Chemistry Commons^™

Moss Biomonitoring And Isotopic Signatures Reveal Aviation Fuel As Local Lead Source Near Oregon Airports, Oluwaseyi E. Aderinboye, Alyssa E. Shiel, Lauren Stalford, Christina J. Murphy, Dean B. Atkinson

Chemistry Faculty Publications and Presentations

Lead emissions from piston-engine aircraft using leaded aviation gasoline (avgas) remain a significant source of environmental contamination near regional airports, posing potential health risks to nearby communities. Passive biomonitoring using the epiphytic moss Orthotrichum lyellii was combined with lead isotope fingerprinting to quantify lead concentrations and distinguish between legacy leaded gasoline and current avgas emissions near Hillsboro and Troutdale airports in Oregon. Here we show that lead levels are elevated by up to 50 times the rural background near airports, with isotopic signatures confirming avgas as a dominant local source. These findings indicate that avgas use contributes substantially to environmental …

Evaluating Acridones As Novel Therapeutics For Human Babesiosis, Pratap Vydyam, Elizabeth Zhang, Papireddy Kancharla, Rozalia A. Dodean, Jane X. Kelly

Chemistry Faculty Publications and Presentations

Human babesiosis is an emerging tick-borne disease caused by Babesia parasites, most notably Babesia microti and Babesia duncani in North America and Babesia divergens in Europe. Infections can be severe or persistent or relapse despite treatment, and current therapeutic options remain limited, underscoring the urgent need for new and effective treatment options. Acridone derivatives originally developed as potent antimalarial agents against multiple life cycle stages of the malaria parasites were evaluated for their antibabesial activity using continuous in vitro culture systems of B. duncani and B. divergens. Lead candidates were assessed for selectivity against human cell lines to establish preliminary …

Toxicity, Chemistry, And Public Health Relevance Of Emerging Nicotine Analog Vapes, Pods, And Pouches., Rhea Raghu, Mohana Sengupta, Karen Lin, Felix Effah, Robert M. Strongin, Irfan Rahman

Chemistry Faculty Publications and Presentations

Electronic nicotine delivery system manufacturers, such as Charlie's Holdings Inc., ECBlend, Outlaw, and NicRiver, have recently introduced nicotine analogs, such as 6-methyl nicotine, 6-MN ("Metatine"), and nicotinamide, NA ("Nixamide," "Nixodine," or "Nixotin-free base and salt") in products to circumvent the U.S. FDA's premarket tobacco product application (PMTA) requirements. Marketed as "tobacco-free," "PMTA-exempt," or "FDA-approved," these compounds now appear in oral nicotine pouches and disposable bars/vapes from brands such as Outlaw Dip, Kumi-Six, SBX, Katchmi, and Spree Bar under proprietary labels including "NoNic6," "Metatine," or "NIC-SAFE." These products often mimic the appeal of conventional nicotine delivery systems, with extensive use of …

Analysis Of Novel Cannabis Products Labeled As Containing Thc-Jd, Kaelas R. Munger, Carlton C. B. Bone, Killian M. Anreise, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Objective:

THC-JD (tetrahydrocannabioctyl) is a semi-synthetic cannabinoid with an eight-carbon C3 side chain, present in only trace amounts in hemp, requiring synthesis for commercial use. It has been promoted as potentially 19 times more potent than delta-9-THC, consistent with enhanced CB1 receptor affinities for cannabinoids with 7-8 carbon C3 side chains. While one peer-reviewed report identified THC-JD (tetrahydrocannabioctyl) in Japanese online products, an anecdotal report from the U.S. suggests mislabeling. Method: To inform regulatory efforts and consumer awareness and to address these discrepancies, this study chemically analyzed five U.S. commercial cannabis vape products marketed as containing THC-JD. Results: Utilizing GC-MS …

Designing Novel Bisquinoline Antimalarials From Historical 4-Aminoquinolines To Combat Drug-Resistant Malaria, Mason J. Handford, Yuexin Li, Terry Riscoe, Xiaowei Zhang, Jane X. Kelly, Michael K. Riscoe

