Physical Sciences and Mathematics Commons^™

Functionalized Carbon Nanotubes In Hydrophobic Drug Delivery, Kun Chen

Dissertations

The direct incorporation of carboxylated carbon nanotubes (f-CNTs) into hydrophobic drug particles during their formation via anti-solvent precipitation is presented. The approach is tested using two drugs namely antifungal agent Griseofulvin (GF) and antibiotic Sulfamethoxazole (SMZ) that have very different aqueous solubility. It is observed that the f-CNTs dispersed in the water serve as nucleating sites for crystallization and are readily incorporated into the drug particles without altering crystal structure or other properties. The results show that the hydrophilic f-CNTs dramatically enhance dissolution rate for both drugs. The increased degree of functionalization leads to higher hydrophilicity and therefore faster dissolution …

Development Of Flexible Nickel-Zinc And Nickel-Iron Batteries, Xianyang Meng

Dissertations

The fabrication of flexible nickel-zinc batteries using a facile mixing of electroactive components for electrode preparation is presented. Polytetrafluoroethylene (PTFE) is found to be an effective binder by reducing concentration polarization, providing chemical/physical stability and enhancing flexibility. The zinc electrode containing PTFE maintains its original porous morphology even after hundreds of cycles while polymers such as PEO show morphology change. Each component, as well as the assembled flexible cells show desired flexibility and stability even under bending conditions.

The fabrication of flexible nickel-iron batteries using printable composite electrodes embedded with multiwalled carbon nanotubes (CNT) is also presented. All the metal …

Controls On Phosphorus Export From An Agricultural Watershed: Amsden Brook, Fort Fairfield, Maine Usa., Gregory J. Mcdonald

Electronic Theses and Dissertations

This study explores the sources and mechanisms of phosphorus (P) mobilization during base flow within the Amsden Brook watershed, Fort Fairfield, Maine, USA. Amsden Brook is an agriculturally dominated watershed drained by a spring-fed and perennial first- to second-order stream. We characterized the P concentrations within the watershed to investigate connections between soils, stream sediment, surface water, and groundwater. Waters were monitored monthly during the 2017 snow-free period for temperature, pH, dissolved oxygen, conductivity, soluble reactive P (SRP), total P, strong acid anions, strong base cations, dissolved organic carbon (DOC), Al, Fe, and Mn. Phosphorus speciation within soils and sediment …

Development And Thermodynamic Analysis Of An Integrated Mild/Partial Gasification Combined Cycle (Impgc) Under Green And Brown Field Conditions With And Without Carbon Capture, Henry A. Long Iii

University of New Orleans Theses and Dissertations

Coal is a very prominent energy source in the world, but it is environmentally unattractive due to its high sulfur and ash content as well as its alleged contribution towards climate change, but it is affordable, abundant, and has high energy content. Thus, utilizing coal in a cleaner and more efficient way has become necessary. One promising clean coal technology involves fully gasifying coal into synthesis gas, cleaning it, and feeding it into a high-efficiency combined cycle, such as an Integrated Gasification Combined Cycle (IGCC). Inspired by the recent success of warn gas cleanup (WGCU), mild and partial gasification are …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Side Chain Modifications To Improve Peptide Structure–Activity Relations, Neelam Lahankar

Seton Hall University Dissertations and Theses (ETDs)

While natural peptides, are ideal starting points for peptide-based drug design and development, they suffer from high conformational instability, which results in susceptibility to proteolytic degradation and poor bioavailability. Peptidomimetics in recent years has helped circumvent these shortcomings by improving the pharmacological properties of polypeptides. Peptidomimetics contain essential elements (pharmacophores) that mimic a natural peptide or protein in 3D space and retain the ability to interact with the biological target producing the same biological effect. In contrast, they offer conformationally restricted structures, potentially minimizing cross-target interactions, which leads to better transport properties through biologic membranes and resistance to immune responses. …

Kcnq1/Kcne1 Interaction In The Cardiac Iks Channel And Its Physiological Consequences, Jiajing Xu

