NC ACS Local Section Online Poster Session

NC ACS

The North Carolina Section of the American Chemical Society is proud to announce the news of our annual local section meeting on November 10th from 5pm to 7pm. This event is especially important for our section. We are requesting that you participate in this meeting to make it a great success. As part of our tradition, we will have a have a virtual poster session for our members and their students. We encourage participation of all undergraduates and graduate students.

More info: https://sites.google.com/site/northcarolinaacs/home

Filter displayed posters (49 tags)

show more… # 1 #CER 1 #CNS 1 #ChemEd 1 #ComputationalChemistry 1 #DIMS 1 #Drug 1 #GPCR 1 #Glycomics 1 #IR-MALDESI 1 #MRSA 1 #MRSAbiofilms 1 #MassSpectrometry 1 #ModellingMethods 1 #NonequilibriumThermodynamics 1 #Orphan 1 #VR 1 #Welbutrin,#Hydroxybupropion,#Synthesis,#charaterization 1 #antibiofilm 1 #antibiotics 1 #biochemical 1 #biofilminhibition 1 #biofilms 1 #capillary, 1 #chemistry 1 #colorchemistry 1 #computationalchemistry 1 #distanceEd 1 #echem 1 #evaporation, 1 #hydrogels, 1 #lab 1 #massspectrometry 1 #monosaccharide 1 #organicchemistry 1 #osmoticpumping, 1 #papermicrofluidics, 1 #representations 1 #sensing, 1 #solarfuels 1 #sweat, 1 #synergy 1 #synoxazolidinones 1 #wicking, 1 Discovery 1 Diseases 1 PCET 1 Receptor 1 assay 1

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Fused tetrahydroquinolines (THQ): privileged or promiscuous scaffolds?

Joel K. Annor-Gyamfi, Felix Nwogbo, Kenneth H. Pearce Jr, Stephen V. Frye, Alison D. Axtman

Abstract: Recently, three fused tetrahydroquinolines (THQ) emerged as hits from an ultra-high-throughput screening performed at Emory, in our search for small molecule chemical probes to modulate a specific protein target in Alzheimer’s Disease (AD) as part of our ongoing TREAT-AD project. These fused THQ are often identified as frequent screening hits in several bioassays and as such, their occurrences have sparked concerns about they being privileged or promiscuous scaffolds. Moreover, recent report has recognized these scaffolds as pan assay interference compounds (PAINS). These class of compounds appear to be selective, optimizable, and real however, they are found to be non-progressable, often after a significant waste of resources. Nikolakopoulos et al have also proposed that THQ could be oxidized in DMSO screening samples to form traces of quinoid-like structures, which could potentially interfere in a bioassay to give a false positive result. Herein, we demonstrate that the double bond in the cyclopentene ring of the fused THQ core system makes it susceptible to oxidative decomposition in solution to form traces of compounds that could interfere with several bioassays to give false positive results. Additionally, no activity was observed when the double bond was reduced.
Presented by: Joel K. Annor-Gyamfi
Institution: UNC-CH
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4-Alkoxyphenyl)glycinamides and Bioisosteric Oxadiazoles as Agonists for the Orphan Receptor GPR88

Md Toufiqur Rahman1, Ann M. Decker1, Tiffany L. Langston1, Weiya Ma2, Emmanuel Darcq2,3, Brigitte L. Kieffer2,3, and Chunyang Jin1*

Abstract: The G protein-coupled receptor (GPR88) is an orphan receptor highly expressed in the CNS, with particularly robust expression in the striatum throughout the dorsal and ventral areas. Genetic knockout and gene expression studies have suggested that GPR88 plays an important role in the regulation of dopaminergic system and is implicated in several CNS disorders such as Parkinson’s disease, schizophrenia, anxiety, and drug addiction. To date, pharmacological characterization of GPR88 has been limited due to the lack of potent and selective agonists and antagonists appropriate for CNS investigations. We have previously reported a synthetic small molecule 2- PCCA activates GPR88 through Gαi-coupled pathway. This poster presents the design, synthesis, and structure-activity relationship study of (4-alkoxyphenyl)glycinamides and bioisosteric oxadiazoles as GPR88 agonists with the goal of improving potency and drug-like properties.
Presented by: Md Toufiqur Rahman, PhD
Institution: RTI International
Other Affiliations: 1 Center for Drug Discovery, RTI International, RTP, NC, United States; 2 Douglas Mental Health Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada; 3 INSERM U1114, University of Strasbourg, Strasbourg, France
Hashtags: #Drug Discovery #Orphan Receptor #GPCR #CNS Diseases

Poster: COMPREHENSIVE EVALUATION OF AEROSOL CONSTITUENTS FROM JUUL VIRGINIA TOBACCO 5.0% USING NON-TARGETED ANALYSIS: LC-HRMS ANALYSIS OF E-VAPOR AEROSOLS, DATA ACQUISITION AND PROCESSING".

