Chemistry Commons^™

Small Studies, Big Decisions: The Role Of Pilot/Feasibility Studies In Incremental Science And Premature Scale-Up Of Behavioral Interventions, Michael William Beets, Lauren Von Klinggraeff, Robert G. Weaver, Bridget Ryan Armstrong, Sarah Burkart

Faculty Publications

Background: Careful consideration and planning are required to establish “sufficient” evidence to ensure an investment in a larger, more well-powered behavioral intervention trial is worthwhile. In the behavioral sciences, this process typically occurs where smaller-scale studies inform larger-scale trials. Believing that one can do the same things and expect the same outcomes in a larger-scale trial that were done in a smaller-scale preliminary study (i.e., pilot/feasibility) is wishful thinking, yet common practice. Starting small makes sense, but small studies come with big decisions that can influence the usefulness of the evidence designed to inform decisions about moving forward with a …

Halogen Interactions In Halogenated Oxindoles: Crystallographic And Computational Investigations Of Intermolecular Interactions, Rodrigo Lemos Silva, Demetrio Da Silva Filho, Megan Moberg, Ted Pappenfus, Daron Janzen

Chemistry and Biochemistry Faculty Scholarship

X-ray structural determinations and computational studies were used to investigate halogen interactions in two halogenated oxindoles. Comparative analyses of the interaction energy and the interaction properties were carried out for Br...Br, C-H...Br, C-H...O and N-H...O interactions. Employing Møller–Plesset second-order perturbation theory (MP2) and density functional theory (DFT), the basis set superposition error (BSSE) corrected interaction energy (Eint(BSSE)) was determined using a supramolecular approach. The Eint(BSSE) results were compared with interaction energies obtained by Quantum Theory of Atoms in Molecules (QTAIM)-based methods. Reduced Density Gradient (RDG), QTAIM and Natural bond orbital (NBO) calculations provided insight into possible pathways for the intermolecular …

Emergence Of Non-Hexagonal Crystal Packing Of Deswollen And Deformed Ultra-Soft Microgels Under Osmotic Pressure Control, Molla R. Islam, Rachel Nguyen, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Highly solvent swollen poly(N-isopropylacrylamide-co-acrylic acid) microgels are synthesized without exogenous crosslinker, making them extremely soft and deformable. These ultralow crosslinked microgels (ULC) are incubated under controlled osmotic pressure to provide a slow (and presumably thermodynamically controlled) approach to higher packing densities. It is found that ULC microgels show stable colloidal packing over a very wide range of osmotic pressures and thus packing densities. Surprising observation of co-existence between hexagonal and square lattices is also made over the lower range of studied osmotic pressures, with microgels apparently changing shape from spheres to cubes in defects or grain boundaries. It is proposed …

Analysis Of The Electronic Effects And Reactivity Of Benzhydrols In The Formation Of Benzhydryl Ethers, Katherine Quesada, Daniel Chabeda, Jaeger Johnson, Alex Shore

The Yale Undergraduate Research Journal

Benzhydryl ethers were synthesized through the use of microwave irradiation in a proto-ionic liquid solvent. The resulting products were separated from the reaction mixture by vacuum filtration with a silica gel plug. The products were analyzed using GCMS and 1 H NMR techniques to identify and quantify products. Analysis of the resultant data indicated the syntheses of the desired benzhydryl products were successful for 4,4-dimethoxybenzhydrol (conversion: 83% (1-propyl ether), 11% (2-propyl ether), 11% (menthyl ether)) and 4,4-dimethylbenzhydrol (conversion to desired product: 100% (1-propyl ether), 100% (2-propyl ether), 26% (menthyl ether)). However, the syntheses were unsuccessful for reactant 4,4-difluorobenzhydrol and benzhydrol. …

Spectral Analysis Of A New Electronic Transition Of Platinum Fluoride, Ptf, Carol Welch

Undergraduate Research Symposium

The electronic landscape of platinum containing molecules has been the focus of numerous spectroscopic studies in recent years, because of the difficulty in describing electronic structure theoretically due to electronic correlations and relativistic effects. A collective effort by spectroscopitsts and theoreticians to investigate the diatomic molecule platinum fluoride, PtF, has included research such as developing potential energy diagrams and performing analyses on rotational transitions with microwave spectroscopy. One group observed electronic transitions of PtF using laser vaporization/reaction with jet free expansion and laser induced spectroscopy. A highly effective method for observing and analyzing electronic transitions of small, metal-containing molecules like …

Pressure-Induced Polymorphic Transformations Of Ethylenediamine Bisborane, Rongfeng Guan, Pan Wang, Yang Song, Viktor N. Staroverov

Chemistry Publications

Pressure-induced phase transitions of crystalline ethylenediamine bisborane (EDAB), a prospective hydrogen storage material, are investigated using vibrational spectroscopy, X-ray diffraction, evolutionary crystal structure prediction, and density functional theory. The results indicate that EDAB undergoes two transitions in the 0–17 GPa pressure range: the first one is near 1 GPa, from the orthorhombic ambient-pressure Pbca structure (phase I) to a monoclinic structure of P21/c symmetry (phase II); the second is near 7 GPa, from phase II to another P21/c structure (phase III). The latter coexists with phase II and remains the most stable form of EDAB up …

