Chemistry Commons^™

Effects Of Cerium Oxide Nanoparticles In Cereals: Insights Into The Toxicity Mechanisms And Macromolecular Modifications, Cyren Mendoza Rico

Open Access Theses & Dissertations

Despite the inundation of studies on the interaction of engineered nanomaterials (ENMs) with plants, investigations involving complete life cycle (i.e from seedling establishment to full maturity) are still lacking. Assessments on the nutritional value of plants cultivated to full maturity in ENMs-treated soil are also missing. Cerium oxide nanoparticles (nCeO2) have significant interactions with plants; however, there are no life cycle studies yet on their implications in cereals like rice (Oryza sativa L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.). These cereals are globally important crops that support the economic activity, and nutritional and health needs of billions …

Determination Of The Uptake And Effects Of Tio2 Nanoparticles In Cucumber (Cucumis Sativus), Alia D. Servin

Open Access Theses & Dissertations

The profuse use of nanoparticles (NPs) in consumer products has raised concerns about their impacts in environmental and human health and possible transfer into the food chain through plants. Cucumber (Cucumis sativus L.) is a widely cultivated garden vegetable that could be in contact with NPs through biosolids. In this Dissertation research, the impact of TiO2 NPs was evaluated in cucumber plants grown in hydroponics and sandy loam soil. Hydroponically grown plants were treated for 15 days with 0-4000 mg/L of TiO2 NPs, and their vegetative tissues were studied using synchrotron micro X-Ray Fluorescence (micro-XRF) and Micro X-ray Absorption Near …

Elemental Fingerprinting Using Inductively Coupled Plasma Mass Spectrometry And Chemometrics: Application To Environmental Science And Provenance Studies, Lorlyn Paquibot Reidy

Electronic Theses and Dissertations

No abstract provided.

Fabrication And Characterization Of High Surface Area Gold Electrodes, Madhura S. Damle

Theses and Dissertations

High surface area gold electrodes are very good substrates for biosensors, catalysis and drug delivery. Their performance is characterized by good sensitivity, low detection limit and high signal. As a result, extensive research is being carried out in this field using different approaches of fabrication to generate high surface area porous electrodes of different morphology, pore size and structure. The morphology of the electrodes can be changed based on whether the approach involves a template or not, types of metal deposition, method and time of dealloying etc. The deposition of metal can be carried out using various approaches such as …

Ferroelectric Hexagonal And Rhombic Monolayer Ice Phases, Wen-Hui Zhao, Jaeil Bai, Lan-Feng Yuan, Jinlong Yang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Two new phases of water, the mid-density hexagonal monolayer ice and the high-density flat rhombic monolayer ice, are observed in our molecular dynamics simulations of monolayer water confined between two smooth hydrophobic walls. These are in addition to the two monolayer ices reported previously, namely, the low-density 4∙8² monolayer ice and the high-density puckered rhombic monolayer ice (HD-pRMI). Stabilities of the structures are confirmed by ab initio computation. Importantly, both new phases and the HD-pRMI are predicted to be ferroelectric. An in-plane external electric field can further stabilize these ferroelectric monolayer ices.

Mos2/Mx2 Heterobilayers: Bandgap Engineering Via Tensile Strain Or External Electrical Field, Ning Lu, Hongyan Guo, Lei Li, Jun Dai, Lu Wang, Wai-Ning Mei, Xiaojun Wu, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX₂/MoS₂ (M = Mo, Cr, W, Fe, V; X = S, Se). For M = Mo, Cr, W; X = S, Se, all heterobilayers show semiconducting characteristics with an indirect bandgap with the exception of the WSe2/MoS2 heterobilayer which retains the directbandgap character of the constituent monolayer. For M = Fe, V; X = S, Se, the MX₂/MoS₂ heterobilayers exhibit metallic characters. Particular attention of this study has been focused on engineering the bandgap …