COMPREHENSIVE EVALUATION OF AEROSOL CONSTITUENTS FROM JUUL VIRGINIA TOBACCO 5.0% USING NON-TARGETED ANALYSIS: LC-HRMS ANALYSIS OF E-VAPOR AEROSOLS, DATA ACQUISITION AND PROCESSING".

Mark Crosswhite, Ph.D.

Abstract
Presented by: Mark Crosswhite, Ph.D.
Institution: Jaul Labs
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Analysis of representations of chemical structure in organic chemistry textbooks

Eshan Gurung, Robin Jacob and Maia Popova

Abstract: Chemists use a variety of representations (molecular formulas, chemical equations, molecular models, etc.) to visualize and communicate about chemical phenomena. Beside text, representations are the most prominent feature of chemistry textbooks; they determine the utility of textbooks in communicating and explaining chemistry content. No studies have analyzed types and functions of representations of chemical structure in organic chemistry textbooks yet. In this study, a detailed analysis of representations in three commonly used organic chemistry textbooks was conducted utilizing the chemistry triplet levels of thinking and functional taxonomy frameworks. Results indicate that although the three textbooks present similar content, they do it in different ways. All three textbooks utilize mostly symbolic representations and include very limited macroscopic representations even though students prefer representations that connect concepts to the real world. There were several representations with more than one function that may cause a learner to experience cognitive overload due to the cognitive demand of processing multiple representations with more than one function. Thus the findings from this study have implications for textbook developers on how to design multi-representational systems in textbooks to support deeper understanding of chemistry concepts.
Presented by: Dr. Eshan Gurung
Institution: University of North Carolina at Greensboro, Department of chemistry and biochemistry
Hashtags: #CER #representations

Chat with PresenterAvailable November 3, 2-4 pm

Bio-inspired Soft Multi-scale Capacitive Stress Sensor based on dual structure Liquid Metal Elastomer Foam"

Jiayi Yang, Ki Yoon Kwon, Shreyas Kanetkar

Abstract: Background: Capacitive stress sensors have attracted significant interest due to their high sensitivity and low energy consumption and have been used in a variety of applications, including healthcare monitoring[1], human-machine interfaces[2], and electronic textiles[3]. Capacitive stress sensors consist of a dielectric layer sandwiched between electrodes. The sensitivity and measurement range of capacitive sensors can be increased by decreasing or increasing the elastic modulus of the dielectric layer, which leads to a contradiction with each other. To solve this problem, a capacitive stress sensor based on dual-structure liquid metal elastomer foam (DSLMEF) is proposed. Inclusion of liquid metal in the elastomer is used to tune the dielectric constant of the mixed material[4], which was shown to give higher stress sensitivity[4].

Results: The DSLMEF is composed of a stiff elastomer slab (elastic modulus: ~655 kPa) and a soft liquid metal elastomer foam (LMEF, elastic modulus: ~7 kPa). Small stress (<10 kPa) only deforms the soft LMEF, and large stress (> 10 kPa) deforms the soft LMEF and the stiff elastomer slab at the same time. Using the DSLMEF as the dielectric layer, a capacitive stress sensor with high sensitivity (0.073 kPa-1), and a large stress measurement range (200 kPa) is demonstrated.

Conclusions: We report a bioinspired soft multi-scale capacitive stress sensor based on dual structure liquid metal elastomer foam. The fabrication process of the sensor is easy to implement, low cost, and environment friendly. Compared with other capacitive soft stress sensors, this work achieves a better combination of sensitivity and measurement range. In addition, the high elastic modulus and high energy loss coefficient of DSLMEF also mimic the dermis of human skin, which can cushion objects from stress and strain. The development of the bioinspired soft multi-scale capacitive stress sensor based on DSLMEF has important scientific value and practical significance.

References: 1. Gao, Y.; Yu, L.; Yeo, J. C.; Lim, C. T. Flexible Hybrid Sensors for Health Monitoring: Materials and Mechanisms to Render Wearability. Adv. Mater. 2020, 32 (15), e1902133, DOI: 10.1002/adma.201902133. 2. Hammock, M. L.; Chortos, A.; Tee, B. C.; Tok, J. B.; Bao, Z. 25th anniversary article: The evolution of electronic skin (e-skin): a brief history, design considerations, and recent progress. Adv. Mater. 2013, 25 (42), 5997-6038, DOI: 10.1002/adma.201302240. 3. Kim, D. C.; Shim, H. J.; Lee, W.; Koo, J. H.; Kim, D. H. Material-Based Approaches for the Fabrication of Stretchable Electronics. Adv. Mater. 2020, 32 (15), e1902743, DOI: 10.1002/adma.201902743. 4. Yang, J. Y.; Tang, D.; Ao, J. P.; Ghosh, T.; Neumann, T. V.; Zhang, D. G.; Piskarev, E.; Yu, T. T.; Truong, V. K.; Xie, K.; Lai, Y. C.; Li, Y.; Dickey, M. D. Ultrasoft Liquid Metal Elastomer Foams with Positive and Negative Piezopermittivity for Tactile Sensing. Adv. Funct. Mater. 2020, DOI: ARTN 2002611 10.1002/adfm.202002611.
Presented by: Shreyas Sanjay Kanetkar <sskanetk@ncsu.edu>
Institution: North Carolina State University
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Chat with PresenterAvailable November 9th, 2020 --- 1:00 pm to 2:30 pm Watch Presentation

