Other Chemistry Commons^™

Majestic - Prappe Metals Data, Brian Majestic

Chemistry and Biochemistry: Data Sets

No abstract provided.

Polarization-Independent Metasurface Lens Based On Binary Phase Fresnel Zone Plate, Jonathan Baine, Jing Tang, Xing Li

Chemistry Department: Faculty Publications

Based on the binary phase Fresnel zone plate (FZP), a polarization-independent metasurface lens that is able to focus incident light with any polarization state, including circular, linear, and elliptical polarizations, has been proposed and investigated. We demonstrate that the metasurface lens consisting of metal subwavelength slits can operate in a wide bandwidth in the visible range, and has a higher focusing efficiency than that of an amplitude FZP lens without phase modulation. A multi-focus FZP metasurface lens has also been designed and investigated. The proposed lens can provide potential applications in integrated nanophotonic devices without polarization limitations.

Constructing Stable And Potentially High-Performance Hybrid Organic-Inorganic Perovskites With “Unstable” Cations, Qing Yang, Menghao Wu, Xiao Cheng Zeng

Chemistry Department: Faculty Publications

A new family of functional hybrid organic-inorganic perovskites (HOIPs) is theoretically designed based on the following chemical+ insights: when a proton is adhered to molecules like water or ethanol, the newly formed larger-sized cations (e.g., H5O2 ,++ C2H5OH2 , and CH3SH ) entail low electron affinities mimicking superalkalis; they are conjugated acids of weak bases that cannot survive in solution, while their chemistry behavior in the HOIP frameworks, however, may be markedly different due to greatly enhanced cohesive energies of the proton, which facilitate the formation of new HOIPs. First-principles computations show that the putative formation reactions for these newly …

Lew,1wr1 Rat Shows An Increased Risk Of Developing Malignant Forms Of Nafld, Luis Mercado

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Synthesis Of Unsymmetrical Bidentate Ligands From Secondary Phosphine Oxides, Malachy J. Brink, Ryan Anderson

Student Research, Papers, and Creative Works

Stereochemistry is a key component in the field of asymmetric catalysis. The properties of a molecule can be drastically changed with the change of one stereocenter. Typically, chirality is imparted to a metal by the ligand. "Chiral-at-metal" compounds are unique because the metal complex is chiral, but the ligands are not. Phosphine ligands are notoriously difficult to work with (pyrophoric, toxic, prone to oxidation). The goal of this research was to prepare unsymmetrical bidentate ligands using secondary phosphine oxides, which are air-stable and easy to handle on the benchtop.

Methods Ofmaking And Using Lignin Derivatives, Mark Alan Helle, Chin Li Cheung

Chemistry Department: Faculty Publications

Materials and methods for preparing reactive lignin and for preparing a bio-based adhesive are described herein.

Nanotoxicity Of Zrs3 Probed In A Bioluminescence Test On E. Coli Bacteria: The Effect Of Evolving H2s, Olga Zakharova, Alexander Gusev, Jehad Abourahma, Nataliia S. Vorobeva, Dmitry V. Sokolov, Dmitry S. Muratov, Denis V. Kuznetsov, Alexander Sinitskii

Chemistry Department: Faculty Publications

Materials from a large family of transition metal trichalcogenides (TMTCs) attract considerable attention because of their potential applications in electronics, optoelectronics and energy storage, but information on their toxicity is lacking. In this study, we investigated the toxicity of ZrS3, a prominent TMTC material, toward photoluminescent E. coli bacteria in a bioluminescence test. We found that freshly prepared ZrS3 suspensions in physiological saline solution with concentrations as high as 1 g/L did not exhibit any toxic effects on the bacteria. However, ZrS3 suspensions that were stored for 24 h prior to the bioluminescence tests were very toxic to the bacteria …

Agbis2 As A Low-Cost And Eco-Friendly All-Inorganic Photovoltaic Material: Nanoscale Morphology– Property Relationship†, Ming-Gang Ju, Jun Dai, Liang Ma, Yuanyuan Zhou, Xiao Cheng Zeng

Chemistry Department: Faculty Publications

Solar cells made of low-cost solution-processed all-inorganic materials are a promising alternative to conventional solar cells made of high-temperature processed inorganic materials, especially because many high-temperature processed inorganic materials contain toxic element(s) such as lead or cadmium (e.g., CsPbI₃ perovskite, PbS, CdTe and CdS(Se)). AgBiS₂ nanocrystals, consisting of earth-abundant elements but without lead and cadmium, have already emerged as a promising candidate in highperformance solar cells. However, the nanoscale morphology–optoelectronic property relationship for AgBiS₂ nanocrystals is still largely unknown. Herein, we investigate the electronic properties of various AgBiS₂ nanocrystals by using first-principles computation. We show that …

Instrument And Application Development In Saturation Recovery And Rapid Scan Electron Paramagnetic Resonance, Joseph E. Mcpeak