McKelvey School of Engineering Theses & Dissertations

Dynamic conformational changes of ion channel proteins during activation gating determine their function as carriers of current. The relationship between these molecular movements and channel function over the physiological timescale of the action potential (AP) has not been fully established due to limitations of existing techniques. We constructed a library of possible cardiac IKs protein conformations and applied a combination of protein segmentation and energy linearization to study this relationship computationally. Simulations reproduced the effects of the beta-subunit (KCNE1) on the alpha-subunit (KCNQ1) dynamics and function, observed in experiments. Mechanistically, KCNE1 increased the probability of “visiting” conducting pore conformations on …

Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger

UNLV Theses, Dissertations, Professional Papers, and Capstones

X-ray induced damage is generally considered a nuisance, but in the field of Useful Hard X-ray Photochemistry we harness the highly ionizing and penetrating properties of hard X-rays (> 7 keV) to initiate novel photochemical decomposition and synthesis at ambient and extreme conditions. Preliminary experiments suggest that the energy of irradiating photons and the sample pressure play roles in determining the nature of X-ray induced damage. Here, we present the X-ray energy dependence of damage induced in strontium oxalate, strontium nitrate, and barium nitrate, as well as the pressure dependence of X-ray induced damage of strontium oxalate. Our results indicate …

Mechanisms For The Incorporation And Distribution Of Radionuclides In Near-Surface Fallout, Marc Alan Fitzgerald

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fallout is the radioactive glass formed from a mixture of vaporized anthropogenic materials with proximate environmental material. These glassy byproducts constitute a compositional record of environmental materials such as soil and vapor precursors that are responsible for chemical heterogeneity in the glasses. The work of this dissertation is to untangle these different sources of compositional heterogeneity, distinguishing low-abundance vaporized anthropogenic-rich material from natural compositions, in order examine soil behavior and chemical evolution during fallout formation. Unfortunately, mixing convolutes the multivariate elemental relationships in these melts due to overlapping element abundances that might distinguish different source materials and chemical behaviors, making …

Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp

Electronic Theses and Dissertations

Development of a photosensitizer that can work in both aerobic and anaerobic environments would increase the robustness of the cancer treatment known as photodynamic therapy. The development of a photosensitizer was first attempted by synthesizing a tin (IV) meso-tetra (4-pyridyl) porphyrin dichloride-tetrachlorobis (Bipy)₂ ruthenium (II) complex. The synthesize of the tin porphyrin was done by a method from literature and had a percent error of 31.58 and 37.31 when comparing the theoretical percentages of carbon (55.39) and nitrogen (12.92) meaning that photosensitizer was not synthesized.

The second type of chromophore that was studied was 1-nitropyrene do determine if it …

Modeling The Bioactivation And Subsequent Reactivity Of Drugs, Tyler Brian Hughes

Arts & Sciences Electronic Theses and Dissertations

Metabolism can convert drugs to harmful reactive metabolites that conjugate to DNA and off-target proteins. Reactive metabolites are a significant driver of both drug candidate attrition and withdrawal from the market of already approved drugs. Unfortunately, reactive metabolites are difficult to study in vivo, because they are transitory and generally do not circulate. Instead, this work computationally models both metabolism and reactivity. Using deep learning, predictive models were developed for the metabolic formation of quinones and epoxides, which together account for about half of known reactive metabolites. Additionally, an accurate model of DNA and protein reactivity was constructed, which predicts …

Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern

Arts & Sciences Electronic Theses and Dissertations

Positron emission tomography (PET) imaging utilizes drugs labeled with positron emitters to target and evaluate different biological processes occurring in the body. Tailoring medicine to the individual allows for higher quality of care with better diagnosis and treatment and is a key purpose for advancing research into developing new platforms for PET imaging agents. A PET nuclide of high interest for the development of these agents is 89Zr. This can be attributed to the long half-life of 3.27 days and low positron energy of 89Zr.

