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Stability Of Polyethylene Glycol-Coated Copper Nanoparticles And Their Optical Properties, Deborah Okyere, Ryan H. Manso, Xiao Tong, Jingyi Chen

Chemistry & Biochemistry Faculty Publications and Presentations

Oxidation is a corrosion reaction where the corroded metal forms an oxide. Prevention of oxidation at the nanoscale is critically important to retain the physicochemical properties of metal nanoparticles. In this work, we studied the stability of polyethylene glycol (PEG) coated copper nanoparticles (PEGylated CuNPs) against oxidation. The freshly-prepared PEGylated CuNPs mainly consist of metallic Cu which are quite stable in air although their surfaces are typically covered with a few monolayers of cuprous oxide. However, they are quickly oxidized in water due to the presence of protons that facilitate oxidation of the cuprous oxide to cupric oxide. PEG with …

Editorial: Engineering Nucleic Acids-Based Functional Nanomaterials, Nanodrugs, And Biosensors, Jabrane Jouha, Fengli Li, Wen-Ta Su, Chenguang Fan, Dayong Yang, Hai Xiong

Chemistry & Biochemistry Faculty Publications and Presentations

Editorial on the Research Topic: Engineering Nucleic Acids-Based Functional Nanomaterials, Nanodrugs, and Biosensors

Analysis Of The Zebrafish Olfactory System Using Immunohistochemistry And Enhanced Techniques Of Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Tara Lynn Maser

Dissertations

Desorption electrospray ionization (DESI-MS) is an ambient ionization technique where the sample is analyzed directly from a surface with very minimal sample preparation under ambient conditions and follows ESI-like ionization mechanisms. DESI-MS has proven powerful in analyzing or imaging lipids and other small molecules directly from biological samples and even allows for subsequent histological staining and analyses. However, DESI-MS is less widely used for protein analysis due to a lack of sensitivity and the complex diversity of proteins in biological samples.

A major goal of this research has been to obtain new neurobiological knowledge by combining histology and mass spectrometry …

Synthesis And Characterization Of Nanojars And Their Anion Binding Ability, Wisam Abdulabbas Flayyih Al Isawi

Dissertations

Inorganic anions are an important class of inherently negatively charged species. Anions such as sulfate (SO42–) and phosphates (H2PO4–, HPO42–) are ubiquitous in nature and biological systems, whereas chromate (CrO42–) and arsenates (H2AsO4–, HAsO42–) are environmental pollutants. Because of the high interest in the sequestration of anions from aqueous media, different methods have been explored to bind anions. Among these, the use of noncovalent interactions to encapsulate anions by organic and metal-organic host molecules is particularly attractive, because the reversibility of binding allows for the easy recovery of the extracted anion and the recycling of the anion extracting agent.

Nanojars …

Development Of Novel Mass Spectrometric Methods For Reaction Screening, Oligosaccharide Detection, And Nitrosamine Quantitation, Qi Wang

Dissertations

Benefitting from its high detection sensitivity and specificity, mass spectrometry (MS) has become a powerful technique in academia and industry. The aim of this dissertation study is to develop new mass spectrometric methods for organic reaction screening, detection of oligosaccharide/glycan in complex matrices, and nitrosamine absolute quantitation.

First, an electrochemistry/mass spectrometry (EC/MS) platform is built to generate an N-cyclopropylaniline radical cation electrochemically and to monitor its reactivity toward alkenes, which leads to the discovery of a new redox neutral reaction of intermolecular [3 + 2] annulation of N-cyclopropylanilines and alkenes. Net redox neutral electrosynthesis is quite rare in synthetic organic …

Bodipy-Based Light-Responsive Materials, Zhaoxiong Wan

Dissertations

The energy required for life on our planet is provided by light. In science, light is an important and powerful tool for measuring and modifying substances. For example, under the effect of illumination, light-responsive materials can change their physical and chemical properties. Photochemistry is a branch of research to study the effects of light irradiation on chemical structures and reactions. Some photochemical changes could lead to chemical bond dissociation (such as in photosynthesis) and structure isomerization (such as in the retina). Photochemistry has a strong relationship with human lives and it is essential in many ways. Among photophysics, fluorescence emission …

Advanced Cnc/Peg/Pdmaa Semi-Ipn Hydrogel For Drug Delivery Management In Wound Healing, Samia Afrin, Md. Shahruzzaman, Papia Haque, Md. Sazedul Islam, Shafiul Hossain, Taslim Ur Rashid, Tanvir Ahmed, Makoto Takafuji, Mohammed Mizanur Rahman