Condensed Liquid Aerosol Particle Spray (CLAPS) Coupled to MS - a Novel On-Line Liquid Aerosol Analysis Technique

Nathaneal A. Park, Spencer E. Tilley, and Gary L. Glish

Abstract: Aerosols and their chemistry are consistently implicated as important factors in meteorological and climatological behavior as well as human health. However, methods for on-line aerosol analyses are often limited either in applicability or technical complexity. Condensed Liquid Aerosol Particle Spray (CLAPS) coupled to mass spectrometry is a new, on-line liquid aerosol sampling technique which avoids many of the disadvantages of traditional off-line sampling methods such as analyte aging or oxidation.
Presented by: Nathaneal Park <npark01@live.unc.edu>
Institution: UNC-CH
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Chat with PresenterAvailable November 10, 5-7 PM EST (as time allows)

Covalent Modification of Carbon Electrodes as a Platform for Probing Electrocatalytic CO2 Reduction

Brittany Huffman, Dr. Jillian Dempsey

Abstract: Achieving large-scale electrochemical conversion of solar energy into carbon neutral fuels requires immobilization of catalysts on photon-capturing material with a robust linkage. While surface immobilization of electrocatalysts is possible, the lack of accessible methods for analyzing surface-anchored species prevents rigorous quantification of their catalytic activity. I have developed a method for anchoring complexes on glassy carbon electrodes by electrochemically chlorinating the electrode surface and subsequently exposing the surface to a Grignard reagent. Experiments performed with ferrocene as a proof of concept demonstrate that this linkage is robust and the complex retains its electrochemical behavior. Preliminary results with a previously studied electrocatalyst for CO2 reduction, 5,5'dimethylbipyridine manganese fac-(CO)3 bromide, indicate that the this method is effective for tethering electrocatalysts to the electrode surface and that the complex retains electrocatalytic activity. Further analysis is ongoing to quantify turnover number, turnover frequency, and faradaic efficiency, which will allow me to provide quantitative comparison of catalytic performance for the surface anchored and homogenous analogs.
Presented by: Brittany Huffman <britth@live.unc.edu>
Institution: UNC-CH
Hashtags: #echem #solarfuels # PCET

Chat with PresenterAvailable November 10th, 5-7

Demonstration of Gluconeogenesis via Microbial Fuel Cell Technology

Katherine J. Mattena and Darryl K. Bing

Abstract: For the past two years, The Chemistry laboratory at Barton College has been studying the design and the applications of microbial fuel cells (MFCs) for the practical conversion of biomolecules (e.g. carbohydrates) into electricity. Work has been previously presented demonstrating how microbes – i.e. yeast and bacterial cells could metabolize carbohydrates of varying complexities to yield an electrical potential. In this project, the proteins, carnitine and creatine were placed into an MFC inoculated with E. coli and, over an eight (8) hour period, the maximum electrical potential for each protein was recorded. Carnitine generated a maximum potential of 329 mV (millivolts) while creatine was only able to generate a potential of 108 mV. It is the hypothesis of this lab that the potentials generated are dependent on the amino acid sequences of the proteins used. Amino acids classified as glucogenic are converted, by E. coli, into glucose via the process of gluconeogenesis. It is likely that the glucose created, and not the proteins, themselves, is being metabolized to yield electricity. The fact that an electrical potential can be visually observed indicates that gluconeogenesis is also being observed in real time.
Presented by: Katherine Mattena
Institution: Barton College
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Designing Selective Channels with a Chemical Ratchet Effect.

Chase Slowey and Zhiyue Lu

Abstract: In biology, the selective transportation of K+ ions through the passive channel KcsA has been extensively studied. Counterintuitively, the passive channel allows for large ions (“K+“) to go through while blocking the smaller ones (“Na+“). We have seen two proposed mechanisms to explain the selectivity of ion channels, focusing on two types of interaction affinity respectively: the ions’ solvation free energies and ions’ binding energies with the channel. Here we revisit transportation of particles via channels with the tools of stochastic thermodynamics and find a new kinetic ratcheting mechanism that allows us to selectively transport particles independent of a particle’s solvation free energy or its binding energy with the channel. Moreover, this new mechanism demonstrates a Maxwell’s-Demon-like channel where a particle can transport against its concentration gradient at the cost of entropy increase of the other type of particle. At the transition point to the demon-like phase, our channel achieves an infinitely high selectivity— allowing for one type of particle to go through while totally stopping the other type of particle. With our minimal model of selective transportation, we propose a new design principle for highly selective channels without the need for external energy sources.
Presented by: Chase Slowey
Institution: UNC Chapel Hill, Physical Chemistry
Hashtags: #ComputationalChemistry #NonequilibriumThermodynamics #ModellingMethods

