Physical Sciences and Mathematics Commons^™

Synthesis Of Phenyl Carbamoylated Guanidine Functionalized Chitosan, Eduardo Hernandez Requejo

FIU Electronic Theses and Dissertations

The lack of solubility of the chitosan in organic solvents hinders its potential for chemical modifications. For this reason, it was hypothesized that the insertion of the phenyl carbamoylated guanidine moiety could lead to increased solubility in DMSO and new potential modifications and uses.

This research involved the synthesis of S-methyl phenyl carbamoylated guanidine (SMPCG) starting from the commercially available S-methyl isothiourea. This was followed by the reaction of the SMPCG with chitosan to yield phenyl carbamoylated guanidine functionalized chitosan (PCGCs) with a degree of substitution of 14%.

The chitosan derivative is fully soluble in DMSO and partially in DMF. …

Grotthuss Molecular Dynamics Simulations For Modeling Proton Hopping In Electrosprayed Water Droplets., Lars Konermann, Scott Kim

Chemistry Publications

Excess protons in water exhibit unique transport properties because they can rapidly hop along H-bonded water wires. Considerable progress has been made in unraveling this Grotthuss diffusion mechanism using quantum mechanical-based computational techniques. Unfortunately, high computational cost tends to restrict those techniques to small systems and short times. Molecular dynamics (MD) simulations can be applied to much larger systems and longer time windows. However, standard MD methods do not permit the dissociation/formation of covalent bonds, such that Grotthuss diffusion cannot be captured. Here, we bridge this gap by combining atomistic MD simulations (using Gromacs and TIP4P/2005 water) with proton hopping. …

Modified Guanidine-Containing Polymers For Intracellular Protein Delivery, Alfonso Barrios

FIU Electronic Theses and Dissertations

Protein-based therapeutics have gained significant attention for treating or curing various diseases, especially those untreatable by small molecule-drugs. Despite their widespread success and adoption, the cellular membrane remains a major obstacle for proteins to reach the inner compartments of the cell and have had limited applicability spanning only extracellular targets. Consequently, the efficient intracellular delivery of proteins offers tremendous potential to reach new, unexplored, and otherwise “undruggable” targets. Acknowledging the therapeutic need, research efforts aimed at facilitating the delivery of proteins using polymer-based nanoparticles have emerged.

Guanidine-containing polymers provide a promising platform to address the common hurdles associated with protein …

Detection And Quantification Of Arsenic Pollution With A Moss Bio-Indicator And Icp-Ms, Erin R. Bowey

University Honors Theses

Heavy metal pollution is a recognized concern with an established source of anthropogenic activity, which is ever-increasing. While work has been done to make the monitoring of some metals more accessible, resourceful, and efficient with the use of epiphytic moss as a bio-indicator, this method has not been optimized for the detection of arsenic. Previously used analytical instrumentation has not proven sensitive enough to reliably detect arsenic, creating a gap in the monitoring process. However, inductively coupled plasma mass spectrometry (ICP-MS) is proposed as the solution to fill this gap. Its potential for low limits of detection and quantification express …

Calcium Bistriflimide-Mediated Sulfur (Vi)–Fluoride Exchange (Sufex): Mechanistic Insights Toward Instigating Catalysis, Nicholas Ball, Brian Han, Samuel R. Khasnavis, Matthew Nwerem, Michael Bertagna, O Maduka Ogba

Pomona Faculty Publications and Research

We report a mechanistic investigation of calcium bistriflimide-mediated sulfur(VI)–fluoride exchange (SuFEx) between sulfonyl fluorides and amines. We determine the likely pre-activation resting state─a calcium bistriflimide complex with ligated amines─thus allowing for corroborated calculation of the SuFEx activation barrier at ∼21 kcal/mol, compared to 21.5 ± 0.14 kcal/mol derived via kinetics experiments. Transition state analysis revealed: (1) a two-point calcium-substrate contact that activates the sulfur(VI) center and stabilizes the leaving fluoride and (2) a 1,4-diazabicyclo[2.2.2]octane additive that provides Brønsted-base activation of the nucleophilic amine. Stable Ca–F complexes upon sulfonamide formation are likely contributors to inhibited catalytic turnover, and a proof-of-principle redesign …

The Regulation Of Atg9a-Mediated Aggrephagy By An Ulk1-Independent Atg13-Atg101 Complex, Joshua Youngs

