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Full-Text Articles in Physical Sciences and Mathematics

The Regulation Of Atg9a-Mediated Aggrephagy By An Ulk1-Independent Atg13-Atg101 Complex, Joshua Youngs Jun 2022

The Regulation Of Atg9a-Mediated Aggrephagy By An Ulk1-Independent Atg13-Atg101 Complex, Joshua Youngs

Undergraduate Honors Theses

Aggrephagy, a type of autophagy, is an essential cellular process by which protein aggregates are collected and broken down in the lysosome. Protein aggregates are implicated in several diseases including Alzheimer’s disease, diabetes, and cancer. Here, we investigate the ATG13-ATG101 protein complex, a sub-complex of the canonical ULK1 complex whose regulatory role in aggrephagy is not completely understood. We also develop a protein fragment complementation (PFC) assay using the biotin ligase TurboID to study the functions of the ATG13-ATG101 complex with increased specificity. We demonstrate that ATG13 is required for optimal degradation of p62-ubiquitin condensates. We also show that a …


A Fret Flow Cytometry-Based Screening Assay For Multiplex Analysis Of Metabolites In T. Brucei, Ronald A. Zegarra Jun 2021

A Fret Flow Cytometry-Based Screening Assay For Multiplex Analysis Of Metabolites In T. Brucei, Ronald A. Zegarra

Undergraduate Honors Theses

Kinetoplastid parasites are a significant public health issue in some tropical and subtropical regions of the world. Kinetoplastid parasites all require glycolysis for survival, with host glucose key for ATP production. One such parasite, Trypanosoma brucei, exclusively metabolizes glucose in its bloodstream form. Trypanosomal glycolysis is unique because it displays unconventional structural features. Hence, glucose metabolism has been studied extensively in T. brucei and is a therapeutic target in kinetoplastid parasites.The lack of in vivo analytical techniques for measuring vital glycolytic metabolites in situ has restricted the ability of researchers to test, with high sensitivity and specificity, the essential roles …


Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur Jun 2021

Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur

Undergraduate Honors Theses

This thesis explores the synthesis of fluorinated α,β-dehydroamino acids, specifically a fluorinated dehydrovaline derivative. Previous work has been done on the equivalent dehydrovaline derivative without fluorine present and this work builds toward the fluorinated version with the goal of comparing the two structurally. The synthesis presented here pulls from previous synthetic strategies employed for dehydrovaline while also exploring the synthetic impact of the electronegative fluorine atoms.


Telsam-Target Protein Fusions Can Form Diffraction-Quality Crystals Without Direct Inter-Polymer Contacts, Moriah Longhurst Mar 2021

Telsam-Target Protein Fusions Can Form Diffraction-Quality Crystals Without Direct Inter-Polymer Contacts, Moriah Longhurst

Undergraduate Honors Theses

X-ray diffraction is a robust method for determining the detailed 3D structures of specific proteins. However, this requires the formation of well-ordered protein crystals, a process that is time-consuming, expensive, and only has about a 10-30% success rate. New methods are needed to enable the efficient crystallization of challenging proteins. One such technique is explored here, which utilizes a protein polymer (the sterile alpha motif domain of the human protein translocation Ets leukemia, or TELSAM) as a crystallization chaperone to form a more ordered crystal lattice of target proteins and drive crystallization. This method was successfully used to crystallize, collect …


Building An Ins-1 Cdna Library For A Genome-Wide Crispr-Cas9 Screen, Idongesit Ekpo Aug 2020

Building An Ins-1 Cdna Library For A Genome-Wide Crispr-Cas9 Screen, Idongesit Ekpo

Undergraduate Honors Theses

By the year 2040, an estimated 642 million people are expected to have diabetes globally. Diabetes results from an elevation of metabolic stressors, such as glucotoxicity, lipotoxicity, oxidative stress and apoptosis. In type 2 diabetes, these stressful conditions contribute to the malfunction and loss of functional insulin-producing β-cells. Current treatment methods for diabetes include insulin therapy, islet transplant and anti-diabetes medication. These treatments are not curative and ignore other factors that contribute to the pathogenesis of diabetes beyond insulin resistance and islet β-cell failure. Previous research on β-cells has focused on ways to replace functional β-cell mass, trigger β-cell proliferation, …


