Chemistry Commons^™

The Zinc-Binding Domain Of Mammalian Prolyl-Trna Synthetase Is Indispensable For Catalytic Activity And Organism Viability, Kommireddy Vasu, Iyappan Ramachandiran, Fulvia Terenzi, Debjit Khan, Arnab China, Krishnendu Khan, Aayushi Chechi, Camelia Baleanu-Gogonea, Valentin Gogonea, Paul L. Fox

Chemistry Faculty Publications

Aminoacyl-tRNA synthetases (AARS) participate in decoding the genome by catalyzing conjugation of amino acids to their cognate tRNAs. During evolution, biochemical and environmental conditions markedly influenced the sequence and structure of the 20 AARSs, revealing adaptations dictating canonical and orthogonal activities. Here, we investigate the function of the appended Zn2+-binding domain (ZBD) in the bifunctional AARS, glutamyl-prolyl-tRNA synthetase (GluProRS). We developed GluProRS mutant mice by CRISPR-Cas9 with a deletion of 29 C-terminal amino acids, including two of four Zn2+-coordinating cysteines. Homozygous ZBD mutant mice die before embryonic day 12.5, but heterozygous mice are healthy. ZBD disruption profoundly reduces GluProRS canonical …

Alternative View Of Oxygen Reduction On Porous Carbon Electrocatalysts: The Substance Of Complex Oxygen-Surface Interactions, Giacomo De Falco, Marc Florent, Jacek Jagiello, Yongqiang Cheng, Luke L. Daemen, Anibal J. Ramirez-Cuesta, Teresa J. Bandosz

Publications and Research

Electrochemical oxygen reduction reaction (ORR) is an important energy-related process requiring alternative catalysts to expensive platinum-based ones. Although recently some advancements in carbon catalysts have been reported, there is still a lack of understanding which surface features might enhance their efficiency for ORR. Through a detailed study of oxygen adsorption on carbon molecular sieves and using inelastic neutron scattering, we demonstrated here that the extent of oxygen adsorption/interactions with surface is an important parameter affecting ORR. It was found that both the strength of O2 physical adsorption in small pores and its specific interactions with surface ether functionalities in the …

Improving Sers Detection Of Illicit Drugs Using A Plasmonic Substrate Modified With Self-Assembled Monolayers, John Harms

Theses and Dissertations

Due to the worsening national drug epidemic and increasing prevalence of exceptionally potent synthetic opioids, there is a need to improve the forensic detection of illicit drugs, including sample analyses conducted on-site. In this thesis, the analysis of several illicit drugs spotted onto plasmonic surfaces was investigated using surface-enhanced Raman spectroscopy (SERS) with the goal of improving detection limits. Plasmonic surfaces (gold nanoparticle-loaded filter papers) were prepared and characterized prior to their SERS applications. Plasmonic surfaces were then further modified for improved SERS detection of each illicit drug with the treatment of self-assembled monolayer (SAM) forming compounds; in addition to …

A Systematic Multiscale Investigation Of Nanoparticle-Assisted Co2 Enhanced Oil Recovery (Eor) Process For Shale Oil Reservoirs, Dayo A. Afekare

LSU Doctoral Dissertations

Shale oil reservoirs are prolific on the short term due to hydraulic fracturing and horizontal drilling but experience significant production decline, leading to poor ultimate recovery and leaving billions of barrels of oil buried in the ground. In this study, a systematic multi-scale investigation of an enhanced oil recovery (EOR) process using relatively inexpensive silicon dioxide nanoparticles and carbon dioxide for shale oil reservoirs was conducted. Using the Tuscaloosa Marine Shale (TMS) as a case study, aqueous dispersions of nanosilica in conjunction with CO₂ were investigated at nano-to-core scales. At the nanoscale, atomic force microscope was used to investigate …

Investigations Of The Structure And Protein-Protein Interactions Of Chlamydia Trachomatis Scc4, Thilini Oshadhi Senarath Ukwaththage

