Analytical Chemistry Commons^™

The Tetrafluoroborate Salt Of 4-Methoxybenzyl N-2-(Dimethylamino)Ethyl-N-Nitrosocarbamate: Synthesis, Crystal Structure And Dft Calculations, Helene Hedian, Vladimir Benin

Chemistry Faculty Publications

The tetrafluoroborate salt of 4-methoxybenzyl N-2-(dimethylamino)ethyl-N-nitrosocarbamate was prepared in two steps, via the corresponding carbamate. Its crystal structure is monoclinic, space group P21/c. The unit cell dimensions are: a = 19.499(8) Å, b = 5.877(3) Å, c = 15.757(7) Å, α = 90°, β = 110.019(7)°, γ = 90°, V = 1696.5(12) Å3, Z = 4. The structure exhibits an unexpected, pseudo-gauche conformation with respect to the C2–C3 bond, due to a stabilizing hydrogen bond between the carbonyl oxygen (O1) and the hydrogen atom at the trialkylammonium center (H3n), with a distance between them of …

Visualizing The Spatial Localization Of Active Matrix Metalloproteinases (Mmps) Using Maldi Imaging Ms, Sasirekha Muruganantham

Graduate Theses and Dissertations

Biomaterial implantation induces the foreign body response (FBR). Development of longer-term implants relies on the thorough understanding of the FBR. The progression of the FBR is regulated by a number of biomolecules including cytokines, chemokines, and matrix metalloproteinases (MMPs). The nature of the FBR requires the spatial and temporal regulation of these mediators. MMPs are an extremely large and diverse group of enzymes that play key roles in regulating the FBR. Precise spatiotemporal regulation of MMPs defines their proteolytic activities. The aim of this project is to develop a new bioanalytical method to visualize the localization of active MMPs at …

Studies Toward The Development Of A Microelectrode Array For Detection Of Dopamine Through Redox Cycling, Anupama Aggarwal

Graduate Theses and Dissertations

Redox cycling is an electrochemical technique that cycles the reversible redox species between its oxidative states repeatedly on generator and collector electrodes. Two or more individually-addressable microelectrodes located close to each other allow redox cycling to be possible. Electrochemical behavior of a biologically important molecule, dopamine is examined under redox cycling conditions. To our knowledge, this is the first report on detection of physiological concentration of dopamine in presence of up to 100 times excess ascorbate with the use of redox cycling, without the involvement of polymer coating such as Nafion®.

Microfabrication was used to produce different geometries (parallel bands …

Dynamics And Catalytic Resolution Of Selected Chiral Organolithiums, Timothy Kum Beng

Graduate Theses and Dissertations

One of the most important developments of the last decade has been the emergence of new methods to dynamically resolve racemic organolithiums using stoichiometric amounts of the chiral ligand. When this concept is implemented successfully, it obviates the need for covalently attached chiral auxiliary based methods, asymmetric deprotonation, and asymmetric synthesis of a precursor stannane as ways to access enantioenriched organolithium compounds for use in asymmetric synthesis. Since certain electrophiles consume the chiral ligand, it is desirable to render this process catalytic in the chiral ligand.

As part of a larger study on the amenability of chiral organolithiums to a …

Preparation And Characterization Of Biomimetic Hydroxyapatite-Resorbable Polymer Composites For Hard Tissue Repair, Kristopher R. Hiebner

Department of Chemistry: Dissertations, Theses, and Student Research

Autografts are the orthopedic “gold standard” for repairing bone voids. Autografts are osteoconductive and do not elicit an immune response, but they are in short supply and require a second surgery to harvest the bone graft. Allografts are currently the most common materials used for the repair of segmental defects in hard tissue. Unlike autografts, allografts can cause an undesirable immune response and the possibility of disease transmission is a major concern. As an alternative to the above approaches, recent research efforts have focused on the use of composite materials made from hydroxyapatite (HA) and bioresorbable polymers, such as poly-L-lactide …

Influence Of Ionic Mobile Phase Additives With Low Charge Delocation On The Retention Of Ionic Analytes In Reversed Phase Hplc, Cesar Florez

Seton Hall University Dissertations and Theses (ETDs)