Chemistry Faculty Publications and Presentations

Plasmodium falciparum, the deadliest causative agent of malaria, continues to evade eradication efforts through widespread drug resistance. The recent development of ADC-028, a 4-aminoquinoline antimalarial with excellent activity and pharmacokinetic properties, prompted the investigation of bisquinoline analogs featuring similar structural motifs. Here, we describe a structure-activity relationship study that guided the optimization of compounds with key features, including the 4-anilinoquinoline core and diverse bridging linkers. Several analogs exhibited potent in vitro activity (IC50 < 20 nM) against both drug-sensitive and multidrug-resistant P. falciparum strains, while maintaining favorable cytotoxicity profiles. Among them, 25 demonstrated improved intrinsic metabolic stability (t1/2 = 121 min) and potent in vivo efficacy (ED50 = 0.32 mg/kg/day), achieving complete curative protection at a reduced dose compared to ADC-028. While 25 showed moderately reduced oral bioavailability (F = 43%) and a shorter half-life (T1/2 = 27.2 h) relative to ADC-028, its enhanced in vivo efficacy underscores its therapeutic potential. This work highlights a promising path forward in developing antimalarials that retain the efficacy of legacy compounds while overcoming modern resistance mechanisms.

Nonenzymatic Glucose Biosensor Based On Selective Reduction Of Silver Ions, Maryam Sarlak, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

A nonenzymatic conductivity-based glucose biosensor, reported here, designed for potential noninvasive measurement in accessible biofluids such as saliva, sweat, and tears. The sensor exploits a classic Tollens’ silvering process that deposits metallic silver on a sensitized surface via a quantitative, selective reduction of silver ions by glucose. Of the two surface sensitization methods used, the self-assembled bifunctional thiol/silane surfactant yields a more stable and sensitive sensor than tin(II) chloride. The conductometric sensor consists of two spiral interdigitated silver electrodes fabricated by lithography and wet etching. The sensor impedance changes after selective metallic silver deposition between the electrodes. The sensor exhibits …

Selective Reversal Of Cu-Amyloid Aggregation Monitored In Real Time By Fluorescence Anisotropy: Ni-Bme-Dach Vs Edta Benchmarks, Alyssa N. Schroeder, Eleanor K. Adams, Dane C. Frost, Erica Lopez, Jennie R. Giacomini, Marilyn R. Mackiewicz

Chemistry Faculty Publications and Presentations

Metal dyshomeostasis, particularly involving Cu2+, is increasingly recognized as a key contributor to amyloid-β (Aβ) aggregation and neurotoxicity in Alzheimer’s disease, motivating the development of chelators capable of selectively disrupting pathogenic metal-Aβ interactions without perturbing essential biological metals. Here, we employ steady-state fluorescence anisotropy as a real-time probe of TAMRA-Aβ1–42 rotational mobility to quantify metal-induced aggregation and its reversibility by two chelators with distinct selectivities: EDTA, a broad-spectrum benchmark, and Ni-bme-dach, a sulfur-rich metallodithiolate with high Cu affinity. Cu2+ induces the most significant increases in anisotropy, consistent with rapid formation of large nanoscale aggregates, while Fe3+ produces moderate aggregation and …

The Gut Microbiota Shapes The Human And Murine Breath Volatilome, Ariel J. Hernandez-Leyva, Amalia Z. Berna, Maggie H. Bui, Yang Liu, Anne L. Rosen, Michael A. Lint, Samantha A. Whiteside, Natalia Jaeger, Nikhilesh Joardar, Wentai Luo, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

The gut microbiota is crucial to health, yet implementation of microbiota-based therapeutics is limited by the lack of rapid diagnostics. We hypothesize that breath contains gut microbe-derived volatile organic compounds (VOCs) reflecting microbiota composition and metabolism. In healthy children, we found that breath VOC composition (or volatilome), assessed by gas chromatography-mass spectrometry, correlates with gut microbiome composition and function. By capturing exhaled breath from human-stool-colonized and monocolonized gnotobiotic mice, we profiled breath VOCs and discovered that murine breath is also significantly influenced by the gut microbiome. VOCs from cultured gut microbes were identified in vivo in monocolonized gnotobiotic colonized mice. …

Using The Epic (Exposure, Persuasion, Identification, And Commitment) To Develop A Measure Of Student Buy-In To Laboratory Learning Goals, Elizabeth Blanche Vaughan, A. Montoya-Cowan, Jack Barbera

Chemistry Faculty Publications and Presentations

Buy-in has been described as the series of judgements students make when deciding to engage with a pedagogical practice. Buy-in to pedagogical practices is known to have a meaningful impact on students’ engagement in learning environments, making it a construct of interest for researchers and practitioners. This study develops a measure of student buy-in to faculty defined laboratory learning goals by adapting an existing measure which operationalizes the construct in terms of Exposure, Persuasion, Identification, and Commitment (EPIC). The adapted measure presented in this study, deemed the EPIC-LaG (Laboratory Goals), was developed using learning goals for general and organic chemistry …

The Lewis Basicity Of Amines On The Legault Iodonium Lewis Acidity Scale., Soocheta Jha, Souradeep Basu, Madison Bob, David R. Stuart

Chemistry Faculty Publications and Presentations

Diaryliodonium-amine complexes are proposed as key intermediates in metal-free C-N coupling reactions. Herein, H NMR titration is used to quantify association constants () between diaryliodonium triflates and synthetically relevant amines from which the amine Lewis basicity (LB) parameter is calculated. Compared to anionic Lewis bases, distinct solvent effects are observed.

