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Full-Text Articles in Physical Sciences and Mathematics
Supersonic Jet Spectroscopy Of Synthetic Foldamers, Multichromophores, And Their Water Containing Clusters, Evan Gardner Buchanan
Supersonic Jet Spectroscopy Of Synthetic Foldamers, Multichromophores, And Their Water Containing Clusters, Evan Gardner Buchanan
Open Access Dissertations
A central theme specific to this dissertation concerns the conformation-specific spectroscopy of flexible molecules in an effort to bridge the complexity gap. Generally, molecules in the complexity gap have several flexible coordinates yet conformational isomerization still occurs along a simple reaction coordinate on the potential energy surface. Molecules in this regime benefit greatly from experiments probing the potential energy surfaces and provide a means to develop and test new theories in an effort to explain more complex system. These measurements are possible through the utilization of a supersonic jet expansion to collisionally cool molecules into their vibrational zero-point levels, collapsing …
Aircraft-Based Measurements For The Identification And Quantification Of Sources And Sinks In The Carbon Cycle, Dana R Caulton
Aircraft-Based Measurements For The Identification And Quantification Of Sources And Sinks In The Carbon Cycle, Dana R Caulton
Open Access Dissertations
Improved quantification of carbon-cycle sources and sinks is an important requirement for determining mitigation strategies and modeling future climate interactions. Analytically robust measurements require high-precision instrumentation and thoughtful experimental design to produce rigorous and reproducible results despite complex and quickly changing meteorological and environmental conditions. Here, an aircraft platform equipped with a high-precision cavity ring-down spectrometer for CO2, CH4 and H2O quantification was used to acquire data from previously un-sampled sources. The aircraft mass-balance technique was used to quantify CH4 emissions from natural gas well pads in the drilling stage, which were 2-3 orders of …
Determination Of Disulfide Bond Connecting Patterns Via Tandem Mass Spectrometry (Msn) And Biomolecular Ion/Radical Reactions, Kirt Lenroy Durand
Determination Of Disulfide Bond Connecting Patterns Via Tandem Mass Spectrometry (Msn) And Biomolecular Ion/Radical Reactions, Kirt Lenroy Durand
Open Access Dissertations
Disulfide bond formation is one of the most common post translational modifications to occur in proteins and naturally occurring peptides. Disulfide bond formation plays a critical role in stabilizing their three-dimensional structure; therefore, it is very important to pinpoint the correct disulfide bond connecting pattern in order to fully understand the biological functions of these proteins and peptides. To fully characterize an analyte containing disulfide bonds, the sequence must first be known followed by the disulfide bond connecting pattern. This presents an analytical challenge as there are very few methodologies that can produce those essential pieces of information. The gold …
Towards A Paradigm Shift In The Modeling Of Soil Organic Carbon Decomposition For Earth System Models, Yujie He
Open Access Dissertations
Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon dynamics and climate. However, these models often predict a wide range of soil carbon responses and their formulations have lagged behind recent soil science advances, omitting key biogeochemical mechanisms. In contrast, recent mechanistically-based biogeochemical models that explicitly account for microbial biomass pools and enzyme kinetics that catalyze soil carbon decomposition produce notably different results and …
Quantum Mechanics In Complex Systems, Ross Douglas Hoehn
Quantum Mechanics In Complex Systems, Ross Douglas Hoehn
Open Access Dissertations
This document should be considered in its separation; there are three distinct topics contained within and three distinct chapters within the body of works. In a similar fashion, this abstract should be considered in three parts. Firstly, we explored the existence of multiply-charged atomic ions by having developed a new set of dimensional scaling equations as well as a series of relativistic augmentations to the standard dimensional scaling procedure and to the self-consistent field calculations. Secondly, we propose a novel method of predicting drug efficacy in hopes to facilitate the discovery of new small molecule therapeutics by modeling the agonist-protein …
How Do Metalloenzymes Propagate And Control Chemical Reactions?, Whitney F Kellett
How Do Metalloenzymes Propagate And Control Chemical Reactions?, Whitney F Kellett
Open Access Dissertations
