Physical Sciences and Mathematics Commons^™

Molecular Devices For Measuring Weak Solvophobic Interactions And The Development Of Pedagogical Tools For Organic Chemistry Students, Alexander N. Manzewitsch

Theses and Dissertations

The main topics of this dissertation are: 1) the development and discussion of a new molecular balance for measuring alkyl-alkyl interactions in a wide array of organic solvents, 2) the development of linear solvation energy relationships between solvent interaction parameters and solvent accessible surface area (SASA) in CH-arene interactions, and 3) the development of online resources for helping undergraduate students perform organic chemistry mechanisms problems well.

The solvophobic effect, that is the forced association between two solutes due to intermolecular attraction of the solvent molecules, is ubiquitous in organic chemistry and responsible for many significant phenomena thereof. However, there is …

Pc-01 Synthesis Of Zinc Glycoconjugated Phthalocyanines As A Potential Phototherapeutic, Jessica A. Silva-Conejo, Katrina Mccarter, Tessa Greene, Joshua V. Ruppel

SC Upstate Research Symposium

Photodynamic Therapy (PDT) uses photosensitizers that are activated by light to produce singlet oxygen that can cause cell damage and potential cell death. Phthalocyanines are promising photosensitizers due to their absorption at clinically relevant wavelengths, meaning that they absorb at a wavelength that can penetrate deeper into tissues.

One challenge with using Phthalocyanines is that they have very low solubility in biological media. One potential approach to increase solubility is through glycoconjugation. Glycoconjugation can also be used as a strategy to increase selectivity toward targeted tissues. Glycoconjugated phthalocyanines can be synthesized using a copper catalyzed azide-alkyne cycloaddition reaction, otherwise known …

Considerations For Curricular Reform In Undergraduate Chemistry: Cooperative Adoption Factors, Modeling Social Influence, And Focusing On Specific Populations, Jacob D. Mcalpin

USF Tampa Graduate Theses and Dissertations

This dissertation will go through the details of three projects highlighting considerations for curricular reforms in undergraduate chemistry. Improving the teaching of chemistry is facilitated by considering the problem from multiple directions, namely, faculty and students. In addition to the multiple perspectives, this dissertation also seeks to bring new methodologies into the spotlight to improve the toolbox for other chemistry or discipline-based education researchers. Additionally, this dissertation has shown in several locations how focusing in on subgroups within populations can reveal findings that would not have been apparent from a global average of the population. The three project describes in …

Interdisciplinary Diffusion Lab, Sable Rosana Canales, Chloe Gaban

Andrews University Teaching and Learning Conference

Diffusion is a principle in Physics, Chemistry, and Biology. Students can model the rate of diffusion based on particle size by contrasting blue and yellow dyes. Two petri dishes containing agar-agar receive a drop of dye at the center. The radius of expansion is recorded over time and variance increases linearly with time. Diffusion constants vary by particle size, allowing for a size ratio comparison between blue and yellow dyes. Relating the data to cells, students predict that smaller molecules diffuse into living cells, whereas larger molecules need some assistance from protein channels as in facilitated diffusion.

Traffic Lights For Catalysis: Stimuli-Responsive Molecular And Extended Catalytic Systems, Grace C. Thaggard, Johanna Haimeri, Roland A. Fischer Prof. Dr., Kyoung Chul Park, Natalia B. Shustova Prof. Dr.

Faculty Publications

The advances made in the field of stimuli-responsive catalysis during the last five years with a focus on the novel recently-emerged directions and applications have been surveyed. Metal-free catalysts and organometallic complexes, as well as biomimetic systems and extended structures, which display switchable catalytic activity for a variety of organic transformations, are discussed. Light-activated systems comprised of photochromic molecules capable of modulating reaction rate, yield, or enantioselectivity based on geometric and electronic changes associated with photoisomerization are the focus of the detailed discussion. Alternative stimuli, including pH and temperature, which could be applied either alone or in combination with light, …

Virtual And In Vitro Screening Of Natural Products Identifies Indole And Benzene Derivatives As Inhibitors Of Sars-Cov-2 Main Protease (MPro), Dony Ang, Riley Kendall, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The rapid spread of the coronavirus disease 2019 (COVID-19) resulted in serious health, social, and economic consequences. While the development of effective vaccines substantially reduced the severity of symptoms and the associated deaths, we still urgently need effective drugs to further reduce the number of casualties associated with SARS-CoV-2 infections. Machine learning methods both improved and sped up all the different stages of the drug discovery processes by performing complex analyses with enormous datasets. Natural products (NPs) have been used for treating diseases and infections for thousands of years and represent a valuable resource for drug discovery when combined with …

Stabilizing G-Quadruplex Dna And Rna Structures With Ionic Liquids, Timothy Vaden

College of Science & Mathematics Departmental Research

Stabilizing DNA and RNA for long-term room-temperature storage is important for many biotechnological applications including oncology pharmaceuticals and mRNA-based vaccines (e.g. Covid vaccines). This poster shows that ionic liquids can improve the thermal stability of G-quadruplex DNA and RNA structures, and motivates further studies of ionic liquid-based materials for DNA / RNA stabilization.