Undergraduate Honors Theses

Aggrephagy, a type of autophagy, is an essential cellular process by which protein aggregates are collected and broken down in the lysosome. Protein aggregates are implicated in several diseases including Alzheimer’s disease, diabetes, and cancer. Here, we investigate the ATG13-ATG101 protein complex, a sub-complex of the canonical ULK1 complex whose regulatory role in aggrephagy is not completely understood. We also develop a protein fragment complementation (PFC) assay using the biotin ligase TurboID to study the functions of the ATG13-ATG101 complex with increased specificity. We demonstrate that ATG13 is required for optimal degradation of p62-ubiquitin condensates. We also show that a …

The Use Of Electrospun Nanofibers With Gold And Silver Nanostars For The Detection Of Fentanyl Using Surface Enhance Raman Spectroscopy, The Modification Of Current Gc-Ms Methods To Increase Separation And Detection Of Synthetic Cathinones In Mixtures, Daniel Rubin

FIU Electronic Theses and Dissertations

Many criminal cases involve the use or sale of illicit substances. The forensic analyst has many different techniques they can use to analyze samples to determine which illicit substance is present. This project aims at developing electrospun nanofibers with nanoparticles to analyze fentanyl by surface enhanced Raman spectroscopy, as well as modifying current GC-MS parameters to enhance separation and analysis of synthetic cathinones. Using the fibers with nanoparticles allowed for the detection of fentanyl standards at 1mg/ml while slowing the oven ramp rate and modifying the hold times led to an increase in separation and better fragmentation patterns for determination. …

Studies In The Use Of 1,1'-Di(1-Hydroxyethyl)Ferrocene As A Flame Retardant For Polyurethanes, Chanel Yeary

Electronic Theses & Dissertations

Significant research in non-toxic flame retardants (FR) has been performed in recent years since the dangerous consequences of halogenated FR were found. As early as the 1970’s, carcinogenic the side effects of halogenated compounds were being acknowledged. Since the early 2000’s halogenated FRs began being phased out of use due to these negative side effects. Since then, significant research has been exploring alternative effective flame retardants. Ferrocene (Fc) is a promising alternative to halogenated FRs due to its nontoxicity and FR properties. This research will report on the synthesis of 1,1’-di(1-hydoxyethyl) ferrocene (DHEFc) and its incorporation into a polyurethane. A …

Symmetry Progression And Possible Polar Metallicity In Nips3 Under Pressure, Nathan Harms, Takahiro Matsuoka, Subhasis Sanmanta, Amanda J. Clune, Kevin A. Smith, Amanda V. Haglund, Erxi Feng, Huibo Cao, Jesse S. Smith, David Mandrus, Heung-Sik Kim, Zhenxian Liu, Janice L. Musfeldt

Chemistry Publications and Other Works

van der Waals solids are ideal platforms for the discovery of new states of matter and emergent properties under external stimuli. Under pressure, complex chalcogenides like MPS₃ (M = Mn, Ni, Co, V) host sliding and structural transitions, insulator-to-metal transitions, the possibility of an orbitally-selective Mott state, piezochromism, and superconductivity. In this work, we bring together diamond anvil cell techniques, infrared and Raman scattering spectroscopies, and X-ray diffraction with a detailed symmetry analysis and first-principles calculations to uncover a series of high-pressure phases in NiPS₃. Remarkably, we find five different states of matter between ambient …

Metabolomic Analysis, Identification And Antimicrobial Assay Of Two Mangrove Endophytes, Stephen Thompson

USF Tampa Graduate Theses and Dissertations

Natural products have played major roles in drug discovery and provided sources for many new drugs. Secondary metabolites, also called natural products, are organic compounds that are produced from fungi, bacteria, and other living organisms. Secondary metabolites produced by endophytic fungi include alkaloids, phenols, peptides, enzymes, polyketides, and terpenes. Endophytic fungi are rich sources of secondary metabolites and demonstrate bioactivity against many human pathogens including the ESKAPE pathogens. This thesis explores the diverse roles of endophytic fungi and their production of unique secondary metabolites for potential drug discovery and development. Secondary metabolites from two endophytic fungi (EG10-21E-2-HDAC & TAP14-34A-2-HDAC), collected …

Bbt Side Mold Assy, Bill Hemphill

STEM Guitar Project’s BBT Acoustic Kit

This electronic document file set covers the design and fabrication information of the ETSU Guitar Building Project’s BBT (OM-sized) Side Mold Assy for use with the STEM Guitar Project’s standard acoustic guitar kit. The extended 'as built' data set contains an overview file and companion video, the 'parent' CADD drawing, CADD data for laser etching and cutting a drill &/or layout template, CADD drawings in AutoCAD .DWG and .DXF R12 formats of the centerline tool paths for creating the mold assembly pieces on an AXYZ CNC router, and support documentation for CAM applications including router bit specifications, feeds, speed, multi-pass …

