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Chemistry Faculty Publications

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Full-Text Articles in Chemistry

Dual-Functional-Tag-Facilitated Protein Labeling And Immobilization, Xinyi Zhang, Wei Lu, Kevin Kwan, Dibakar Bhattacharyya, Yinan Wei Feb 2017

Dual-Functional-Tag-Facilitated Protein Labeling And Immobilization, Xinyi Zhang, Wei Lu, Kevin Kwan, Dibakar Bhattacharyya, Yinan Wei

Chemistry Faculty Publications

An important strategy in the construction of biomimetic membranes and devices is to use natural proteins as the functional components for incorporation in a polymeric or nanocomposite matrix. Toward this goal, an important step is to immobilize proteins with high efficiency and precision without disrupting the protein function. Here, we developed a dual-functional tag containing histidine and the non-natural amino acid azidohomoalanine (AHA). AHA is metabolically incorporated into the protein, taking advantage of the Met-tRNA and Met-tRNA synthetase. Histidine in the tag can facilitate metal-affinity purification, whereas AHA can react with an alkyne-functionalized probe or surface via well-established click chemistry. …


Controlled Microfabrication Of High-Aspect-Ratio Structures In Silicon At The Highest Etching Rates: The Role Of H2o2 In The Anodic Dissolution Of Silicon In Acidic Electrolytes, Chiara Cozzi, Giovanni Polito, Kurt W. Kolasinski, Giuseppe Barillaro Feb 2017

Controlled Microfabrication Of High-Aspect-Ratio Structures In Silicon At The Highest Etching Rates: The Role Of H2o2 In The Anodic Dissolution Of Silicon In Acidic Electrolytes, Chiara Cozzi, Giovanni Polito, Kurt W. Kolasinski, Giuseppe Barillaro

Chemistry Faculty Publications

In this work the authors report on the controlled electrochemical etching of high-aspect-ratio (from 5 to 100) structures in silicon at the highest etching rates (from 3 to 10 µm min−1) at room temperature. This allows silicon microfabrication entering a previously unattainable region where etching of high-aspect-ratio structures (beyond 10) at high etching rate (over 3 µm min−1) was prohibited for both commercial and research technologies. Addition of an oxidant, namely H2O2, to a standard aqueous hydrofluoric (HF) acid electrolyte is used to dramatically change the stoichiometry of the silicon dissolution process under anodic biasing without loss of etching control …


Enzyme–Free Uric Acid Electrochemical Sensors Using Β–Cyclodextrin Modified Carboxylic Acid Functionalized Carbon Nanotubes, Mulugeta B. Wayu, Margaret A. Schwarzmann, Samuel D. Gillespie, Michael C. Leopold Feb 2017

Enzyme–Free Uric Acid Electrochemical Sensors Using Β–Cyclodextrin Modified Carboxylic Acid Functionalized Carbon Nanotubes, Mulugeta B. Wayu, Margaret A. Schwarzmann, Samuel D. Gillespie, Michael C. Leopold

Chemistry Faculty Publications

Carboxylic acid-functionalized multi-walled carbon nanotubes (COOH-MWCNT) were modified via ultrasonication with β-cyclodextrin (β-CD) to obtain a COOH-MWCNT:β-CD nanocomposite material for the purpose of developing an enzyme-free electrochemical sensor for uric acid—a clinically relevant molecule implemented in pregnancy-induced hypertension diagnosis. The nanocomposite material is deposited onto glassy carbon electrodes and subsequently capped with layers of Nafion and Hydrothane polyurethane. The surface morphology and electronic structure of the nanocomposite material were characterized using UV–Vis, TEM, and FTIR. The performance of the electrochemical sensor was measured through direct injection of UA during amperometry. With the high surface area of the COOH-MWCNT in concert …


Hmba Is A Putative Hsp70 Activator Stimulating Hexim1 Expression That Is Down-Regulated By Estrogen, Rati Lama, Chunfang Gan, Nethrie Idippily, Viharika Bobba, David Danielpour, Monica Montano, Bin Su Ph.D. Feb 2017

Hmba Is A Putative Hsp70 Activator Stimulating Hexim1 Expression That Is Down-Regulated By Estrogen, Rati Lama, Chunfang Gan, Nethrie Idippily, Viharika Bobba, David Danielpour, Monica Montano, Bin Su Ph.D.

