Chemistry Commons^™

Experimental Data On Water Soluble Polymers Thermal And Hydrolytic Stability, Reactivity Ratios Of Monomers And Frr Calculation For Thermally Stable Preformed Particle Gels Therefrom, Buddhabhushan Salunkhe, Thomas P. Schuman, Ali Al Brahim, Baojun Bai

Chemistry Faculty Research & Creative Works

Experimental data on water soluble polymer thermal and hydrolytic stability in acidic, neutral and basic pH conditions in aqueous solution is presented. Thermal and hydrolytic stability of polymer aqueous solutions were monitored in variable pH medium by aging at 130 °C temperature for different aging time. Polymer viscosity measurements were performed periodically for 3 months. Furthermore, this data can serve as a basis of monomer selection for thermally stable hydrogels for applications like oil recovery, hydrogel coatings for steam sterilized medical devices and other applications. Reactivity ratios were determined for monomers associated to the most stable polymers using ¹H …

Preparation And Pharmacokinetic Characterization Of An Anti-Virulence Compound Nanosuspensions, Nan Wang, Feng Qi, Xiaolong He, Honglan Shi, David W. Anderson, Hao Li, Hongmin Sun

Chemistry Faculty Research & Creative Works

Antibiotic resistance has become a worldwide public health threat due to the rapid evolu-tion and spread of antibiotic-resistant bacteria. CCG-211790 is a novel anti-virulence compound that does not kill bacteria but could ameliorate human diseases by inhibiting expression of virulence factors, thereby applying less selection pressure for antibiotic resistance. However, its potential clinical use is restricted because of its poor aqueous solubility, resulting in formulation challenges. Nanosuspension technology is an effective way to circumvent this problem. Nanosuspensions of CCG-211790 with two different particle sizes, NanoA (315 ± 6 nm) and NanoB (915 ± 24 nm), were prepared using an antisolvent …

Calibration Of Gas Flow Meters Using Choked Flow And An Evacuated Vessel, Max B. Trueblood, Otmar Schmid, Nicholas Altese, Christian J. Hurst, Wenyan Liu, Teresa Gelles, Steven C. Achterberg, Philip D. Whitefield, Donald E. Hagen

Chemistry Faculty Research & Creative Works

The measurement of gas flow rates is of great importance in a wide range of modern technologies. This paper introduces a simple, yet accurate technique for in-house calibration of gas FMs (mass and volumetric) even under harsh environmental conditions such as encountered during field measurement campaigns. The method requires only readily available, low cost components: a vessel of known volume, an air pump, a pressure sensor and a metal plate orifice or a needle valve to act as a CO. The unique property of choked flow in the CO is used here for flow calibration. In the method presented here …

Genotype, Age, Genetic Background, And Sex Influence Epha2-Related Cataract Development In Mice, Alpana Dave, Jamie E. Craig, Mohammad Alamein, Karina Skrzypiec, Justin Beltz, Annalise Pfaff, Kathryn P. Burdon, Nuran Ercal, Robb U. De Iongh, Shiwani Sharma

Chemistry Faculty Research & Creative Works

PURPOSE. Age-related cataract is the leading cause of blindness worldwide. Variants in the EPHA2 gene increase the disease risk, and its knockout in mice causes cataract. We investigated whether age, sex, and genetic background, risk factors for age-related cataract, and Epha2 genotype influence Epha2-related cataract development in mice.

METHODS. Cataract development was monitored in Epha2⁺/⁺, Epha2^+/-, and Epha2^-/- mice (Epha2^{Gt(KST085)Byg}) on C57BL/6J and FVB:C57BL/6J (50:50) backgrounds. Cellular architecture of lenses, endoplasmic reticulum (ER) stress, and redox state were determined using histological, molecular, and analytical techniques.

