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2021

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Full-Text Articles in Physical Sciences and Mathematics

Exploring The Relationships Among Stoichiometric Coefficients, Number Of Transferred Electrons, Mean Oxidation Number Of Carbons, And Oxidative Ratio In Organic Combustion Reactions, Pong Kau Yuen, Cheng Man Diana Lau Dec 2021

Exploring The Relationships Among Stoichiometric Coefficients, Number Of Transferred Electrons, Mean Oxidation Number Of Carbons, And Oxidative Ratio In Organic Combustion Reactions, Pong Kau Yuen, Cheng Man Diana Lau

Faculty Publications

Combustion reactions, stoichiometry, and redox reactions are some of the basic contents in chemistry curriculum. Although the counting of transferred electrons is critical in redox reactions, assigning mean oxidation number of organic carbons (ONc) is not always easy. Even though the relationship between the oxidative ratio (OR) and ONc is known, the relationship between the number of transferred electrons (Te−) and OR has not been thoroughly studied. The H-atom method has already been developed to balance and deduct organic combustion reactions. It can be used further to help establish the relationships among the stoichiometric coefficients (SC), the number of transferred …


A Nanoscale Shape-Discovery Framework Supporting Systematic Investigations Of Shape-Dependent Biological Effects And Immunomodulation, Wei Zhang, Hender Lopez, Luca Boselli, Paolo Bigini, André Perez-Potti, Zengchun Xie, Valentina Castagnola, Qi Cai, Camila P. Silveira, Joao M. De Araujo, Laura Talamini, Nicolò Panini, Giuseppe Ristagno, Martina B. Violatto, Stéphanie Devineau, Marco P. Monopoli, Mario Salmona, Valeria A. Giannone, Sandra Lara, Kenneth A. Dawson, Yan Yan Dec 2021

A Nanoscale Shape-Discovery Framework Supporting Systematic Investigations Of Shape-Dependent Biological Effects And Immunomodulation, Wei Zhang, Hender Lopez, Luca Boselli, Paolo Bigini, André Perez-Potti, Zengchun Xie, Valentina Castagnola, Qi Cai, Camila P. Silveira, Joao M. De Araujo, Laura Talamini, Nicolò Panini, Giuseppe Ristagno, Martina B. Violatto, Stéphanie Devineau, Marco P. Monopoli, Mario Salmona, Valeria A. Giannone, Sandra Lara, Kenneth A. Dawson, Yan Yan

Articles

Since it is now possible to make, in a controlled fashion, an almost unlimited variety of nanostructure shapes, it is of increasing interest to understand the forms of biological control that nanoscale shape allows. However, a priori rational investigation of such a vast universe of shapes appears to present intractable fundamental and practical challenges. This has limited the useful systematic investigation of their biological interactions and the development of innovative nanoscale shape-dependent therapies. Here, we introduce a concept of biologically relevant inductive nanoscale shape discovery and evaluation that is ideally suited to, and will ultimately become, a vehicle for machine …


Splashing Of Large Helium Nanodroplets Upon Surface Collisions, Paul Martini, Simon Albertini, Felix Laimer, Miriam Meyer, Michael Gatchell, Olof E. Echt, Fabio Zappa, Paul Scheier Dec 2021

Splashing Of Large Helium Nanodroplets Upon Surface Collisions, Paul Martini, Simon Albertini, Felix Laimer, Miriam Meyer, Michael Gatchell, Olof E. Echt, Fabio Zappa, Paul Scheier

Faculty Publications

In the present work we observe that helium nanodroplets colliding with surfaces can exhibit splashing in a way that is analogous to classical liquids. We use transmission electron microscopy and mass spectrometry to demonstrate that neutral and ionic dopants embedded in the droplets are efficiently backscattered in such events. High abundances of weakly bound He-tagged ions of both polarities indicate a gentle extraction mechanism of these ions from the droplets upon collision with a solid surface. This backscattering process is observed for dopant particles with masses up to 400 kilodaltons, indicating an unexpected mechanism that effectively lowers deposition rates of …