LSU Doctoral Dissertations

Chlamydia trachomatis (CT) is the most common, sexually transmitted bacterial disease (STD) in the world. In the developmental cycle of CT, specific chlamydia chaperone 4 (Scc4) is a unique protein with essential and multiple roles. Hence, Scc4 is significant as a virulence target for therapeutic approaches to treat chlamydial infections. A novel approach was discovered to purify tag free Scc4 by utilizing a 6X-histidine-tag on Scc1 in the co-expressed Scc4:Scc1 complex by capturing the complex on nickel-charged immobilized metal affinity chromatography resin, followed by dissociation of Scc4 with sarkosyl. Using triple resonance NMR experiments, backbone and sidechain resonances …

Novel Synthetic Transformations Targeting Δ-Valerolactone And Isocoumarin, Joshua Paul Van Houten

LSU Doctoral Dissertations

The purpose of this dissertation is to describe the efforts undertaken to develop synthetic methodology targeting δ-valerolactone and isocoumarin. At the onset, an introduction to the δ-valerolactone and isocoumarin is given. Relevant examples of δ-valerolactone being utilized in the production of materials of biological and industrial application are then discussed. Following, current methods for forming δ-valerolactone are presented. After, an introduction to isocoumarin is begun. Current methods for producing isocoumarin are then discussed.

The results and discussion section of this dissertation will focus on two methods that were explored with the goal of producing α-acyl-δ-valerolactone with two different substitution patterns. …

Designing Ionic Liquid-Derived Polymer Composites From Poly(Ionic Liquid)–Ionene Semi-Interpenetrating Networks, Kathryn E. O'Harra, George E. Timmerman, Jason E. Barra, Kevin Miller

Faculty & Staff Research and Creative Activity

While the solvating power of ionic liquids (ILs) for a variety of solute types including polymers is well-known, the use of ILs as solvents for ionenes—charged polymers with cationic moieties within the backbone—has only recently begun to be explored. IL–ionene combinations offer vast possibilities to make iongels and perhaps even use ILs to exert control over ionene organization (i.e., coil or rod). If the IL solvent is also polymerizable, then poly(IL)–ionene semi-interpenetrating networks (semi-IPNs) can be achieved. This study reports, for the first time, examples of poly(IL)–ionene semi-IPNs formed by dissolving an ionene in a vinyl-functionalized imidazolium IL followed by …

Influence Of Counteranion And Humidity On The Thermal, Mechanical And Conductive Properties Of Covalently Crosslinked Ionenes, Nicholas C. Bontrager, Samantha Radomski, Samantha P. Daymon, R. Daniel Johnson, Kevin M. Miller

Faculty & Staff Research and Creative Activity

Thiol-ene photopolymerization was used to generate a series of covalently crosslinked, imidazolium-containing ionene networks. A variety of counteranions were chosen so as to investigate the influence of size and basicity on the thermal, mechanical and conductive properties of the resulting networks. Anhydrous conductivities at 20 °C were found to be on the order of 10−6 to 10−10 S/cm and correlated to some degree with Tg; however, Tg-normalization of the curves indicated that this relationship between polymer structure and conductivity was more complex. VFT fitting, along with free ion concentration and ion mobility data, were investigated in order to …

Advances In Ultra-High-Pressure And Multi-Dimensional Liquid Chromatography Instrumentation And Workflows, Jelle De Vos, Dwight Stoll, Stephan Buckenmaier, Sebastiaan Eeltink, James P. Grinias

College of Science & Mathematics Departmental Research

The present contribution discusses recent advances in ultra-high-pressure liquid chromatography (UHPLC) and multi-dimensional liquid chromatography (MDLC) technology. First, new developments in UHPLC column technology and system design are highlighted. The latter includes a description of a novel injector concept enabling method speed-up, emerging detectors, and instrument diagnostics approaches. Next, online MDLC workflows are reviewed and advances in modulation technology are highlighted. Finally, key applications published in 2020 are reviewed.

