Other Chemistry Commons^™

The History And Development Of Identification: Rediscovery And Application Of Egyptian Blue, Bailee Allen

Chemistry & Biochemistry Student Projects

The use of fingerprints as a form of identification in criminal cases has become a common method of conviction within the criminal justice system. However, with the recent rise in the number of people wrongly convicted, the typical sources of evidence have come into question about their reliability. Multiple common drawbacks found when using fingerprints dusting to obtain prints from crime scenes has led to researchers looking for more efficient ways to collect them that maintain high sensitivity and contrast. These are the two aspects that create the largest problem, especially on highly reflective and highly patterned surfaces. The discovery …

The Chemistry Of Jellybeans, Andrew Carter

Chemistry & Biochemistry Student Projects

Jellybeans are an amazing work of chemistry. In my paper, I outline the history and science behind this little candy. My paper describes taste receptors, molecular structure, and the analytical chemistry that help to make flavor science an interesting field of work.

Metallodrugs And Their Various Impacts On Disorders And Diseases, Paige Wagner

Chemistry & Biochemistry Student Projects

No abstract provided.

Understanding Interactions Of Citropin 1.1 Analogues With Model Membranes And Their Influence On Biological Activity, Nathalia Rodrigues De Almeida, Jonathan Catazaro, Maddeboina Krishnaiah, Yashpal Singh Chhonker, Daryl J. Murry, Robert Powers, Martin Conda-Sheridan

Department of Chemistry: Faculty Publications

The rapid emergence of resistant bacterial strains has made the search for new antibacterial agents an endeavor of paramount importance. Cationic antimicrobial peptides (AMPs) have the ability to kill resistant pathogens while diminishing the development of resistance. Citropin 1.1 (Cit 1.1) is an AMP effective against a broad range of pathogens. 20 analogues of Cit 1.1 were prepared to understand how sequence variations lead to changes in structure and biological activity. Various analogues exhibited an increased antimicrobial activity relative to Cit 1.1. The two most promising, AMP-016 (W3F) and AMP-017 (W3F, D4R, K7R) presented a 2- to 8-fold increase in …

A Panel Of Protein Kinase Chemosensors Distinguishes Different Types Of Fatty Liver Disease, Jon R. Beck, Fatima Cabral, Karuna Rasineni, Carol A. Casey, Edward N. Harris, Cliff I. Stains

Department of Chemistry: Faculty Publications

The worldwide incidence of fatty liver disease continues to rise, which may account for concurrent increases in the frequencies of more aggressive liver ailments. Given the existence of histologically identical fatty liver disease subtypes, there is a critical need for the identification of methods that can classify disease and potentially predict progression. Herein, we show that a panel of protein kinase chemosensors can distinguish fatty liver disease subtypes. These direct activity measurements highlight distinct differences between histologically identical fatty liver diseases arising from diets rich in fat versus alcohol and identify a previously unreported decrease in p38α activity associated with …

Systematic Optimization For Production Of The Anti-Mrsa Antibiotics Wap-8294a In An Engineered Strain Of Lysobacter Enzymogenes, Xusheng Chen, Shanren Li, Lingjun Yu, Amanda Miller, Liangcheng Du

Department of Chemistry: Faculty Publications

WAP-8294A is a group of cyclic lipodepsipeptides and considered as the first-in-class new chemical entity with potent activity against methicillin-resistant Staphylococcus aureus. One of the roadblocks in developing the WAP-8294A antibiotics is the very low yield in Lysobacter. Here, we carried out a systematic investigation of the nutritional and environmental conditions in an engineered L. enzymogenes strain for the optimal production of WAP-8294A. We developed an activity-based simple method for quick screening of various factors, which enabled us to optimize the culture conditions. With the method, we were able to improve the WAP-8294A yield by 10-fold in small-scale cultures and …

The Forensic Analysis Of Skin-Safe Stamp Pad Inks, Swetha Rajagopal

Student Theses

Skin-safe stamp pad inks are currently being used at locations such as clubs, zoos and other events with the purpose of stamping individuals that visit the location. This is done in an attempt to monitor the number and activity of visitors. Ink manufacturing companies generally tend to experiment with a number of different combinations of the different components of ink, in order to obtain desirable properties. The combinations are usually proprietary and that very nature of the inks ends up making them, possibly unique and individual. The analysis, identification and possible individualization of the chemical composition of these inks could …