An Examination Of Factors Influencing Small Proton Chemical Shift Differences In Nitrogen-Substituted Monodeuterated Methyl Groups, Stuart J. Elliott, O. Maduka Ogba, Lynda J. Brown, Daniel J. O'Leary

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Monodeuterated methyl groups have previously been demonstrated to provide access to long-lived nuclear spin states. This is possible when the CH₂ D rotamers have sufficiently different populations and the local environment is chiral, which foments a non-negligible isotropic chemical shift difference between the two CH₂ D protons. In this article, the focus is on the N-CH₂ D group of N-CH₂ D-2-methylpiperidine and other suitable CH₂ D piperidine derivatives. We used a combined experimental and computational approach to investigate how rotameric symmetry breaking leads to a ¹H CH₂ D chemical shift …

Catechin And Other Catechol-Containing Secondary Metabolites: Bacterial Biotransformation And Regulation Of Carbohydrate Metabolism, Sara Knezevic, Asma Ghafoor, Samaneh Mehri, Ali Barazi, Maksymilian Dziura, John F. Trant, Christopher A. Dieni

Chemistry and Biochemistry Publications

Background: Catechol, 1,2-dihydroxybenzene, prepared through bacterial biotransformation from higher order polyphenols, has been proposed to regulate carbohydrate metabolism, especially in the context of type 2 diabetes. This review aims to contextualize this finding. It describes the bacterial biosynthesis of catechol both from glucose, and as a degradation product of higher order natural products through bacterial transformation. The review then considers the mechanism of action of glycemic-regulating catechol-containing materials and the complications arising from balancing their inherent activity with that of catechol, their common degradation product. It then enumerates potential dietary sources of catechin from common foods. Methods: Articles were found …

Utah - Perry Port Of Entry 2020, University Of Denver

FEAT Heavy-Duty Vehicle Measurements

Relevant Publications

Environmental Science & Technology publication.

Utah DEQ Final Report

College Of Natural Sciences Newsletter, September 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 9.

Page 1 Dean's Message
Page 2 Awards and Recognition
Page 3 Student Clubs in Natural Science
Page 4 Media Coverage of CNS
Page 5 Hobo Day Festivities
Page 6 Open PRAIRIE Data; Grants Awarded in CNS
Page 7 One Day for State Recap

Dissecting Monomer-Dimer Equilibrium Of An Rnase P Protein Provides Insight Into The Synergistic Flexibility Of 5’ Leader Pre-Trna Recognition, Danyun Zeng, Ainur Abzhanova, Benjamin P. Brown, Nicholas J. Reiter

Chemistry Faculty Research and Publications

Ribonuclease P (RNase P) is a universal RNA-protein endonuclease that catalyzes 5’ precursor-tRNA (ptRNA) processing. The RNase P RNA plays the catalytic role in ptRNA processing; however, the RNase P protein is required for catalysis in vivo and interacts with the 5’ leader sequence. A single P RNA and a P protein form the functional RNase P holoenzyme yet dimeric forms of bacterial RNase P can interact with non-tRNA substrates and influence bacterial cell growth. Oligomeric forms of the P protein can also occur in vitro and occlude the 5’ leader ptRNA binding interface, presenting a challenge in accurately defining …

Electronic Structures And Spectroscopic Signatures Of Diiron Intermediates Generated By O2 Activation Of Nonheme Iron(Ii)–Thiolate Complexes, Danushka M. Ekanayake, Dao Pham, Andrew L. Probst, Joshua R. Miller, Cordina V. Popescu, Adam T. Fiedler

Chemistry Faculty Research and Publications

The activation of O₂ at thiolate–ligated iron(II) sites is essential to the function of numerous metalloenzymes and synthetic catalysts. Iron–thiolate bonds in the active sites of nonheme iron enzymes arise from either coordination of an endogenous cysteinate residue or binding of a deprotonated thiol-containing substrate. Examples of the latter include sulfoxide synthases, such as EgtB and OvoA, that utilize O₂ to catalyze tandem S–C bond formation and S-oxygenation steps in thiohistidine biosyntheses. We recently reported the preparation of two mononuclear nonheme iron–thiolate complexes (1 and 2) that serve as structural active-site models of substrate-bound EgtB …

Bioaccessibility And Reactivity Of Alloy Powders Used In Powder Bed Fusion Additive Manufacturing, Yolanda S. Hedberg

