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2021

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Articles 601 - 630 of 1742

Full-Text Articles in Chemistry

Recovery Of High Specific Activity Molybdenum-99 From Accelerator-Induced Fission On Low-Enriched Uranium For Technetium-99m Generators, M. Alex Brown, Nathan Johnson, Artem V. Gelis, Milan Stika, Anna G. Servis, Alex Bakken, Christine Krizmanich, Kristin Shannon, Peter Kozak, Amanda Barnhart, Chad Denbrock, Nicolas Luciani, Terry Grimm, Peter Tkac Jun 2021

Recovery Of High Specific Activity Molybdenum-99 From Accelerator-Induced Fission On Low-Enriched Uranium For Technetium-99m Generators, M. Alex Brown, Nathan Johnson, Artem V. Gelis, Milan Stika, Anna G. Servis, Alex Bakken, Christine Krizmanich, Kristin Shannon, Peter Kozak, Amanda Barnhart, Chad Denbrock, Nicolas Luciani, Terry Grimm, Peter Tkac

Chemistry and Biochemistry Faculty Research

A new process was developed to recover high specific activity (no carrier added) 99Mo from electron-accelerator irradiated U3O8 or uranyl sulfate targets. The process leverages a novel solvent extraction scheme to recover Mo using di(2-ethylhexyl) phosphoric acid following uranium and transuranics removal with tri-n-butyl phosphate. An anion-exchange concentration column step provides a final purification, generating pure 99Mo intended for making 99Mo/99mTc generators. The process was demonstrated with irradiated uranium targets resulting in more than 95% 99Mo recovery and without presence of fission products or actinides in the product.

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Multiple Wetting−Dewetting States Of A Water Droplet On Dual- Scale Hierarchical Structured Surfaces, Yurui Gao, Yuan Liu, Jian Jiang, Chongqin Zhu, Craig Zuhlke, Dennis Alexander, Joseph S. Francisco, Xiao Cheng Zeng Jun 2021

Multiple Wetting−Dewetting States Of A Water Droplet On Dual- Scale Hierarchical Structured Surfaces, Yurui Gao, Yuan Liu, Jian Jiang, Chongqin Zhu, Craig Zuhlke, Dennis Alexander, Joseph S. Francisco, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Surfaces with microscale roughness can entail dualscale hierarchical structures such as the recently reported nano/ microstructured surfaces produced in the laboratory (Wang et al. Nature 2020, 582, 55−57). However, how the dual-scale hierarchical structured surface affects the apparent wetting/ dewetting states of a water droplet, and the transitions between the states are still largely unexplored. Here, we report a systematic large-scale molecular dynamics (MD) simulation study on the wetting/dewetting states of water droplets on various dual-scale nano/near-submicrometer structured surfaces. To this end, we devise slab-water/slab-substrate model systems with a variety of dual-scale surface structures and with different degrees of intrinsic …

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A Bacterial Inflammation Sensor Regulates C-Di-Gmp Signaling, Adhesion, And Biofilm Formation, Arden Perkins, Dan A. Tudorica, Raphael D. Teixeira, Tilman Schirmer, Lindsay Zumwalt, O. Maduka Ogba, C. Keith Cassidy, Phillip J. Stansfeld, Karen Guillemin Jun 2021

A Bacterial Inflammation Sensor Regulates C-Di-Gmp Signaling, Adhesion, And Biofilm Formation, Arden Perkins, Dan A. Tudorica, Raphael D. Teixeira, Tilman Schirmer, Lindsay Zumwalt, O. Maduka Ogba, C. Keith Cassidy, Phillip J. Stansfeld, Karen Guillemin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacteria that colonize animals must overcome, or coexist, with the reactive oxygen species products of inflammation, a front-line defense of innate immunity. Among these is the neutrophilic oxidant bleach, hypochlorous acid (HOCl), a potent antimicrobial that plays a primary role in killing bacteria through nonspecific oxidation of proteins, lipids, and DNA. Here, we report that in response to increasing HOCl levels, Escherichia coli regulates biofilm production via activation of the diguanylate cyclase DgcZ. We identify the mechanism of DgcZ sensing of HOCl to be direct oxidation of its regulatory chemoreceptor zinc-binding (CZB) domain. Dissection of CZB signal transduction reveals that …

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Special Issue Editorial: Current Advances In Liquid Crystals, Pradip K. Bhowmik Jun 2021

Special Issue Editorial: Current Advances In Liquid Crystals, Pradip K. Bhowmik

Chemistry and Biochemistry Faculty Research

No abstract provided.