Chemistry Faculty Publications

Hexamethylene bis-acetamide inducible protein 1 (HEXIM1) is identified as a novel inhibitor of estrogen stimulated breast cell growth, and it suppresses estrogen receptor-a transcriptional activity. HEXIM1 protein level has been found to be downregulated by estrogens. Recently, HEXIM1 has been found to inhibit androgen receptor transcriptional activity as well. Researchers have used Hexamethylene bisacetamide (HMBA) for decades to stimulate HEXIM1 expression, which also inhibit estrogen stimulated breast cancer cell gene activation and androgen stimulated prostate cancer gene activation. However, the direct molecular targets of HMBA that modulate the induction of HEXIM1 expression in mammalian cells have not been identified. Based …


Inelastic Neutron Scattering Cross Section Measurements For 134,136Xe Of Relevance To Neutrinoless Double-Β Decay Searches, Erin E. Peters, T. J. Ross, S. H. Liu, Marcus T. Mcellistrem, Steven W. Yates Jan 2017

Inelastic Neutron Scattering Cross Section Measurements For 134,136Xe Of Relevance To Neutrinoless Double-Β Decay Searches, Erin E. Peters, T. J. Ross, S. H. Liu, Marcus T. Mcellistrem, Steven W. Yates

Chemistry Faculty Publications

Neutrinoless double-β decay (0νββ) searches typically involve large-scale experiments for which backgrounds can be complex. One possible source of background near the 0νββ signature in the observed spectra is γ rays arising from inelastic neutron scattering from the materials composing or surrounding the detector. In relation to searches for the 0νββ of 136Xe to 136Ba, such as the EXO-200 and KamLAND-Zen projects, inelastic neutron scattering γ-ray production cross sections for 136Xe and 134Xe are of importance for characterizing such γ rays that may inhibit the unambiguous identification of this yet-to-be-observed …


A Dilute-And-Shoot Flow-Injection Tandem Mass Spectrometry Method For Quantification Of Phenobarbital In Urine, Ravali Alagandula, Xiang Zhou, Baochuan Guo Jan 2017

A Dilute-And-Shoot Flow-Injection Tandem Mass Spectrometry Method For Quantification Of Phenobarbital In Urine, Ravali Alagandula, Xiang Zhou, Baochuan Guo

Chemistry Faculty Publications

RATIONALE: Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the gold standard of urine drug testing. However, current LC-based methods are time consuming, limiting the throughput of MS-based testing and increasing the cost. This is particularly problematic for quantification of drugs such as phenobarbital, which is often analyzed in a separate run because they must be negatively ionized.

METHODS: This study examined the feasibility of using a dilute-and-shoot flow-injection method without LC separation to quantify drugs with phenobarbital as a model system. Briefly, a urine sample containing phenobarbital was first diluted by 10 times, followed by flow injection of the diluted sample …


Regenerative Electroless Etching Of Silicon, Kurt W. Kolasinski, Nathan J. Gimbar, Haibo Yu, Mark Aindow, Ermei Mäkilä, Jarno Salonen Jan 2017

Regenerative Electroless Etching Of Silicon, Kurt W. Kolasinski, Nathan J. Gimbar, Haibo Yu, Mark Aindow, Ermei Mäkilä, Jarno Salonen

Chemistry Faculty Publications

Regenerative electroless etching (ReEtching), described herein for the first time, is a method of producing nanostructured semiconductors in which an oxidant (Ox1) is used as a catalytic agent to facilitate the reaction between a semiconductor and a second oxidant (Ox2) that would be unreactive in the primary reaction. Ox2 is used to regenerate Ox1, which is capable of initiating etching by injecting holes into the semiconductor valence band. Therefore, the extent of reaction is controlled by the amount of Ox2 added, and the rate of reaction is controlled by the injection rate of Ox2. This general strategy is demonstrated specifically …


A Redox-Neutral Catechol Synthesis, Q. Wu, D. Yan, Y. Chen, T. Wang, F. Xiong, W. Wei, Y. Lu, W. Sun, Jie Jack Li, J. Zhao Jan 2017