Department of Chemistry: Faculty Publications

A Semi Interpenetrating Polymer Network (semi-IPN) hydrogel was prepared and loaded with an antibiotic drug, gentamicin, to investigate the wound healing activity of this system. The semi-IPN hydrogel was synthesized by combining natural polymer cellulose nanocrystal (CNC) and synthetic polymer polyethylene glycol (PEG) and poly (N,N0-dimethyl acrylamide) (PDMAA), which was initially added as a monomer dimethyl acrylamide (DMAA). CNC was prepared from locally obtained jute fibers, dispersed in a PEG-NaOH solvent systemand then mixed with monomer DMAA, where polymerization was initiated by an initiator potassium persulphate (KPS) and cross-linked by N,N0-methylenebisacrylamide (NMBA). The size, morphology, biocompatibility, antimicrobial activity, thermal and …

Development Of The Chemistry Mindset Instrument (Chemi) For Use With Introductory Undergraduate Chemistry Students, Deborah L. Santos, Jack Barbera, Suazette R. Mooring

Chemistry Faculty Publications and Presentations

Chemistry education research has increasingly considered the role of affect when investigating chemistry learning environments over the past decade. Despite its popularity in educational spheres, mindset has been understudied from a chemistry-specific perspective. Mindset encompasses one's beliefs about the ability to change intelligence with effort and has been shown to be a domain-specific construct. For this reason, students’ mindset would be most relevant in chemistry if it were measured as a chemistry-specific construct. To date, no instrument has been developed for use in chemistry learning contexts. Here we present evidence supporting the development process and final product of a mindset …

Electrochemical Voltammetric Behavior Of Sulfur Mustard On The Bare Pt Electrode, Yu-Lin Yang, Jie Sun, Tian Zhou, Ji-Gang Li, Shou-Ping Wei

Journal of Electrochemistry

The sulfur mustard (bis(2-chloroethyl) sulphide, HD), one of highly toxic chemical weapon agents, can damage the alive tissue cells (such as skin, lung, respiratory mucosa and so on), and cause carcinogenic and mutagenic effects for a long time exposure, which imposes a great threat not only to the human health, but also to the sustainable development of the society. With its convenience, high sensitivity and rapid response, electrochemical technology exhibits considerable potential in the field-deployed detection toward HD, but the related reports are rare. Herein, the electrochemical behavior of HD on the bare Pt electrode was investigated by electrochemical measurements, …

Biofouling Behaviors Of Pure Titanium Surface Polarized At Different Potentials, Zhao-Xia Dai, Da-Jiang Zheng, Guang-Ling Song, Dan-Qing Feng, Pei Su

Journal of Electrochemistry

Titanium (Ti) and its alloys are commonly used as engineering materials. Although they have been widely used in marine environments, they are also facing serious threats of biofouling. Therefore, it is necessary to investigate the relationship between electrochemical behavior and bioaffinity of titanium oxide film in seawater to explore effective surface treatment technology to reduce biofouling. In this work, the cathodic potential of -0.8 V_SCE and the passivation potential of 0.5 V_SCE were directly applied to the TA2 Ti in artificial seawater for potentionstatic polarization treatment to prepare two kinds of surface films with different states and then …

Targeting Heat Shock 27 Kda Protein Induces Androgen Receptor Degradation, Yaxin Li

ETD Archive

Glioblastoma (GBM) is the most common and aggressive brain tumor, with very poor prognosis. Androgen receptor (AR) plays a significant role in the progression of GBM, and anti-androgen agents have the potential to be used for the treatment of GBM. However, AR mutation commonly happens in GBM, which makes the anti-androgen agents less effective. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein to stabilize AR. Inhibition of HSP27 results in AR degradation regardless the mutation status of AR, which makes HSP27 a good target to abolish AR in GBM. Identified compound I ((N-(3-((2,5-dimethoxybenzyl)oxy)-4-(methylsulfonamido) phenyl)-4-methoxybenzamide) inhibits GBM cell …

Cysteine Metallochemistry And Metal Binding: Quantification Of The Thermodynamic Foundations Of Cellular Homeostasis, Matthew R. Mehlenbacher

Dartmouth College Ph.D Dissertations

Metals are required for life. Many metalloproteins contain cysteine in their metal-binding site (MBS) and cysteines are unique in that they are reactive, and strongly bind certain metals, which aid in metal selectivity and specificity. Using isothermal titration calorimetry (ITC), the thermodynamic foundation for metal binding, cellular protection, and transcriptional regulation, which all utilize cysteines in their MBS, are quantified.