The Effects Of Ph On The Kinetics Of The Follow-Up Reaction Of Dopamine O-Quinone, Cyril Fong, Ziming Dong

Creative Activity and Research Day - CARD

The electrochemical studies of dopamine have been conducted for many years due to dopamine’s importance as a neurotransmitter and its function in daily life for individuals. Dopamine undergoes electrochemical redox reactions in which the different products can be detected by cyclic voltammetry.³ The focus of the experiments was to determine the pH range at which dopamine o-quinone would undergo cyclization as well as the relationship between the rate of cyclization as pH in the physiological range. The measurements were taken using a gold working electrode vs. a Ag/AgCl (1 M KCl) reference electrode. It was observed that the peaks …

Drug Improvement And Design Involving G-Protein Coupled Receptors, Gabriel Saliba

Chemistry & Biochemistry Student Projects

No abstract provided.

A Chemical Overview Of Opioid Receptors And Their Agonists, Noah Kuszak

Chemistry & Biochemistry Student Projects

This work is a brief overview of the three main opioid receptors and some current research of the ways we can change the agonists and how they affect the opioid receptor pathway.

Dentin Biomodification Potency Of Proanthocyanidins, David J. Ryker

Chemistry & Biochemistry Student Projects

No abstract provided.

Monitoring Transverse Relaxation Times Of Kerosene-Adulterated Diesel Using Low-Field Nuclear Magnetic Resonance Spectroscopy, Tristen Rumbaugh

Experiential Learning Projects

Time-domain nuclear magnetic resonance spectroscopy (TD-NMR) and low-field nuclear magnetic resonance spectroscopy (LF-NMR) are different techniques that vary in the range of magnetic field strengths that they use, which is a determining factor for the type of analysis that can be done. In this study, LF-NMR was used to perform a time-domain analysis of petroleum products, diesel and kerosene. This is a type of analysis which is typically performed using TD-NMR. Diesel and kerosene are two petroleum products that have different characteristics such as viscosity, boiling point, and hydrocarbon length. Diluting, or adulterating, diesel fuels with kerosene is a common …

Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar

Department of Chemistry: Faculty Publications

Understanding the degradation mechanisms of lead-halide perovskites (CH₃NH₃PbI₃) under exposure to liquid/aerosol water is an essential problem within the photovoltaic community. Herein we investigate both the static and the dynamic properties of the methylammonuim cation (MA) as it coordinates with invading water molecules (MA.(H₂O)_n, n = 1, 2, 3, 4) using both stationary state quantum mechanics and first principle molecular dynamics simulations. Various solvation structures of MA were characterized by their stabilization energies, dipoles, and Maximally-Localized Wannier Function (MLWF) centers. Calculation – and analysis – of vibrational shifts in the …

Structural Basis Of 7sk Rna 5′ Γ-Phosphate Methylation And Retention By Mepce, Yuan Yang, Catherine D. Eichhorn, Yaqiang Wang, Duilio Cascio, Juli Feigon

Department of Chemistry: Faculty Publications

Among RNA 5′-cap structures, γ-phosphate monomethylation is unique to a small subset of noncoding RNAs, 7SK and U6 in humans. 7SK is capped by methylphosphate capping enzyme (MePCE), which has a second non-enzymatic role as a core component of the 7SK RNP that is an essential regulator of RNA transcription. We report 2.0 and 2.1 Å X-ray crystal structures of human MePCE methyltransferase domain bound to S-adenosylhomocysteine (SAH) and uncapped or capped 7SK substrates, respectively. 7SK recognition is achieved by protein contacts to a 5′ hairpin-single-stranded RNA region, explaining MePCE specificity for 7SK and U6. The structures reveal SAH and …

Molecular Insights Into Cage Occupancy Of Hydrogen Hydrate: A Computational Study, Rui Ma, Hong Zhong, Jinxiang Liu, Jie Zhong, Youguo Yan, Jun Zhang, Jiafang Xu

Department of Chemistry: Faculty Publications

Density functional theory calculations and molecular dynamics simulations were performed to investigate the hydrogen storage capacity in the sII hydrate. Calculation results show that the optimum hydrogen storage capacity is ~5.6 wt%, with the double occupancy in the small cage and quintuple occupancy in the large cage. Molecular dynamics simulations indicate that these multiple occupied hydrogen hydrates can occur at mild conditions, and their stability will be further enhanced by increasing the pressure or decreasing the temperature. Our work highlights that the hydrate is a promising material for storing hydrogen.