Sharing The Salt Bowl: Counterion Identity Drives N-Alkyl Resorcinarene Affinity For Pyrophosphate In Water, Kwaku Twum, Seyed Iraj Sadraei, Jordan Feder, S. Maryamdokht Taimoory, Kari Rissanen, John F. Trant, Ngong Kodiah Beyeh Dec 2021

Sharing The Salt Bowl: Counterion Identity Drives N-Alkyl Resorcinarene Affinity For Pyrophosphate In Water, Kwaku Twum, Seyed Iraj Sadraei, Jordan Feder, S. Maryamdokht Taimoory, Kari Rissanen, John F. Trant, Ngong Kodiah Beyeh

Chemistry and Biochemistry Publications

N-Alkyl ammonium resorcinarene chloride receptors, NARX4, have been shown to act as high-sensitivity detectors of pyrophosphate (PPi), a biomarker of disease, in aqueous media through the chloride-to-PPi exchange [NAR(Cl)4 to NARPPi]. The nature of the anion of the macrocyclic NARX4 (X = Cl−, Br−, triflate OTf−) receptor greatly influences the PPi-affinity in aqueous media. The binding affinity for [NAR (Cl)4] is 3.61 × 105 M−1, while the NAR (Br)4 and NAR (OTf)4 show stronger binding of 5.30 × 105 M−1, and 6.10 × 105 M−1, respectively. The effects of upper rim ammonium cation, –N+H2R substituents (R = 3-hydroxypropyl, cyclohexyl, …


High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig Dec 2021

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …


Leveraging The 1,3-Azadiene-Anhydride Reaction For The Synthesis Of Functionalized Piperidines Bearing Up To Five Contiguous Stereocenters, Jorge Garcia, Jane Eichwald, Jayme Zesiger, Timothy K. Beng Dec 2021

Leveraging The 1,3-Azadiene-Anhydride Reaction For The Synthesis Of Functionalized Piperidines Bearing Up To Five Contiguous Stereocenters, Jorge Garcia, Jane Eichwald, Jayme Zesiger, Timothy K. Beng

Student Published Works

A modular and scalable strategy, which remodels 3-methylglutaric anhydride to 2-oxopiperidines bearing at least three contiguous stereocenters is described. The approach relies on the chemoselective and stereocontrolled annulation of 1,3-azadienes with the anhydride component. The resulting acid-tethered allylic 2-oxopiperidines are then engaged in several selective fragment growth processes, including catalytic denitrative alkenylation, halolactonization, and Vilsmeier–Haack functionalization.


Mansouramycins E–G, Cytotoxic Isoquinolinequinones From Marine Streptomycetes, Mohamed Shaaban, Khaled A. Shaaban, Gerhard Kelter, Heinz Herbert Fiebig, Hartmut Laatsch Dec 2021

Mansouramycins E–G, Cytotoxic Isoquinolinequinones From Marine Streptomycetes, Mohamed Shaaban, Khaled A. Shaaban, Gerhard Kelter, Heinz Herbert Fiebig, Hartmut Laatsch

Center for Pharmaceutical Research and Innovation Faculty Publications

Chemical investigation of the ethyl acetate extract from the marine-derived Streptomyces sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E–G (1a–3a), in addition to the previously reported mansouramycins A (5) and D (6). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds. Cytotoxicity profiling of the mansouramycins in a panel of up to 36 tumor cell lines indicated a significant cytotoxicity and good tumor selectivity for mansouramycin F (2a), while the activity profile of E ( …


Reaction Of Alkynyl- And Alkenyltrifluoroborates With Propargyldicobalt Cations: Alkynylation, Alkenylation, And Cyclopropanation Product Pathways, Brent St Onge, S. Maryamdokht Taimoory, Jeffrey Battersby, John F. Trant, James R. Green Dec 2021

Reaction Of Alkynyl- And Alkenyltrifluoroborates With Propargyldicobalt Cations: Alkynylation, Alkenylation, And Cyclopropanation Product Pathways, Brent St Onge, S. Maryamdokht Taimoory, Jeffrey Battersby, John F. Trant, James R. Green

