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Investigating Ionic Current Rectification As A Means Of Controllable Drug Delivery Using Silica Nanoparticles And Nano Porous Membranes, Katie L. Nolan 2022 Georgia Southern University

Investigating Ionic Current Rectification As A Means Of Controllable Drug Delivery Using Silica Nanoparticles And Nano Porous Membranes, Katie L. Nolan

Honors College Theses

This project investigates a novel ionic current rectification (ICR) phenomenon created by the opening and closing of nanopores by charged silica nanoparticles (SNPs) under electrophoretic flow. This voltage-controlled opening and closing of the pores can be exploited to allow delivery of nicotine through the pores at programmable intervals. The ICR phenomenon was thoroughly investigated by varying pH, buffer concentration, SNP concentration, and applied voltage range. The mechanism was also verified by testing with a 2-, 3-, and 5-electrode system. Potential cake layer formation was demonstrated in a longer ICR test, and the implications of this on the drug delivery mechanism …


Development Of A Chromatographic Method To Authenticate Aspirin Brands, Megan Guetzloff 2022 South Dakota State University

Development Of A Chromatographic Method To Authenticate Aspirin Brands, Megan Guetzloff

Electronic Theses and Dissertations

Counterfeit pharmaceuticals pose a threat to society that can include inaccurate amounts of the active pharmaceutical ingredient (API), no API, or containing off-target compounds. For example, there are many recent examples of counterfeit pharmaceuticals containing potentially lethal doses (> 2 mg) of fentanyl (i.e., a synthetic opioid). Current measures to combat illicit pharmaceuticals (e.g., unique packaging and product serialization) have merit, however with evolved technologies, counterfeiters can relatively easily simulate these measures and continue to distribute illicit pharmaceuticals. The only accurate way to definitively determine that a suspected counterfeit is, in fact, counterfeit is advanced chemical analysis. However, current methods …


Influence Of Dissolved Organic Matter On Phosphate Interactions With Hydrous Ferric Oxides, Alaa Hasan Alsherbi 2022 Wilfrid Laurier University

Influence Of Dissolved Organic Matter On Phosphate Interactions With Hydrous Ferric Oxides, Alaa Hasan Alsherbi

Theses and Dissertations (Comprehensive)

Phosphorus, iron oxides, and dissolved organic matter (DOM) are components present in all aquatic systems. Excess amounts of phosphorus in aquatic systems have the potential for toxic effects, in particular, contributing to eutrophication. Most of the previous studies performed looked at the surface complexation of inorganic phosphate anions (P) to mineral surfaces such as hydrous ferric oxide (HFO). However, the role of DOM on the interactions between HFO and P is unknown. This study investigates the influence of DOM on the surface complexation of P onto HFO surfaces. Moreover, this study looks at the possibility of cation bridging formation (Ca …


Analysis Of The Light Responsive Azobenzene Peptide Nucleic Acid Duplexes, Kat Nguyen 2022 Georgia Southern University

Analysis Of The Light Responsive Azobenzene Peptide Nucleic Acid Duplexes, Kat Nguyen

Honors College Theses

Peptide nucleic acids (PNAs) are oligonucleotide analogues in which the sugar-phosphate backbone has been replaced by a pseudopeptide skeleton. Since PNAs use the natural nucleobases (Adenine, Thymine, Cytosine, Uracil, and Guanine) found in either DNA and/or RNA, they are able to hybridize according to Watson-Crick base-pairing to form duplexes. PNA is a promising therapeutic agent because they can function as antigene or antisense chemical agents. To further enhance their utility, we aim to incorporate a photoswitchable moiety using azobenzene. Here, we report the results of the synthesis and purification of a photoswitchable 11 mer PNA along with initial characterization efforts.


Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott 2022 West Virginia University

Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott

Graduate Theses, Dissertations, and Problem Reports

Forensic science relies on the use of multiple techniques in the assessment of evidence to increase the accuracy and reliability of the results. However, with the rapidly changing drug landscape due to the introduction of novel psychoactive substances, many traditional screening methods are no longer sensitive or selective enough for use. Additionally, many screening methods such as chemical color tests are prone to false positive and negative results and are subjective. Therefore, the goal of this dissertation was to develop a novel analytical scheme that can provide a more efficient, rapid, and sensitive method that will facilitate adoption in the …


Trends In Biomedical Analysis Of Red Blood Cells – Raman Spectroscopy Against Other Spectroscopic, Microscopic And Classical Techniques, Jakub Dybas, Fatih Celal Alcicek, Aleksandra Wajda, Magdalena Kaczmarska, Anna Zimna, Katarzyna Bulat, Aneta Blat, Tetiana Stepanenko, Tasnim Mohaissen, Ewa Szczesny-Malysiak, David Perez-Guaita, Bayden R. Wood, Katarzyna Maria Marzec 2022 Jagiellonian University Cracow

Trends In Biomedical Analysis Of Red Blood Cells – Raman Spectroscopy Against Other Spectroscopic, Microscopic And Classical Techniques, Jakub Dybas, Fatih Celal Alcicek, Aleksandra Wajda, Magdalena Kaczmarska, Anna Zimna, Katarzyna Bulat, Aneta Blat, Tetiana Stepanenko, Tasnim Mohaissen, Ewa Szczesny-Malysiak, David Perez-Guaita, Bayden R. Wood, Katarzyna Maria Marzec

Articles

Application of modern and innovative spectroscopic and microscopic approaches to biomedical analysis opens new horizons and sheds new light on many unexplored scientific territories. In this review, we critically summarize up-to-date Raman-based methodologies for red blood cells (RBCs) analysis used in biology and medicine, and compare them with both classical, as well as other spectroscopic and microscopic approaches. The main emphasis is placed on the advantages, disadvantages and capabilities of each technique for detection of RBC deteriorations and RBC-related diseases. Although currently used classical techniques of medical analysts serve as a gold standard for clinicians in diagnosis of erythropathies, they …


Electrochemistry Of Bubbles: Developing New Sensors, Promoting Gas Evolution Reactions, And Extraction Of Rare Earth Elements, Ruchiranga R. Ranaweera 2022 Wayne State University

Electrochemistry Of Bubbles: Developing New Sensors, Promoting Gas Evolution Reactions, And Extraction Of Rare Earth Elements, Ruchiranga R. Ranaweera

Wayne State University Dissertations

This dissertation presents new analytical, electrocatalysis, and separation strategies that utilize bubble behaviors in different electrochemical systems. The first part of this dissertation focuses on the method development for PFAS preconcentration and detection. First, we present the bubble-nucleation-based electrochemical method for the selective and sensitive detection of surfactants. Our method utilizes the high surface activity of surfactant analytes to affect the electrochemical bubble nucleation and then transduces the change in nucleation condition to an electrochemical signal for determining the surfactant concentration. Using this method, we demonstrate the quantitation of perfluorinated surfactants in water, a group of emerging environmental contaminants, with …


Electrochemical And Mass Spectrometry Methods For Identification Of Gunshot Residues (Gsr) In Forensic Investigations, Kourtney A. Dalzell 2022 West Virginia University

Electrochemical And Mass Spectrometry Methods For Identification Of Gunshot Residues (Gsr) In Forensic Investigations, Kourtney A. Dalzell

Graduate Theses, Dissertations, and Problem Reports

Gun violence continues to be one of most significant challenges straining the USA society causing thousands of human lives lost every year. In 2020 alone, firearm-related incidents including homicide, accidents, and suicides, reached a staggering number of over 43,000.1,2 With the increase in these types of incidents, several service areas in crime laboratories are heavily impacted by the number of cases run on a yearly basis. These include firearm examinations, gunshot residue (GSR) analysis, bullet hole identification, and shooting distance determination, which are crucial to support a criminal investigation and, overall, the justice system in our country. These areas …


Heterogeneous Oxidation Of Multi-Component Aqueous Organic Aerosols: The Effect Of Transport Phenomena And Reaction Compartment On Reaction Kinetics., Tadini wenyika Masaya 2022 West Virginia University