Brush-Arm Star Polymer Imaging Agents And Uses Thereof, Jeremiah A. Johnson, Hung Vanthanh Nguyen, Andrzej Rajca

Department of Chemistry: Faculty Publications

Disclosed are methods, compositions, reagents, systems, and kits to prepare nitroxide-functionalized brush-arm star polymer organic radical contrast agent (BASP-ORCA) as well as compositions and uses thereof. Various embodiments show that BASP-ORCA display unprecedented per-nitrox-ide and per-molecule transverse relaxivities for organic radical contrast agents, exceptional stability, high water solubility, low in vitro and in vivo toxicity, and long blood compartment half-life. These materials have the potential to be adopted for tumor imaging using clinical high-field ¹H MRI techniques.

Growth Of Carbon Dioxide Whiskers, Avinash Kumar Both, Chin Li Cheung

Department of Chemistry: Faculty Publications

We report the growth of carbon dioxide (CO₂) whiskers at low temperatures (–70 °C to –65 °C) and moderate pressure (4.4 to 1.0 bar). Their axial growth was assessed by optical video analysis. The identities of these whiskers were confirmed as CO₂ solids by Raman spectroscopy. A vapor– solid growth mechanism was proposed based on the influence of the relative humidity on the growth.

Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar

Department of Chemistry: Faculty Publications

Understanding the degradation mechanisms of lead-halide perovskites (CH₃NH₃PbI₃) under exposure to liquid/aerosol water is an essential problem within the photovoltaic community. Herein we investigate both the static and the dynamic properties of the methylammonuim cation (MA) as it coordinates with invading water molecules (MA.(H₂O)_n, n = 1, 2, 3, 4) using both stationary state quantum mechanics and first principle molecular dynamics simulations. Various solvation structures of MA were characterized by their stabilization energies, dipoles, and Maximally-Localized Wannier Function (MLWF) centers. Calculation – and analysis – of vibrational shifts in the …

Indole Reverses Intrinsic Antibiotic Resistance By Activating A Novel Dual-Function Importer, Yan Wang, Tian Tian, Jingjing Zhang, Xin Jin, Huan Yue, Xiao-Hua Zhang, Liangcheng Du, Fan Bai

Department of Chemistry: Faculty Publications

Bacterial antibiotic resistance modulation by small signaling molecules is an emerging mechanism that has been increasingly reported in recent years. Several studies indicate that indole, an interkingdom signaling molecule, increases bacterial antibiotic resistance. However, the mechanism through which indole reduces antibiotic resistance is largely unknown. In this study, we demonstrated a novel mechanism for indole-mediated reversal of intrinsic antibiotic resistance in Lysobacter. This reversal was facilitated by a novel BtuD-associated dual-function importer that can transfer both vitamin B₁₂ and antibiotics. Indole stimulated btuD overexpression and promoted efficient absorption of extracellular vitamin B₁₂; meanwhile, the weak selectivity …

High Initial Reversible Capacity And Long Life Of Ternary Sno2‑Co‑Carbon Nanocomposite Anodes For Lithium‑Ion Batteries, Pan Deng, Jing Yang, Shengyang Li, Tian-E Fan, Hong-Hui Wu, Yun Mou, Hui Huang, Qiaobao Zhang, Dong-Liang Peng, Baihua Qu

Department of Chemistry: Faculty Publications

The two major limitations in the application of SnO₂ for lithium-ion battery (LIB) anodes are the large volume variations of SnO₂ during repeated lithiation/delithiation processes and a large irreversible capacity loss during the first cycle, which can lead to a rapid capacity fade and unsatisfactory initial Coulombic efficiency (ICE). To overcome these limitations, we developed composites of ultrafine SnO₂ nanoparticles and in situ formed Co(CoSn) nanocrystals embedded in an N-doped carbon matrix using a Co-based metal–organic framework (ZIF-67). The formed Co additives and structural advantages of the carbon-confined SnO₂/ Co nanocomposite effectively inhibited Sn coarsening …

