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Full-Text Articles in Chemistry

Statistical Measurements Of Dispersion Measure Fluctuations Of Frbs, Siyao Xu, David H. Weinberg, Bing Zhang Nov 2021

Statistical Measurements Of Dispersion Measure Fluctuations Of Frbs, Siyao Xu, David H. Weinberg, Bing Zhang

Physics & Astronomy Faculty Research

Extragalactic fast radio bursts (FRBs) have large dispersion measures (DMs) and are unique probes of intergalactic electron density fluctuations. By using the recently released First CHIME/FRB Catalog, we reexamined the structure function (SF) of DM fluctuations. It shows a large DM fluctuation similar to that previously reported in Xu & Zhang, but no clear correlation hinting toward large-scale turbulence is reproduced with this larger sample. To suppress the distortion effect from FRB distances and their host DMs, we focus on a subset of CHIME catalog with DM < 500 pc cm-3. A trend of nonconstant SF and nonzero correlation function (CF) at angular separations θ less than 10 is seen, but with large statistical uncertainties. The difference found between SF and that derived from CF at θ ≲ 10 can be ascribed to the large statistical uncertainties or the density inhomogeneities on scales on the order of 100 Mpc. The possible correlation of electron density fluctuations and inhomogeneities of density distribution should be tested when several thousands of FRBs are available.


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 …


Designing Environmentally Responsible And Highly Effective Bioorthogonally Functionalized Chiral Mri Contrast Agents, Karley Breann Maier Nov 2021

Designing Environmentally Responsible And Highly Effective Bioorthogonally Functionalized Chiral Mri Contrast Agents, Karley Breann Maier

Dissertations and Theses

Magnetic resonance imaging (MRI) revolutionized diagnostic imaging and modernized the characterization of numerous diseases. The clinical success of MRI is in large part due to the employment of gadolinium-based contrast agents (GBCAs). Due to sensitivity limitations, GBCAs are indicated at markedly high dosages (~1 g Gd3+ per exam). The routine use of such large quantities of gadolinium poses significant health and environmental risks. There are growing concerns over the effects of dechelation of the metal in vivo and the possible effect of resulting gadolinium deposition. Concurrently, there is a rising awareness of gadolinium anomalies borne by GBCAs which undergo …


Aberrant Crosstalk Between Insulin Signaling And Mtor In Young Down Syndrome Individuals Revealed By Neuronal-Derived Extracellular Vesicles, Marzia Perluigi, Anna Picca, Elita Montanari, Riccardo Calvani, Federico Marini, Roberto Matassa, Antonella Tramutola, Alberto Villani, Giuseppe Familiari, Fabio Di Domenico, D. Allan Butterfield, Kenneth J. Oh, Emanuele Marzetti, Diletta Valentini, Eugenio Barone Nov 2021

Aberrant Crosstalk Between Insulin Signaling And Mtor In Young Down Syndrome Individuals Revealed By Neuronal-Derived Extracellular Vesicles, Marzia Perluigi, Anna Picca, Elita Montanari, Riccardo Calvani, Federico Marini, Roberto Matassa, Antonella Tramutola, Alberto Villani, Giuseppe Familiari, Fabio Di Domenico, D. Allan Butterfield, Kenneth J. Oh, Emanuele Marzetti, Diletta Valentini, Eugenio Barone

Chemistry Faculty Publications

INTRODUCTION: Intellectual disability, accelerated aging, and early-onset Alzheimer-like neurodegeneration are key brain pathological features of Down syndrome (DS). Although growing research aims at the identification of molecular pathways underlying the aging trajectory of DS population, data on infants and adolescents with DS are missing.

METHODS: Neuronal-derived extracellular vesicles (nEVs) were isolated form healthy donors (HDs, n = 17) and DS children (n = 18) from 2 to 17 years of age and nEV content was interrogated for markers of insulin/mTOR pathways.

