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Full-Text Articles in Chemistry

The Reveal: A Technical Study And Conservation Treatment Of An Overpaint Portrait, Camille Ferrer Sep 2024

The Reveal: A Technical Study And Conservation Treatment Of An Overpaint Portrait, Camille Ferrer

Art Conservation Master's Projects

A severely damaged 19th-century oil painting depicting a portrait of a woman was treated at Patricia H. and E. Garman Art Conservation Department. A typed letter provided by the owner mentioned that it has been previously restored yet returned with unsatisfactory results. After further examination, the painting appeared to have been previously treated multiple times by different people. There was overpaint distinctly present on the face and later discovered to be present overall. The full state of condition of the painting was initially unknown due to the sum of the surface being overpainted. However, there were evidence of paint loss …


Highly Toxic Aβ Begets More Aβ, Merc M. Kemeh, Noel Lazo Sep 2024

Highly Toxic Aβ Begets More Aβ, Merc M. Kemeh, Noel Lazo

Chemistry

No abstract provided.


Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg Jul 2024

Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg

Chemistry Publications

Cassava is the third most significant calorie source in the tropics. Its processing has changed from traditional methods to stainless steel processing machines. This study investigated the influence of cassava on metal release from two common stainless steels, ASTM 304 and 201, with and without friction, and on tribocorrosion (multianalytically) of 304. Cassava was relatively corrosive and hindered repassivation of the surface oxide of stainless steel, but it also acted as a lubricant against mechanical friction. The combined action of friction and cassava caused a significant increase in iron, chromium, nickel, and manganese release from the stainless steels (30–35- fold …


Spectroscopic Characterization, Dft Calculations, In Vitro Pharmacological Potentials, And Molecular Docking Studies Of N, N, O-Schiff Base And Its Trivalent Metal Complexes, Ikechukwu P. Ejidike, Amani Direm, Cemal Parlak, Adebayo A. Adeniyi, Mohammad Azam, Athar Ata, Michael O. Eze, Joshua W. Hollett, Hadley S. Clayton Jun 2024

Spectroscopic Characterization, Dft Calculations, In Vitro Pharmacological Potentials, And Molecular Docking Studies Of N, N, O-Schiff Base And Its Trivalent Metal Complexes, Ikechukwu P. Ejidike, Amani Direm, Cemal Parlak, Adebayo A. Adeniyi, Mohammad Azam, Athar Ata, Michael O. Eze, Joshua W. Hollett, Hadley S. Clayton

Michigan Tech Publications, Part 2

In this study, trivalent metal complexes of the category: [M(L)(H2O)nCly] obtained from the interaction of metal3+ ion salts with organic N, N, O-Schiff base (HL) (where: HL = 4-{(Z)-((2-{(E)-((2-hydroxyphenyl)methylidene)amino}ethyl)imino)methyl}-2-methoxyphenol; n, y = 1 or 2 and M = Ti(III), Fe(III), Ru(III), Cr(III) and Al(III)) were synthesized and characterized viz molar conductance, FT-IR, and UV–Vis spectroscopies, elemental analyses, thermal analyses (TGA and DTA), and UV–Vis spectroscopy, theoretical calculations. A distorted octahedral structure around the metal ions was proposed based on the obtained experimental and calculated data. Thermal examination of the complexes signposts the step-by-step disintegration to give the final decomposition product …


Purification And Isolation Of Α-Chloro-Β-Lactone Precursor Molecules, Matthew Ellis May 2024

Purification And Isolation Of Α-Chloro-Β-Lactone Precursor Molecules, Matthew Ellis

Honors Projects

This research investigates the synthesis of α-chloro-β-lactone molecules, focusing on the production, isolation, and purification of two precursor compounds from chloroacetic acid and substituted benzaldehydes. While multiple methods were explored, including EDC, DIC, and DCC catalysis, DCC proved to be most effective in producing higher yields. However, challenges in purification arose due to the formation of byproducts, particularly with DCC, prompting further investigation for efficient extraction and purification techniques. DCC, however, shows a promising route for α-chloro-β-lactone synthesis, despite purification complexities.