Synthesis Of Oxyquinoliziniporphyrins And Pyridoquinoliziniporphyrins, Emma Cramer

Theses and Dissertations

N-confused porphyrins are porphyrin analogues that introduce a nitrogen outside of the macrocyclic cavity. Two novel N-confused type porphyrins were targeted for this study. Both syntheses use the key intermediate 4-quinolizone. Previous studies of N-confused pyriporphyrin showed that the system is nonaromatic and resembles structurally analogous benziporphyrins. However, modifications to systems of this type can introduce aromatic characteristics. The first system targeted introduced a quinolizone subunit into a porphyrin system. Quinolizone contains a thermodynamically stable amide and this unit disrupts the aromatic pathway. However, dipolar resonance contributors can potentially reinstate some aromatic character. A quinolizone dialdehyde was condensed with tripyrranes …

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Atomic-Resolution 1.3 Å Crystal Structure, Inhibition By Sulfate, And Molecular Dynamics Of The Bacterial Enzyme Dape, Matthew Kochert, Boguslaw P. Nocek, Thahani S. Habeeb Mohammad, Elliot Gild, Kaitlyn Lovato, Tahirah K. Heath, Richard C. Holz, Kenneth W. Olsen, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

We report the atomic-resolution (1.3 Å) X-ray crystal structure of an open conformation of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE, EC 3.5.1.18) from Neisseria meningitidis. This structure [Protein Data Bank (PDB) entry 5UEJ] contains two bound sulfate ions in the active site that mimic the binding of the terminal carboxylates of the N-succinyl-l,l-diaminopimelic acid (l,l-SDAP) substrate. We demonstrated inhibition of DapE by sulfate (IC50 = 13.8 ± 2.8 mM). Comparison with other DapE structures in the PDB demonstrates the flexibility of the interdomain connections of this protein. This high-resolution structure was then utilized as the …

Three-Way Analysis-Based Ph-Uv-Vis Spectroscopy For Quantifying Allura Red In An Energy Drink And Determining Colorant's Pka, Erdal Dinç Prof., Nazangül Ünal, Zehra Ceren Ertekin

Journal of Food and Drug Analysis

Three-way analysis-based pH-UV-Vis spectroscopy was proposed for quantifying allura red in an energy drink product without the need for chromatographic analysis, and determining the colorant’s pKa without using any titration technique. In this study, UV-Vis spectroscopic data matrices were obtained from absorbance measurements at five different pH levels from pH 8 to pH 12 and arranged as a three-way array (wavelength x sample x pH). In the three-way analysis procedure, parallel factor analysis (PARAFAC) was implemented to decompose the three-way array into a set of trilinear components. Each set of three components relates to spectral, pH and relative concentration profiles …

Representing Methane Emissions From Wet Tropical Forest Soils Using Microbial Functional Groups Constrained By Soil Diffusivity, Debjani Sihi, Xiaofeng Xu, Mónica Salazar Ortiz, Christine S. O'Connell, Whendee L. Silver, Carla López-Lloreda, Julia M. Brenner, Ryan K. Quinn, Jana R. Phillips, Brent D. Newman, Melanie A. Mayes

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Tropical ecosystems contribute significantly to global emissions of methane (CH₄), and landscape topography influences the rate of CH₄ emissions from wet tropical forest soils. However, extreme events such as drought can alter normal topographic patterns of emissions. Here we explain the dynamics of CH₄ emissions during normal and drought conditions across a catena in the Luquillo Experimental Forest, Puerto Rico. Valley soils served as the major source of CH₄ emissions in a normal precipitation year (2016), but drought recovery in 2015 resulted in dramatic pulses in CH₄ emissions from all topographic positions. Geochemical parameters …

