Chemistry Commons^™

Introduction Of Human Acidic Fibroblast Growth Factor (Fgf1) Variant With Increased Stability And Bioactivity, Azadeh Tavousi Tabatabaei

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1) involves in a broad spectrum of biological processes, including cell growth, proliferation, differentiation, migration, angiogenesis, wound healing, and embryonic development. hFGF1 non-selectively binds to cell surface hFGF receptor isoforms to elicit these cell-signaling processes. Since hFGF1 plays a significant role in tissue repair activity, that is a prime candidate for novel wound healing therapeutics. However, hFGF1 has been found to unfold near physiological temperature due to a strong electrostatic repulsion created by a dense cluster of positively charged amino acids near the c-terminus. The problem not only leads to proteolytic degradation of the …

Control Of Irradiation Wavelength And Quantum Yield Of Photocleavable Cages, Jingxuan Ma

Theses and Dissertations

An important component of biological research is the precise regulation of biomolecules in their physiological environment. Recent advances in neuroscience, have made it possible to regulate the activity of neurotransmitters using photocleavable protecting groups (PPGs), which are also known as cages. This enables the use of light as a trigger to activate selected neurons via photo release of agonists with precise control of timing as well as synaptic site, popularly referred to as spatiotemporal control. In recent years, a variety of PPGs have been developed and applied to biomolecular cages. PPGs can be classified according to their absorption wavelengths (from …

Synthesis And Characterization Of Ternary Pt Nanoally Catalysts For Fuel Cells, Ylith Peck

Undergraduate Honors Theses

A hydrogen fuel cell is an electrochemical device that converts oxygen and hydrogen into electrical energy while producing water as the only by-product, which has attracted growing interest, especially in the automotive industry. This technology is efficient and has zero pollution to the environment, in contrast to the direct use of fossil fuels in combustion engines which produce pollution and greenhouse gas emissions. One of the key components for hydrogen fuel cells is the catalyst that operates at the cathode, which currently use platinum. Due to the scarce amount of platinum in the world, the manufacturing cost for fuel cells …

The Dissolution And Recovery Of Critical Materials (Li2co3 And Uf6) From Ionic Liquid, Cassara Higgins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lithium and uranium are critical materials in both the energy industry and for national security. Lithium is necessary for the next generation of batteries and 6Li is valuable for the production of tritium necessary for both fusion energy and to maintain our nuclear stockpiles. Uranium is a fuel source or precursor fuel source for commercially operating nuclear fission power. The monitoring of uranium hexafluoride (UF6) enrichment at foreign facilities is important for the monitoring of nuclear safeguards and enforcement of non-proliferation treaties. Recovery methods for lithium at the end of life of batteries are necessary to ensure abundance of the …

Revisiting The Chemistry Of Uranium And Rhenium Fluorides: Implication To Fuel Cycle And Nuclear Forensics Science, James Amos-Aimé Louis-Jean

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fluorine plays a major role in the nuclear industry where F2(g) and HF(g) are critical to the preparation of UF6 and UF4. These materials are prepared for uranium enrichment to increase the isotopic concentration of 235U. During separation efforts, the isotope 99Tc (a high yield fission product, 6.1% from 235U) is extracted along with uranium and can be converted to binary technetium fluorides (i.e., TcF4, TcF6) during re-enrichment of used uranium material. This provides a route for 99Tc to reenter the reactor environment and affect the nuclear properties of fuel pellets made with reprocessed uranium. The objective of this work …

Stability, Electronic Structure, And Nonlinear Optical Properties In Clusters And Materials: A Synergistic Experimental-Computational Analysis, Maksim Kulichenko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of Chemistry as a science is an understanding of how and why certain atoms are bonded together and what effects these bonds cause. Modern computational chemistry offers a wide range of tools that greatly assist the exploration of vast chemical space replacing expensive trial-and-error experimental approaches. Computational chemistry may serve to characterize newly synthesized compounds and provide atomic scale insights inaccessible to experimentalists’ vision. Moreover, predictive power of computational chemistry may be used as a guidance for future experiments and for the rational design of new compounds with desired properties.

