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Bisthioether Stapled Peptides Targeting Polycomb Repressive Complex 2 Gene Repression, Gan Zhang 2019 The Graduate Center, City University of New York

Bisthioether Stapled Peptides Targeting Polycomb Repressive Complex 2 Gene Repression, Gan Zhang

All Dissertations, Theses, and Capstone Projects

Interactions between proteins play a key role in nearly all cellular process, and therefore, disruption of such interactions may lead to many different types of cellular dysfunctions. Hence, pathologic protein-protein interactions (PPIs) constitute highly attractive drug targets and hold great potential for developing novel therapeutic agents for the treatment of incurable human diseases. Unfortunately, the identification of PPI inhibitors is an extremely challenging task, since traditionally used small molecule ligands are mostly unable to cover and anchor on the extensive flat surfaces that define those binary protein complexes. In contrast, large biomolecules such as proteins or peptides are ideal fits ...


Modeling Solid-Phase Microextraction Of Volatile Organic Compounds By Porous Coatings Using Finite Element Analysis, Bulat Kenessov, Miras Derbissalin, Jacek A. Koziel, Dmitry S. Kosyakov 2019 Al-Farabi Kazakh National University

Modeling Solid-Phase Microextraction Of Volatile Organic Compounds By Porous Coatings Using Finite Element Analysis, Bulat Kenessov, Miras Derbissalin, Jacek A. Koziel, Dmitry S. Kosyakov

Agricultural and Biosystems Engineering Publications

Experimental optimization of analytical methods based on solid-phase microextraction (SPME) is a complex and labor-intensive process associated with uncertainties. Using theoretical basics of SPME and finite element analysis software for the optimization proved to be an efficient alternative. In this study, an improved finite element analysis-based model for SPME of volatile organic compounds (VOCs) by porous coatings was developed mainly focussing on the mass transport in coatings. Benzene and the Carboxen/polydimethylsiloxane (Car/PDMS) coating were used as the model VOC and a porous SPME coating, respectively. It has been established that in the coating, volumetric fractions of Carboxen, PDMS ...


Protein Conformations In The Gas Phase Probed By Mass Spectrometry And Molecular Dynamics Simulations, Maryam Bakhtiari 2019 The University of Western Ontario

Protein Conformations In The Gas Phase Probed By Mass Spectrometry And Molecular Dynamics Simulations, Maryam Bakhtiari

Electronic Thesis and Dissertation Repository

Mass Spectrometry (MS) has been revolutionized by the ability to produce intact gaseous protein ions by electrospray ionization (ESI). The question to what extent these ions retain solution-like conformations under “native” ESI conditions remains a matter of debate. Traditional high-resolution structure determination techniques only report on proteins in the condensed phase. For this reason, MD simulations play an important role in exploring the behavior of gas phase proteins. In this research, mobile and non-mobile proton MD simulations along with mass spectrometry data at 300 K in both positive and negative ion mode indicated that native-like conformations were largely retained. Surface ...


Effect Of Dissolved Salts On The Physiochemical Properties Of Deep Eutectic Solvents, Eleanor Haeska, Megan Radtke 2019 South Dakota State University

Effect Of Dissolved Salts On The Physiochemical Properties Of Deep Eutectic Solvents, Eleanor Haeska, Megan Radtke

The Journal of Undergraduate Research

Green chemistry seeks to make chemical procedures safer, improve reaction efficiency, and utilize environmentally safe reagents. Deep eutectic solvents (DES) have recently become of great interest due to their eco-friendly nature and functionality as solvent for various chemical processes. One key characteristic of DES is their conductive nature and depressed melting point. This project sought to determine the effect of the addition of aqueous solutions of halides on the conductivity of two selected types of DES. Also assessed were the polarity and viscosity of the DES. It can be concluded that aqueous halides had no measureable effect on the conductivity ...