RESULTS: nEVs isolated from DS children were characterized by a significant increase in pIRS1Ser636, a marker of …


Synthesis And Styrene Copolymerization Of Octyl 2-Cyano-3-(R-Phenyl)-2-Propenoates, Martin S. Wasilewski Nov 2021

Synthesis And Styrene Copolymerization Of Octyl 2-Cyano-3-(R-Phenyl)-2-Propenoates, Martin S. Wasilewski

College of Science and Health Theses and Dissertations

Novel alkyl ring-substituted octyl phenylcyanoacrylates (OPCA), RPhCH=C(CN)CO2CH2(CH2)6CH3, where R is H, 2-methyl, 3-methyl, 4-methyl, 4-ethyl, 4-propyl, 4-i-propyl, 4-butyl, 4-t-butyl, 4-i-butyl) were prepared and copolymerized with styrene. The ethylenes were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and octyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C NMR. All the ethylenes were copolymerized with styrene in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis. Compositions of ST-OPCA copolymers ranged from 18.6 % to 27.4% of …


Characterization Of Ovarian Cancer-Derived Extracellular Vesicles By Surface-Enhanced Raman Spectroscopy., Nina M. Culum, Tyler T. Cooper, Gilles A. Lajoie, Thamara Dayarathna, Stephen H. Pasternak, Jiahui Liu, Yangxin Fu, Francois Lagugne-Labarthet, Lynne Marie Postovit Nov 2021

Characterization Of Ovarian Cancer-Derived Extracellular Vesicles By Surface-Enhanced Raman Spectroscopy., Nina M. Culum, Tyler T. Cooper, Gilles A. Lajoie, Thamara Dayarathna, Stephen H. Pasternak, Jiahui Liu, Yangxin Fu, Francois Lagugne-Labarthet, Lynne Marie Postovit

Chemistry Publications

Ovarian cancer is the most lethal gynecological malignancy, owing to the fact that most cases are diagnosed at a late stage. To improve prognosis and reduce mortality, we must develop methods for the early diagnosis of ovarian cancer. A step towards early and non-invasive cancer diagnosis is through the utilization of extracellular vesicles (EVs), which are nanoscale, membrane-bound vesicles that contain proteins and genetic material reflective of their parent cell. Thus, EVs secreted by cancer cells can be thought of as cancer biomarkers. In this paper, we present gold nanohole arrays for the capture of ovarian cancer (OvCa)-derived EVs and …


Synthesis And Characterization Of Pyridine-Based Diimide Ligands And Metal Phosphonate Coordination Polymers, Juan L. Pinedo Nov 2021

Synthesis And Characterization Of Pyridine-Based Diimide Ligands And Metal Phosphonate Coordination Polymers, Juan L. Pinedo

Honors Program Theses and Research Projects

Coordination polymers have been a topic of interest because of the large variety of applications these materials have. in particular Metal-Organic Frameworks (MOFs) have been researched due to their porosity and simple synthetic pathways. Structurally a MOF is composed of one or more organic ligands serving as the backbone of the structure. These ligands are complexed with metal ions coordinating into the desired structure. It is this structure that gives way to a variable porosity useful for proton conductivity and material transport. By varying backbone size a framework can be customized for use in specific conditions. This is due not …


Piezoelectric Signals In Vascularized Bone Regeneration, Delfo D’Alessandro, Claudio Ricci, Mario Milazzo, Giovanna Strangis, Francesca Forli, Gabriele Buda, Mario Petrini, Stefano Berrettini, M. Jasim Uddin, Serena Danti, Paolo Parchi Nov 2021

Piezoelectric Signals In Vascularized Bone Regeneration, Delfo D’Alessandro, Claudio Ricci, Mario Milazzo, Giovanna Strangis, Francesca Forli, Gabriele Buda, Mario Petrini, Stefano Berrettini, M. Jasim Uddin, Serena Danti, Paolo Parchi

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The demand for bone substitutes is increasing in Western countries. Bone graft substitutes aim to provide reconstructive surgeons with off-the-shelf alternatives to the natural bone taken from humans or animal species. Under the tissue engineering paradigm, biomaterial scaffolds can be designed by incorporating bone stem cells to decrease the disadvantages of traditional tissue grafts. However, the effective clinical application of tissue-engineered bone is limited by insufficient neovascularization. As bone is a highly vascularized tissue, new strategies to promote both osteogenesis and vasculogenesis within the scaffolds need to be considered for a successful regeneration. It has been demonstrated that bone and …


Premade Nanoparticle Films For The Synthesis Of Vertically Aligned Carbon Nanotubes, Abdul Hoque, Ahamed Ullah, Beth S. Guiton, Noe T. Alvarez Nov 2021