Spheroid-3d And Monolayer-2d Intestinal Electrochemical Biosensor For Toxicity/Viability Testing: Applications In Drug Screening, Food Safety, And Environmental Pollutant Analysis, Evangelia Flampouri, Shahzad Imar, Kieran O'Connell, Baljit Singh

Articles

The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable …

Highly Stable And Efficient All-Inorganic Lead-Free Perovskite Solar Cells With Native-Oxide Passivation, Min Chen, Ming-Gang Ju, Hector F. Garces, Alexander D. Carl, Luis K. Ono, Zafer Hawash, Yi Zhang, Tianyi Shen, Yabing Qi, Ronald L. Grimm, Domenico Pacifici, Xiao Cheng Zeng, Yuanyuan Zhou, Nitin P. Padture

Department of Chemistry: Faculty Publications

There has been an urgent need to eliminate toxic lead from the prevailing halide perovskite solar cells (PSCs), but the current lead-free PSCs are still plagued with the critical issues of low efficiency and poor stability. This is primarily due to their inadequate photovoltaic properties and chemical stability. Herein we demonstrate the use of the lead-free, allinorganic cesium tin-germanium triiodide (CsSn_0.5Ge_0.5I₃) solid-solution perovskite as the light absorber in PSCs, delivering promising efficiency of up to 7.11%. More importantly, these PSCs show very high stability, with less than 10% decay in efficiency after 500 h …

Urease Is An Essential Component Of The Acid Response Network Of Staphylococcus Aureus And Is Required For A Persistent Murine Kidney Infection, Chunyi Zhou, Fatema Bhinderwala, Mckenzie K. Lehman, Vinai C. Thomas, Sujata S. Chaudhari, Kelsey J. Yamada, Kirk W. Foster, Robert Powers, Tammy Kielian, Paul D. Fey

Department of Chemistry: Faculty Publications

Staphylococcus aureus causes acute and chronic infections resulting in significant morbidity. Urease, an enzyme that generates NH₃ and CO₂ from urea, is key to pH homeostasis in bacterial pathogens under acidic stress and nitrogen limitation. However, the function of urease in S. aureus niche colonization and nitrogen metabolism has not been extensively studied. We discovered that urease is essential for pH homeostasis and viability in urea-rich environments under weak acid stress. The regulation of urease transcription by CcpA, Agr, and CodY was identified in this study, implying a complex network that controls urease expression in response to changes …

Machine Learning Enabled Prediction Of Mechanical Properties Of Tungsten Disulfide Monolayer, Xinyu Wang, Dan Han, Yang Hong, Haiyi Sun, Jingzhi Zhang, Jingchao Zhang

Department of Chemistry: Faculty Publications

One of two-dimensional transition metal dichalcogenide materials, tungsten disulfide (WS₂), has aroused much research interest, and its mechanical properties play an important role in a practical application. Here the mechanical properties of h-WS₂ and t-WS₂ monolayers in the armchair and zigzag directions are evaluated by utilizing the molecular dynamics (MD) simulations and machine learning (ML) technique. We mainly focus on the effects of chirality, system size, temperature, strain rate, and random vacancy defect on mechanical properties, including fracture strain, fracture strength, and Young’s modulus. We find that the mechanical properties of h-WS₂ surpass those of …

Insights Into Gemcitabine Resistance And The Potential For Therapeutic Monitoring, Teklab Gebregiworgis, Fatema Bhinderwala, Vinee Purohit, Nina V. Chaika, Pankaj K. Singh, Robert Powers

Department of Chemistry: Faculty Publications

Introduction—Gemcitabine is an important component of pancreatic cancer clinical management. Unfortunately, acquired gemcitabine resistance is widespread and there are limitations to predicting and monitoring therapeutic outcomes.

Objective—To investigate the potential of metabolomics to differentiate pancreatic cancer cells that develops resistance or respond to gemcitabine treatment.