Potent Acridone Antimalarial Against All Three Life Stages Of Plasmodium, Papireddy Kancharla, Rozalia A. Dodean, Yuexin Li, Xiaowei Zhang, Sean Kelly, Jordan Charlton, Angley Binauhan, Laurize Garcia, Diana Caridha, Jane X. Kelly, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

New antimalarial therapeutics ideally should target all three major life cycle stages. Here we present an acridone antimalarial chemotype that is potent against blood, liver, and mosquito stages of malaria parasites, with the potential for single-dose cure of bloodstream infections, radical cure of liver infections, and blocking of transmission to mosquitoes. Attributes of lead candidate T111 include potent in vitro activity against cultured parasites, ex vivo activity against clinical isolates, oral single dose cure in an asexual blood stage rodent model, inhibition of sexual blood stage parasites, activity against relapsing parasites in non-human primate liver cells, prevention of parasite development …

Cannabis Concentrate Vaping Chemistry, Kaelas R. Munger, Killian M. Anreise, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Background:

This review article addresses the vaping chemistry of manufactured cannabis concentrates—a topic that remains under-researched despite the widespread availability and growing popularity of these products. Given their current prevalence and the fact that many of the findings discussed herein are from early-stage investigations, further research is essential to fully assess the public health risks associated with concentrate use. The purpose of this article is to help begin to bridge this knowledge gap by outlining the technical challenges of studying cannabis concentrates and to present evidence-based data concerning toxicant exposures as a foundation for future investigations.

Methods:

A search of …

Identifying Antimalarials That Disrupt Malaria Parasite Transmission When Fed To The Mosquito, Sarah N. Farrell, Anton Cozijnsen, Vanessa Mollard, Papireddy Kancharla, Rozalia A. Dodean, Jane X. Kelly, Geoffrey I. Mcfadden, Christopher D. Goodman

Chemistry Faculty Publications and Presentations

A decade-long decline in malaria cases has plateaued, primarily due to parasite drug resistance and mosquito resistance to insecticides used in bed nets and indoor residual spraying. Here, we explore the innovative control strategy targeting Plasmodium with antimalarials during the mosquito stages. This strategy has the potential to reduce the risk of resistance emerging because a relatively small population of parasites within the mosquito is subject to selection. After validating mosquito feeding strategies, we screened a range of parasiticidal compounds by feeding them to mosquitoes already infected with mouse malaria (P. berghei). Three antimalarials showed activity against P. berghei in …

Access To Arynes From Arenes Via Net Dehydrogenation: Scope, Synthetic Applications And Mechanistic Analysis, Riley A. Roberts, Bryan E. Metze, Nicole Javaly, Theresa M. Mccormick, David R. Stuart

Chemistry Faculty Publications and Presentations

Arynes undergo a wide range of chemical transformations making them versatile reactive intermediates for organic synthesis. Access to arynes has long been dominated by pre-functionalised reagents, e.g., the venerable o-trimethylsilylaryl triflates. However, a move toward developing methods to access arynes that are both mild and efficient has prompted research into aryl “onium” aryne precursors. Here, we leverage aryl “onium” species as in situ or isolated intermediates in a net dehydrogenation of simple arenes as a novel and efficient way to access arynes. We describe a unified strategy in which two different tactics are employed to access diversely substituted …

Understanding Anionic Hyperporphyrins: Tddft Calculations On Peripherally Deprotonated Meso-Tetrakis(4-Hydroxyphenyl)Porphyrin., Jeanet Conradie, Carl C. Wamser, Abhik Ghosh