Novel Phenolic Deep Eutectic Solvents For Desulfurisation Of Petrodiesel, Idrees Bakr Qader, Jalil H. Kareem, Hani K. Ismail, Hawbash K. Mahmood

Karbala International Journal of Modern Science

In this work, a novel production of “deep eutectic solvents (DESs)” has been utilised for the elimination of sulfur composition, particularly from crude oil by liquid-liquid extraction. Herein, we present the first demonstration of the use of novel DESs formed by phenol, catechol, resorcinol and o-cresol as “hydrogen bond donors (HBDs)” with trimethyl hydroxyammonium chloride (ChCl) as the hydrogen bond acceptor to affect the efficient separation of organosulfur compounds from diesel. These DES electrolytes have been applied for the sulfur extraction from Iraqi real diesel fuel as determined using X-ray florescence sulfur measurements. The optimisation condition factors in this research …

Anticancer And Antiangiogenic Activities Of Alkaloids Isolated From Lantana Camara By Adsorption On The Magnetic Nanoparticles, Hussein Kadhem Al-Hakeim, Rahman Sahib Al-Zabibah, Huda Falah Alzihari, Ali Khudhair Almensoori, Hazim A. Al-Zubaidi, Loiy Elsir Ahmed Hassan Hassan

Karbala International Journal of Modern Science

Lantana camara L. (L. camara) is a perennial shrub that contains low amounts of alkaloids. In the present study, the magnetic nanoparticles (MNPs) were used to isolate positively charged alkaloids from the methanolic extract of L. camara leaves. The crude alkaloid was fractionated using HPLC to separate the highest peak of the alkaloid fraction (HPAF). The crude alkaloids (CA) and HPAF were tested for their antiproliferative effect against cancer cell lines (MCF-7, HCT-116, and HeLa) and endothelial cells line (EA.hy926) as a standard cell line. Antiangiogenic properties were examined using rat aortic ring assay. …

Mach-Zehnder Quantum Interference Rules In Hydrocarbons With Substituents, Alaa Al-Jobory, Zainelabideen Y. Mijbil

Karbala International Journal of Modern Science

We have investigated the conditions of quantum interferences in hydrocarbons with substituents using density functional theory and tight binding approximation combined with non-equilibrium Green’s function technique. The chosen model systems, namely benzene and tripyridyl–triazine molecules, have elucidated three prominent rules. The ‘first rule’ is the occurrence of inevitable, destructive quantum interference when 1,3-benzene ring incorporates single substituent at the fifth site. The ‘second rule’ is the chaotic occurrence of quantum interferences due the position and/or type of the substituents. The ‘third rule’: the substituents decrease (increase) the probability of destructive (constructive) interferences

Physical-Chemical Characterization And Heavy Metals Assessment Of Waters And Sediments Of Sebou Watershed (Top Sebou, Morocco), Mohamed Kabriti, Eda Mahougnon Léonce, Chaimaa Merbouh, Bensaber Abdelfattah, Abdelmajid Achkir, Abdlhakim Aouragh, Iounes Nadia

Karbala International Journal of Modern Science

The main purpose of this study was to investigate the impact of human activities, geochemical background and seasons on pollutant pathway. Surface water, groundwater and sediments were assessed to highlight and confirm those impacts. Sixteen physico-chemical parameters were measured (T°, pH, O2, salinity, conductivity, BOD5, COD, SM, Cl-, NO2-, NO3-, NH4+, TAC, TH, SO₄²- and PO43-) and twelve metallic trace elements were analyzed (Ar, Cr, Zn, Mn, Ni, Fe, Al, Cd, Cu, Pb, K and Na). Five sampling campaigns were carried out in 18 sampling points for over one year, between July 2018 and July 2019 in the upstream part …

Nanocellulose Sheets From Oil Palm Empty Fruit Bunches Treated With Naoh Solution, Farah Fahma, Faiza Ayu Lestari, Ika Amalia Kartika, Nurmalisa Lisdayana, Evi Savitri Iriani