A Redox-Neutral Catechol Synthesis, Q. Wu, D. Yan, Y. Chen, T. Wang, F. Xiong, W. Wei, Y. Lu, W. Sun, Jie Jack Li, J. Zhao

Chemistry Faculty Publications

Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we report an iridium-catalysed tyrosinase-like approach to catechols, employing an oxyacetamide-directed C–H hydroxylation on phenols. This method achieves one-step, redox-neutral synthesis of catechols with diverse substituent groups under mild conditions. Mechanistic studies confirm that the directing group (DG) oxyacetamide acts as the oxygen source. This strategy has been applied to the synthesis of different important catechols with fluorescent property and bioactivity from the corresponding phenols. Finally, our method also provides a convenient route to 18O-labelled catechols using …


A Bioinspired And Biocompatible Ortho-Sulfiliminyl Phenol Synthesis, Feng Xiong, Liang Lu, Tian-Yu Sun, Qian Wu, Dingyuan Yan, Ying Chen, Xinhao Zhang, Wei Wei, Yi Lu, Wei-Yin Sun, Jie Jack Li, Jing Zhao Jan 2017

A Bioinspired And Biocompatible Ortho-Sulfiliminyl Phenol Synthesis, Feng Xiong, Liang Lu, Tian-Yu Sun, Qian Wu, Dingyuan Yan, Ying Chen, Xinhao Zhang, Wei Wei, Yi Lu, Wei-Yin Sun, Jie Jack Li, Jing Zhao

Chemistry Faculty Publications

Synthetic methods inspired by Nature often offer unique advantages including mild conditions and biocompatibility with aqueous media. Inspired by an ergothioneine biosynthesis protein EgtB, a mononuclear non-haem iron enzyme capable of catalysing the C–S bond formation and sulfoxidation, herein, we discovered a mild and metal-free C–H sulfenylation/intramolecular rearrangement cascade reaction employing an internally oxidizing O–N bond as a directing group. Our strategy accommodates a variety of oxyamines with good site selectivity and intrinsic oxidative properties. Combining an O–N bond with an X–S bond generates a C–S bond and an S¼N bond rapidly. The newly discovered cascade reaction showed excellent chemoselectivity …


Relative Properties And Relative Potency Of Various Hydrazide Compounds That Inhibit Growth Of Mycobacterium Tuberculosis, Ronald Bartzatt Jan 2017

Relative Properties And Relative Potency Of Various Hydrazide Compounds That Inhibit Growth Of Mycobacterium Tuberculosis, Ronald Bartzatt

Chemistry Faculty Publications

The molecular properties of compounds expressing growth inhibition of Mycobacterium tuberculosis are determined and examined for underlying relationships by pattern recognition methods. Pattern recognition methods such as hierarchical cluster analysis will show relationships between compounds. Descriptive statistical analysis of molecular properties reveal commonality among bacteriostatic compounds. Outliers within any category of descriptor is identified by Grubb’s test. Potency of growth inhibition measured as MIC (minimum inhibitory concentration) after in vitro evaluation will be compared and analyzed. Structure moieties and their effect on activity is identified. All compounds analyzed showed substantial growth inhibition of Mycobacterium tuberculosis, having MIC values ranging from …


Myeloperoxidase-Mediated Protein Lysine Oxidation Generates 2- Aminoadipic Acid And Lysine Nitrile In Vivo, Hongqiao Lin, Bruce S. Levison, Jennifer A. Buffa, Ying Huang, Xiaoming Fu, Zeneng Wang, Valentin Gogonea, Joseph A. Didonato, Stanley L. Hazen Jan 2017

Myeloperoxidase-Mediated Protein Lysine Oxidation Generates 2- Aminoadipic Acid And Lysine Nitrile In Vivo, Hongqiao Lin, Bruce S. Levison, Jennifer A. Buffa, Ying Huang, Xiaoming Fu, Zeneng Wang, Valentin Gogonea, Joseph A. Didonato, Stanley L. Hazen