Advancing Nanofiber Research: Assessing Non Solvent Contributions To Structure Using Coaxial Electrospinning, Ping Lu

College of Science & Mathematics Departmental Research

Nanofibers play a vital role as precursors for fabricating a wide array of products spanning environmental and energy sustainability, biomedical, and healthcare applications The nanofiber characteristics, such as porosity, domains, and interfaces, are strongly influenced by the phase separation behavior among polymers, solvents, and nonsolvents in the liquid jet during the nanofabrication process However, the precise control and understanding of these phenomena at the level of individual nanofibers still need to be improved due to the need for more current technologies to provide sufficient spatial and temporal resolution To address this challenge, we employed coaxial electrospinning with a nonsolvent core …

Damped Oscillating Phosphoryl Transfer Reaction In The Cyanobacterial Circadian Clock, Hye In Jang, Pyonghwa Kim, Yongick Kim

Chemistry Faculty Research

Most organisms have circadian clocks to ensure the metabolic cycle to resonate with the rhythmic environmental changes without “damping,” or losing robustness. Cyanobacteria is the oldest and simplest form of life that is known to harbor this biological intricacy. Its KaiABC-based central oscillator proteins can be reconstituted inside a test tube, and the post-translational modification cycle occurs with 24 h periodicity. KaiC’s two major phosphorylation sites, Ser-431 and Thr-432, become phosphorylated and dephosphorylated by interacting with KaiA and KaiB, respectively. Here, we mutate Thr-432 into Ser to find the oscillatory phosphoryl transfer reaction damps. Previously, this mutant KaiC was reported …

Bimetallic Compound Catalysts With Multiple Active Centers For Accelerated Polysulfide Conversion In Li-S Batteries, Wu-Xing Hua, Jing-Yi Xia, Zhong-Hao Hu, Huan Li, Wei Lv, Quan-Hong Yang

Journal of Electrochemistry

Practical applications of lithium-sulfur (Li-S) batteries are hindered mainly by the low sulfur utilization and severe capacity fading derived from the polysulfide shuttling. Catalysis is an effective remedy to those problems by promoting the conversion of polysulfides to reduce their accumulation in the electrolyte, which needs the catalyst to have efficient adsorption ability to soluble polysulfides and high activity for their conversion. In this work, we have proposed a bimetallic compound of NiCo₂S₄ anchored onto sulfur-doped graphene (NCS@SG) to fabricate a catalytic interlayer for Li-S batteries. Compared to CoS, the NiCo₂S₄ demonstrated much higher …

Coni-Based Bimetal-Organic Framework Derived Carbon Composites Multifunctionally Modified Separators For Lithium-Sulfur Batteries, Yan-Jie Wang, Hong-Yu Cheng, Ji-Yue Hou, Wen-Hao Yang, Rong-Wei Huang, Zhi-Cong Ni, Zi-Yi Zhu, Ying Wang, Ke-Yi Wei, Yi-Yong Zhang, Xue Li

Journal of Electrochemistry

The commercial application of lithium-sulfur batteries (LSB) is still limited by the irreversible capacity fading caused by the shuttle of lithium polysulfides (LIPS). To address this issue, a bimetal (nickel, cobalt)-organic framework (MOF) derived carbon, (Ni, Co)/C, was prepared to modify the separator. The multifunctionally modified separator effectively captures LIPS, ensuring the stability and reversibility of sulfur fixation, while providing catalytic activity and improving ionic conductivity. The cobalt metal has a larger coordination number, more pore structure distribution, larger specific surface area, more surface C=O, and smaller particle size to achieve a large and rapid chemical sulfur fixation. The high …

Preface To The Special Issue On Lithium-Sulfur Batteries, Jia-Jia Chen, Ren-Jie Chen, Zhong Jin

Journal of Electrochemistry

No abstract provided.

