Digital Commons Network^™

Elemental Composition And Arsenic Speciation Analysis Of Processed Seafood Products Using Atomic Spectrometric Techniques, Austin A. Roberts

Legacy Theses & Dissertations (2009 - 2024)

Arsenic (As) is a widely known toxic element that is highly ubiquitous and has been detected in soil, sediment, naturals waters, the atmosphere, and in organisms of the 5 kingdoms. The toxicity of As however, is dependent on the molecular form in which it takes as well as the route of exposure. For the general population, exposure to As mainly takes place via ingestion of food and water, which have led to numerous studies investigating As and it’s various species in these matrices. Seafood is one of the major sources of dietary exposure to As and has thus led to …

Biochemical And Chemical Methods Of Key Derivation For Cryptographic Ciphers, Leif K. Mcgoldrick

Legacy Theses & Dissertations (2009 - 2024)

Cryptography is a vital component of digital communication and digital data in general. The use of cryptography is necessary to support the veracity of data and to protect it from outside parties with malicious intent. Cryptography focuses on two main facets that are vital for this goal: data encryption and user authentication. Encryption protects the data by transforming it into an encrypted text that would not allow someone access without having or breaking the encryption method that was used to make it. User authentication is a multiple part process that allows for one to be able to identify oneself to …

Utilizing Raman Spectroscopy And Chemometrics For Novel Medical Diagnostic Purposes, Nicole M. Ralbovsky

Legacy Theses & Dissertations (2009 - 2024)

Many problems exist within the myriad of currently employed diagnostic techniques. Further, an incredibly wide variety of procedures are used to identify an even greater number of diseases which exist in the world. There is a definite unmet clinical need to improve the diagnostic capabilities of these methods, including improving test sensitivity and specificity, objectivity and definitiveness, and reducing cost and how invasive a test is, with an interest in replacing multiple diagnostic methods with one powerful tool. That is, the development of a singular technique which can accurately and objectively diagnose a wide variety of diseases in a cost-effective …

Nmr Based Studies Of Interactions Between Ribosomes And Glycolytic Enzymes, Devin Bryan Busch

Legacy Theses & Dissertations (2009 - 2024)

Recent research has been performed to better understand what implications ribosome-mediated quinary interactions have on cellular growth. These studies demonstrated that ribosomal binding to enzymes, and their cofactors, can cause significant changes in their enzymatic activity leading to a proposal that ribosome surfaces play a greater regulatory in cellular growth than thought of in the past. To widen the scope of investigations performed on these ribosomal-mediated quinary interactions, the regulatory enzymes associated in glycolysis (hexokinase, phosphofructokinase, and pyruvate kinase) were titrated into a solution of 70S E. coli ribosome and analyzed via 1H-15N-HSQC NMR. The perturbations of the peaks associated …

Development Of Dual Functional Dna/Rna Nanostructures For Drug Delivery, Vibhav Amit Valsangkar

Legacy Theses & Dissertations (2009 - 2024)

In addition to the traditional biochemical functions, DNA and RNA have been increasingly studied as building blocks for the formation of various 2D and 3D nanostructures. DNA has emerged as a versatile building block for programmable self-assembly. DNA-based nanostructures have been widely applied in biosensing, bioimaging, drug delivery, molecular computation and macromolecular scaffolding. A variety of strategies have been developed to functionalize these nanostructures. The major advantage is that DNA is a very stable molecule and its base-pairing properties can be easily utilized to control and program the formation of desired nanostructures. In addition, some of these DNA/RNA nanostructures have …

Mixed-Valent Heterometallic Molecular Precursors : Expansion Into 4d Transition Metals, Jesse Caleb Carozza

Legacy Theses & Dissertations (2009 - 2024)

Hydrogen fuel can provide an ideal carbon-free energy carrier wherever water is available, be that on Earth or throughout the solar system. The use of water electrolysis to split water molecules into contaminant-free hydrogen gas, suitable for use in fuel cells, and oxygen gas allows also for storage of excess electrical energy during periods of high production and low demand, and an easy path to release that stored energy when demand is high and active supply is low. However, liberating hydrogen from water is an energy-intensive process, and effective electrocatalysts that reduce the amount of energy wasted by the reaction …

Bioaffinity-Based Methods For Forensic, Biometric, And Clinical Purposes, Mindy Elizabeth Hair

Legacy Theses & Dissertations (2009 - 2024)

