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Articles 181 - 210 of 941

Full-Text Articles in Chemistry

Binding Interactions Between Mixed-Monlayer Functionalized Gold Nanoparticles (Aunps) And The Serum Protein Albumin, Jennifer Hanigan-Diebel Jan 2022

Binding Interactions Between Mixed-Monlayer Functionalized Gold Nanoparticles (Aunps) And The Serum Protein Albumin, Jennifer Hanigan-Diebel

All Master's Theses

This study investigated the protein adsorption interactions of bovine serum albumin (BSA) with three different functionalized 5 nm gold nanoparticles (AuNPs) in order to determine the binding affinity and total amount of protein adsorbed to each AuNP surface chemistry. AuNPs were synthesized using two different capping agents to display three different surface chemistries: a neutral ω-functionalized thiol ligand (mercapto-ethoxy-ethoxy-ethanol, MEEE), a thiol ligand that is negatively charged at pH 7.4 (mercaptohexanoic acid, MHA), and a mixture of the two ligands (mixed-ligand AuNPs). The interactions of this library of AuNPs with bovine serum albumin (BSA) were investigated using UV-visible absorbance spectroscopy, …


Purification And Activity Assay Optimization Of Bacterial Catalase From Psychrobacter Koprana, Sydney Willis Jan 2022

Purification And Activity Assay Optimization Of Bacterial Catalase From Psychrobacter Koprana, Sydney Willis

Honors Program Theses

To date, catalase protein from bacterial species is not the most widely used commercial catalase. Catalase, the enzyme that breaks down hydrogen peroxide in most living organisms, is an invaluable enzyme in the food, agriculture, and pharmaceutical industries. In 2019, a novel species of a psychrotolerant bacterium was discovered in Cold Harbor, NY. This species, Psychrobacter koprana, exhibits highly active catalase. Preliminary data from activity assays demonstrates that P. koprana catalase has the same activity as commercially available catalase. After purification and activity assay optimization, the activity of this catalase has the potential to be more active than other easily …


Electrochemical Impedance Spectroscopy Analysis Of Corrosion Of Reinforcing Steel In Fly Ash Mortar By Means Of Transmission Line Modeling, Padraig Stack Jan 2022

Electrochemical Impedance Spectroscopy Analysis Of Corrosion Of Reinforcing Steel In Fly Ash Mortar By Means Of Transmission Line Modeling, Padraig Stack

Williams Honors College, Honors Research Projects

Electrochemical impedance spectroscopy (EIS) is an important non-destructive tool that allows for a deeper understanding of the electrochemical processes and mechanisms occurring in an electrochemical cell. Equivalent electrical circuits (EECs) are used to model the impedance data into electrical components, such as resistors and capacitors, on a circuit. Current potentiostat offers software packages that can analyze the frequency response, but the software only supports “simple” EEC that can be written as fixed electrical components in some combination of series and parallel. Park and Macdonald propose a transmission line model (TLM) that does not use lumped-element models, instead, the values of …


Development Of Peg-B-Pla Based Micelles For Neutralization Of A Toxic Peptide, Giselle Campos Jan 2022

Development Of Peg-B-Pla Based Micelles For Neutralization Of A Toxic Peptide, Giselle Campos

Graduate Theses/Dissertations

I herein report the preparation and characterization of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles as potential “plastic antidotes” for a toxic peptide, melittin. PEG-b-PLA micelles have been used in a number of biomedical applications for their biodegradability and biocompatibility. Along these lines, I investigated the colloidal stability and the peptide absorption properties of PEG-b-PLA/PLA mixed micelles. A series of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles were prepared, and their colloidal stability was studied. The hydrodynamic diameters of stable micelles were determined by using Dynamic …


Advancing Competency In Managing Risk And Knowledge: Steps Toward Operationalisation Of The Risk-Knowledge Infinity Cycle (Rki Cycle) - Part 1: Improving Effectiveness Of Risk-Based Decision Making (Rbdm), Martin Lipa, Paige Kane, Anne Greene Jan 2022

Advancing Competency In Managing Risk And Knowledge: Steps Toward Operationalisation Of The Risk-Knowledge Infinity Cycle (Rki Cycle) - Part 1: Improving Effectiveness Of Risk-Based Decision Making (Rbdm), Martin Lipa, Paige Kane, Anne Greene

Articles

To date, literature on the Risk-Knowledge Infinity Cycle (RKI Cycle) has mainly been theoretical. This paper series intent is to focus on the operationalisation of the RKI Cycle by describing a series of steps – the “How to” – for RKI Cycle deployment, to help move the RKI Cycle from theory to practice. The first paper in this series focuses on how the RKI Cycle can support effective Risk-Based Decision Making (RBDM).


