Physical Sciences and Mathematics Commons^™

Sharprazor: Automatic Removal Of Hair And Ruler Marks From Dermoscopy Images, Reda Kasmi, Jason Hagerty, Reagan Harris Young, Norsang Lama, Januka Nepal, Jessica Miinch, William V. Stoecker, R. Joe Stanley

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Background: The removal of hair and ruler marks is critical in handcrafted image analysis of dermoscopic skin lesions. No other dermoscopic artifacts cause more problems in segmentation and structure detection. Purpose: The aim of the work is to detect both white and black hair, artifacts and finally inpaint correctly the image. Method: We introduce a new algorithm: SharpRazor, to detect hair and ruler marks and remove them from the image. Our multiple-filter approach detects hairs of varying widths within varying backgrounds, while avoiding detection of vessels and bubbles. The proposed algorithm utilizes grayscale plane modification, hair enhancement, segmentation using tri-directional …

Exploring Protein Conformations And Functions Through Molecular Dynamics Simulations And Machine Learning, Hao Tian

Chemistry Theses and Dissertations

Proteins are essential biomacromolecules that perform a variety of critical functions in living organisms. The tertiary structure of a protein plays a crucial role in its biological activity as it determines how the protein interacts with other molecules. Consequently, understanding protein conformation and function is an important area of research with implications in medicine, biotechnology, and other fields.

The first part of this dissertation focuses on protein allostery, a process by which proteins transmit perturbations caused by binding at one site to a distal site, thereby regulating activity. With the development of computational methods like molecular dynamics simulations and machine …

Modeling Excited State Processes In Molecular Aggregates By Constructing An Adaptive Basis For The Hierarchy Of Pure States, Leonel Varvelo

Chemistry Theses and Dissertations

Simulating excitation energy transfer (EET) in molecular materials is of crucial importance for the development of and understanding of materials such as organic photovoltaics and photosynthetic systems and further development of novel materials. The Hierarchy of Pure States (HOPS) is an exact framework for the time evolution of an open quantum system in which a hierarchy of stochastic wave functions are propagated in time. The adaptive HOPS (adHOPS) method achieves size-invariant scaling with the number of simulated molecules for sufficiently large aggregates by using an adaptive basis that moves with the excitation through the material. To demonstrate the power of …

Synthesis And Characterization Of Terbium(Iii) Complexes: Can We Manipulate The Emission Signature?, Ryan Gagnon

Belmont University Research Symposium (BURS)

Successful Lewis acid/base reactions of terbium(III) nitrate with 2,2’-bipyrdine (22’bpy), 1,10-phenanthroline (phen), and 2,6-pyridine dimethanol (pydm) have yielded the products: Tb(22’bpy)₂(NO₃)₃, Tb(phen)₂(NO₃)_3, and [Tb(pydm)₃](NO₃)₃, respectively. In accord with the well-known antenna-effect, the absorption spectrum of each complex is similar to the spectrum of the free ligand, while the emission spectrum of the complex is identical for the free terbium(III) ion. In contrast, the substitution of a ligand containing a third-row nonmetal strategically placed near the terbium may force interaction between the 3p nonmetal …

Rage Inhibitors In Neurodegenerative Diseases, V. Prakash Reddy, Puspa Aryal, Pallavi Soni

Chemistry Faculty Research & Creative Works

Nonenzymatic Reactions of Reducing Sugars with Primary Amino Groups of Amino Acids, Proteins, and Nucleic Acids, Followed by Oxidative Degradations Would Lead to the Formation of Advanced Glycation Endproducts (AGEs). the AGEs Exert Multifactorial Effects on Cell Damage Leading to the Onset of Neurological Disorders. the Interaction of AGEs with the Receptors for Advanced Glycation Endproducts (RAGE) Contribute to the Activation of Intracellular Signaling and the Expression of the Pro-Inflammatory Transcription Factors and Various Inflammatory Cytokines. This Inflammatory Signaling Cascade is Associated with Various Neurological Diseases, Including Alzheimer's Disease (AD), Secondary Effects of Traumatic Brain Injury (TBI), Amyotrophic Lateral Sclerosis …

The Coastal Monitor: Vol. 10 No. 1, John Tanacredi Ph.D.