Development Of An Enhanced Sampling Workflow To Accelerate Molecular Docking With Sparse Biophysical Information, Zachary Stichter May 2024

Development Of An Enhanced Sampling Workflow To Accelerate Molecular Docking With Sparse Biophysical Information, Zachary Stichter

Masters Theses & Specialist Projects

Rapid docking of flexible biological macromolecules remains a significant open challenge in protein structure determination. While rigid docking is relatively simple with toolkits such as TagDock, a key obstacle to rapid flexible docking is the complexity and roughness of the free energy surface associated with protein conformational motion (often termed the many-minima problem), meaning conventional molecular dynamics methods do not effectively sample protein conformations near the interaction complex in accessible timescales. Methods such as metadynamics and replica exchange molecular dynamics exist to ameliorate this obstacle, yet these methods use nonphysical biases or random swaps to enhance sampling. In contrast, high …


Modern Approaches To Treating Hospital Acquired Infections: An Overview Of Current Treatments Using Antibiotics And New Therapies Centered Around Photo-Activated Porphyrins, Meghan Johns Apr 2024

Modern Approaches To Treating Hospital Acquired Infections: An Overview Of Current Treatments Using Antibiotics And New Therapies Centered Around Photo-Activated Porphyrins, Meghan Johns

Senior Honors Theses

Annually, hospital-acquired infections (HAIs) affect hundreds of thousands of people in the U.S. and impose a great economic burden. The current problem is further exacerbated due to the failure of traditional treatment strategies considering the rise in antimicrobial resistance rates. Besides the fact that antimicrobial resistances complicates clinical treatment strategies, patients are also more vulnerable to secondary infections and complications from prolonged antibiotic use. As a result, research investigating novel treatment strategies for bacterial infections has recently increased. A strategy using porphyrin-based compounds is showing promise. Porphyrins and their derivatives have exhibited bactericidal effects against Gram-positive bacteria by the destruction …


Apigenin Alleviates Autistic-Like Stereotyped Repetitive Behaviors And Mitigates Brain Oxidative Stress In Mice, Petrilla Jayaprakash, Dmytro Isaev, Keun-Hang Susan Yang, Rami Beiram, Murat Oz, Bassem Sadek Apr 2024

Apigenin Alleviates Autistic-Like Stereotyped Repetitive Behaviors And Mitigates Brain Oxidative Stress In Mice, Petrilla Jayaprakash, Dmytro Isaev, Keun-Hang Susan Yang, Rami Beiram, Murat Oz, Bassem Sadek

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Studying the involvement of nicotinic acetylcholine receptors (nAChRs), specifically α7-nAChRs, in neuropsychiatric brain disorders such as autism spectrum disorder (ASD) has gained a growing interest. The flavonoid apigenin (APG) has been confirmed in its pharmacological action as a positive allosteric modulator of α7-nAChRs. However, there is no research describing the pharmacological potential of APG in ASD. The aim of this study was to evaluate the effects of the subchronic systemic treatment of APG (10–30 mg/kg) on ASD-like repetitive and compulsive-like behaviors and oxidative stress status in the hippocampus and cerebellum in BTBR mice, utilizing the reference drug aripiprazole (ARP, 1 …


Advanced Electroanalysis For Electrosynthesis, Monica Brachi, Wassim El Housseini, Kevin Beaver, Rohit Jadhav, Ashwini Dantanarayana, Dylan G. Boucher, Shelley D. Minteer Apr 2024

Advanced Electroanalysis For Electrosynthesis, Monica Brachi, Wassim El Housseini, Kevin Beaver, Rohit Jadhav, Ashwini Dantanarayana, Dylan G. Boucher, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Electrosynthesis is a Popular, Environmentally Friendly Substitute for Conventional Organic Methods. It Involves using Charge Transfer to Stimulate Chemical Reactions through the Application of a Potential or Current between Two Electrodes. in Addition to Electrode Materials and the Type of Reactor Employed, the Strategies for Controlling Potential and Current Have an Impact on the Yields, Product Distribution, and Reaction Mechanism. in This Review, Recent Advances Related to Electroanalysis Applied in Electrosynthesis Were Discussed. the First Part of This Study Acts as a Guide that Emphasizes the Foundations of Electrosynthesis. These Essentials Include Instrumentation, Electrode Selection, Cell Design, and Electrosynthesis Methodologies. …


Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang Apr 2024

Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang

Chemistry Faculty Research & Creative Works

In the Field of Chiral Recognition, Chiral Cyclic Organic Compounds, Especially Heterocyclic Organic Compounds, Have Attracted Little Attention and Have Been Rarely Studied as Chiral Substrates by Means of 1H NMR Spectroscopy. in This Paper, Enantiomers of Thiohydantoin Derivatives, Representing Typical Five-Membered N,N-Heterocycles, Have Been Synthesized and Utilized for Assignment of Absolute Configuration and Analysis of Enantiomeric Excess. All Enantiomers Have Been Successfully Differentiated with the Assistance of Novel Tetraaza Macrocyclic Chiral Solvating Agents (TAMCSAs) by 1H NMR Spectroscopy. Surprisingly, Unprecedented Nonequivalent Chemical Shift Values (Up to 2.052 Ppm) of the NH Proton of Substrates Have Been Observed, a New …


Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal Apr 2024

Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The malting process takes one week to steep, germinate, and kiln barley to make malt. Making quality malt is critically important to achieve the desired attributes of the finished beer, and the process is time-intensive and costly. Malt quality is assessed by indicators including β-glucan quantity, α-amylase activity, Free Amino Nitrogen (FAN) content, and overall extract concentration in the finished malt. Here, we report Pulsed Electric Field (PEF) treatment of barley to accelerate malt production. A small-scale trial of 250 g to 1.00 kg barley, was evaluated for germination at two PEF treatment conditions, generically referred to as “low” and …


Accurate Characterization Of Binding Kinetics And Allosteric Mechanisms For The Hsp90 Chaperone Inhibitors Using Ai-Augmented Integrative Biophysical Studies, Chao Xu, Xianglei Zhang, Lianghao Zhao, Gennady M. Verkhivker, Fang Bai Apr 2024

Accurate Characterization Of Binding Kinetics And Allosteric Mechanisms For The Hsp90 Chaperone Inhibitors Using Ai-Augmented Integrative Biophysical Studies, Chao Xu, Xianglei Zhang, Lianghao Zhao, Gennady M. Verkhivker, Fang Bai

Mathematics, Physics, and Computer Science Faculty Articles and Research

The binding kinetics of drugs to their targets are gradually being recognized as a crucial indicator of the efficacy of drugs in vivo, leading to the development of various computational methods for predicting the binding kinetics in recent years. However, compared with the prediction of binding affinity, the underlying structure and dynamic determinants of binding kinetics are more complicated. Efficient and accurate methods for predicting binding kinetics are still lacking. In this study, quantitative structure–kinetics relationship (QSKR) models were developed using 132 inhibitors targeting the ATP binding domain of heat shock protein 90α (HSP90α) to predict the dissociation rate …


Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne Frances Miller Apr 2024

Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne Frances Miller

Chemistry Faculty Research & Creative Works

The Flavodoxin Of Rhodopseudomonas Palustris CGA009 (Rp9Fld) Supplies Highly Reducing Equivalents To Crucial Enzymes Such As Hydrogenase, Especially When The Organism Is Iron-Restricted. By Acquiring Those Electrons From Photodriven Electron Flow Via The Bifurcating Electron Transfer Flavoprotein, Rp9Fld Provides Solar Power To Vital Metabolic Processes. To Understand Rp9Fld's Ability To Work With Diverse Partners, We Solved Its Crystal Structure. We Observed The Canonical Flavodoxin (Fld) Fold And Features Common To Other Long-Chain Flds But Not All The Surface Loops Thought To Recognize Partner Proteins. Moreover, Some Of The Loops Display Alternative Structures And Dynamics. To Advance Studies Of Protein–protein Associations …


Nitrene-Transfer Chemistry To C-H And C═C Bonds Mediated By Triangular Coinage Metal Platforms Supported By Triply Bridging Pnictogen Elements Sb(Iii) And Bi(Iii), Meenakshi Sharma, Reece M. Fritz, Joseph O. Adebanjo, Zhou Lu, Thomas R. Cundari, Mohammad A. Omary, Amitava Choudhury, Pericles Stavropoulos Mar 2024

Nitrene-Transfer Chemistry To C-H And C═C Bonds Mediated By Triangular Coinage Metal Platforms Supported By Triply Bridging Pnictogen Elements Sb(Iii) And Bi(Iii), Meenakshi Sharma, Reece M. Fritz, Joseph O. Adebanjo, Zhou Lu, Thomas R. Cundari, Mohammad A. Omary, Amitava Choudhury, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