Chemistry Faculty Publications

Recent studies reveal 2-aminoadipic acid (2-AAA) is both elevated in subjects at risk for diabetes and mechanistically linked to glucose homeostasis. Prior studies also suggest enrichment of protein-bound 2-AAA as an oxidative post-translational modification of lysyl residues in tissues associated with degenerative diseases of aging. While in vitro studies suggest redox active transition metals or myeloperoxidase (MPO) generated hypochlorous acid (HOCl) may produce protein-bound 2-AAA, the mechanism(s) responsible for generation of 2- AAA during inflammatory diseases are unknown. In initial studies we observed that traditional acid- or basecatalyzed protein hydrolysis methods previously employed to measure tissue 2-AAA can artificially generate …


Synthesis Of Vorinostat And Cholesterol Conjugate To Enhance The Cancer Cell Uptake Selectivity, Nethrie D. Idippily, Chunfang Gan, Paul Orefice, Jane Peterson, Bin Su Ph.D. Jan 2017

Synthesis Of Vorinostat And Cholesterol Conjugate To Enhance The Cancer Cell Uptake Selectivity, Nethrie D. Idippily, Chunfang Gan, Paul Orefice, Jane Peterson, Bin Su Ph.D.

Chemistry Faculty Publications

Histone deacetylase (HDAC) inhibitors modulate various cellular functions including proliferation, differentiation, and apoptosis. Vorinostat (SuberAniloHydroxamic Acid, SAHA) is the first HDAC inhibitor approved by FDA for cancer treatment. However, SAHA distributes in cancer tissue and normal tissue in similar levels. It will be ideal to selectively deliver SAHA into cancer cells. Rapidly growing cancer cells have a great need of cholesterol. Low-density lipoprotein (LDL) is the major cholesterol carrier in plasma and its uptake is mediated by LDL-receptor (LDL-R), a glycoprotein overexpressed on the surface of cancer cells. Herein, we designed and synthesized a SAHA cholesterol conjugate, and further formed …


Assessing In-Service Teachers’ Chemistry Content Knowledge And Self-Efficacy In Teaching The K To 12 Science Curriculum, Yna Camille A. Mongcal, Queena N. Lee-Chua, Armando M. Guidote Jr Jan 2017

Assessing In-Service Teachers’ Chemistry Content Knowledge And Self-Efficacy In Teaching The K To 12 Science Curriculum, Yna Camille A. Mongcal, Queena N. Lee-Chua, Armando M. Guidote Jr

Chemistry Faculty Publications

As the K to 12 Science program was formally implemented, interventions to enhance competence and confidence of teachers in teaching science in a spiral progression approach are main concerns. This study aims to assess the chemistry content knowledge and self-efficacy of 38 in-service teachers enrolled in a graduate program from a teacher education institution using a content knowledge test (CKT) and a self-efficacy beliefs scale (SeS) using a mixed-method approach. Quantitative findings reveal that the least mastered topics in chemistry of the teacher-respondents include solutions, chemical bonding, the mole concept, gas laws, and chemical reactions. The science teachers say they …


Weikangning Therapy In Functional Dyspepsia And The Protective Role Of Nrf2, Yujuan Chang, Wei Wei, Li Tong, Yanjun Liu, Aimin Zhou, Jiande Chen, Ruhan Wei, Ping Zhang, Xiaolan Su Jan 2017

Weikangning Therapy In Functional Dyspepsia And The Protective Role Of Nrf2, Yujuan Chang, Wei Wei, Li Tong, Yanjun Liu, Aimin Zhou, Jiande Chen, Ruhan Wei, Ping Zhang, Xiaolan Su

Chemistry Faculty Publications

Functional dyspepsia (FD) is a non-organic gastro-intestinal disorder that has a marked negative impact on quality of life. Compared with conventional pharmacological therapies, the traditional Chinese medicine weikangning (WKN) is a safe and effective treatment for FD. The present study aimed to determine the molecular mechanisms underlying the efficacy of WKN. The effect of different concentrations of WKN on the proliferation of the human gastric mucosal epithelial cell line GES-1 was assessed. The optimal WKN concentration to promote cell proliferation was determined, and this concentration was used to examine the effect of WKN compared with a domperidone-treated positive control group …


Charge Transfer At The Liquid/Solid Interface To Affect Nanostructure Formation, Kurt W. Kolasinski Jan 2017

Charge Transfer At The Liquid/Solid Interface To Affect Nanostructure Formation, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.


