Physical Sciences and Mathematics Commons^™

Synthesis, Characterizations, And Evaluation Of New Reactive Two-Photon Absorbing Dyes For Two-Photon Excited Fluorescence Imaging Applications, Katherine J. Hales

Electronic Theses and Dissertations

Recent, cooperative advances in chemistry, biology, computing, photophysics, optics, and microelectronics have resulted in extraordinary developments in the biological sciences, resulting in the emergence of a novel area termed 'biophotonics'. The integrative and interdisciplinary nature of biophotonics cuts across virtually all disciplines, extending the frontiers of basic cellular, molecular, and biology research through the clinical and pharmaceutical industries. This holds true for the development and application of the novel imaging modality utilizing multiphoton absorption and its extraordinary contribution to recent advances in bioimaging. Intimately involved in the revolution of nonlinear bioimaging has been the development of optical probes for probing …

Analytical And Synthetic Methods For Anatoxins., Janet Crowley

Theses

This thesis is focused on the potent cyanobacterial neurotoxins anatoxin-a (AN), its methyl analogue homoanatoxin-a (HMAN) and their non-toxic dihydro- and epoxydegradation products. In commencing the investigation into this area a literature review was performed in order to identify areas where more research and method development was required (Chapter 1). The review highlighted the fact that although a number of analytical methods had been developed for the analysis of AN, there were few methods for the determination of its potent homologue HMAN and their non-toxic degradation products. As these neurotoxins degrade quickly it is important to monitor their degradation products, …

Elucidation Of The Mass Spectral Fragmentation Pathways Of Cyclic Hepatopeptides Microcystins, Paloma Muniz Ortea

Theses

The most frequently found cyanobacterial toxins in blooms from fresh and brackish waters are the cyclic peptide microcystins (MCs) and nodularin family. These toxins cause fatal poisonings of agricultural livestock, wild animals, birds and fish on a worldwide basis. The involvement of these toxins in human health problems has also been inferred in several countries and their presence in drinking water sources is of interest to the drinking water industry.

One of the biggest problems in the analysis of MCs is the lack of commercially available standards to be used for the identification and characterisation of these cyanobacterial toxins. One …

Assessment And In Vitro Repair Of Damaged Dna Templates From Forensic Stains, Ashley Hall

Electronic Theses and Dissertations

DNA extracted from biological stains is often intractable to analysis. This may due to a number of factors including a low copy number (LCN) of starting molecules, the presence of soluble inhibitors or damaged DNA templates. Remedies may be available to the forensic scientist to deal with LCN templates and soluble inhibitors but none presently exist for damaged DNA. In fact, only recently has the biochemical nature, the extent of DNA damage in physiological stains and the point at which the damage inflicted upon a particular sample precludes the ability to obtain a genetic profile for purposes of identification been …

Combining Structure-Based Drug Design And Pharmacophores, Renate Griffith, T. T. T. Luu, James A. Garner, Paul A. Keller

Faculty of Science - Papers (Archive)

Development towards integrated computer-aided drug design methodologies is presented by utilising crystal structure complexes to produce structure-based pharmacophores. These novel pharmacophores represent the ligand features that are involved in interactions with the target protein, as well as the space around the ligand occupied by the protein. The protein-ligand complexes can also yield information about all interactions that ligands could potentially form with the binding site, as well as about the size of the binding cavity. Together, these describe a 'superligand', which can also be viewed as a pharmacophore. Various types of novel pharmacophores are discussed and compared, using HIV-1 Reverse …

Punishment And Rehabilitation Views Of Social Work Majors And Non-Social Work Students: An Exploratory Study, Eric G. Lambert, Sudershan Pasupuleti, Reva I. Allen

Journal of the South Carolina Academy of Science

No abstract provided.