Karbala International Journal of Modern Science

The objective of this study is to produce nanocellulose sheets from oil palm empty fruit bunches (OPEFBs). Nanocellulose sheets from OPEFBs were prepared through the dewatering process using vacuum filtration. Subsequently, the produced sheets were treated with NaOH solution to improve the mechanical stability of their structure, causing them to be firm in water. The water absorption of nanocellulose sheet increased with increasing NaOH concentrations up to 20 wt%, increasing tensile strength, and Young’s modulus, but decreased when they were treated with 30 wt%. The diameter shrinkage of nanocellulose sheets was directly proportional to the NaOH concentration and soaking time. …

Molecular Structure Vibrational & Electronic Properties Of Some Isatin Derivatives, Fatma K. Fkandermili Prof, Fatma M. Aldibashi S, Hakan S. Sayiner Prof

Karbala International Journal of Modern Science

Abstract

In this study, Natural Bonding Orbitals (NBOs) were applied to isatin, 5‑fluoroisatin, 5‑chloroisatin, 5‑methylisatin and 5‑methoxyisatin using the Lee-Yang-Parr correlation functional B3LYP with 6‑311++G(2d,2p) basis set. Natural bonding analysis was performed to consider the transfer interactions of intra-molecular charge, pre-hybridization and electron density within the isatin, 5‑fluoroisatin, 5‑chloroisatin, 5‑methylisatin and 5‑methoxyisatin. In natural bonding orbital analysis, the wave functions of the electrons were explicated in sets of occupied Lewis type terms, (bonds or lone pairs) and sets of unoccupied non‑Lewis (anti‑bond and Rydberg) localized natural bonding orbitals. The electron density between these orbitals was correlated to stabilize the interaction …

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Beneficial Impacts Of Incorporating The Non-Natural Amino Acid Azulenyl-Alanine Into The Trp-Rich Antimicrobial Peptide Bucathl4b., Areetha R D'Souza, Matthew R Necelis, Alona Kulesha, Gregory A. Caputo, Olga V Makhlynets

College of Science & Mathematics Departmental Research

Antimicrobial peptides (AMPs) present a promising scaffold for the development of potent antimicrobial agents. Substitution of tryptophan by non-natural amino acid Azulenyl-Alanine (AzAla) would allow studying the mechanism of action of AMPs by using unique properties of this amino acid, such as ability to be excited separately from tryptophan in a multi-Trp AMPs and environmental insensitivity. In this work, we investigate the effect of Trp→AzAla substitution in antimicrobial peptide buCATHL4B (contains three Trp side chains). We found that antimicrobial and bactericidal activity of the original peptide was preserved, while cytocompatibility with human cells and proteolytic stability was improved. We envision …

Poly(Pyridinium Salt)S Containing 2,7-Diamino-9,9'-Dioctylfluorene Moieties With Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline And Light-Emitting Properties, Pradip K. Bhowmik, Tae S. Jo, Jung J. Koh, Jongwon Park, Bidyut Biswas, Ronald Carlo G. Principe, Haesook Han, András F. Wacha, Matti Knaapila

Chemistry and Biochemistry Faculty Research

A series of poly(pyridinium salt)s-fluorene main-chain ionic polymers with various organic counterions were synthesized by using ring-transmutation polymerization and metathesis reactions. Their chemical structures were characterized by Fourier Transform Infrared (FTIR), proton (1H), and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers. These polymers showed a number-average molecular weight (Mns) between 96.5 and 107.8 kg/mol and polydispersity index (PDI) in the range of 1.12-1.88. They exhibited fully-grown lyotropic phases in polar protic and aprotic solvents at different critical concentrations. Small-angle X-ray scattering for one polymer example indicates lyotropic structure formation for 60-80% solvent fraction. A lyotropic smectic phase contains 10 …