Investigating Student Engagement In General Chemistry Active Learning Activities Using The Activity Engagement Survey (Aces), Nicole Naibert, Jack Barbera

Chemistry Faculty Publications and Presentations

Investigating student engagement in active learning activities could provide valuable insight into variations of student learning outcomes when active learning is included in a course. This study sought to explore students’ engagement in relation to active learning activities incorporated in a general chemistry lecture course using the Activity Engagement Survey (AcES). The AcES can be used to simultaneously assess students’ overall engagement, as well as dimensions above and beyond overall engagement including their combined behavioral/cognitive engagement, emotional engagement, and social engagement. As students’ engagement may be influenced by aspects related to the learning environment and context, differences in engagement were …

Synthesis And Antibacterial Testing Of Novel Thiosulfonate Compounds, Lindsay I. Blume

USF Tampa Graduate Theses and Dissertations

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) are increasing concerns in the medical community. In addition to the threat of Staphylococcus aureus, the increase in number and severity of infections caused by other antibiotic-resistant bacteria is problematic to human health, particularly among the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter). The antibiotics like the penicillins and cephalosporins used commonly to treat MRSA, VRSA, and ESKAPE pathogens have continued to decline in the effectiveness. Our laboratory has developed a number of new families of anti-MRSA and anti-VRSA antibacterial compounds. In this thesis, …

Probing The Link Between Pancratistatin And Mitochondrial Apoptosis Through Changes In The Membrane Dynamics On The Nanoscale, Stuart R. Castillo, Brett W. Rickeard, Mitchell Dipasquale, Michael H.L. Nguyen, Aislyn Lewis-Laurent, Milka Doktorova, Batuhan Kav, Markus S. Miettinen, Michihiro Nagao, Elizabeth G. Kelley, Drew Marquardt

Chemistry and Biochemistry Publications

Pancratistatin (PST) is a natural antiviral alkaloid that has demonstrated specificity toward cancerous cells and explicitly targets the mitochondria. PST initiates apoptosis while leaving healthy, noncancerous cells unscathed. However, the manner by which PST induces apoptosis remains elusive and impedes the advancement of PST as a natural anticancer therapeutic agent. Herein, we use neutron spin-echo (NSE) spectroscopy, molecular dynamics (MD) simulations, and supporting small angle scattering techniques to study PST's effect on membrane dynamics using biologically representative model membranes. Our data suggests that PST stiffens the inner mitochondrial membrane (IMM) by being preferentially associated with cardiolipin, which would lead to …

The Synthesis Of Deuterated Isohumulones For Use As Internal Standards In Lc-Ms Stable Isotope Dilution Assays, Patrick Gleason, Bruce Hamper Dr.

Undergraduate Research Symposium

Humulones are compounds that are prevalent in the hops flowers (Humulus Lupulus) used in beer brewing. These compounds undergo isomerization during the brewing process, and the resulting isohumulones are considered to be the primary contributors to the bitter flavors present in beer. As such, quantifying their presence, and the relative presence of their homologs(n-, co-, ad-), is of great importance in the characterization of beer. In this effort, one of the homologs of humulone (co) was isolated before being subsequently isomerized and deuterated for the purpose of analyzing beer by stable isotope dilution assay mass spectrometry(SIDA-MS). The addition of this …

Synthesis, Physicochemical Characterization, And Catalytic Evaluation Of Fe3+-Containing Ssz-70 Zeolite, Christopher M. Lew, Cong Yan Chen, Gary J. Long, Fernande Grandjean, Andrew S. Ichimura, Dan Xie, Nicolás A. Grosso-Giordano, Khetpakorn Chakarawet, Howard S. Lacheen, Kurt O. Jensen, Abraham Martinez, Alexander Katz, Bi Zeng Zhan, Stacey I. Zones

Chemistry Faculty Research & Creative Works

Whereas one-dimensional, 10-membered ring zeolites are typically used for hydroisomerization, Fe3⁺-containing SSZ-70 (Fe-SSZ-70) shows remarkable isomerization selectivity for a zeolite containing 12- and partially blocked 14-membered rings, in addition to 10-membered rings. Fe-SSZ-70 was compared to Al3⁺-containing SSZ-70 (Al-SSZ-70) in constraint index and n-decane hydrocracking tests. Fe-SSZ-70 exhibited a 74% total isomer yield (64% yield of monobranched isomers and 10% cracking yield) at 85% conversion compared to 49% total isomer yield (41% yield of monobranched isomers and 36% cracking yield) for Al-SSZ-70 at the same conversion. The selectivity to isomerization is attributed to the weaker acid …

Collaborative Research: Surface-Specific Aerosol Chemistry: Direct Observations, Kinetics, And Environmental Impact, Yi Rao

Funded Research Records

No abstract provided.