Electronic Theses and Dissertations

Enhanced signal sensitivity by the use of Rapid Scan (RS) electron paramagnetic resonance (EPR), a technique that allows for much faster magnetic field scans than traditional field-swept techniques, has facilitated improved data acquisition for many types of samples. For example, irradiated fingernails for radiation dosimetry have been studied using RS-EPR, which resulted in substantial decreases in detection limits. Samarium-mediated reduction mechanisms in organic synthesis have been investigated by RS-EPR providing evidence for a radical intermediate. Spectra of organic radicals exhibiting both narrow lines and closely spaced hyperfine interactions have been recorded via RS-EPR. Well-resolved spectra can be recorded at a …

Cu(Ii) Phenanthroline-Phenazine Complexes Dysregulate Mitochondrial Function And Stimulate Apoptosis, Garret Rochford, Zara Molphy, Kevin Kavanagh, Malachy Mccann, Michael Devereux, Andrew Kellett, Orla L. Howe

Articles

Herein we report an in-depth study on the cytotoxic mechanism of action of four developmental cytotoxic copper(II) complexes: [Cu(phen)2]2+ (Cu-Phen); [Cu(DPQ)(Phen)]2+ (Cu-DPQ-Phen); [Cu(DPPZ)(Phen)]2+; and [Cu(DPPN)(Phen)]2+ (where Phen = 1,10-phenanthroline, DPQ = dipyrido[3,2-f:20,30-h]quinoxaline, DPPZ = dipyrido[3,2-a:20,30-c]phenazine, and DPPN = benzo[i]dipyrido[3,2-a:20,30-c]phenazine). This complex class is known for its DNA intercalative properties and recent evidence—derived from an in vivo proteomic study—supports the potential targeting of mitochondrial function. Therefore, we focused on mitochondrial-mediated apoptosis related to cytotoxic activity and the potential impact these agents have on mitochondrial function. The Cu(II) complexes demonstrated superior activity regardless of aromatic extension within the phenazine ligand to the …

Synthesis And Evaluation Of Nebraska Red Derivatives For Protein Labeling Studies, Lauren Lesiak

Honors Theses

G protein-coupled receptors (GPCRs) play a vital role in cell signaling, and imaging the internalization of these proteins will allow for better understand of protein trafficking within the cell, as well as identification of potential drug targets. However, there is a need for further development of fluorescent protein labels that are able to effectively monitor GPCR internalization in the near-infrared (NIR) range. We recently described a series of NIR fluorophores in which a phosphinate functionality is inserted at the bridging position of the xanthene scaffold, called the Nebraska Red (NR) dye series. These dyes are attractive reagents for the imaging …

Carbon Oxidation State In Microbial Polar Lipids Suggests Adaptation To Hot Spring Temperature And Redox Gradients, Grayson M. Boyer, Florence Schubotz, Roger E. Summons, Jade Woods, Everett L. Shock

Chemistry Department: Faculty Publications

The influence of oxidation-reduction (redox) potential on the expression of biomolecules is a topic of ongoing exploration in geobiology. In this study, we investigate the novel possibility that structures and compositions of lipids produced by microbial communities are sensitive to environmental redox conditions. We extracted lipids from microbial biomass collected along the thermal and redox gradients of four alkaline hot springs in Yellowstone National Park (YNP) and investigated patterns in the average oxidation state of carbon (Z_C), a metric calculated from the chemical formulae of lipid structures. Carbon in intact polar lipids (IPLs) and their alkyl chains becomes …

Rapid And Accurate Determination Of Atomistic Rna Dynamic Ensemble Models Using Nmr And Structure Prediction, Honglue Shi, Atul Rangadurai, Hala Abou Assi, Rohit Roy, David A. Case, Daniel Herschlag, Joseph D. Yesselman, Hashim M. Al-Hashimi

Chemistry Department: Faculty Publications

Biomolecules form dynamic ensembles of many inter-converting conformations which are key for understanding how they fold and function. However, determining ensembles is challenging because the information required to specify atomic structures for thousands of conformations far exceeds that of experimental measurements. We addressed this data gap and dramatically simplified and accelerated RNA ensemble determination by using structure prediction tools that leverage the growing database of RNA structures to generate a con- formation library. Refinement of this library with NMR residual dipolar couplings provided an atomistic ensemble model for HIV-1 TAR, and the model accuracy was independently sup- ported by comparisons …

A Luminescence-Based System For Identification Of Genetically Encodable Inhibitors Of Protein Aggregation, Travis J. Nelson, Shuo Liang, Cliff I. Stains

Chemistry Department: Faculty Publications

Molecules that disrupt protein aggregation represent potential tool compounds for the investigation of numerous human disease states. However, the identification of small molecules capable of disrupting protein aggregation has proven challenging. Larger biomolecules such as antibodies and proteins are promising alternatives due to their increased size. Despite the promise of protein-based inhibitors, generalizable assays are needed to more readily identify proteins capable of inhibiting aggregation. Herein, we utilize our previously reported self- assembling NanoLuc luciferase fragments to engineer a platform in which both detection reagents are expressed from the same plasmid, enabling facile co-transformation with a genetically encodable inhibitor. This …