This dissertation demonstrates the capabilities of joint …

Multi Elemental Analysis Of Cannabis Oil Based Products Using Icpms And Microwave Assisted Digestion., Kevin Trevon Marchbanks-Owens

Theses (2016-Present)

Due to the presence of CBD-(cannabidiol), bioavailable elements as well as industry versatility and relatively low levels of toxicity to the environment. CBD oils have driven the overall demand for Cannabis based plant products in the commercial and medical sector. However, dependent upon the environmental circumstances upon which these plants are grown can leave them susceptible to toxic heavy metal exposure. In fact, the natural metabolism of Cannabis plants makes them a hyperaccumulator of trace metals. This creates a severe health risk for CBD product consumers especially for more vulnerable populations with pre-existing conditions. Furthermore, the risk of heavy metal …

Analysis Of Polychlorinated Biphenyls In Electric Transformer Oil Using Gas Chromatography With Electron Capture Detector., Vivek Mann

Theses (2016-Present)

Polychlorinated biphenyls (PCB’s) are a group of synthetic chemicals which are environmentally insistent that were once used as coolants and lubricants in paints, heat transfer fluids, transformers, capacitors, caulking materials and other electrical materials owning to their property of good insulators. PCBs are persistent organic pollutants since they are persistent, resistant to biodegradation, bioaccumulate and have shown to cause a variety of deleterious effects on human health and the environment. Due to this the manufacturing of PCBs was banned in the United States in 1977. Although, production of PCBs has reportedly stopped, the potential or actual release of PCBs into …

Synthesis And Characterization Of Silver Thione Complexes, Audrey V. Lawrence

Honors Theses

Coordination polymers are repeating units of a coordination complex that have applications as catalysts, conductors, and magnets. In this work, silver (I) was the metal of choice because it behaves similarly to copper (I), which has been studied much more extensively and thione ligands were chosen due to their potential for forming coordination polymers. These coordination complexes with silver were synthesized by combining silver nitrate with thioacetamide, N,N'-diphenylthiourea, and 2-mercapto-1-methylimidazole. These complexes were characterized via IR spectroscopy, elemental analysis, and X-ray crystallography. Silver thioacetamide was determined to form a coordination complex through the sulfur to form a trigonal crystal lattice …

Target Of Glut4 Regulating Protein Tug-Ubl1 To Treat Insulin Resistant Type Two Diabetes, Megan Kohout

Chemistry Student Work

Type two diabetes mellitus is a highly prevalent disease for which the mechanism of insulin signaling to initiate glucose uptake in cleaving TUG-UBL1 by the protease Usp25m is currently not well understood. As increased insulin resistance can lead to the development of type one insulin deficient diabetes, the knowledge of this pathway may uncover underlying causes of insulin resistance. This research aims to understand the effect and stoichiometry of Usp25m binding to TUG-UBL1 in relationship to the cleavage of TUG-UBL1 initiating translocation of GLUT4 glucose transporter. The action of protease effector PIST will be investigated to understand the importance of …

Bis(Tryptophan) Amphiphiles: Design, Synthesis And Efficacy As Antimicrobial Agents, Michael Mckeever

Dissertations

Amphiphiles play important roles in nature. These molecules contain both hydrophilic and hydrophobic regions, leading to some astonishing properties. The lipid bilayer of the cell membrane is a fascinating organization of amphiphilic phospholipids. Natural and synthetic amphiphiles, such as antimicrobial peptides, interact with the cell membrane. Such interactions can impact transport of molecules across the cell membrane, disrupting cell functions. In this work, a library of tryptophan-containing amphiphiles was synthesized and their antimicrobial properties were explored.