The Coastal Monitor

New Year’s Day has always been, for me, a time to reflect and project into the near future. Nature’s influence on us all certainly tops my listing with several environmental concerns. For example, the frequency and intensity of hurricanes to Long Island. A decade has passed since Superstorm Sandy re-opened the “Old Inlet” on Long Island which now has mostly naturally closed. So, the new year immediately prompts me to assess the previous year’s Hurricane Ian, a Category 4 system, with winds exceeding 150 mph, which had considerable impact in Florida, and then proceeded north resulting in over 2 inches …

Stem Club, Rohan Tatineni, Kevin Prososki

Honors Expanded Learning Clubs

The goal of STEM club is to teach the students various basic scientific principles and relate them to experiments and the real world. In addition, the scientific method will be taught and be a main focus of the club along with the engineering design process.

Synthesis And Characterization Of Hydroxy-Functionalized Copper Indium Disulfide Quantum Dots, Julia Schexnayder

WWU Honors College Senior Projects

Quantum dots offer tunable electronic and optical properties due to the quantum confinement effect, making them desirable for various applications. However, their native hydrophobic form requires surface chemistry modification for certain applications. This research explores the method of ligand exchange using 11-mercapto-1-undecanol for improving the stability of copper indium disulfide (CIS) quantum dot (QD) nanoparticles in polar environments. The effects of this ligand exchange on QD chemical composition, optical properties, hydroxy-reactivity, and hydrodynamic radius are characterized. Analysis of characterization results indicates successful surface modification through hydroxyfunctionalization, as confirmed by 1H-NMR and IR spectroscopy. The desired optical properties of the QDs …

Investigation Of Cofactor Activities Of Endothelial Microparticle- Thrombomodulin With Liposomal Surrogate, Valentinas Gruzdys, Lin Wang, Dan Wang, Rachel Huang, Xue-Long Sun

Chemistry Faculty Publications

Thrombomodulin (TM) is a type I transmembrane glycoprotein mainly expressed on the endothelial cells, where it binds thrombin to form the thrombin-TM complex that can activate protein C and thrombin-activable fibrinolysis inhibitor (TAFI) and induce anticoagulant and anti-fibrinolytic reactions, respec-tively. Cell activation and injury often sheds microparticles that contain membrane TM, which circulate in biofluids like blood. However, the biological function of circulating microparticle-TM is still unknown even though it has been recognized as a biomarker of endothelial cell injury and damage. In comparison with cell membrane, different phospholipids are exposed on the microparticle surface due to cell membrane "flip-flop"upon …

Using Capillary Electrophoresis To Quantify Competitive Binding Of Adsorbates To Silver Nanoparticles, Christopher D. Chung , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are increasingly used commercially and medically due to their antimicrobial and antibacterial properties. With increased use comes increased release of AgNPs into the environment, and once released, AgNPs can form coronas with molecules ranging from biomolecules to proteins to natural organic matter (NOM). The molecules in the corona adsorb to the surface of the AgNPs, drastically altering their innate properties such as cytotoxicity and binding behavior. In this study, we characterize and quantify model AgNP-adsorbate systems by obtaining their relevant reaction parameters through three different affordable analytical techniques, including dynamic light scattering (DLS), UV-vis spectroscopy, and capillary …

Using Caulobacter Crescentus As A Model To Probe The Environmental Reactivity Of Silver Nanoparticles, Madeline M. Farber , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are an increasingly common environmental pollutant with antimicrobial and antibacterial properties. The elucidation of their interaction with cellular membranes and subsequent mechanisms of toxicity are critical areas of research that need to be better understood in order to manage potential adverse environmental effects. This work investigates the interaction of AgNPs with large unilamellar vesicles (LUVs) as a model membrane system. Similar studies conducted by others in this field have largely been conducted with uncoated AgNPs, ignoring the effect of environmental conditions on the formation of an eco-corona on AgNPs. Thus, in this study, the spent medium (SM) …

Master Equation Modeling Of Prompt Dissociation Kinetics For Isoprene Derived Criegee Intermediates, Rory R. Schmidt , '23

Senior Theses, Projects, and Awards

Isoprene ozonolysis is a major atmospheric producer of atmospheric oxidizers and aerosols. This complex reaction pathway forms an exothermic cascade, where constant competition between bimolecular sinks, unimolecular isomerizations, and collisional relaxation dictate reactivity. This work focuses on two isoprene derived Criegee intermediates, methacrolein oxide (MACR oxide) and formaldehyde oxide (FO). While the potential energy surface of FO is well understood, the reactivity of energetically excited FO has not been explored in detail. MACR oxide isomerization and primary products have been adequately characterized and explored computationally and experimentally, but the potential energy surface beyond isopropenyl dioxirane has not received the same …

Biophysical And X-Ray Crystallographic Characterizations On Complexes Of G-Quadruplexes With Small-Molecule Ligands, Ming Ye , '23

Senior Theses, Projects, and Awards

DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets for anticancer and antiviral drugs. Therefore, investigating the interaction between GQs and small-molecule ligands is important.