Premade Nanoparticle Films For The Synthesis Of Vertically Aligned Carbon Nanotubes, Abdul Hoque, Ahamed Ullah, Beth S. Guiton, Noe T. Alvarez

Chemistry Faculty Publications

Carbon nanotubes (CNTs) offer unique properties that have the potential to address multiple issues in industry and material sciences. Although many synthesis methods have been developed, it remains difficult to control CNT characteristics. Here, with the goal of achieving such control, we report a bottom-up process for CNT synthesis in which monolayers of premade aluminum oxide (Al2O3) and iron oxide (Fe3O4) nanoparticles were anchored on a flat silicon oxide (SiO2) substrate. The nanoparticle dispersion and monolayer assembly of the oleic-acid-stabilized Al2O3 nanoparticles were achieved using 11-phosphonoundecanoic acid …


A Chemical Mineralogy Study Of ‎The Pad Laba Rocks And The Amber ‎Formation In Al-Basit, North- ‎Western Syria, Mahmoud Qoujah Nov 2021

A Chemical Mineralogy Study Of ‎The Pad Laba Rocks And The Amber ‎Formation In Al-Basit, North- ‎Western Syria, Mahmoud Qoujah

Jerash for Research and Studies Journal مجلة جرش للبحوث والدراسات

The aim of this research is to investigate pillow - lava rocks and amper formation, which located ‎in the top of Syrian ophiolite complex. We test about (50) chemical and mineralogical analyses, ‎to find out the concentration, type, and the distribution of these metals and minerals, in the ‎Bassit region in Latakia. This study help to define the petrogenesis of ambers and he's ‎relationship with upper pillow - lava, we thought that amber was formed by the result of some ‎reasons such destruc tion of pillow - lava, or the result of reaction of lava with seawater, or ‎hydrothermal activity …


Corrosion Prevention On Aluminum Alloy, Andrea Brenner Nov 2021

Corrosion Prevention On Aluminum Alloy, Andrea Brenner

Symposium of Student Scholars

Aluminum alloy (Al-alloy) is a widely used metal in construction, aerospace, aviation, and other necessary fields due to its lightweight and tweakable properties. However, corrosion is inevitable on metals and alloys, and that causes millions of dollars of revenue loss every year. Therefore, we propose to research fabricating coating to prevent corrosion on Al-alloy. This study uses an iron-based metal-organic framework (MOF) and polyurethane (PU) based composite coating to prevent corrosion on the Al-alloy. The makeup of the composite material is changed by varying the percentage of MOF. In addition, a binder is also used to enhance the homogenization between …


Molecular Dynamics Simulations Of Vibrational Infrared And Raman Spectra Of H5o2+, Oluwaseun Omodemi, Ivonne Meares, Gabriella Garofalo, Martina Kaledin Nov 2021

Molecular Dynamics Simulations Of Vibrational Infrared And Raman Spectra Of H5o2+, Oluwaseun Omodemi, Ivonne Meares, Gabriella Garofalo, Martina Kaledin

Symposium of Student Scholars

We report infrared (IR) and Raman vibrational spectra of H5O2+ protonated water dimer using computational chemistry methods, the normal mode analysis (NMA), and molecular dynamics (MD) simulations. Various computational methods and basis sets were used. We also located the H5O2+ stationary points on the potential energy surface using the Gaussian 16 program. The H5O2+ Zundel complex serves as a benchmark system to study the proton transfer process. We also investigated IR and Raman intensities of other deuterated analogs, such as D5O2+, D4 …


Impact Of The Water Content In The Therapeutic Deep Eutectic Solvents, Noam Lewit, James Stewart, Oluseyi Olawuyi, Mohammed A. Halim Nov 2021

Impact Of The Water Content In The Therapeutic Deep Eutectic Solvents, Noam Lewit, James Stewart, Oluseyi Olawuyi, Mohammed A. Halim

Symposium of Student Scholars

Deep eutectic solvent(s) (DES) are the new generation of greener and more sustainable solvents, formulated by the complex of hydrogen bond in the molecules. The solvents allow us to achieve a significantly lower freezing point compared to its components, an affordable formulation and a technology that is typically formulated to improve the bioavailability of a drug. In this research project, we synthesized an ibuprofen-menthol based therapeutic deep eutectic solvent and investigated how water content affects the structure and dynamics of the solvent. For synthesizing the ibuprofen-menthol DES, 2.0629 g of Ibuprofen and 4.6881 g of menthol were placed in a …


