Chemistry Commons^™

Identification Of Rickettsia Prowazekii Methionine Aminopeptidase Inhibitors And Development Of Thermal Shift Assays For Burkholderia Pseudomallei Ispf And Sars-Cov-2 3cl Protease, Ishpriya Sharma

Graduate Research Theses & Dissertations

There is a crucial need for new antibacterial agents to combat the increase in antibiotic resistance. Methionine aminopeptidase (MetAp) is an enzyme that removes the amino-terminal methionine residue from newly synthesized proteins, an important step in the maturation of proteins. As such, MetAp is a target for the development of antibacterial and anticancer agents. One such bacterial target is Rickettsia prowazekii (Rp), the causative agent of epidemic typhus. To discover new inhibitors of RpMetAp1, the MMV Malaria Box, which is a collection of 400 compounds with drug-like and probe-like compounds, was screened using a high throughput fluorescence-based RpMetAp1 enzyme inhibition …

Homopurine Guanine-Rich Sequences In Complex With N-Methyl Mesoporphyrin Ix Form Parallel G-Quadruplex Dimers And Display A Unique Symmetry Tetrad, Ming Ye , '23, Erin V. Chen , '23, S. H. Pfeil, Kailey N. Martin, Tamanaa Atrafi , '23, Sara Yun , '23, Zahara Martinez , '23, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by π-π stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets. We identified a 42-nucleotide long, purine-only G-rich sequence from human genome, which contains eight G-stretches connected by A and AAAA loops. We divided this sequence into five unique segments, four guanine stretches each, named GA1-5. In order to investigate the role of adenines in GQ structure formation, we performed biophysical and X-ray crystallographic studies of GA1-5 and their complexes with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). Our data indicate …

Facile Electrochemical Preparation Of Hydrophobic Antibacterial Fabrics Using Reduced Graphene Oxide/Silver Nanoparticles, Behnaz Jafari, Carla M.R. Lacerda, Gerardine G. Botte

Jasper Department of Chemical Engineering Faculty Publications and Presentations

A novel facile electrochemical method was developed for in situ coating of fabrics with reduced graphene oxide/silver nanoparticles. The procedure consisted of three steps: spray coating of graphene oxide on the fabric, electrochemical reduction of the graphene oxide layer, and electrodeposition of silver nanoparticles on the fabrics. All the steps were performed at room temperature without using a toxic reducing agent. The fabrics coated with reduced graphene oxide/silver nanoparticles demonstrated excellent hydrophobicity (water contact angle of 148.0° 1.1) and strong antibacterial activity against gram negative Escherichia coli bacteria (reduction rate >99.99%). The durability of the modified fabrics was investigated by …

Vanadium Partitioning Between Magnetite, Hematite, And A Hydrothermal Fluid: Implications For Iocg And Ioa Deposits, Jeremy Raymond Nederbo

Graduate Research Theses & Dissertations

Iron oxide-copper-gold (IOCG) and iron oxide-apatite (IOA) deposits are major sources of iron contained within magnetite and/or hematite as well as copper contained within copper-iron sulfides and gold as a native metal. Their formations have been attributed to magmatic, hydrothermal, or a mixture of magmatic-hydrothermal processes. Vanadium can readily substitute into magnetite via ion exchange due to similar atomic radii and charges as iron and has thus been hypothesized to be an effective tracer of hydrothermal or magmatic inputs. To evaluate the mobility of vanadium in a magnetite-hematite-fluid system, experiments on the partitioning of vanadium between magnetite, hematite and a …

Lets Make Rock Candy!, Admin Stem For Success

STEM for Success Showcase

• Students should…

• be familiar with terms such as solubility, solute, solvent, and supersaturated solution.

• have a basic understanding of crystallization.

• understand the concept of delayed gratification and how they can practice this skill in their everyday lives to make smart financial decisions.

Hovering Potato ~ Activity Plan, Admin Stem For Success

STEM for Success Showcase

This experiment is a great example of chemistry. This experiment relies heavily on density and diffusion.

• Water is less dense than half of a potato. Therefore, the potato sinks.

• Sugar water is more dense than half of a potato. Therefore, the potato floats.

By slowly adding water to sugar water, two layers are formed which allows the potato to hover in between. Slowly adding the water allows for diffusion to occur at a minimum.