Enzymes control and propagate a dizzying array of chemical reactions, including radical reactions and reactions cleaving carbon-carbon bonds. Metalloenzymes, which contain a metal cofactor, are particularly adept at propagating these reactions. This thesis focuses on several metalloenzymes; each an example of a different unique reaction control strategy. Both experimental and computational methodologies have been employed in order to identify specific residues or features which contribute to each enzyme's ability to control the reaction. Emphasis is made on special properties of the metal Manganese. Controlling residues include not only first shell or active site residues, but also residues more distant from …
Development Of Novel Strategies To Combat Multidrug Resistance Mediated By Efflux Transporters And Intracellular Bacteria, Jerrin Kuriakose
Development Of Novel Strategies To Combat Multidrug Resistance Mediated By Efflux Transporters And Intracellular Bacteria, Jerrin Kuriakose
Open Access Dissertations
Multidrug resistance (MDR) is the condition where cancer cells or microorganisms cease to respond to multiple drugs. MDR conferred by efflux transporters, that deprive the bioavailability of drugs at their site of action, are a threat to cancer and malarial chemotherapy. Specifically, the mammalian ABC transporter Pglycoprotein (P-gp) has undermined many drugs in treatment of cancer and other disease states. Mutations in the parasitic transporter Plasmodium falciparum chloroquine resistance transporter (PfCRT) have given rise to strains unsusceptible to the aminoquionoline family of antimalarials. Using the very drug substrates, we have developed bivalent inhibitors of P-gp. Here, click chemistry has been …
The Modification Of Brucine Derivatives As Chiral Ligands And Its Application In The Asymmetric Synthesis, Jian-Yuan Li
The Modification Of Brucine Derivatives As Chiral Ligands And Its Application In The Asymmetric Synthesis, Jian-Yuan Li
Open Access Dissertations
The modification of brucine derivatives as chiral ligands and the use of a multifaceted chiral ligand, brucine diol, under different reaction conditions to produce various optical isomers is described. In Chapter 1, the generation of a number of brucine derivatives is described. Taking the advantage of brucine-diol's excellent molecular recognition capability for multiple organic functional groups, we focused on the synthetic modifications of brucine-diol and the synthesis of brucine N-oxide. We also produced various brucine derivatives with different functional moieties in good yields and selectivities. ^ In Chapter 2, we described the investigation of brucine N-oxide catalyzed Morita-Baylis-Hillman …
Transformation Of Biomass Carbohydrates By Transition Metal Catalysts, Christine M Bohn
Transformation Of Biomass Carbohydrates By Transition Metal Catalysts, Christine M Bohn
Open Access Dissertations
By selectively removing functional groups from biomass derived carbohydrates, valuable platform chemicals can be generated from renewable sources. Through dehydration chemistry glucose can be upgraded into 5-(Hydroxymethyl)-2-furfuraldehyde (HMF) and levulinic acid. Iron (III) chloride hexahydrate has shown moderate activity to transform glucose into HMF and has also shown high yields and selectivity for the production of levulinic acid. Typically synthesized from acidic solutions made with mineral acids, levulinic acid has now been produced in high yields with a metal salt. The difference between maximizing production for HMF or levulinic acid from the same catalyst relies on the control of the …
Excited States Of Chromophores And Vibronic Interactions, Benjamin T. Nebgen
Excited States Of Chromophores And Vibronic Interactions, Benjamin T. Nebgen
Open Access Dissertations
The main focus of my Ph.D. work has been on building a vibronic coupling model for multichromophores and extending that model to more general systems. This Dissertation serves as both a summary of this work as well as a manual for the two vibronic coupling programs I have written. It is my hope that the instructions written here are complete enough for any who would like to replicate my work on vibronic coupling on other systems. ^ Additionally, I have also worked on a few purely computational projects not directly related to the vibronic coupling work. The status of these …
New Experimental And Theoretical Tools For Studying Protein Systems With Elements Of Structural Disorder, Tairan Yuwen
New Experimental And Theoretical Tools For Studying Protein Systems With Elements Of Structural Disorder, Tairan Yuwen
Open Access Dissertations