Analysis Of Kavalactones In Various Consumptive Kava Samples Using Gc-Ms, Stephanie O'Kon Nov 2021

Analysis Of Kavalactones In Various Consumptive Kava Samples Using Gc-Ms, Stephanie O'Kon

Symposium of Student Scholars

Piper Methysticum, or Kava, is a plant native to the Pacific Islands and is used in various ceremonial and cultural aspects. In the United States, Kava has many dietary forms from sleep aids to mood boosters. The active ingredients found in Kava roots, kavalactones, give users psychoactive effects. However, there are concerns regarding toxicity and unknown safety consumption limits. There are six major kavalactones, and possibly more that have been reported, but not fully researched. The one of interest in this study is kavain. Different solvents, diethyl ether and acetone, have been used in extracting kavalactones from cut kava root. …


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) …


Me3al-Mediated Domino Nucleophilic Addition/Intramolecular Cyclisation Of 2-(2-Oxo-2-Phenylethyl)Benzonitriles With Amines; A Convenient Approach For The Synthesis Of Substituted 1-Aminoisoquinolines, Krishna M. S. Adusumalli, Lakshmi N.S. Konidena, Hima B. Gandham, Krishnaiah Kumari, Krishan R. Valluru, Satya K.R. Nidasanametla, Venkateswara R. Battula, Hari K. Namballa Nov 2021

Me3al-Mediated Domino Nucleophilic Addition/Intramolecular Cyclisation Of 2-(2-Oxo-2-Phenylethyl)Benzonitriles With Amines; A Convenient Approach For The Synthesis Of Substituted 1-Aminoisoquinolines, Krishna M. S. Adusumalli, Lakshmi N.S. Konidena, Hima B. Gandham, Krishnaiah Kumari, Krishan R. Valluru, Satya K.R. Nidasanametla, Venkateswara R. Battula, Hari K. Namballa

Publications and Research

A simple and efficient protocol for the construction of 1-aminoisoquinolines was achieved by treating 2-(2-oxo-2- phenylethyl)benzonitriles with amines in the presence of Me 3 Al. The reaction proceeds via a domino nucleophilic addition with subsequent intramolecular cyclisation. This method provides a wide variety of substituted 1-aminoisoquinolines with good func- tional group tolerance. Furthermore, the synthetic utility of this protocol was demonstrated in the successful synthesis of the anti- tumor agent CWJ-a-5 in gram scale.


3-Dimensional Structural Determination Of Epidermal Growth Factor-Like Repeat 27 From Mouse Notch1 Using Nuclear Magnetic Resonance Spectroscopy, Justin Grennell Nov 2021

3-Dimensional Structural Determination Of Epidermal Growth Factor-Like Repeat 27 From Mouse Notch1 Using Nuclear Magnetic Resonance Spectroscopy, Justin Grennell

LSU Doctoral Dissertations

NOTCH1 has been associated with a variety of human ailments, such as cancer and heart disease. NOTCH1 is a transmembrane protein that contains 36 epidermal growth factor-like (EGF) repeats, which facilitate cell signaling by binding proteins on neighboring cells. Each repeat contains about 40 amino acids and has to be folded in a specific manner to function properly. The amino acid sequence, carbohydrate pattern, and calcium-binding sites of EGF-like repeats vary, but the pattern along the 36-repeat chain is conserved. The Abruptex region (EGF24-29) of NOTCH1 is a highly glycosylated (having undergone sugar addition) and flexible region, which gained its …


Discovery Of Imidazole-Based Inhibitors Of Plasmodium Falciparum Cgmp-Dependent Protein Kinase, Rammohan R. Yadav Bheemanaboina, Mariana Laureano De Souza, Mariana Lozano Gonzalez, Shams Ul Mahmood, Tyler Eck, Tamara Kreiss, Samantha O. Aylor, Alison Roth, Patricia Lee, Brandon S. Pybus, Dennis J. Colussi, Wayne E. Childers, John Gordon, John J. Siekierka, Purnima Bhanot, David P. Rotella Nov 2021