Heterogeneous Oxidation Of Multi-Component Aqueous Organic Aerosols: The Effect Of Transport Phenomena And Reaction Compartment On Reaction Kinetics., Tadini Wenyika Masaya

Graduate Theses, Dissertations, and Problem Reports

The surface-bulk partitioning of small organic molecules in aqueous droplets was investigated using molecular dynamics. The air-particle interface was modeled using a 80-Å cubic water box containing series of organic molecules and surrounded by gaseous OH radicals. The properties of the organic solutes within the interface and the water-bulk were examined at a molecular-level using density profiles and radial pair distribution functions. Molecules containing only polar functional groups such as urea and glucose are found predominantly in the water bulk, forming an exclusion layer near the water surface. Substitution of a single polar group by an alkyl group in sugars …


Disease Biomarker Discovery And Fungal Metabolites Extraction Protocol Optimization Using Gcms Based Metabolomics, Chathuri Udeshika Gamlath Mohottige 2021 Mississippi State University

Disease Biomarker Discovery And Fungal Metabolites Extraction Protocol Optimization Using Gcms Based Metabolomics, Chathuri Udeshika Gamlath Mohottige

Theses and Dissertations

Metabolomics is a powerful science that can be applied for the discovery of disease biomarkers, and investigation of altered metabolomes due to abiotic and biotic perturbations. This dissertation is focused on untargeted metabolomic applications to investigate fungal metabolite alterations associated with pathogenicity, fungal disease propagations, and symbiosis. This dissertation employs qualitative analysis of metabolite mixtures using HS-SPME coupled GC-MS and TMS derivatization followed by GC-MS analytical platforms. In the first study, we discovered a biomarker combination to diagnose fungal soft tissue disease in sweet potato at an early stage of disease propagation. We used an HS-SPME GC-MS untargeted metabolomics workflow …


Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva 2021 Mississippi State University

Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva

Theses and Dissertations

Mass spectrometry (MS) has become a widely used technique for the characterization of a wide range of substances in diverse fields. The selection of appropriate ionization techniques, source parameters, charge carriers based on the analyte’s polarity is essential in MS as only the ions are detected. When using a soft ionization technique, single stage-MS at best provides only chemical composition; thus, tandem MS is needed to determine structural information and dissociation pathways. This dissertation focuses on the characterization of various small molecules and ions using different ionization techniques, charge carriers, and collision-induced dissociation (CID).

In Chapter II, commercially available ionic …


Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri 2021 University of Tennessee, Knoxville

Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri

Doctoral Dissertations

High-entropy materials (HEMs) have emerged as a new class of multi-principal-element materials with great technological prospects. As a unique class of concentrated solid-solution materials, HEMs, formed on the premise of incorporating five or more principal elements into a single crystalline phase, provide an excellent opportunity to access superior catalytic materials ‘hiding’ in the unexplored central regions of a multicomponent phase space of higher orders.

However, the fabrication of HEMs is energy-intensive, typically requiring extreme temperatures and/or pressures under which agglomeration of particles occurs with a commensurate decrease in surface area. For most catalytic applications, non-agglomerated particles with high surface areas …


Analytical Considerations And Methods For Comprehensive Analysis Of Bacterial Phospholipidomics Using Hilic-Ms/Ms, David Thomas Reeves 2021 University of Tennessee, Knoxville

Analytical Considerations And Methods For Comprehensive Analysis Of Bacterial Phospholipidomics Using Hilic-Ms/Ms, David Thomas Reeves

Doctoral Dissertations

Omics technologies have rapidly evolved over the last half century through vast improvements in efficient extraction methodologies, advances in instrumentation for data collection, and a wide assortment of informatics tools to help deconvolute sample data sets. However, there are still untapped pools of molecules that warrant further analytical attention. As the frontline defense of the cell against exterior influences, the phospholipid membrane is key in structure, defense, and signaling, but current omics studies are only just now catching up to the potential hidden within cellular lipid profiles. Examination of shifts in phospholipid speciation and character could provide researchers with a …


Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser 2021 University of Tennessee, Knoxville

Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser

Doctoral Dissertations

Just as humans communicate with other humans, the cells in our bodies communicate with each other through various, often complex, mechanisms. Cell-to-cell transmission of small molecules, lipids, proteins, peptides, or nucleic acids can be mediated by extracellular lipid vesicles called exosomes. Exosomes have been found to play a role in the delivery of regulatory molecules from one cell to another, serving as a universal communication mechanism. Currently, there is an emerging focus on characterizing exosome communication dynamics. Understanding exosome mechanisms of cell-to-cell communication requires accurate measurements of the spatiotemporal and chemical dynamics of exosome secretion. No current analytical approach offers …


Determining The Presence Of Biological Fluids In Peruvian Mummy Cloths Using The Liquid Chromatography Quadruple Time Of Flight Instrument, Tim Perksen, Joshua Sebree Ph.D. 2021 University of Northern Iowa

Determining The Presence Of Biological Fluids In Peruvian Mummy Cloths Using The Liquid Chromatography Quadruple Time Of Flight Instrument, Tim Perksen, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes used and the results of analyzing the cloth from Peruvian mummies for the presence of biological fluids.


Identification Of Natural Dyes In Ancient Peruvian Mummy Cloths Using Lc/Ms/Ms, Shailah Mathews, Joshua Sebree Ph.D. 2021 University of Northern Iowa

Identification Of Natural Dyes In Ancient Peruvian Mummy Cloths Using Lc/Ms/Ms, Shailah Mathews, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes used and the results of analyzing the natural dyes used on cloth from Peruvian mummies.


Detecting Oceanic Salt In Peruvian Mummy Cloths Using Scanning Electron Microscopy, Alexis Wirtz, Joshua Sebree Ph.D. 2021 University of Northern Iowa

Detecting Oceanic Salt In Peruvian Mummy Cloths Using Scanning Electron Microscopy, Alexis Wirtz, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes and the results of analyzing cloth from Peruvian mummies for the presence of ocean salts.


Bioactivity Assessment Of Veratrum Californicum Alkaloids, Madison Dirks 2021 Boise State University

Bioactivity Assessment Of Veratrum Californicum Alkaloids, Madison Dirks

Boise State University Theses and Dissertations

The native Idaho plant Veratrum californicum is known to contain steroidal alkaloids that function as inhibitors of hedgehog signaling, a pathway utilized for the growth and differentiation of cells as well as proper tissue development. Veratrum californicum was originally noticed when pregnant ewes consumed the plant and later gave birth to lambs with craniofacial mutations such as a cyclopean eyes. These malformations were caused by the plant’s steroidal alkaloid cyclopamine blocking the hedgehog signaling pathway. This same pathway is used by more than 20 types of cancer for multiplication of cells. Additional alkaloids have been found in Veratrum californicum, …


Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon 2021 University of Tennessee, Knoxville

Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon

Doctoral Dissertations

As technology advances to harness new energies and to create new cures, the sophistication of analysis grows not only in depth but in efficiency. Total internal reflection (TIR) has been coupled to microscopy leveraging its unique optical phenomenon on a breadth of topics. In this dissertation, the work presented will show how TIR was applied in two different instrumental analyses to evaluate two unique and complex systems. The first project features TIR paired with the transient absorption microscopy (TAM), a nonlinear optical technique, to gauge solvent mixing and diffusion in microreactors. Microreactors gained acclaim for their ability to produce high …


Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba 2021 Chapman University

Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba

Student Scholar Symposium Abstracts and Posters

Forensic analysis of suspected narcotics is often dangerous as the substances’ composition is unknown. Many techniques for drug identification require handling of the substance outside of its packaging, which can expose the analyst to potentially harmful chemicals. The TruNarc Handheld Narcotics Analyzer is a portable Raman spectroscopy device that is non-destructive of evidence and can be used to screen drugs through simple packaging to minimize the risk of exposure. The Orange County Crime Lab (OCCL) is testing the limits of this device to determine if it can be used to screen new evidence within the Seized Drugs Lab. The OCCL …


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