Identifying And Minimizing Sources Of Variability Within Modern Spectroscopic Techniques For The Forensic Analysis Of Glass, Oriana Christy Ovide Jan 2022

Identifying And Minimizing Sources Of Variability Within Modern Spectroscopic Techniques For The Forensic Analysis Of Glass, Oriana Christy Ovide

Graduate Theses, Dissertations, and Problem Reports (ETD)

Broken glass is a trace material frequently found at crime scenes such as hit-and-runs, burglaries, assaults, and homicides. Existing research encompassing the forensic analysis of glass evidence is vast. Published studies cover the analysis and interpretation of various types of glass. However, organizations such as the National Institute of Justice (NIJ), National Institute of Standards and Technology Organization of Scientific Area Committees (NIST-OSAC), and American Society of Trace Evidence Examiners (ASTEE) continue to identify glass-specific research needs to strengthen the scientific foundations of the field. Current gaps within the forensic glass community involve understanding modern glass formulations, re-evaluating the performance …


Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott Jan 2022

Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Forensic science relies on the use of multiple techniques in the assessment of evidence to increase the accuracy and reliability of the results. However, with the rapidly changing drug landscape due to the introduction of novel psychoactive substances, many traditional screening methods are no longer sensitive or selective enough for use. Additionally, many screening methods such as chemical color tests are prone to false positive and negative results and are subjective. Therefore, the goal of this dissertation was to develop a novel analytical scheme that can provide a more efficient, rapid, and sensitive method that will facilitate adoption in the …


Oxidative Damage To Brain Cells Underlies: (I) Resistance To Radiation And Increased Tumor Cell Growth In Glioblastoma; (Ii) Apoe Allele Status And Pentose Phosphate Pathway Proteins In Alzheimer Disease Mouse Models, Nicole Rummel Jan 2022

Oxidative Damage To Brain Cells Underlies: (I) Resistance To Radiation And Increased Tumor Cell Growth In Glioblastoma; (Ii) Apoe Allele Status And Pentose Phosphate Pathway Proteins In Alzheimer Disease Mouse Models, Nicole Rummel

Theses and Dissertations--Chemistry

Oxidative phosphorylation occurs within the inner mitochondrial membrane producing ATP for the cell’s energy needs. The Electron Transport Chain carries out the transfer of electrons from electron carriers through a series of proteins to form a proton gradient across the inner mitochondrial membrane. This gradient acts as the energy source needed to put a phosphate onto ADP and form ATP. With the large amounts of free electrons and oxygen within the mitochondria, an inevitable by-product of free radicals in the form of superoxide are produced. Superoxide (O-̇2) is a reactive radical that can react further to …


Self-Assembly Of Black Cumin Oil-Based Nanoemulsion On Various Surfactants: A Molecular Dynamics Study, Aulia Fikri Hidayat, Taufik Muhammad Fakih Dec 2021

Self-Assembly Of Black Cumin Oil-Based Nanoemulsion On Various Surfactants: A Molecular Dynamics Study, Aulia Fikri Hidayat, Taufik Muhammad Fakih

Makara Journal of Science

Black cumin is commonly used as traditional medicine due to its wide range of pharmacological potential. Black cumin oil (BCO) was often prepared as nanoemulsion to improve its solubility, stability, and bioavailability. This study was conducted to investigate the molecular behavior as well as structural evolution of BCO-surfactant systems during self-assembly micellization using molecular dynamics (MD) simulations. Several BCO constituents and variations of surfactants were employed to model BCO-surfactant systems. 50 ns of MD simulations were performed to elucidate their evolution of structures and physicochemical properties during formation. Results showed that BCO-tween20 and BCO-lecithin were able to form spherical-shaped micelles …