Recent Research Progresses Of Solid-State Lithium-Sulfur Batteries, Yu Luo, Ru-Qin Ma, Zheng-Liang Gong, Yong Yang

Journal of Electrochemistry

All solid-state lithium-sulfur batteries (ASSLSBs) are considered to be one of the most promising next-generation energy storage systems, due to the promises of high energy density and safety. Although the use of solid-state electrolytes could effectively suppress the "shuttle effect" and self-discharge of the conventional liquid lithium-sulfur (Li-S) battery, the commercialization of ASSLSBs has been seriously hampered by the electrolyte degradation, electrode/electrolyte interfacial deterioration, electrochemo-mechanical failure, lithium dendrite growth and electrode pulverization, etc. This paper provides a comprehensive review of recent research progresses on the solid-state electrolytes, sulfur-containing composite cathodes, lithium metal and lithium alloy anodes, and electrode/electrolyte interfaces in …

A Review On Solid-State Li-S Battery: From The Conversion Mechanism Of Sulfur To Engineering Design, Huan-Huan Jia, Chen-Ji Hu, Yi-Xiao Zhang, Li-Wei Chen

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries attract sustained attention because of their ultrahigh theoretical energy density of 2567 Wh·kg^–1 and the actual value over 600 Wh·kg^–1. Solid-state Li-S batteries (SSLSBs) emerge in the recent two decades because of the enhanced safety when compared to the liquid system. As for the SSLSBs, except for the difference in the conversion mechanism induced by the cathode materials themselves, the physical-chemical property of solid electrolytes (SEs) also significantly affects their electrochemical behaviors. On account of various reported Li-S batteries, the advantages and disadvantages in performance and the failure mechanism are discussed in this review. …

Conformational Dynamics And Free Energy Studies Of Dna And Other Biomolecules, Paul B. Orndorff

USF Tampa Graduate Theses and Dissertations

This work uses molecular dynamics simulations and enhanced sampling methods to investigate both the qualitative and quantitative properties of biomolecular systems. Conformational dynamics are critical in the study of biomolecular systems. Application of computer simulations to study dynamics of biomolecular systems allows for motions to be readily investigated at a resolution not possible in experimental techniques. In this work, the dynamics of uracil damaged and undamaged DNA is studied via molecular dynamics simulations. Uracil results in DNA from either misincorporation in the replication process or through spontaneous deamination of cytosine, and its presence in DNA can lead to mutations in …

Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji

Hadhramout University Journal of Natural & Applied Sciences

In this research, two new azo dyes, 9-(2-Hydroxy-ethoxymethyl)-2-(2-hydroxy5nitrophenylazo)-1,9-dihydro-purin-6-one and 4-(2-Hydroxy-napHthalen-1-ylazo)-N-(5-methyl-isoxazol-3-yl)-benzenesulfonamide, derived from Acyclovir and Sulfamethoxazole was synthesized. The first dye synthesis was started by diazation of acyclovir, then combined with 4-nitrophenol activated with potassium hydroxide 10%, yielding 80%, and its purity was verified by thin layer chromatography (TLC). The second dye synthesis was started by diazation of Sulfamethoxazole then combined with β-naphthol activated with potassium hydroxide 10%, yielding 87%, and its purity was verified by thin layer chromatography (TLC). The identity of the resulting pigments was determined based on spectroscopic methods such as infrared spectroscopy, proton nuclear magnetic resonance spectrum …

Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder

Undergraduate Research Symposium

Triple-negative breast cancer (TNBC) is one of the most aggressive and challenging breast cancer subtypes to treat, as these cancer cells lack three common receptors: estrogen, progesterone, and human epidermal growth factor receptor 2. The multiple oxidation states transition metals can occupy have made this narrowly explored group popular for anti-cancer research in recent decades. Furthermore, the success of cisplatin, which has platinum as a metal center, while being a cancer-fighting agent with serious side effects, has caused other metal centers to be investigated as possible alternatives as chemotherapeutic drugs. Copper, as a biologically essential metal, makes an attractive candidate …

Carbon Dioxide-Induced Corrosion Of Aisi 4140 Steel In Acidified Artificial Geothermal Brine, Anawati Anawati, Rayhan Izzat, Riene Kaelamanda Pragitta, Rafli Ihsan Hernandi

Makara Journal of Science

Carbon dioxide (CO₂)-induced corrosion often occurs in the structural materials of geothermal industry. The presence of CO₂ influences the formation of various corrosion products. This research investigates the effect of dissolved CO₂ in acidic brines on the corrosion behavior of AISI 4140 steel at atmospheric pressure. The brines were the standard brine, Ca-free brine, and high-salinity brine. The corrosion behavior was studied using electrochemical and immersion tests. A cyclic polarization test showed that the corrosion rate was higher in dissolved CO₂ brine than in non-CO₂ brine, and an immersion test demonstrated a similar result. …

Quantitation Of Female Newt Tetrodotoxin Concentrations And Their Impact In The Newt-Garter Snake Evolutionary Arms Race, Anna Frey, David Green Dr., Lee Kats Dr., Gary Bucciarelli Dr.