Mechanical Characteristics Of Cement Paste In The Presence Of Carbon Nanotubes And Silica Oxide Nanoparticles: An Experimental Study, Moses Karakouzian, Visar Farhangi, Marzieh Ramezani Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh

Civil and Environmental Engineering and Construction Faculty Research

Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared using three different portions of MWCNT and NS. …

Pathways To Detection Of Strongly-Bound Inorganic Species: The Vibrational And Rotational Spectral Data Of Alh2oh, Hmgoh, Alh2nh2, And Hmgnh2, Alexandria G. Watrous, Megan C. Davis, Ryan C. Fortenberry

Faculty and Student Publications

Small, inorganic hydrides are likely hiding in plain sight, waiting to be detected toward various astronomical objects. AlH2OH can form in the gas phase via a downhill pathway, and the present, high-level quantum chemical study shows that this molecule exhibits bright infrared features for anharmonic fundamentals in regions above and below that associated with polycyclic aromatic hydrocarbons. AlH2OH along with HMgOH, HMgNH2, and AlH2NH2 are also polar with AlH2OH having a 1.22 D dipole moment. AlH2OH and likely HMgOH have nearly unhindered motion of the hydroxyl group but are still strongly bonded. This could assist in gas phase synthesis, where …

Thermodynamics Of Ligand Binding And Global Structural Stability Of Human Serum Albumin, Matthew Walter Eskew

Dissertations and Theses

Protein structure is integral to its function. For the past 70 years differential scanning calorimetry has been used to measure protein structural stability. More recently it has been used to study macromolecular interactions. Interactions between proteins and ligands can manifest on differential scanning calorimetry melting curves or thermograms. Utilizing differential scanning calorimetry thermograms to detect or diagnose diseases has been a major goal in disease diagnostics. However, correlating specific ligand-protein interactions, as manifested in a thermogram, with a disease-specific plasma thermogram, has proven elusive.

Modified human serum albumin was utilized to develop a process to capture and retrieve ligands from …

Collaborative Research: Development Of A Better Understanding Of Ambient Rm Chemistry, Reactions Forming, And Methods For Measurement, Seth Lyman

Funded Research Records

No abstract provided.

Complex Fluid Dynamics: Chemo-Hydrodynamics Driven By Autocatalytic Reaction Fronts, Matthew Walter Eskew

Dissertations and Theses

Chemo-hydrodynamics generated from reaction-diffusion-convection processes of autocatalytic chemical systems are extensively studied for their applications in modeling complex systems. Compared to the more extensively studied autocatalytic systems, chlorite-tetrathionate and chlorite-trithionate, the chlorite-thiourea systems is relatively unexplored. Compared to the two previous systems, chlorite-thiourea has more straightforward chemical kinetics. To narrow the gap between chlorite-thiourea and the other systems a combination of experimental study and numerical simulation were employed to quantify this system.

Compared to established literature, experiments were performed at five orders of magnitude lower concentration of indicator, minimizing confounding effects of indicator on hydrodynamic motion. To accurately image the …

Denver - Speer Blvd & I-25

United States Data - Colorado

Relevant Publications

Air & Waste Management Association Publication (1996)

Environmental Science & Technology Publication (2000)

1998 Final Report

Denver 6th Ave & I-25

United States Data - Colorado

Relevant Publications

Atmospheric Environment Publication (2002)

Environmental Science & Technology Publication (1997)

Environmental Science & Technology Publication (1998)

Environmental Science & Technology Publication (2003)

Environmental Science & Technology Publication (2006)

Environmental Science & Technology Publication (2008)

Environmental Science & Technology Publication (2014)

Environmental Science & Technology Publication (2015)

Environmental Science & Technology Publication (2021)

1999 Final Report

2000 Final Report

2001 Final Report

2003 Final Report

2005 Final Report

2007 Final Report

2013 Final Report

2017 Final Report

2020 Final Report