Synthetic Melanin Films As Potential Interfaces For Peroxynitrite Detection And Quantification, Haitham F. Kalil, Shaimaa Mahera, Tiyash Bosed, Ousama Al-Mahmoude, Clara Kay, Mekki Bayachou Jan 2017

Synthetic Melanin Films As Potential Interfaces For Peroxynitrite Detection And Quantification, Haitham F. Kalil, Shaimaa Mahera, Tiyash Bosed, Ousama Al-Mahmoude, Clara Kay, Mekki Bayachou

Chemistry Faculty Publications

Peroxynitrite (PON) is a highly reactive oxygen-nitrogen species that facilitates both oxidation and nitration reactions. Early reports have revealed the deleterious effects of PON on DNA, proteins, and lipids. Recent studies have suggested that melanin can act as an antioxidative therapy to scavenge the reactive oxygen-nitrogen species (RO-NS) including PON. Melanin is a natural pigment that has many physiological functions involving the neutralization of highly oxidative species. In this project, the interaction between PON and synthetic melanin has been studied. In addition, the electrochemical characteristics of the polymerized 5,6-dihydroxy indole (DHI) as a model of synthetic melanin were examined using …


Chemical Profiling And Chemical Standardization Of Vitex Negundo Using 13c Nmr, Fabian M. Dayrit, Lolita G. Lagurin, John Daniel J. Magsalin, Anthony R. Zosa Jan 2017

Chemical Profiling And Chemical Standardization Of Vitex Negundo Using 13c Nmr, Fabian M. Dayrit, Lolita G. Lagurin, John Daniel J. Magsalin, Anthony R. Zosa

Chemistry Faculty Publications

Chemical profiling and standardization of the defatted methanol extract of the leaves of Vitex negundo L. were carried out using 13C nuclear magnetic resonance (NMR) analysis followed by chemometric analysis of the chemical shift data. Chemical profile was obtained using a k-means cluster profile and chemical standardization which was achieved using a multivariate control chart. The V. negundo samples were made up of four groups: the training set, submitted samples from production farms, commercial samples, such as tablets, capsules and teas, and experimental samples (samples which were allowed to degrade). Four groups were generated in k-means cluster, which generally corresponded …


Comparative Proteomic Analyses Of The Parietal Lobe From Rhesus Monkeys Fed A High-Fat/Sugar Diet With And Without Resveratrol Supplementation, Relative To A Healthy Diet: Insights Into The Roles Of Unhealthy Diets And Resveratrol On Function, Aaron M. Swomley, Judy C. Triplett, Jeriel T. Keeney, Govind Warrier, Kevin J. Pearson, Julie A. Mattison, Rafael De Cabo, Jian Cai, Jon B. Klein, D. Allan Butterfield Jan 2017

Comparative Proteomic Analyses Of The Parietal Lobe From Rhesus Monkeys Fed A High-Fat/Sugar Diet With And Without Resveratrol Supplementation, Relative To A Healthy Diet: Insights Into The Roles Of Unhealthy Diets And Resveratrol On Function, Aaron M. Swomley, Judy C. Triplett, Jeriel T. Keeney, Govind Warrier, Kevin J. Pearson, Julie A. Mattison, Rafael De Cabo, Jian Cai, Jon B. Klein, D. Allan Butterfield

Chemistry Faculty Publications

A diet consisting of a high intake of saturated fat and refined sugars is characteristic of a Western-diet and has been shown to have a substantial negative effect on human health. Expression proteomics were used to investigate changes to the parietal lobe proteome of rhesus monkeys consuming either a high fat and sugar (HFS) diet, a HFS diet supplemented with resveratrol (HFS+RSV), or a healthy control diet for 2 years. Here we discuss the modifications in the levels of 12 specific proteins involved in various cellular systems including metabolism, neurotransmission, structural integrity, and general cellular signaling following a nutritional intervention. …


Potency And Properties Of Hydrazide Compounds That Inhibit The Growth Of Mycobacterium Tuberculosis, Ronald Bartzatt Dec 2016

Potency And Properties Of Hydrazide Compounds That Inhibit The Growth Of Mycobacterium Tuberculosis, Ronald Bartzatt

Chemistry Faculty Publications

Aims: To examine the properties of hydrazide compounds shown to inhibit Mycobacterium tuberculosis. To identify properties that affect efficiency of bacterial inhibition.