RESULTS. Epha2^-/- and Epha2^{+/- …}

Continuous Measurement Of Reactive Oxygen Species Inside And Outside Of A Residential House During Summer, Azin Eftekhari, Claire F. Fortenberry, Brent J. Williams, Michael J. Walker, Audrey Dang, Annalise Pfaff, Nuran Ercal, Glenn C. Morrison

Chemistry Faculty Research & Creative Works

Reactive oxygen species (ROS) are an important contributor to adverse health effects associated with ambient air pollution. Despite infiltration of ROS from outdoors, and possible indoor sources (eg, combustion), there are limited data available on indoor ROS. In this study, part of the second phase of Air Composition and Reactivity from Outdoor aNd Indoor Mixing campaign (ACRONIM-2), we constructed and deployed an online, continuous, system to measure extracellular gas- and particle-phase ROS during summer in an unoccupied residence in St. Louis, MO, USA. Over a period of one week, we observed that the non-denuded outdoor ROS (representing particle-phase ROS and …

Copper Selenide As Multifunctional Non-Enzymatic Glucose And Dopamine Sensor, Harish Singh, Jillian Bernabe, Justin Chern, Manashi Nath

Chemistry Faculty Research & Creative Works

Cu₂Se, synthesized through one-pot hydrothermal synthesis, was identified as highly efficient bifunctional sensor for co-detection of glucose and dopamine with high selectivity. As-synthesized copper selenide could electro-oxidize glucose and dopamine at different applied potentials. Glucose oxidation was observed at 0.35 V while dopamine oxidized at 0.2 V. This copper selenide-based non-enzymatic sensor showed high sensitivity for both glucose (15.341 mA mM^-1 cm^-2) and dopamine (12.43 μA μM^-1 cm^-2) with low limit of detection (0.26 μM and 84 nM). Such high sensitivity and low LOD makes this sensor attractive for possible detection of …

Temperature-Dependent Rotationally Inelastic Collisions Of Ohˉ And He, Eric S. Endres, Steve Ndengué, Olga Lakhmanskaya, Seunghyun Lee, Francesco A. Gianturco, Richard Dawes, Roland Wester

Chemistry Faculty Research & Creative Works

We have studied the fundamental rotational relaxation and excitation collision of OHˉJ = 0 ↔ 1 with helium at different collision energies. Using state-selected photodetachment in a cryogenic ion trap, the collisional excitation of the first excited rotational state of OHˉ has been investigated and absolute inelastic collision rate coefficients have been extracted for collision temperatures between 20 and 35 K. The rates are compared with accurate quantum scattering calculations for three different potential-energy surfaces. Good agreement is found within the experimental accuracy, but the experimental trend of increasing collision rates with temperature is only in part reflected in the …

Metal Foils With Ordered Crystal Structure And Method For Producing Metal Foils, Jay A. Switzer

Chemistry Faculty Research & Creative Works

A method for producing a metal foil comprising depositing metal onto an oxidizable substrate to form a metal film on the substrate; oxidizing the substrate at an interface between the metal film and the substrate; and removing the metal film from the substrate to yield a metal foil. A method for forming a thin metal film comprising pre-polarizing a single-crystal Si substrate by application of a potential which is negative of a potential at which Si oxidizes, which pre-polarization occurs in the presence of metal ions to form metal growth nucleation sites on the substrate, followed by application of a …

Achieving Superlubricity With 2d Transition Metal Carbides (Mxenes) And Mxene/Graphene Coatings, S. Huang, K. C. Mutyala, A. V. Sumant, Vadym Mochalin

Chemistry Faculty Research & Creative Works

Two-dimensional (2D) materials have demonstrated unique friction and antiwear properties unmatched by their bulk (3D) counterparts. A relatively new, large and quickly growing family of two-dimensional early transition metal carbides and nitrides (MXenes) present a great potential in different applications. There is a growing interest in understanding the mechanical and tribological properties of MXenes, however, no report of MXene superlubricity in a solid lubrication process at the macroscale has been presented. Here we investigate the tribological properties of two-dimensional titanium carbide (Ti₃C₂) MXene deposited on SiO₂-coated silicon (Si) substrates subjected to wear by sliding …

Disaggregation Of Nanodiamond Particles, Vadym Mochalin, Atsushi Kume, Yoshihiro Inamoto, Masumi Hashimoto

Chemistry Faculty Research & Creative Works

Methods for disaggregating nanodiamond clusters, for example, by using sonication to break apart nanodiamond aggregates in an aqueous slurry having an alkaline pH. Compositions, such as aqueous nanodiamond dispersions and dry particulate compositions can be produced using these methods.