Biomarker analysis is a well-established discipline that involves the evaluation of biological samples for the presence of various substances indicative of personal attributes or illnesses. Sweat is one example of a biological fluid that is often overlooked for forensic and clinical analyses, even though it can contain DNA, various amino acids, and other low molecular weight compounds.1–3 The work presented in this dissertation focuses on the use of bioaffinity-based assays to quantify biomarkers in sweat for both forensic and clinical applications. The concentration of the biochemical content within an individual’s sweat are controlled by hormone-based metabolic pathways4 that fluctuate daily …

Metabolic Changes Associated With Adaptive Resistance To Daptomycin In Streptococcus Mitis-Oralis, Allison Parrett, Joseph M. Reed, Stewart G. Gardner, Nagendra N. Mishra, Arnold S. Bayer, Robert Powers, Greg A. Somerville

Department of Chemistry: Faculty Publications

Background: Viridans group streptococci of the Streptococcus mitis-oralis subgroup are important endovascular pathogens. They can rapidly develop high-level and durable non-susceptibility to daptomycin both in vitro and in vivo upon exposure to daptomycin. Two consistent genetic adaptations associated with this phenotype (i.e., mutations in cdsA and pgsA) lead to the depletion of the phospholipids, phosphatidylglycerol and cardiolipin, from the bacterial membrane. Such alterations in phospholipid biosynthesis will modify carbon flow and change the bacterial metabolic status. To determine the metabolic differences between daptomycin-susceptible and non- susceptible bacteria, the physiology and metabolomes of S. mitis-oralis strains 351 (daptomycin-susceptible) and 351-D10 (daptomycin …

Application Of Synthesized Copper Nanoparticles Using Aqueous Extract Ofziziphus Mauritiana L. Leaves As A Colorimetric Sensor For The Detection Of Ag$^{+}$, Roomia Memon, Ayaz Ali Memon, Syed Tufail Hussain Sherazi, Siraj Uddin, Aamna Balouch, Muhammad Raza Shah, Sarfaraz Ahmed Mahesar, Kauser Rajar, Muhammad Hassan Agheem

Turkish Journal of Chemistry

The presented work demonstrates the preparation of copper nanoparticles (CuNPs) via aqueous leaves extract of Ziziphus mauritiana L. (Zm) using hydrazine as a reducing agent. Various parameters such as volume of extract, concentration of hydrazine hydrate, concentration of copper chloride, and pH of the solution were optimized to obtain Ziziphus mauritiana L. leaves extract derived copper nanoparticles (Zm-CuNPs). Brownish red color was initial indication of the formation of Zm-CuNPs while it was confirmed by surface plasmon resonance (SPR) band at wavelength of 584 nm using ultraviolet-visible (UV-vis) spectroscopy. Synthesized Zm-CuNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron …

Corrosion And Wear Behaviour Of Highly Porous Ti-Tib-Tin$_{\Mathbf{X}}$ In Situ Composites In Simulated Physiological Solution, Fati̇h Toptan

Turkish Journal of Chemistry

Highly porous Ti matrix composites can be a solution for some of the major clinical concerns for the load bearing implants such as low tribocorrosion resistance, stress shielding, and lack of biological anchorage. In order to respond to these needs, highly porous Ti-TiB-TiN$_{x}$ in-situ composites were synthesized by pressureless sintering using BN as reactant and urea as space holder. Corrosion behaviour was investigated at body temperature, in phosphate buffer saline solution (PBS), by measuring open circuit potential (OCP) and cyclic polarization. Wear behaviour was studied in PBS by reciprocating against a 10 mm diameter alumina ball under 3 N of …

Soil Degradation And Erosion, Anthany Ravanh

Natural Sciences Student Research Presentations

No abstract provided.

Development Of Analytical Methods For Toxic Inhaled Hazards (Tih) And Their Metabolites, Obed Adu Gyamfi

Electronic Theses and Dissertations

Toxic inhalation hazards (TIHs), such as methyl isocyanate (MIC) and hydrogen cyanide (HCN), are noxious gases and vapors that are harmful, and often deadly, to humans. However, because of their low cost and high reactivity, they are extensively used for industrial productions, creating risk of exposure for both industrial workers (e.g., occupational exposure) and civilians (e.g., accidental release during transport). The illicit use of TIHs, including as terrorist agents, is also concerning. Considering the rapid toxicity of TIHs and the danger they pose to both human and animal lives, there is a critical need to develop of analytical methods for …

Synthesis And The Genetic Encoding Of Novel Lysine Post-Translational Modifications, Sahan A. Galbada Liyanage

Theses and Dissertations

Post-translational modifications (PTMs) play a significant role in regulating cell signaling and regulating the inner cellular environment. The study of PTMs and their primary biological functions is critical for the development of new medicines targeting the pathways and biomolecules responsible for the PTMs.

