Digital Commons Network^™

Electrochemical Studies Of Organic And Organometallic Compounds In The Pursuit Of Electrocatalytic Carbon Dioxide Reduction, Joshua J. Ludtke

College of Science and Health Theses and Dissertations

Carbon dioxide is the main contributor to the greenhouse effect in the world today; developing renewable energy sources and addressing anthropogenic CO₂ release into the atmosphere are two key ways of addressing its increasing impact. Electrocatalytic reduction to products like methanol or carbon monoxide is one useful path to address the rapid increase of carbon dioxide, and the fac-M(bpy-R)(CO)₃X family of complexes (M = Mn or Re; bpy-R = substituted 2,2’-bipyridine; X = Cl, Br, etc.) is one class of effective CO₂ reduction catalysts. Although the capability of the rhenium complex Re(PyBimH)(CO)₃Cl (PyBimH …

Encirclement Of Moving Targets Using Noisy Range And Bearing Measurements, Cammy Peterson, Puneet Jain, Randal Beard

Faculty Publications

This paper presents theoretically justified controllers that use relative range and bearing measurements to steer a team of autonomous vehicles, operating without inertial position information, to circular trajectories around a constant-acceleration, constant-velocity, or stationary target. An extended Kalman filter is used to improve the noisy relative measurements and estimate the velocity of the moving target. These estimated values are used in the control laws to encircle constant-velocity moving targets. Lyapunov techniques are utilized to show that the vehicle will converge to the desired circular formations. Additionally, cooperating vehicles are shown to converge to a circular formation with equal temporal spacing …

Immobilized-Enzyme Reactors Integrated Into Analytical Platforms: Recent Advances And Challenges, Bert Wouters Dr, Sinead Currivan, Noor Abdulhussain, T. Hankemeier, Peter J. Schoenmakers

Articles

Immobilized-enzyme reactors (IMERs) are flow-through devices containing enzymes that are physically confined or localized with retention of their catalytic activities. IMERs can be used repeatedly and continuously and have been applied for (bio)polymer degradation, proteomics, biomarker discovery, inhibitor screening, and detection. Online integration of IMERs with analytical instrumentation, such as high-performance liquid chromatography (HPLC) systems, reduces the time needed for multi-step workflows, reduces the need for sample handling, and enables automation. However, online integration can also be challenging, as reaching its full potential requires complex instrumental setups and experienced users. This review aims to provide an assessment of recent advances …

Sd3 Ptov1 Ptms, Joshua Andersen

ScholarsArchive Data

MS data on PTOV1 PTMs

Sd1 14-3-3 Interactome For Ptov1 Manuscript, Joshua Andersen

ScholarsArchive Data

14-3-3 interactome

Sd2 Ptov1 Interactomics, Joshua Andersen

ScholarsArchive Data

PTOV1 interactome data

Sd1 14-3-3 Interactome For Ptov1 Manuscript, Joshua Andersen

ScholarsArchive Data

Excel data sheet of MS data from 14-3-3 interactomics

Heteroacene-Based Amphiphile As A Molecular Scaffold For Bioimaging Probes, Tharindu A. Ranathunge, Mahesh Loku Yaddehige, Jordan H. Varma, Cameron Smith, Jay Nguyen, Iyanuoluwani Owolabi, Wojciech Kolodziejczyk, Nathan I. Hammer, Glake Hill, Alex Flynt, Davita L. Watkins

Faculty Publications

The challenges faced with current fluorescence imaging agents have motivated us to study two nanostructures based on a hydrophobic dye, 6H-pyrrolo[3,2-b:4,5-b’]bis [1,4]benzothiazine (TRPZ). TRPZ is a heteroacene with a rigid, pi-conjugated structure, multiple reactive sites, and unique spectroscopic properties. Here we coupled TRPZ to a tert-butyl carbamate (BOC) protected 2,2-bis(hydroxymethyl)propanoic acid (bisMPA) dendron via azide-alkyne Huisgen cycloaddition. Deprotection of the protected amine groups on the dendron afforded a cationic terminated amphiphile, TRPZ-bisMPA. TRPZ-bisMPA was nanoprecipitated into water to obtain nanoparticles (NPs) with a hydrodynamic radius that was TRPZ-PG was encapsulated in pluronic-F127 (Mw …