In bacteria there are metalloprotein pathways that actively uptake mercury, which are regulated by the metalloregulatory protein MerR. MerR de-represses the transcription of these mer proteins in a metal-dependent manner. Using ITC, the thermodynamic foundation of the negative allosteric coupling …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Isolation And Genome Analysis Of An Amoeba-Associated Bacterium Dyella Terrae Strain Ely Copper Mine From Acid Rock Drainage In Vermont, United States, Lesley Ann Giddings, Kevin Kunstman, Bouziane Moumen, Laurent Asiama, Stefan Green, Vincent Delafont, Matthew Brockley, Ascel Samba-Louaka

Chemistry: Faculty Publications

Protozoa play important roles in microbial communities, regulating populations via predation and contributing to nutrient cycling. While amoebae have been identified in acid rock drainage (ARD) systems, our understanding of their symbioses in these extreme environments is limited. Here, we report the first isolation of the amoeba Stemonitis from an ARD environment as well as the genome sequence and annotation of an associated bacterium, Dyella terrae strain Ely Copper Mine, from Ely Brook at the Ely Copper Mine Superfund site in Vershire, Vermont, United States. Fluorescent in situ hybridization analysis showed this bacterium colonizing cells of Stemonitis sp. in addition …

Utilizing Novel Field And Data Exploration Methods To Explore Hot Moments In High-Frequency Soil Nitrous Oxide Emissions Data: Opportunities And Challenges, Christine S. O'Connell, Tyler L. Anthony, Melanie A. Mayes, Tibisay Pérez, Debjani Sihi, Whendee L. Silver

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Soil nitrous oxide (N₂O) emissions are an important driver of climate change and are a major mechanism of labile nitrogen (N) loss from terrestrial ecosystems. Evidence increasingly suggests that locations on the landscape that experience biogeochemical fluxes disproportionate to the surrounding matrix (hot spots) and time periods that show disproportionately high fluxes relative to the background (hot moments) strongly influence landscape-scale soil N₂O emissions. However, substantial uncertainties remain regarding how to measure and model where and when these extreme soil N₂O fluxes occur. High-frequency datasets of soil N₂O fluxes are newly possible …

Synthesis Of Diaryl And Alkyl-Aryl Ethers Via Diaryl Iodonium Reagents, Rory Tennessee Gallagher

Dissertations and Theses

Substituted benzenoid rings are a prevalent motif in many industries including high tech, agrochemicals, and pharmaceuticals. As a result, the arylation of chemical compounds is a highly sought-after chemical transformation. There are many literature methods to achieve this chemical transformation, nucleophilic aromatic substitution and transition metal catalysis are both widely used and studied. Diaryliodonium salt mediated chemistry is an attractive alternative to these methods as it does not require the expensive toxic metals and designer ligands of transition metal catalysis and is not restricted to electron deficient aryl rings with specific substitution patterns like nucleophilic aromatic substitution.

Many diaryliodonium salt …

Understanding The Effects Of Temperature On Electrostatic Dna Denaturation, Jeffrey Taylor

Master's Theses

In this work, the electrostatic denaturation of 18-bp DNA duplexes was investigated via Square Wave Voltammetry (SWV) to determine the extent of melting (∆) and rate of melting (𝝉). Electrostatic denaturation was observed over the temperature range of 20-50 °C, and purely electrostatic melting was defined from 27.5°C. In contrast, electrostatic denaturation for 30 °C was defined as a mixture of thermal melting thiol desorption + electrostatic melting. Electrostatic denaturation is a temperature-dependent process, and the amount of melting of the dsDNA increased with temperature. It was also observed that the ∆ and 𝝉 values increase with temperature further …

Extending The Application Of Polyol-Induced Extraction For The Analysis Of Glucocorticoids And Nsaids In Water Using Uhplc-Ms/Ms, Shipra Patel

Seton Hall University Dissertations and Theses (ETDs)

Polyol induced extraction (PIE) is an extraction technique developed and patented by Sowa Jr., Murphy, and Deshpande at Seton Hall University as a method of removal of water from acetonitrile. PIE is a technique that separates water from a mixture containing an organic liquid and water by adding a polyol to the mixture that leads to phase separation of aqueous and organic phase. The goal of this work was to extend the application of PIE and to demonstrate that PIE can be an alternative method for extraction of glucocorticoids and non-steroidal anti-inflammatory drugs (NSAIDS) which then can be analyzed using …