Tripodal Ligands (TMG3trphen-E) That Feature Heavy Pnictogen Elements (E = Sb(III), Bi(III)) And Tetramethylguanidinyl (TMG) Arms Have Been Explored In Stabilizing Cu(I) And Ag(I) Sites And Facilitating Nitrene-Transfer Chemistry. Compounds [(TMG3trphen-E)M3(Μ-X)3] (M = Cu(I), Ag(I); X = Cl, Br, I) Have Been Generated Upon Extraction Of M3(Μ-X)3 Units From MX Sources, Exhibiting Support Of The Crown-Shaped M3(Μ-X)3 Fragment By M-NTMG Bonds And Triply Bridging E → M3 Interactions. Orbital Interactions Between Cu(I) Sites And NTMG Residues Are More Dominant Than Sb/Bi → Cu3 Donor Interactions Between The Sb 5s Or Bi 6s Orbitals And Admixed Cu 4s/3d Orbitals, With Larger …


Embedding Information Literacy Practices In An Upper Division Chemistry Lab Class At A University In The United States Of America, Christopher Randles, Matilynn Lamm, Katy A. Miller Mar 2024

Embedding Information Literacy Practices In An Upper Division Chemistry Lab Class At A University In The United States Of America, Christopher Randles, Matilynn Lamm, Katy A. Miller

Faculty Scholarship and Creative Works

This poster discusses the implementation of information literacy into an upper division inorganic chemistry lab and the strategies employed to develop students’ information literacy in the laboratory course.


Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben Oumnov, Orhan Kizilkaya, Randall W. Hall, Philip T. Sprunger, Robert L. Cook Mar 2024

Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben Oumnov, Orhan Kizilkaya, Randall W. Hall, Philip T. Sprunger, Robert L. Cook

Natural Sciences and Mathematics | Faculty Scholarship

Environmentally persistent free radicals (EPFRs), a group of emerging pollutants, have significantly longer lifetimes than typical free radicals. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface involving electron charge transfer between the organic and TMO. In this paper, dihalogenated benzenes were incorporated to study the role of electronegativity in the electron transfer process to obtain a fundamental knowledge of EPFR formation mechanism on ZnO. Upon chemisorption on ZnO nanoparticles at 250 °C, electron paramagnetic resonance (EPR) confirms the formation of oxygen adjacent carbon-centered organic free radicals with concentrations between 1016 and 1017 spins/g. …


Β-Sheets Mediate The Conformational Change And Allosteric Signal Transmission Between The Aslov2 Termini, Sian Xiao, Mayar Terek Ibrahim, Gennady M. Verkhivker, Brian D. Zoltowski, Peng Tao Mar 2024

Β-Sheets Mediate The Conformational Change And Allosteric Signal Transmission Between The Aslov2 Termini, Sian Xiao, Mayar Terek Ibrahim, Gennady M. Verkhivker, Brian D. Zoltowski, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

Avena sativa phototropin 1 light-oxygen-voltage 2 domain (AsLOV2) is a model protein of Per-Arnt-Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change begins with the unfolding of the N-terminal A'α helix in the dark state followed by the unfolding of the C-terminal Jα helix. The light state is characterized by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β-sheets are identified as crucial components for mediating allosteric signal transmission between the two termini. Through combined experimental and computational investigations, the Hβ …


Novel Inhibitors To Mmpl3 Transporter Of Mycobacterium Tuberculosis By Structure-Based High-Throughput Virtual Screening And Molecular Dynamics Simulations, Hetanshi Choksi, Justin Carbone, Nicholas J. Paradis, Lucas Bennett, Candice Bui-Linh, Chun Wu Mar 2024

Novel Inhibitors To Mmpl3 Transporter Of Mycobacterium Tuberculosis By Structure-Based High-Throughput Virtual Screening And Molecular Dynamics Simulations, Hetanshi Choksi, Justin Carbone, Nicholas J. Paradis, Lucas Bennett, Candice Bui-Linh, Chun Wu