Van Der Waals Trilayers And Superlattices: Modification Of Electronic Structures Of Mos2 By Intercalation, Ning Lu, Hongyan Guo, Lu Wang, Xiaojun Wu, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a twodimensional (2D) monolayer (ML = BN, MoSe₂, WS₂, orWSe₂) between a MoS₂ bilayer to form various MoS₂/ML/MoS₂ sandwich trilayers. We find that the BN monolayer is themost effective sheet to decouple the interlayer vdW coupling of the MoS₂ bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS₂ monolayer, particularly the direct-gap character. Further study of the MoS₂/BN superlattices confirms the effectiveness of …

Unraveling Crystalline Structure Of High-Pressure Phase Of Silicon Carbonate, Rulong Zhou, Bingyan Qu, Jun Dai, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Although CO₂ and SiO₂ both belong to group-IV oxides, they exhibit remarkably different bonding characteristics and phase behavior at ambient conditions. At room temperature, CO₂ is a gas, whereas SiO₂ is a covalent solid with rich polymorphs. A recent successful synthesis of the silicon-carbonate solid from the reaction between CO₂ and SiO₂ under high pressure [M. Santoro et al., Proc. Natl. Acad. Sci. U.S.A. 108, 7689 (2011)] has resolved a long-standing puzzle regarding whether a Si_xC_1−xO₂ compound between CO₂ and SiO₂ exists in nature. Nevertheless, the detailed …

Mvapack: A Complete Data Handling Package For Nmr Metabolomics, Bradley Worley, Robert Powers

Robert Powers Publications

Data handling in the field of NMR metabolomics has historically been reliant on either in-house mathematical routines or long chains of expensive commercial software. Thus, while the relatively simple biochemical protocols of metabolomics maintain a low barrier to entry, new practitioners of metabolomics experiments are forced to either purchase expensive software packages or craft their own data handling solutions from scratch. This inevitably complicates the standardization and communication of data handling protocols in the field. We report a newly developed open-source platform for complete NMR metabolomics data handling, MVAPACK, and describe its application on an example metabolic fingerprinting data set.

Iterative Assembly Of Two Separate Polyketide Chains By The Same Single-Module Bacterial Polyketide Synthase In The Biosynthesis Of Hsaf, Yaoyao Li, Haotong Chen, Yanjiao Ding, Yunxuan Xie, Haoxin Wang, Ronald Cerny, Yuemao Shen, Liangcheng Du

Ronald Cerny Publications

HSAF (1) was isolated from the biocontrol agent Lysobacter enzymogenes (Figure 1).^[1-4]

This bacterial metabolite belongs to polycyclic tetramate macrolactams (PTM) that are

emerging as a new class of natural products with distinct structural features. ^{[5, 6]} HSAF

exhibits a potent antifungal activity and shows a novel mode of action.^[1-4] The HSAF

biosynthetic gene cluster contains only a single-module hybrid polyketide synthasenonribosomal

peptide synthetase (PKS-NRPS), although the PTM scaffold is apparently

derived from two separate hexaketide chains and an ornithine residue.^[1-4] This suggests that

the same PKS module would act not only iteratively, but also …

Three-Dimensional Periodic Graphene Nanostructures, Peter M. Wilson, Gilbert N. Mbah, Thomas G. Smith, Daniel Schmidt, Rebecca Y. Lai, Tino Hofmann, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Graphene is a basic building block for many known and emerging carbon-based materials whose properties largely depend on the way how graphene is structured at the nanoscale. Synthesis of novel threedimensional (3D) nanostructures of graphene would be an important advance for fundamental research and various applications. In this paper, we discuss the possibility of fabricating complex 3D graphene nanostructures by growing graphene on pre-synthesized nanostructured metal templates by chemical vapor deposition (CVD) and then etching away the metal. In the proof-of-concept experiments, we study this idea using two types of metal nanostructures, inverse opals and slanted nanopillar arrays grown by …

Bulk Properties Of Solution-Synthesized Chevron-Like Graphene Nanoribbons, Timothy H. Vo, Mikhail Shekhirev, Alexey Lipatov, Rafal A. Korlacki, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Graphene nanoribbons (GNRs) have received a great deal of attention due to their promise for electronic and optoelectronic applications. Several recent studies have focused on the synthesis of GNRs by the bottom-up approaches that could yield very narrow GNRs with atomically precise edges. One type of GNRs that has received a considerable attention is the chevron-like GNR with a very distinct periodic structure. Surface-assisted and solution-based synthetic approaches for the chevron-like GNRs have been developed, but their electronic properties have not been reported yet. In this work, we synthesized chevron-like GNRs in bulk by a solution-based method, characterized them by …