Previous studies revealed the direct coupling of the β -hydroxybutyryl lysine (K_BHB) modification with the gene expression. K_BHB in histone proteins links metabolism to epigenetics and gene expression and enables to study in-depth, how cell metabolism controls the gene expression and vice versa. Similar novel histone modification, K_Lac, attracts a special interest …

Synthesis Of Bradyrhizose And The Equatorial Glycosides Of 3-Deoxygenation-D-Mango-Oct-2-Ulosonic Acid, Philemon O. Ngoje

Wayne State University Dissertations

ABSTRACT

SYNTHESIS OF BRADYRHIZOSE AND THE EQUATORIAL GLYCOSIDES OF 3- DEOXY-D-MANNO-OCT-2-ULOSONIC ACID

Chapter one provides a general view on the background to the research in two parts. The first part begins with an introduction on the significance of the lectin-carbohydrate interactions in leguminous plants. Then the structure and role of O-antigen lipopolysaccharides in the symbiotic nitrogen cycle, and the mechanism and significance of the cycle in leguminous plants growth are introduced. The role, isolation and characterization of bradyrhizose are also introduced; and the previous syntheses of bradyhizose and of related bicyclic compounds presented.

The second part of chapter one starts …

Route Exploration And Synthesis Of The Reported Pyridone-Based Pdi Inhibitor Stk076545, Eric Greve, Sergey V. Lindeman, Christina Scartelli, Lin Lin, Robert Flaumenhaft, Chris Dockendorff

Chemistry Faculty Research and Publications

The enzyme protein disulfide isomerase (PDI) is essential for the correct folding of proteins and the activation of certain cell surface receptors, and is a promising target for the treatment of cancer and thrombotic conditions. A previous high-throughput screen identified the commercial compound STK076545 as a promising PDI inhibitor. To confirm its activity and support further biological studies, a resynthesis was pursued of the reported β-keto-amide with an N-alkylated pyridone at the α-position. Numerous conventional approaches were complicated by undesired fragmentations or rearrangements. However, a successful 5-step synthetic route was achieved using an aldol reaction with an α-pyridone allyl …

Antifungal Defense Molecules From Bacterial Symbionts Of North American Trachymyrmex Ants, Georgia Scherer

CMC Senior Theses

Defensive symbioses, in which microbes provide molecular defenses for an animal host, hold great potential as untapped sources of therapeutically useful antibiotics. Fungus-growing ants use antifungal defenses from bacterial symbionts to suppress pathogenic fungi in their nests. Preliminary chemical investigations of symbiotic bacteria from this large family of ants have uncovered novel antifungal molecules with therapeutic potential, such as dentigerumycin and selvamicin.

In this study, the bacterial symbionts of North American Trachymyrmex fungus-growing ants are investigated for antifungal molecules. Plate-based bioassays using ecologically-relevant fungal pathogens confirmed that these bacteria have antifungal activity. In order to purify and identify the antifungal …

Nonheme Iron–Thiolate Complexes As Structural Models Of Sulfoxide Synthase Active Sites, Danushka M. Ekanayake, Anne A. Fischer, Maya E. Elwood, Alexandra M. Guzek, Sergey V. Lindeman, Cordina V. Popescu, Adam T. Fiedler

Chemistry Faculty Research and Publications

Two mononuclear iron(II)–thiolate complexes have been prepared that represent structural models of the nonheme iron enzymes EgtB and OvoA, which catalyze the O₂-dependent formation of carbon–sulfur bonds in the biosynthesis of thiohistidine compounds. The series of Fe(II) complexes reported here feature tripodal N₄ chelates (L^A and L^B) that contain both pyridyl and imidazolyl donors (L^A = (1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)methanamine; L^B = N,N-bis((1-methylimidazol-2-yl)methyl)-2-pyridylmethylamine). Further coordination with monodentate aromatic or aliphatic thiolate ligands yielded the five-coordinate, high-spin Fe(II) complexes [Fe^II(L^A)(SMes)]BPh …

Structural Dynamics Of Inosine Triphosphate Pyrophosphatase (Itpa) Protein And Two Clinically Relevant Mutants: Molecular Dynamics Simulations, Yao Houndonougbo, Bethany Pugh, Kandise Vanwormer, Caitlin April, Nicholas Burgis

