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25,367 full-text articles. Page 663 of 677.

I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra 2010 Wayne State University

I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra

Wayne State University Dissertations

Microwave-influenced diversity-oriented synthesis of biologically relevant small and natural-product-like molecules via multicomponent coupling reactions (MCCRs) have been investigated. Cheap, readily available starting materials in conjunction of microwave irradiation and employment of environmentally benign solvent (e.g. water) provided a common platform that allowed to access a wide array of structurally and skeletally diverse molecules. The investigation allowed us to establish a new paradigm of diversity-activity relationships (DARs) by tuning reacting components of the MCCRs and proved that in contrary to the conventional use of microwave as a rate accelerating tool, it can be used to influence reactivity of molecules. The ...


Experimental Determination Of The Weiss Temperature Of Mn12-Ac And Mn12-Ac-Meoh, Christos Lampropoulos, Shiqi Li, Lin Bo, Bo Wen, M P. Sarachik, P Subedi, A D. Kent, Y Yeshurun, A J. Millis, S Mukherjee, G Christou 2010 University of North Florida

Experimental Determination Of The Weiss Temperature Of Mn12-Ac And Mn12-Ac-Meoh, Christos Lampropoulos, Shiqi Li, Lin Bo, Bo Wen, M P. Sarachik, P Subedi, A D. Kent, Y Yeshurun, A J. Millis, S Mukherjee, G Christou

Chemistry Faculty Publications

We report measurements of the susceptibility in the temperature range from 3.5 to 6.0 K of a series of Mn12-ac and Mn12-ac-MeOH samples in the shape of rectangular prisms of length lc and square cross section of side la. The susceptibility obeys a Curie-Weiss law, χ=C/(T−θ), where θ varies systematically with sample aspect ratio. Using published demagnetization factors, we obtain θ for an infinitely long sample corresponding to intrinsic ordering temperatures Tc≈0.85 K and ≈0.74 K for Mn12-ac and Mn12-ac-MeOH, respectively ...


Thermal And Electrochemical Characterization Of Cathode Materials For High Temperature Lithium-Ion Batteries In Ionic Liquids, Jodie R. Shoaf 2010 Wright State University

Thermal And Electrochemical Characterization Of Cathode Materials For High Temperature Lithium-Ion Batteries In Ionic Liquids, Jodie R. Shoaf

Browse all Theses and Dissertations

Finding a cathode material to operate a high-temperature Li-ion battery in the presence of an ionic liquid has become an attractive area of research. Three cathode materials, LiCoO2, Li4Ti5O12, and LiFePO4, were received from Electrochemical Systems Inc. of Knoxville, TN. Three ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was either ethyl, pentyl or hexyl, and contained a bis(pentafluoroethylsulfonyl)imide (Beti-) anion. The thermal and electrochemical properties of each ionic liquid, of each cathode material, and each combination of cathode material in the presence of ionic liquid were studied. All of the ionic liquids ...


Functionalized, Semicrystalline Poly(Ether Ketone)S Via In Situ Modification Chemistry, Raghavendhar Reddy Kotha 2010 Wright State University

Functionalized, Semicrystalline Poly(Ether Ketone)S Via In Situ Modification Chemistry, Raghavendhar Reddy Kotha

Browse all Theses and Dissertations

AB3 monomer (3,4,5-Trifluoro-4'-hydroxybenzophenone) was used for polymerizations in order to mimic the combination of AB and AB2 monomers, and which has potential to facilitate concurrent polymerization and functionalization. 'Pre' and 'post' polymerization functionalization of the PEK system was done using phenol, 4-bromophenol, and 3/4-aminophenol. The solubility of the functionalized polymers was increased; and the crystallinity was decreased significantly compared to the corresponding unfunctionalized homopolymer. The polymers were characterized by 1H and 13C NMR spectroscopy, Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). DSC results showed that the crystallinity of the polymer was ...


Small Molecule Caspase Inhibitors Using Isatin And Oxindole Scaffolds And A Combinatorial Approach, Hagar Mahmoud Abdallah 2010 Wright State University

Small Molecule Caspase Inhibitors Using Isatin And Oxindole Scaffolds And A Combinatorial Approach, Hagar Mahmoud Abdallah

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Quinolyl-valyl-O-methylaspartyl-[2,6-difluorophenoxy]-methyl ketone (Q-VD-OPh) is a next generation broad spectrum caspase inhibitor, the effectiveness and reduced toxicity of which can be partially attributable to the carboxyterminal O-phenoxy group as well as the amino terminal quinolyl groups. We seek to incorporate some of these unique recognition elements onto small molecule derived protease inhibitors with drug like properties. Specifically, heterocyclic scaffolds such as isatins and oxindoles. Thus, isatins bearing electron withdrawing groups on C-5 and 2,6-difluorobenzyl moieties have been prepared by analogy to the well studied N-substituted 5-pyrrololidinylsulfonyl isatins. Moreover, 3-benzylidene oxindole derivatives bearing these structural motifs have also ...