Study Design: Utilizing data from previous studies of compounds that inhibit Mycobacterium tuberculosis, then statistical and pattern recognition methods are applied to identify interrelationships.

Place and Duration of Study: Department of Chemistry, Durham Science Center, University of Nebraska at Omaha, from January 2016 to July 2016.

Methodology: Interrelationships of pharmacological properties were identified by use of various pattern recognition techniques, such as hierarchical cluster analysis and path analysis. Molecular properties and descriptors for all compounds were …


Myofilament Calcium Sensitivity: Consequences Of The Effective Concentration Of Troponin I, Jalal K. Siddiqui, Svetlana B. Tikunova, Shane D. Walton, Bin Liu, Meredith Meyer, Pieter P. De Tombe, Nathan Neilson, Peter M. Kekenes-Huskey, Hussam E. Salhi, Paul M.L. Janssen, Brandon J. Biesiadecki, Jonathan P. Davis Dec 2016

Myofilament Calcium Sensitivity: Consequences Of The Effective Concentration Of Troponin I, Jalal K. Siddiqui, Svetlana B. Tikunova, Shane D. Walton, Bin Liu, Meredith Meyer, Pieter P. De Tombe, Nathan Neilson, Peter M. Kekenes-Huskey, Hussam E. Salhi, Paul M.L. Janssen, Brandon J. Biesiadecki, Jonathan P. Davis

Chemistry Faculty Publications

Control of calcium binding to and dissociation from cardiac troponin C (TnC) is essential to healthy cardiac muscle contraction/relaxation. There are numerous aberrant post-translational modifications and mutations within a plethora of contractile, and even non-contractile, proteins that appear to imbalance this delicate relationship. The direction and extent of the resulting change in calcium sensitivity is thought to drive the heart toward one type of disease or another. There are a number of molecular mechanisms that may be responsible for the altered calcium binding properties of TnC, potentially the most significant being the ability of the regulatory domain of TnC to …


Electropolymerization Of B–Cyclodextrin Onto Multi–Walled Carbon Nanotube Composite Films For Enhanced Selective Detection Of Uric Acid, Mulugeta B. Wayu, Luke T. Dipasquale, Margaret A. Schwarzmann, Samuel D. Gillespie, Michael C. Leopold Dec 2016

Electropolymerization Of B–Cyclodextrin Onto Multi–Walled Carbon Nanotube Composite Films For Enhanced Selective Detection Of Uric Acid, Mulugeta B. Wayu, Luke T. Dipasquale, Margaret A. Schwarzmann, Samuel D. Gillespie, Michael C. Leopold

Chemistry Faculty Publications

An amperometric uric acid (UA) sensor incorporating a multi-walled carbon nanotubes (MWCNT) network in Nafion and electropolymerized β-cyclodextrin (β-CD) layer is investigated. The electrochemical sensor is comprised of a glassy carbon electrode modified with Nafion-MWCNT nanocomposite film, a β-CD polymer inner selective layer, and a Hydrothane polyurethane (HPU) outer selective coating. The surface morphology and electronic structure of the electrode material are characterized using transmission electron microscopy (TEM), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) spectroscopy. The electrocatalytic activity of the sensor is studied using cyclic voltammetry (CV), chronocoulometry (CC) and differential pulse voltammetry (DPV). Analytical performance of …


Secondary Structure Adopted By The Gly-Gly-X Repetitive Regions Of Dragline Spider Silk, Geoffrey M Gray, Arjan Van Der Vaart, Chengchen Guo, Justin Jones, David Onofrei, Brian R Cherry, Randolph V Lewis, Jeffery L Yarger, Gregory P Holland Dec 2016

Secondary Structure Adopted By The Gly-Gly-X Repetitive Regions Of Dragline Spider Silk, Geoffrey M Gray, Arjan Van Der Vaart, Chengchen Guo, Justin Jones, David Onofrei, Brian R Cherry, Randolph V Lewis, Jeffery L Yarger, Gregory P Holland