Highly Selective Gas Sensor Arrays Based On Thermally Reduced Graphene Oxide, Alexey Lipatov, Alexey Varezhnikov, Peter Wilson, Victor Sysoev, Andrei Kolmakov, Alexander Sinitskii

Department of Chemistry: Faculty Publications

The electrical properties of reduced graphene oxide (rGO) have been previously shown to be very sensitive to surface adsorbates, thus making rGO a very promising platform for highly sensitive gas sensors. However, poor selectivity of rGO-based gas sensors remains a major problem for their practical use. In this paper, we address the selectivity problem by employing an array of rGO-based integrated sensors instead of focusing on the performance of a single sensing element. Each rGO-based device in such an array has a unique sensor response due to the irregular structure of rGO films at different levels of organization, ranging from …

Structure And Function Of Preq1 Riboswitches, Catherine D. Eichhorn, Mijeong Kang, Juli Feigon

Department of Chemistry: Faculty Publications

PreQ₁ riboswitches help regulate the biosynthesis and transport of PreQ₁ (7-aminomethyl-7- deazaguanine), a precursor of the hypermodified guanine nucleotide queuosine (Q), in a number of Firmicutes, Proteobacteria, and Fusobacteria. Queuosine is almost universally found at the wobble position of the anticodon in asparaginyl, tyrosyl, histidyl and aspartyl tRNAs, where it contributes to translational fidelity. Two classes of PreQ₁ riboswitches have been identified (PreQ₁-I and PreQ₁-II), and structures of examples from both classes have been determined. Both classes form H-type pseudoknots upon PreQ₁ binding, each of which has distinct unusual features and modes …

Metallurgical And Corrosion Assessment Of Submerged Tanker S.S. Montebello, Dana Medlin, James D. Carr, Donald L. Johnson, David L. Conlin

Department of Chemistry: Faculty Publications

The Union Oil Tanker S.S. Montebello was torpedoed and sunk six miles (9.7 km) off the coast of Cambria, California by a Japanese submarine on December 23, 1941, two weeks after the attack on Pearl Harbor. With close proximity to the National Monterey Bay Marine Sanctuary, concern about possible crude oil contamination led to the most recent expedition to the site in October 2011. Assessment of the shell plate found that the average corrosion rate was very low and the structure will remain stable for many decades.

Advances In Chemical And Structural Characterization Of Concretion With Implications For Modeling Marine Corrosion, Donald L. Johnson, Robert J. Deangelis, Dana J. Medlin, James D. Carr, David L. Conlin

Department of Chemistry: Faculty Publications

The Weinsnumber model and concretion equivalent corrosion rate methodology were developed as potential minimum-impact, cost-effective techniques to determine corrosion damage on submerged steel structures. To apply the full potential of these technologies, a detailed chemical and structural characterization of the concretion (hard biofouling) that transforms into iron bearing minerals is required. The fractions of existing compounds and the quantitative chemistries are difficult to determine from x-ray diffraction. Environmental scanning electron microscopy was used to present chemical compositions by means of energy-dispersive spectroscopy (EDS). EDS demonstrates the chemical data in mapping format or in point or selected area chemistries. Selectedarea EDS …

Analogues Of (-)-Picropodophyllin, Synthesis And Uses Thereof, David B. Berkowitz, Sylvain Broussy

Department of Chemistry: Faculty Publications

Analogs of (-)-Picropodophyllin, synthesis thereof, and uses in pharmaceuticals as inhibitors of IGF1RK.