Chemistry and Biochemistry Faculty Publications

The inosine triphosphate pyrophosphatase (ITPA) protein is responsible for removing noncanonical purine nucleoside triphosphates from intracellular nucleotide pools. Absence of ITPA results in genomic instability and increased levels of inosine in DNA and RNA. The proline to threonine substitution at position 32 (P32T) affects roughly 15% of the global population and can modulate treatment outcomes for cancer, lupus, and hepatitis C patients. The substitution of arginine with cysteine at position 178 (R178C) is extremely uncommon and has only been reported in a small cohort of early infantile encephalopathy patients suggesting that a functional ITPA protein is required for life in …

Benzoporphyrin-Based Photosensitizing Nanocomposites For Optoelectronic Applications, Wittawat Keawsongsaeng

Chulalongkorn University Theses and Dissertations (Chula ETD)

A new series of meso-bifunctionalized benzoporphyrin derivatives bearing a p-diphenylaminophenylethynyl and a p-carboxylphenylethynyl meso-groups, and 2 p-carboxyl groups in a trans-fashion on a benzoporphyrin core is successfully synthesized and characterized by spectroscopic techniques. Impact of electron-donating diphenylamino and electron-withdrawing surface-anchoring carboxyl groups on photophysical and electrochemical properties of the target benzoporphyrins was investigated in comparison with those of their benchmark analog containing one carboxylphenylethylnyl and three phenyl meso-groups by UV-visible spectrophotometry and cyclic voltammetry. The results show that while the p-carboxylphenylethynyl group give electronic contribution to the molecules by lowering energy gap, a role of the p-diphenylaminophenylethynyl group is found …

Dye-Encapsulated Ethyl Cellulose As Fluorescence Sensor For Aldehyde Detection, Jinnawat Jongkhumkrong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Over past years, even though lung cancer as one of vital cancer-related mortalities worldwide has inevitably exhibited the highest death rate of entire cancers, there is no facile and convenient diagnosis approaches. The previous researches have reported about long-chain aldehyde compounds such as hexanal, heptanal, octanal, and nonanal as the crucial biomarkers of lung cancer. Nevertheless, the sensing platform for long-chain aldehyde detection have been rarely reported. In this research, the helicene dye-encapsulated ethyl cellulose (EC@dye-NH) nanosensors have achieved the potentially sensitive and specific detection of long-chain aldehyde in aqueous media. As a proof-of-concept, the intrinsic hydrazine group of dye-NH …

Optimization Of Dapoxyl Aptamer For Label-Free Bioanalysis, Jack E. Mordeson, Ryan P. Connelly, Pedro F. Madalozzo, Yulia Gerasimova

Digital Repository: Showcase of Undergraduate Research Excellence

No abstract provided.

Synthesis Of Guanidines From Thioureas Using Photocatalyst, Trin Sae-Tan

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, a photo catalytic guanylation is investigated using Ru(bpy)3Cl2 as a photocatalyst under visible light irradiation. The reaction can be performed in green solvent such as ethanol and water and non-toxic K2CO3 base using 1-5% of Ru(bpy)3Cl2 under 19W white LED irradiation. Under optimized condition, this method can be applied for guanylation of various thioureas carrying a variety of functional groups with morpholine. Moreover, the amine scope includes primary and secondary amine carrying various functional groups. As the result, more than twenty examples of guanidine products can be produced in fair to excellent yields. Moreover, the reaction can …

Antibiotic Drug Nanocarriers For Probing Of Multidrug Abc Membrane Transporter Of Bacillus Subtilis, Pavan Kumar Cherukuri, Preeyaporn Songkiatisak, Feng Ding, Jeam-Michel Jault, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Multidrug membrane transporters can extrude a wide range of substrates, which cause multidrug resistance and ineffective treatment of diseases. In this study, we used three different sized antibiotic drug nanocarriers to study their size-dependent inhibitory effects against Bacillus subtilis. We functionalized 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm silver nanoparticles (Ag NPs) with a monolayer of 11-amino-1-undecanethiol and covalently linked them with antibiotics (ofloxacin, Oflx). The labeling ratios of antibiotics with NPs are 8.6 × 10², 9.4 × 10³, and 6.5 × 10⁵ Oflx molecules per NP, respectively. We designed …