Chemistry Faculty Publications

Solid-state NMR and molecular dynamics (MD) simulations are presented to help elucidate the molecular secondary structure of poly(Gly-Gly-X), which is one of the most common structural repetitive motifs found in orb-weaving dragline spider silk proteins. The combination of NMR and computational experiments provides insight into the molecular secondary structure of poly(Gly-Gly-X) segments and provides further support that these regions are disordered and primarily non-β-sheet. Furthermore, the combination of NMR and MD simulations illustrate the possibility for several secondary structural elements in the poly(Gly-Gly-X) regions of dragline silks, including β-turns, 3


Subtractive Methods To Form Pyrite And Sulfide Nanostructures Of Fe, Co, Ni, Cu And Zn, Kurt W. Kolasinski Dec 2016

Subtractive Methods To Form Pyrite And Sulfide Nanostructures Of Fe, Co, Ni, Cu And Zn, Kurt W. Kolasinski

Chemistry Faculty Publications

The low Z metals Fe, Co, Ni, Cu and Zn are Earth abundant, i.e. inexpensive, and their sulfides are of low toxicity. This makes them appealing candidates for materials applications requiring semiconductors or, in the case of CoS2, a metal since they can potentially be produced in large quantities and low cost. Though of great potential little work has explored how subtractive methods can be used to form nanostructured and/or porous structures in, e.g. FeS2, CoS2, NiS, Cu2S and ZnS.


Glutathione Species And Metabolomic Prints In Subjects With Liver Disease As Biological Markers For The Detection Of Hepatocellular Carcinoma, Juan R. Sanabria, Rajan S. Kombu, Guo Fang Zhang, Yana Sandlers, Jizhou Ai, Rafael A. Ibarra, Rime Abbas, Kush Goyal, Henri Brunengraber Dec 2016

Glutathione Species And Metabolomic Prints In Subjects With Liver Disease As Biological Markers For The Detection Of Hepatocellular Carcinoma, Juan R. Sanabria, Rajan S. Kombu, Guo Fang Zhang, Yana Sandlers, Jizhou Ai, Rafael A. Ibarra, Rime Abbas, Kush Goyal, Henri Brunengraber

Chemistry Faculty Publications

© 2016 The Authors Background The incidence of liver disease is increasing in USA. Animal models had shown glutathione species in plasma reflects liver glutathione state and it could be a surrogate for the detection of hepatocellular carcinoma (HCC). Methods The present study aimed to translate methods to the human and to explore the role of glutathione/metabolic prints in the progression of liver dysfunction and in the detection of HCC. Treated plasma from healthy subjects (n = 20), patients with liver disease (ESLD, n = 99) and patients after transplantation (LTx, n = 7) were analyzed by GC- or LC/MS. …


Spray Printing Of Organic Semiconducting Single Crystals, Grigorios-Panagiotis Rigas, Marcia M. Payne, John E. Anthony, Peter N. Horton, Fernando A. Castro, Maxim Shkunov Nov 2016

Spray Printing Of Organic Semiconducting Single Crystals, Grigorios-Panagiotis Rigas, Marcia M. Payne, John E. Anthony, Peter N. Horton, Fernando A. Castro, Maxim Shkunov

Chemistry Faculty Publications

Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by …


Giant Electrorheological Fluids With Ultrahigh Electrorheological Efficiency Based On A Micro/Nano Hybrid Calcium Titanyl Oxalate Composite, Jinghua Wu, Zhenyang Song, Fenghua Liu, Jianjun Guo, Yuchuan Cheng, Shengqian Ma, Gaojie Xu Nov 2016

Giant Electrorheological Fluids With Ultrahigh Electrorheological Efficiency Based On A Micro/Nano Hybrid Calcium Titanyl Oxalate Composite, Jinghua Wu, Zhenyang Song, Fenghua Liu, Jianjun Guo, Yuchuan Cheng, Shengqian Ma, Gaojie Xu

Chemistry Faculty Publications

A novel micro/nanoparticle hybrid calcium titanyl oxalate electrorheological (ER) material composed of micron-sized spindly particles and nanometer-sized irregular particles was successfully fabricated. The giant ER fluid based on the composite exhibits enhanced not only yield stress but also low field-off viscosity, thereby resulting in an ultrahigh ER efficiency that greatly exceeds that of any existing giant ER (GER) material. The synergistic effect between the spindly microparticles and irregular nanoparticles discovered in this study suggests a promising method for solving the long-standing ER efficiency problems. Moreover, the one-step synthesis approach presented in this work can be readily expanded for mass production …