Chemistry and Biochemistry Publications

The Lewis acid-mediated Nicholas reactions of propargyl acetate–Co2(CO)6 complexes with a series of potassium alkynyltrifluoroborates and potassium alkenyltrifluoroborates are described. Alkynyltrifluoroborates directly alkynylate the intermediate propargyldicobalt cations. In contrast, alkenyltrifluoroborates proceed through one of the three modes of dominant reactivity: C-2-substituted alkenyltrifluorobrates directly alkenylate, predominantly with the retention of stereochemistry. C-1-substituted alkenyltrifluoroborates alkenylate at C-2. Potassium vinyltrifluoroborate incorporates a cyclopropane at the site propargyl to alkynedicobalt. Computational analysis of these systems explains the differential modes of reactivity of alkenyltrifluoroborates and outlines the probable mechanisms for the formation of each product.


Protocol For Fabricating Electroless Nickel Immersion Gold Strain Sensors On Nitrile Butadiene Rubber Gloves For Wearable Electronics, Sara S. Mechael, Yunyun Wu, Yiting Chen, Tricia Breen Carmichael Dec 2021

Protocol For Fabricating Electroless Nickel Immersion Gold Strain Sensors On Nitrile Butadiene Rubber Gloves For Wearable Electronics, Sara S. Mechael, Yunyun Wu, Yiting Chen, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

This protocol describes the fabrication of patterned conductive gold films on nitrile butadiene rubber (NBR) gloves for wearable strain sensors using electroless nickel immersion gold (ENIG) plating, a solution-based metallization technique. The resulting NBR/ENIG films are strain sensitive; resistance measurements of a patterned sensing array can be used to map human hand motions. This protocol also describes challenges related to the ENIG process and troubleshooting steps to achieve conformal gold films for strain sensing over a large working range. For complete details on the use and execution of this protocol, please refer to Mechael et al. (2021).


Characterization Of Landfill Leachate For Enhanced Metal Recovery, Hanna Fulford, Amisha Shah, Inez Hua, Nadezhda Zyaykina, Lori Hoagland, Alejandro Rodriguez Sanchez, Umut Bicim Dec 2021

Characterization Of Landfill Leachate For Enhanced Metal Recovery, Hanna Fulford, Amisha Shah, Inez Hua, Nadezhda Zyaykina, Lori Hoagland, Alejandro Rodriguez Sanchez, Umut Bicim

Discovery Undergraduate Interdisciplinary Research Internship

Landfills contain a trove of valuable materials, such as critical, precious, and rare earth metals, that are integral to the United State’s economy and national security. The leachate that filters through landfills picks up these materials, which allows for the possibility of recovery. For this research, samples will be analyzed from landfills throughout the Midwestern United States to provide a baseline on water quality constituents, elements present, and microbial activity. Preliminary data for this study was acquired by analyzing samples of landfill leachate from a landfill in northern Indiana. pH readings indicate that the leachate is slightly basic. It also …


Modifying The Aspect Survey To Support The Validity Of Student Perception Data From Different Active Learning Environments, Nicole Naibert, Erin E. Shortlidge, Jack Barbera Dec 2021

Modifying The Aspect Survey To Support The Validity Of Student Perception Data From Different Active Learning Environments, Nicole Naibert, Erin E. Shortlidge, Jack Barbera

Chemistry Faculty Publications and Presentations

Measuring students’ perceptions of active learning activities may provide valuable insight into their engagement and subsequent performance outcomes. A recently published measure, the Assessing Student Engagement in Class Tool (ASPECT), was developed to assess student perceptions of various active learning environments. As such, we sought to use this measure in our courses to assess the students’ perceptions of different active learning environments. Initial results analyzed with confirmatory factor analysis (CFA) indicated that the ASPECT did not function as expected in our active learning environments. Therefore, before administration within an introductory biology course that incorporated two types of active learning strategies, …


Visualizing Phytochemical-Protein Interaction Networks: Momordica Charantia And Cancer, Yumi L. Briones, Alexander T. Young, Fabian M. Dayrit, Armando Jerome De Jesus, Nina Rosario L. Rojas Dec 2021