This thesis work surveyed the DNA-ligand interactions of over 20 GQ-ligand complexes via biophysical and X-ray crystallographic methods. Two sets of GQ-ligand complexes were characterized in detail. One set is a group of purine-only sequences, named GA, with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). The other set is a human telomeric sequence, Tel22, with …

Method Design For Separation Of Non-Canonical Dna Structures Via Capillary Electrophoresis, Erin V. Chen , '23

Senior Theses, Projects, and Awards

G-quadruplex DNA structures are highly relevant subjects of biochemical study, implicated in human diseases and cancer. Conventional methods for G-quadruplex DNA structure separation are time-consuming, environmentally unfriendly, and low throughput. Thus, there is a pressing need for alternative methods of separation to be developed for G-quadruplex DNAs. Here we present work in designing a separation method using the capillary electrophoresis instrument. Capillary electrophoresis is a highly automated, reusable, and quantitative technique that separates analytes based on their size and charge. A capillary method for G-quadruplex separation would be a valuable analytical tool to supplement the biophysical methods available by addressing …

Development Of Innovative Multi-Drug Approaches To Counteract Illicit Drug Abuse In The Uae Population, Manal Ali Alhefeiti

Dissertations

The abuse of addictive substances is on the rise in the United Arab Emirates (UAE) population. Consequently, the UAE government spends about Dhs 5.5 billion annually on the rehabilitation of drug addicts. Blood, urine, and hair tests can reveal signs of sporadic or chronic drug use. Given the list of banned chemicals in the UAE, our main objective in this work was to develop a novel analytical method to identify and measure banned substances, especially prescription and over-the-counter drugs in the UAE. We developed and validated a rapid, sensitive and reliable liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) approach for the targeted …

Synthesis And Characterization Of Some Disubstituted Cyclopentadienyl Rhenium Complexes As Potential Candidates In Semiconductive Materials, Chloe Vernon

Senior Honors Theses

Since 2000, when the Nobel Prize in Chemistry as awarded for conductive polymer research few studies have been performed concerning the conductive capabilities of discrete organometallic compounds. For this project, organometallic compounds were formed specifically with a transition metal included in the structure. Through oxidation and reduction reactions, the variation in the electrical conductivity could allow for an analysis of whether this unique structure would allow for tunability. The goal of this research was to begin with aromatic substituted fulvenes and perform various multistep synthesis processes, utilizing thallium salt intermediates, to produce several disubstituted cyclopentadienyl rhenium complexes. In this project, …

Molecular Cluster Complex Of High-Valence Chromium Selenide Carbonyl As Effective Electrocatalyst For Water Oxidation, Ibrahim Munkaila Abdullahi, Manashi Nath

Chemistry Faculty Research & Creative Works

Developing Simple, Affordable, and Environmentally Friendly Water Oxidation Electrocatalysts with High Intrinsic Activity and Low overpotential Continues to Be an Area of Intense Research. in This Article, a Trichromium Diselenide Carbonyl Cluster Complex (Et₄N)₂[Se₂Cr₃(CO)₁₀], with a Unique Bonding Structure Comprising Bridging Se Groups, Has Been Identified as a Promising Electrocatalyst for Oxygen Evolution Reaction (OER). This Carbonyl Cluster Exhibits a Promising overpotential of 310 MV and a Low Tafel Slope of 82.0 MV Dec⁻¹ at 10 MAcm⁻², with Superior Durability in an Alkaline Medium, for a Prolonged …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Paul C. Seth , '23

Senior Theses, Projects, and Awards

G-quadruplex (GQ) and i-motif (iM) non-canonical DNA structures can be formed by G- and C-rich sequences within the genome, respectively. GQ and iM DNA play important roles in different biological processes and are promising therapeutic targets. Recently, the first left-handed GQ (LHGQ) was discovered and much remains to be learned about the structure and function of LHGQ DNA.