Slime Lesson Plans, Admin Stem For Success

STEM for Success Showcase

The STEM for success ambassador program will provide high school students the opportunity to participate in STEM activities that challenge them to learn topics covered in most high school chemistry and physics courses in an environment that cultivates leadership, STEM advocacy, and the 21st century skills of creativity and collaboration. High school students will learn tie-dye science and the chemistry and physics of slime and use their learning experiences to create hands-on activities for Pre-K through 8th grade students. High school students will form teams and venture out into their communities to explore the activities they have created in local …

Design, Evolution, And Evaluation Of A General Chemistry-Bridging Course, Scott A. Reid

Chemistry Faculty Research and Publications

General chemistry I/II courses are important gateway courses for a variety of STEM majors, as poor performance in these courses is often associated with lower rates of student success and retention. Much research has explored preparatory or remedial strategies to improve student outcomes. In this article, we report a different approach, which involved the development of a bridging or intervention course designed to capture students who are not or have not succeeded in general chemistry I and prepare them to retake the course in the following semester or summer. The course was initially developed as an eight-week module in the …

Split Catalytic Probes For The Detection Of Monkeypox Virus, Jaehyun Ahn

Honors Undergraduate Theses

The COVID-19 outbreak highlighted the important role that diagnostic tests play in the healthcare system. To reduce the impact of infectious disease outbreaks, the development of rapid and cost-effective point-of-care-tests (POCTs) is crucial. With the dissemination of the Monkeypox (Mpox) virus, it became a necessity to produce POCTS that are inexpensive and easy to use. This work explored the construction of two colorimetric assays that aim to detect Mpox genetic signatures. One is based on the split-peroxidase-like deoxyribozyme probes (sPDz), while the other utilizes a cascade system of split RNA-cleaving deoxyribozyme (sDz) and peroxidase-like deoxyribozyme (PDz). Both rely on catalytic …

Analysis Of Polycyclic Aromatic Hydrocarbons In Tobacco Related Samples Via High Performance Liquid Chromatography And Laser Excited Time Resolved Shpol' Skii Spectroscopy, Ahmed Comas

Electronic Theses and Dissertations, 2020-2023

Human exposure to polycyclic aromatic hydrocarbons (PAHs) due to cigarette smoke is well known. It is also known that PAHs are not inherent components of tobacco. Their presence in cigarette smoke results from the curing process of tobacco leaves used for the fabrication of cigarettes and the incomplete combustion of tobacco during the smoking process. The two chromatographic versions of EPA method 610 are popular approaches for the analysis of PAHs in a wide variety of samples. This method, which is based either on High-Performance Liquid-Chromatography (HPLC) or Gas-Chromatography (GC) has shown the presence of Benzo[a]pyrene (B[a]P) in tobacco samples …

Mechanism Of Pth Ca2+ Sensing On G-Protein Interactions With Pth1r, Difei Jiang

Lawrence University Honors Projects

Parathyroid hormone 1 receptor (PTH1R) is a family-B GPCR that plays a crucial role in bone remodeling. Previous studies show extracellular Ca2+ is a positive allosteric modulator for one PTH1R ligand, parathyroid hormone (PTH), which is approved by US FDA to treat severe osteoporosis. Moreover, PTH residues E19 & E22 have shown to be involved in Ca2+ sensing. However, the effects of PTH Ca2+ sensing on intracellular G-protein binding are unknown. Here, we used FRET-based SPASM sensors to study the interaction between PTH1R and different Ga peptides. SPASM sensors, which are isolated in native HEK293T membranes through optimized protocol, contain …

Electrodeposition Of Epitaxial Wide Bandgap P-Type Semiconductors And Copper Metal For Energy Conversion And Flexible Electronics, Bin Luo

Doctoral Dissertations

"Epitaxial electrodeposition is a simple, low-cost technology to produce highly ordered materials on single-crystal surfaces. This research focuses on the epitaxial electrodeposition of wide bandgap p-type semiconductors and epitaxial Cu thin films via a self-assembled monolayer for energy conversion and flexible electronics. Paper I introduces the epitaxial electrodeposition of hole conducting CuSCN nanorods onto Au (111) surface, and lift-off to produce flexible and transparent foils. Highly ordered CuSCN could serve as an inorganic transport layer in various opto-electronic devices such as perovskite solar cells, LEDs, and transistors. An ordered and transparent CuSCN foil was also produced by epitaxial lift-off following …

Flipping The Thinking On Equality, Diversity, And Inclusion. Why Edi Is Essential For The Development And Progression Of The Chemical Sciences: A Case Study Approach, M. Anwar H. Khan, Timothy G. Harrison, Magdalena Wajrak, Michele Grimshaw, Kathy G. Schofield, Alison J. Trew, Kulvinder Johal, Jeannette Morgan, Karen L. Shallcross, Joyce D. Sewry, Michael T. Davies-Coleman, Dudley E. Shallcross