A Click-Based Modular Approach To Introduction Of Peroxides Onto Molecules And Nanostructures, Alissa Horn, Patrick H. Dussault

Chemistry Department: Faculty Publications

Copper-promoted azide/alkyne cycloadditions (CuAAC) are explored as a tool for modular introduction of peroxides onto molecules and nanomaterials. Dialkyl peroxide-substituted alkynes undergo Cu(I)- promoted reaction with azides in either organic or biphasic media to furnish peroxide-substituted 1,2,3- triazoles. Heterolytic fragmentation of the peroxide to an aldehyde, a side reaction that appears to be related to the formation of the triazole, can be suppressed by use of excess alkyne, the presence of triethylsilane, or by use of iodoalkyne substrates. Complementary reactions of simple alkynes with azidosubstituted peroxides are much less efficient. Click reactions of alkynyl peroxyacetals are also reported; reductive fragmentation …

Improving The Value Of The Coconut With Biotechnology, Fabian M. Dayrit, Quang Nguyen

Chemistry Faculty Publications

The fruit of the coconut tree is perhaps the most useful plant resource in the tropics. All parts of the coconut fruit have traditional uses that have been developed commercially in recent times (Foale 2003, Dayrit and Dayrit 2013). Due to its widespread household use, trade and industry statistics on coconut products reflect only part of the actual importance of the coconut. Today, coconut-based products have gone beyond the tropics and are consumed in many temperate countries and global regions such as Australia, China, Europe, North America, and the Middle East (Costello 2018). Coconut milk is the basic ingredient of …

A Comparative Study Of Drug Affinities Determined By Thermofluor And Kinetic Analysis, Oruba Shatnawi

Theses, Dissertations and Culminating Projects

Determining the binding affinity and potency in vitro is one of the significant steps that can give a clue for a new candidate drug during the drug discovery process. Thermofluor is a method used in measuring binding affinity (Kd) of protein-ligands interaction through determining the change in thermal denaturation temperature of protein using real time PCR (RT-PCR). Kinetic analysis assay is used to screen a library of compounds to calculate their potencies (IC50) and inhibition constants (Ki) and it can be performed by spectrophotometer technique. In this study, we used bovine carbonic anhydrase II (BCA II) enzyme, and four of …

The Role Of Influenza Infection On Cell Metabolism, Megha Mokkapati

Williams Honors College, Honors Research Projects

In this particular study global metabolomics LCMS data was analyzed to determine the effect of influenza infection on host metabolic processes. Specifically, wild-type male and female mouse lung samples from mice infected with PR8 (H1N1) or both PR8 and a reinfection of X31 (H3N2) were analyzed. The LC/MS(liquid chromatography-mass spectrometry) based global metabolomics will be performed on the samples using hydrophilic interaction liquid chromatography to separate polar analytes from the tissues (Dettmer, Aronov, 2007). Metabolites impacted by influenza infection in all samples will be analyzed to compare male and female mice, as well as differences between PR8 infection and X31 …

Ozone And Reactive Oxidized Nitrogen Chemistry In The Northeast U.S, Matthew Ninneman

Legacy Theses & Dissertations (2009 - 2024)

Ongoing reductions in oxides of nitrogen concentrations ([NOx] = nitric oxide ([NO]) + nitrogen dioxide ([NO2])) throughout the continental United States (U.S.) have important implications for tropospheric ozone (O3) and reactive oxidized nitrogen chemistry (NOy ≈ NOx + nitric acid (HNO3) + particle nitrate (pNO3) + peroxy nitrates (PNs) + alkyl nitrates (ANs)). Specifically, decreasing [NOx] concentrations have likely (1) increased the sensitivity of O3 to the [NOx] level, and (2) affected NOy speciation and partitioning. An understanding of the impacts of continued [NOx] reductions is needed to inform current and future air pollution control strategies, especially since the National …

Antifungal Defense Molecules From Bacterial Symbionts Of North American Trachymyrmex Ants, Georgia Scherer

CMC Senior Theses

Defensive symbioses, in which microbes provide molecular defenses for an animal host, hold great potential as untapped sources of therapeutically useful antibiotics. Fungus-growing ants use antifungal defenses from bacterial symbionts to suppress pathogenic fungi in their nests. Preliminary chemical investigations of symbiotic bacteria from this large family of ants have uncovered novel antifungal molecules with therapeutic potential, such as dentigerumycin and selvamicin.

In this study, the bacterial symbionts of North American Trachymyrmex fungus-growing ants are investigated for antifungal molecules. Plate-based bioassays using ecologically-relevant fungal pathogens confirmed that these bacteria have antifungal activity. In order to purify and identify the antifungal …