A Molecular Tetrahedral Cobalt-Seleno-Based Complex As An Efficient Electrocatalyst For Water Splitting, Ibrahim Munkaila Abdullahi, Jahangir Masud, Polydoros Chrisovalantis Ioannou, Eleftherios Ferentinos, Panayotis Kyritsis, Manashi Nath

Chemistry Faculty Research & Creative Works

The cobalt-seleno-based coordination complex, [Co{(SePⁱPr₂)₂N}₂], is reported with respect to its catalytic activity in oxygen evolution and hydrogen evolution reactions (OER and HER, respectively) in alkaline solutions. An overpotential of 320 and 630 mV was required to achieve 10 mA cm^-2 for OER and HER, respectively. The overpotential for OER of this CoSe₄-containing complex is one of the lowest that has been observed until now for molecular cobalt(II) systems, under the reported conditions. In addition, this cobalt-seleno-based complex exhibits a high mass activity (14.15 A g^-1) and …

Interplay Between Oxo And Fluoro In Vanadium Oxyfluorides For Centrosymmetric And Non-Centrosymmetric Structure Formation, Prashanth Sandineni, Amitava Choudhury, Hooman Yaghoobnejad Asl, Weiguo Zhang, P. Shiv Halasyamani, Kartik Ghosh

Chemistry Faculty Research & Creative Works

Herein, we report the syntheses of two lithium-vanadium oxide-fluoride compounds crystallized from the same reaction mixture through a time variation experiment. A low temperature hydrothermal route employing a viscous paste of V₂O₅, oxalic acid, LiF, and HF allowed the crystallization of one metastable phase initially, Li₂VO_0.55 (H₂O)_0.45F₅·2H₂O (I), which on prolonged heating transforms to a chemically similar yet structurally different phase, Li₃VOF₅ (II). Compound I crystallizes in centrosymmetric space group, I2/a with a = 6.052(3), b = 7.928(4), …

Physicochemical Properties And Formulation Development Of A Novel Compound Inhibiting Staphylococcus Aureus Biofilm Formation, Nan Wang, Feng Qi, Haqing Yu, Bryan D. Yestrepsky, Scott D. Larsen, Honglan Shi, Juan Ji, David W. Anderson, Hao Li, Hongmin Sun

Chemistry Faculty Research & Creative Works

The emergence of antibiotic resistance over the past several decades has given urgency to new antibacterial strategies that apply less selective pressure. A new class of anti-virulence compounds were developed that are active against methicillin-resistant Staphylococcus aureus (MRSA), by inhibiting bacterial virulence without hindering their growth to reduce the selective pressure for resistance development. One of the compounds CCG-211790 has demonstrated potent anti-biofilm activity against MRSA. This new class of anti-virulence compounds inhibited the gene expression of virulence factors involved in biofilm formation and disrupted the biofilm structures. In this study, the physicochemical properties of CCG- 211790, including morphology, solubility …

Collisional Excitation Of Interstellar Pn By H₂: New Interaction Potential And Scattering Calculations, Benjamin Desrousseaux, Ernesto Quintas-Sánchez, Richard Dawes, Sarantos Marinakis, François Lique