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Electrochemistry Of Pani/Metal Composites In Basic Solutions, Tamthinhan Quy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyaniline (PANI) has been extensively investigated due to its unique conductivity, which is primarily dependent on the oxidation state of the material and the solution pH. PANI is an insulator when it is oxidized, and the solution pH exceeds four. Numerous attempts to extend PANI's conductivity to neutral and alkaline environments have been unsuccessful. However, our previous study has demonstrated that PANI/Pd composite is conductive and catalytically active in a basic solution, pH ∼ 12. Therefore, the conductivity and the electrochemical properties of PANI composites including PANI/Au, PANI/Pd and PANI/Pt were evaluated in basic solutions. The fundamental studies of PANI/metal …

Intragroup Separation Of Trivalent Lanthanides And Actinides For Neutron Capture Experiments In Stockpile Stewardship Sciences, Narek Gharibyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Knowledge of low-energy cross sections for stable and unstable nuclei in neutron-, γ- and ion induced reactions is important in both the simulation and radiochemistry diagnosis of nuclear device performance. This dissertation explores extraction chromatography and ion chromatography methods for the intragroup separation of trivalent actinides and lanthanides in support of cross section measurements for isotopes of interest. For trivalent actinides, americium (Am(III)) and curium (Cm(III)), separation is necessary to assist in experiments related to the measurement of neutron capture cross section for ²⁴¹ Am and the production of ^{242 m} Am/^242g Am isomeric ratio. Extraction chromatography resins …

Dynamic Modeling And Characteristic Analysis Of Proton Exchange Membrane Fuel Cell, Qiu-Hong Jia, Ming Han, Bin Deng, Cai-Zhi Zhang

Journal of Electrochemistry

In this paper, a dynamic model of PEMFC is developed to estimate the dynamic performance of PEMFC by analyzing in detail the influence factors of voltage of PEMFC including various losses. The partial pressure of hydrogen and oxygen is obtained using the differential form of the ideal-gas equation in this model. The steady-state model is obtained by setting reasonable parameter values. The simulation results and experimental results have good consistency, which shows that the simulation model is correct, reasonable and effective. It analyzed the dynamic response characteristics of the output voltage and the partial pressure of hydrogen in condition of …

Preparation And Characterization Of A Composite Of Gold Nanoparticles And Single-Walled Carbon Nanotubes And Its Potential For Heterogeneous Catalysis, Anne Shanahan, James Sullivan, Mary Mcnamara, Hugh Byrne

Articles

A single-walled carbon nanotube-supported gold nanoparticle composite was prepared and characterized by X-ray diffraction, scanning transmission electron microscopy/scanning electron microscopy/transmission electron microscopy, energy-dispersive X-ray analysis, atomic absorption spectroscopy, nitrogen adsorption, Raman spectroscopy, and ultraviolet-visible spectroscopy. The Au particles were found to be crystalline, with a well-defined and narrow particle-size distribution, centered around 7 nm. The activity and selectivity of the composite for solventless aerobic oxidation of a secondary alcohol were examined, and a conversion efficiency of 95% was obtained.

An Lcms Based Assay For Detection And Quantification Of Bacterial Cell Wall Intermediates, Chandra Sekhar Arigapudi

All Capstone Projects

The main objective of my project is to determine the bacterial cell wall intermediates in E.coli and develop an LCMS method that Phosphomycin is a PEP analogue that irreversibly inhibits UDP-GluNAc-enolpyruvate transferase (MurA enzyme), which prevents the formation of N-acetyl muramic acid, which is an essential element in the Peptidoglycan cell wall. Antibacterial agents have a tremendous impact on human health. Most of the antibacterial agents, including beta lactams target the bacterial cell wall biosynthesis.The pathway for Escherichia coli is shown in page 19. Among the most widely used antibiotics, beta lactams inhibit the penicillin binding protein (PBPs)which block the …

Evaluation And In Vitro Studies Of Folate Peg Biotin And Other Peg Agents, Vikram Reddy Kasarala

All Capstone Projects

Folate is an essential component for cell growth and cell division, playing a major role in DNA synthesis. It is common sense that the rapidly dividing cells synthesize more DNA, including cancer cells. Also, it was reported that cancer cells over express Folate receptors and this was the basis for our probe for cancer cells. We used long PEG biotin in conjugation with Folate. Previous studies in our group showed that the PEG could be used in the sensor to detect and capture cancer cells. The present study was aimed at evaluating the effect of Long PEG containing Folate based …

Evaluation And In Vitro Studies Of Folate Peg Biotin And Other Peg Agents, Christopher E. Zmudka

All Capstone Projects

Folate receptor alpha is a membrane-bound protein displaying high affinity for folic acid. This receptor is believed to serve as a receptor-mediated transport system of folic acid into cancer and cells associated with inflammation. Interesting, most normal cells in the body have little if no high affinity folate receptor alpha. Based on these attributes, folate based drug delivery, imaging systems, and diagnostic systems are in several stages of development worldwide.