Uniting Non-Empirical And Semi-Empirical Density Functional Approximation Strategies Using Constraint-Based Regularization, Trine K. Quady Dec 2021

Uniting Non-Empirical And Semi-Empirical Density Functional Approximation Strategies Using Constraint-Based Regularization, Trine K. Quady

University Honors Theses

In this work, we present a general framework that unites the two primary strategies for constructing density functional approximations (DFAs): non-empirical (NE) constraint satisfaction and semi-empirical (SE) data-driven optimization. The proposed method employs B-splines--bell-shaped spline functions with compact support--to construct each inhomogeneity correction factor (ICF). This choice offers several distinct advantages over a polynomial basis by enabling explicit enforcement of linear and non-linear constraints as well as ICF smoothness using Tikhonov regularization and penalized B-splines (P-splines). As proof of concept, we use this approach to construct CASE21--a Constrained And Smoothed semi-Empirical global hybrid generalized gradient approximation that completely satisfies all …


Computational Analysis Of The Spin Trapping Properties Of Lipoic Acid And Dihydrolipoic Acid, Matthew Bonfield Dec 2021

Computational Analysis Of The Spin Trapping Properties Of Lipoic Acid And Dihydrolipoic Acid, Matthew Bonfield

Electronic Theses and Dissertations

While the spin trapping properties of thiols have been investigated through EPR analysis and kinetics studies, few groups have studied these properties using strictly computational methods. In particular, α-lipoic acid (ALA) and its reduced form, dihydrolipoic acid (DHLA), one of the strongest endogenously produced antioxidants, show potential for being effective, naturally occurring spin traps for the trapping of reactive oxygen species. This research covers electronic structure calculations of ALA, DHLA, and their corresponding hydroxyl radical spin adducts, performed at the cc-pVDZ/B3LYP/DFT level of theory. The effects on DHLA introduced by other radicals such as ·OOH, ·OCH3, …


Amilorides Inhibit Sars-Cov-2 Replication In Vitro By Targeting Rna Structures, Martina Zafferani, Christina Haddad, Le Luo, Jesse Davila-Calderon, Liang-Yuan Chiu, Christian Shema Mugisha, Adeline G. Monaghan, Andrew A. Kennedy, Joseph D. Yesselman, Robert J. Gifford, Andrew W. Tai, Sebla B. Kutluay, Mei-Ling Li, Gary Brewer, Blanton S. Tolbert, Amanda E. Hargrove Nov 2021

Amilorides Inhibit Sars-Cov-2 Replication In Vitro By Targeting Rna Structures, Martina Zafferani, Christina Haddad, Le Luo, Jesse Davila-Calderon, Liang-Yuan Chiu, Christian Shema Mugisha, Adeline G. Monaghan, Andrew A. Kennedy, Joseph D. Yesselman, Robert J. Gifford, Andrew W. Tai, Sebla B. Kutluay, Mei-Ling Li, Gary Brewer, Blanton S. Tolbert, Amanda E. Hargrove

Department of Chemistry: Faculty Publications

The SARS-CoV-2 pandemic, and the likelihood of future coronavirus pandemics, emphasized the urgent need for development of novel antivirals. Small-molecule chemical probes offer both to reveal aspects of virus replication and to serve as leads for antiviral therapeutic development. Here, we report on the identification of amiloride-based small molecules that potently inhibit OC43 and SARS-CoV-2 replication through targeting of conserved structured elements within the viral 5′-end. Nuclear magnetic resonance–based structural studies revealed specific amiloride interactions with stem loops containing bulge like structures and were predicted to be strongly bound by the lead amilorides in retrospective docking studies. Amilorides represent the …