Noncanonical Amino Acid Mutagenesis In Response To Recoding Signal-Enhanced Quadruplet Codons, Yan Chen, Xinyuan He, University Of Nebraska-Lincoln, Kun Liu, Tian Gao, Wei Niu, Jiantao Guo

Chemistry Department: Faculty Publications

While amber suppression is the most common approach to introduce noncanonical amino acids into proteins in live cells, quadruplet codon decoding has potential to enable a greatly expanded genetic code with up to 256 new codons for protein biosynthesis. Since triplet codons are the predominant form of genetic code in nature, quadruplet codon decoding often displays limited efficiency. In this work, we exploited a new approach to significantly improve quadruplet UAGN and AGGN (N = A, U, G, C) codon decoding efficiency by using recoding signals imbedded in mRNA. With representative recoding signals, the expression level of mutant proteins containing …

Biomass Estimation Of Marine Biofilms On Plastic Surfaces, Kian Banihashemi, Fernando Javier Gil

Biological Sciences

Plastics have become a major source of marine pollution, which threatens food safety and quality, human health, and marine ecosystems. Due to the drastic negative effects of plastics in a marine environment, alternative biodegradable plastics are being generated that are more eco-friendly and have less environmental impact. Though some of these plastics are known to biodegrade, the process of degradation for bioplastics has not been heavily studied in a marine environment. This pilot project sought to both quantify the process of biodegradation and compare across different methods for effectiveness of biomass estimation, which serves as an indicator of biodegradation. Plastics …

College Of Natural Sciences Newsletter, May & June 2022, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 3, Issue 4

Page 1 Dean's Message
Page 2 Awards and Recognition
Page 3-4 The path to a Doctorate Degree
Page 4 American Indian Student Center Native Graduate Honoring Ceremony
Page 5 Celebrating the lives of those who touched the College
Page 6 Media coverage of CNS
Page 7 Open PRAIRIE
Page 8-10 CNS Graduation Festivities
Page 11-14 Spring 2022 Dean's List
Page 16 Richard and Janice Vetter Endowed Professorship in Biotechnology.position

Highly Swellable Hydrogels Prepared From Extensively Oxidized Lignin, Jihyeon Hwang, Daniella V. Martinez, Estevan J. Martinez, Gift Metavarayuth, Dustin Goodlett, Qi Wang, Mitra Ganewatta, Michael S. Kent, Chuanbing Tang

Faculty Publications

Biopolymers such as lignin are gaining renewed appeal due to the need for sustainable materials. Herein, we used chelator-mediated Fenton (CMF) chemistry to oxidize Kraft lignin to develop sustainable super absorbent materials. The CMF chemistry adds oxygen, opens aromatic rings and increases COOH content, producing hydrophilic lignin without depolymerization. UV absorption, molecular weight, elemental analysis, and titration were used to study the chemical compositions of CMF-processed lignin. Then the chemically modified hydrophilic lignin was used to produce lignin-based hydrogels utilizing an aqueous polymerization and cross-linking reaction that enabled tunable properties. The resulting lignin hydrogels absorbed water up to 96% and …

Comprehensive Review Of Polymer And Polymer Gel Treatments For Natural Gas-Related Conformance Control, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. …

Development Of Quantitative Methods To Study Pfas Using Proton Induced Gamma-Ray Emission, Colin Langton

Honors Theses

Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals that have become a major environmental concern. They can be found in a broad range of everyday products and pose a significant risk to the public due to their adverse health effects. They are persistent, bioaccumulate and do not break down in the environment. This project specifically aims to determine the concentration of Fluorine, a key identifier of PFAS, in environmental samples. To do this, we employ proton induced gamma-ray emission (PIGE) to screen for Fluorine within our samples. PIGE is performed at the Union College Ion Beam Analysis Laboratory using a …

Equilibrium And Dynamic Surface Tension Behavior In Colloidal Unimolecular Polymers (Cup), Ashish Zore, Peng Geng, Michael R. Van De Mark

Chemistry Faculty Research & Creative Works

Studies of the interfacial behavior of pure aqueous nanoparticles have been limited due tothe difficulty of making contaminant-free nanoparticles while also providing narrow size distribu-tion. Colloidal unimolecular polymers (CUPs) are a new type of single-chain nanoparticle with a particle size ranging from 3 to 9 nm, which can be produced free of surfactants and volatile organic contents (VOCs). CUP particles of different sizes and surface charges were made. The surface tension behavior of these CUP particles in water was studied using a maximum bubble pressure tensiometer. The equilibrium surface tension decreased with increasing concentration and the number of charges present …