In this work, we developed a production method for 89Zr using Y sputtered coins that …

Anodic Cyclization Reaction: Manipulation Of Reaction Pathway And Efforts To Radical Cation And Radical Intermediate, Ruozhu Feng

Arts & Sciences Electronic Theses and Dissertations

In recent years, synthetic chemists have been expressing significant interest in electro-organic synthetic methods. This interest is being fueled by the existence of an increasing number of successful methods in the literature and the availability of new electrochemical equipment that removes the barrier to attempting an electrolysis reaction for the first time. Yet while these developments have fueled growth in some areas of electro-organic synthesis (the recycling of chemical catalysts for example), other areas remain underdeveloped. One such area is the exploration of reactions that can be triggered directly as an electrode surface without the use of any chemical reagent. …

Photophysical Characterization And Wavelength Tuning Of Natural And Synthetic Oxobacteriochlorins And Biohybrids, Don Hood

Arts & Sciences Electronic Theses and Dissertations

ABSTRACT OF THE DISSERTATION

Photophysical Characterization and Wavelength Tuning of Natural and Synthetic Oxobacteriochlorins and Biohybrids

By

Donald L. Hood

Doctor of Philosophy in Chemistry

Washington University in St. Louis, 2018

Dr. Dewey Holten, Chairperson

Herein is discussed the theoretical and practical unpinnings of photophysical behaviors and kinetic constants for tetrapyrrole macrocycles, to wit, porphyrins, chlorins, and bacteriochlorins. Understanding the characteristic photophysical response of tetrapyrroles to changes in environment or substituents is important to designing synthetic chromophores with tunable absorption wavelengths and for preparing useful biohybrids of natural photosynthetic light antennas combined with unnatural chromophores attached to the light antenna …

Mechanisms Of Calcium Phosphate Mineralization On Biological Interfaces And Their Engineering Applications, Doyoon Kim

McKelvey School of Engineering Theses & Dissertations

All living organisms utilize phosphorus (P) as an essential component of their cell membranes, DNA and RNA, and adenosine triphosphate. Bones, in addition to bearing loads, play an important role in balancing P levels in our bodies. In bones, a network of collagen templates and calcium phosphate (CaP) nanocrystals builds hierarchical levels, from nano- to macroscale. Within this architecture, the thermodynamic properties of CaP minerals are influential. Despite the importance of nucleation, growth, and crystallization in collagen structures for tissue development, little kinetic study of these processes has been conducted due to the limited in situ techniques for monitoring these …

Photo-Isomerizable Complementary Hydrogen Bond Arrays, Jeffrey S. Pleizier

Electronic Thesis and Dissertation Repository

The use of light as an external stimulus provides a non-invasive technique to induce large changes in physical and chemical properties of a substrate. The incorporation of a photochromic subunit into supramolecular polymeric systems therefore adds a potential "smart" quality for polymer manipulation. The azo moiety (-N=N-) is one of the most popular photochromic units as the trans to cis isomerization results in a large degree of spatial rearrangement. This present thesis exploits the azo group by its incorporation into complementary hydrogen bonded complexes. Hydrogen bonding acceptor groups attached to the periphery of the central azo photoswitch provided strong complexation …

Detection And Melting Of Surface-Bound Dna Using A Purely Electrochemical Approach, Denny Ho

Master's Theses

In this thesis, we demonstrate an electrochemical approach for monitoring the electric-field induced melting of surface-bound double-stranded DNA. The electrochemical routine involves repeated chronoamperometry pulses to melt the duplex and square wave voltammetry to monitor the extent of melting. We utilize a scanning potential and constant potential technique to generate melting curves and access the stability and kinetics of the DNA duplexes. Our method uses a mixed monolayer of thiol-modified DNA oligomers and mercaptohexanol on gold electrodes, are subsequently incubated with target DNA covalently modified with electroactive methylene blue. Under room temperature, 10 mM Tris, and optimized electrochemical parameters, DNA …

The Investigation Of The Chlorine Initiated Oxidation Of 2-Phenylethanol And Stability Of Superalkali Lithium Substituted Silyls., Adam Otten

Master's Theses

This thesis investigates the combustion potential of 2-phenylethanol and the superalkali properties of small lithium substituted silicon compounds. All combustion experiments were performed at the Advanced Light Source of Lawrence Berkeley National Laboratory at the Chemical Dynamics Beamline 9.0.2. The chlorine initiated oxidation of 2PE was investigated at 298 and 550 K using a multiplex photoionization mass spectrometer, coupled with the tunable vacuum ultraviolet radiation. Reaction products were identified using kinetic time traces and photoionization spectra.