Discovery Of Imidazole-Based Inhibitors Of Plasmodium Falciparum Cgmp-Dependent Protein Kinase, Rammohan R. Yadav Bheemanaboina, Mariana Laureano De Souza, Mariana Lozano Gonzalez, Shams Ul Mahmood, Tyler Eck, Tamara Kreiss, Samantha O. Aylor, Alison Roth, Patricia Lee, Brandon S. Pybus, Dennis J. Colussi, Wayne E. Childers, John Gordon, John J. Siekierka, Purnima Bhanot, David P. Rotella

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The discovery of new targets for the treatment of malaria, in particular those aimed at the pre-erythrocytic stage in the life cycle, advanced with the demonstration that orally administered inhibitors of Plasmodium falciparum cGMP-dependent protein kinase (PfPKG) could clear infection in a murine model. This enthusiasm was tempered by unsatisfactory safety and/or pharmacokinetic issues found with these chemotypes. To address the urgent need for new scaffolds, this paper presents initial structure–activity relationships in an imidazole scaffold at four positions, representative in vitro ADME, hERG characterization, and cell-based antiparasitic activity. This series of PfPKG inhibitors has good in vitro PfPKG potency, …


Molecular Design Of Polymer Coatings Capable Of Photo-Triggered Stress Relaxation Via Dynamic Covalent Bond Exchange, Autumn M. Mineo, Maren E. Buck, Reika Katsumata Nov 2021

Molecular Design Of Polymer Coatings Capable Of Photo-Triggered Stress Relaxation Via Dynamic Covalent Bond Exchange, Autumn M. Mineo, Maren E. Buck, Reika Katsumata

Chemistry: Faculty Publications

Polymer coatings are frequently used to modify surface properties of inorganic substrates. However, the disparity in physical properties between polymer film and substrate often leads to residual stress development, which can be deleterious to the overall performance of coated materials. This work reports the molecular design of polymer films that dissipate stress upon irradiation with ultraviolet (UV) light. These polymers are synthesized by post-polymerization modification of the reactive polymer, poly(2-vinyl-4,4-dimethyl azlactone), to introduce dynamic crosslinks capable of light-initiated addition transfer fragmentation chemistry. Using a custom-built optical cantilever, contrasting film stress responses are observed between films containing dynamic bonds and analogous …


The Profound Photophysical Effects Of Organic Chromophore Connectivity And Coupling, David J. Walwark Jr Nov 2021

The Profound Photophysical Effects Of Organic Chromophore Connectivity And Coupling, David J. Walwark Jr

Nanoscience and Microsystems ETDs

Through-bond and through-space interactions between chromophores are shown to have wide-ranging effects on photophysical outcomes upon light absorption in organic molecules. In collapsed poly(3-hexylthiophene), through-space coupling creates hybrid chromophores that act as energy sinks for nearby excitons and favorable sites for molecular oxygen to dock. Upon excitation with visible light the highly-coupled chromophores react with the docked oxygen and subsequently do not quench nearby excitons as efficiently. In tetramer arrays of perylene diimide chromophores the central moiety through-bond connectivity is synthesized in two variants which exhibit vastly different single-molecule blinking behavior and theoretically-predicted electronic transition character. In the more-connected tetramer …


Exploring The Geometric And Electronic Properties Of Palladium Doped Silicon Clusters, Madison Winkeler, Ciara N. Richardson Nov 2021

Exploring The Geometric And Electronic Properties Of Palladium Doped Silicon Clusters, Madison Winkeler, Ciara N. Richardson

Scholars Week

Transition metal-doped silicon clusters have unique properties and have been studied as building blocks for nanomaterials and microelectronics. Here, the structure and properties of candidate palladium doped silicon clusters (SinPd2: n=1-17) were determined using global optimization techniques on a high performance computing cluster at the San Diego Supercomputing Center. Then geometric structures were further optimized utilizing the B3LYP method with 6-311+G(d) basis sets for silicon and lanl2dz pseudopotential for palladium, followed by the larger DSDPBEP86 method with 6-311+G(2d) basis sets for silicon and SDD pseudopotential for palladium, as implemented in the Gaussian 16 program package. The energetics for each cluster …


New Methods For The Synthesis, Activation, And Application Of Thioglycosides, Samira Escopy Nov 2021

New Methods For The Synthesis, Activation, And Application Of Thioglycosides, Samira Escopy