Chemistry Faculty Publications and Presentations

Presented herein is a DFT/TDDFT study of -tetrakis(4-hydroxyphenyl)porphyrin (H[THPP]) and its Meso-deprotonated tetraanionic form; the latter was modeled as both a free tetraanion and with various counterions. Based on our calculations, the experimentally observed hyperporphyrin spectra are attributed to an admixture of phenol/phenoxide character into the a-type HOMO of tetraphenylporphyrin. The admixture results in an elevation of the orbital energy of the HOMO in relation to other frontier orbitals, which accounts for the observed spectral redshifts. The calculations underscore differences in the performance of different exchange-correlation functionals. Thus, while the popular hybrid functional B3LYP greatly exaggerates the redshift of …

Increased Thermal Stability And Retained Antibacterial Properties In A Sulbactam And Amantadine Salt: Towards Effective Antibacterial-Antiviral Combination Therapies, Josephine Bicknell, Ivan Bondarenko, Alice Colatrella, Elani J. Cabrera-Vega, Jesus Daniel Loya, Delbert S. Botes, Jay L. Mellies, Gonzalo Campillo-Alvarado

Chemistry Faculty Publications and Presentations

A clinically relevant multidrug solid comprising sulbactam (β-lactamase inhibitor) and amantadine (antiviral) displays enhanced thermal stability and sustained antibacterial activity compared to starting materials.

We describe the formation of a multidrug salt comprising sulbactam (SUL, β-lactamase inhibitor) and amantadine (AMNH, antiviral). Physicochemical investigation of the SUL·AMNH salt revealed enhanced thermal stability compared to pristine starting materials. In vitro studies found that salt formation in SUL·AMNH does not disrupt antibacterial activity against model organisms Escherichia coli and Staphylococcus epidermidis. To our knowledge, we show the first β-lactamase inhibitor-antiviral salt where both components have been approved by the U.S. Food and Drug …

Aars Online: A Collaborative Database On The Structure, Function, And Evolution Of The Aminoacyl-Trna Synthetases, Jordan Douglas, Haissi Cui, John J. Perona, Oscar Vargas-Rodriguez, Henna Tyynismaa, Claudia Alvarez Carreno, Jiqiang Ling, Lluis Ribas De Pouplana, Xiang-Lei Yang, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

The aminoacyl-tRNA synthetases (aaRS) are a large group of enzymes that implement the genetic code in all known biological systems. They attach amino acids to their cognate tRNAs, moonlight in various translational and non-translational activities beyond aminoacylation, and are linked to many genetic disorders. The aaRS have a subtle ontology characterized by structural and functional idiosyncrasies that vary from organism to organism, and protein to protein. Across the tree of life, the 22 coded amino acids are handled by 16 evolutionary families of Class I aaRS and 21 families of Class II aaRS. We introduce AARS Online, an interactive Wikipedia-like …

Investigating The Learning Goals And Expectations Of Laboratory Coordinators, Graduate Teaching Assistants, And Students In General And Organic Chemistry Laboratory Courses, Elizabeth Blanche Vaughan, A. Montoya-Cowan, Christine Kim, Alexandra Stephens, Osie Hamilton, Jack Barbera

Chemistry Faculty Publications and Presentations

As chemistry education researchers and practitioners continue to investigate and improve undergraduate laboratory courses, it is necessary to consider the perspectives held by each of the stakeholders who are directly involved in these courses, including laboratory coordinators, graduate teaching assistants, and students. This study sought to qualitatively investigate the learning goals and expectations held by laboratory coordinators, graduate teaching assistants (GTAs), and students for general and organic chemistry laboratory courses at a single institution. This was completed through the collection and analysis of semistructured interview data from laboratory coordinators and GTAs and open-ended written responses from students. Results indicated that …

Polymorphism Control Of Polyethylene Terephthalate (Pet) Degradation Product Via Mechanochemistry Leads To Accelerated Microbial Degradation, Deepika Shingwekar, Nicholas Lutz, Delbert S. Botes, Elani J. Cabrera-Vega, Gonzalo Campillo-Alvarado, Jay L. Mellies, Jesus Daniel Loya

Chemistry Faculty Publications and Presentations

Here, we optimized a chemo-microbial degradation of polyethylene terephthalate. Developed a path to mechanochemically interconvert between BHET polymorphs and established that BHET polymorphism influences bacterial biodegradation rate.