Increased Perchlorate In The Environment Following The 1600 C.E. Huaynaputina Volcanic Eruption, Joseph Gibson, Amanda Shea 2019 South Dakota State University

Increased Perchlorate In The Environment Following The 1600 C.E. Huaynaputina Volcanic Eruption, Joseph Gibson, Amanda Shea

The Journal of Undergraduate Research

Perchlorate is an environmental contaminant that can have adverse health effects on humans. Although our knowledge about how natural perchlorate is formed is very limited, volcanic eruptions are believed to play an important role. An ice core obtained from Summit Station, Greenland was used to study the effects of the Huaynaputina eruption on the amount of perchlorate in the environment. The section of ice core sampled was determined to span the years 1594 through 1610. The results indicate that the Huaynaputina eruption caused a temporary but significant increase in the amount of perchlorate in the atmosphere.


Atomic Force Microscopy Tip-Enhanced Laser Ablation, Fan Cao 2019 Louisiana State University and Agricultural and Mechanical College

Atomic Force Microscopy Tip-Enhanced Laser Ablation, Fan Cao

LSU Doctoral Dissertations

In the present work, an apertureless atomic force microscope (AFM) tip-enhanced laser ablation (TELA) system was developed and investigated. An AFM was coupled to an optical parametric oscillator (OPO) wavelength tunable laser for sample ablation with a submicron sampling size. The AFM was used to image the surface and hold the AFM tip 10 nm above the sample surface. The AFM tip is coated with a layer of gold with a thickness of 35 nm. The incident laser wavelength was tuned in the visible and near-infrared (IR) region and focused on the AFM tip. With the tip-enhancement effect, ablation craters ...


Urease Is An Essential Component Of The Acid Response Network Of Staphylococcus Aureus And Is Required For A Persistent Murine Kidney Infection, Chunyi Zhou, Fatema Bhinderwala, McKenzie K. Lehman, Vinai C. Thomas, Sujata S. Chaudhari, Kelsey J. Yamada, Kirk W. Foster, Robert Powers, Tammy Kielian, Paul D. Fey 2019 University of Nebraska Medical Center

Urease Is An Essential Component Of The Acid Response Network Of Staphylococcus Aureus And Is Required For A Persistent Murine Kidney Infection, Chunyi Zhou, Fatema Bhinderwala, Mckenzie K. Lehman, Vinai C. Thomas, Sujata S. Chaudhari, Kelsey J. Yamada, Kirk W. Foster, Robert Powers, Tammy Kielian, Paul D. Fey

Faculty Publications -- Chemistry Department

Staphylococcus aureus causes acute and chronic infections resulting in significant morbidity. Urease, an enzyme that generates NH3 and CO2 from urea, is key to pH homeostasis in bacterial pathogens under acidic stress and nitrogen limitation. However, the function of urease in S. aureus niche colonization and nitrogen metabolism has not been extensively studied. We discovered that urease is essential for pH homeostasis and viability in urea-rich environments under weak acid stress. The regulation of urease transcription by CcpA, Agr, and CodY was identified in this study, implying a complex network that controls urease expression in response to changes ...


Highly Stable And Efficient All-Inorganic Lead-Free Perovskite Solar Cells With Native-Oxide Passivation, Min Chen, Ming-Gang Ju, Hector F. Garces, Alexander D. Carl, Luis K. Ono, Zafer Hawash, Yi Zhang, Tianyi Shen, Yabing Qi, Ronald L. Grimm, Domenico Pacifici, Xiao Cheng Zeng, Yuanyuan Zhou, Nitin P. Padture 2019 Brown University

Highly Stable And Efficient All-Inorganic Lead-Free Perovskite Solar Cells With Native-Oxide Passivation, Min Chen, Ming-Gang Ju, Hector F. Garces, Alexander D. Carl, Luis K. Ono, Zafer Hawash, Yi Zhang, Tianyi Shen, Yabing Qi, Ronald L. Grimm, Domenico Pacifici, Xiao Cheng Zeng, Yuanyuan Zhou, Nitin P. Padture

Faculty Publications -- Chemistry Department

There has been an urgent need to eliminate toxic lead from the prevailing halide perovskite solar cells (PSCs), but the current lead-free PSCs are still plagued with the critical issues of low efficiency and poor stability. This is primarily due to their inadequate photovoltaic properties and chemical stability. Herein we demonstrate the use of the lead-free, allinorganic cesium tin-germanium triiodide (CsSn0.5Ge0.5I3) solid-solution perovskite as the light absorber in PSCs, delivering promising efficiency of up to 7.11%. More importantly, these PSCs show very high stability, with less than 10% decay in efficiency after ...


Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar 2019 Purdue University

Role Of Water On The Rotational Dynamics Of The Organic Methylammonium Cation: A First Principles Analysis, Ross D. Hoehn, Joseph S. Francisco, Sabre Kais, Ali Kachmar

Faculty Publications -- Chemistry Department

Understanding the degradation mechanisms of lead-halide perovskites (CH3NH3PbI3) under exposure to liquid/aerosol water is an essential problem within the photovoltaic community. Herein we investigate both the static and the dynamic properties of the methylammonuim cation (MA) as it coordinates with invading water molecules (MA.(H2O)n, n = 1, 2, 3, 4) using both stationary state quantum mechanics and first principle molecular dynamics simulations. Various solvation structures of MA were characterized by their stabilization energies, dipoles, and Maximally-Localized Wannier Function (MLWF) centers. Calculation – and analysis – of vibrational shifts in the IR spectral region ...


The Investigation Of The Chlorine Initiated Oxidation Of 2-Phenylethanol And Stability Of Superalkali Lithium Substituted Silyls., Adam Otten 2018 The University of San Francisco

The Investigation Of The Chlorine Initiated Oxidation Of 2-Phenylethanol And Stability Of Superalkali Lithium Substituted Silyls., Adam Otten

Master's Theses

This thesis investigates the combustion potential of 2-phenylethanol and the superalkali properties of small lithium substituted silicon compounds. All combustion experiments were performed at the Advanced Light Source of Lawrence Berkeley National Laboratory at the Chemical Dynamics Beamline 9.0.2. The chlorine initiated oxidation of 2PE was investigated at 298 and 550 K using a multiplex photoionization mass spectrometer, coupled with the tunable vacuum ultraviolet radiation. Reaction products were identified using kinetic time traces and photoionization spectra.

Additionally, the stability of small superalkali silicon-lithium compounds has also been investigated. All structures and energetics were calculated using the CBS-QB3 composite ...


Detection And Melting Of Surface-Bound Dna Using A Purely Electrochemical Approach, Denny Ho 2018 The University of San Francisco

Detection And Melting Of Surface-Bound Dna Using A Purely Electrochemical Approach, Denny Ho

Master's Theses

In this thesis, we demonstrate an electrochemical approach for monitoring the electric-field induced melting of surface-bound double-stranded DNA. The electrochemical routine involves repeated chronoamperometry pulses to melt the duplex and square wave voltammetry to monitor the extent of melting. We utilize a scanning potential and constant potential technique to generate melting curves and access the stability and kinetics of the DNA duplexes. Our method uses a mixed monolayer of thiol-modified DNA oligomers and mercaptohexanol on gold electrodes, are subsequently incubated with target DNA covalently modified with electroactive methylene blue. Under room temperature, 10 mM Tris, and optimized electrochemical parameters, DNA ...


Relative Permittivity As A Function Of Co-Solvent And Impedance Spectroscopy For Quantifying Anions In Solution, Yahya Sami Alseiha 2018 East Tennessee State University

Relative Permittivity As A Function Of Co-Solvent And Impedance Spectroscopy For Quantifying Anions In Solution, Yahya Sami Alseiha

Electronic Theses and Dissertations

This work measured relative permittivity from 15.0 to 55.0 °C of aqueous solutions containing acetone or tetrahydrofuran using a BI 870 dielectric meter. A cubic polynomial fit resulted in coefficients for calculating permittivity as a function of temperature and mole fraction. Literature values for other co-solvent system resulted in similar polynomial coefficients. Using BI 870, permittivity measurements of ionic solutions were not possible because of high conductivity. A simple method using impedance spectroscopy measured these solutions. Impedance decreases with increasing temperature and decreases with increasing ionic strength. Due to the temperature dependence of impedance, all measurements were at ...