Additionally, the stability of small superalkali silicon-lithium compounds has also been investigated. All structures and energetics were calculated using the CBS-QB3 composite method.

The …

Synthesis Of Doxorubicin-Based Prodrug And Activatable Mr Nanoprobe For The Imaging And Treatment Of Cancer, Bayan Dous

Electronic Theses & Dissertations

Magnetic Resonance Imaging (MRI) is increasingly being used as a diagnostic tool for cancer. We propose a novel molecular probe, Gadolinium-DTPA disulfide-bonded Doxorubicin (Gd-DTPA-SS-Doxo) encapsulated in iron oxide which could provide a dual modality for detecting malignant growth while simultaneously targeting treatment options. We first synthesized Gd-DTPA-SS-Doxo followed by encapsulation within the poly (acrylic acid) (PAA) coating of iron oxide nanoparticle (IONP), producing a nanoprobe (IO-Gd-DTPA-SS-Doxo) with quenched longitudinal spin lattice magnetic relaxation (T1). After receptor-mediated internalization, Gd-DTPA-SS-Doxo is released from the nanoprobe’s polymeric coating due to the acidic microenvironment of the tumor. When the molecular probe is subjected to …

Electropolymerization Of Polyaniline In The Presence Of Ferricyanide: Electrochemical, Spectroscopic And Gravimetric Studies, Lucas Marinelli

Master's Theses

In this work, ferricyanide-doped polyaniline (PANI) is electropolymerized by constant current and cyclic voltammetry (CV) measurements with simultaneous monitoring of mass changes using electrochemical quartz crystal microbalance (eQCM). Raman spectroscopy, Fourier transform infrared spectroscopy and CV measurements confirm the incorporation of the ferricyanide into the film and indicate modified electrical conductivity. UV-Vis absorbance spectroscopy and Raman spectroscopy confirm the conducting ‘emeraldine-salt’ state and confirm the presence of polarons, i.e. charge carriers.

The addition of ferricyanide during electropolymerization of the PANI film results in an increase of polymerization rate as confirmed using eQCM. A decrease in counter ion ingress/egress and an …

Combination Therapy: Parp Inhibitor Synergizes The Therapeutic Efficacy Of Doxorubicin In The Treatment Of Prostate Cancer, Momin Ansare

Electronic Theses & Dissertations

Men are most susceptible to prostate cancer in the United States. The general treatment options include surgery, hormone therapy, chemotherapy, and radiation therapy. But in recent days, the nanoformulation have shown promising applications in overcoming the drawbacks of the currently available treatment options. To complement, we tried to enhance the capability of the nanoparticle formulation by loading them with a novel drug combination for the treatment of prostate cancer. Herein, we synthesized folate conjugated iron oxide nanoparticles encapsulated with doxorubicin and olaparib for imaging and targeted treatment of prostate cancer. Both drugs are approved by FDA for clinical cancer treatment. …

Corrosion Dynamics Of Carbon Steel In Used Fuel Container Environments, Dan Guo

Electronic Thesis and Dissertation Repository

The current Canadian used nuclear fuel container (UFC) design uses a pressure‑grade carbon steel (CS) vessel with its outer surface coated with a thin layer of copper. One concern regarding the structural integrity of the UFC design is the potential internal corrosion of the CS vessel. Moisture trapped inside a UFC could condense within the gap between the hemispherical head and the cylindrical body of the vessel. The internal UFC environment will be exposed to a continuous flux of ionizing radiation arising from the decay of radionuclides trapped in the used UO₂ fuel matrix.

This thesis research project investigates …

Nonlinear Optical Characterization Of Solids, Alex Farnsworth

Undergraduate Honors Theses

Vibrational Sum Frequency Generation (VSFG) and the similar Second Harmonic Generation (SHG) are both classified as nonlinear optical phenomena, with the hallmark trait being that the input and output frequencies are different. Both of these systems are remarkable tools due to their surface specific nature. Still, there is much that is not known about the response from these systems, especially the nonresonant SFG response. We have worked to better understand SFG signal, specifically the nonresonant temporal profile. We have also collected results that call into question some underlying assumptions about time-based suppression methods when working with single crystal substrates.