Investigating Students' Expectations And Engagement In General And Organic Chemistry Laboratory Courses, Elizabeth B. Vaughan, Saraswathi Tummuru, Jack Barbera

Chemistry Faculty Publications and Presentations

Students’ expectations for their laboratory coursework are theorized to have an impact on their learning experiences and behaviors, such as engagement. Before students’ expectations and engagement can be explored in different types of undergraduate chemistry laboratory courses, appropriate measures of these constructs must be identified, and evidence of validity and reliability for the data collected with these instruments must be investigated. This study collected evidence related to response process validity, internal structure validity, and single administration reliability for version 2 of the Meaningful Learning in the Laboratory Instrument (MLLIv2) and a measure of student engagement in the undergraduate chemistry laboratory. …

Effects Of Spontaneous Curvature On Interfacial Adsorption And Collapse Of Phospholipid Monolayers, Bret A. Brandner, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

To function effectively, pulmonary surfactant must adsorb rapidly to the alveolar air/water interface but avoid collapse from the surface when compressed to high interfacial densities. Prior studies show that phospholipids in the cylindrical monolayers of the inverse hexagonal (HII) phase adsorb quickly. The monolayers have negative curvature, defined by the concave shape of the hydrophilic face. Formation of the HII structures, however, involves significant disruption of chain-packing. Samples with significant spontaneous curvature, formed in the absence of applied force, may nonetheless have lamellar structures that optimize chain-packing. The experiments here tested whether planar lamellar bilayers formed by phospholipids with negative …

Toxicity Of Waterpipe Tobacco Smoking: The Role Of Flavors, Sweeteners, Humectants, And Charcoal, Nada O F Kassem, Robert M. Strongin, Andrea M. Stroup, Marielle C. Brinkman, Ahmad El-Hellani, Hanno C. Erythropel, Arash Etemadi, Maciej L. Goniewicz, Eleanore G. Hansen, Noura O. Kassem, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Waterpipe tobacco (WPT) smoking is a public health concern, particularly among youth and young adults. The global spread of WPT use has surged since the introduction of pre-packaged flavored and sweetened WPT, which is widely marketed as a safer tobacco alternative. Besides flavorants and sugars, WPT additives include humectants, which enhance the moisture and sweetness of WPT, act as solvents for flavors, and impart smoothness to the smoke, thus increasing appeal to users. In the United States (U.S.), unlike cigarette tobacco flavoring (with the exception of menthol), there is no FDA product standard or policy in place prohibiting sales of …

A Comparison Of Structure, Bonding And Non-Covalent Interactions Of Aryl Halide And Diarylhalonium Halogen-Bond Donors, Nicole Javaly, Theresa M. Mccormick, David R. Stuart

Chemistry Faculty Publications and Presentations

Halogen bonding permeates many areas of chemistry. A wide range of halogen-bond donors including neutral, cationic, monovalent, and hypervalent have been developed and studied. In this work we used density functional theory (DFT), natural bond orbital (NBO) theory, and quantum theory of atoms in molecules (QTAIM) to analyze aryl halogen-bond donors that are neutral, cationic, monovalent and hypervalent and in each series we include the halogens Cl, Br, I, and At. Within this diverse set of halogen-bond donors, we have found trends that relate halogen bond length with the van der Waals radii of the halogen and the non-covalent or …

Mechanistic Rationale For Ketene Formation During Dabbing And Vaping, Kaelas R. Munger, Killian M. Anreise, Robert P. Jensen, David H. Peyton, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Ketene is one of the most toxic vaping emissions identified to date. However, its high reactivity renders it relatively challenging to identify. In addition, certain theoretical studies have shown that realistic vaping temperature settings may betoo low to produce ketene. Each of these issues is addressed herein. First, an isotopically labeled acetate precursor is used for the identification of ketene with enhanced rigor in vaped aerosols. Second, discrepancies between theoretical and experimental findings are explained by accounting for the effects of aerobic (experimental) versus anaerobic (simulated and theoretical) pyrolysis conditions. This finding is also relevant to explaining the relatively low-temperature …

Complete Genome Sequence Of Strain Jm503a, A Genetically Tractable Dental Abscess Clinical Isolate, Dustin L. Higashi, Anh Nguyen, Hua Qin, Christina Borland, Elizabeth A. Palmer, Nicolas Biais, Jens Kreth, Justin Merritt

Chemistry Faculty Publications and Presentations

Parvimonas micra is a pathobiont of humans that is often found in abundance at sites of mucosal inflammation as well as within malignant tumors. Here, we report the complete genome sequence of P. micra strain JM503A, which is a genetically tractable clinical isolate derived from a human odontogenic abscess specimen.