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A Fret Flow Cytometry-Based Screening Assay For Multiplex Analysis Of Metabolites In T. Brucei, Ronald A. Zegarra Jun 2021

A Fret Flow Cytometry-Based Screening Assay For Multiplex Analysis Of Metabolites In T. Brucei, Ronald A. Zegarra

Undergraduate Honors Theses

Kinetoplastid parasites are a significant public health issue in some tropical and subtropical regions of the world. Kinetoplastid parasites all require glycolysis for survival, with host glucose key for ATP production. One such parasite, Trypanosoma brucei, exclusively metabolizes glucose in its bloodstream form. Trypanosomal glycolysis is unique because it displays unconventional structural features. Hence, glucose metabolism has been studied extensively in T. brucei and is a therapeutic target in kinetoplastid parasites.The lack of in vivo analytical techniques for measuring vital glycolytic metabolites in situ has restricted the ability of researchers to test, with high sensitivity and specificity, the essential roles …

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Characterization Of Extracellular Vesicles Derived From Mesenchymal Stromal Cells By Surface-Enhanced Raman Spectroscopy., Nina M. Culum, Tyler T. Cooper, Gillian I. Bell, David A. Hess, François Lagugné-Labarthet Jun 2021

Characterization Of Extracellular Vesicles Derived From Mesenchymal Stromal Cells By Surface-Enhanced Raman Spectroscopy., Nina M. Culum, Tyler T. Cooper, Gillian I. Bell, David A. Hess, François Lagugné-Labarthet

Chemistry Publications

Extracellular vesicles (EVs) are secreted by all cells into bodily fluids and play an important role in intercellular communication through the transfer of proteins and RNA. There is evidence that EVs specifically released from mesenchymal stromal cells (MSCs) are potent cell-free regenerative agents. However, for MSC EVs to be used in therapeutic practices, there must be a standardized and reproducible method for their characterization. The detection and characterization of EVs are a challenge due to their nanoscale size as well as their molecular heterogeneity. To address this challenge, we have fabricated gold nanohole arrays of varying sizes and shapes by …

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Data From: A Sandwich-Type Cluster Containing Ge@Pd3 Planar Fragment Flanked By Aromatic Nonagermanide Caps, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: A Sandwich-Type Cluster Containing Ge@Pd3 Planar Fragment Flanked By Aromatic Nonagermanide Caps, Alexander I. Boldyrev, Nikolay Tkachenko

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Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)]4{(Ge9)2[η6-Ge(PdPPh3)3]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd3. The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp2-Ge@(PdPPh3)3 trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge σ-bonds attaching Pd atoms to the core Ge …

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Data From: Chemical Bonding Analysis Of Excited States Using The Adaptive Natural Density Partitioning Method, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Chemical Bonding Analysis Of Excited States Using The Adaptive Natural Density Partitioning Method, Alexander I. Boldyrev, Nikolay Tkachenko

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A novel approach to chemical bond analysis for excited states has been developed. Using an extended adaptive natural density partitioning method (AdNDP) as implemented in AdNDP 2.0 code, we obtained chemically intuitive bonding patterns for the excited states of H2O, B5+, and C2H4+ molecules. The deformation pathway in the excited states could be easily predicted based on the analysis of the chemical bond pattern. We expect that this new method of chemical bonding analysis would be very helpful for photochemistry, photoelectron spectroscopy, electron spectroscopy and other chemical applications that involved excited states.