Indicators Of Senescence And Their Relationship With The Antioxidant Response Element In Ovarian Cancer Cells—Toward A More Encompassing View Of Enzyme Activity Levels In Cells, Shaniqua Analycia Hayes

LSU Doctoral Dissertations

Enzymes and other related proteins are promising targets as biomarkers for cancer diagnostics, and it is therefore important to be able to quantify intracellular enzyme activity levels, not just presence of enzyme. Thus, there is a great need for the development of methods that offer spatiotemporal quantification of intracellular enzyme activity levels in respiring 2- and 3-dimensional cultures or their sample-processed variants. Previous studies have demonstrated that ß-gal is upregulated in senescence and in select ovarian cancers, and its expression/activity is upregulated when cells are under oxidative stress conditions. To that end, the primary goal of this work was to …

Social Constructivism In Chemistry Peer Leaders And Organic Chemistry Students, Aaron M. Clark

USF Tampa Graduate Theses and Dissertations

Social constructivist learning is a goal in many STEM programs. The goal of this dissertation is to shed light on what that pedagogy looks like in the context of organic chemistry courses and by peer leaders whose job is to implement this pedagogy with general chemistry and organic chemistry students. Learning is complex; the social constructivist ideas presented in this dissertation, however, are a straightforward means for promoting learning. Qualitative and quantitative methods used to explore social constructivist learning are outlined.

Three investigations were conducted: First, approaches to learning by students completing the first semester of a yearlong organic chemistry …

Mechanistic Investigation Of Neuropeptide S-Nitrosylation By Nitric Oxide Moieties: A Kinetic And Thermodynamic Approach, Vusumuzi Leroy Sibanda

Dissertations and Theses

This dissertation focuses on providing quantitative insights regarding kinetic, thermodynamic and mechanistic parameters of neuropeptide S-nitrosylation by nitrous acid (HNO₂), peroxynitrite (ONOO^-) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) to produce S-nitrosothiols (SNOs). Peptide thiol stability and the formation of SNOs from neuropeptides; arginine vasopressin (AVP), somatostatin-14 (SST-14) and urotensin II (U-II) was studied. Investigations into the effects of temperature, copper chelators and pH on peptide thiol autoxidation show that AVP, SST-14 and U-II thiols have half-lives of 30, 44 and 28.2 mins respectively at physiologically relevant temperature and pH in the absence of metal chelators. Target peptide thiols were …

Mechanisms Of Tetracycline Inactivation By Flavin-Dependent Tetracycline Destructases, Chanez Tiffany Valeena Symister

Arts & Sciences Graduate Student Theses and Dissertations

Antibiotic resistance is on track to become the next global pandemic. As the world grapples to return to normalcy after experiencing the devastating effects of Covid-19, it is evident that a proactive approach to public health crises can mitigate the mortality rate, economic cost, and the adverse effects to the mental wellbeing of the global population. With the rapidly increasing number of multidrug resistant pathogens invading the clinical environment, the problem exists that all existing antibiotic therapies will be obsolete. The ideal solutions to this problem would be to 1) develop new antibiotics that can overcome the current resistance mechanisms, …

Enantioselective Synthesis Of Β-Amino Acid Derivatives Using Amidine-Based And Bifunctional Organocatalysts, Matthew Robert Straub

Arts & Sciences Graduate Student Theses and Dissertations

Two new enantioselective methodologies have been developed that have important implications for the asymmetric synthesis of β-amino acids and their derivatives. First, chiral amidine-based catalyst (ABC) HBTM-2 catalyzed an asymmetric cyclocondensation between in situ activated fluoroacetic acid and N-sulfonyl aldimines to give α-fluoro-β-lactams in highly enantioenriched form, achieving modest to excellent diastereoselectivities. These reactive lactams can then be quenched with various alcohols and amines to deliver the α-fluoro-β-amino acid derivatives in moderate isolated yields. Secondly, bifunctional double hydrogen bond donor-amine organocatalysts enable the catalytic alcoholysis of various racemic N-carbalkoxy-3-substituted isoxazolidin-5-ones, resulting in their kinetic resolution. The enantioenriched unreacted isoxazolidinone and …

Thermal Properties Of 18f-Fdg Uptake And Imaging In Positron Emission Tomography Scans Of Cancerous Cells, Carleigh R. Eagle

PANDION: The Osprey Journal of Research and Ideas

Positron Emission Tomography (PET) scans can utilize a radioactive tracer, in this case 2-deoxy2-[fluorine-18] fluoro-D-glucose (¹⁸F-FDG), to visualize malignant tumors in cancer patients. The uptake was compared to glucose to understand the difference in thermal properties, which contribute to the ability to image the cancerous cells. The uptake of ¹⁸F-FDG by cancer cells and the imaging process of positron emission tomography were reviewed from a thermodynamic perspective. Gastrointestinal and neurological imaging techniques were reviewed to understand the role of PET imaging in different areas of the human body.