Development of a Colorimetric Sensor for Detection of Methyl Salicylate During Man-In-Simulant-Test

Emma Woods, Tova N. Williams, R. Bryan Ormond

Abstract: Chemical Warfare Agents (CWAs) are recognized as one of the most deadly types of weapons of mass destruction. Consequently, personal protection equipment (PPE) has been developed to protect individuals from CWAs. The Man-In-Simulant-Test (MIST) is performed to evaluate effectiveness of PPE where subjects carry out exercises simulating normal activity experienced while wearing protective clothing. While in a chamber, the test subject wears Passive Adsorbent Dosimeters (PADs) on his/her skin which over time will absorb methyl salicylate (MeS), a CWA simulant. This process is time consuming and precautions must be taken to avoid cross-contamination. A colorimetric sensor to detect MeS can be an inexpensive, less time intensive, and more reliable process. Thus, this research focused on developing a sensor for measuring MeS dosage based on colorimetric measurements made using a handheld spectrophotometer. TLC plates were coated in ferric nitrate and then later exposed to MeS (10, 25, 50, 75and 100 mg/m3) in the MIST chamber. Every 5 minutes for 35 minutes total, 6 PADs were removed from the chamber and a colorimetric measurement was made on each of the 8 TLC plates. The PADs were extracted and analyzed via High Pressure Liquid Chromatography (HPLC) to determine the concentration of MeS absorbed, and these measurements were then compared to the colorimetric data measurements to see how well the overall color change (∆E) of the TLC plates from yellow to violet represented exposure to MeS. The colorimetric measurements were found to be agreeable.
Presented by: Emma Woods <ehwoods@ncsu.edu>
Institution: NC State University
Other Affiliations: Textile Protection and Comfort Center
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Chat with PresenterAvailable November 10th, 2020 from 4pm-8pm

Direct Analysis of Native N-Linked Glycans by IR-MALDESI Mass Spectrometry

Crystal L Pace, David C Muddiman

Abstract: Glycan analysis by mass spectrometry has rapidly progressed due to the interest in understanding the role of glycans in disease and tumor progression. Glycans are complex molecules that pose analytical challenges due to their isomeric compositions, labile character, and ionization preferences. This study sought to demonstrate infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) as a novel approach for the direct analysis of N-linked glycans. The glycoprotein bovine fetuin was chosen for this analysis as its glycome is well-characterized and heavily composed of sialylated glycans. Native N-linked glycans produced by enzymatic cleavage (via PNGase F) of bovine fetuin were analyzed directly by IR-MALDESI. In this study, we detected 12 N-linked glycans in negative mode, a signiﬁcant increase in the amount of underivatized glycans detected by other ionization sources. Importantly, all N-linked glycans detected contained at least one sialic acid residue, which are known to be labile. This work represents a critical ﬁrst step for N-linked glycan analysis by IR-MALDESI.
Presented by: Crystal L Pace <clgunth2@ncsu.edu>
Institution: NC State University
Hashtags: #IR-MALDESI #MassSpectrometry #Glycomics

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Distinguishing Unique Structures of Hexoses using Differential Ion Mobility Spectrometry-Mass Spectrometry".

Tiffany Crawford, Gary L. Glish

Abstract: In solution hexoses exist in an equilibrium of different structures. These structures consist of five membered furanose rings and six membered pyranose rings. For hexoses the pyranose form is the dominant form but some have significant percentages of furanose in solution. The pyranose and furanose structures are then divided into alpha anomers, where the hydroxyl group on the anomeric carbon is below the ring, and beta anomers where that hydroxyl group is above the ring. Distinguishing the furanose and pyranose structures is difficult by mass spectrometry. GC/MS and LC/ELSD methods exist for separation but require derivatization of the sample or specialized columns. Differential ion mobility spectrometry (DIMS) has been used in this work to separate different gas phase structures of hexoses. Water adduction in an ion trap mass spectrometer has previously been used to distinguish monosaccharide stereoisomers and can potentially help differentiate pyranoses and furanoses. This work aims to differentiate unique monosaccharide structures using DIMS-MS and identify them using collision-induced dissociation (CID), density functional theory (DFT) calculations, and water adduction to the lithiated hexose.
Presented by: Tiffany Crawford
Institution: UNC-CH
Hashtags: #monosaccharide #DIMS

Dyeing the World Green: A Study of How Water and Other Liquids Affect the Photodegradation of Disperse Dyes