Visualizing Phytochemical-Protein Interaction Networks: Momordica Charantia And Cancer, Yumi L. Briones, Alexander T. Young, Fabian M. Dayrit, Armando Jerome De Jesus, Nina Rosario L. Rojas

Chemistry Faculty Publications

The in silico study of medicinal plants is a rapidly growing field. Techniques such as reverse screening and network pharmacology are used to study the complex cellular action of medicinal plants against disease. However, it is difficult to produce a meaningful visualization of phytochemical-protein interactions (PCPIs) in the cell. This study introduces a novel workflow combining various tools to visualize a PCPI network for a medicinal plant against a disease. The five steps are 1) phytochemical compilation, 2) reverse screening, 3) network building, 4) network visualization, and 5) evaluation. The output is a PCPI network that encodes multiple dimensions of …


Comparative Toxicity, Phytochemistry, And Use Of 53 Philippine Medicinal Plants, Lydia M. Clemen-Pascual, Rene Angelo S. Macahig, Nina Rosario L. Rojas Dec 2021

Comparative Toxicity, Phytochemistry, And Use Of 53 Philippine Medicinal Plants, Lydia M. Clemen-Pascual, Rene Angelo S. Macahig, Nina Rosario L. Rojas

Chemistry Faculty Publications

The study compares the toxicity of 53 selected medicinal plants commonly used in the Philippines to treat various diseases. It uses as a benchmark Vitex negundo L., which was approved by the Philippine Food and Drug Administration as an herbal drug for cough and asthma after passing clinical trials for safety and efficacy. The methods were chosen for their simplicity and accessibility even for resource-limited laboratories. Extracts (95 % ethanol) of the medicinal parts of the plants were (1) chemically profiled using qualitative phytochemical tests that detect the presence of key classes of bioactive compounds; and (2) evaluated for toxicity …


Developing Techniques For The Identification Of Non-Canonical Rna Pairing And Analysis Of Lc-Ms Datasets, Christopher Jurich Dec 2021

Developing Techniques For The Identification Of Non-Canonical Rna Pairing And Analysis Of Lc-Ms Datasets, Christopher Jurich

Department of Chemistry: Dissertations, Theses, and Student Research

Non-canonical pairing dynamics in ribonucleic acid (RNA) structureand statistical analysis of metabolomics liquid chromatography mass spectrometry (LC-MS) datasets are two difficult problems that stand as open challenges.

RNA folding algorithms are used across a variety of disciplines to predict structures when experimental elucidation techniques are inconvenient or impractical. Though successful and widely adopted, folding algorithms make simplifying assumptions for loop regions due to their complex interactions and associated difficulty with generating energy parameters for relevant non-canonical pairing interactions. Modeling assumptions and a lack of energy parameters for loops limit accuracy in these functional critical regions of RNA. This work describes …


Mechanism Of Thermal Protein Aggregation: Experiments And Molecular Dynamics Simulations On The High-Temperature Behavior Of Myoglobin., Yuen Ki Ng, Nastaran N Tajoddin, Pablo M Scrosati, Lars Konermann Dec 2021

Mechanism Of Thermal Protein Aggregation: Experiments And Molecular Dynamics Simulations On The High-Temperature Behavior Of Myoglobin., Yuen Ki Ng, Nastaran N Tajoddin, Pablo M Scrosati, Lars Konermann

Chemistry Publications

Proteins that encounter unfavorable solvent conditions are prone to aggregation, a phenomenon that remains poorly understood. This work focuses on myoglobin (Mb) as a model protein. Upon heating, Mb produces amorphous aggregates. Thermal unfolding experiments at low concentration (where aggregation is negligible), along with centrifugation assays, imply that Mb aggregation proceeds via globally unfolded conformers. This contrasts studies on other proteins that emphasized the role of partially folded structures as aggregate precursors. Molecular dynamics (MD) simulations were performed to gain insights into the mechanism by which heat-unfolded Mb molecules associate with one another. A prerequisite for these simulations was the …


A Modular Strategy For Expanding Electron-Sink Capacity In Noncanonical Cluster Assemblies, Yume Mai, Alexandria K. Balzen, Rebecca K. Torren, Michael P. Callahan, Adam C. Colson Dec 2021