Estimation Of Bound Carbonyls In Pmma-R-Ps Copolymers Adsorbed On Silica, Pavan K. Challa, Bing Zhang, Frank D. Blum

Chemistry Faculty Research & Creative Works

The adsorption of random copolymers on solid surfaces is essential for developing good properties in composite materials. A good control and understanding of interfaces allows tuning of the properties of the individual components. Interfacial polymers are important in many industrial applications such as photoresists, protective coatings, metal insulator and semi-conductor insulator junctions, metal-filled polymer composites and polymer-lined metal containers for protective food packaging. The effect of the drying process,1 configuration and tacticity,2 molecular mass, density of surface hydroxyls,3 and adsorbed amounts4 have already been studied for interfacial polymers. The thermal characterization for polystyrene,5 PMMA11 and PMMA-r- PS6 copolymers adsorbed on …

The Application Of 31p And 1h Nmr Spectroscopy To The Study Of Freeze Tolerance And Freeze Avoidance In Biological Systems, Nicholas C. Wright

Masters Theses

No abstract provided.

Separation And In Situ Catalytic Testing Of A Dirhodium Tetraphosphine Catalyst, Bobby Lloyd Barker

LSU Doctoral Dissertations

Attempts to study the asymmetric hydroformylation abilities of [rac-Rh₂(nbd)₂(et,ph-P4)](BF₄)₂ were made through the separation of the enantiomers of et,ph-P4 using a chiral HPLC column. Efforts were also made to optimize the NiCl₂ separation chemistry for the methyl analogue of et,ph-P4 for use in asymmetric hydroformylation. A study of hydroformylation of olefins using [rac-Rh₂(nbd)₂(et,ph-P4)](BF₄)₂ in ionic liquids was also performed, leading directly to the important (and unexpected) effect of increased hydrogen pressure on [rac-Rh₂(nbd)₂(et,ph-P4)](BF₄)₂ in the acetone/water system to …

Characterization Of Aged Polymer Modified Asphalt Cements For Recycling Purposes, Codrin Daranga

LSU Doctoral Dissertations

Since polymer modified asphalt cement (PMAC) has been employed for a decade, the lifetime and wear on some of these pavements is reaching a stage where resurfacing is necessary. This research focuses on the characterization of aged polymer modified asphalt cements (PMAC) to evaluate their potential for recycling. A styrene-butadiene-styrene tri-block (SBS) polymer modified asphalt cement was selected and characterized using standard asphalt binder qualification techniques, i.e., the Superpave PG protocol. We developed a procedure to characterize the relative concentration of polymer in asphalt cements by gel permeation chromatography (GPC). Infrared spectrographic, thermogravimetric and rheological techniques were used to identify …

Dielectric Properties And Maxwell-Wagner Relaxation Of Compounds Acu3ti4o12 (A=Ca,Bi2/3,Y2/3,La2/3), Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy

Physics Faculty Publications

We have studied the frequency and temperature dependences of permittivity and impedance of the compounds ACu3Ti4O12 A=Ca, Bi2/3, Y2/3, La2/3 in the ranges of 10−1–106 Hz and −150–200 °C. All compounds investigated display similar dielectric properties. Specifically, they all have a Debye-like relaxation and their dielectric constants are independent of frequency and temperature over a wide range. They all have two electrical responses in impedance formalism, indicating that there are two distinct contributions. We attribute them to grains and grain boundaries in the ceramic samples and explain the dielectric behaviors by Maxwell-Wagner relaxation arising at the interfaces between grains and …

Synthesis Of Alkylthiol-Containing Fluorene Derivatives For Gold Nanoparticle Functionalization, Sriram Mukundarajan

Electronic Theses and Dissertations

A novel synthetic methodology has been developed for attaching fluorene derivatives, containing different types of electron donating and accepting groups at the 2 and 7 positions, to gold nanoparticles of different sizes by exploiting the affinity of the thiol functional group for gold. The distance between the dye and nanoparticles was varied by introducing two alkyl chains containing different number of carbon atoms at the 9 position on the fluorene ring system. The methodology that was developed gave enough scope for performing Radiative Decay Engineering (RDE) studies, in order to investigate the impact of gold nanoparticles on the singlet oxygen …

Novel Cyanine-Amp Conjugates For Efficient 5' Rna Fluorescent Labeling By One-Step Transcription And Replacement Of [γ-32P] Atp In Rna Structural Investigation, Na Li, Changjun Yu, Faqing Huang