Towards An Understanding Of The Propensity For Crystalline Hydrate Formation By Molecular Compounds, Alankriti Bajpai, Hayley S Scott, Tony Pham, Kai-Jie Chen, Brian Space, Matteo Lusi, Miranda L Perry, Michael J Zaworotko Nov 2016

Towards An Understanding Of The Propensity For Crystalline Hydrate Formation By Molecular Compounds, Alankriti Bajpai, Hayley S Scott, Tony Pham, Kai-Jie Chen, Brian Space, Matteo Lusi, Miranda L Perry, Michael J Zaworotko

Chemistry Faculty Publications

Hydrates are technologically important and ubiquitous yet they remain a poorly understood and understudied class of molecular crystals. In this work, we attempt to rationalize propensity towards hydrate formation through crystallization studies of molecules that lack strong hydrogen-bond donor groups. A Cambridge Structural Database (CSD) survey indicates that the statistical occurrence of hydrates in 124 molecules that contain five- and six-membered N-heterocyclic aromatic moieties is 18.5%. However, hydrate screening experiments on a library of 11 N-heterocyclic aromatic compounds with at least two acceptor moieties and no competing hydrogen-bond donors or acceptors reveals that over 70% of this group …


Imparting Amphiphobicity On Single-Crystalline Porous Materials., Qi Sun, Hongming He, Wen-Yang Gao, Briana Aguila, Lukasz Wojtas, Zhifeng Dai, Jixue Li, Yu-Sheng Chen, Feng-Shou Xiao, Shengqian Ma Oct 2016

Imparting Amphiphobicity On Single-Crystalline Porous Materials., Qi Sun, Hongming He, Wen-Yang Gao, Briana Aguila, Lukasz Wojtas, Zhifeng Dai, Jixue Li, Yu-Sheng Chen, Feng-Shou Xiao, Shengqian Ma

Chemistry Faculty Publications

The sophisticated control of surface wettability for target-specific applications has attracted widespread interest for use in a plethora of applications. Despite the recent advances in modification of non-porous materials, surface wettability control of porous materials, particularly single crystalline, remains undeveloped. Here we contribute a general method to impart amphiphobicity on single-crystalline porous materials as demonstrated by chemically coating the exterior of metal-organic framework (MOF) crystals with an amphiphobic surface. As amphiphobic porous materials, the resultant MOF crystals exhibit both superhydrophobicity and oleophobicity in addition to retaining high crystallinity and intact porosity. The chemical shielding effect resulting from the amphiphobicity of …


The Tribology And Chemistry Of Phosphorus Containing Lubricant Additives, David W. Johnson Oct 2016

The Tribology And Chemistry Of Phosphorus Containing Lubricant Additives, David W. Johnson

Chemistry Faculty Publications

Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. Recently, phosphorus‐containing ionic liquids have emerged as a new class of lubricant additives. While the use of phosphorus compounds has been extensive, a detailed knowledge of how they work has been a much more recent development. In this chapter, the use of phosphate esters, thiophosphate esters, metal thiophosphates and phosphorus‐containing ionic liquids as antiwear or extreme pressure additives is discussed. The primary emphasis will be on how they form a protective film, which is both durable and reduces friction. The first part of …


Water Quality In And Around Glen Helen Nature Preserve Fall 2016, Krista Baumgartner, Kellie Bohrer, Brandon Bresler, Thomas Chenault, Miriam Crane, Jennifer Dean, James Herbort, Kelsey Hood, Megan Shade, Kraig Strayer, Nicholas Yahana, Emily Warren, Ben Silliman, Brandon Myers, Steven Ujvary, Audrey E. Mcgowin Oct 2016

Water Quality In And Around Glen Helen Nature Preserve Fall 2016, Krista Baumgartner, Kellie Bohrer, Brandon Bresler, Thomas Chenault, Miriam Crane, Jennifer Dean, James Herbort, Kelsey Hood, Megan Shade, Kraig Strayer, Nicholas Yahana, Emily Warren, Ben Silliman, Brandon Myers, Steven Ujvary, Audrey E. Mcgowin

Chemistry Faculty Publications

No abstract provided.