Consumption Profiles Of Illicit And Neuropsychiatric Drugs In Urban And Rural Communities In Kentucky Using Sewage Epidemiology, Tara Croft, Katelyn Foppe, Rhiannon Huffines, Bikram Subedi 2018 Murray State University

Consumption Profiles Of Illicit And Neuropsychiatric Drugs In Urban And Rural Communities In Kentucky Using Sewage Epidemiology, Tara Croft, Katelyn Foppe, Rhiannon Huffines, Bikram Subedi

Posters-at-the-Capitol

The drug overdose deaths in the USA increased by ~20% from 2015 to 2016 to the total >63,600 drug overdose deaths in 2016. Kentucky is among the highest rate of drug overdose death states in the USA. The current estimates of the prevalence of substance abuse are based on the self-reported surveys, overdose/toxicological reports, and drug-related crime statistics. Survey-based conventional approaches are not only cost and time-intensive but also underestimate the actual consumption of drugs. As “wastewater never lie,” the drug residues in raw wastewater collected from the centralized wastewater treatment plants were utilized to determine the consumption ...


34 - Using Atomic Force Microscopy To Image Metal Sulfide Nanoparticles, Martin Driggers, Tatiana Mendoza, George Chumanov 2018 Clemson University

34 - Using Atomic Force Microscopy To Image Metal Sulfide Nanoparticles, Martin Driggers, Tatiana Mendoza, George Chumanov

Georgia Undergraduate Research Conference (GURC)

Using Atomic Force Microscopy to Image Metal Sulfide Nanoparticles

Martin Driggers, Tatiana Estrada-Mendoza, and Professor George Chumanov

Department of Chemistry, Clemson University

This research project is focused on the use of Atomic Force Microscopy (AFM) to image metal sulfide nanoparticles. The nanoparticles were synthesized in a solution by reacting metal salts with sodium sulfide in the presence of a silica matrix and have the potential for many applications including electronics, photovoltaics, and biomedical diagnostic. With the right concentrations of sulfur, silica, and metal ions, non-aggregated metal sulfide nanoparticles can be synthesized in an aqueous solution, stabilized by silica. The size ...


The Electrochemical Study Of Simulated Spent Nuclear Fuel (Simfuel) Corrosion Under Permanent Disposal Conditions, Ziyan Zhu 2018 The University of Western Ontario

The Electrochemical Study Of Simulated Spent Nuclear Fuel (Simfuel) Corrosion Under Permanent Disposal Conditions, Ziyan Zhu

Electronic Thesis and Dissertation Repository

The safety assessment of spent nuclear fuel under permanent disposal conditions requires examination of the corrosion of the spent fuel waste form (UO2) inside a failed waste container. The objective of this research project was to develop a detailed mechanism of the UO2 corrosion process when exposed to groundwater. The redox conditions within a failed container in a deep geologic repository will be complex. The oxidant, H2O2, produced by the α-radiolysis of groundwater, will be the main driving force for fuel corrosion. However, the efficiency of fuel dissolution will be determined by the competition between ...


Mass Spectrometry And Nuclear Magnetic Resonance In The Chemometric Analysis Of Cellular Metabolism, Eli Riekeberg 2018 University of Nebraska - Lincoln

Mass Spectrometry And Nuclear Magnetic Resonance In The Chemometric Analysis Of Cellular Metabolism, Eli Riekeberg

Student Research Projects, Dissertations, and Theses - Chemistry Department

The development and awareness of Machine Learning and “big data” has led to a growing interest in applying these methods to bioanalytical research. Methods such as Mass Spectrometry (MS), and Nuclear Magnetic Resonance (NMR) can now obtain tens of thousands to millions of data points from a single sample, due to fundamental instrumental advances and ever-increasing resolution. Simple pairwise comparisons on datasets of this magnitude can obfuscate more complex underlying trends, and does a disservice to the richness of information contained within. This necessitates the need for multivariate approaches that can more fully take advantage of the complexity of these ...