A Modular Strategy For Expanding Electron-Sink Capacity In Noncanonical Cluster Assemblies, Yume Mai, Alexandria K. Balzen, Rebecca K. Torren, Michael P. Callahan, Adam C. Colson

Chemistry and Biochemistry Faculty Publications and Presentations

A modular synthetic strategy is described whereby organometallic complexes exhibiting considerable electron-sink capacity may be assembled by using only a few simple molecular components. The Fe2(PPh2)2(CO)5 fragment was selected as a common electroactive component and was assembled around aromatic cores bearing one, two, or three isocyanide functional groups, with the resultant complexes possessing electron-sink capacities of two, four, and six electrons, respectively. The latter complex is noteworthy in that its electron-sink capacity was found to rival that of large multinuclear clusters (e.g., [Ni32C6(CO)36]6– and [Ni38 …


Metal Release From A Biomedical Cocrmo Alloy In Mixed Protein Solutions Under Static And Sliding Conditions: Effects Of Protein Aggregation And Metal Precipitation, Zheng Wei, Valentine Romanovski, Luimar Filho, Cecilia Persson, Yolanda S. Hedberg Dec 2021

Metal Release From A Biomedical Cocrmo Alloy In Mixed Protein Solutions Under Static And Sliding Conditions: Effects Of Protein Aggregation And Metal Precipitation, Zheng Wei, Valentine Romanovski, Luimar Filho, Cecilia Persson, Yolanda S. Hedberg

Chemistry Publications

Biomedical materials made of cobalt-chromium-molybdenum (CoCrMo) alloys are commonly used in artificial prostheses and dental implants, which are exposed to friction and load. The release of Co, Cr, and Mo from these surfaces is governed by physical and chemical processes. The extent of measured metal release from biomedical CoCrMo alloys into mixed protein solutions may be influenced by protein aggregation and metal precipitation effects. Metal release from, and the surface composition of, a CoCrMo alloy was investigated in physiological relevant solutions (phosphate buffered saline, PBS, with varying concentrations of fibrinogen from bovine plasma and/or bovine serum albumin) at pH 7.3 …


Single-Variable Porous Nanomaterial Series From Polymer Structure-Directing Agents, Morgan Stefik Dec 2021

Single-Variable Porous Nanomaterial Series From Polymer Structure-Directing Agents, Morgan Stefik

Faculty Publications

Block polymer structure-directing agents (SDA) enable the production of porous nanoscale materials. Most strategies rely upon polymer equilibration where diverse morphologies are realized in porous functional materials. This review details how solvent selectivity determines the polymer SDA behaviors, spanning from bulk-type to solution-type. Equilibrating behavior of either type, however, obscures nanostructure cause-and-effect since the resulting sample series convolve multiple spatial variations. Solution-type SDA behaviors include both dynamic and persistent micelles. Persistent micelle templates (PMT) use high solvent selectivity for kinetic entrapment. PMTs enable independent wall thickness control with demonstrated 2 Å precision alterations. Unimodal PMT pore size distributions have spanned …


Synergistic Broad-Spectrum Antibacterial Activity Of Hypoxis Hemerocallidea-Derived Silver Nanoparticles And Streptomycin Against Respiratory Pathobionts, Oluwole S. Aremu, T. Qwebani-Ogunleye, Lebogang Katata-Seru, Zimbili Mkhize, John F. Trant Dec 2021

Synergistic Broad-Spectrum Antibacterial Activity Of Hypoxis Hemerocallidea-Derived Silver Nanoparticles And Streptomycin Against Respiratory Pathobionts, Oluwole S. Aremu, T. Qwebani-Ogunleye, Lebogang Katata-Seru, Zimbili Mkhize, John F. Trant

Chemistry and Biochemistry Publications

Respiratory tract infections arise due to the introduction of microbes into the airway, disrupting the normal, healthy, complex interdependent microbiome. The selective disruption of this community can be either beneficial or dangerous. Nanoparticles are a potential tool for modifying this population. Coated silver nanoparticles (AgNPs) were synthesized using ethanolic extracts of Hypoxis hemerocallidea (EEHH), a Southern African plant used extensively in traditional medicine and the source of many bioactive secondary metabolites. The room temperature reaction between silver nitrate and EEHH forms largely spherical AgNPs with an average diameter of 6–20 nm. These nanoparticles show similar levels of antibacterial activity as …