Research outputs 2022 to 2026

All learners have a contribution to make to the development of the Chemical Sciences, be that in novel ways to teach, and their perspectives and contexts, but also in research, both in chemical education and the wider Chemical Sciences. Through four case studies, this paper explores interactions with diverse groups and how this has altered perspectives on both teaching and research. The case studies include work with visually impaired adults, a project bringing together First Peoples in Australia with academics to explore old ways (traditional science) and new ways (modern approaches), primary (elementary) school perspectives on teaching science, and a …

Comparative Static And Dynamic Analyses Of Solvents For Removal Of Asphaltene And Wax Deposits Above- And Below-Surface At An Iranian Carbonate Oil Field, Milad Norouzpour, Amin Azdarpour, Rafael M. Santos, Ali Esfandiarian, Moein Nabipour, Erfan Mohammadian, Abbas K. Manshad, Alireza Keshavarz

Research outputs 2022 to 2026

During production from oil wells, the deposition of asphaltene and wax at surface facilities and porous media is one of the major operational challenges. The crude oil production rate is significantly reduced due to asphaltene deposition inside the reservoir. In addition, the deposition of these solids inside the surface facilities is costly to oil companies. In this study, the efficiency of different solvents in dissolving asphaltene and wax was investigated through static and dynamic tests. The analysis of solid deposits from the surface choke of one of the Iranian carbonate oil fields showed that they consisted of 41.3 wt % …

Efficient Text Bounding Box Identification Using Mask R-Cnn: Case Of Thai Documents, Phanthakan Kiatphaisansophon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Text detection is a fundamental task in computer vision, particularly for Optical Character Recognition (OCR) application. This research focuses on text detection part of the OCR. Our previous text detection model, CRAFT (Character-Region Awareness For Text detection) has shown promising outcomes in bounding box identification. Nevertheless, it encounters issues associated with post-processing and multiline text. The post-processing related to the necessity to reconfigure the model when new documents are introduced, resulting in inefficiencies and complexities. Also the CRAFT model tends to blend bounding boxes from consecutive lines, introducing errors and impacting the accuracy in the text recognition part of the …

Laser-Induced Biochar For The Solid-Phase Extraction Of Organophosphorus Pesticides, Sherwin Hugo Tan Lu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biochar is a carbon-rich material made from the combustion of biomass. It is a potential sustainable material for preconcentration sorbents, however conventional research uses energy-intensive pyrolysis methods to produce biochar sorbents. In this study, a more energy-efficient approach, using a laser irradiation process under ambient conditions, was studied to produce a biochar sorbent for the solid-phase extraction (SPE) of organophosphorous pesticides (OPPs) and analyzed by gas chromatography-mass spectrometry (GC-MS). Various biomass materials rich in lignin were tested to produce a biochar by a laser irradiation method. Cork sheet had the most consistent production of a laser-induced biochar and was selected …

Tenvr: Matlab-Based Toolbox For Environmental Research, Aleksandar I. Goranov, Rachel L. Sleighter, Dobromir A. Yordanov, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the advancements in science and technology, datasets become larger and more multivariate, which warrants the need for programming tools for fast data processing and multivariate statistical analysis. Here, the MATLAB-based Toolbox for Environmental Research "TEnvR" (pronounced "ten-ver") is introduced. This novel toolbox includes 44 open-source codes for automated data analysis from a multitude of techniques, such as ultraviolet-visible, fluorescence, and nuclear magnetic resonance spectroscopies, as well as from ultrahigh resolution mass spectrometry. Provided are codes for processing data (e.g., spectral corrections, formula assignment), visualization of figures, calculation of metrics, multivariate statistics, and automated work-up of large datasets. TEnvR allows …

Extracting High-Molecular Weight Dna From Cyanobacteria Using Promega's Wizard® Hmw Dna Extraction Kit With A Modified Protocol, Metis, Megan A. Hept, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Extraction of high molecular weight (HMW) DNA for long read sequencing with little to no fragmentation and high purity is difficult to acquire from cyanobacterial species. Here we describe a modified method of extraction using Promega's Wizard® HMW DNA Extraction Kit to acquire high molecular weight DNA from cyanobacterial species. The protocol used in the kit is the “3.D. Isolating HMW DNA from Gram-Positive and Gram-Negative Bacteria” protocol. During a key step in the protocol, the lingering remnants of the mucilage layer of the cyanobacterial species is removed, preventing it from sticking to the DNA pellet produced. This customized modification …

Abiotic Stress Mitigation: A Case Study From 21 Trials Using A Natural Organic Matter Based Biostimulant Across Multiple Geographies, Rachel L. Sleighter, Terry Hanson, David Holden, Kristen M. Richards