Novel Synthesis Of Polyhydrogenated Fullerenes, Angela Campo 2010 Wright State University

Novel Synthesis Of Polyhydrogenated Fullerenes, Angela Campo

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Hydrogenated fullerenes are of interest as a starting material in metal fulleride synthesis. By reacting C60H2 with various metals, alloyed metal fullerides could be produced. To achieve this goal, first a reliable synthesis of C60H2 must be determined. C60H2 is difficult to synthesis exclusively; C60H4 and C60H6 are also produced. Reduction of C60 with NaBH4 produced a mixture of products as well as excessive unreacted C60. Attempts to modify this reaction to achieve C60H2 exclusively were unsuccessful. A novel ...


Temperature And Ph Responsive Polyethylenimine Systems As Potential Nonviral Gene Vectors, S. Chad Skidmore 2010 Wright State University

Temperature And Ph Responsive Polyethylenimine Systems As Potential Nonviral Gene Vectors, S. Chad Skidmore

Browse all Theses and Dissertations

Modified HPEI was used to determine if the LCST could be controlled by varying multiple variables, including: percent modification, pH, salt solution concentration, and weight percent. Two modifications were done with butylene oxide (Butox) and isobutyryl amide (IBAm). Specifically, 100% (HPEI-Butox1.00)butoxylated and 10% (HPEI-IBAm0.10), 54% (HPEI-IBAm0.54), and 70% (HPEI-IBAm0.70) amidated samples were synthesized. Additionally, HPEI-IBAm0.54 was further modified with hydroxyl ethyl groups (HPEI-IBAm0.54 Eox0.46) and ethyl groups (HPEI-IBAm0.54-Et0.44). The LCSTs of all amidated systems were below body temperature, 37 °C, at pH = 7.4. This indicates an ability of these ...


Stability Of Spore-Based Sensing Systems, Abhishek Sangal 2010 University of Kentucky

Stability Of Spore-Based Sensing Systems, Abhishek Sangal

University of Kentucky Master's Theses

The full exploitation of bacterial whole-cell biosensing systems in field applications requires the survival of bacterial cells and long term-preservation of their sensing ability during transportation and on-site storage of such analytical systems. Specifically, there is a need for rapid, simple and inexpensive biosensing systems for monitoring human health and the environment in remote areas which often suffer from harsh atmospheric conditions and inadequate commercial distribution and storage facilities. Our laboratory has previously reported the successful use of bacterial spores as vehicles for the long-term preservation and storage of whole-cell biosensing systems at room temperature.

In the present research, we ...


A Comparison Of Atmospheric Pahs In Pine Needles And High-Volume Sampler Filters In The Dayton Metro Area, Timothy A. Tomashuk 2010 Wright State University

A Comparison Of Atmospheric Pahs In Pine Needles And High-Volume Sampler Filters In The Dayton Metro Area, Timothy A. Tomashuk

Browse all Theses and Dissertations

Samples of filters from High-volume (HiVol) samplers of particulate matter (PM) with a size of 10 micrometers or less were deployed for five months in Moraine and Yellow Springs, OH, by the Regional Air Protection Control Agency and analyzed for the Environmental Pollution Agency (EPA) 16 polycyclic aromatic hydrocarbons (PAHs). Pine needles on trees near the HiVol samplers were also collected and analyzed for a comparison with the active samplers to estimate atmospheric PAH concentrations. Pine needles were found to collect lower molecular weight (LMW) compounds far more than HiVol sampler and thus their profiles shown to compliment the HiVol ...