Cell‑Controlled Dynamic Surfaces For Skeletal Stem Cell Growth And Differentiation, Hilary J. Anderson, Jugal Kishore Sahoo, Julia Wells, Sebastiaan Van Nuffel, Hala S. Dhowre, Richard O. C. Oreffo, Mischa Zelzer, Rein V. Ulijn, Matthew J. Dalby

Advanced Science Research Center

Skeletal stem cells (SSCs, or mesenchymal stromal cells typically referred to as mesenchymal stem cells from the bone marrow) are a dynamic progenitor population that can enter quiescence, self-renew or differentiate depending on regenerative demand and cues from their niche environment. However, ex vivo, in culture, they are grown typically on hard polystyrene surfaces, and this leads to rapid loss of the SSC phenotype. While materials are being developed that can control SSC growth and differentiation, very few examples of dynamic interfaces that reflect the plastic nature of the stem cells have, to date, been developed. Achieving such interfaces is …

Synthesis, Characterization, And Bioactivity Of 3-Substituted Coumarins As An Undergraduate Project, Karsen King, Nicholas Campbell, Ronald Okoth, Wathsala Medawala

Georgia Journal of Science

Coumarins are an important class of phytochemicals, a chemical defense presumed to be secreted by plants. More recently, Coumarins have gathered popularity for their basis in anti-cancer agents. This paper dives into the organic synthesis of two 3-substituted coumarins from o-vanillin using the Knoevenagel condensation reaction. The 3-substituted coumarin were characterized using melting point analysis, ¹H-NMR, and UV-Vis spectroscopy. In addition, the anticancer activity of synthesized 3-substituted coumarin compounds were assayed against topoisomeraseIIα, which is the target enzyme of FDA approved anti-cancer drug etoposide since it is an active enzyme in cancer cell replication. The demonstrated procedures can be …

Dr. Lawrence J. Berliner, Anit Tyagi

DU Undergraduate Research Journal Archive

An interview with Dr. Lawrence J. Berliner.

Du Undergraduate Showcase: Research, Scholarship, And Creative Works: Abstracts, Emma Aggeler, Elena Arroway, Daisy T. Booker, Justin Bravo, Kyle Bucholtz, Megan Burnham, Nicole Choi, Spencer Cockerell, Rosie Contino, Jackson Garske, Kaitlyn Glover, Caroline Hamilton, Haley Hartmann, Madalyne Heiken, Colin Holter, Leah Huzjak, Alyssa Jeng, Cole Jernigan, Chad Kashiwa, Adelaide Kerenick, Emily King, Abigail Langeberg, Maddie Leake, Meredith Lemons, Alec Mackay, Greer Mckinley, Ori Miller, Guy Milliman, Katherine Miromonti, Audrey Mitchell, Lauren Moak, Megan Morrell, Gelella Nebiyu, Zdenek Otruba, Toni V. Panzera, Kassidy Patarino, Sneha Patil, Alexandra Penney, Kevin Persky, Caitlin Pham, Gabriela Recinos, Mary Ringgenberg, Chase Routt, Olivia Schneider, Roman Shrestha, Arlo Simmerman, Alec Smith, Tessa Smith, Nhi-Lac Thai, Kyle Thurmann, Casey Tindall, Amelia Trembath, Maria Trubetskaya, Zachary Vangelisti, Peter Vo, Abby Walker, David Winter, Grayden Wolfe, Leah York

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Showcase.

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Simulating Photo-Disintegration Of 137cs Radioactive Waste Using Various Energies Of Gamma Photons, Hassanain H. Alkazzaz, Asia H. Al-Mashhadani, Kamal H. Lateef

Karbala International Journal of Modern Science

In this study, the possibility of using gamma-ray in photo-disintegration method was examined so that it can be used in the remediation of 137Cs radionuclides waste materials by nuclear transmutation to convert long-lived nuclides to other isotopes nuclides, which are shorter half-life (or stable), by different photo-nuclear reaction channels (γ,n), (γ,2n), (γ,p), (γ, a), (γ,d). A simulation code has been written using MATLAB for conducting calculations of reduction and residual. The results showed that gamma-ray fluxes below 1017 [cm-2 s-1] are not adequate to perform effective incinera-tion of 137Cs, and as for gamma flux of 1018 [cm-2 s-1] it showed …

Engineering Of A Multi-Epitope Subunit Vaccine Against Sasrs-Cov-2 Through The Viroinformatic Approach, Aamir Shehzada, Christijogo Sumartono, Jusak Nugraha, Helen Susilowatid, Andi Yasmin Wijayab, Hafiz Ishfaq Ahmad, Wiwiek Tyasningsih, Fedik Abdul Rantam