Nuscon: A Community-Driven Platform For Quantitative Evaluation Of Nonuniform Sampling In Nmr, Yulia Pustovalova, Frank Delaglio, D. Levi Craft, Haribabu Arthanari, Ad Bax, Martin Billeter, Mark J. Bostock, Hesam Dashti, D. Flemming Hansen, Sven G. Hyberts, Bruce A. Johnson, Krzysztof Kazimierczuk, Hengfa Lu, Mark Maciejewski, Tomas M. Miljenović, Mehdi Mobli, Daniel Nietlispach, Vladislav Orekhov, Robert Powers, Xiaobo Qu, Scott Anthony Robson, David Rovnyak, Gerhard Wagner, Jinfa Ying, Matthew Zambrello, Jeffrey C. Hoch, David L. Donoho, Adam D. Schuyler Nov 2021

Nuscon: A Community-Driven Platform For Quantitative Evaluation Of Nonuniform Sampling In Nmr, Yulia Pustovalova, Frank Delaglio, D. Levi Craft, Haribabu Arthanari, Ad Bax, Martin Billeter, Mark J. Bostock, Hesam Dashti, D. Flemming Hansen, Sven G. Hyberts, Bruce A. Johnson, Krzysztof Kazimierczuk, Hengfa Lu, Mark Maciejewski, Tomas M. Miljenović, Mehdi Mobli, Daniel Nietlispach, Vladislav Orekhov, Robert Powers, Xiaobo Qu, Scott Anthony Robson, David Rovnyak, Gerhard Wagner, Jinfa Ying, Matthew Zambrello, Jeffrey C. Hoch, David L. Donoho, Adam D. Schuyler

Department of Chemistry: Faculty Publications

Although the concepts of nonuniform sampling (NUS) and non-Fourier spectral reconstruction in multidimensional NMR began to emerge 4 decades ago (Bodenhausen and Ernst, 1981; Barna and Laue, 1987), it is only relatively recently that NUS has become more commonplace. Advantages of NUS include the ability to tailor experiments to reduce data collection time and to improve spectral quality, whether through detection of closely spaced peaks (i.e., “resolution”) or peaks of weak intensity (i.e., “sensitivity”). Wider adoption of these methods is the result of improvements in computational performance, a growing abundance and flexibility of software, support from NMR spectrometer vendors, and …


Functional Inks And Indicators For Smart Tag Based Intelligent Packaging Applications, Liisa Hakola, Kaisa Vehmas, Maria Smolander Nov 2021

Functional Inks And Indicators For Smart Tag Based Intelligent Packaging Applications, Liisa Hakola, Kaisa Vehmas, Maria Smolander

Journal of Applied Packaging Research

Smart Tags are functional, information transmitting elements that combine 2D barcodes and environmental sensing into a cost effective tag that can be attached to e.g. product packages, where additional elements should not increase the product costs significantly. Important feature of these Smart Tags is that they can be attached to products in very high-speed production lines, which makes them suitable to fast moving consumer goods. Because the Smart Tags are sensitive to environmental conditions, they are dynamic, but they also enable context aware services as each of them can be unique. The enabling technologies behind these Smart Tags are i) …


Electro-Organic Synthesis Of Schiff-Bases And Azo-Schiff Bases By Electrochemical Reduction Of The Nitro Group Group In Different Media, Siba Naseef, Deep Bakair, Rushdi Mador Nov 2021

Electro-Organic Synthesis Of Schiff-Bases And Azo-Schiff Bases By Electrochemical Reduction Of The Nitro Group Group In Different Media, Siba Naseef, Deep Bakair, Rushdi Mador

Hadhramout University Journal of Natural & Applied Sciences

In this research synthesized amino is derivative of Schiff-bases by using electrolysis cell. Electrochemical reduction of para-nitroaniline and electrocatalysed condensation have been carried out at zinc electrode and anode from coal in the presence of potassium chloride as supporting electrolyte in water/methanol solution, and in the application of 20V voltage, where interaction is in two stages: the first stage involves the electrochemical reduction of nitro group and get the amino and the second phase also, azo Schiff was synthesized between para-nitroaniline and metoxybenzealdehyde by electrolysis method, which was supplied with a zinc electrode as cathode to perform electrochemical reduction in …


A Nosy Neighbor: Purification And Functional Characterization Of Lpg2149, Ashley M. Holahan Oct 2021

A Nosy Neighbor: Purification And Functional Characterization Of Lpg2149, Ashley M. Holahan