Disordered proteins are one class of proteins which do not possess well-folded three-dimensional structures as their native conformations. Many eukaryotic proteins have been found to be fully disordered or contain certain disordered regions. Disordered proteins usually display several characteristic properties, such as increased motional freedom and the conformational heterogeneity caused by that. The elements of structural disorder are commonly involved in many important biological functions and are implicated in many diseases. Therefore, the study of disordered proteins has become one of the most important research topics in recent years. This thesis presents results from three different research projects; the common …
Metal-Protein Interactions For Proteomics Applications, Keerthi B Jayasundera
Metal-Protein Interactions For Proteomics Applications, Keerthi B Jayasundera
Open Access Dissertations
In the quest of deciphering biological mechanisms, the understanding of proteins and their functions is a vital component. However the complexity of the proteome poses an immense challenge for analytical chemists to explore it comprehensively. Currently mass spectrometry is at the forefront of proteome analysis, providing great capabilities to couple with modern separation techniques for wide applications. One major objective of current proteomic technologies is to identify proteins of interest among high background, in particular from complex biological samples. A variety of techniques have been developed over the years to simplify protein samples, which are broadly classified as enrichment, high …
Synthesis And Dna-Binding Studies With Two Stericallyfriendly Porphyrin Frameworks, Srijana Ghimire
Synthesis And Dna-Binding Studies With Two Stericallyfriendly Porphyrin Frameworks, Srijana Ghimire
Open Access Dissertations
Peripheral substituents on cationic porphyrins play a significant role during binding with DNA hosts. Possible applications of these systems in photodynamic therapy as well as in anti-bacterial and anti-cancer therapies motivate the binding studies. For characterizing DNA binding motifs different methods are useful including absorption, emission, and circular dichroism spectroscopies, as well as viscometry and X-ray crystallography. With the classic H2 T4 porphyrin, or 5,10,15,20-tetra(N-methylpyridinium-4-yl)porphyrin, the mode of binding varies with the base composition of the DNA host. The porphyrin binds adenine-thymine rich sequences externally whereas intercalation occurs in guanine-cytosine rich sequences. The McMillin group has made some …
Fundamental Studies On Copper Zeolites For Catalytic No X Abatement, Anuj Arun Verma
Fundamental Studies On Copper Zeolites For Catalytic No X Abatement, Anuj Arun Verma
Open Access Dissertations
Stringent regulations in mobile NOx emissions have resulted in the development of Standard Selective Catalytic Reduction (SCR) as the dominant NOx abatement technology in lean burn diesel engines. Standard SCR is a reaction of nitric oxide (NO) with ammonia (NH3), in the presence of oxygen (O 2) to form nitrogen (N2) and water (H2O). Copper containing zeolites show commercially viable SCR performance. Cu-SSZ-13 (CHA framework), a member of this family, is a preferred catalyst for SCR applications because it shows exceptional hydrothermal stability in addition to commercially viable SCR performance. Our work focuses …
Reactivity Studies Of Tridhydropyridine Radical Cautions By Using Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry And Advancement Of Mass Spectrometric Analysis Of Asphaltenes And Degradation Products, Mohammad Sabir Aqueel
Open Access Dissertations
Aromatic organic molecules which have unpaired electrons play an important role in a variety of applications in the fields of organic synthesis, organic magnets, and biological activity of organic compounds. Several studies have been published on σ- type carbon-centered mono- and biradicals. Reactive intermediates with three formally unpaired electrons are known as triradicals. They can be defined as species with three electrons distributed in three degenerate or nearly degenerate orbitals, based on Salem's definition of biradicals from the electronic structure point of view. Very little is known about the reactivity of carbon-centered σ,σ,σ- triradicals due to the complexity of studying …
Dj-1 And Atp13a2: Two Proteins Involved In Parkinson’S Disease, Josephat M Asiago
Dj-1 And Atp13a2: Two Proteins Involved In Parkinson’S Disease, Josephat M Asiago
Open Access Dissertations
Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, affecting approximately 0.3% of the total U.S. population, and its prevalence increases with age. Two neuropathological hallmarks of PD are the loss of dopaminergic neurons in the substantia nigra pars compacta, a region in the midbrain involved in initiating and sustaining movement, and the presence of cytosolic inclusions called Lewy bodies (LBs) in various brain regions. LBs are enriched with fibrillar forms of the presynaptic protein &agr;-synuclein (aSyn). Two autosomal recessive genes implicated in familial PD are PARK9, encoding the P-type ATPase ATP13A2, a lysosomal ATPase; and …