Formation Of Microcages From A Collagen Mimetic Peptide Via Metal-Ligand Interactions, Jeremy Gleaton, Ryan W. Curtis, Jean Chmielewski

Department of Chemistry Faculty Publications

Here, the hierarchical assembly of a collagen mimetic peptide (CMP) displaying four bipyridine moieties is described. The CMP was capable of forming triple helices followed by self-assembly into disks and domes. Treatment of these disks and domes with metal ions such as Fe(II), Cu(II), Zn(II), Co(II), and Ru(III) triggered the formation of microcages, and micron-sized cup-like structures. Mechanistic studies suggest that the formation of the microcages proceeds from the disks and domes in a metal-dependent fashion. Fluorescently-labeled dextrans were encapsulated within the cages and displayed a time-dependent release using thermal conditions.

Correlation Effects On Intramolecular C-H...Oh And O-H...O Hydrogen Bond Interactions In Azelaic Acid: An Ab Initio Study, Sabina Kalata, Alina Huang, Ruben Parra

DePaul Discoveries

Electron correlation effects on both conventional, O-H…O, and nonconventional, C-H…O, intramolecular hydrogen bonds present in a selected azelaic acid folded conformation were evaluated ab initio using HF and MP2 methodologies. The relative strength of the hydrogen bonds was examined through different indicators derived from geometry, vibrational frequencies, and electron density along the hydrogen bond path. The HF method results in weaker O-H…O and C-H…O hydrogen bonds when compared with the corresponding results using the MP2 method. Additionally, the stability of the folded azelaic conformation is found to depend on the level of theory used. Accordingly, the zero-point corrected energies of …

High Altitude Ballooning As A Platform For Measuring Ozone Uptake Over Agricultural Landscapes, Thomas Sykora, Mark Potosnak

DePaul Discoveries

Measuring plant health is a key aspect in maximizing crop outputs. One often overlooked risk to crop fields is damage caused by stomatal ozone uptake; measuring this uptake is an important tool in understanding crop losses. Traditional methods for measuring plant ozone uptake are prohibitively expensive and rely on equipment that cannot easily be moved. Here, we propose high-altitude weather ballooning as a cost-effective alternative for measuring ozone uptake on a regional (~10 km) spatial scale. Ozonesounde data was obtained with weather balloons launched from the National Oceanic and Atmospheric Administration research station in Boulder, Colorado. This data was then …

The Variability Of Seawater Carbonate Chemistry In Two Florida Urban Mangrove Ecosystems, Alexandrina R. Rangel

All HCAS Student Capstones, Theses, and Dissertations

Anthropogenic carbon dioxide (CO₂) emissions into the atmosphere are yielding serious impacts across the world’s ocean, including ocean acidification, sea level rise, and increasing seawater temperature. However, these changes are not occurring uniformly across all marine ecosystems. Coastal ecosystems, such as mangroves, already experience extreme and variable environmental conditions due to natural biogeochemical and physical processes. The goal of this study was to document small-scale variability in two urban mangrove ecosystems to gain insight into how ocean acidification will manifest within these systems. Using a stand-up paddleboard, a suite of sensors, and traditional bottle sampling techniques, we measured …

Quantifying Phosphatidylethanol From Blood Samples, James V. Defrancesco, Majid Afshar

Chemistry: Faculty Publications and Other Works

Disclosed herein is a method for quantifying phosphatidylethanol (“ PEth ”), direct ethanol biomarker, from a blood sample using gas chromatography mass spectrometry. The method disclosed herein is useful for diagnosing acute and chronic alcohol abuse.

