Browsing Chemistry & Biochemistry by Issue Date
Now showing items 21-40 of 553
-
METHODS FOR STEREOSELECTIVE SYNTHESIS OF GLYCOPYRANOSYLAMIDE LINKAGE
(2004-02-20)Glycoproteins play an important role in biological processes including intercellular communication, cell-cell recognition, and cell growth regulation. The study of cellular processes is often limited by the availability ... -
Location specific recognition of the recombination hot-spot "Chi" by the E. coli RecBCD enzyme
(2004-04-06)RecBCD is an ATP-dependent helicase and exonuclease, which generates 3'-single-stranded DNA (ssDNA) ends used by RecA for homologous recombination. Critical to this function is its encounter with an regulatory DNA octamer ... -
Spatially Heterogeneous Dynamics and String-Like Correlated Motion in Supercooled Liquids and Polymers
(2004-04-16)Dense liquids above their glass transition exhibit spatially heterogeneous dynamics (SHD) in which regions within the liquid exhibit enhanced or diminished mobility relative to the average on some time scale. The spatially ... -
Hypercoordinate Silicon Compounds In Organic Synthesis: Improved Methods For The Synthesis Of Aryl(Trialkoxy)Silane Derivatives; And Trimethylsilyl Cyanide As A Cyanide Source For Nucleophilic Substitution
(2004-04-26)Palladium-catalyzed cross-coupling reactions are versatile methods for the synthesis of carbon-carbon bonds. The Stille and Suzuki cross-coupling protocols have achieved prominence in the synthesis of pharmaceuticals and ... -
Investigations of Solvent Polarity at Liquid/Liquid Interfaces by SHG Spectroscopy Using Molecular Rulers
(2004-04-28)Homologous series of solvatochromic surfactants have been synthesized to study polarity at liquid/liquid interfaces. Each surfactant series consists of hydrophobic, para-nitroanisole-based chromophores attached to ionic ... -
Study of Wet-Chemically-Prepared Hydrogen-Terminated Silicon (111) Surfaces and a Novel Implementation of a High-Resolution Interferometer
(2004-04-30)This thesis summarizes my graduate study under the National Institute of Standards and Technology (NIST) Atom-Based Dimensional Metrology Project, in which we are developing methods for measuring sub-micrometer dimensions ... -
Application of Silicon-Based Cross-Coupling Technology to Aryl Triflates
(2004-05-06)The goal of this research was to explore the use of aryl silatranes as a replacement for aryl siloxanes in the palladium-catalyzed cross-coupling reaction with aryl triflates. Phenylsilatrane underwent fluoride-induced ... -
Ethylene Polymerization Using a Zirconium Amidinate Supported Catalyst
(2004-05-07)A series of W. R. Grace Davison IOLA(TM), methylaluminoxane-silica (MAO/Silica) and MAO/IOLA support materials were used to activate and immobilize a zirconium amidinate single site catalyst of the formula Cp*ZrMe2[tBuNC(Me)NCEt]. ... -
Evaluation of Acetonitrile Precipitation as a Method for Separating Small from High Molecular Mass Proteins in Cytosol from MCF-7 Breast Cancer Cells.
(2004-05-18)Acetonitrile precipitation has been carried out as an investigative method for separating small from high molecular mass proteins. The separation has been visualized on a 1-D gel electrophoresis. Acetonitrile helps drive ... -
Allostery and GroEL: Exploring the Tenets of Nested Cooperativity
(2004-06-24)Despite a wealth of structural and biochemical studies on the functional cycle of the <i>E. coli</i> chaperonins GroEL and GroES, no model proposed to date accounts for all the effects seen experimentally by ... -
The role of the F spin-orbit excited state in the F+H2 and F+HD reactions
(2004-07-22)In this dissertation we study the role of the F spin-orbit excited state (F*) in the F+H2 and F+HD reactions using quantum mechanical calculations. The calculations involve multiple potential energy surfaces (the ... -
Molecular Structure and Surface Organization: A Study of Liquid/Vapor Interfaces Using Newly Developed Sum Frequency Methods
(2004-08-19)Vibrational sum frequency spectroscopy (VSFS) is a surface specific nonlinear technique that provides vibrational spectra of molecules at interfaces. Studies presented in this thesis use VSFS to examine surface structure ... -
Airborne Characterization of Regional Aerosol Origins and Optical Properties
(2004-08-31)The ubiquity of air pollution in the Mid-Atlantic and northeastern U.S. is a major concern for human and ecological health as well as the climate. Between February 2001 and February 2004, 160 flights on a light aircraft ... -
COMPARATIVE PROTEOMICS STUDIES OF SOLUBLE NUCLEAR PROTEINS OF DRUG SUSCEPTIBLE AND RESISTANT HUMAN BREAST CANCER MCF-7 CELLS
(2004-10-05)Drug resistance is a major obstacle in cancer chemotherapy. Better understanding of the mechanisms of the drug resistance can help to improve clinical treatment and develop new drugs. Since most anticancer drugs target the ... -
NMR studies of polyubiquitin chains: insights into structural basis of functional diversity
(2004-10-25)Signaling by polyubiquitin (polyUb) chains mediates numerous cellular processes. All these processes involve the covalent modification of the substrate protein with a polyubiquitin chain that is itself formed by isopeptide ... -
MORPHOLOGICAL INSTABILITIES AND STEP PATTERN FORMATION ON VICINAL SURFACES
(2004-10-26)Vicinal surfaces can exhibit a number of different instabilities and step pattern formation that are important in directed growth and nanofabrication. This dissertation attempts to present some theoretical progress made ... -
Synthesis and Characterization of Binary Clusters to Controllable Binary Nanoparticles "The New Role of Zintl Anions"
(2004-10-27)Zintl anions are best described as polyatomic main group clusters (i.e. E73-; E = P, As, Sb) with structures characteristic of isoelectronic clusters (i.e. hydrocarbon and borohydride clusters). Combining these main ... -
Charged Antiparticle to Particle Ratios Near Midrapidity in d+Au and p+p Collisions at sqrt(s_NN) = 200 GeV
(2004-10-28)Experiments at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are designed to investigate the behavior of strongly interacting matter at high temperatures and densities. The conditions created ... -
A GAS-INJECTION NEGATIVE ION SOURCE FOR ACCELERATOR MASS SPECTROMETRY
(2004-11-04)Accelerator mass spectrometry is an ultra-sensitive isotopic analysis technique that allows for the determination of rare long-lived radionuclides such as radiocarbon. Historically, the technique has required that samples ... -
A Thermodynamic Investigation into the Allosteric Activation Mechanism of the Biotin Repressor
(2004-11-05)The biotin regulatory system of Escherichia coli serves as a model for investigating the regulatory mechanism of a non-classical allosteric transcription factor. The central protein, BirA, functions as both an essential ...