Electrochemical Deposition Of Molybdenum And Tungsten From Trinuclear Metal Clusters (M3O2(Oac)6(H2O)3(Cf3So3)2) In 1-Ethyl-3-Methylimidazolium Tetrafluoroborate Ionic, Charles Woods 2010 Wright State University

Electrochemical Deposition Of Molybdenum And Tungsten From Trinuclear Metal Clusters (M3O2(Oac)6(H2O)3(Cf3So3)2) In 1-Ethyl-3-Methylimidazolium Tetrafluoroborate Ionic, Charles Woods

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Electrochemical properties of Mo2WO2(O2CCH3)6(H2O)3(CF3SO3)2 and W3O2(O2CCH3)6(H2O)3(CF3SO3)2 clusters in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) ionic liquid was investigated. Cyclic voltammograms using a platinum electrode indicated that deposition of metal had occurred. Constant potential electrolysis of Mo2WO2(O2CCH3)6(H2O)3(CF3SO3)2 at -1.9 V using a platinum foil electrode was performed. Atomic force microscopy (AFM ...


Exploration Using Reaction Temperature To Tailor The Degree Of Order In Micro-Block Copolymer Proton Exchange Membranes, John Quentin Buquoi III 2010 Wright State University

Exploration Using Reaction Temperature To Tailor The Degree Of Order In Micro-Block Copolymer Proton Exchange Membranes, John Quentin Buquoi Iii

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The ability to control the self-assembly of sulfonated poly(arylene ether) sulfones (s-PAESs) was explored by tailoring rate coefficients, via temperature, in an A2 + B2 + B2' Nucleophilic Aromatic Substitution (SNAr) approach. The reactivity of various electrophilic sites were studied and tuned, via temperature control, to elicit a range of more ordered and disordered polymers of equivalent monomeric composition. These polymers were characterized by 1H and 13C NMR spectroscopy and found to have highly disordered polymer configuration at higher temperatures while having a more regular configuration at lower temperatures.


Towards The Total Synthesis Of Haplomyrtin, Nora Ellen Hunter 2010 Wright State University

Towards The Total Synthesis Of Haplomyrtin, Nora Ellen Hunter

Browse all Theses and Dissertations

Haplomyrtin, a 1-aryl-2,3-naphthalide lignan obtained from Turkish Haplophyllum myrtifolium and Haplophyllum telephioides offers a number of synthetic challenges with the incorporation of two aromatic hydroxyl groups at positions C4 and C7 on the naphthalene ring system and regiospecific condensation of the γ-lactone ring. Improvements towards the total synthesis of haplomyrtin were pursued with commercially available vanillin and piperonal in a total of 8 separate steps. All steps have excellent reproducibility. This strategy includes bromination of protected vanillin to yield 2-(4-(4-methoxybenzyloxy)-2-bromo-5-methoxyphenyl)-1,3-dioxolane and 2-(4-(benzyloxy)-2-bromo-5-methoxyphenyl)-1, 3-dioxolane in 48% and 88% yield respectively, and ...


Mapping The Reactivity Surface Of Metal-Olefin Reactions, Joshua Davis, Stephen A. Matchett 2010 Grand Valley State University

Mapping The Reactivity Surface Of Metal-Olefin Reactions, Joshua Davis, Stephen A. Matchett

Student Summer Scholars

Our overall goal of our project was to map susceptibility for nucleophilic attack on a series of metal-olefin compounds as a function of their geometry. The scope of this paper, however, is directed toward stabilizing our reactants in solution and the developing methods to test the reaction. In order to measure the susceptibility on the series we must know three things: the initial concentration of the nucleophile and the metal-olefin as well as a way measure the rate of reaction. In order to take these measurements, the solvent used must not interact with either reactant, must not interfere with the ...


Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene 2010 Old Dominion University

Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Background: Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase ...


Chemical Bath Deposition And Electrodeposition Of Epitaxial Semiconductor Materials For Application In Photovoltaic Devices, Guojun Mu 2010 Missouri University of Science and Technology

Chemical Bath Deposition And Electrodeposition Of Epitaxial Semiconductor Materials For Application In Photovoltaic Devices, Guojun Mu

Doctoral Dissertations

"This dissertation investigates the chemical bath deposition of zinc oxide and electrodeposition of cuprous iodide on polycrystalline and single crystal substrates. Paper I describes the chemical bath deposition and characterization of titled epitaxial zinc oxide nanospears on Si(001) single crystal substrate. In Paper II, the chemical bath deposition of zinc oxide nanospears from highly alkaline solutions is discussed in detail, including a thermodynamic calculation of saturation and speciation of Zn(II) in aqueous solution, and a kinetic study of the deposition process. In this paper the epitaxial zinc oxide is reported grown on Au(100), (110), and (111) single ...