‘Cassette’-Ises (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds For Hydrolytic Kinetic Resolution Across A Range Of Epoxides, Sangeeta Dey, Douglas R. Powell, Chunhua Hu, David B. Berkowitz 2018 University of Nebraska - Lincoln

‘Cassette’-Ises (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds For Hydrolytic Kinetic Resolution Across A Range Of Epoxides, Sangeeta Dey, Douglas R. Powell, Chunhua Hu, David B. Berkowitz

Faculty Publications -- Chemistry Department

‘Cassette’-ISES (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds for Hydrolytic Kinetic Resolution Across a Range of Epoxides

A new ‘Cassette’-In Situ Enzymatic Screen (ISES) for combinatorial catalysis is introduced. This allows the experimentalist to obtain an information-rich readout, in real time, providing an estimate of the sense and magnitude of enantioselectivity across more than one substrate. In its first iteration, the screen identified CoIII-salen catalysts with β-pinene- and α-naphthylalanine-derived chiral scaffolds with broad, yet complementary, substrate specificities.


Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman 2018 University of Kentucky

Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman

Chemistry Faculty Publications

Heterogeneous photocatalysis is a prominent area of research with major applications in solar energy conversion, air pollution mitigation, and removal of contaminants from water. A large number of scientific papers related to the photocatalysis field and its environmental applications are published in different journals specializing in materials and nanomaterials. However, many problems exist in the conception of papers by authors unfamiliar with standard characterization methods of photocatalysts as well as with the procedures needed to determine photocatalytic activities based on the determination of “apparent quantum efficiencies” within a wavelength interval or “apparent quantum yields” in the case of using monochromatic ...


Developing A New Sensing Technology For Double-Stranded Dna Detection Utilizing Engineered Zinc Finger Proteins And Nanomaterials, Dat Thinh Ha 2018 Western Kentucky University

Developing A New Sensing Technology For Double-Stranded Dna Detection Utilizing Engineered Zinc Finger Proteins And Nanomaterials, Dat Thinh Ha

Masters Theses & Specialist Projects

A specific double-stranded DNA sensing system is of great interest for diagnostic and other biomedical applications. Zinc finger domains, which recognize double-stranded DNA, can be engineered to form custom DNA-binding proteins for recognition of specific DNA sequences. As a proof of concept, a sequence-enabled reassembly of TEM-1 β- lactamase system (SEER-LAC) was previously demonstrated to develop zinc finger protein (ZFP) arrays for the detection of a double-stranded bacterial DNA sequence. Here, we implemented the SEER-LAC system to demonstrate the direct detection of pathogenspecific DNA sequences present in E. coli O157:H7 on the lab-on-a chip. ZFPs customdesigned to detect shiga ...


Nanoparticle Microarray For High-Throughput Microbiome Metabolomics Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry, Rebecca L. Hansen, Maria Emilia Duenas, Torey Looft, Young Jin Lee 2018 Iowa State University

Nanoparticle Microarray For High-Throughput Microbiome Metabolomics Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry, Rebecca L. Hansen, Maria Emilia Duenas, Torey Looft, Young Jin Lee

Chemistry Publications

A high-throughput matrix-assisted laser desorption/ionization mass spectrometry (MALDI)-MS-based metabolomics platform was developed using a pre-fabricated microarray of nanoparticles and organic matrices. Selected organic matrices, inorganic nanoparticle (NP) suspensions, and sputter coated metal NPs, as well as various additives, were tested for metabolomics analysis of the turkey gut microbiome. Four NPs and one organic matrix were selected as the optimal matrix set: α-cyano-4-hydroycinnamic acid, Fe3O4 and Au NPs in positive ion mode with 10 mM sodium acetate, and Cu and Ag NPs in negative ion mode with no additive. Using this set of five matrices, over two thousand unique ...


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