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Data From: Stability, Electronic, And Optical Properties Of Two-Dimensional Phosphoborane, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Stability, Electronic, And Optical Properties Of Two-Dimensional Phosphoborane, Alexander I. Boldyrev, Nikolay Tkachenko

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The structure and properties of two-dimensional phosphoborane sheets were computationally investigated using Density Functional Theory calculations. The calculated phonon spectrum and band structure point to dynamic stability and allowed characterization of the predicted two-dimensional material as a direct-gap semiconductor with a band gap of ~1.5 eV. The calculation of the optical properties showed that the two-dimensional material has a relatively small absorptivity coefficient. The parameters of the mechanical properties characterize the two-dimensional phosphoborane as a relatively soft material, similar to the monolayer of MoS2. Assessment of thermal stability by the method of molecular dynamics indicates sufficient stability of the predicted …

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Data From: Novel Strongly Correlated Europium Superhydrides, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Novel Strongly Correlated Europium Superhydrides, Alexander I. Boldyrev, Nikolay Tkachenko

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We conducted a joint experimental–theoretical investigation of the high-pressure chemistry of europium polyhydrides at pressures of 86–130 GPa. We discovered several novel magnetic Eu superhydrides stabilized by anharmonic effects: cubic EuH9, hexagonal EuH9, and an unexpected cubic (Pm3n) clathrate phase, Eu8H46. Monte Carlo simulations indicate that cubic EuH9 has antiferromagnetic ordering with TN of up to 24 K, whereas hexagonal EuH9 and Pm3n-Eu8H46 possess ferromagnetic ordering with TC = 137 and 336 K, respectively. The electron–phonon interaction is weak in all studied europium hydrides, and their magnetic ordering excludes s-wave superconductivity, except, perhaps, for distorted pseudohexagonal EuH9. The equations of …

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Data From: Computational Prediction Of The Low-Temperature Ferromagnetic Semiconducting 2d Sin Monolayer, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Computational Prediction Of The Low-Temperature Ferromagnetic Semiconducting 2d Sin Monolayer, Alexander I. Boldyrev, Nikolay Tkachenko

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Since the discovery of graphene, 2D materials have captured the minds of scientists because of their attractive and unique electronic properties. In particular, magnetic 2D materials have become a subject of extensive discussions today. Using density functional theory calculations, it is shown that 2D SiN sheet (built out of nonmetallic main group atoms) is a ferromagnetic semiconducting material with a magnetic moment 1 μB per unit cell and an indirect bandgap of 1.55 eV. Calculated phonon spectrum and conducted ab initio molecular dynamics simulation reveal thermal and dynamical stability of the designed material. It is shown that the ferromagnetic state …

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Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur Jun 2021

Exploration Of Fluorinated Α,Β-Dehydroamino Acids And Their Structure, Austin Lesueur

Undergraduate Honors Theses

This thesis explores the synthesis of fluorinated α,β-dehydroamino acids, specifically a fluorinated dehydrovaline derivative. Previous work has been done on the equivalent dehydrovaline derivative without fluorine present and this work builds toward the fluorinated version with the goal of comparing the two structurally. The synthesis presented here pulls from previous synthetic strategies employed for dehydrovaline while also exploring the synthetic impact of the electronegative fluorine atoms.

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Data For: Record Low Ionization Potentials Of Alkali Metal Complexes With Crown Ethers And Cryptands, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data For: Record Low Ionization Potentials Of Alkali Metal Complexes With Crown Ethers And Cryptands, Alexander I. Boldyrev, Nikolay Tkachenko

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Electronic properties of series of alkali metals complexes with crown ethers and cryptands were studied via DFT hybrid functionals. For [M([2.2.2]crypt)] (M=Li, Na, K) extremely low (1.70–1.52 eV) adiabatic ionization potentials were found. Such low values of ionization energies are significantly lower than those of alkali metal atoms. Thus, the investigated complexes can be defined as superalkalis. As a result, our investigation opens up new directions in the designing of chemical species with record low ionization potentials and extends the explanation of the ability of the cryptates and alkali crown ether complexes to stabilize multiple charged Zintl ions.