New Isolate From Salvinia Molesta With Antioxidant And Urease Inhibitory Activity, Nadra Naheed, Saima Maher, Farooq Saleem, Ajmal Khan, Abdul Wadood, Saima Rasheed, M. Iqbal Choudhary, Matheus Froeyen, Iskandar Abdullah, Muhammad Usman Mirza, John F. Trant, Sarfraz Ahmad Dec 2021

New Isolate From Salvinia Molesta With Antioxidant And Urease Inhibitory Activity, Nadra Naheed, Saima Maher, Farooq Saleem, Ajmal Khan, Abdul Wadood, Saima Rasheed, M. Iqbal Choudhary, Matheus Froeyen, Iskandar Abdullah, Muhammad Usman Mirza, John F. Trant, Sarfraz Ahmad

Chemistry and Biochemistry Publications

Urease plays a significant role in the pathogenesis of urolithiasis pyelonephritis, urinary catheter encrustation, hepatic coma, hepatic encephalopathy, and peptic acid duodenal ulcers. Salvinia molesta was explored to identify new bioactive compounds with particular emphasis on urease inhibitors. The aqueous methanol extract was fractionated using solvents of increasing polarity. A series of column chromatography and later HPLC were performed on butanol extract. The structures of the resulting pure compounds were resolved using NMR (1D and 2D), infrared, and mass spectroscopy. The novel isolate was evaluated for antioxidant activity (using DPPH, superoxide anion radical scavenging, oxidative burst, and Fe+2 chelation assays), …


Identification Of Disease-Linked Hyperactivating Mutations In Ube3a Through Large-Scale Functional Variant Analysis, Kellan P. Weston, Xiaoyi Gao, Jinghan Zhao, Kwang Soo Kim, Susan E. Maloney, Jill Gotoff, Sumit Parikh, Yen Chen Leu, Kuen Phon Wu, Marwan Shinawi, Joshua P. Steimel, Joseph S. Harrison, Jason J. Yi Dec 2021

Identification Of Disease-Linked Hyperactivating Mutations In Ube3a Through Large-Scale Functional Variant Analysis, Kellan P. Weston, Xiaoyi Gao, Jinghan Zhao, Kwang Soo Kim, Susan E. Maloney, Jill Gotoff, Sumit Parikh, Yen Chen Leu, Kuen Phon Wu, Marwan Shinawi, Joshua P. Steimel, Joseph S. Harrison, Jason J. Yi

College of the Pacific Faculty Articles

The mechanisms that underlie the extensive phenotypic diversity in genetic disorders are poorly understood. Here, we develop a large-scale assay to characterize the functional valence (gain or loss-of-function) of missense variants identified in UBE3A, the gene whose loss-of-function causes the neurodevelopmental disorder Angelman syndrome. We identify numerous gain-of-function variants including a hyperactivating Q588E mutation that strikingly increases UBE3A activity above wild-type UBE3A levels. Mice carrying the Q588E mutation exhibit aberrant early-life motor and communication deficits, and individuals possessing hyperactivating UBE3A variants exhibit affected phenotypes that are distinguishable from Angelman syndrome. Additional structure-function analysis reveals that Q588 forms a regulatory site …


Triple Oxygen Isotope Constraints On Atmospheric O2 And Biological Productivity During The Mid-Proterozoic, Peng Liu, Jingjin Liu, Aoshaung Ji, Christopher T. Reinhard, Noah J. Planavsky, Dmitri Babikov, Raymond G. Najjar, James F. Kasting Dec 2021

Triple Oxygen Isotope Constraints On Atmospheric O2 And Biological Productivity During The Mid-Proterozoic, Peng Liu, Jingjin Liu, Aoshaung Ji, Christopher T. Reinhard, Noah J. Planavsky, Dmitri Babikov, Raymond G. Najjar, James F. Kasting