First, a library of bis(tryptophan) amphiphiles was synthesized. Preparation included a coupling reaction of a diamine with tryptophan residues, via their carboxy-termini, at …

Design, Synthesis, And Analysis Of Paired Coiled-Coil Peptidic Molecular Building Blocks Used For Linearly Controlled Self-Assembly Of Α-Helical Coiled-Coil Heterodimer Peptide Pairs, Jason Distefano

Chemistry Theses

Molecular building blocks are fundamental to biological synthesis and processes and have been utilized in advanced materials, drugs and drug delivery systems, and biotechnology. Proteins have been used as molecular building blocks for the construction of complex, well-ordered structures. Coiled-coil protein domains are essential subunits used for the oligomerization of protein complexes, gene expression, and structural elements of biological materials. The synthesis and assembly of proteins utilizing coiled-coil motifs are of great scientific interest due to their potential applications in disease treatment, biomechanical motors, nanoscale delivery systems, etc. However, assembling protein complexes with specific morphology is still challenging because …

Synthesis And Study Of Unsymmetrical Bidentate Bis(Phosphino)Pyrrole Ligands And Their Transition Metal Complexes, Julia F. Vidlak

Honors Theses

Our laboratory has reported the synthesis and characterization of a broad library of unsymmetrical bidentate bis(phosphino)pyrrole (BPP) ancillary ligands for use in nickel-catalyzed cross-coupling reactions. The electronic and steric properties of nickel complexes bearing these ligands are examined, and our data support the hypothesis that these ligands produce nickel complexes with electron-deficient metal centers. The syntheses of (BPP)Ni(o-tolyl)Cl precatalysts for utilization in nickel-catalyzed Buchwald-Hartwig Amination are described, and preliminary reactivity studies reveal that (BPP)Ni(o-tolyl)Cl precatalysts are effective in promoting C–N cross-coupling reactions. Finally, we report steric measurements and electronic properties obtained from computed (BPP)NiCl2 and (BPP)Ni(CO)2 complexes, respectively. Additional reactivity …

Investigation On Electrochemical Processes Of P-Aminothiophenol On Gold Electrode Of Nanostructures, Hui-Yuan Peng, Jia-Zheng Wang, Jia Liu, Huan-Huan Yu, Jian-De Lin, De-Yin Wu, Zhong-Qun Tian

Journal of Electrochemistry

Electrochemical reactions on nanostructured noble electrodes have received much attention, however, the reaction mechanism and reaction kinetics are still difficult to be studied. Probe molecule can give an insight to the investigation of electrochemical reactions on noble electrodes with nanostructures. In this paper, the electrochemical process of p-aminothiophenol (PATP) adsorbed on the gold electrode was studied by electrochemical cyclic voltammetry and surface-enhanced Raman spectroscopy (SERS). Here, we used one-step sodium citrate reduction method (Frens method) to synthesize gold nanoparticles, which are used to construct the nanostructured gold electrode. The Raman electrolytic cell used was based on the traditional three-electrode electrolytic …

Study On Electrochemical Conversion Of Ammonium Sulfate To Ammonium Persulfate In Acetylpyrazine Wastewater, Yi-Jie Wang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

Acetylpyrazine is an important spice and also plays important roles in biology, medicine and other fields. However, the wastewater containing ammonium persulfate, ferric ion (Fe³⁺), pyrazine, and a large amount of ammonium sulfate was produced during the production of acetylpyrazine. In this study, ammonium sulfate in acetylpyrazine wastewater was electrolytically converted into ammonium persulfate for economic benefits. Using platinum as an anode and graphite as a cathode, the influence factors of the electrolysis process (including the composition of the anolyte, the current density, the temperature, etc.) were firstly investigated without interference from other compositions. Under the optimal condition, …

Study On Electrodeposition Of Antimony In Choline Chloride-Ethylene Glycol Eutectic Solvent, Hao Wang, Xiao-Zhou Cao, Xiang-Xin Xue