Stephanie Atkinson, Ciera Cipriani, Melissa Pasquinelli, Nelson Vinueza

Abstract: Dyes that are commonly used in the textile industry possess a diazenyl functional group (R-N=N-R’) thus are called azo dyes. Previous studies indicate that photodegradation of these group of dyes causes the azo bond to break, resulting in toxic aromatic amine compounds, and these chemicals end up in wastewater and thus can lead to potential adverse health and environmental effects. More recent studies in our laboratories with a series of azo dyes performed by high-resolution mass spectrometry (HRMS) and density functional theory (DFT) indicate that the major photodegradation products were not based on the azo bond cleavage. In addition, the reactivities of these azo dyes for both the ground and excited states were determined in conjunction the cis-to-trans energy transitions. The reactivity of the studied azo dyes illustrated a trend in which the trans isomers are generally most susceptible to free radical attack at their amino end groups, while the cis isomers were more reactive at their azo group. However, when in a solution rather than on a fabric, such as in wastewater, this series of dyes is expected to have a different photodegradation mechanism. Thus, the goal of our work is to investigate the photodegradation mechanism of these dye molecules in a variety of solvent conditions. We will present on how modifying the medium in which azo dyes are found can allow for control of the location and mechanism of photodegradation, so that fewer harmful aromatic compounds are released into the environment. This research is important for understanding runoff from landfills that contain dyed textiles and the effect it has on wastewater, and thus reducing the hazardous effect that azo dyes could have on the environment and surrounding ecosystems.
Presented by: Stephanie Atkinson
Institution: NC State University, TECS Department
Other Affiliations: Goodnight Scholars Program, NC State Office of Undergraduate Research
Hashtags: #chemistry #colorchemistry #organicchemistry #massspectrometry #computationalchemistry

Electrochemical Impacts of TiOx Shells on Rutile TiO2 Nanorods

Milan Patel, Michael Mortelliti, Jillian Dempsey

Abstract: Rutile TiO2 shows promise for being used as a photoanode semiconductor in dye-sensitized photoelectrosynthesis cells (DSPECs), devices that use sunlight to drive the production of solar fuels. The addition of a TiO2 coating or shell onto a mesoporous nanocrystalline TiO2 photoanode substrate has been shown to improve device efficiency for water oxidation, yet little is known about why this change improves the performance of DSPECs. In this research, TiOx shells were deposited using atomic layer deposition onto rutile TiO2 nanorods and the electrochemical effects of the deposition were probed to help elucidate changes to the electronic structure induced by the shell. Rutile TiO2 was found to have a monoenergetic collection of deep trap states that is positive in potential to an exponential trap distribution in the band gap below the conduction band minimum. When increasing the TiOx shell thickness, the deep trap states of rutile TiO2 shifted to more positive potentials without changing the density of these states. In addition, the band gap of the material was found to decrease as shell thickness increased as quantified using diffuse reflectance spectroscopy. These results suggest the monoenergetic deep trap state population is not related to the surface of the nanorods. These findings may have implications for how charge transfer proceeds in these TiO2 films, and towards efforts of removing the deep trap states. Current research focuses on using (photo)electrochemical impedance spectroscopy to determine flatband potentials and rate constants of charge recombination to investigate how these physical parameters vary with TiOx shell thickness.
Presented by: Milan Patel
Institution: University of North Carolina at Chapel Hill, Department of Chemistry
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Hydroxybupropion: Synthesis and Characterization

Anita G. Minka†, Daniel J. Moats†, Jason A. Sampson†, Robert E. Lee†, James B. Kramer‡, Paige E. Heiple

Abstract: Bupropion, 1-(3-chlorophenyl)-2-[(1,1-dimethylethyl)amino]-1-propapone, Wellbutrin, is metabolized to hydroxybupropion (3), (2-hydroxy-2-(3-chlorophenyl)-3,5,5-trimethylmorpholine). While Bupropion is used to treat depression and smoking addiction as a dopamine and noradrenaline reuptake inhibitor, (3) is used for similar effect as noradrenaline reuptake inhibitor and nicotinic receptor antagonist.1 In this work, (3) was synthesized from 2-bromo-3’-chloropropiophenone (1) and 2-amino-2-methyl-1-propanol (2) via reflux in acetonitrile with 90% yield and characterized using 1H NMR, FTIR spectroscopy, and melting point.
Presented by: Anita G. Minka, Danial J. Moats, and Jason A. Sampson <rlee@bju.edu>
Institution: †Department of Chemistry and Physics, Bob Jones University
Other Affiliations: ‡Division of Chemistry, Cayman Chemical Company, Inc
Hashtags: #Welbutrin,#Hydroxybupropion,#Synthesis,#charaterization

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Hyperpolarization of common antifuganl agents with SABRE

Keilian MacCulloch, Patrick TomHon, Austin Browning, Evan Akeryod, Sören Lehmkuhl & Thomas Theis

Abstract: Signal amplification by reversible exchange (SABRE) is a robust and inexpensive way to enhance nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) signals using parahydrogen. With this relatively new technique, already a few common drugs and metabolites have been successfully polarized. Here, we present the polarization of large antifungal drugs and elicit the detailed hyperpolarization mechanisms for 1H and 15N nuclei. Hyperpolarizing common drugs is of rising interest due to their potential biomedical applications as MRI contrast agents and by enabling studies on protein dynamics at physiological concentrations. We optimize the polarization with respect to temperature and the polarization transfer field for 1H nuclei in the mT regime and for 15N nuclei in the µT regime, which provides detailed insights into exchange kinetics and spin evolution. This work broadens the SABRE substrate scope and provides mechanistic and kinetic insights into the hyperpolarization process.
Presented by: Keilian MacCulloch
Institution: NC State University
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Lab Inspections Reimagined: Formatting Feedback to Build a Culture of Safety