Faculty Scholarship for the College of Science & Mathematics

Tuberculosis (TB)-causing bacterium Mycobacterium tuberculosis (Mtb) utilizes mycolic acids for building the mycobacterial cell wall, which is critical in providing defense against external factors and resisting antibiotic action. MmpL3 is a secondary resistance nodulation division transporter that facilitates the coupled transport of mycolic acid precursor into the periplasm using the proton motive force, thus making it an attractive drug target for TB infection. In 2019, X-ray crystal structures of MmpL3 from M. smegmatis were solved with a promising inhibitor SQ109, which showed promise against drug-resistant TB in Phase II clinical trials. Still, there is a pressing need to discover more …


Highly Efficient Dopamine Sensing With A Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure, Harish Singh, Jiandong Wu, Kurt A.L. Lagemann, Manashi Nath Mar 2024

Highly Efficient Dopamine Sensing With A Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure, Harish Singh, Jiandong Wu, Kurt A.L. Lagemann, Manashi Nath

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon nanotube-encapsulated nickel selenide composite nanostructures were used as nonenzymatic electrochemical sensors for dopamine detection. These composite nanostructures were synthesized through a simple, one-step, and environmentally friendly chemical vapor deposition method, wherein the CNTs were formed in situ from pyrolysis of a carbon-rich metallo-organic precursor. The composition and morphology of these hybrid NiSe2-filled carbon nanostructures were confirmed by powder X-ray diffraction, Raman, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy images. Electrochemical tests demonstrated that the as-synthesized hybrid nanostructures exhibited outstanding electrocatalytic performance toward dopamine oxidation, with a high sensitivity of 19.62 μA μM-1 cm-2, low detection limit, broad linear …


Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan Mar 2024

Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan

Michigan Tech Publications, Part 2

Neuroinflammation and brain oxidative stress are recognized as significant contributors to hypertension including salt sensitive hypertension. Extracellular vesicles (EVs) play an essential role in intercellular communication in various situations, including physiological and pathological ones. Based on this evidence, we hypothesized that EVs derived from the brains of hypertensive rats with salt sensitivity could trigger neuroinflammation and oxidative stress during hypertension development. To test this hypothesis, we compared the impact of EVs isolated from the brains of hypertensive Dahl Salt-Sensitive rats (DSS) and normotensive Sprague Dawley (SD) rats on inflammatory factors and mitochondrial reactive oxygen species (mtROS) production in primary neuronal …


Analyzing Biomedical Datasets With Symbolic Tree Adaptive Resonance Theory, Sasha Petrenko, Daniel B. Hier, Mary A. Bone, Tayo Obafemi-Ajayi, Erik J. Timpson, William E. Marsh, Michael Speight, Donald C. Wunsch Mar 2024

Analyzing Biomedical Datasets With Symbolic Tree Adaptive Resonance Theory, Sasha Petrenko, Daniel B. Hier, Mary A. Bone, Tayo Obafemi-Ajayi, Erik J. Timpson, William E. Marsh, Michael Speight, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Biomedical Datasets Distill Many Mechanisms Of Human Diseases, Linking Diseases To Genes And Phenotypes (Signs And Symptoms Of Disease), Genetic Mutations To Altered Protein Structures, And Altered Proteins To Changes In Molecular Functions And Biological Processes. It Is Desirable To Gain New Insights From These Data, Especially With Regard To The Uncovering Of Hierarchical Structures Relating Disease Variants. However, Analysis To This End Has Proven Difficult Due To The Complexity Of The Connections Between Multi-Categorical Symbolic Data. This Article Proposes Symbolic Tree Adaptive Resonance Theory (START), With Additional Supervised, Dual-Vigilance (DV-START), And Distributed Dual-Vigilance (DDV-START) Formulations, For The Clustering Of …


3d Pictorial Representations Of O2- And Ho2 Compared To Dft Results, Tzu-Hsiang Huang, Joseph D. Alia Mar 2024

3d Pictorial Representations Of O2- And Ho2 Compared To Dft Results, Tzu-Hsiang Huang, Joseph D. Alia

Chemistry Publications

The Linnett Double Quartet (LDQ) (1) and Bohr Orbit Bonding (BOB) (2) methods were used to accurately represent the spin density distribution for superoxide (O2 -) and hydroperoxyl radical (HO2). These structural pictures were superimposed on the spin density plot produced by DFT. The Valency Interaction Formula (VIF) method (3) was also applied to these molecules and it matched the NBOs from NBO analysis of DFT results. The interaction between O2 - and H2O were analyzed and the stronger basicity of the beta-spin electrons of superoxide was identified by looking at the LDQ structure and confirmed with NBO analysis. The …