The Journal of Purdue Undergraduate Research

Ubiquitination is a process that marks proteins for various cell-signaling pathways, namely protein degradation and other processes. Th ese pathways are essential in a wide array of cellular processes, including defense mechanisms against invading pathogens. Th e ubiquitination process is universally found in all eukaryotic organisms, including plants and animals, and thus plays a vital role in cellular homeostasis. Recently, more discoveries have been made on prokaryotic effector proteins that hijack the ubiquitination system even when they do not possess a ubiquitin system of their own. MavC, also known as lpg2147 (Gan, Nakayasu, Hollenbeck, & Luo, 2019; Puvar et al., …


Bioadhesives, Mark Alan Helle, Chin Li Cheung Oct 2021

Bioadhesives, Mark Alan Helle, Chin Li Cheung

Department of Chemistry: Faculty Publications

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


Lateral Growth Of Xenon Hydrate Films On Mica, Avinash Kumar Both, Chin Li Cheung Oct 2021

Lateral Growth Of Xenon Hydrate Films On Mica, Avinash Kumar Both, Chin Li Cheung

Department of Chemistry: Faculty Publications

In this paper, we report an in situ optical microscopy study of lateral growth of xenon (Xe) hydrate thin films on mica at sub-zero temperatures. The interactions between a solid surface and water molecules can strongly affect the alignment of water molecules and induce ice-like ordered structures within the water layer at the water-surface interface. Mica was chosen as a model surface to study the surface effect of hydrophilic sheet silicates on the lateral growth of Xe hydrate films. Under the experimental conditions, the lateral growth of Xe hydrate films was measured to be at an average rapid rate of …


National Chemistry Week: From Irl To The Web, Ilayda Kelley, Daniela Mesa Sanchez Oct 2021

National Chemistry Week: From Irl To The Web, Ilayda Kelley, Daniela Mesa Sanchez

Purdue Journal of Service-Learning and International Engagement

National Chemistry Week, an outreach program initiated by the American Chemical Society (ACS), encourages scientists to bring their love of chemistry to their community. Celebrated nationwide, ACS invites businesses, schools, and individuals to organize and participate in community events to promote the value of chemistry in everyday life. The Purdue graduate student chapter of Iota Sigma Pi, a national honor society for women in chemistry, annually organizes one such celebration. On a normal year, this event is a large logistical undertaking in which 100+ volunteers go directly to over 70 local elementary school classrooms and perform a series of activities …


Cyclic Peptide-Gadolinium Nanocomplexes As Sirna Delivery Tools, Amir Nasrolahi Shirazi, Muhammad Imran Sajid, Dindyal Mandal, David Stickley, Stephanie Nagasawa, Joshua Long, Sandeep Lohan, Keykavous Parang, Rakesh Kumar Tiwari Oct 2021

Cyclic Peptide-Gadolinium Nanocomplexes As Sirna Delivery Tools, Amir Nasrolahi Shirazi, Muhammad Imran Sajid, Dindyal Mandal, David Stickley, Stephanie Nagasawa, Joshua Long, Sandeep Lohan, Keykavous Parang, Rakesh Kumar Tiwari

Pharmacy Faculty Articles and Research

We have recently reported that a cyclic peptide containing five tryptophan, five arginine, and one cysteine amino acids [(WR)5C], was able to produce peptide-capped gadolinium nanoparticles, [(WR)5C]-GdNPs, in the range of 240 to 260 nm upon mixing with an aqueous solution of GdCl3. Herein, we report [(WR)5C]-GdNPs as an efficient siRNA delivery system. The peptide-based gadolinium nanoparticles (50 µM) did not exhibit significant cytotoxicity (~93% cell viability at 50 µM) in human leukemia T lymphoblast cells (CCRF-CEM) and triple-negative breast cancer cells (MDA-MB-231) after 48 h. Fluorescence-activated cell sorting (FACS) analysis indicated …


Hemoglobin-Modified Core–Shell Fe3o4@Au Nanostructures For The Electrochemical Detection Of Acrylamide, Endang Saepudin, Tri Yuliani, Mochammad Arfin Fardiansyah Nasution, Munawar Khalil, Jong Wook Hong, Tribidasari Anggraningrum Ivandini Sep 2021