Dissertations

From their ubiquitous presence in Nature to their vital roles in biology and medicine, carbohydrates (sugars or glycans) are essential molecules of life, which are made and/or utilized by every living organism. Our cells are coated with sugars that are involved in almost every biological process and defensive mechanism in our body. To mention some of their crucial biological functions, carbohydrates are essential source of energy, they participate in blood coagulation, immune defense, cell growth, cell-cell interaction, and anti-inflammatory processes. Understanding of glycan functions and structure is crucial for the development of vaccines and therapeutics. Producing complex carbohydrates in sufficient …


Single-Molecule Localization Microscopy Of 3d Orientation And Anisotropic Wobble Using A Polarized Vortex Point Spread Function, Tianben Ding, Matthew D. Lew Nov 2021

Single-Molecule Localization Microscopy Of 3d Orientation And Anisotropic Wobble Using A Polarized Vortex Point Spread Function, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Within condensed matter, single fluorophores are sensitive probes of their chemical environments, but it is difficult to use their limited photon budget to image precisely their positions, 3D orientations, and rotational diffusion simultaneously. We demonstrate the polarized vortex point spread function (PSF) for measuring these parameters, including characterizing the anisotropy of a molecule’s wobble, simultaneously from a single image. Even when imaging dim emitters (∼500 photons detected), the polarized vortex PSF can obtain 12 nm localization precision, 4°–8° orientation precision, and 26° wobble precision. We use the vortex PSF to measure the emission anisotropy of fluorescent beads, the wobble dynamics …


Biotinylation As A Tool To Enhance The Uptake Of Small Molecules In Gram-Negative Bacteria, Ankit Pandeya, Ling Yang, Olaniyi Alegun, Chamikara Karunasena, Chad Risko, Zhenyu Li, Yinan Wei Nov 2021

Biotinylation As A Tool To Enhance The Uptake Of Small Molecules In Gram-Negative Bacteria, Ankit Pandeya, Ling Yang, Olaniyi Alegun, Chamikara Karunasena, Chad Risko, Zhenyu Li, Yinan Wei

Chemistry Faculty Publications

Antibiotic resistance is a major public health concern. The shrinking selection of effective antibiotics and lack of new development is making the situation worse. Gram-negative bacteria more specifically pose serious threat because of their double layered cell envelope and effective efflux systems, which is a challenge for drugs to penetrate. One promising approach to breach this barrier is the “Trojan horse strategy”. In this technique, an antibiotic molecule is conjugated with a nutrient molecule that helps the antibiotic to enter the cell through dedicated transporters for the nutrient. Here, we explored the approach using biotin conjugation with a florescent molecule …


Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer Nov 2021

Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer

LSU Doctoral Dissertations

This dissertation contains two separate sections aside from an introduction (Chapter 1): theory and methods (Chapter 2), time dependent density functional theory with Ehrenfest for excited state lifetimes in materials (Chapter 3), and simulated field modulated X-ray absorption in titania (Chapter 4).

Excited state lifetime in insulators and semiconductors can be difficult to compute using quantum chemistry due to their dense excited states. Non-radiative decay in these materials requires the use of non-adiabatic effects to dissipate energy through the means of electron-nuclear coupling such as coherent phonon generation. One method of approaching this challenge in these materials is using Ehrenfest …


The Photophysical Studies Of Transition Metal Polyimines Encapsulated In Metal Organic Frameworks (Mof’S), Jacob M. Mayers Nov 2021

The Photophysical Studies Of Transition Metal Polyimines Encapsulated In Metal Organic Frameworks (Mof’S), Jacob M. Mayers

USF Tampa Graduate Theses and Dissertations

Light harvesting systems provide a platform that converts solar energy into other forms of energy. One of the most common examples of photon capturing and conversion into chemical energy is observed in photosynthetic organisms in both Eurkaroyic and Prokaryotic domains. Nature provides a model for successful light harvesting platforms which includes the compartmentalization of antenna complexes that contain separated donor and acceptor pairs that participate in efficient electron transfer processes. In order to mimic such systems, crystalline porous materials that exhibits regular cavities and pore dimensions provides an excellent starting place. Metal organic frameworks (MOFs) are a class of porous …


Cu-Catalyzed Phenol O-Methylation With Methylboronic Acid, Mairead E. Bartlett, Yingchuan Zhu, Uma Bhagwat Gaffney, Joyce Lee, Miranda Wu, Betemariam Sharew, Angela K. Chavez, David J. Gorin Nov 2021