Ionic Liquid Extraction Unveils Previously Occluded Humicbound Iron In Peat Porewater, Timothy J. Veverica

Dissertations, Master's Theses and Master's Reports - Open

Extracellular iron reduction has been suggested as a candidate metabolic pathway that may explain a large proportion of carbon respiration in temperate peatlands. However, the o-phenanthroline colorimetric method commonly employed to quantitate iron and partition between redox species is known to be unreliable in the presence of humic and fulvic acids, both of which represent a considerable proportion of peatland dissolved organic matter. We propose ionic liquid extraction as a more accurate iron quantitation and redox speciation method in humic-rich peat porewater. We evaluated both o-phenanthroline and ionic liquid extraction in four distinct peatland systems spanning a gradient of physico-chemical …

Methods Development In Biological Mass Spectrometry: Application In Glycoproteomics, Sanja Trajkovic

Theses and Dissertations--Chemistry

Proteomics refers to global characterization of the full set of proteins present in a biological sample. Various analytical disciplines contribute to proteomics but mass spectrometry became method of choice for analysis of complex protein samples.

Mass spectrometry allows for high throughput analysis of the proteome but, moreover, it has the ability to acquire higher-order information such as post-translational modifications (PTM). Glycosylation is the most abundant PTM on eukaryotic proteins.

This dissertation will focus on method development for structural proteomics that will be utilized to explain the glycoproteome of obligate intracellular protozoan parasite Toxoplasma gondii as a model system.

Optimization of …

Applications Of Gas Chromatography/Mass Spectrometry And Capillary Electrophoresis For The Analysis Of Lignocellulosic Biomass Pretreatment, Dawn M. Kato

Theses and Dissertations--Chemistry

The focus of this dissertation centers on the development and applications of gas chromatography/mass spectrometry and capillary electrophoresis methodologies to quantify monomeric compositions of the β-O-4 linkages in lignin. Pretreatment is a required step in the utilization of lignocellulosic biomass for biofuels. Lignin is the target of pretreatment because it hinders the accessibility of enzymes and chemicals to cellulose. The effects of pretreatment are commonly assessed utilizing enzymatic saccharification and lignin assays. However, these techniques do not elucidate the effects of pretreatment on the monomeric make up of lignin.

The overarching hypothesis of this dissertation is that changes in individual …

Surface Complexation Of Monosubstituted Organoarsenicals On Hematite: Atr-Ftir Investigations, Md Abdus Sabur

Theses and Dissertations (Comprehensive)

Little is known about the surface chemistry of organoarsenic compounds with iron-containing materials commonly found in geosorbents and arsenic removal technologies. In this thesis, these organoarsenicals include aliphatic and aromatic arsenicals that historically have been used as herbicides, pesticides and in the poultry feed industry, respectively. Attenuated total internal reflectance Fourier transform infrared spectroscopy has been used to study the surface interactions of organoarsenicals at the molecular level under various environmentally-relevant conditions. Kinetic and thermodynamic parameters extracted from these molecular level experiments provide trends that are not observed in any published bulk experiments. Apparent initial rates of adsorption and desorption …

Infrared Vibrational Spectroscopy Analysis Of Selected Biomolecules, Busra Ergul

Theses and Dissertations

Fourier transform infrared (FTIR) spectroscopy is a useful tool to examine biological molecules for noninvasive measurements. This research has focused on the determination of concentrations of four important biomolecules, glucose, gluconic acid, hydrogen peroxide (H2O2), and dopamine by FTIR. It is crucial to determine blood glucose levels for diabetes diagnosis. H2O2 is an important biomolecule having implications in aging and aging related diseases. Gluconic acid is important in food and pharmaceutical industries, and dopamine plays a key role in brain activity. In this work, first, glucose, gluconic acid, and H2O2 in aqueous solutions have been studied by using FTIR. Standard …

Fluorination Of Aromatic Ring Systems, Stephen G. Dimagno

Department of Chemistry: Faculty Publications

This disclosure relates to reagents and methods useful in the synthesis of aryl fluorides, for example, in the preparation of ¹⁸F labeled radiotracers. The reagents and methods provided herein may be used to access a broad range of compounds, including aromatic compounds, heteroaromatic compounds, amino acids, nucleotides, and synthetic compounds.