Faculty Publications

Two novel fluorescent cyanine-AMP conjugates, F550/570 and F650/670, have been synthesized to serve as transcription initiators under the T7 φ2.5 promoter. Efficient fluorophore labeling of 5′ RNA is achieved in a single transcription step by including F550/570 and F650/670 in the transcription solution. The current work makes fluorescently labeled RNA readily available for broad applications in biochemistry, molecular biology, structural biology and biomedicine. In particular, site-specifically fluorophore-labeled large RNAs prepared by the current method may be used to investigate RNA structure, folding and mechanism by various fluorescence techniques. In addition, F550/570 and F650/670 may replace [γ-³²P]ATP to prepare …

Determination Of Trifluoroacetate By Ion Chromatography For Snow And Ice Analysis, Jon Hanson

The Journal of Undergraduate Research

Trifluoroacetic acid (TEA) is a product of the atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). HCFCs and HFCs are widely used substitutes for chlorofluorocarbons (CFCs) that have been found to contribute to the loss of stratospheric ozone. Deposits of TEA with precipitation (rain and snow) can lead to its presence and accumulation in the aquatic and cryosphere environments, with unknown long-term environmental consequences. Investigation on TEA impact and its fate in the environment requires sensitive, accurate, and fast analytical methods. The determination of trace concentrations of TEA using the technique of ion chromatography (IC) is investigated in this study, …

Electronic To Vibrational Energy Transfer From Cl* (3 2P1/2) To N2O(Ν1): Failure Of A Simple Kinetic Mechanism, Brian Brumfield

Browse all Theses and Dissertations

Experimental kinetic studies were carried out examining the electronic to vibrational (E-V) energy transfer from spin-orbit excited Cl*(3 ²P_1/2 , 882 cm^-1) to N₂O(ν₁) (symmetric stretch 1285 cm^-1). All studies were carried out in the gas phase at room temperature (298 ± 2 K). Cl* was generated by pulsed laser photolysis of ICl at 532 nm in the presence of various mixtures of N₂O, ICl,Ar, and SO₂. Time-resolved IR signals of N₂O(ν₁) fluorescence at 7.8 μm were analyzed to obtain rate coefficients …

A General Synthesis Of Tris-Indole Derivatives As Potential Iron Chelators, R. Bryan Sears, Russell A. Carpenter, Christine R. Whitlock

Department of Chemistry and Biochemistry Faculty Publications

The development of a novel route for the synthesis of a new class of compounds is described. The first tripodal, tris-indole amines are prepared by straightforward routes.

Computational Study Of A Novel Dinuclear Metal Complex, Dragos Seghete

Inquiry: The University of Arkansas Undergraduate Research Journal

The first compound containing an M-H-M was recently reported by Vicic et al. With recent availability of large computational resources, molecular modeling has become a reliable tool for confirming experimental results. The novel dinuclear Ni complex [( dippm)2Ni2Br2]( 0 -H) was investigated in this work from a theoretical perspective. Full geometry optimization was carried on the dinuclear Ni complex at the DFT/B3LYP with the 6-31G* basis set. The result verifies the linear Ni-H-Ni bond. Two different starting structures that converged to the same geometry confirm that a global minimum was reached. The computed structure differs from the experimentally determined one …

Investigation Of Iron (Iii) Desferrioxamine B Oxalate Ligand Exchange By Uv-Vis Spectroscopy: The Next Step In Developing A Quantitative Analytical Method For Measuring Bioavailable Iron In Marine Ecosystems, Ken L. Pitter

Honors Theses

To date there are no analytical techniques designed to exclusively measure bioavailable iron in marine environments. The goal of this research is to develop such a technique by isolating the bioavailable iron using the terrestrial siderophore desferrioxamine B (DFB). This project contained many challenging aspects, but the specific goal of this study was to develop a robust analytical technique for quantification of Fe(III)-DFB complexes at nanomolar concentrations. Past work showed that oxalate (Ox) promotes photodissociation of Fe(III)-DFB to Fe(Il), and we are specifically interested in the mechanism of this process. A model was developed using known thermodynamic constants for Fe(III)-DFB …