Cu-Catalyzed Phenol O-Methylation With Methylboronic Acid, Mairead E. Bartlett, Yingchuan Zhu, Uma Bhagwat Gaffney, Joyce Lee, Miranda Wu, Betemariam Sharew, Angela K. Chavez, David J. Gorin

Chemistry: Faculty Publications

A Cu-catalyzed oxidative cross-coupling of phenols with methylboronic acid to form aryl methyl ethers has been developed, expanding the scope of Chan-Evans-Lam alkylation. Electron-deficient phenol derivatives with a broad array of functional groups are methylated in high yields. Increased reaction temperature and catalyst loading enables the methylation of substrates incorporating pyridine and dihydroquinolone motifs. Electron-rich phenol derivatives are poor substrates for the methylation; the characterization of C−H homodimerization products formed from these substrates illuminates a competing mechanistic pathway.


The Temperature-Dependent Conformational Ensemble Of Sars-Cov-2 Main Protease (Mpro), Ali Ebrahim, Blake T. Riley, Desigan Kumaran, Babak Andi, Martin R. Fuchs, Sean Mcsweeney, Daniel A. Keedy Nov 2021

The Temperature-Dependent Conformational Ensemble Of Sars-Cov-2 Main Protease (Mpro), Ali Ebrahim, Blake T. Riley, Desigan Kumaran, Babak Andi, Martin R. Fuchs, Sean Mcsweeney, Daniel A. Keedy

Publications and Research

The COVID-19 pandemic, instigated by the SARS-CoV-2 coronavirus, continues to plague the globe. The SARS-CoV-2 main protease, or Mpro, is a promising target for development of novel antiviral therapeutics. Previous X-ray crystal structures of Mpro were obtained at cryogenic temperature or room temperature only. Here we report a series of high-resolution crystal structures of unliganded Mpro across multiple temperatures from cryogenic to physiological, and another at high humidity. We interrogate these datasets with parsimonious multiconformer models, multi-copy ensemble models, and isomorphous difference density maps. Our analysis reveals a temperature-dependent conformational landscape for Mpro, including …


Polyglyoxylamides With A Ph-Mediated Solubility And Depolymerization Switch, Quinton E. A. Sirianni, Xiaoli Liang, Georgina K. Such, Elizabeth Gillies Nov 2021

Polyglyoxylamides With A Ph-Mediated Solubility And Depolymerization Switch, Quinton E. A. Sirianni, Xiaoli Liang, Georgina K. Such, Elizabeth Gillies

Chemistry Publications

Self-immolative polymers (SIPs) are characterized by their ability to depolymerize in response to the cleavage of a single end-cap or backbone moiety, making them attractive for numerous applications including sensors, transient plastics, and delivery vehicles. For many applications, it would be desirable to have an SIP capable of depolymerizing selectively under mildly acidic aqueous conditions. However, the poor solubility of most SIPs in water, accompanied by the competing effects of end-cap cleavage and depolymerization mechanisms, has made this a challenge. Here, we describe the development of polyglyoxylamides (PGAms) with pendent amino groups to achieve solubility switching at mildly acidic pH, …


Issue Of False Amphetamine Field Test Positives Caused By Sugar: Use Of Baeyer Test As A Secondary Test Solution, Reed A. Knutson, Jennah Duncan, Kara Peightal, Samuel Thomas Nov 2021

Issue Of False Amphetamine Field Test Positives Caused By Sugar: Use Of Baeyer Test As A Secondary Test Solution, Reed A. Knutson, Jennah Duncan, Kara Peightal, Samuel Thomas

Department of Chemistry: Dissertations, Theses, and Student Research

The Marquis reagent is a well-established and widely used chemical presumptive test for 3,4-Methylenedioxymethamphetamine (MDMA) and methamphetamine. It is composed of concentrated sulfuric acid and 40% formaldehyde, which act upon alkaloids causing them to complex into larger molecules. This complexation causes a color change that can be visually interpreted as a positive or negative result. Almost any sugar molecule can be complexed in this way as well, due to their many OH groups. Experimentally it was found that the sugar molecules did complex with one another when the Marquis test was administered. The color produced by this reaction was brownish-red. …