Swir Emissive Rosindolizine Dyes With Nanoencapsulation In Water Soluble Dendrimers, Satadru Chatterjee, William E. Meador, Cameron Smith, Indika Chandrasiri, Mohammad Farid Zia, Jay Nguyen, Austin Dorris, Alex Flynt, Davita L. Watkins, Nathan I. Hammer, Jared H. Delcamp

Faculty Publications

Shortwave infrared (SWIR) emission has great potential for deep-tissue in vivo biological imaging with high resolution. In this article, the synthesis and characterization of two new xanthene-based RosIndolizine dyes coded ^PhRosIndz and ^tolRosIndz is presented. The dyes are characterized via femtosecond transient absorption spectroscopy as well as steady-state absorption and emission spectroscopies. The emission of these dyes is shown in the SWIR region with peak emission at 1097 nm. ^TolRosIndz was encapsulated with an amphiphilic linear dendritic block co-polymer (LDBC) coded 10-PhPCL-G3 with high uptake yield. Further, cellular toxicity was examined in vitro using HEK (human embryonic …

The Development And Optimization Of A Two-Dimensional Lc-Qqq-Ms-Method For The Combined Analysis Of Synthetic Cannabinoids And Designer Cathinones In Urine, Holly Penefsky

Electronic Theses and Dissertations

The compounds and chemical compositions of synthetic cannabinoids and designer cathinones are designed to mimic the intoxicating effects of D⁹-tetrahydrocannabinol and amphetamines, respectively. In order to skirt existing drug laws, non-controlled ingredients are used, and the original chemical structures of current drugs are being modified using analogs or derivatives. These continually changing chemical compositions pose a problem for policymakers, and forensic and analytical scientists, as users are able to attain a “legal high” and avoid detection in standard drug screens. Commonly, toxicology laboratories utilize a screening method, such as immunoassay, for the presumptive identification of designer drugs. When …

Impacts Of Oil And Gas Wastes On Landfill Leachate, Sewage Treatment Plants, And The Environment, Lauren Badertscher

Electronic Theses and Dissertations

Between January 2011 and March 2021 oil and gas wells in Pennsylvania produced

305,637,795 barrels of liquid waste and 6,992,957 tons of solid waste with the majority from

Marcellus Shale unconventional wells. This waste is not considered hazardous and over 89% of

the solid waste generated by unconventional and conventional oil and gas extraction has been

disposed of in landfills over the past decade. This study examined trends in the quantity of waste

produced and methods of disposal. Landfills accepting this waste were identified and their

general method of leachate treatment, using onsite facilities or offsite at wastewater treatment

plants, …

Molten-Salt-Assisted Annealing For Making Colloidal Znga2o4:Cr Nanocrystals With High Persistent Luminescence, Bhupendra B. Srivastava, Santosh K. Gupta, Swati Mohan, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Persistent luminescent nanocrystals (PLNCs) in the sub-10 nm domain are considered to be the most fascinating inventions in lighting technology owing to their excellent performance in anti-counterfeiting, luminous paints, bioimaging, security applications, etc. Further improvement of persistent luminescence (PersL) intensity and lifetime is needed to achieve the desired success of PLNCs while keeping the uniform sub-10 nm size. In this work, the concept of molten salt confinement to thermally anneal as-synthesized ZnGa2O4:Cr3+ (ZGOC) colloidal NCs (CNCs) in a molten salt medium at 650 °C is introduced. This method led to significantly monodispersed and few agglomerated NCs with a much improved …

The Role Of Hydrogen Bonding And Hydrogen Migration In Different Environments, Nassim Beiranvand

Chemistry Theses and Dissertations

Hydrogen bonding is one of the most important topics in chemistry and has been a subject of many studies for years, using both experimental techniques and computational methods. My dissertation focuses on mechanistic studies of various types of intermolecu-lar and intramolecular hydrogen bonding in di˙erent systems based on quantum chemical calculations. In my work, I investigated the interplay of ring puckering and hydrogen bonding in DNA building blocks; hydrogen bonding in natural and unnatural base pairs and the nature of dihydrogen bonding by applying the Ring Puckering Analysis and the Local Vibrational Mode Theory (LVM). An additional aim of my …

Tracking The Amide I And Αcoo− Terminal Ν(C=O) Raman Bands In A Family Of L-Glutamic Acid-Containing Peptide Fragments: A Raman And Dft Study, Ashley E. Williams, Nathan I. Hammer, Ryan C. Fortenberry, Dana N. Reinemann