Chemistry Faculty Research & Creative Works

Rotational excitation of interstellar PN molecules induced by collisions with H₂ is investigated. We present the first ab initio four-dimensional potential energy surface (PES) for the PN-H₂ van der Waals system. The PES was obtained using an explicitly correlated coupled cluster approach with single, double, and perturbative triple excitations [CCSD(T)-F12b]. The method of interpolating moving least squares was used to construct an analytical PES from these data. The equilibrium structure of the complex was found to be linear, with H₂ aligned at the N end of the PN molecule, at an intermolecular separation of 4.2 Å. The …

A Deep Learning Model To Predict Traumatic Brain Injury Severity And Outcome From Mr Images, Dacosta Yeboah, Hung Nguyen, Daniel B. Hier, Gayla R. Olbricht, Tayo Obafemi-Ajayi

Chemistry Faculty Research & Creative Works

For Many Neurological Disorders, Including Traumatic Brain Injury (TBI), Neuroimaging Information Plays a Crucial Role Determining Diagnosis and Prognosis. TBI is a Heterogeneous Disorder that Can Result in Lasting Physical, Emotional and Cognitive Impairments. Magnetic Resonance Imaging (MRI) is a Non-Invasive Technique that Uses Radio Waves to Reveal Fine Details of Brain Anatomy and Pathology. Although MRIs Are Interpreted by Radiologists, Advances Are Being Made in the Use of Deep Learning for MRI Interpretation. This Work Evaluates a Deep Learning Model based on a Residual Learning Convolutional Neural Network that Predicts TBI Severity from MR Images. the Model Achieved a …

Schizophrenia Classification Using Resting State Eeg Functional Connectivity: Source Level Outperforms Sensor Level, Sima Azizi, Daniel B. Hier, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Disrupted Functional and Structural Connectivity Measures Have Been Used to Distinguish Schizophrenia Patients from Healthy Controls. Classification Methods based on Functional Connectivity Derived from EEG Signals Are Limited by the Volume Conduction Problem. Recorded Time Series at Scalp Electrodes Capture a Mixture of Common Sources Signals, Resulting in Spurious Connections. We Have Transformed Sensor Level Resting State EEG Times Series to Source Level EEG Signals Utilizing a Source Reconstruction Method. Functional Connectivity Networks Were Calculated by Computing Phase Lag Values between Brain Regions at Both the Sensor and Source Level. Brain Complex Network Analysis Was Used to Extract Features and …

Subsumption Reduces Dataset Dimensionality Without Decreasing Performance Of A Machine Learning Classifier, Donald C. Wunsch, Daniel B. Hier

Chemistry Faculty Research & Creative Works

When Features in a High Dimension Dataset Are Organized Hierarchically, There is an Inherent Opportunity to Reduce Dimensionality. Since More Specific Concepts Are Subsumed by More General Concepts, Subsumption Can Be Applied Successively to Reduce Dimensionality. We Tested Whether Sub-Sumption Could Reduce the Dimensionality of a Disease Dataset Without Impairing Classification Accuracy. We Started with a Dataset that Had 168 Neurological Patients, 14 Diagnoses, and 293 Unique Features. We Applied Subsumption Repeatedly to Create Eight Successively Smaller Datasets, Ranging from 293 Dimensions in the Largest Dataset to 11 Dimensions in the Smallest Dataset. We Tested a MLP Classifier on All …

Preparation Of Green Biosorbent Using Rice Hull To Preconcentrate, Remove And Recover Heavy Metal And Other Metal Elements From Water, Yongbo Dan, Lei Xu, Zhimin Qiang, Huiyu Dong, Honglan Shi

Chemistry Faculty Research & Creative Works

Sodium hydroxide treated rice hulls were investigated to preconcentrate, remove, and recover metal ions including Be²⁺, Al³⁺, Cr³⁺, CO²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Sr²⁺, Ag⁺, Cd²⁺, Ba²⁺, and Pb²⁺ in both batch mode and column mode. Sodium hydroxide treatment significantly improved the removal efficiency for all metal ions of interest compared to the untreated rice hull. The removal kinetics were extremely fast for Co, Ni, Cu, Zn, Sr, Cd, and Ba, which made the treated rice hull a …