A Review Of The Toxicity Of Ingredients In E-Cigarettes, Including Those Ingredients Having The Fda's "Generally Recognized As Safe (Gras)" Regulatory Status For Use In Food., Nada O F Kassem, Robert M. Strongin, Andrea M. Stroup, Marielle C. Brinkman, Ahmad El-Hellani, Hanno C. Erythropel, Arash Etemadi, Vernat Exil, David H. Peyton, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Some firms and marketers of electronic cigarettes (e-cigarettes; a type of electronic nicotine delivery system (ENDS)) and refill liquids (e-liquids) have made claims about the safety of ingredients used in their products based on the term "GRAS or Generally Recognized As Safe" (GRAS). However, GRAS is a provision within the definition of a food additive under section 201(s) (21 U.S.C. 321(s)) of the U.S. Federal Food Drug and Cosmetic Act (FD&C Act). Food additives and GRAS substances are by the FD&C Act definition intended for use in food, thus safety is based on oral consumption; the term GRAS cannot serve …

Tripeptide-Assisted Gold Nanocluster Formation For Fe3+ And Cu2+ Sensing, Jonghae Youn, Peiyuan Kang, Justin Crowe, Caleb Thornsbury, Peter Kim, Zhenpeng Qin, Jiyong Lee

Chemistry Faculty Publications and Presentations

Fluorescent gold nanoclusters (AuNCs) have shown promise as metal ion sensors. Further research into surface ligands is crucial for developing sensors that are both selective and sensitive. Here, we designed simple tripeptides to form fluorescent AuNCs, capitalizing on tyrosine’s reduction capability under alkaline conditions. We investigated tyrosine’s role in both forming AuNCs and sensing metal ions. Two tripeptides, tyrosine–cysteine–tyrosine (YCY) and serine–cysteine–tyrosine (SCY), were used to form AuNCs. YCY peptides produced AuNCs with blue and red fluorescence, while SCY peptides produced blue-emitting AuNCs. The blue fluorescence of YCY- and SCY-AuNCs was selectively quenched by Fe3+ and Cu2+, whereas red-emitting YCY-AuNC …

Chemical And Physiological Interactions Between E-Liquid Constituents: Cause For Concern?, Robert M. Strongin, Eva Sharma, Hanno C. Erythropel, Nada O F Kassem, Alexandra Noël, D H. Peyton, Irfan Rahman

Chemistry Faculty Publications and Presentations

Studies of Electronic Nicotine Delivery Systems (ENDS) toxicity have largely focused on individual components such as flavour additives, base e-liquid ingredients (propylene glycol, glycerol), device characteristics (eg, model, components, wattage), use behaviour, etc. However, vaping involves inhalation of chemical mixtures and interactions between compounds can occur that can lead to different toxicities than toxicity of the individual components. Methods based on the additive toxicity of individual chemical components to estimate the health risks of complex mixtures can result in the overestimation or underestimation of exposure risks, since interactions between components are under-investigated. In the case of ENDS, the potential of …

Comparison Of Emissions Across Tobacco Products: A Slippery Slope In Tobacco Control, Ahmad El-Hellani, Ayomipo Adeniji, Hanno C. Erythropel, Thomas Lamb, Qixin Wang, Vladimir Mikheev, Robert Strongin, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

In this narrative review, we highlight the challenges of comparing emissions from different tobacco products under controlled laboratory settings (using smoking/ vaping machines). We focus on tobacco products that generate inhalable smoke or aerosol, such as cigarettes, cigars, hookah, electronic cigarettes, and heated tobacco products. We discuss challenges associated with sample generation including variability of smoking/vaping machines, lack of standardized adaptors that connect smoking/vaping machines to different tobacco products, puffing protocols that are not representative of actual use, and sample generation session length (minutes or number of puffs) that depends on product characteristics. We also discuss the challenges of physically …

Dynamic Fibrillar Assembly Of Αb-Crystallin Induced By Perturbation Of The Conserved Nt-Ixi Motif Resolved By Cryo-Em, Russell Mcfarland, Steve Reichow

Chemistry Faculty Publications and Presentations

αB-crystallin is an archetypical member of the small heat-shock proteins (sHSPs) vital for cellular proteostasis and mitigating protein misfolding diseases. Gaining insights into the principles defining their molecular organization and chaperone function have been hindered by intrinsic dynamic properties and limited high-resolution structural analysis. To disentangle the mechanistic underpinnings of these dynamical properties, we mutated a conserved IXI-motif located within the N-terminal (NT) domain of human αB-crystallin. This resulted in a profound structural transformation, from highly polydispersed caged-like native assemblies into a comparatively well-ordered helical fibril state amenable to high-resolution cryo-EM analysis. The reversible nature of the induced fibrils facilitated …