Karbala International Journal of Modern Science

The COVID-19 outbreak has infected millions of people worldwide, but no vaccine has been discovered to combat it efficiently. This research aims to design a multi-epitope vaccine using highly efficient B- and T-cell epitopes from the SARS-CoV-2 Surabaya isolate through a viroinformatic approach. First, the putative epitopes were linked together to develop tertiary structures and then docked with toll-like receptor 4 (TLR-4) that demonstrated a robust interaction with a low eigenvalue of 4.816138 e-06. Furthermore, the structure's high immunogenic response was observed and successfully cloned into the expression vector pET28a (+). This implies that the designed vaccine can prove effective …

The Evaluation Of Radiometal Labeled Biomolecules For Imaging And Therapeutic Applications, Truc Huynh

Arts & Sciences Graduate Student Theses and Dissertations

Radiometals play a crucial role in nuclear medicine for the diagnosis and therapy of various diseases including cancer and neurological disorders. In fact, there is a broad range of radiometals that are currently in use for imaging and therapy such as 99mTc, 89Zr, 68Ga, 177Lu, and 64/67Cu. Radiometal use in nuclear medicine has been stimulated by advances in radionuclide production that allow for fast, reliable, and cost-efficient production and an extensive understanding of molecular targets and tumor biomarkers. In recent years, there has been a growing interest in theranostics - the combination of imaging and therapy related to the same …

Synthesis, Characterization And Cellular Uptake Of Magnesium Complexes Of Pyrones And Amino Acids, Derek Robert Case

Dissertations - ALL

This thesis focuses on the treatment of micronutrient deficiency, specifically hypomagnesemia, through the synthesis and solution- and solid-state characterization of "pharma grade", biorelevant magnesium complexes (nutraceuticals) utilizing short-chain peptides (di- and tri-), pyrones, and amino acids. There is further emphasis placed on determining the in vitro uptake of all produced complexes. This work aims to mitigate the shortcomings of current magnesium supplements and better illustrate an understanding of the factors impacting magnesium uptake. Specifically, 1) There is a paucity of information regarding the coordination of biorelevant ligands to magnesium, most of which was investigated between the 1950s and 1980s, and …

Monitoring Bacteria Cultures Using Near Infrared (Nir) Binary Spectronephelometry (Bsn), Raman Spectra And Principal Component Analysis (Pca), Steven Ortiz

Dissertations - ALL

Current noninvasive methods cannot continuously and simultaneously monitor the concentrations of cells and media components that define the state of native bacterial cultures, because of changing turbidity. A new technique, binary spectronephelometry (BSN) has the same or better sensitivity and precision for population monitoring as optical density at 600nm (OD600), while simultaneously measuring metabolic processes. The BSN algorithm uses laser induced emission to probe mildly turbid media i.e., propagation of light occurs in the single scattering regime. A BSN "training set" associates a grid of elastic emission measurements, comprising Rayleigh and Mie scattering, and inelastic emission measurements, comprising fluorescence and …

Trichloroacetimidates As Outstanding Electrophiles For The Carbon-Nitrogen, Carbon-Oxygen And Carbon-Carbon Bonds Formation And Synthetic Studies Of Protein Phosphatase-5 (Pp5) Small Molecule Inhibitors, Nilamber Mate

Dissertations - ALL

Trichloroacetimidates have been previously used for glycosidic bond formation in carbohydrate chemistry and in Friedel-Craft reactions. Traditionally, trichloroacetimidates had be synthesized using an alcohol and strongly basic conditions, but in recent years milder preparation methods have been reported. Given the ease of preparation of these versatile reagents, their chemistry has been explored intensely in recent years. While few reported methods suggest they can react under promoter free conditions, activation by Lewis or Brønsted acid leads to a formation of a carbocation from benzylic trichloroacetimidates. Work described herein makes use of these convenient carbocation precursors for new reactions.Isatin is an ambidentate …

Signaling Studies Of Protein-Peptide Binding On Microelectrode Arrays, Kendra White

Arts & Sciences Graduate Student Theses and Dissertations

Electrochemical methods provide unique opportunities for non-traditional synthesis and analytical studies. Using electrochemistry, we are able to synthesize individually addressable molecular surfaces on microelectrode arrays and then utilize the surface to probe interactions between receptors and their biological targets. To date, cyclic voltammetry signals can be used to detect biological interactions between proteins and small molecules on the surface of an array, however those signals are often amplified by the presence of a large number of small molecules by any given electrode. This amplification makes it difficult to obtain binding data using the arrays that can be compared with existing …