Preparation And Detailed X-Ray Photoelectron Spectroscopy And Spectroscopic Ellipsometryanalysis Of Ultrathin Protective Coatings, Brian Ivins Johnson Oct 2019

Preparation And Detailed X-Ray Photoelectron Spectroscopy And Spectroscopic Ellipsometryanalysis Of Ultrathin Protective Coatings, Brian Ivins Johnson

Theses and Dissertations

Ultra-thin films (UTFs) are important in many applications, seen in the semiconductor industry, in chromatography, in sensing, in microfluidics, in aerospace, and in robotics. They also protect materials from corrosion, change surface energies, limit water intrusion into materials, allow material self-cleaning and self-healing, provide scratch resistance, and impart other specific chemical properties. In many cases, UTFs drastically alter surface properties and therefore their applications. It is imperative that proper and consistent characterization be performed on coatings to confirm and understand their desired properties. In Chapter two, Al oxidation under MgF2 protective layers is studied using real time X-ray photoelectron spectroscopy …


Preparation, Functionalization, And/Or Characterization By X-Ray Photoelectron Spectroscopy Of Carbon Surfaces For Biosensors And Other Materials, Varun Jain Aug 2019

Preparation, Functionalization, And/Or Characterization By X-Ray Photoelectron Spectroscopy Of Carbon Surfaces For Biosensors And Other Materials, Varun Jain

Theses and Dissertations

My dissertation is primarily divided into two parts. The first deals with the preparation, functionalization, and characterization of carbon surfaces prepared by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) as substrates for bioarrays. Part two discusses applications of XPS peak fitting in surface chemical analysis. Chapter 1, the introduction, includes (i) a discussion of the construction of bioarrays and the preparation of sputtered surfaces, e.g., by DCMS and HiPIMS, and also functionalization (bioconjugate) chemistry with special emphasis on the importance of covalent functionalization of surfaces, and (ii) a discussion of the surface characterization techniques and …


Computational Studies Of High-Oxidation State Main-Group Metal Hydrocarbon C-H Functionalization, Clinton R. King Aug 2019

Computational Studies Of High-Oxidation State Main-Group Metal Hydrocarbon C-H Functionalization, Clinton R. King

Theses and Dissertations

High-oxidation state main-group metal complexes are potential alternatives to transition metals for electrophilic C-H functionalization reactions. However, there is little known about how selection of the p-block, main-group metal and ligand impact C-H activation and functionalization thermodynamics and reactivity. Chapter 2 reports density functional theory (DFT) calculations used to determine qualitative and quantitative features of C-H activation and metal-methyl functionalization energy landscapes for reaction between high-oxidation state d10s0 InIII, TlIII, SnIV, and PbIV carboxylate complexes with methane. While the main-group metal influences the C-H activation barrier height in a periodic manner, the carboxylate ligand has a much larger quantitative impact …


The Investigation Of Secondary Particle Formation Initiated By Non-Prototypical Sources And The Role Of Amines In The Atmosphere, Emily Burrell Aug 2019

The Investigation Of Secondary Particle Formation Initiated By Non-Prototypical Sources And The Role Of Amines In The Atmosphere, Emily Burrell

Theses and Dissertations

This dissertation is a collection of works that investigate non-prototypical sources leading to new particle formation in the atmosphere. Particles play a major role in atmospheric chemistry. For example, particles are a component of smog and are commonly found in high concentrations under conditions of atmospheric inversions. In order to reconcile the difference between measured and modeled particle concentrations new mechanisms from non-prototypical sources for particle formation need to be determined. Formation of particles has frequently been modeled using classical nucleation theory (CNT). The first step in CNT is the nucleation step where molecular clusters form. In a second step, …


Computational Design And Analysis Of Molecular Ethylene Oligomerization Catalysts, Doo Hyun Kwon Jun 2019

Computational Design And Analysis Of Molecular Ethylene Oligomerization Catalysts, Doo Hyun Kwon