Melinda Box, Ciana Paye, Maria Gallardo-Williams

Abstract: Feedback’s format can have a significant impact on the outcome of an evaluation. Checklists are a common method used in health and safety inspections because the itemized structure standardizes an evaluator’s approach. However, this format is limited in its impact on recipients because it doesn’t convey prioritization within conditions deemed unacceptable, it varies in thoroughness of application, and it doesn’t provide guidance on how to solve issues cited. By contrast, prioritizing unstructured narrative comment, including positive citations that are specific and detailed can compensate for these limitations. Without this addition to the efficiency of checklists, inspectors miss the opportunity to reinforce actions already being performed and the opportunity to build on the foundation of existing skill and knowledge. This presentation brings together principles of management, evaluation tool design, and neurological science to illustrate how to leverage inspection feedback for a more significant impact on the culture of safety.
Presented by: Melinda Box (1), Ciana Paye(2), and Maria Gallardo-Williams(1)
Institution: North Carolina State University
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Mapping the topology of PbS nanocrystals

Melody L. Kessler, Jillian L. Dempsey

Abstract: PbS nanocrystals are predicted to undergo size-dependent shape changes, transitioning from octahedral to cuboctahedral morphology as nanocrystal size increases. Experimental evidence for size-dependent topology has been previously inferred from comparison of X-ray photoelectron spectroscopic measurements of Pb:S ratios with ideal morphologies or from Wulff ratios of nanocrystals extracted from high-resolution transmission electron microscopy images. Utilizing L-type ligand promoted Z-type ligand displacement as a tool to probe surface faceting, we correlate the number and reactivity of Z-type moieties with the surface structures of two different sizes of PbS NCs predicted to display distinct shapes (2.8 and 3.9 nm). Titration of N,N,N′,N′- tetramethylethane-1,2-diamine (TMEDA) into oleate-capped PbS nanocrystals liberates (κ2-TMEDA)Pb(OA)2 (OA = oleate), which is monitored via 1H nuclear magnetic resonance (NMR) spectroscopy. In light of prior reports of hydroxyl ligand binding to PbS NC surfaces, the stoichiometry of the displaced Z-type complex is investigated by combining oleate integrations from 1H NMR spectra with Pb quantitation from inductively coupled plasma mass spectrometry (ICP-MS). Displacement isotherms are employed to determine the number of binding sites and equilibrium constant values for two distributions of Z-type ligands, revealing site-specific heterogeneity on PbS nanocrystal surfaces. The distinct topological differences between small (2.8 nm) and large (3.9 nm) PbS nanocrystals provides explicit evidence for truncation at octahedral vertices, forming (100) facets as the nanocrystal diameter increases.
Presented by: Melody Kessler
Institution: University of North Carolina at Chapel Hill, Department of Chemistry
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Synthesizing Matrine Derivatives as Potential HIV Protease Inhibitors.

Shefali Srivastava

Abstract: HIV/AIDS is caused by the Human Immunodeficiency Virus. Its life cycle consists of six steps: infection, reception at the cell, integration into the host DNA, production of non-functional polypeptide, cleavage of polypeptide, and rebudding from the affected cell. The cleavage of the polypeptide chain is catalyzed by the action of HIV protease - a possible target for enzyme inhibition. Oxymatrine is an alkaloid compound extracted from Sophora flacescens, a Chinese herb, which has been shown to increase cardiac function by reducing the risk of heart failure and cardiac fibrosis. Through previous research, this compound has also shown inhibition of the HIV protease enzyme, making it a possible treatment for HIV-AIDS. Currently, there is great demand to synthesize chemical derivatives of matrine to make compounds that are more hydrophilic for drug testing. The purpose of this study was to explore the inhibition properties of matrinic acid derivatives on the HIV Protease enzyme. Over the course of this study, two derivatives of matrinic acid were synthesized: methyl ester of matrine and matrinamide. They were then tested on an HIV Protease assay to see if they inhibit the enzyme. Neither of the compounds showed any activity for inhibition. While they were both soluble in water, matrine methyl ester proved to be an activator of the HIV Protease enzyme, instead of an inhibitor. However, more research is required to purify the compounds synthesized. Further research can be conducted, using the ester derivative of matrine to activate similar cysteine-aspartic proteases to facilitate apoptosis in cancerous cells.
Presented by: Shefali Srivastava <ssrivastava@email.meredith.edu>
Institution: Meredith College
Other Affiliations: Wake Young Women's Leadership Academy
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Chat with PresenterAvailable Saturday, November 14, 5-6pm EST via Google meet

Mid and Late Career High School Science Teacher Retention in North Carolina Preliminary Findings