Seaver College Research And Scholarly Achievement Symposium

As this work is not yet published, the authors have requested the removal of the abstract.

Studies On Bonding, Syntheses, And Applications Of Diarylhalonium Compounds, Shubhendu Karandikar

Dissertations and Theses

Organic compounds containing functionalized benzenoid rings have found tremendous applications in pharmaceuticals, agrochemicals, commodity chemicals, and beyond. As a result, development of methods for the synthesis of functionalized benzenoid rings has gained much attention from the synthetic community. Although many transition-metal mediated methods to functionalize benzenoid rings are known, there has been an upsurge of activity in developing protocols for decoration of benzenoid cores promoted by p-block elements. This excitement stems from the sustainability of earth-abundant elements and unique reactivity patterns observed within the p-block. Among these, transformations promoted by hypervalent halogen compounds, and especially, the diarylhalonium salts are very …

7-Deazaguanines In Dna: Functional And Structural Elucidation Of A Dna Modification System, Samanthi Herath Gedara, Andrew Gustafson, Dirk Iwata-Reuyl, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

The modified nucleosides 2′-deoxy-7-cyano- and 2′-deoxy-7-amido-7-deazaguanosine (dPreQ₀ and dADG, respectively) recently discovered in DNA are the products of the bacterial queuosine tRNA modification pathway and the dpd gene cluster, the latter of which encodes proteins that comprise the elaborate Dpd restriction–modification system present in diverse bacteria. Recent genetic studies implicated the dpdA, dpdB and dpdC genes as encoding proteins necessary for DNA modification, with dpdD–dpdK contributing to the restriction phenotype. Here we report the in vitro reconstitution of the Dpd modification machinery from Salmonella enterica serovar Montevideo, the elucidation of the roles of each protein and the X-ray …

Apkcs Role In Neuroblastoma Cell Signaling Cascades And Implications Of Apkcs Inhibitors As Potential Therapeutics, Sloan Breedy

USF Tampa Graduate Theses and Dissertations

Neuroblastoma (NB) is a cancer that develops in the neuroblasts. It is the most common cancer in children under the age of 1 year, accounting for approximately 6% of all cancers. The prognosis of NB is linked to both age and degree of cell differentiation. This results in a range of survival rates for patients, with outcomes ranging from recurrence and mortality to high survival rates and tumor regression. Our previous work indicated that PKC-ι promotes cell proliferation in NB cells through the PKC-ι/Cdk7/Cdk2 cascade. We report on two atypical protein kinase inhibitors as potential therapeutic candidates against BE(2)-C and …

The Concentration Of Heavy Metals In Lincoln Nebraska's Tap Water, Evan Neuhaus

Honors Theses

Heavy metals are commonplace in nature, and are typically found in scarce quantities in all drinking sources. However, in high enough concentrations, they can have a myriad of negative health effects. This study seeks to find the concentrations of such metals in the Lincoln water supply utilizing the resources of the Water Center at the University of Nebraska at Lincoln. To test for discrete concentrations of trace elements, a method of using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was implemented. ICP-MS uses plasma to ionize and atomize a sample which is then filtered into a series of cones into a …

Diazirines And Oxaziridines As Nitrogen Transfer Reagents In Drug Discovery, Khalilia C. Tillett

USF Tampa Graduate Theses and Dissertations

Synthetic organic chemistry has long served as a driver of innovation in the drug discovery and development process. Given the prevalence of the nitrogen atom in small molecule drugs, improved methods for C–N bond installation are in high demand. Heteroatom transfer reagents such as oxaziridines and diazirines can be used to selectively deliver nitrogen atom(s) to organic compounds. Herein, I’ll describe my work utilizing Armstrong’s oxaziridine (TBDOT) in peptide backbone modification, and diazirines (TPD) in the development of a hydroamination reaction.