In this thesis, we investigate the biophysical and structural behavior of two LHGQ-forming sequences from the human genome, from the Human Solute Carrier 1 (SLC) and nuclear receptor binding SET domain (NSD) genes. We found that flanking bases play an important role …

Diffractive Imaging Of Laser Induced Molecular Reactions With Kiloelectron-Volt Ultrafast Electron Diffraction, Yanwei Xiong

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Capturing the structural changes during a molecular reaction with ultrafast electron diffraction (UED) requires a high spatiotemporal resolution and sufficiently high signal-to-noise to record the signals with high fidelity. In this dissertation, I have focused on the development of a tabletop gas phase keV-UED setup with a femtosecond temporal resolution. A DC electron gun was employed to generate electron pulses with a high repetition rate of 5 kHz. The space charge effect in the electron pulse was ameliorated by compressing the 90 keV electron pulse longitudinally with a time varying electric field in an RF cavity. The velocity mismatch between …

Exploring New Techniques For Precision Deuteration Of Alkenes And Alkynes, Zoua Pa Vang

Dissertations (1934 -)

Deuterium labeled compounds are often utilized in chemical research as internal standards in mass spectrometry, to study reaction mechanisms and in the pharmaceutical industry to slow the rate of metabolism. With the increase interest for deuterium labeled molecules, there is a renewed interest in selective methods for the installation of deuterium atoms into small organic molecules. However, current methods to incorporate deuterium atoms into organic molecules can lead to isotopic mixtures such as isotopologues and isotopomers. These isotopic species are indistinguishable due to their similar physical properties, leading to inseparable products by common purification techniques. Furthermore, common spectroscopic techniques to …

Expanding Tailorable Nanomaterial Synthesis With Persistent Micelle Templates, Eric R. Williams

Theses and Dissertations

The control of block polymer micelle dimensions while in solution is critical for a range of emerging applications in diverse fields from drug delivery and nanoreactors to use as sacrificial templates for porous nanomaterials. When under kinetic control, micelles will maintain a constant average size and thus aggregation number (N_agg) through the suppression of chain exchange mechanisms. Such kinetic control effectively enables the decoupling of micelle dimensions from solution conditions. In other words, kinetically trapped micelles can resist reorganizations brough about by e.g., the addition of metal nanoparticles. However, such micelles are traditionally governed by a fickle �� …

The Love Collection Of Chinese Wall Paintings, Donglin Chen

Senior Theses and Projects

The Chinese Fresco Painting (accession #1951.230) at the Wadsworth Atheneum Museum of Art is a problematic work. The museum registration document showed that this wall painting is thought to have been painted during the Ming dynasty, ruling from 1368 to 1644. It may depict the Goddess of Sons and Grandsons, Zisun Niangniang. However, this is unprovenanced and unresearched. In this paper, connoisseurship analysis and scientific examination of the painting are carried out to elucidate the mystery of this Chinese mural. This study attempted to confirm the Ming Dynasty dating of this painting by demonstrating stylistic affinities between it and other …

Using Cyclic-Step Chronopotentiometry To Explore Electron Mobility In Dye-Sensitized Solar Cells, Jasmine Hopson, Ian Mcneil

Honors Projects

In this project, we are making dye-sensitized solar cells using titanium dioxide and the dye from raspberries. We are exploring how electrons diffuse through these systems. To do this, we perform cyclic chronopotentiometry where we cycle between periods of applying a voltage to achieve a certain current and periods where the current is stopped. We focus on the time-dependent decay of the voltage when the current is stopped and fit these decays with a bi-exponential model. We compare the results of devices with and without lithium perchlorate in the electrolyte solution since lithium lowers the energies of the acceptor states …

Dipole Cooperativity And Polarization Frustration Determine The Secondary Structure Distribution Of Short Alanine Peptides In Water, Ying Yuan, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

The physical driving forces for secondary structure preferences of hydrated alanine peptide are investigated with B3LYP-D3(BJ) and the adaptive force matching (AFM) method. The AFM fit to the DFT surface, ALA2022, provides excellent agreement with the nuclear magnetic resonance scalar coupling constants from experiments. In turn, the model is used to gain insight into the physical driving forces behind secondary structure preferences of hydrated peptides. DFT calculations with and without the Conductor-like Screening Model (COSMO) show that the α helix is stabilized by solvent polarization due to dipole cooperativity. The two adjacent amide groups in β strand form a near-planar …

Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

Two ways to create rigid versions of flexible models are explored. The rigid model can assume the Model’s Geometry (MG) as if the molecule is not interacting with any other molecules or the ensemble averaged geometry (EG) under a particular thermodynamic condition. Although the MG model is more straightforward to create, it leads to relatively poor performance. The EG model behaves similarly to the corresponding flexible model (the FL model) and, in some cases, agrees even better with experiments. While the difference between the EG and the FL models is mostly a result of flexibility, the MG and EG models …

The Kinetic Control Of Polymer Micelles; Chemical Functionality, Material Interactions, And Equilibration, Taylor Larison

Theses and Dissertations

Polymer micelles have found significant uses in areas such as, energy storage devices, catalysis, opto-electronics, drug-delivery, oil additives, and nanoreactors. In many of these applications the overall micelle size (aggregation number) and chemical functionalization determines performance. To progress towards more advanced materials synthesized from the facile bottom-up approach with polymeric micelles the implementation and study of thermodynamic handles were investigated. Here the kinetic control of micelles was studied across a range of applications; independent control over micelle functionality, the spatial orientation of multiple metal oxide nanoparticles in mesoporous materials via self-assembly, and the use of small-angle neutron scattering (SANS) to …

Coordination Environment And Thermodynamics Of Colloidal Quantum Dots In Polar Solvents, Nuwanthaka Prasad Jayaweera Millaniyage

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) have been extensively investigated due to their attractive properties such as size-tunable absorption and emission spectra, large molar extinction coefficients, and significant photostability. These properties make them promising candidates for optoelectronic, photocatalytic, and biomedical applications. Common synthetic procedures of QDs produce nanocrystals capped with long-chain fatty acid derivatives which are stabilized in high boiling point solvents. Especially for bioimaging applications, the exchange of these native hydrophobic ligands with hydrophilic ligands should be performed, while preserving the smaller hydrodynamic radius. The coordination environment and thermodynamic parameters of the ligand exchanges should be carefully investigated to engineer …

Reactive End Capped Polybenzimidazole Oligomers For High Temperature Thermosets And Improved Membranes For Electrochemical Devices, Caroline Marie Rohlfing

Theses and Dissertations

Polybenzimidazoles (PBI) are heterocyclic polymers that possess high thermal and oxidative stability. The inherent strength and chemical and thermal stability of PBI make it ideal for use in extreme environments; however, the current processing of PBI molded parts makes the process practically and economically unfavorable. These intrinsic properties make PBIs of particular interest for many industrial applications, varying from fabrics to membrane materials to molded parts. Processing these molded parts is extremely difficult, as the high glass transition temperature and extremely high melting point (>500°C) of PBI result in poor flow properties of PBI resins even at high temperatures. …

Sustainable Approaches To Photo-, Thermo-, And Electro-Chemical Reactions Of Amines, James David Sitter

Theses and Dissertations

In recent years, sustainable routes for chemical synthesis have garnered renewed interest. As the world continues to fight pollution and rising costs, it is imperative that new routes of synthesis that continuously fight the issues of pollution and waste are discovered, defined and explored. While traditional synthesis routes that require energy input typically require the burning of fossil fuels to produce heat, the amount of resources that go into the production of these fossil fuels and the sequestration of its waste to minimize its impact on the carbon footprint is enormous. Furthermore, sustainable chemistry research aims to decrease and minimize …

Structure Property Investigation And Applications Of Self-Assembled Triphenylamine Bis Urea Macrocycles, Md Faizul Islam

Theses and Dissertations

Porous organic crystals can be advantageous as nanoreactors and in sensing, separations, and storage. The Shimizu group utilizes bifurcated urea hydrogen bonding to direct the assembly small building block into pillars and columns affording functional porous crystals. Recently, our group has examined the incorporation of triphenylamines within the framework of bis-urea macrocycles. These macrocycles assemble into columns that contain the solvent of crystallization bound within the channels. Heating the crystals leads to removal of the solvent and activates the host for guest exchange by single-crystal-to-single[1]crystal transformations. Different electron accepting molecules can be encapsulated inside the pore of the host …