Chemistry & Biochemistry Faculty Publications

Crop productivity and yields can be greatly diminished by abiotic stress events including drought, extreme temperatures, excess moisture, and saline irrigation water. Multiple stressors occurring simultaneously can further exacerbate the strain on plants. Various types of biostimulants have been shown to mitigate abiotic stress and here, the results of 21 trials on corn, wheat, soybean, and various high-value crops are discussed in the context of the abiotic stress that either occurred naturally or was experimentally induced. Treatments in these trials included stressed and non-stressed plants, as well as either an untreated control or grower standard fertilizer applications alone and in …

Investigation Of Ch4 Adsorption And Activation On Modified Metalloporphyrin Graphene Sheets, Brianna Haase

Masters Theses

Finding a good catalyst for C-H bond breaking is important due to the rise of natural gas and crude oil emissions. From 2000-2006, CH4 emission concentrations stabilized, but in 2007, it sharply started increasing again. For example, atmospheric CH₄ levels were 1886.37 ppb in July 2021 but this rose to 1904.52 ppb in just one year. Precious metal catalysts, such as Ir systems, have been used for C-H bond breaking, but are not sustainability ideal as they are costly to produce and have a significant carbon footprint. Because of this, less expensive 3d metal catalysts have risen in investigative …

Development And Biological Evaluation Of Selective Small-Molecule Inhibitors Of The Human Cytochrome P450 1b1, Austin Hachey

Theses and Dissertations--Chemistry

The human cytochrome P450 1B1 (CYP1B1) is an emerging target for small- molecule therapeutics. Several solid tumors overexpress CYP1B1 to the degree that it has been referred to as a universal tumor antigen. Conversely, its expression is low in healthy tissues. CYP1B1 may drive tumorigenesis through promoting the formation of reactive toxins from environmental pollutants or from endogenous hormone substrates. Additionally, the expression of CYP1B1 in tumors is associated with resistance to several common chemotherapies and with poor prognoses in cancer patients. However, inhibiting CYP1B1 with small molecules has been demonstrated in cellular and murine model systems to reverse this …

Discovery Of Acetyl Coa Synthetase And Sars-Cov-2 Protease Inhibitors, Taiwo Elijah Esan

Graduate Research Theses & Dissertations

There is an urgent need for new antifungal drugs. Acetyl CoA synthetases (ACSs) are Acyl-CoA/NRPS/Luciferase (ANL) superfamily enzymes that couple acetate with CoA to generate acetyl CoA, a key component of central carbon metabolism in eukaryotes and prokaryotes. Normal mammalian cells are not dependent on ACSs, while tumor cells, fungi, and parasites rely on acetate as a precursor for acetyl CoA. Consequently, ACSs have emerged as a potential drug target. This body of work focuses on the inhibition of the Acetyl CoA synthetase enzyme in fungal species. This work has involved designing and synthesizing compounds that are potential fungal ACS1 …

Materials And Interfaces Of Electrochemical Energy Storage And Conversion, Siyuan Gao

Graduate Research Theses & Dissertations

Batteries with higher energy density and safe properties are demanded in modern society. This dissertation comprehensively studies the materials and interfaces of electrochemical energy storage and conversion for lithium-sulfur (Li-S) batteries as well as aqueous zinc-manganese dioxide (Zn-MnO2) batteries to fundamentally meet the renewable energy demands.This dissertation is divided into 2 sections. The first section (chapter 2-4) describes the electrodes and electrolyte modification for Li-S batteries. Specifically, chapter 2 describes sulfur cathodes’ modification by utilization of Fe3O4 and Nitrogen(N)-doped carbon cloth as sulfur host. Results show that synergistic effects of Fe3O4 and N-carbon bring strong adsorption toward lithium polysulfide and …

Computational Studies Of The Effects Of Substitutions On Silatranes And Ring Strain Energies, As Well As Determination Of Aromaticity And Complexation In Polypnictogen Analogues Of The Cyclooctatetraenyl Dianion, Alexander Stuart Pixler

Graduate Research Theses & Dissertations

The work in this dissertation computationally examines four areas involving variations on archetype molecules and how they affect reactivity and physical properties. Studies in Chapters 2 and 3 assess substituent effects on cyclic systems, while those in Chapters 4 and 5 explore both partial and complete substitution of ring component atoms as well as the chemical implications of the substitution.The effect of substituents on molecular reactivity is a critical concept that affects every branch of chemistry. Previous work within our group showed that 1-hydridosilatrane was an effective and selective reducing agent for a variety of compounds. Fully 3,3,7,7,10,10-substituted silatranes have …

Drug Delivering Properties Of Novel Materials For Dentinal Desensitization, Abu Ahammadullah