Peptide backbone N-amination has emerged as an attractive peptidomimetic strategy in the design of amyloid aggregation inhibitors. In addition …

Chatgpt As Metamorphosis Designer For The Future Of Artificial Intelligence (Ai): A Conceptual Investigation, Amarjit Kumar Singh (Library Assistant), Dr. Pankaj Mathur (Deputy Librarian)

Library Philosophy and Practice (e-journal)

Abstract

Purpose: The purpose of this research paper is to explore ChatGPT’s potential as an innovative designer tool for the future development of artificial intelligence. Specifically, this conceptual investigation aims to analyze ChatGPT’s capabilities as a tool for designing and developing near about human intelligent systems for futuristic used and developed in the field of Artificial Intelligence (AI). Also with the helps of this paper, researchers are analyzed the strengths and weaknesses of ChatGPT as a tool, and identify possible areas for improvement in its development and implementation. This investigation focused on the various features and functions of ChatGPT that …

Amplifying Reactivity Of Metal Hydrides: A Heterotrimetallic Nial2(Μ2-H)2 Catalyst For The Dearomatization Of N-Heterocycles, Edgardo De Leon, Fernando Gonzalez, Preetika Bauskar, Sergio Gonzalez-Eymard, David De Los Santos, Manar Shoshani

Chemistry Faculty Publications and Presentations

Identifying methods to modulate the reactivity of metal hydrides is lacking yet highly desirable given the role they play in a plethora of catalytic applications. Herein we report novel methodology to amplify the reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. Catalytic hydroboration of quinolines was dramatically altered by the addition of a secondary metal to bridge the Al–hydride species LAlH. Specifically, the addition of Ni(COD)2 led to the formation of novel heterotrimetallic species 1 which features Ni participating in 3-center bonding with sterically accessible Al–H species and exhibits catalytic hydroboration of sterically encumbered quinolines …

In Silico Binding Of 2-Aminocyclobutanones To Sars-Cov-2 Nsp13 Helicase And Demonstration Of Antiviral Activity, Thahani S. Habeeb Mohammad, Yash Gupta, Cory T. Reidl, Vlad Nicolaescu, Haley Gula, Ravi Durvasula, Prakasha Kempaiah, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

The landscape of viral strains and lineages of SARS-CoV-2 keeps changing and is currently dominated by Delta and Omicron variants. Members of the latest Omicron variants, including BA.1, are showing a high level of immune evasion, and Omicron has become a prominent variant circulating globally. In our search for versatile medicinal chemistry scaffolds, we prepared a library of substituted α-aminocyclobutanones from an α-aminocyclobutanone synthon (11). We performed an in silico screen of this actual chemical library as well as other virtual 2-aminocyclobutanone analogs against seven SARS-CoV-2 nonstructural proteins to identify potential drug leads against SARS-CoV-2, and more broadly against coronavirus …

Investigation Of Unexpected Purple Substance Extracted From Newsprint Paper [Poster], Raquel Wilhelm, Shoshanna Coon, Kirk Manfredi

Research in the Capitol

In an attempt to extract a green dye from newsprint advertisements, it was serendipitously discovered that a purple substance can be extracted from newsprint paper using methanol or acetic acid. Further investigations involving blank newsprint paper showed that the purple substance was a part of the paper itself rather than a component of the ink in the advertisements. Soxhlet extraction was used on the blank newspaper print to obtain the compound. Using different analytical instruments, characteristics of the compound can be determined such as the elemental composition, molar mass, and structure. The ultimate goal is to determine the compound and …

The Synthesis And Characterization Studies Of Modified Nucleobase In Pna And Dna, Gyeongsu Park

Electronic Thesis and Dissertation Repository

Nucleic acids have been extensively studied not only for their importance in biological systems as the medium of genetic information but also for their potential uses in therapeutic, diagnostic and other biological applications. As such, modified oligonucleotides and oligonucleotide analogues have drawn the attention of researchers from various disciplines. Modification of oligonucleotides can enhance their desired characteristics and engender unique properties, such as fluorescence, giving rise to a variety of applications. Peptide nucleic acid (PNA) is an oligonucleotide mimic with a pseudo-peptide backbone based on N-(2-aminoethyl)glycine that is renowned for high target binding affinity and resistance to enzyme degradation. …

Optimizing Course Offerings In A Science Department, Yu Kay Law

Academic Chairpersons Conference Proceedings

We will discuss how enrollment data and faculty/advisor input can be used to maximize schedule efficiency in course offerings and providing for student success. We will also discuss how best to monitor and rearrange course schedules in light of actual enrollment.