Molecular Nature Of Marine Particulate Organic Iron-Carrying Moieties Revealed By Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (Esi-Fticrms), Chen Xu, Peng Lin, Luni Sun, Hongmei Chen, Wei Xing, Manoj Kamalanathan, Patrick G. Hatcher, Maureen H. Conte, Antonietta Quigg, Peter H. Santschi

Chemistry & Biochemistry Faculty Publications

Marine sinking particulate organic matter (POM), acting as a link between surface primary production and burial of organic matter in marine sediments, undergoes a variety of physical and biochemical alterations on its way to the deep ocean, resulting in an increase in its un-characterizable proportion with diagenesis. Further, the binding ligands in POM for iron, an essential nutrient to marine life and tightly coupled with organic matter, has rarely been studied. In the current study, we employed an approach combining sequential extraction with ultrahigh resolution mass spectrometry (ESI-FTICRMS), in order to explore and unravel the chemical characteristics of organic matter …

Oxidation Of Aldehydes To Nitriles With An Oxoammonium Salt: Preparation Of Piperonylonitrile, Nathaniel D. Kaetzel, Kyle M. Lambert, Christopher B. Kelly

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has recently been recognized as a candidate for monitoring chemical changes in the rhizosphere. The information it provides about nutrient diffusion may improve nitrogen use efficiency, leading to enhanced management and success of restoration projects. The objective of this study was to determine the efficacy of microdialysis sampling to quantify the relative recoveries (RR%) of nitrate-N and ammonium-N, the two inorganic nitrogen compounds typically found in soil. The effects of microdialysis flow rate, sample medium concentration, and the presence of both analytes in solution on the relative recoveries obtained from …

Enhanced Glucose Electrooxidation At Ni-Cu Binary Oxide Nanocatalyst, Islam M. Al-Akraa, Mahmoud M. Abouzaid Eng, Yaser M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

The aim of this study is to fabricate a nickel (NiOx) and copper (CuOx) oxide nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Cu/GC) for glucose oxidation (GO). A sequential electrodepositon mode was applied to assemble NiOx and CuOx in the fabrication scheme. The optimization of Ni loading on the GC surface (will be abbreviated as Ni/GC electrode) was achieved first to attain the maximum catalytic efficiency in terms of the specific current toward GO. This (409 Ag1)was obtained by applying 15 mC/cm2 in the deposition of Ni. However, unfortunately the NiOx/GC could not support a long-term …

Development Of Novel Adsorbent For Industrial Waste Water Treatment, Islam M. Al-Akraa, Hassan M. Shehata Eng, Dalia A. Ali Eng., Hoda A. Elsawy Dr

Chemical Engineering

The main objective of this research project is to perform some experimental procedures to inform the ability of the novel adsorbent used in this project. The chemical modification of the adsorbent is the chemical oxidation of pure powder chitosan using some specific redox pairs which are potassium dichromate and sodium bisulphite. After preparing the modified chitosan, there are some parameters that must be discussed during the adsorption process. The first parameter is the time parameter, showing experimentally the optimum time for adsorption under certain conditions by collecting values of absorbance and concentration of thymol blue adsorbed after the process from …

Ni-Au Anodic Nano-Electrocatalyst For Direct Glucose Fuel Cells, Islam M. Al-Akraa, Aya S. Abdulhalim Eng, Yassr M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

This study aims at the sequential assembling of a nickel oxide (NiOx: cauliflower-like nanostructure, 90 nm) and gold (Au; spherical, 95 nm in an average particle size) onto the GC surface nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Au/GC) for the glucose electro−oxidation (GO); the principal anodic reaction in the direct glucose fuel cells (DGFCs). The charge of the Ni deposition on the GC surface (will be abbreviated as Ni/GC electrode) was initially optimized to obtain the highest catalytic activity toward GO which attained at (339.8 Ag−1) by applying 15 mC in the Ni deposition. Yet, …

Quantum Biology? From Dna Point Mutations To Fibril Formation In Alzheimer Disease, Eduardo Romero Camacho

Electronic Theses and Dissertations, 2020-2023

In the '60s, Löwdin explored the realm of Quantum Biology. Löwdin defined Quantum Biology as the use of quantum mechanics to study the activity and molecular properties of biologically active molecules such as DNA, RNA, and proteins. This dissertation aims to describe molecules of biological interest such as DNA base pairs and amyloid-beta peptides and treat them using a quantum mechanical approach. We used electronic structure methods to achieve the quantum biological nature of these molecules under our computational power, tools, and techniques. In chapter 2, we present the quantum mechanical description of the spontaneous mutations in DNA base pairs …