Dissertations and Theses

This study focuses on the development of non-toxic dental materials that can adhere to dentin, occlude dentinal tubules, and release a drug with or without biological triggers. The properties of those materials are examined by SEM, UV-vis absorption spectroscopy, and a fluoride-selective electrode. The study also investigates the surface modification of calcium carbonate surface with casein, which stabilizes its micro-and nanoparticles in aqueous suspensions, making them suitable for use in dentifrices. The results indicate that the morphology and composition of the particles affect their ability to hold and release eugenol, with the casein-coated calcium carbonate microspheres being the most acid-sensitive …

Modulatory Effects Of Deacetylated Sialic Acids (A Sugar Residue) In Nk-Mediated Cytotoxicity And Targeted Therapy By Receptor Tyrosine Kinase Inhibitors, Mathias Tawiah Anim

Electronic Theses and Dissertations

The complex nature of the biology of cancer is still an unraveling science, yielding several biomarkers that have served as molecular targets for detection and treatment of the disease. How sugars, glycans, play a role has remained relatively uninvestigated. Sialic acid (Sia), a sugar residue on the surface of cells, has been identified as a hallmark of cancer and its progression. Sialic acid can be highly functionalized, but we became interested in acetylated Sias. This functional group is modulated by Sialate O- acetylesterase (encoded by the gene SIAE) and Sialate O-acetyltransferase (encoded by CASD1), enzymes that play a crucial role …

Design, Synthesis, And Evaluation Of Acetyl Coa Synthetase Inhibitors, Michael Emmett Heene

Graduate Research Theses & Dissertations

Invasive fungal species provide a challenge to the current drug landscape, only partiallymet by approved drugs. The Acetyl Coenzyme Synthetase (ACS) enzymes are an attractive target for antifungal compounds because normal mammalian cells do not rely on ACS for energy metabolism while fungal cells do rely on ACS. This work focuses on the design and synthesis of inhibitors of various fungal ACS enzymes. The first class of inhibitors is based on the 2-aminothiazole scaffold originating from a saturation transfer difference (STD) nuclear magnetic resonance (NMR) study and previous whole-organism assays. Ultimately, the 2-aminothiazole core compounds were found to not be …

The Indivisible System: Modeling The Metal-Pterin-Dithiolene System In Molybdenum And Tungsten Cofactors, Cassandra Gates

Bryn Mawr College Dissertations and Theses

Mo and W enzymes are ubiquitous in living organisms and crucial for sustaining life. Mo and W enzyme variety is diverse, but they contain a highly conserved aspect of functionality in these enzymes, the pyranopterin-dithiolene (PDT) ligand. A total of eight possible electron redox equivalents occurs between the metal center and PDT, making the molybdenum cofactor (Moco) and the tungsten cofactor (Tuco) the most redox rich cofactors in all of biology. This research focuses on the development of new pterin-dithiolene synthetic modeling systems for Moco. The knowledge gained from the characterization of these compounds is applied to the enzymes, furthering …

Rapid Generation Of P(V)-F Bonds Through The Use Of Sulfone Iminium Fluoride Reagents, Lucy P. Miller, James A. Vogel, Shiraz Harel, Jenna M. Krussman, Patrick R. Melvin

Chemistry Faculty Research and Scholarship

Phosphorus–fluorine bonds have become increasingly relevant in the pharmaceutical industry. To continue their exploration, more efficient synthetic methods are needed. Here, we report the application of sulfone iminium fluoride (SIF) reagents to the synthesis of P(V)–F bonds. The SIF reagents promote the deoxyfluorination of phosphinic acids in just 60 s with excellent yields and scope. The same P(V)–F products can also be synthesized from secondary phosphine oxides using an SIF reagent.

Isolation And Identification Of Chlorate-Reducing Hafnia Sp. From Milk, William P. Mccarthy, Meghana Srinivas, Martin Danaher, Christine O'Connor, Tom F. O'Callaghan, Douwe Van Sinderen, John Kenny, John T. Tobin

Articles

Chlorate has become a concern in the food and beverage sector, related to chlorine sanitizers in industrial food production and water treatment. It is of particular concern to regulatory bodies due to the negative health effects of chlorate exposure. This study investigated the fate of chlorate in raw milk and isolated bacterial strains of interest responsible for chlorate breakdown. Unpasteurized milk was demonstrated to have a chlorate-reducing capacity, breaking down enriched chlorate to undetectable levels in 11 days. Further enrichment and isolation using conditions specific to chlorate-reducing bacteria successfully isolated three distinct strains of Hafnia paralvei . Chlorate-reducing bacteria were …