Silver Nanoparticle Polymer Composite Based Humidity Sensor, Aoife Power, Tony Betts, John Cassidy 2010 Technological University Dublin

Silver Nanoparticle Polymer Composite Based Humidity Sensor, Aoife Power, Tony Betts, John Cassidy

Articles

Silver nanoparticles were synthesised by a chemical reduction process in order to produce an aqueous colloidal dispersion. The resulting colloids were then characterised by a combination of UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction and transmission electron microscopy and the nanoparticles were found to have an average diameter of 20–22 nm. The Ag/polymer nanocomposites were then applied to platinum interdigital electrodes as sensor coatings and the capability of the resulting sensor as a humidity detector investigated. With the application of 1 V, a current developed which was found to be directly proportional to humidity levels. The sensor gives ...


Influence Of The Reducing Agent Triphenylphosphine On Cyclooxygenase-1 Metabolism Of Arachidonic Acid, Rohini Sidhu 2010 Eastern Michigan University

Influence Of The Reducing Agent Triphenylphosphine On Cyclooxygenase-1 Metabolism Of Arachidonic Acid, Rohini Sidhu

Master's Theses and Doctoral Dissertations

Cyclooxygenase (COX) metabolizes the polyunsaturated fatty acid arachidonic acid (AA) to PGG2, a cyclic endoperoxide that also contains a hydroperoxide, which is subsequently reduced to an alcohol in the enzyme to yield PGH2. Reactions catalyzed by COX-1 are significantly influenced by lipid hydroperoxides. The tyrosyl radical that abstracts the 13 pro(s) hydrogen from AA to initiate the COX catalytic cycle is generated by iron-oxo derivatives in the enzyme that result from lipid hydroperoxide interaction with heme iron. Commercial preparations of arachidonic acid (AA) contain lipid hydroperoxides that can be separated from AA by thin layer chromatography and readily reduced ...


Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam 2010 Eastern Michigan University

Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam

Master's Theses and Doctoral Dissertations

Silver nanoparticles of varying sizes were synthesized. Their effects on enhancing or quenching the photochemical processes of tryptophan fluorescence, a ruthenium complex decay constant and chemiluminescence of luminol and ferricyanide, were studied. The tryptophan fluorescence was slightly enhanced by smaller nanoparticles and showed slight quenching in the presence of larger nanoparticles. The tris (2,2’-bipyridyl ruthenium (II) chloride) complex was excited using a 532 nm laser, and the decay constant was measured. Neither gold nor silver nanoparticles showed an impact on this process. The luminol chemiluminescence was studied with an emphasis on holding the concentration of nanoparticles, surface area ...


Analysis Of The Effect Of Various Ligands On The Hydrolysis Of Ruthenium (Iii) Complexes And Interpretation Of Kinetics Of Hydrolysis Profiles By Uv-Visible Spectrophotometry, Sudheer Koneru 2010 Eastern Michigan University

Analysis Of The Effect Of Various Ligands On The Hydrolysis Of Ruthenium (Iii) Complexes And Interpretation Of Kinetics Of Hydrolysis Profiles By Uv-Visible Spectrophotometry, Sudheer Koneru

Master's Theses and Doctoral Dissertations

Cancer is one of the major causes of death in the world. Discovery of platinum metal-based drugs like cisplatin and carboplatin have proved to be successful in cancer treatment. Due to subsequent development of resistance, side effects, and fewer toxic effects of these drugs, the usage of these drugs has been limited. Novel drugs were being synthesized utilizing the transition metals like ruthenium, osmium, and copper.

In this research, ruthenium metal complexes of the formula HL[RuCl4L2] (where L= ligand) were synthesized. These ruthenium-based drugs exist in prodrug forms which are activated into antitumor drugs by means of hydrolysis, redox ...


Characterization Of The Binders In The Rock Art Of Cueva La Conga, Nicaragua, Ran Li 2010 Eastern Michigan University

Characterization Of The Binders In The Rock Art Of Cueva La Conga, Nicaragua, Ran Li

Master's Theses and Doctoral Dissertations

Cueva La Conga is the only known painted cave in Nicaragua, in a part of that country about which little is known archaeologically. The rock art, which includes carved rock formations as well as paintings and handprints, may provide clues about the past people and culture of this area. Archaeologists want to know if the paintings were influenced by the Maya to the north, or the Caribbean cultures to the east, or were a purely indigenous development. Determining the age of the paintings will help to understand the possible cultural relationships between known cultures and the rock art of Cueva ...


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