Journal of Electrochemistry

Antimony is a chemically stable metal that has been widely used in industry, military and other fields. The use of electrodeposition to prepare antimony coating has the advantages of simple operation and low cost. The deep eutectic solvent (DES) is a eutectic mixture composed of a hydrogen bond donor and a hydrogen bond acceptor at a fixed molar ratio. It has the advantages of wide electrochemical window, high thermal stability, easy preparation, and low cost. Selecting DES as the electrolyte for electrodeposition can avoid the hydrogen evolution reaction of the aqueous system and the toxicity of ionic liquids. In recent …

Adjusting The Alloying Degree Of Pt3Zn To Improve Acid Oxygen Reduction Activity And Stability, Tian-En Zhang, Ya-Ni Yan, Jun-Ming Zhang, Xi-Ming Qu, Yan-Rong Li, Yan-Xia Jiang

Journal of Electrochemistry

Proton exchange membrane fuel cell (PEMFC) is a new type of energy device, a relatively excellent way to achieve carbon neutrality. However, due to the relatively slow reaction rate of oxygen reduction reaction (ORR) at the cathode, platinum (Pt) is the key material of the cathode catalyst. However, Pt is a kind of noble metal, and its high cost restricts the PEMFC commercialization process. At present, the main approach is to combine transition metals with Pt to prepare Pt-based alloys and to reduce the use of Pt. Pt-based alloys are excellent catalysts for ORR, improving both the activity and stability, …

Effects Of Electrode Shape On Lithiation Process Of Lithium-Ion Battery Electrodes, Shi-Wei Sun, Jian-Jun Nie, Yi-Cheng Song

Journal of Electrochemistry

This paper studies the influence of electrode shape on the lithiation process of lithium ion batteries. Both experimental observation and numerical simulation are employed to investigate the competitive interaction between the diffusion of lithium ions in both solid and liquid phases and the lithium intercalation reaction at the electrode surface. Experimental cells were prepared with the anode and cathode being placed parallel, leaving the latter embracing the former. An experimental device based on CCD camera was set up for in situ observation of electrode lithiation. The lithiation levels of the graphite anodes were estimated according to the observed color profile. …

Electrochemical Degradation Of Oxytetracycline Catalyzed By Fe3O4 Magnetic Nanoparticles, Fang Ying, Shan-Shan Xu, Yan-Bing Xu, Miao-Miao Liang, Jian-Feng Li

Journal of Electrochemistry

The purpose of this study is to optimize the electrochemical degradation of oxytetracycline (OTC) in water using a low cost and simple preparation method. In this paper, the Fe₃O₄ magnetic nanoparticles were used as catalysts to activate the electrochemical oxidation system of peroxydisulfates (PDS) which acted as electrolytes to provide active free radicals in order to improve the degradation of OTC under the condition of applying current. As one of the tetracycline antibiotics (TCs), OTC is one of the most used antibiotics in the world, therefore, it is necessary to study the effective degradation of OTC. By …

Preparation Of Pt@Basrtio3 Nanostructure And Its Properties Towards Photoelectrochemical Ammonia Synthesis, Jing Zhang, Rui-Xia Guo, Jian-Jun Fu, Shi-Bin Yin, Pei-Kang Shen, Xin-Yi Zhang

Journal of Electrochemistry

Ammonia is an important industrial raw material and a potential green energy. Using renewable energy to convert nitrogen into ammonia under ambient condition is an attractive method. However, the development of efficient photoelectrochemical ammonia synthesis catalysts remains a challenge. Perovskite such as BaSrTiO₃ (BST) is a good photocatalytic material. However, BST is active under ultraviolet light and has a high recombination rate of photogenerated electron-hole pairs. By dispersing precious metals, it can effectively regulate the absorption of sunlight by BST. In this work, we used a two-step method to prepare BST. The H₂PtCl₆·6H₂O …