Theses and Dissertations

Linear alpha olefins (LAOs) are key petrochemical precursors for the synthesis of larger polymers, detergents, plasticizers, and lubricants. Most catalytic ethylene oligomerization processes generate a wide distribution of LAO carbon chain lengths. A major ongoing industrial challenge is to develop homogeneous catalysts that result in selective and tunable ethylene oligomerization to 1-hexene and 1-octene alkenes. Quantum mechanical calculations coupled with rapidly advancing technology have enabled the ability to calculate small molecule systems with high accuracy. Employing computational models to advance from empirical to quantitative prediction of product selectivities has become an active area of exploration. In this work, we demonstrate …


The Investigation Of Nickel-Based Catalysts For The Oxidative Dehydrogenation Of Ethane, Justin Lane Park Apr 2019

The Investigation Of Nickel-Based Catalysts For The Oxidative Dehydrogenation Of Ethane, Justin Lane Park

Theses and Dissertations

The Investigation of Nickel-Based Catalysts for the Oxidative Dehydrogenation of Ethane Justin Lane ParkDepartment of Chemistry & Biochemistry, BYU Doctor of Philosophy Chemistry The advancement of creating ethylene from ethane via oxidative dehydrogenation (ODH) rather than the traditional direct dehydrogenation is right on the cusp of commercialization. The oxidative pathway provides a novel route that reduces the operating temperature of this reaction by 400-500°C. A variety of metals including Mo, V, and Ni that have redox properties suitable for the partial oxidation of small chain alkanes have been investigated. Currently, a MoVNbTe oxide is the most promising catalyst but it …


Multi-Instrument Surface Characterization Of Display Glass, Cody Vic Cushman Apr 2019

Multi-Instrument Surface Characterization Of Display Glass, Cody Vic Cushman

Theses and Dissertations

Flat panel displays (FPDs) are microfabricated devices that are often fabricated on specialized glass substrates known as display glass. The surface chemistry of the outer few nanometers of display glass can have an important influence on FPD performance and yield. Dsiplay glass surface characterization is difficult because (i) display glass surface composition varies significantly from its bulk composition; (ii) high-surface area forms of glass, such as fibers and powders, may not have the same surface composition as melt-formed planar surfaces, and (iii) the surface composition of display glass may be altered through exposure to chemical treatments commonly used during flat …


Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari Mar 2019

Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari

Theses and Dissertations

The abstract is the summary of three different projects all centered around the generalidea of catalysis which is the general theme of research in the Michaelis laboratory. The firstproject focuses on development of a new heterogeneous catalyst for selective catalysis. In theMichaelis lab, we were interested in the potential of nanoparticle catalysts for regioselectivetransformations. We showed that polymer supported ruthenium nanoparticles performed as areliable catalyst for regioselective reduction of azide to amine. In our study of regioselectivereduction of multiple azide containing substrates, we observed that in presence of ourruthenium nanoparticle catalysts, the least sterically hindered azide group reduced to aminefunctional …


Applications Of Pattern Recognition Entropy (Pre) And Informatics To Data Analysis, Shiladitya Chatterjee Mar 2019

Applications Of Pattern Recognition Entropy (Pre) And Informatics To Data Analysis, Shiladitya Chatterjee

Theses and Dissertations

The primary focus of my work is the application of informatics methods to the fields of materials science and analytical chemistry. The statistical analysis of data has become increasingly important in understanding the properties of materials and analytes. Statistical methods like principal component analysis (PCA) and multivariate curve resolution (MCR) are widely used for analysis in chemistry and other fields given their ability to categorize spectra in an unsupervised way. PCA is relatively easy to apply and has appealing mathematical properties. However, the results can be challenging to interpret, even for experienced users. In contrast, MCR results can be more …


Nonlinear Optical Characterization Of Solids, Alex Farnsworth Dec 2018

Nonlinear Optical Characterization Of Solids, Alex Farnsworth

Undergraduate Honors Theses

Vibrational Sum Frequency Generation (VSFG) and the similar Second Harmonic Generation (SHG) are both classified as nonlinear optical phenomena, with the hallmark trait being that the input and output frequencies are different. Both of these systems are remarkable tools due to their surface specific nature. Still, there is much that is not known about the response from these systems, especially the nonresonant SFG response. We have worked to better understand SFG signal, specifically the nonresonant temporal profile. We have also collected results that call into question some underlying assumptions about time-based suppression methods when working with single crystal substrates.