Hemoglobin-Modified Core–Shell Fe3o4@Au Nanostructures For The Electrochemical Detection Of Acrylamide, Endang Saepudin, Tri Yuliani, Mochammad Arfin Fardiansyah Nasution, Munawar Khalil, Jong Wook Hong, Tribidasari Anggraningrum Ivandini

Makara Journal of Science

In this study, electrochemical detection of acrylamide using hemoglobin (Hb)-modified core–shell Fe3O4@Au nanostructures was conducted. Fe3O4 nanoparticles (~4.9 nm) and core–shell Fe3O4@Au (5.0–6.4 nm) nanostructures were successfully synthesized by the thermal decomposition method. Electrochemical investigation revealed that the optimum amount of Hb of 2 mg/mL could be immobilized in 0.1 M acetate buffer solution (pH = 6). Moreover, the detection of acrylamide using Fe3O4@Au/Hb was evaluated by the cyclic voltammetry technique. A linear calibration curve (R2 = 0.98) in the concentration range of …


Oxidation Alters The Architecture Of The Phenylalanyl-Trna Synthetase Editing Domain To Confer Hyperaccuracy, Pooja Srinivas, Rebecca E. Steiner, Ian J. Pavelich, Ricardo Guerrera-Ferreira, Puneet Juneja, Michael Ibba, Christine M. Dunham Sep 2021

Oxidation Alters The Architecture Of The Phenylalanyl-Trna Synthetase Editing Domain To Confer Hyperaccuracy, Pooja Srinivas, Rebecca E. Steiner, Ian J. Pavelich, Ricardo Guerrera-Ferreira, Puneet Juneja, Michael Ibba, Christine M. Dunham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

High fidelity during protein synthesis is accomplished by aminoacyl-tRNA synthetases (aaRSs). These enzymes ligate an amino acid to a cognate tRNA and have proofreading and editing capabilities that ensure high fidelity. Phenylalanyl-tRNA synthetase (PheRS) preferentially ligates a phenylalanine to a tRNAPhe over the chemically similar tyrosine, which differs from phenylalanine by a single hydroxyl group. In bacteria that undergo exposure to oxidative stress such as Salmonella enterica serovar Typhimurium, tyrosine isomer levels increase due to phenylalanine oxidation. Several residues are oxidized in PheRS and contribute to hyperactive editing, including against mischarged Tyr-tRNAPhe, despite these oxidized residues not …


Effects Of Fluoride On Submandibular Glands Of Mice: Changes In Oxidative Biochemistry, Proteomic Profile, And Genotoxicity, Leidiane Alencar De Oliveira Lima, Giza Hellen Nonato Miranda, Walessa Alana Bragança Aragão, Leonardo Oliveira Bittencourt, Sávio Monteiro Dos Santos, Michel Platini Caldas De Souza, Lygia S. Nogueira, Edivaldo Herculano Corrêa De Oliveira, Marta Chagas Monteiro, Aline Dionizio, Aline Lima Leite, Juliano Pelim Pessan, Marília Afonso Rabelo Buzalaf, Rafael Rodrigues Lima Sep 2021

Effects Of Fluoride On Submandibular Glands Of Mice: Changes In Oxidative Biochemistry, Proteomic Profile, And Genotoxicity, Leidiane Alencar De Oliveira Lima, Giza Hellen Nonato Miranda, Walessa Alana Bragança Aragão, Leonardo Oliveira Bittencourt, Sávio Monteiro Dos Santos, Michel Platini Caldas De Souza, Lygia S. Nogueira, Edivaldo Herculano Corrêa De Oliveira, Marta Chagas Monteiro, Aline Dionizio, Aline Lima Leite, Juliano Pelim Pessan, Marília Afonso Rabelo Buzalaf, Rafael Rodrigues Lima

Department of Chemistry: Faculty Publications

Although fluoride (F) is well-known to prevent dental caries, changes in cell processes in different tissues have been associated with its excessive exposure. Thus, this study aimed to evaluate the effects of F exposure on biochemical, proteomic, and genotoxic parameters of submandibular glands. Twenty one old rats (n = 30) were allocated into three groups: 60 days administration of drinking water containing 10 mgF/L, 50 mgF/L, or only deionized water (control). The submandibular glands were collected for oxidative biochemistry, protein expression profile, and genotoxic potential analyses. The results showed that both F concentrations increased the levels of thiobarbituric acid–reactive …