As …

Synthesis And Integration Of Oligoviologens Into Hydrogel Actuators, Kevin Liles

Arts & Sciences Electronic Theses and Dissertations

Interest in the development of soft-material artificial molecular muscles has inspired scientists to pursue novel stimuli-responsive systems capable of undergoing change in the physical and mechanical properties of a material in response to external stimuli. This interest has been driven primarily by advances, or the desire for advances, in fields such as soft robotics, microfluidics, and bio-compatible drug-delivery systems. In this work, redox-responsive viologens and their ability to form stable radical-cation complexes were evaluated as a method of actuation in stimuli-responsive materials, specifically hydrogels.

First, a brief overview of hydrogel actuators is covered, with some examples given of the broad …

Assessing Biofiltration Without Ozonation For Removal Of Trihalomethane Precursors In Drinking Water At The Beaver Water District Drinking Water Treatment Plant, Sana Ajaz

Graduate Theses and Dissertations

Biofiltration without pre-ozonation has the capability to remove natural organic matter (NOM) fractions that serve as precursors of disinfection byproducts (DBPs), which include the four regulated trihalomethanes (THMs) and dichloroacetonitrile (DCAN). Rapid small-scale column tests (RSSCTs) and Pilot Plant filters operated at empty-bed contact times (EBCTs) of 4, 8, and 16 minutes were used to evaluate the performance of nutrient-amended (free ammonia and phosphorus) biofiltration for THM and DCAN precursor removal, as measured using formation potential (FP) tests. NOM surrogates – which include dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA254) and fluorescence-PARAFAC components – were measured weekly throughout the …

Diamond Intracrystalline Stable Isotope Chemical Image Analysis By Time-Of-Flight Secondary Ionization Mass Spectrometery, Tyler J. Sundell

MSU Graduate Theses

The chemical resistance of diamond allows in-situ study of the diamond source regions. For a majority of gem quality diamonds, this source region is the sublithospheric mantle keel of a cratonic nuclei. Through analysis of stable isotopes, radiogenic isotopes and trace elements, diamond geochemical analyses can define chemical fluxes in the mantle keel. However, such studies require multiple methodologies for each chemical suite, high spatial resolution and analytical precision. Here, I evaluate Time-of-Flight Secondary Ionization Mass Spectrometer (ToF-SIMS) as an alternative method for diamond geochemical analyses. ToF-SIMS analysis can perform in cation and anion mode to measure the entire periodic …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …

Effect Of Network Structure On Free Volume And Gas Transport Properties Of Thiol-Ene And Epoxy-Amine Networks, Ramesh Krishnan Ramakrishnan

Dissertations

Network parameters such as cross-link density or intermolecular interactions were used as effective parameters to control polymer chain packing or free volume and thereby control the mass transport properties of networks.

A series of polyethylene glycol (PEG) based thiol-ene elastomeric networks having a broad range of molecular weight between cross-links, M_c, (inverse of cross-link density) was prepared. The specific volume of the networks was studied as a function of temperature and pressure using high pressure dilatometry, and the obtained PVT data was fit using Simha-Somcynsky equation of state (S-S eos) analysis. Fractional free volume, quantified through S-S eos …

Structure-Property Relationships Of Solvent-Cast Organic Thin Films For Model Corrosion Control Coatings, Austin Maples

Dissertations

This dissertation aimed at answering several fundamental questions, specifically: 1) What is the effect of scribing parameters on visual corrosion assessments? 2) What role do molecular weight, residual solvent, and polymer composition have on morphological changes in organic thin films? 3) What alternatives to visual assessments could be implemented to better understand and detect corrosion before macroscopic failure? This research definitively proved that scribes can vary in type and dimensions, and yet are still comparable if the scribe dimensions before exposure are known. Furthermore, it demonstrated that solvents common to a variety of coating industries could become trapped within the …