As …


Application Of The Entropy Concept To Thermodynamics And Life Sciences: Evolution Parallels Thermodynamics, Cellulose Hydrolysis Thermodynamics, And Ordered And Disordered Vacancies Thermodynamics, Marko Popovic Jun 2018

Application Of The Entropy Concept To Thermodynamics And Life Sciences: Evolution Parallels Thermodynamics, Cellulose Hydrolysis Thermodynamics, And Ordered And Disordered Vacancies Thermodynamics, Marko Popovic

Theses and Dissertations

Entropy, first introduced in thermodynamics, is used in a wide range of fields. Chapter 1 discusses some important theoretical and practical aspects of entropy: what is entropy, is it subjective or objective, and how to properly apply it to living organisms. Chapter 2 presents applications of entropy to evolution. Chapter 3 shows how cellulosic biofuel production can be improved. Chapter 4 shows how lattice vacancies influence the thermodynamic properties of materials. To determine the nature of thermodynamic entropy, Chapters 1 and 2 describe the roots, the conceptual history of entropy, as well as its path of development and application. From …


Creation And Use Of Software For Analysis Of Kinetic Proteomic Experiments, Bradley C. Naylor Apr 2018

Creation And Use Of Software For Analysis Of Kinetic Proteomic Experiments, Bradley C. Naylor

Theses and Dissertations

In this dissertation, I will review the history and general strategies for performing kinetic proteomics. I will then demonstrate that I have published an open source, user-friendly program for other scientists to use to perform kinetic proteomics data analysis, as well as publishing a novel discovery of key ribosomal subunits being replaced within the lifetime of the ribosome, which was discovered through use of kinetic proteomics. Finally, I will discuss work that is ongoing to improve my software tool for use in human subjects, and work being done to combine kinetic proteomics with other global analysis methods to make novel …


Contribution Of Bulky <&Alpha>,<&Beta>-Dehydroamino Acids To The Proteolytic Stability Andenhanced Folding Of <&Beta>-Hairpins And Progress Towards The Total Synthesis Of Yaku<'>Amide A, Ankur Jalan Mar 2018

Contribution Of Bulky <&Alpha>,<&Beta>-Dehydroamino Acids To The Proteolytic Stability Andenhanced Folding Of <&Beta>-Hairpins And Progress Towards The Total Synthesis Of Yaku<'>Amide A, Ankur Jalan

Theses and Dissertations

This dissertation primarily covers the impact of bulky ,-dehydroamino acids on the proteolytic stability and enhanced folding of -hairpins. It partly describes the progress towards the total synthesis of yakuamide A, a potent anticancer peptide with an IC50 value of 14 ng/mL against leukemia cells. Proteins and peptides are a very attractive source of potential medicinal agents as they can target various protein“protein interactions that are implicated in several diseases and disorders. The global sales of peptide drugs in 2013 were estimated to be about $28 billion and are constantly rising at an appreciable rate. However, peptide drugs have a …


Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton Dec 2017

Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton

Theses and Dissertations

An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading …


Ion Trajectory Simulations And Design Optimization Of Toroidal Ion Trap Mass Spectrometers, Jessica Marie Higgs Dec 2017

Ion Trajectory Simulations And Design Optimization Of Toroidal Ion Trap Mass Spectrometers, Jessica Marie Higgs

Theses and Dissertations

Ion traps can easily be miniaturized to become portable mass spectrometers. Trapped ions can be ejected by adjusting voltage settings of the radiofrequency (RF) signal applied to the electrodes. Several ion trap designs include the quadrupole ion trap (QIT), cylindrical ion trap (CIT), linear ion trap (LIT), rectilinear ion trap (RIT), toroidal ion trap, and cylindrical toroidal ion trap. Although toroidal ion traps are being used more widely in miniaturized mass spectrometers, there is a lack of fundamental understanding of how the toroidal electric field affects ion motion, and therefore, the ion trap's performance as a mass analyzer. Simulation programs …


Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton Dec 2017

Capacity Of Human Immunodeficiency Virus Targeting Chimeric Antigen Receptor T Cells To Eliminate Follicular Dendritic Cells Bearing Human Immunodeficiency Virus Immune Complexes, Matthew T. Ollerton

