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Full-Text Articles in Physical Sciences and Mathematics

Fluorescence Probes For Cellular Thiol And Disulfide Detection: Sythesis And Biophysical Characterization, Timothy Jonhera Oct 2011

Fluorescence Probes For Cellular Thiol And Disulfide Detection: Sythesis And Biophysical Characterization, Timothy Jonhera

Dissertations (1934 -)

The total concentration of cellular thiols is about 30 mM, and use of current fluorescent chemical probes to quantitate these thiols inside cells is impractical. We recently reported fluorescent dithio probes (donor-S-S-acceptor, DSSA) with unusually low reduction potential (- 0.6 V) that can detect changes in intracellular thiols and cross membranes of bacterial and mammalian cells, but they could not quantify thiol redox state. Here we report a new variant of the DSSA series, which has hydroxy coumarin (Ex: 320 nm, Em: 460 nm) as donor and fluorescein (Ex: 485 nm, Em: 520 nm) as acceptor. The probe was characterized …


Development, Kinetic Analysis And Applications Of 2-D Nanostructured Layered Metal Hydroxides, Stephen Majoni Oct 2011

Development, Kinetic Analysis And Applications Of 2-D Nanostructured Layered Metal Hydroxides, Stephen Majoni

Dissertations (1934 -)

Nanodimensional layered metal hydroxides which include layered hydroxy salts (LHSs) and hydroxy double salts (HDSs) have the ability to accommodate species between the layers. The structural composition of these materials can be tuned so as to create materials with targeted physico-chemical properties for applications where it is advantageous to intercalate or release molecules. Some of the applications include ion-exchange, fire retardation, catalysis, and controlled release delivery. Anion exchange reactions are among methods used to optimize these materials for targeted applications, making the characterization of exchange kinetics of practical interest. In addition, understanding fundamental factors that control retention and release of …


Mathematical Modeling And Dynamical Analysis Of The Operation Of The Hypothalamus - Pituitary - Thyroid (Hpt) Axis In Autoimmune (Hashimoto's) Thyroiditis, Balamurugan Pandiyan Jul 2011

Mathematical Modeling And Dynamical Analysis Of The Operation Of The Hypothalamus - Pituitary - Thyroid (Hpt) Axis In Autoimmune (Hashimoto's) Thyroiditis, Balamurugan Pandiyan

Dissertations (1934 -)

This thesis is a mathematical modeling study of the operation of the negative feedback control through the hypothalamus-pituitary- thyroid (HPT) axis in autoimmune (Hashimoto's) thyroiditis. Negative feedback control through the HPT axis is a mechanism in which the high levels of thyroid hormone; free thyroxine (FT4) in the blood inhibits the secretion of the pituitary hormone, thyroid stimulating hormone (TSH) into the blood. Similarly, the low levels of free thyroxine (FT4) sensed by the pituitary gland and then it secretes thyroid stimulating hormone (TSH) into the blood. Autoimmune (Hashimoto's) thyroiditis is a disease in which the immune system turns against …


Development And Applications Of Ionic Liquids And Near-Infrared Multispectral Imaging Techniques, Irena Mejac Jul 2011

Development And Applications Of Ionic Liquids And Near-Infrared Multispectral Imaging Techniques, Irena Mejac

Dissertations (1934 -)

In this work, we explore novel analytical applications of Ionic Liquids and Near-infrared multispectral imaging microscopy.

Ionic liquids (ILs) belong to a group of organic salts that are liquid at room temperature and can be, due to their unique chemical and physical properties, successfully used for a variety of applications. The main goal of this study was to explore the synergistic use of ILs in chemical separations. Specifically, chiral ILs were used as novel chiral selectors for Capillary Electrophoresis and as solvents for stationary phase in Gas Chromatography. As chiral selectors IL provides baseline-separation as well as enantiomeric separation of …


Generation Of Diverse Molecular Complexity From Simple Hydrocarbons, Anobick Sar Jul 2011

Generation Of Diverse Molecular Complexity From Simple Hydrocarbons, Anobick Sar

Dissertations (1934 -)

In an effort to make diverse molecular complexity from simple hydrocarbons, tricarbonyl(cyclohexadienyl)iron(+1) cation was prepared in two steps from 1, 3-cycloxehadiene. Reactivity of the symmetric iron cation with heteroatom nucleophiles and stabilized carbon nucleophiles was studied. Nucleophilic attack of potassium phthalimide at the dienyl terminus of the cation followed by oxidative decomplexation with Ce4+ provided the ligand N-(2,4-cyclohexadiene-1-yl)phthalimide. A series of stereochemically diverse polyhydroxyl aminocyclohexane "aminocyclitols" derivatives and a number of racemic and optically active hydroxy-and polyhydroxy 1,3-diaminocyclohexane derivatives have been synthesized from N-(2,4-cyclohexadiene-1-yl)phthalimide. The relative stereochemistries of the compounds ware assigned on the basis of the 1H NMR data …


Spectroelectrochemistry And Voltammetry Of Metalloporphinones, Florentina Tutunea Jul 2011

Spectroelectrochemistry And Voltammetry Of Metalloporphinones, Florentina Tutunea

Dissertations (1934 -)

Metalloporphinones have been found in a number of enzymes involved in nitrogen metabolism. The emphasis of this research project has been to develop spectroscopic markers in order to identify metal versus porphinone reduction. The carbonyl group in the porphinone has a very strong signal which is quite sensitive to the extent of reduction of the porphinone macrocycle.

The spectral change makes IR an important tool in the process of structure determination of metalloporphyrins because the carbonyl group shift can be correlated with the metal oxidation state. It was observed from previously published studies that a higher metal oxidation state moves …


Synthetic And Mechanistic Studies Of Coupling Reactions Involving C-H Bond Activation, Ki Hyeok Kwon Jul 2011

Synthetic And Mechanistic Studies Of Coupling Reactions Involving C-H Bond Activation, Ki Hyeok Kwon

Dissertations (1934 -)

Transition metal-catalyzed C-C bond forming reactions involving C-H bond activation have been shown to be effective methods for functionalization of unreactive compounds. Since Murai's pioneering work on ruthenium-catalyzed regioselective arene-to-alkene coupling reactions, a number of well-defined, late transition metal catalysts have been shown to mediate regioseletive C-C bond forming reaction involving C-H bond activation. Recently, late transition metal complexes have also been found to catalyze the regioselective coupling reaction of nitrogen containing compounds with alkenes as well as sp3 bond insertions and oxidative coupling reaction of aimdes. The catalytic C-C bond forming reaction involving C-H bond activation would provide simple …


Synthetic And Mechanistic Studies On The Cross-Coupling Reactions Catalyzed By Ruthenium Complexes, Ruili Gao Apr 2011

Synthetic And Mechanistic Studies On The Cross-Coupling Reactions Catalyzed By Ruthenium Complexes, Ruili Gao

Dissertations (1934 -)

Transition metal catalyzed C-H bond activation reaction is a powerful synthetic method for forming functionalized products directly from unreactive hydrocarbons, and has enormous synthetic potentials for developing chemical processes ranging from petroleum products to pharmaceutical agents. In an attempt to mimic the high stereo selectivity and region selectivity of catalytic reactions by transition metal catalysts, recent research has focused on design and synthesis of transition metal complex and the application on the coupling reactions involving C-H bond activation.

Herein, we wish to report the highly effective coupling reactions involving C-H bond activation by using well-defined ruthenium catalysts. Ruthenium hydride complex …