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Dataset For: Multiple Local Σ-Aromaticity Of Nonagermanide Clusters, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Dataset For: Multiple Local Σ-Aromaticity Of Nonagermanide Clusters, Alexander I. Boldyrev, Nikolay Tkachenko

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Nonagermanide clusters are widely used in inorganic synthesis and are actively studied by experimentalists and theoreticians. However, chemical bonding of such versatile species is still not completely understood. In our work we deciphered a bonding pattern for various experimentally obtained nonagermanide species. We localized the electron density via the AdNDP algorithm for the model structures ([Ge9]4−, [Ge9{P(NH2)2}3]−, Cu[Ge9{P(NH2)2}3] and Cu(NHC)[Ge9{P(NH2)2}3]) and obtained a simple and chemically intuitive bonding pattern which can explain the variety of active sites and the existence of both D3h and C4v geometries for such clusters. Moreover, the [Ge9]4− core is found to be a unique example …

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Data From: Dibridged, Monobridged, Vinylidene-Like, And Linear Structures For The Alkaline Earth Dihydrides Be2h2, Mg2h2, Ca2h2, Sr2h2, And Ba2h2. Proposals For Observations, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Dibridged, Monobridged, Vinylidene-Like, And Linear Structures For The Alkaline Earth Dihydrides Be2h2, Mg2h2, Ca2h2, Sr2h2, And Ba2h2. Proposals For Observations, Alexander I. Boldyrev, Nikolay Tkachenko

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This research reports a search for peculiar monobridged structures of the E2H2 molecules (E = Be, Mg, Ca, Sr, Ba). For Be2H2 and Mg2H2, the monobridged geometry is not an equilibrium but rather a transition state between the vinylidene-like structure and the global minimum HE–EH linear geometry. However, for Ca2H2, Sr2H2, and Ba2H2, this situation changes significantly; the linear structure is no longer the global minimum but lies higher in energy than two other equilibria, the dibridged and monobridged structures. The planar dibridged structures of both Sr2H2 and Ba2H2 should be observable via IR spectroscopy. Although the remarkable monobridged structures …

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Data From: Structure And Bonding In [Sb@In8sb12]3− And [Sb@In8sb12]5−, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Structure And Bonding In [Sb@In8sb12]3− And [Sb@In8sb12]5−, Alexander I. Boldyrev, Nikolay Tkachenko

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We report the characterization of the compound [K([2.2.2]crypt)]4[In8Sb13], which proves to contain a 1:1 mixture of [Sb@In8Sb12]3− and [Sb@In8Sb12]5−. The tri-anion displays perfect Th symmetry, the first completely inorganic molecule to do so, and contains eight equivalent In3+ centers in a cube. The gas-phase potential energy surface of the penta-anion has eight equivalent minima where the extra pair of electrons is localized on one In+ center, and these minima are linked by low-lying transition states where the electron pair is delocalized over two adjacent centers. The best fit to the electron density is obtained from a model where the structure …

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Data From: Σ-Aromaticity-Induced Stabilization Of Heterometallic Supertetrahedral Clusters [Zn6ge16]4− And [Cd6ge16]4−, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: Σ-Aromaticity-Induced Stabilization Of Heterometallic Supertetrahedral Clusters [Zn6ge16]4− And [Cd6ge16]4−, Alexander I. Boldyrev, Nikolay Tkachenko

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In this work, the largest heterometallic supertetrahedral clusters, [Zn6Ge16]4− and [Cd6Ge16]4−, were directly self-assembled through highly-charged [Ge4]4− units and transition metal cations, in which 3-center–2-electron σ bonding in Ge2Zn or Ge2Cd triangles plays a vital role in the stabilization of the whole structure. The cluster structures have an open framework with a large central cavity of diameter 4.6 Å for Zn and 5.0 Å for Cd, respectively. Time-dependent HRESI-MS spectra show that the larger clusters grow from smaller components with a single [Ge4]4− and ZnMes2 units. Calculations performed at the DFT level indicate a very large HOMO–LUMO energy gap in …

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Data From: All-Metal Σ-Antiaromaticity In Dimeric Cluster Anion {[Cuge9mes]2}4−, Alexander I. Boldyrev, Nikolay Tkachenko Jun 2021

Data From: All-Metal Σ-Antiaromaticity In Dimeric Cluster Anion {[Cuge9mes]2}4−, Alexander I. Boldyrev, Nikolay Tkachenko

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In this work, we report a dimeric cluster anion, {[CuGe9Mes]2}4−, which was isolated as the [K(2,2,2-crypt)]+ salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The title cluster represents the first locally σ-antiaromatic compound in the solid state, as well as the first heteroatomic antiaromatic compound.