Synthesis And Characterization Of Manganese Pyridazyl Complexes, Sana Shah

Masters Theses & Specialist Projects

Heterocyclic’s and their fused-ring derivatives have been of interest for their use in electronic materials due to their ease of production, synthetic versatility, and low cost compared to traditional inorganic materials like silicon. Pyridazines have been found to be useful in catalysis gas storage, polymeric sensors and biological mimetics. When a transition-metal is fused into a synthesized pyridazine, unique properties such as conductivity and optics are allowed. In this work, synthesized pyridazine complexes will be analyzed by mass spectroscopy, elemental analysis, nuclear magnetic resonance, imaging, x-ray crystallography, and infrared spectroscopy. We are interested in synthesizing organometallic pyridazines and manganese pyridazyl …

Synthesis And Structures Of New Three-Dimensional Copper Metal-Organic Frameworks, Nitin Kumar Pally

Masters Theses & Specialist Projects

Metal-organic frameworks (MOFs) are crystalline materials with metal ions covalently bonded to organic ligands. The ligands act as spacers often creating a porous structure with very high pore volume and surface area. MOFs are known for their robust structures, high porosity, and different chemical functionalities and are considered for applications in adsorptions, separations, catalysis and gas storage. This work focuses on the synthesis of new MOFs using copper compounds. Different types of carboxylate ligands were used for the synthesis. Two new copper-organic frameworks, [Cu₃(pyz)(btc)] (1), and [(Cu₃(btc))•xH₂O] (2) (btc= benzene-1,3,5-tricarboxylate, pyz= pyrazine) have been …

Phosphate Esters, Thiophosphate Esters And Metal Thiophosphates As Lubricant Additives, David W. Johnson, John E. Hils

Chemistry Faculty Publications

Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.

Electrochemical Reduction Of Aqueous Uranium, Jonathan M. Scaggs

Boise State University Theses and Dissertations

The electrochemical reduction of uranium in acidic aqueous environments with the express purpose of generating U(III) consistently is critically evaluated. Generating U(III) in an aqueous environment is difficult and extremely unstable and has historically been difficult to achieve and isolate for further investigation. The electrochemical cell, electrodes, supporting electrolytes, and pH’s are all reviewed and evaluated for the purpose of optimizing the systemic requirements to electrochemically generate U(III). Several new types of electrochemical cells to include two new spectroelectrochemical for UV-Vis and FT-Raman investigation were designed and tested for the purpose of analyzed the redox species of aqueous uranium generated …

Microfluidics Guided By Redox-Magnetohydrodynamics (Mhd) For Lab-On-A-Chip Applications, Vishal Sahore

Graduate Theses and Dissertations

Unique microfluidic control actuated by simply turning off and on microfabricated electrodes in a small-volume system was investigated for lab-on-a-chip applications. This was accomplished using a relatively new pumping technique of redox-magnetohydrodynamics (MHD), which as shown in this dissertation generated the important microfluidic features of flat flow profile and fluid circulation. MHD is driven by the body force, FB = j × B, which is the magnetic part of the Lorentz force equation, and its direction is given by the right hand rule. The ionic current density, j, was generated in an equimolar solution of potassium ferri/ferro cyanide by applying …

The Development And Applications Of Nmr Metabolomics Analysis Of Bacterial Metabolomes, Steven M. Halouska

Department of Chemistry: Dissertations, Theses, and Student Research

Metabolomics is a relatively new field that involves the study of metabolic responses that are occurring within a biological system. Metabolite profiles of an organism, tissue extract, and biofluids are important indicators to determine the physiological state of a biological profile. Comparison of such profiles from different phenotypes can be used to identify specific metabolic changes leading to the understanding of metabolic pathways, disease progression, drug toxicity and efficacy, and cellular responses to different intracellular and extracellular conditions. Metabolomics investigations often use sophisticated analytical techniques such as NMR spectroscopy to provide an unbiased and comprehensive approach to evaluate metabolic perturbation …

Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley

Master's Theses

Microalgae hold much promise as a feedstock in liquid biofuel production. Lipid content of microalgae cells range from 30-80% dry weight of biomass. It is projected that microalgae can produce between 1,000-6,500 gallons/acre/year of oil. Currently, production of industrial algae operates in open raceway ponds that use minimal capital and energy inputs to culture algae. Raceway ponds can also be used to grow microalgae from municipal waste streams. Although high biomass productivity can be achieved in these systems, there remains a large production gap between large volumes of biomass cultivation and high lipid content from microalgae cells. Low lipid content …