Multi-Scale Simulation Revealing The Decomposition Mechanism Of Electrolyte On Lithium Metal Electrode, Yan-Yan Zhang, Yue Liu, Yi-Ming Lu, Pei-Ping Yu, Wen-Xuan Du, Bing-Yun Ma, Miao Xie, Hao Yang, Tao Cheng

Journal of Electrochemistry

Lithium metal is considered as an ideal anode material for next-generation high energy density batteries with its high specific capacity and low electrode potential. However, the high activity of lithium metal can lead to a series of safety issues. For example, lithium metal will continuously react chemically with the electrolyte, forming unstable the solid electrolyte (SEI) films. In addition, lithium dendrites can be formed during cycling, which can puncture the SEI film and cause short circuits in the battery. These drawbacks greatly hinder the commercial application of lithium metal. To solve the above problems, it is important to understand the …

Synthesis Of Modified Walnut Shell Biochar And Material Characterization In Ground Water Treatment, Maaike Parajes, Suraj Pochampally

Undergraduate Research Symposium Posters

Biochar (BC) is a carbon-rich material synthesized from the pyrolysis of biomasses and developed to remove soil and wastewater contaminants. The pyrolysis process involves thermally decomposing the organic materials in the absence of oxygen. Biochar has the potential to be an eco-friendly and effective adsorbent for heavy metals and toxic organic compounds. An adsorbent is a material that attracts other substances on its surface, chemically and physically. Walnut shells were chosen for the biochar modification to improve the surface morphology, pore structure, and adsorption capability.

Synthesis, Characterization, And Thermal Investigation Of Metal Phosphites And Potential Implications For Astrobiology, Kimberly Faye Meyberg

Master of Science in Chemical Sciences Theses

The role of phosphorus in biochemistry is well understood. However, the route by which phosphorus was incorporated into early biomolecules on the prebiotic Earth is uncertain. Phosphate, the most prevalent species of phosphorus found in Earth’s geological record, is insoluble and unreactive with organics in aqueous environments. While the most abundant biogenic elements (C, N, H, O, and S) can be found in a volatile phase under terrestrial conditions, phosphorus cannot, suggesting that minerals must have been the main sources of phosphorus on the early Earth. One possible explanation is that phosphite was a major source of reduced, reactive phosphorus …

Foldamers Reveal And Validate Therapeutic Targets Associated With Toxic Α-Synuclein Self-Assembly, Jemil Ahmed, Tessa C. Fitch, Courtney M. Donnelly, Johnson A. Joseph, Tyler D. Ball, Mikaela M. Bassil, Ahyun Son, Chen Zhang, Aurélie Ledreux, Scott Horowitz, Yan Qin, Daniel Paredes, Sunil Kumar

Chemistry and Biochemistry: Faculty Scholarship

Parkinson’s disease (PD) is a progressive neurodegenerative disorder for which there is no successful prevention or intervention. The pathological hallmark for PD involves the self-assembly of functional Alpha-Synuclein (αS) into non-functional amyloid structures. One of the potential therapeutic interventions against PD is the effective inhibition of αS aggregation. However, the bottleneck towards achieving this goal is the identification of αS domains/sequences that are essential for aggregation. Using a protein mimetic approach, we have identified αS sequences-based targets that are essential for aggregation and will have significant therapeutic implications. An extensive array of in vitro, ex vivo, and in vivo assays …

Evaluating Alternative Ebullition Models For Predicting Peatland Methane Emission And Its Pathways Via Data–Model Fusion, Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, Yiqi Luo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding the dynamics of peatland methane (CH4) emissions and quantifying sources of uncertainty in estimating peatland CH4 emissions are critical for mitigating climate change. The relative contributions of CH4 emission pathways through ebullition, plant-mediated transport, and diffusion, together with their different transport rates and vulnerability to oxidation, determine the quantity of CH4 to be oxidized before leaving the soil. Notwithstanding their importance, the relative contributions of the emission pathways are highly uncertain. In particular, the ebullition process is more uncertain and can lead to large uncertainties in modeled CH4 emissions. To improve model simulations of CH4 emission and its pathways, …