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Characterizing The Vibrational Spectra Of Hydrogen Bonded Systems With Molecular Dynamics Simulations And Quantum Chemical Methods, Dalton Boutwell Jun 2021

Characterizing The Vibrational Spectra Of Hydrogen Bonded Systems With Molecular Dynamics Simulations And Quantum Chemical Methods, Dalton Boutwell

Master of Science in Chemical Sciences Theses

We apply and assess the utility of DMD for the purpose of investigating complex spectral features in N2H+···OC, N2D+···OC, C2O4H-, C2O4D- and (HCOOH)2. The proton transfer as a vibrational motion consists of diffuse qualities that can be accounted for with classical and quantum chemical analyses. Classical approaches yield a wealth of information about vibrational spectra at a reduced cost, as in the case of previously investigated N4H+. The isoelectronic N2H+···OC has …

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Exploiting Light Interferences To Generate Micrometer-High Superstructures From Monomeric Azo Materials With Extensive Orientational Mobility, Florent Rodriguez, Joachim Jelken, Nicolas Delpouve, Adèle Laurent, Bertrand Garnier, Jean-Luc Duvail, Francois Lagugne-Labarthet, Eléna Ishow Jun 2021

Exploiting Light Interferences To Generate Micrometer-High Superstructures From Monomeric Azo Materials With Extensive Orientational Mobility, Florent Rodriguez, Joachim Jelken, Nicolas Delpouve, Adèle Laurent, Bertrand Garnier, Jean-Luc Duvail, Francois Lagugne-Labarthet, Eléna Ishow

Chemistry Publications

Photochromic azo materials have stirred considerable interest for their ability to mechanically respond to polarized light through large photo-induced migration and orientation processes. In order to apprehend the microscopic dynamics behind the extensive mass transport occurring under interferential illumination, two azo compounds differing by their propen-sity to form hydrogen bonds are synthesized and processed as nondoped glassy thin films. Interferential irradiation using polarization and intensity patterns reveals fully distinct responses. Regular nanometer-high surface relief gratings transform into micrometer superstructures with an ampli-tude ten times higher than the initial film thickness when using the latter polarization. Systematic comparisons between the azo …

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Mathematical Model For Measuring The Concentration Of Nanoparticles In A Liquid During Sedimentation, Safaa Mohammed Ridha Hussien Hussien, Airat Sakhabutdinov, Vladimir Anfinogentov, Maxim Danilaev, Vladimir Kuklin, Oleg Morozov Jun 2021

Mathematical Model For Measuring The Concentration Of Nanoparticles In A Liquid During Sedimentation, Safaa Mohammed Ridha Hussien Hussien, Airat Sakhabutdinov, Vladimir Anfinogentov, Maxim Danilaev, Vladimir Kuklin, Oleg Morozov

Karbala International Journal of Modern Science

Expanding the application areas of polymer composite materials with dispersed filler requires the development of technologies providing the required mechanical characteristics. One of these methods is based on forming a thin polymer shell on the surfaces of particles. At the same time, it is impossible to take into account the mechanical characteristics of a thin polymer shell due to its ultra-small thickness. The mechanical properties of the polymer shell can be determined only by indirect methods, and prior information can improve the adequacy of the properties determination. The method, which allows reducing the requirements for composite sample preparation, is proposed. …

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Role Of Lepidium Sativum In Treating Diabetes And Managing Bodily Functions’ Disorders In Rats., Gehan El-Emary Jun 2021

Role Of Lepidium Sativum In Treating Diabetes And Managing Bodily Functions’ Disorders In Rats., Gehan El-Emary