Chemistry Faculty Research and Publications

Reconstructing the history of biological productivity and atmospheric oxygen partial pressure (pO2) is a fundamental goal of geobiology. Recently, the mass-independent fractionation of oxygen isotopes (O-MIF) has been used as a tool for estimating pO2 and productivity during the Proterozoic. O-MIF, reported as Δ′17O, is produced during the formation of ozone and destroyed by isotopic exchange with water by biological and chemical processes. Atmospheric O-MIF can be preserved in the geologic record when pyrite (FeS2) is oxidized during weathering, and the sulfur is redeposited as sulfate. Here, sedimentary sulfates from …


Activation Of Prp28 Atpase By Phosphorylated Npl3 At A Critical Step Of Spliceosome Remodeling, F.-L. Yeh, S.-L. Chang, G. R. Ahmed, H.-I. Liu, L. Tung, C.-S. Yeh, L. S. Lanier, Corina Maeder, C.-M. Lin, S.-C. Tsai, W.-Y. Hsiao, W.-H. Chang, T.-H. Chang Dec 2021

Activation Of Prp28 Atpase By Phosphorylated Npl3 At A Critical Step Of Spliceosome Remodeling, F.-L. Yeh, S.-L. Chang, G. R. Ahmed, H.-I. Liu, L. Tung, C.-S. Yeh, L. S. Lanier, Corina Maeder, C.-M. Lin, S.-C. Tsai, W.-Y. Hsiao, W.-H. Chang, T.-H. Chang

Chemistry Faculty Research

Splicing, a key step in the eukaryotic gene-expression pathway, converts precursor messenger RNA (pre-mRNA) into mRNA by excising introns and ligating exons. This task is accomplished by the spliceosome, a macromolecular machine that must undergo sequential conformational changes to establish its active site. Each of these major changes requires a dedicated DExD/H-box ATPase, but how these enzymes are activated remain obscure. Here we show that Prp28, a yeast DEAD-box ATPase, transiently interacts with the conserved 5' splice-site (5'SS) GU dinucleotide and makes splicing-dependent contacts with the U1 snRNP protein U1C, and U4/U6.U5 tri-snRNP proteins, Prp8, Brr2, and Snu114. We further …


Anharmonic Vibrational Frequencies Of Water Borane And Associated Molecules, Brent R. Westbrook, Ryan C. Fortenberry Dec 2021

Anharmonic Vibrational Frequencies Of Water Borane And Associated Molecules, Brent R. Westbrook, Ryan C. Fortenberry

Faculty and Student Publications

Water borane (BH3 OH2 ) and borinic acid (BH2 OH) have been proposed as intermediates along the pathway of hydrogen generation from simple reactants: water and borane. However, the vibrational spectra for neither water borane nor borinic acid has been investigaged experimen-tally due to the difficulty of isolating them in the gas phase, making accurate quantum chemical predictions for such properties the most viable means of their determination. This work presents theoretical predictions of the full rotational and fundamental vibrational spectra of these two poten-tially application-rich molecules using quartic force fields at the CCSD(T)-F12b/cc-pCVTZ-F12 level with additional corrections included for …


A Tribute To Professor Gaetano Granozzi And His Contributions To Surface Science On The Occasion Of His 70th Birthday, Kurt W. Kolasinski Dec 2021

A Tribute To Professor Gaetano Granozzi And His Contributions To Surface Science On The Occasion Of His 70th Birthday, Kurt W. Kolasinski

Chemistry Faculty Publications

On the occasion of his 70th birthday, we celebrate the career of our Editor-in-Chief, Professor Gaetano Granozzi. Prof. Granozzi’s work is marked by his dedication to the fundamental understanding of technologically relevant systems through the lens of surface science.