State-To-State Rate Coefficients For Hcs+In Rotationally Inelastic Collisions With H2at Low Temperatures, Otoniel Denis-Alpizar, Ernesto Quintas-Sánchez, Richard Dawes

Chemistry Faculty Research & Creative Works

HCS⁺ ions have been detected in several regions of the interstellar medium (ISM), but an accurate determination of the chemical-physical conditions in the molecular clouds where this molecule is observed requires detailed knowledge of the collisional rate coefficients with the most common colliders in those environments. In this work, we study the dynamics of rotationally inelastic collisions of HCS⁺ + H₂ at low temperature, and report, for the first time, a set of rate coefficients for this system. We used a recently developed potential energy surface for the HCS⁺-H₂ van der Waals complex and …

Analysis Of The Zebrafish Olfactory System Using Immunohistochemistry And Enhanced Techniques Of Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Tara Lynn Maser

Dissertations

Desorption electrospray ionization (DESI-MS) is an ambient ionization technique where the sample is analyzed directly from a surface with very minimal sample preparation under ambient conditions and follows ESI-like ionization mechanisms. DESI-MS has proven powerful in analyzing or imaging lipids and other small molecules directly from biological samples and even allows for subsequent histological staining and analyses. However, DESI-MS is less widely used for protein analysis due to a lack of sensitivity and the complex diversity of proteins in biological samples.

A major goal of this research has been to obtain new neurobiological knowledge by combining histology and mass spectrometry …

Crude Oil Characterization Using Gas Chromatography, Ion Mobility Spectrometry And Mass Spectrometry, Clement A. Olanrewaju

FIU Electronic Theses and Dissertations

The characterization of crude oils at the compositional level remains challenging due to their high chemical complexity and isomeric diversity. The present work expands the analytical separation space of chemical components in crude oils by coupling gas chromatography (GC), trapped ion mobility spectrometry (TIMS), and mass spectrometry (GC-TIMS-MS and TIMS-FT-ICR MS) for the effective separation and identification of isomeric compounds. The coupling of GC and TIMS-MS platform enhanced the peak capacity and showed complementary isomeric separation. The combination of GC-TIMS-MS and GC-EI-MS technique provided a comprehensive characterization of PAHs and similar compounds from crude oils on the basis of retention …

Investigating The Mechanisms Driving Mercury Reduction And Emissions In Soil, Hamil Patel

Student Theses

The water-induced emission of mercury from soil has been studied, but a complete understanding of the mechanisms driving mercury reduction and emission in soil has not been reached. The current understanding is an immediate expulsion of soil gaseous mercury upon water treatment and an upward transport of dissolved soil ionic mercury as the water evaporates. We analyzed emissions from several types of samples using various methods to further our understanding on the mechanisms involved. Light-induced emissions from aqueous samples of humic acid (HA) spiked with mercury (II) chloride (HgCl₂) showed that at higher concentrations of HA, less mercury …

The Design, Synthesis, And Characterization Of Copper-Based Metal-Organic Frameworks For Their Investigation Against Cancer And Their Effect As Anti-Microbial Agents, Sandy Elmehrath

Dissertations

A wide range of nanomaterials have been developed for biomedical applications, such as drug delivery, biomedical imaging, and sensors. Nanomaterials can include nanoparticles (NPs) and nanofibers with various dimensions that are both natural and synthetic. A successful nanomaterial, for use in biological applications, is characterized by its biocompatibility, biodegradability, intrinsic high surfaces area, high interconnected porosity, and functionality. These features were achieved with the development of metal-organic framework (MOF) nanostructures. MOFs are assemblies of metal ions and organic linkers that are built into different geometries and can exist in all dimensions (up to 3-D). The choice of linkers with well-defined …

Equilibrium And Dynamic Surface Tension Behavior In Colloidal Unimolecular Polymers (Cup), Ashish Zore, Peng Geng, Michael R. Van De Mark

Chemistry Faculty Research & Creative Works

Studies of the interfacial behavior of pure aqueous nanoparticles have been limited due tothe difficulty of making contaminant-free nanoparticles while also providing narrow size distribu-tion. Colloidal unimolecular polymers (CUPs) are a new type of single-chain nanoparticle with a particle size ranging from 3 to 9 nm, which can be produced free of surfactants and volatile organic contents (VOCs). CUP particles of different sizes and surface charges were made. The surface tension behavior of these CUP particles in water was studied using a maximum bubble pressure tensiometer. The equilibrium surface tension decreased with increasing concentration and the number of charges present …