Theses and Dissertations

An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading …


Semiconductor Terahertz Electronics And Novel High-Speed Single-Shot Measurements, Parker Dean Salmans Oct 2017

Semiconductor Terahertz Electronics And Novel High-Speed Single-Shot Measurements, Parker Dean Salmans

Theses and Dissertations

Ultrafast spectroscopy is used to study essential characteristics of solid-state materials. We use ultrafast techniques to study semiconductors at THz frequencies, as well as demonstrate new single-shot measurement techniques. The future of electronics is in the THz regime. We study a crucial characteristic of semiconductors used in devices: the critical field at which the material becomes conductive. GaAs is a promising semiconductor for high-speed devices, and we use enhanced THz electric fields to measure the critical fields at 0.7, 0.9, 1.1, and 1.5 THz frequencies. Single-shot spectroscopy is a technique used to measure ultrafast time scale laser pulses. We show …


Microwave-Promoted Iminyl Radical Cyclizations For The Synthesis Of Azaheterocycles And The Total Synthesis Of Yaku'amide A, Yu Cai Aug 2017

Microwave-Promoted Iminyl Radical Cyclizations For The Synthesis Of Azaheterocycles And The Total Synthesis Of Yaku'amide A, Yu Cai

Theses and Dissertations

Two different research projects are described in this dissertation. The first one focuses on microwave-promoted iminyl radical cyclization for the formation of azaheterocycles which are embedded within numerous pharmaceuticals and biologically active natural products (such as clindamycin, eletriptan, moxiflaxin, etc.). We are quite interested in this project because of the significance of nitrogen-containing heterocycles as pharmaceuticals and organocatalysts combined with the need for safe, simple, and economical means of constructing them. We have successfully developed an efficient one-step synthesis of 2-acylpyrroles and diastereoselective dihydropyrroles from readily available oxime ether substrates. This remarkably efficient and environmentally friendly methodology should be useful …


Advancements In The Understanding Of Nonlinear Optics And Their Use In Material Analysis, Shawn C. Averett Aug 2017

Advancements In The Understanding Of Nonlinear Optics And Their Use In Material Analysis, Shawn C. Averett

Theses and Dissertations

Adhesion, heterogeneous catalysis, electrochemistry, and many other important processes and properties are driven by interactions at surfaces and interfaces. Vibrational sum frequency generation spectroscopy (VSFG) is an increasingly popular analytical technique because it can provide information about the nature and physical orientation of functional groups at these surfaces and interfaces. Analysis of VSFG data can be complicated by the presence of SFG signal that is not associated with a resonant vibration. This nonresonant sum frequency generation (NR-SFG) signal can interfere with the resonant signal and influence the detected spectrum. Methods have been developed to remove NR-SFG signal; however, these methods …


Post-Translational Regulation Of Superoxide Dismutase 1 (Sod1): The Effect Of K122 Acylation On Sod1'S Metabolic Activity, Courtney Jean Banks Aug 2017

Post-Translational Regulation Of Superoxide Dismutase 1 (Sod1): The Effect Of K122 Acylation On Sod1'S Metabolic Activity, Courtney Jean Banks

Theses and Dissertations

Many mutations in superoxide dismutase 1 (SOD1) cause destabilization and misfolding of the protein and are implicated in amyotrophic lateral sclerosis. Likewise, a few post-translational modifications (PTMs) on SOD1 have been shown to cause the same phenotype. However, relatively few PTMs on SOD1 have been studied in depth and, in particular, very few studies have demonstrated how these PTMs affect SOD1's various biological roles. SOD1 is traditionally known for its role in reactive oxygen species (ROS)-scavenging but has also been found to have a few other biological roles, including transcription factor activity to promote genomic stability, preservation of cytoskeletal activity, …


Role Of Molecular Chaperonin Cct And Its Co-Chaperone Phlp1 In The Assembly Of Mtor Complexes, Madhura Vinayak Dhavale Aug 2017

Role Of Molecular Chaperonin Cct And Its Co-Chaperone Phlp1 In The Assembly Of Mtor Complexes, Madhura Vinayak Dhavale