An Analysis Of The Effect Of Carbon Dioxide On The Decay Rates Of Superoxide, Michael Jay Walsh

Honors Theses

The radical dioxygen anion, superoxide has been shown to react with carbon dioxide in nonprotic and aqueous systems. Indirect evidence suggests that superoxide also reacts with carbon dioxide and carbonate species dissolved in water. This study involved conducting experiments to determine the decay rate of superoxide in the presence of carbon dioxide and carbonate species. Experiments were conducted by sparging an alkaline bicarbonate buffer with carbon dioxide and measuring the decay rate of superoxide added to the solution. Although the specific reaction mechanism and rates have not been determined first order superoxide decay rates as high as 3.8x10-2s-1 were obtained …

The Synthesis And Characterization Of Bicyclooxacalixarenes, Kevin J. Selby

Honors Theses

Bicyclooxacalixarenes were synthesized in high yield via a selective, room temperature Sn Ar reaction of phluoroglucinol with 2,6-dichloropyridines. Functionality on the 2,6-dichloropyridioe was varied by changing the electron-withdrawing groups in the 3 and 5 positions (using chlorine, nitro groups, and cyano groups) and the side-chains in the 4-position (using ethyl, butyl, phenyl and ρ-tolyl groups). The resulting cage-like molecules were studied by X-ray crystallography and tested for metal complexation.

Analytical Tools For Studying Phosphorus And Nitrogen Lake Nutrient Dynamics And Their Application To The Field, Ivan Mihajlov

Honors Theses

In order to evaluate the causes and conditions that lead to cyanobacteria blooms in northern temperate lakes, studies of nutrients such as total phosphorus, total nitrogen, phosphate, and nitrate are necessary. Sensitive, environmentally friendly and cost-effective techniques were developed to detect ppb-level nitrates and phosphates in the lake water. Phosphate was analyzed by luminol chemiluminescence, while the quantification of nitrate was performed by capillary electrophoresis (CE) using indirect UV detection, with a background electrolyte consisting of pyromellitic acid, hexamethonium hydroxide and triethanolamine. Sample injection methods for the CE were optimized for the analysis in Belgrade Lakes, Maine. Vertical profiles of …

Exploring Marine Biotoxins Using Analytical Techniques Based On Mass Spectrometry, Mónica Fernández Amandi

Theses

The impact of phycotoxins on human and animal health is of important concern for worldwide authorities and the scientific community. Domoic acid (DA) is a neurotoxin produced by phytoplankton {Pseudonitzchia spp.). It enters the food chain through the consumption of shellfish that feed on toxic diatoms. DA has been responsible for several outbreaks affecting humans and animals all around the world. Yessotoxin (YTX) is produced by dinoflagellate species {Protoceratiuni reticulatum) which are globally distributed. Its toxicity is low when ingested orally. However, the co-extraction of YTX with diarrhetic shellfish poisoning (DSP) toxins, derives false positives when the mouse bioassay is …

Chemical And Biochemical Modification Of Surfaces For Control Of Wettability, Adsorption, And Drug Delivery, Susan C. D'Andrea

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis Of Cyclopropanes Via Organoiron Methodology: Preparation Of The C9–C16 Alkenylcyclopropane Segment Of Ambruticin, Julie Lukesh, William Donaldson

Chemistry Faculty Research and Publications

A synthesis of the C9–C16 segment of ambruticin is described which relies on organoiron methodology to establish the 1,2,3-trisubstituted cyclopropane ring.

Methyl Methacrylate Oligomerically-Modified Clay And Its Poly (Methyl Methacrylate) Nanocomposites, Xiaoxia Zheng, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

A methyl methacrylate oligomerically-modified clay was used to prepare poly(methyl methacrylate) clay nanocomposites by melt blending and the effect of the clay loading level on the modified clay and corresponding nanocomposite was studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed intercalated/delaminated morphology with good nanodispersion. The compatibility between the methylacrylate-subsituted clay and poly(methyl methacrylate) (PMMA) are greatly improved compared to other oligomerically-modified clays.