Is Bog Water Chemistry Affected By Increasing N And S Deposition From Oil Sands Development In Northern Alberta, Canada?, R. Kelman Wieder, Melanie A. Vile, Kimberli D. Scott, James C. Quinn, Cara M. Albright, Kelly J. Mcmillen, Caitlyn Herron, Hope Fillingim Dec 2021

Is Bog Water Chemistry Affected By Increasing N And S Deposition From Oil Sands Development In Northern Alberta, Canada?, R. Kelman Wieder, Melanie A. Vile, Kimberli D. Scott, James C. Quinn, Cara M. Albright, Kelly J. Mcmillen, Caitlyn Herron, Hope Fillingim

Public Health Sciences Faculty Publications

Nitrogen and sulfur emissions from oil sands operations in northern Alberta, Canada have resulted in increasing deposition of N and S to the region's ecosystems. To assess whether a changing N and S deposition regime affects bog porewater chemistry, we sampled bog porewater at sites at different distances from the oil sands industrial center from 2009 to 2012 (10-cm intervals to a depth of 1 m) and from 2009 to 2019 (top of the bog water table only). We hypothesized that: (1) as atmospheric N and S deposition increases with increasing proximity to the oil sands industrial center, surface porewater …


On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop Dec 2021

On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

The admission by the Volkswagen Group in the fall of 2015 that they had duped the United States new vehicle emissions certification testing resulted in perhaps the most expensive violation of U.S. environmental vehicle emission regulations in its history. As part of the subsequent recall of more than 500,000 vehicles in the U.S., owners could sell their vehicles back to the companies or have them repaired. We have used a number of large on-road emission measurement data sets that were routinely collected before and after the recall to evaluate the fuel specific NOx emissions benefit for the vehicles that …


2d Covalent Organic Frameworks With An Incorporated Manganese Complex For Light Driven Carbon Dioxide Reduction, Denan Wang, Daniel Streater, Yun Peng, Jier Huang Dec 2021

2d Covalent Organic Frameworks With An Incorporated Manganese Complex For Light Driven Carbon Dioxide Reduction, Denan Wang, Daniel Streater, Yun Peng, Jier Huang

Chemistry Faculty Research and Publications

Covalent organic frameworks (COFs) have emerged as a novel class of crystalline porous photocatalytic materials due to their unique properties such as large surface area, tunable porosity, and rigid structure. In this work, we report the direct incorporation of a manganese CO2 molecular catalyst (MC) into COFs (Mn−TTA-COF) and the evaluation of its capability as photocatalyst for visible light driven CO2 reduction to form CO. We found that the photocatalytic activity of Mn−TTA-COF is quite low, which mainly results from the elimination of the CO ligand in the Mn MC upon light illumination, rendering its short duration in …


Conserved And Divergent Features Of Neuronal Camkii Holoenzyme Structure, Function, And Highorder Assembly, Olivia R. Buonarati, Adam P. Miller, Steven J. Coultrap, K. Ulrich Bayer, Steve L. Reichow Dec 2021

Conserved And Divergent Features Of Neuronal Camkii Holoenzyme Structure, Function, And Highorder Assembly, Olivia R. Buonarati, Adam P. Miller, Steven J. Coultrap, K. Ulrich Bayer, Steve L. Reichow

Chemistry Faculty Publications and Presentations

Neuronal CaMKII holoenzymes (a and b isoforms) enable molecular signal computation underlying learning and memory but also mediate excitotoxic neuronal death. Here, we provide a comparative analysis of these signaling devices, using single-particle electron microscopy (EM) in combination with biochemical and live cell imaging studies. In the basal state, both isoforms assemble mainly as 12-mers (but also 14-mers and even 16-mers for the b isoform). CaMKIIa and b isoforms adopt an ensemble of extended activatable states (with average radius of 12.6 versus 16.8 nm, respectively), characterized by multiple transient intra- and interholoenzyme interactions associated with distinct functional properties. The …


Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba Dec 2021

Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba

Student Scholar Symposium Abstracts and Posters

Forensic analysis of suspected narcotics is often dangerous as the substances’ composition is unknown. Many techniques for drug identification require handling of the substance outside of its packaging, which can expose the analyst to potentially harmful chemicals. The TruNarc Handheld Narcotics Analyzer is a portable Raman spectroscopy device that is non-destructive of evidence and can be used to screen drugs through simple packaging to minimize the risk of exposure. The Orange County Crime Lab (OCCL) is testing the limits of this device to determine if it can be used to screen new evidence within the Seized Drugs Lab. The OCCL …