Limonene Enantiomeric Ratios From Anthropogenic And Biogenic Emission Sources, Shan Gu, Wentai Luo, Avisa Charmchi, Kevin J. Mcwhirter, Todd Rosenstiel, James F. Pankow Mar 2024

Limonene Enantiomeric Ratios From Anthropogenic And Biogenic Emission Sources, Shan Gu, Wentai Luo, Avisa Charmchi, Kevin J. Mcwhirter, Todd Rosenstiel, James F. Pankow

Chemistry Faculty Publications and Presentations

Emissions from volatile chemical products (VCPs) have been identified as contributors to air quality degradation in urban areas. Limonene can be a tracer compound for VCPs containing fragrances in densely populated regions, but limonene is also emitted from conifers that are planted in urban areas. This creates challenges for using limonene to estimate VCP emissions. In this study, the −/+ enantiomeric ratios of limonene from VCP and conifer emission sources were quantified to evaluate if this measurement could be used to aid in source apportionment and emission inventory development. Samples were analyzed using a gas chromatograph equipped with a chiral …


Using Flipped Classroom Modules To Facilitate Higher Order Learning In Undergraduate Organic Chemistry, Lauren R. Holloway, Tabitha Miller, Bryce Da Camara, Paul M. Bogie, Briana L. Hickey, Jack Barbera, Angie L. Lopez, Multiple Additional Authors Mar 2024

Using Flipped Classroom Modules To Facilitate Higher Order Learning In Undergraduate Organic Chemistry, Lauren R. Holloway, Tabitha Miller, Bryce Da Camara, Paul M. Bogie, Briana L. Hickey, Jack Barbera, Angie L. Lopez, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

In an ongoing effort to incorporate active learning and promote higher order learning outcomes in undergraduate organic chemistry, a hybrid (“flipped”) classroom structure has been used to facilitate a series of collaborative activities in the first two courses of the lower division organic chemistry sequence. An observational study of seven classes over a five-year period reveals there is a strong correlation between performance on the in-class activities and performance on the final exam across all classes; however, a significant number of students in these courses continue to struggle on both the in-class activities and final exam. The Activity Engagement Survey …


Dna-Based Assay For Calorimetric Determination Of Protein Concentrations In Pure Or Mixed Solutions, Matthew W. Eskew, Patrick Reardon, Albert S. Benight Mar 2024

Dna-Based Assay For Calorimetric Determination Of Protein Concentrations In Pure Or Mixed Solutions, Matthew W. Eskew, Patrick Reardon, Albert S. Benight

Chemistry Faculty Publications and Presentations

It was recently reported that values of the transition heat capacities, as measured by differential scanning calorimetry, for two globular proteins and a short DNA hairpin in NaCl buffer are essentially equivalent, at equal concentrations (mg/mL). To validate the broad applicability of this phenomenon, additional evidence for this equivalence is presented that reveals it does not depend on DNA sequence, buffer salt, or transition temperature (Tm). Based on the equivalence of transition heat capacities, a calorimetric method was devised to determine protein concentrations in pure and complex solutions. The scheme uses direct comparisons between the thermodynamic stability of a short …


Two-Electron Density Of Three Electrons In A 1d Box: A Model System For Visualizing Spin Correlation Due To Antisymmetry Of Electrons, Joseph D. Alia Mar 2024

Two-Electron Density Of Three Electrons In A 1d Box: A Model System For Visualizing Spin Correlation Due To Antisymmetry Of Electrons, Joseph D. Alia

Chemistry Publications

Visual models for understanding electron density distribution in molecules are useful for chemical reasoning. The Lewis structure for example compares well to one-electron density when all electrons are paired. Linnett Double Quartet structures compare well to some kinds of free radical species. These approaches do not show the behavior of the total electron wavefunction when two electrons near each other. This behavior is a two- electron property and can be visualized with the model of three electrons in a one- dimensional box. The two-electron density of the three electron wavefunction described as a slater determinent of 1D particle-in-a-box spin- orbitals …


The Α-Crystallin Chaperones Undergo A Quasi-Ordered Co-Aggregation Process In Response To Saturating Client Interaction, Kirsten Lampi, Adam P. Miller, Susan E. O'Neill, Steve L. Reichow Mar 2024