Theses and Dissertations

mTOR is the central kinase in biochemical pathways that regulate cellular growth, protein synthesis and cell survival. Deregulation of mTOR signaling results in uncontrolled cell proliferation and hence is implicated in various cancers and autoimmune diseases. mTOR functions through two distinct signaling complexes, called mTORC1 and mTORC2. CCT is a cytosolic chaperonin that assists in folding of several protein substrates. In these studies, we have identified two components of the mTOR complexes, mLST8 and Raptor, as substrates of CCT. We have performed biochemical and signaling studies which indicate that CCT is involved in assembly and signaling of mTOR complexes by …


Microwave-Promoted Iminyl Radical Fragmentations: A Practical And Efficient Method Of Functionalization, Mary Megan Jackman Aug 2017

Microwave-Promoted Iminyl Radical Fragmentations: A Practical And Efficient Method Of Functionalization, Mary Megan Jackman

Theses and Dissertations

We report a novel fragmentation and functionalization method using a cyclic iminyl radical. Formation of this radical occurs by microwave heating under mild conditions and short reaction times. The reaction avoids the use of explosive or toxic radical initiators and propagating agents. This reaction is versatile, with the ability to install two functional groups that are ultimately derived from a ketone in the substrate precursor. A variety of radical traps capable of forming both carbon-carbon bonds and carbon-heteroatom bonds have been tested, and the products are obtained in good yields. We demonstrate the power of this reaction by functionalizing complex …


Electrokinetically Operated Integrated Microfluidic Devices For Preterm Birth Biomarker Analysis, Mukul Sonker Aug 2017

Electrokinetically Operated Integrated Microfluidic Devices For Preterm Birth Biomarker Analysis, Mukul Sonker

Theses and Dissertations

Microfluidics is a vibrant and expanding field that has the potential for solving many analytical challenges. Microfluidics shows promise to provide rapid, inexpensive, efficient, and portable diagnostic solutions that can be used in resource-limited settings. Microfluidic devices have gained immense interest as diagnostic tools for various diseases through biomarker analysis. My dissertation work focuses on developing electrokinetically operated integrated microfluidic devices for the analysis of biomarkers indicative of preterm birth risk. Preterm birth (PTB), a birth prior to 37 weeks of gestation, is the most common complication of pregnancy and the leading cause of neonatal deaths and newborn illnesses. In …


Electrophilic Catalysis Using Heterobimetallic Complexes, Whitney Kaye Walker Aug 2017

Electrophilic Catalysis Using Heterobimetallic Complexes, Whitney Kaye Walker

Theses and Dissertations

Conventional ligand design in transition metal catalysis capitalizes on the ability of phosphorous, nitrogen, carbon, oxygen, and sulfur-based donors to modify the steric and electronic properties of a reactive metal center. Heterobimetallic transition metal complexes that contain a dative metal-metal bond provide a unique approach to ligand design where the reactivity of the metal center can be modified by metal-metal electronic communication. Our laboratory is interested in using the unique properties of heterobimetallic complexes to address significant limitations in current transition metal catalysis. My PhD work has focused on the ability of early/late transition metal heterobimetallic complexes to facilitate catalysis …


Ion Trap Miniaturization Considerations: Space-Charge Effects In Cylindrical Ion Traps And Misalignment Effects In A Two-Plate Linear Ion Trap, Yuan Tian Aug 2017

Ion Trap Miniaturization Considerations: Space-Charge Effects In Cylindrical Ion Traps And Misalignment Effects In A Two-Plate Linear Ion Trap, Yuan Tian

Theses and Dissertations

Portable mass spectrometers provide convenience for applications where conventional mass spectrometers are not suitable. However, a series of miniaturization issues show up in small mass spectrometers, specifically mass analyzers, that need to be thoroughly addressed before further miniaturization. The work in this dissertation focuses on miniaturization issues of ion trap mass analyzers. Space-charge is one of the major issues in small ion traps affecting their analytical performance. It limits ion trapping capacity when ion-ion repulsion causes spreading of a packet of ions. Simulation studies on the relationship between different trap dimensions and trapping capacity was done on a geometry-optimized cylindrical …