Karbala International Journal of Modern Science

: Lepidium sativum seed (LS) is a plant used globally for its medicinal effect in treating diabetes. This study examined the ability of an aqueous extract of LS to treat diabetes and manage disorders of bodily functions. It used 70 male Wistar rats, each weighing between 190 g and 200 g. Diabetes was established in the rats by injecting them with Alloxan Solution at 150 mg/kg of body weight. The rats were considered diabetic if, after 24 hours, their blood glucose levels were higher than 180 mg/dl. Diabetes caused severe alterations in their blood serum glucose (376.608 mg/dl); …

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Editorial Board Jun 2021

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

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Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts Jun 2021

Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts

University Honors Theses

Soft lithography is a well-established route to wafer-scale reproduction of micro- and nanoscale features in a wide variety of materials. Nevertheless, micron length scales have yet to be explored, despite the potential utility of such structures. Here, polymer micropillars of 6-12 μm length, approximately 0.5-1.5 μm wide at 10 μm spacing are reproduced from a polydimethylsiloxane (PDMS) mold made from patterned cellulose acetate (CA). The patterned CA was cast from a rigid fused silica template machined by a pulsed femtosecond laser. Pore topographic features were successfully reproduced in Norland Optical Adhesive (NOA), polycaprolactone (PCL), Nafion, acrylonitrile butadiene styrene (ABS), and …

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Donnan Potential Across The Outer Membrane Of Gram-Negative Bacteria And Its Effect On The Permeability Of Antibiotics, Olaniyi Alegun, Ankit Pandeya, Jian Cui, Isoiza Ojo, Yinan Wei Jun 2021

Donnan Potential Across The Outer Membrane Of Gram-Negative Bacteria And Its Effect On The Permeability Of Antibiotics, Olaniyi Alegun, Ankit Pandeya, Jian Cui, Isoiza Ojo, Yinan Wei

Chemistry Faculty Publications

The cell envelope structure of Gram-negative bacteria is unique, composed of two lipid bilayer membranes and an aqueous periplasmic space sandwiched in between. The outer membrane constitutes an extra barrier to limit the exchange of molecules between the cells and the exterior environment. Donnan potential is a membrane potential across the outer membrane, resulted from the selective permeability of the membrane, which plays a pivotal role in the permeability of many antibiotics. In this review, we discussed factors that affect the intensity of the Donnan potential, including the osmotic strength and pH of the external media, the osmoregulated periplasmic glucans …

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Dataset For Characterization Of ‘Cool’ And ‘Warm’ White Leds, Edward Navarre Jun 2021

Dataset For Characterization Of ‘Cool’ And ‘Warm’ White Leds, Edward Navarre

SIUE Faculty Research, Scholarship, and Creative Activity

The emission properties of “cool” and “warm” white LEDs were studied. The suitability of pulse-width modulation as a method to control LED brightness was examined. Both types of LED demonstrated emission standard deviation minima at a PWM frequency greater than 2000 Hz. The functional wavelength ranges of the LEDs were approximated using the linearity of brightness as a function of pulse-width modulation duty-cycle and the root mean squared deviation from mean for absorbance measurements. Both LED types demonstrated good stability in absorbance measurements over long operation times. The “warm” LED demonstrated a broader range of wavelengths useful for spectrophotometry. This …

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Efficacy Of Ryr2 Inhibitor El20 In Induced Pluripotent Stem Cell-Derived Cardiomyocytes From A Patient With Catecholaminergic Polymorphic Ventricular Tachycardia., Tarah A. Word, Ann P. Quick, Christina Y. Miyake, Mayra K. Shak, Xiaolu Pan, Jean J. Kim, Hugh D. Allen, Martha Sibrian-Vazquez, Robert M. Strongin, Andrew P. Landstrom, Xander H T Wehrens Jun 2021

Efficacy Of Ryr2 Inhibitor El20 In Induced Pluripotent Stem Cell-Derived Cardiomyocytes From A Patient With Catecholaminergic Polymorphic Ventricular Tachycardia., Tarah A. Word, Ann P. Quick, Christina Y. Miyake, Mayra K. Shak, Xiaolu Pan, Jean J. Kim, Hugh D. Allen, Martha Sibrian-Vazquez, Robert M. Strongin, Andrew P. Landstrom, Xander H T Wehrens