Comparative Study Of Structural Properties Of Yba2cu3o7 Thin Films On Srtio3 Single Crystal And Bicrystal Substrates By X- Ray Diffraction, M. Navacerrada, A. Mehta, H. Sahibudeen, Juana Acrivos

Faculty Publications, Chemistry

We present a comparative study in terms of structural properties deduced from X - ray diffraction diagrams between YBa2Cu3O7 (YBCO) thin films fabricated on SrTiO3 (STO) single crystal substrates and bicrystallines substrates with a symmetrical tilt angle of 24 degrees. Periodic Lattice Distortions (PLD) have been observed around different Bragg peaks in YBCO thin films deposited on STO bicrystals while only diffraction peaks have been measured in the diagrams corresponding to the YBCO thin films deposited on STO single crystal substrates. Only in regions situated a 3.5 mm at both sides of the grain boundary the PDL have been investigated. …

Yba2cu3o7 Electro-Magneto-Optic Effects In Ba L2,3 X-Ray Absorption Near Tc, Juana Vivó Acrivos

Juana Vivó Acrivos

The onset of electro magneto-optic effects, observed at the Ba L2,3 edges synchrotron X-ray absorption by a YBa2Cu3O7 single crystal, 10 K above the transition temperature to superconductivity, Tc ~ 92 K is used to identify the role played by the Ba donor layer in the transition to superconductivity in the CuO2 layers. Negative permeability leads to Faraday rotation of the transmitted beam below T = 112 to 56 K for the 22 μm thick single crystal (c-axis orientation of 8π/18 relative to εX-rays) and sharp changes in the density of empty final states lead to zero transmitted radiation in …

Bismuth Triflate Catalyzed Friedel-Crafts Acylations Of Sydnones, Jennifer Ann Fisher

Browse all Theses and Dissertations

In the present work, suitably functionalized arylsydnones were used to synthesize a variety of 4-acylsydnones and diacyl sydnones, both as potential precursors to novel sydnoquinolines.The approach to the diacyl species is based on the discovery that activated sydnonesbrominate in both the 4 position of the sydnone ring and on the phenyl ring. Thus, it seemed likely that Friedel-Crafts reactions on an activated sydnone would give diacylated species for McMurray coupling to sydnoquinolines. Friedel-Crafts acylations on the 4 position of the sydnone ring have been achieved in high yields using 4 equivalents of various alkyl anhydrides, 25 mol % of bismuth …

The Determination Of Environmentally Important Metals In Marine Sediments, Linda Tyrrell

Masters

Surface sediment samples were collected at sites within the Rockall Through at water depth ranges from 700 – 2774 metres. The study area was predefined by the availability of samples. Samples were collected by the British Geological Survey during their gravity core survey undertaken in 1998. Methods were optimised and validated for lead, cadmium, chromium, copper, nickel, zinc, lithium and aluminium using atomic absorption spectroscopy following total digestion, and for mercury, using cold vapour atomic fluorescence spectroscopy following partial digestion. The measured metal concentration were normalised to Li to compensate for the influence of natural variability in the concentration of …

The Discovery-Oriented Approach To Organic Chemistry. 6. Selective Reduction In Organic Chemistry: Reduction Of Aldehydes In The Presence Of Esters Using Sodium Borohydride, Ram Mohan, Ashvin Baru

Scholarship

Chemoselective reductions are valuable in organic synthesis and are routinely discussed in a sophomore organic chemistry course. Yet, there are few examples of laboratory experiments that illustrate such chemoselectivity. A reaction that is routinely discussed in sophomore organic chemistry is the selective reduction of aldehydes and ketones using sodium borohydride. Esters are typically not affected by NaBH4. However, none of the lab experiments reported to date illustrate this chemoselectivity (1). We have developed a discovery-oriented lab experiment that illustrates the chemoselective nature of reductions using sodium borohydride. The experiments involve the reduction of vanillin acetate (Scheme I) and methyl 4-formylbenzoate …