The Α-Crystallin Chaperones Undergo A Quasi-Ordered Co-Aggregation Process In Response To Saturating Client Interaction, Kirsten Lampi, Adam P. Miller, Susan E. O'Neill, Steve L. Reichow

Chemistry Faculty Publications and Presentations

Small heat shock proteins (sHSPs) are ATP-independent chaperones vital to cellular proteostasis, preventing protein aggregation events linked to various human diseases including cataract. The α-crystallins, αA-crystallin (αAc) and αB-crystallin (αBc), represent archetypal sHSPs that exhibit complex polydispersed oligomeric assemblies and rapid subunit exchange dynamics. Yet, our understanding of how this plasticity contributes to chaperone function remains poorly understood. This study investigates structural changes in αAc and αBc during client sequestration under varying degree of chaperone saturation. Using biochemical and biophysical analyses combined with single-particle electron microscopy (EM), we examined αAc and αBc in their apo-states and at various stages of …


Raw Nmr Data For Tripeptides, David J. Michaelis, Scott R. Burt, Mariur Rodriguez Moreno, Nye C. Johnson, Christopher B. Stewart, Mary L. Setelin, Adam X. Wayment, Braxton M. Felix Feb 2024

Raw Nmr Data For Tripeptides, David J. Michaelis, Scott R. Burt, Mariur Rodriguez Moreno, Nye C. Johnson, Christopher B. Stewart, Mary L. Setelin, Adam X. Wayment, Braxton M. Felix

ScholarsArchive Data

This data set contains primary data for 50 tripeptides that were generated as part of an advanced undergraduate laboratory experience in solid phase peptide synthesis. The raw data can be processed sing NMR interpretation software and can be used as problems for exams and quizzes or as supplementary materials for a laboratory experience


Toward A Coordinated Understanding Of Hydro-Biogeochemical Root Functions In Tropical Forests For Application In Vegetation Models, Daniela F. Cusack, Bradley Christoffersen, Chris M. Smith-Martin, Kelly M. Andersen, Amanda L. Cordeiro, Katrin Fleischer, S. Joseph Wright, Nathaly R. Guerrero-Ramírez, Laynara F. Lugli, Lindsay A. Mcculloch, Mareli Sanchez-Julia, Sarah A. Batterman, Caroline Dallstream, Claire Fortunel, Laura Toro, Lucia Fuchslueger, Michelle Y. Wong, Daniela Yaffar, Joshua B. Fisher, Marie Arnaud, Lee H. Dietterich, Shalom D. Addo-Danso, Oscar J. Valverde-Barrantes, Monique Weemstra, Jing Cheng Ng, Richard J. Norby Feb 2024

Toward A Coordinated Understanding Of Hydro-Biogeochemical Root Functions In Tropical Forests For Application In Vegetation Models, Daniela F. Cusack, Bradley Christoffersen, Chris M. Smith-Martin, Kelly M. Andersen, Amanda L. Cordeiro, Katrin Fleischer, S. Joseph Wright, Nathaly R. Guerrero-Ramírez, Laynara F. Lugli, Lindsay A. Mcculloch, Mareli Sanchez-Julia, Sarah A. Batterman, Caroline Dallstream, Claire Fortunel, Laura Toro, Lucia Fuchslueger, Michelle Y. Wong, Daniela Yaffar, Joshua B. Fisher, Marie Arnaud, Lee H. Dietterich, Shalom D. Addo-Danso, Oscar J. Valverde-Barrantes, Monique Weemstra, Jing Cheng Ng, Richard J. Norby

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest–climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics …


Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim Feb 2024

Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim

Faculty Publications

River networks play a crucial role in the global carbon cycle, as relevant sources of carbon dioxide (CO2) to the atmosphere. Advancements in high-frequency monitoring in aquatic environments have enabled measurement of dissolved CO2 concentration at temporal resolutions essential for studying carbon variability and evasion from these dynamic ecosystems. Here, we describe the adaptation, deployment, and validation of an open-source and relatively low-cost in situ pCO2 sensor system for lotic ecosystems, the lotic-SIPCO2. We tested the lotic-SIPCO2 in 10 streams that spanned a range of land cover and basin size. Key system adaptations for lotic environments included prevention of biofouling, …