Low-Cost Adsorbent For Disinfection Byproduct Removal From Drinking Water, Savanna Vacek, Suraj Pochampally

Undergraduate Research Symposium Posters

Disinfection byproducts (DBPs) are harmful contaminants that are unintentionally created in disinfected water after chlorination. Activated carbon, often expensive and difficult to acquire in low-income and rural areas, has previously been used to remove DBPs from drinking water. Biochar is made from agricultural waste (i.e. feedstock) and has been identified as a low-cost yet effective adsorbent to remote contaminants from drinking water. This work focuses on the efficacy of biochar and activated carbon to remove DBPs from drinking water for the purpose of treating drinking water after emergency chlorination. This study has the potential to help water distributors and disadvantaged …

Identification Of Lipid Species: Potential Biomarkers For Early Detection Of Hepatocellular Carcinoma, Kit Yee Leung, Kaylee Freitas

Undergraduate Research Symposium Posters

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. HCC is associated with cirrhosis. Poor survival rate of HCC is due to diagnosis of HCC at late stage.

Biochar Hydrophilicity Characterization By A Smartphone-Based Apparatus: Design, Construction, And Measurement Calibration, Emma Letourneau, Suraj Pochampally

Undergraduate Research Symposium Posters

Water contact angles are used to determine hydrophilicity, which is a material's attraction to water. A water contact angle of greater than 90 degrees indicates a hydrophobic material that repels water, whereas a contact angle of less than 90 degrees indicates a hydrophilic material [Fig. 1]. Water contact angles are measured through a goniometer, which can cost between $2000 to $10,000.

Biochar is a porous carbon material created from biological waste products, that is pyrolyzed (i.e. burned) in a low-oxygen, high heat environment. Biochar can be used to remove contaminants from water and remediate soil while reusing waste, making it …

Carbohydrate Metabolism In Bacteria: Alternative Specificities In Adp-Glucose Pyrophosphorylases Open Novel Metabolic Scenarios And Biotechnological Tools, Jaina A. Bhayani, Maria Josefina Iglesias, Romina I. Minen, Antonela E. Cereijo, Miguel Ballicora, Alberto A. Iglesias, Matias D. Asencion Diez

Chemistry: Faculty Publications and Other Works

We explored the ability of ADP-glucose pyrophosphorylase (ADP-Glc PPase) from different bacteria to use glucosamine (GlcN) metabolites as a substrate or allosteric effectors. The enzyme from the actinobacteria Kocuria rhizophila exhibited marked and distinctive sensitivity to allosteric activation by GlcN-6P when producing ADP-Glc from glucose-1-phosphate (Glc-1P) and ATP. This behavior is also seen in the enzyme from Rhodococcus spp., the only one known so far to portray this activation. GlcN-6P had a more modest effect on the enzyme from other Actinobacteria (Streptomyces coelicolor), Firmicutes (Ruminococcus albus), and Proteobacteria (Agrobacterium tumefaciens) groups. In addition, we …

New Chemoselective Dehydration And Cyclization Strategies Enabled By Triphosgene, Moshood Oreofeoluwa Ganiu

LSU Doctoral Dissertations

Since Friedrich Wöhler’s synthesis of urea in 1828, the techniques of organic synthesis have developed and advanced greatly. This advancement has facilitated the discovery of new organic synthetic methods, and enabled access to a more expansive chemical space. The purpose of this dissertation is to present the development of new organic synthetic reactions that were uncovered through previous discoveries. Additionally, the main theme of this work relies on exploiting the versatility of triphosgene in organic synthesis. To this end, the developed chemistries rely on the ability of triphosgene to serve as an activating agent, and a chloride source.

Chapter 1 …