Atomistic Simulations And In Silico Mutational Profiling Of Protein Stability And Binding In The Sars-Cov-2 Spike Protein Complexes With Nanobodies: Molecular Determinants Of Mutational Escape Mechanisms, Gennady M. Verkhivker, Steve Agajanian, Deniz Yasar Oztas, Grace Gupta Sep 2021

Atomistic Simulations And In Silico Mutational Profiling Of Protein Stability And Binding In The Sars-Cov-2 Spike Protein Complexes With Nanobodies: Molecular Determinants Of Mutational Escape Mechanisms, Gennady M. Verkhivker, Steve Agajanian, Deniz Yasar Oztas, Grace Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

Structure-functional studies have recently revealed a spectrum of diverse high-affinity nanobodies with efficient neutralizing capacity against SARS-CoV-2 virus and resilience against mutational escape. In this study, we combine atomistic simulations with the ensemble-based mutational profiling of binding for the SARS-CoV-2 S-RBD complexes with a wide range of nanobodies to identify dynamic and binding affinity fingerprints and characterize the energetic determinants of nanobody-escaping mutations. Using an in silico mutational profiling approach for probing the protein stability and binding, we examine dynamics and energetics of the SARS-CoV-2 complexes with single nanobodies Nb6 and Nb20, VHH E, a pair combination VHH E + …


Inelastic, Exchange, And Reactive Processes In Rovibrationally Excited Collisions Of Hd With H, Boyi Zhou, Benhui Yang, Balakrishnan Naduvalath, B. K. Kendrick, Maodu Chen, P. C. Stancil Sep 2021

Inelastic, Exchange, And Reactive Processes In Rovibrationally Excited Collisions Of Hd With H, Boyi Zhou, Benhui Yang, Balakrishnan Naduvalath, B. K. Kendrick, Maodu Chen, P. C. Stancil

Chemistry and Biochemistry Faculty Research

The HD molecule is an important coolant in early universe chemistry models and a tracer of H2 in star-forming regions. Rate coefficients for collisional excitation and de-excitation of HD rotational and vibrational levels form important ingredients in astrophysical models. While collisions with He, H2, and H are the most important, available data for H + HD collisions are largely limited to temperatures less than 1000 K for the vibrational ground state, low-lying rotational levels of the v = 1 HD vibrational level, or computed without reactive contributions. Here, through explicit quantum scattering calculations, we report extensive data for rovibrational transitions …


Emergence Of Non-Hexagonal Crystal Packing Of Deswollen And Deformed Ultra-Soft Microgels Under Osmotic Pressure Control, Molla R. Islam, Rachel Nguyen, L. Andrew Lyon Sep 2021

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

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

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


An Examination Of Factors Influencing Small Proton Chemical Shift Differences In Nitrogen-Substituted Monodeuterated Methyl Groups, Stuart J. Elliott, O. Maduka Ogba, Lynda J. Brown, Daniel J. O'Leary Sep 2021

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

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

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


Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk Sep 2021

Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk

Dissertations, Theses, and Capstone Projects

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism …


Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski Sep 2021

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

Dissertations, Theses, and Capstone Projects

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


Sources And Aftermaths Of Pipeline Related Leaks And Spills, Justin Smith Aug 2021

Sources And Aftermaths Of Pipeline Related Leaks And Spills, Justin Smith

Symposium of Student Scholars

The escape of oil and other hazardous materials have been shown to pollute and destroy ecosystems. As an aspiring chemist, I am adamant about the secure handling and transportation of oil and other hazardous materials. In the past, researchers have concentrated on oil’s high viscosity. Oil’s high viscosity physically smothers wildlife, affecting their ability to continue critical functions such as respiration, feeding, and thermoregulation. My research focuses on the source of these oil spills, as well as natural gas leaks, for the purpose of risk assessment. In addition, I compare recovery efforts based on the cause of the leak/spill, the …