Chemistry Faculty Publications and Presentations

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac arrhythmia syndrome that often leads to sudden cardiac death. The most common form of CPVT is caused by autosomal-dominant variants in the cardiac ryanodine receptor type-2 (RYR2) gene. Mutations in RYR2 promote calcium (Ca ) leak from the sarcoplasmic reticulum (SR), triggering lethal arrhythmias. Recently, it was demonstrated that tetracaine derivative EL20 specifically inhibits mutant RyR2, normalizes Ca handling and suppresses arrhythmias in a CPVT mouse model. The objective of this study was to determine whether EL20 normalizes SR Ca handling and arrhythmic events in induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) …

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Total Synthesis And Antimalarial Activity Of 2-(-Hydroxybenzyl)-Prodigiosins, Isoheptylprodigiosin, And Geometric Isomers Of Tambjamine Myp1 Isolated From Marine Bacteria., Papireddy Kancharla, Yuexin Li, Monish Yeluguri, Rozalia A. Dodean, Kevin A. Reynolds, Jane X. Kelly Jun 2021

Total Synthesis And Antimalarial Activity Of 2-(-Hydroxybenzyl)-Prodigiosins, Isoheptylprodigiosin, And Geometric Isomers Of Tambjamine Myp1 Isolated From Marine Bacteria., Papireddy Kancharla, Yuexin Li, Monish Yeluguri, Rozalia A. Dodean, Kevin A. Reynolds, Jane X. Kelly

Chemistry Faculty Publications and Presentations

Highly efficient and straightforward synthetic routes toward the first total synthesis of 2-(-hydroxybenzyl)-prodigiosins (-), isoheptylprodigiosin (), and geometric isomers of tambjamine MYP1 ((/)-) have been developed. The crucial steps involved in these synthetic routes are the construction of methoxy-bipyrrole-carboxaldehydes (MBCs) and a 20-membered macrocyclic core and a regioselective demethylation of MBC analogues. These new synthetic routes enabled us to generate several natural prodiginines - in larger quantity. All of the synthesized natural products exhibited potent asexual blood-stage antiplasmodial activity at low nanomolar concentrations against a panel of parasites, with a great therapeutic index. Notably, prodiginines and - provided curative in …

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Β -Technetium: An Allotrope With A Nonstandard Volume-Pressure Relationship, Emily Siska, Dean Smith, Christian Childs, Daniel Koury, Paul M. Forster, Keith V. Lawler, Ashkan Salamat Jun 2021

Β -Technetium: An Allotrope With A Nonstandard Volume-Pressure Relationship, Emily Siska, Dean Smith, Christian Childs, Daniel Koury, Paul M. Forster, Keith V. Lawler, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

We report the synthesis and structure of the second allotrope of technetium, β-Tc. Transformative pathways are accessed at extreme conditions using the laser-heated diamond anvil cell and confirmed with in situ synchrotron x-ray diffraction and Raman spectroscopy. β-Tc is fully recoverable to ambient conditions, although counter to our DFT calculations predicting a face-centered-cubic lattice, we observe a tetragonal structure (I4/mmm) that exhibits further tetragonal distortion with pressure. β-Tc has an expanded volume relative to the hcp ground state phase, that when doped with nitrogen has an unexpected volume lowering. Such anomalous behavior is possibly indicative of a rare electronic phase …

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Fullerene And Tungsten Oxide Nanostructures-Based Electrocatalysts For All-Vanadium Redox Flow Batteries, Farah Ahmed El Diwany Jun 2021

Fullerene And Tungsten Oxide Nanostructures-Based Electrocatalysts For All-Vanadium Redox Flow Batteries, Farah Ahmed El Diwany

Theses and Dissertations

The vanadium redox flow battery (VRFB) is one of the most promising long-term energy storage solutions mainly due to its long service life and the independence of its energy capacity on power rating and vice versa. However, its relatively high capital cost limits its widespread deployment. Economic analysis reveals that a high-power density VRFB with decreased cell stack size can dramatically reduce the cost. The energy efficiency of a VRFB primarily depends on the kinetics of vanadium redox reactions that take place in the stack. Therefore, studying the effect of surface chemistry of electrodes on the kinetics of each …

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