Results—We applied 1D ¹H and 2D ¹H-¹³C HSQC NMR methods to profile the metabolic signature of pancreatic cancer cells. ¹³C₆-glucose labeling identified thirty key metabolites uniquely altered between wild-type and gemcitabine-resistant cells upon gemcitabine treatment. Gemcitabine resistance was observed to reprogram glucose metabolism and to enhance the pyrimidine …

Detailed Characterization Of The Solution Kinetics And Thermodynamics Of Biotin, Biocytin And Haba Binding To Avidin And Streptavidin, Roberto F. Delgadillo, Timothy C. Mueser, Kathia Zaleta-Rivera, Katie A. Carnes, Jose Gonzalez-Valdez, Lawrence J. Parkhurst

Department of Chemistry: Faculty Publications

The high affinity (K_D ~ 10⁻¹⁵ M) of biotin for avidin and streptavidin is the essential component in a multitude of bioassays with many experiments using biotin modifications to invoke coupling. Equilibration times suggested for these assays assume that the association rate constant (kon) is approximately diffusion limited (10⁹ M^-1s^-1) but recent single molecule and surface binding studies indicate that they are slower than expected (10⁵ to 10⁷ M^-1s^-1). In this study, we asked whether these reactions in solution are diffusion controlled, which reaction model and thermodynamic …

Chemical Kinetics Using A Smartphone Spectrometer, Mary Greggila

Williams Honors College, Honors Research Projects

In a time where many high school science classes are lacking in quality laboratory education, there is a need for accessible chemical equipment that enhance teaching fundamental concepts of chemistry with ease and at a low cost. The DualSpec handheld smartphone spectrometer aims to be a quality open-source spectroscopic instrument that can easily be made and used at home by people of any scientific level. This research sought to show that the DualSpec could be used to teach higher level spectroscopic concepts such as those used in chemical kinetics. The DualSpec was compared to a commercial spectrometer using the commonly …

Near-Infrared Fluorescent Probes For Sensitive Determination Of Lysosomal & Mitochondrial Ph In Live Cells, Wafa Mazi

Dissertations, Master's Theses and Master's Reports

Varied intracellular pH levels are critical for various physiological processes such as enzymatic activity, cell proliferation and apoptosis, ion transport, and muscle contraction. Cellular compartments, like lysosomes, must retain an acidic environment (pH ~ 4.5) to activate hydrolytic enzymes necessary for the breakdown of large biomolecules. Another cellular organelle, the mitochondria, provides the cell with energy and must retain an alkalis environment (pH ~ 8.0) for proper function. Substantial lysosomal and mitochondrial pH deviation is associated with cellular dysfunction and disease. Therefore, the precise detection of lysosomal and mitochondrial pH is essential to provide a better understanding of cellular physiological …

The Inductive Effect In Organic Chemistry, Charles A. Kingsbury

Department of Chemistry: Faculty Publications

The subtle difference between the successive polarization model and the flow of electrons through sigma bonds is explored, as well as the alternating charge model of Pople and the pervasive field model. The present paper is concerned with the ability of alkyl groups to serve as sigma inductive electron donors.

Electrocaloric Effect In Ferroelectric Ceramics With Point Defects, Ming Wu, Qingshan Zhu, Jianting Li, Dongsheng Song, Honghui Wu, Mengyao Guo, Jinghui Gao, Yang Bai, Yujun Feng, Stephen J. Pennycoock, Xiaojie Lou

Department of Chemistry: Faculty Publications

The electrocaloric effect has drawn much attention due to its potential application in cooling devices. A negative electrocaloric effect is predicted to be induced in defect-doped ferroelectrics by computational results [A. Grunebohm and T. Nishimatsu, Phys. Rev. B 93, 134101 (2016) and Ma et al., Phys. Rev. B 94, 094113 (2016)], but it need to be confirmed by experimental results. In this work, we prepared a 1mol. % Mn-doped Pb(Zr_0.2,Ti_0.8)O₃ ceramics (Pb((Zr_0.2,Ti_0.8)_0.99,Mn_0.01)O₃), and the electrocaloric effect of the defect-containing ferroelectric ceramics has …