Dorothy Holley

Abstract: A descriptive, mixed methods study investigated factors that contribute to high school science teacher retention. Specifically, this study examined the impact of self-efficacy on the commitment of mid and late career high school science teachers in North Carolina. In addition, this study explored how teachers describe influences and cope with challenges that encourage them to remain in the teaching profession. Quantitative survey analysis (N=147) found subscales of self-efficacy – Personal Science Teaching and Outcome Expectancy - to be highly correlated to Overall Commitment and to each of four commitment subscales – Commitment to Students, Commitment to Teaching, Commitment to School, and Commitment to the Profession. Stronger commitments were found to Students and Teaching than to Schools and Profession. Qualitative content analysis of factors that have encouraged teachers to remain in the profession were 79.1% Personal, 7.5% Environmental and 13.4% Behavioral in nature; 80.9% of teachers in the survey described Relatedness – to student, parents, colleagues, or the community. Content analysis of coping strategies used during critical incidents were Modify Situation, Control Meaning, and Manage Stress; teachers described created new growth opportunities, 26% said they left the school. Specific to the American Chemical Society, teachers described relationships with community partners and professional development experiences as effective retention resources.
Presented by: Dorothy Holley
Institution: NC State University
Other Affiliations: West Johnston High School
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Poster: Organosulfates from aqueous reactions of isoprene-derived epoxydiols: Kinetics, mechanism, and effect of reaction environment on regioselectivity of sulfate addition

Organosulfates from aqueous reactions of isoprene-derived epoxydiols: Kinetics, mechanism, and effect of reaction environment on regioselectivity of sulfate addition

Sarah S. Petters, Tianqu Cui, Zhenfa Zhang, Avram Gold, V. Faye McNeill, Jason D. Surratt, and Barbara J. Turpin

Abstract: Atmospheric oxidation of isoprene yields large quantities of highly water-soluble isoprene epoxydiols (IEPOX) that partition into fogs, clouds, and wet aerosols. In aqueous aerosols, acid-catalyzed ring-opening of IEPOX followed by nucleophilic addition of inorganic sulfate or water forms organosulfates and 2-methyltetrols, respectively, contributing substantially to secondary organic aerosol (SOA). However, the fate of IEPOX in clouds, fogs and evaporating hydrometeors is not well understood. Here we investigate the rates, product branching ratios, and stereochemistry of organosulfates from reactions of dilute IEPOX (5 to 10 mM) under a range of sulfate concentrations (0.3 to 50 mM) and pH values (1.83-5.02) in order to better understand the fate of IEPOX in clouds and fogs. From these aqueous dark reactions of β-IEPOX isomers (trans- and cis-2-methyl-2,3-epoxybutane-1,4-diols), which are the predominant IEPOX isomers, products were identified and quantified using hydrophilic interaction liquid chromatography coupled to an electrospray ionization high-resolution quadrupole time-of-flight mass spectrometer operated in negative ion mode (HILIC/(–)ESI-HR-QTOFMS). We found that regiochemistry and stereochemistry were affected by pH and the tertiary methyltetrol sulfate (C5H12O7S) was promoted by increasing solution acidity. Furthermore, the rate constants for the reaction of IEPOX under cloud-relevant conditions are up to one order of magnitude lower than reported in the literature for aerosol-relevant conditions due to markedly different solution activity. Nevertheless, the contribution of cloud and fog water reactions to IEPOX SOA may be significant in cases of lower aqueous-phase pH (model estimate) or during droplet evaporation (not studied).
Presented by: Sarah S. Petters, PhD
Institution: University of North Carolina at Chapel Hill
Other Affiliations: Columbia University
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Osmotic-Capillary Principles for Microfluidic Pumping and Fluid Management for Sweat Sensing Devices.

Tamoghna Saha, Jennifer Fang, Sneha Mukherjee, Michael A. Daniele, Michael D. Dickey, Orlin D. Velev

Abstract: Sweat is an important biofluid for monitoring individuals’ health as it contains a number of essential biomarkers. However, sampling sweat for analysis still remains challenging as most of the commercially available sweat sensing devices are either invasive in nature or work only under active perspiration. These devices may not function under low-sweating conditions and are incapable of deriving information in sweat from sedentary subjects. We demonstrate a new principle for the design of flexible and wearable devices, which are capable of extracting sweat under both sedentary and actively perspiring conditions using osmotic pressure difference for pumping, and evaporation for liquid disposal. The device is composed of silicone, polyacrylamide hydrogel patch, and paper microfluidic conduit with a site of evaporation at the end (evaporation pad). The hydrogel is equilibrated with glycerin, glucose, or NaCl solution to build up the desired osmotic strength. We investigate their operation using dye (a model biomarker). In-vitro testing with gelatin-based model skin platform revealed that both glucose and glycerin infused gels facilitate high accumulation on the evaporation pad, with glucose being having the highest driving pressure. Parameters including the dimensions of the paper channel, hydrogel area and paper porosity also affect the cumulative dye collection. Human trials using prototype devices containing gels infused with glucose show potential to extract sweat and analyze it for lactate under both resting and non-resting conditions within a period of two hours. This sweat sampling concept can be integrated with continuous sensing using enzymatic electrochemical sensors. We chose lactate as a concept demonstrator, as sweat appears to be much more informative medium for lactate quantification than blood. The ability to measure lactate is interesting for monitoring metabolism and oxidative stress levels in athletes and military personnel.
Presented by: Tamoghna Saha
Institution: NCSU
Hashtags: #papermicrofluidics, #sweat, #sensing, #hydrogels, #osmoticpumping, #evaporation, #capillary, #wicking, #biochemical assay

