors for the Wittig-Horner synthesis of poly-phenylene vinylene (PPV) and distyrylbenzene (DSB) derivatives and their respective distyrylbenzene analogs containing amino moieties. The synthesis of the different compounds was achieved through bromination, Michaelis-Arbuzov reaction, reduction of the nitro group with a commercial cobalt sulfide catalyst and sodium borohydride. Preliminary evidence for the synthesis of amino substituted distyrylbenzene and of nitro/alkoxy substituted poly(p-phenylene vinylene) was obtained. Characterization of the products was performed by 1H-NMR. Preliminary results of the synthesis of a novel amino-substituted distyrylbenzene (DSB) are presented. The luminescence of the new DSB was …

Remediation Of Trivalent And Hexavalent Chromium Ions From Aqueous Solutions Using Titanium Dioxide Polymorphs, Yvette Cantu

Theses and Dissertations

Three titanium dioxide (TiO2) polymorphs were synthesized and used for the removal of chromium (III) and chromium (VI) from aqueous solutions. Various solution parameters were studied to determine the effects of pH, temperature, time, possible interfering ions, and capacities on the binding of Cr(III) and Cr(VI) to all three polymorphs. pH assays determined the optimum pH for the binding of both Cr(III) and Cr(VI) to each polymorph. Adsorption isotherms determined that the adsorption of Cr(III) was non-spontaneous for the three polymorphs with ΔG values ranging from 6.03 to 12.89 kJ/mol. Furthermore, the binding of Cr(VI) to anatase was also non-spontaneous …

Remediation Of Lead And Copper Ions From Water Solutions Using Transition Metal Sulfides, Jesus M. Cantu Jr.

Theses and Dissertations

Heavy metal contamination in water solutions has been a major concern since many transition metals don’t play a role in any biological function and are actually detrimental to human health. There have been several techniques that have been implemented for the remediation of heavy metal contaminants. For this project, three metal sulfides—Fe7S8, ZnS, TiS 2—were synthesized and studied for their capabilities to remove Pb(II) and Cu(II) from water solutions. Several parameters were investigated to determine the effects of pH, time, temperature, binding capacities, and interfering ions. The room temperature adsorption capacities ranged 6.23–333.3 mg/g for Pb(II) and 1.31–250 mg/g for …

Biocidal Defeat Agents Produced By Silver-Iodine Nanoenergetic Gas Generators, Ivan Davila

Theses and Dissertations

Nanostructured aluminum (Al), iodine pentoxide (I2O5) nano-rods, and silver oxide (Ag2O) nanoparticles, (Al-I2O5-Ag 2O) were used to compose the ternary thermite composition that serves as a Nanoenergetic Gas Generator (NGG). This composition produces biocidal gases giving the mixture the ability to destroy highly pathogenic microorganisms or bacteria. The dissemination of the biocidal gas in combustion chamber was observed using a high-speed camera. The testing of NGG combustion process against the living Escherichia coli (E.coli) K-12 strain cells, that were cultivated/placed on the sample/chamber surfaces, demonstrated that iodine and silver atoms clouds were deposited to the bacteria surface. The 10/75/15 wt …

Formation Of Lifepo4-Pan Submicron Fibers Via Forcespinning ® For Battery Cathode Applications, Ashlee L. Lopez

Theses and Dissertations

LiFePO4/C composite nanofibers were prepared by utilizing Forcespinning® technology and calcination approaches. Polyacrylonitrile (PAN) was dissolved in N, N-dimethylformamide (DMF) to produce the media that allotted nanofiber formation via Forcespinning® and also served as the carbon source. A LiFePO4 solution was synthesized separately in DMF, which served as the precursor. The separately prepared PAN/DMF and LiFePO4/DMF solutions were then mixed at different weight percent’s (wt.%) prior to being subjected to Forcespinning ®. Elemental analysis of the LiFePO4/PAN nanofibers was characterized by energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS). The study of the surface morphology was conducted by scanning …

Parameterization Of Ar231453: A Potent Agonist Of The Gpr119 Receptor, A Target For Diabetes Treatment, John E. Hamilton