Numerous methods have been explored in the literature in an attempt to detect low levels of free folate receptor and/or rare circulating cancer cells. In an attempt to further exploit …

Nanoparticles For Mercury Abatement, Sunil Krishna Thanikanti

All Capstone Projects

Mercury is considered to be a global contaminant. It does not break down in the environment and can build up in living organisms. Mercury can be carried long distances on wind currents, staying in the atmosphere for long periods of time, when in its vapor form. High mercury exposure results in permanent nervous system and kidney damage. Mercury exists in three different chemical forms: elemental, inorganic, and organic. The routes of exposure can be inhalation, ingestion, or skin contact. Vapor from liquid elemental mercury and methyl mercury are more easily absorbed than inorganic mercury salts and can, therefore, cause more …

Wound Healing And The Role Of Biomarkers And Biofilms, Mujtaba Khan

All Capstone Projects

An injury to the skin alters the integrity of underlying tissues and microcirculation and thus certainly culminates in a wound. Wound healing is a highly complex, dynamic, interactive and well regulated physiological process involving blood cells, extracellular matrix, parenchyma cells and soluble mediators. It starts with alteration in integrity of tissues and ends with the formation of scar. The process of wound healing is distinguished into Haemostasis, Inflammation, Proliferation and Remodeling. Various cells like platelets, neutrophils, macrophages, lymphocytes, angiocytes, keratinocytes, fibroblasts and factors like platelet derived growth factor, transforming growth factor, platelet derived epidermal growth factors, fibroblasts growth factor, albumin, …

Analytical Evaluation Of Imaging Agents, Vineela Chowdary Talluri

All Capstone Projects

The folate receptor has achieved great importance for use in targeted drug delivery and in vitro and in vivo diagnostic assays. The folate receptor (FR) is over expressed on several cancer cell types and activated macrophages, but exists in relatively low abundance on the surface of non-cancerous tissue and non inflammatory cells. This unique attribute is the hallmark of folate – targeted methodologies allowing the diagnostic agent and/or drug to be ferried to the specific disease sites while preventing “off target” effects in normal tissues. Although several folate-based dyes have been reported, simple and detailed synthetic and purification methods for …

Capture And Analysis Of Cells Using Magnetic Beads, Alexandro Dominguez

All Capstone Projects

Magnetic separation of cells and bacterium is a fascinating field of study. There are tremendous capabilities in separation, selectivity, and sensitivity. Magnetic separation reduces complex techniques, time consuming preparation, and complicated multistep methods of separation.The separation of cells, bacterium, and macromolecules can be extremely challenging. Fortunately, magnetically tagged cells, bacterium and macromolecules can be easily separated without great expertise. Antibody magnetic micro beads are specific to a cell, bacterium, or macromolecules. Separating a mixture can lead to a better, more accurate analysis of samples that can be crucial in the medical field, therapeutic drug delivery systems, and in some circumstances …

Effects Of Weathering On Aromatic Compounds In Beach Tars From The Deepwater Horizon Disaster, Gulf Of Mexico Coast, Usa, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Operators aboard the Deepwater Horizon drilling platform lost control of the Macondo No. 1 well about 90 km southwest of the Louisiana coast on April 20, 2010, leading to a catastrophic release of ca. 550 Gg of crude oil over the next 86 days [1]. Oil from the spill soon found its way to nearby coastal areas, leaving tarry deposits on beaches and marshes. Oil was reported on the beach at Gulf Shores, Alabama (180 km northeast of the well) on June 5 and the relatively fresh sample discussed herein (GSA) was collected that same day. Oil reached the beach …

The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: Assessing Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments, Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

In studies of the organic matter (OM) fraction of marine, estuarine, fluvial, or lacustrine sediments, one of the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples [1]. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117, respectively). Major pyrolysis …

Electrochemical Analysis Based On Molecular Recognition Of Nucleic Acids And Its Applications, Dian-Ming Zhou, Jian-Hui Jiang, Guo-Li Shen, Ru-Qin Yu

Journal of Electrochemistry

Nucleic acid as the carrier of genetic information and the functional molecules for molecular biology and bioanalytical chemistry has attracted increasing interest in electrochemical analysis. This review presents a brief outline of some electrochemical analytical assays based on molecular recognition of nucleic acids. Most of these methods are focused on the detection of nucleic acid sequence, genetic mutation and nucleic acids as functional molecules.