Chat with PresenterAvailable November 10th, 5-7 pm Watch Presentation

Stick it to CO2 Reduction Providing the Molecular Framework to Measure Electrode Bound Catalytic CO2 Reduction"

Nehemiah Stewart, Brittany Huffman, Jillian Dempsey

Abstract: Release of CO2 from fossil fuel consumption has become a growing concern in recent years, with every ecosystem feeling its effects. There has been significant research in recent years on the performance of molecular electrocatalysts for CO2 reduction, because they are highly tunable and can be optimized. Unfortunately, molecular catalysts are difficult to recycle, and the majority of the catalyst placed in solution is effectively inactive as it is far from the electrode surface where reduction takes place. My group aims to mitigate these complications by covalently linking known molecular catalysts directly to the electrode surface, wherein it can immediately reduce CO2 that diffuses nearby. Towards this goal, I will study a manganese catalyst supported by a bipyridine ligand which will be covalently attached to a glassy carbon electrode. I predict that once attached to the surface, unproductive dimerization in solution will be inhibited, and we will be able to achieve higher catalytic efficiencies by significant enhancement of the local catalyst concentration near the electrode. Moreover, the proposed covalent immobilization of the catalyst to the electrode should impart higher stability in comparison to typically used immobilization strategies like absorption. This project will take a large step in the use of renewable energy sources by providing platform to begin integrating this well practiced CO2 reduction outside of the laboratory and into physical devices.
Presented by: Nehemiah Stewart
Institution: The University of North Carolina at Chapel Hill
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Synthesis of 2,2-Difluorinated-[6]-gingerol using selective C-C bond cleavage.

Bi Youan Eric Tra and Dr. Eun Hoo Kim

Abstract: Fluorinated organic compounds are gaining prominence in number of research fields such as drug modifications, biomedical imaging and material science. A concise approach to synthesize [6]-2,2-difluorogingerol compound 3 via mild release of trifluoroacetate is studied. The target potentially possesses antipyretic, cardiotonic, analgesic and gastroprotective and antihepatotoxic activities. The synthetic approach would demonstrate the flexibility of this methodology and its potential for synthesizing a variety of natural and unnatural compounds. Biological activities of both (R)- and (S)-isomers will be tested.
Presented by: Bi Youan Eric Tra
Institution: Methodist University�
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Chat with PresenterAvailable November 10th 5-9 pm Watch Presentation

Synthetic Methods Towards Biologically Active 4-oxazolidinones".

Bram H. Frohock, Jessica M. Gilbertie, Jennifer C. Daiker, Lauren V. Schnabel and Joshua G. Pierce

Abstract: The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative approaches to treatment so as to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5‐benzylidene‐4‐oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms, and, in combination with common antibiotics, are able to significantly reduce the bacterial load in a robust collagen‐matrix model of biofilm infection.
Presented by: Bram Frohock
Institution: North Carolina State University, College of Sciences, Department of Chemistry
Hashtags: #biofilms #antibiotics #biofilminhibition #synoxazolidinones #antibiofilm #MRSA #MRSAbiofilms #synergy

Chat with PresenterAvailable November 2nd, 2-3:55 pm EST November 3rd 10 am -12 pm EST

Using Virtual Reality to Teach Organic Chemistry Labs Remotely: Beyond the Pandemic

Maria Gallardo-Williams

Abstract: Using Virtual Reality (VR) in educational settings is becoming increasingly popular. Prior to the COVID-19 pandemic, we became interested in the feasibility of replacing a traditional organic chemistry lab experiment with a VR experience. The resulting first-person VR experiences are immersive and realistic, with a teaching assistant guiding the user along the steps required to complete the experiment, including feedback as needed. The VR experiences were developed in WondaVR with selections made using gaze navigation. The resulting experiences have been used to replace in-person labs since late Spring 2020. Students taking the lab in this fashion were asked to complete an evaluation instrument (Meaningful Learning in the Laboratory Instrument, MLLI) to assess their expectations and satisfaction with the experience. Results suggest that students in virtual reality organic chemistry labs had very similar responses to the cognitive items in the pre- and post- MLLI surveys to students that took in-person labs. However, students in virtual reality labs had higher average post-scores in a number of questions from the affective and cognitive/affective categories
Presented by: Maria Gallardo-Williams
Institution: North Carolina State University
Hashtags: #ChemEd #VR #distanceEd #lab

Chat with PresenterAvailable November 10 5-7pm