Theses and Dissertations

The first reported potent agonist for the GPR119 receptor, a potential target for the treatment of diabetes, is 2-fluoro-4-methanesulfonyl-phenyl-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine (AR231453). The dynamic interactions of AR231453 with GPR119 using molecular dynamics simulation are of great interest. However, parameters for AR231453 that describe the behavior of the molecule in the CHARMM force field have not been determined. The following study produces parameters by creating model fragments and compares the produced parameters to quantum calculations. The produced parameters are then further refined within the Visual Molecular Dynamics (VMD) program’s plugin program, the Force Field Toolkit as well as Gaussian 09 and CHARMM. Molecular …

Hydrodesulfurization Of Dibenzothiophene Using Comos2, Jacob S. Sollner

Theses and Dissertations

The hydrodesulphurization (HDS) of crude oils is an important industrial process to remove sulfur from fuels. In this study, DBT was used as a model compound to study the removal of sulfur from a decahydronaphthalene solution. The catalyst was synthesized through low pressure pathways in the absence of H2S. All the synthesized catalyst were investigated using a combination of SEM, RAMAN spectroscopy, and XRD. The materials were studied for their ability to remove DBT from solution and the reaction products were analyzed. It was observed that the major reaction pathway was the direct desulphurization pathway and zero order reaction kinetics …

Molecular Dynamic Simulation Studies Of The Androgen Receptor Complexed With 5Α-Dihydrotestosterone And An Allosteric Ligand, Everardo Villarreal Ii

Theses and Dissertations

Receptors are important drug targets for the pharmaceutical industry, since they are involved in many illnesses. Nuclear receptors are a subset of receptors that control a variety of physiological events, by expression of genes from DNA. One of the nuclear receptors, the androgen receptor, is a steroid binding receptor that controls a variety of regulatory and development functions in the body. It is also the cause of some types of cancer, so the inhibition of this receptor is crucial. One of the processes studied to inhibit the function of the receptor is to see if an allosteric ligand, TRIAC, can …

Identification Of Synthetic Chemical Compound Inhibitors Of Pseudomonas Aeruginosa Protein Synthesis And The Development Of Lead Series, Stephanie O. Palmer

Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous Gram-negative bacteria and a primary cause of nosocomial infections. An aminoacylation/translation (A/T) assay was developed using P. aeruginosa components to perform poly(U) mRNA directed protein synthesis. Using scintillation proximity assay (SPA) technology a high-throughput screening (HTS) platform was developed. A synthetic chemical compound library (>900) was screened, 36 hit compounds were identified and molecular targets were determined. Compounds were analyzed for enzymatic inhibition (IC50) and inhibition of bacterial cultures (MIC). Time-kill studies determined bacterial growth to be bacteriostatic or bactericidal in the presence of inhibitor. Mechanism of action, effects on eukaryotic cytosolic and mitochondrial …

Facile Sol-Gel Molten Salt Synthesis Of Double Perovskite La 2nimno6 As An Electrocatalyst For Oxygen Evolution Reactions, Padmini Kukkapalli

Theses and Dissertations

Double perovskites have attracted a great attention recently for its high intrinsic activity in oxygen evolution reaction (OER) in electrochemical energy storage and conversion systems in alkaline media. In this study, we are the first to report the new approach of La2NiMnO6 double perovskite which was synthesized via Sol-gel molten-Salt synthesis method. However their stability and specific activity remain challenging that need to be addressed to meet the reqiurement for OER activities. Here in this study we synthesized three different samples with varying concentrations by taking molten salts NaNO 3 and KNO3 in (1:1) ratio such as 30:30, 60:60, 90:90. …

Molecular Modeling And Mutational Mapping Of The Gpr119 Binding Site, Shane M. Askar

Theses and Dissertations

GPR119 receptor’s biological role in regulating glucose homeostasis has been studied extensively. Results in the scientific literature indicate that, when activated, GPR119 releases insulin in a glucose dependent manner. Currently the 3D structure of GPR119 has not been resolved.

The goal of this research is to use a combination of homology modeling and ligand docking studies to predict the binding mode of GPR119 ligands. Amino acids implicated to have direct interactions with docked ligands will further be assessed experimentally for their roll in binding and activation of GPR119. Our results indicate that residues W2656.48 and R813.28 are likely to be …