Chemistry Publications

Exposure to metal particles via the inhalation route unavoidably takes place at occupational settings during additive manufacturing of metals and alloys. This calls for investigations on possible adverse health effects. This study focuses on virgin and reused powders of three iron- and nickel-based alloy powders (316L, IN718, 18Ni300) widely used in additive manufacturing, and dust powder of 18Ni300 generated during laser melting. Investigations were performed from a physico-chemical and toxicological perspective assessing their bioaccessibility in artificial lysosomal fluid (ALF, simulating lung exposure to respirable particles), corrosion behavior, surface morphology and composition, microstructure, hydrodynamic size distribution in ALF, and in-vitro toxicity …

Mechanically Transduced Immunosorbent Assay To Measure Protein-Protein Interactions, Christopher J. Petell, Kathyrn Randene, Michael Pappas, Diego Sandoval, Brian Dstrahl, Joseph S. Harrison, Joshua P. Steimel

College of the Pacific Faculty Articles

Measuring protein-protein interaction (PPI) affinities is fundamental to biochemistry. Yet, conventional methods rely upon the law of mass action and cannot measure many PPIs due to a scarcity of reagents and limitations in the measurable affinity ranges. Here, we present a novel technique that leverages the fundamental concept of friction to produce a mechanical signal that correlates to binding potential. The mechanically transduced immunosorbent (METRIS) assay utilizes rolling magnetic probes to measure PPI interaction affinities. METRIS measures the translational displacement of protein-coated particles on a protein-functionalized substrate. The translational displacement scales with the effective friction induced by a PPI, thus …

Laboratory Capabilities, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Energy & Environmental Research Center’s (EERC’s) laboratory capabilities including reservoir characterization, organic geochemistry, fluid sampling, and material analysis. A list of publications and laboratory information is also included.

Behavioral Modulation Of Supramolecular Assemblies Via Covalent And Non-Covalent Interfacial Transformations, Ann Fernandez

Doctoral Dissertations

There are several molecular level mechanisms at the origin of biological functions that serve as inspiration for the development of the “next generation” of materials that display adaptive and interactive properties. However, it will take time for synthetic materials to approach the level of complexity, robustness, and adaptability of biological systems. Although there are switchable platforms that respond via sensitized molecular components, there are currently no examples of materials that truly possess the type of autonomous behavior seen in biological systems. Even though these concepts are common in living organisms, their translation into a synthetic platform remains challenging to this …

Manipulating The Aliovalent Magnetic Dopants In Ti(Iv)-Based Oxide Nanocrystals, Muhammad Abdullah

Doctoral Dissertations

The intentional incorporation of impurities or dopants in semiconductors is fundamental to manipulate the properties that render them useful for spintronics, photocatalysis, and optoelectronics. One long-standing challenge in integrating the doped semiconductors in various applications is the design of materials with controlled individual dopant properties such as dopants speciation, valence state, and spin dynamics. Despite several elegant studies to circumvent these material challenges, the quest for new materials with tunable dopant properties to address the theoretical and experimental understanding continues. In this work, we combine synthetic chemistry and various spectroscopies to study a class of materials possessing both substitutional magnetic …

Design Of Resposive Oligomeric And Polymeric Interfaces For Sensing And Controlled Release Applications, . Manisha

Doctoral Dissertations

Nature has designed magnificent responsive systems by constructing several interacting molecular level networks for the recognition and propagation of chemical and biochemical information. One of the eminent characteristics of these systems is their capability to quickly transduce molecular scale recognition events into macroscopic or visually observable responses. Inspired by these systems present in nature, we became interested in developing artificial responsive systems with similar capabilities. This dissertation will feature four such systems that employ amphiphilic oligomers and polymers which were chosen as the scaffolds because of their high thermodynamic stability, low critical aggregation concentrations, convenient handles to incorporate functional group …

Instrumentation For Routine Analysis Of Acrylamide In French Fries: Assessing Limitations For Adoption, Mark M. Skinner, Jared T. Seale, Maranda S. Cantrell, Joseph M. Collins, Matthew W. Turner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The purpose of this experimental review was to detect acrylamide in French fries using methods most adaptable to the food process industry for quality control assessment of products. French fries were prepared at different cook times using the same fryer oil over a five-day period to assess the influence of oil degradation and monitor trends in acrylamide formation. Acrylamide detection was performed using LC-MS, GC-MS and FT-NIR. The low levels of acrylamide produced during frying, low molecular weight of the analyte, and complexity of the potato matrix make routine acrylamide measurement challenging in a well-outfitted analytical lab with trained personnel. …

Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski

Dissertations, Theses, and Capstone Projects

Recent genomic studies of microbiomes have revealed an overwhelming number of biosynthetic genes of unknown function. Most of these “cryptic” biosynthetic genes are not expressed in laboratory monocultures of individual microbes. Thus, there remains tremendous untapped potential for natural products discovery. Here we employ mixed microbial culture (MMC) as a simple yet powerful approach to awaken cryptic biosynthetic gene clusters. Our preliminary studies demonstrated that arrays of metabolites could be induced in MMCs upon environmental cues, such as surface adhesion. Using this system, we have screened, identified, and isolated bioactive bacterial metabolites, which were characterized structurally and biologically. Of the …