Faculty and Student Publications

The E-hook of β-tubulin plays instrumental roles in cytoskeletal regulation and function. The last six C-terminal residues of the βII isotype, a peptide of amino acid sequence EGEDEA, extend from the microtubule surface and have eluded characterization with classic X-ray crystallographic techniques. The band position of the characteristic amide I vibration of small peptide fragments is heavily dependent on the length of the peptide chain, the extent of intramolecular hydrogen bonding, and the overall polarity of the fragment. The dependence of the E residue’s amide I ν(C=O) and the αCOO− terminal ν(C=O) bands on the neighboring side chain, the length …

Automated Parsing Of Flexible Molecular Systems Using Principal Component Analysis And K-Means Clustering Techniques, Matthew J. Nwerem

Computational and Data Sciences (MS) Theses

Computational investigation of molecular structures and reactions of biological and pharmaceutical interests remains a grand scientific challenge due to the size and conformational flexibility of these systems. The work requires parsing and analyzing thousands of conformations in each molecular state for meaningful chemical information and subjecting the ensemble to costly quantum chemical calculations. The current status quo typically involves a manual process where the investigator must look at each conformation, separating each into structural families. This process is time-intensive and tedious, making this process infeasible in some cases, and limiting the ability of theoreticians to study these systems. However, the …

Doping Of Conjugated Polymers: Preparation, Characterization And Device Fabrication, Kan Tang

Dissertations

Semiconducting conjugated polymers (CPs) as emerging materials for advanced electronic applications such as sensors, OPVs, and OEFTs has become an intriguing research topic in the past decades. It opens a new avenue of “flexible” electronics, which has shown great potential in next-generation electronic devices.

However, due to the nature of CP materials and related solution processing techniques, unlike almost perfectly crystalline silicon materials, CPs in the solid-state often exhibit much lower crystallinity if it is not complete amorphous, which severely hinder the electronic property and optical property of the materials. The crystallinity of CPs in a film is often uniquely …

College Of Natural Sciences Newsletter, August 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 8.

Page 1 Dean's Message
Page 2 Awards and Recognition
Page 3 Student Summer Research
Page 4 Media Coverage of CNS
Page 5 Wintrode Student Success Center
Page 6-7 Welcome to our new Faculty & Staff!
Page 8 One Day for State: Thursday, Sept. 2nd
Page 7 Open PRAIRIE Data; Fall Faculty Retreat 2021

Determination Of The Kinetic Roles Of The Membrane In The Catalysis Of Rasgefs By Using An Engineered Model Protein, Hanh My Hoang

Chemistry & Biochemistry Dissertations - Archive

Ras guanine nucleotide exchange factors (RasGEFs), which include Son of Sevenless (SOS), Ras Guanine Nucleotide Releasing Protein (RasGRP), and Ras Guanine Nucleotide Releasing Factor (RasGRF), catalyze nucleotide exchange of Ras upon activating signals. Crystal structure analyses suggest that catalytic cavities of RasGEFs are not deep enough to uphold their substrates. Given that RasGEFs are all membrane binding proteins, a novel “membrane supplement hypothesis” is proposed that RasGEFs in cytoplasm are catalytically unformed; and RasGEFs on membrane are catalytically competent. The reason RasGEFs are catalytically unformed without the support of membrane is because the catalytic sites of RasGEFs are not sufficiently …

Studies On Enantioselective Desymmetrizing Alkyne Hydrosilylation, Yao Chung Chang

Chemistry & Biochemistry Theses - Archive

This research focuses on the design and synthesis of enantioselective desymmetrizing α-hydrosilylation of propargyl alcohols to provide α-hydroxy (E)-vinylsilanes. Transition metal-catalyzed, regio-and stereoselective intramolecular hydrosilylation of propargylic alcohols with an easily removable acetal directing group has been studied. This project thus far screened 35 chiral ligands with rhodium (I) to achieve enantioselective alkyne hydrosilylation. This strategy consists of sequential hydrosilylation of bis-propargyl formate with iridium catalyst and intramolecular alkyne hydrosilylation with chiral rhodium catalyst. To this end, a variety of chiral phosphine ligands has been tested, yet an enantiomeric excess of the α-hydroxy (E)-vinylsilanes has not been fruitful thus far, …