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Articles 271 - 300 of 939
Full-Text Articles in Chemistry
Observation Of The Low-Frequency Spectrum Of The Water Trimer As A Sensitive Test Of The Water-Trimer Potential And The Dipole-Moment Surface, Raffael Schwan, Chen Qu, Devendra Mani, Nitish Pal, Gerhard Schwaab, Joel M. Bowman, Gregory S. Tschumper, Martina Havenith
Observation Of The Low-Frequency Spectrum Of The Water Trimer As A Sensitive Test Of The Water-Trimer Potential And The Dipole-Moment Surface, Raffael Schwan, Chen Qu, Devendra Mani, Nitish Pal, Gerhard Schwaab, Joel M. Bowman, Gregory S. Tschumper, Martina Havenith
Chemistry Faculty Research & Creative Works
Intermolecular interactions in bulk water are dominated by pairwise and non-pairwise cooperative interactions. While accurate descriptions of the pairwise interactions are available and can be tested by precise low-frequency spectra of the water dimer up to 550 cm−1, the same does not hold for the three-body interactions. Here, we report the first comprehensive spectrum of the water trimer in the frequency region from 70 to 620 cm−1 using helium-nanodroplet isolation and free-electron lasers. By comparison to accompanying high-level quantum calculations, the experimentally observed intermolecular bands can be assigned. The transition frequencies of the degenerate translation, the degenerate in-plane and the …
Anchoring The Hydrogen Sulfide Dimer Potential Energy Surface To Juxtapose (H2s)2 With (H2o)2, Morgan A. Perkins, Kayleigh R. Barlow, Katelyn M. Dreux, Gregory S. Tschumper
Anchoring The Hydrogen Sulfide Dimer Potential Energy Surface To Juxtapose (H2s)2 With (H2o)2, Morgan A. Perkins, Kayleigh R. Barlow, Katelyn M. Dreux, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
Twelve stationary points have been characterized on the (H2S)2 potential energy surface using the MP2 and CCSD(T) methods with large, correlation consistent basis sets. To the best of our knowledge, five of the structures have not been identified elsewhere and are presented here for the first time. A similar analysis was performed on the ten, well-known structures of the water dimer in order to facilitate direct comparisons between the corresponding (H2O)2 and (H2S)2 configurations. Harmonic vibrational frequency computations identify three (H2S)2 configurations as minima, four as transition states, …
Thermodynamic Characterization Of Free And Surface Water Of Colloidal Unimolecular Polymer (Cup) Particles Utilizing Dsc, Peng Geng, Ashish Zore, Michael R. Van De Mark
Thermodynamic Characterization Of Free And Surface Water Of Colloidal Unimolecular Polymer (Cup) Particles Utilizing Dsc, Peng Geng, Ashish Zore, Michael R. Van De Mark
Chemistry Faculty Research & Creative Works
Colloidal Unimolecular Polymer (CUP) particles are spheroidal, 3-9 nm with charged groups on the surface and a hydrophobic core, which offer a larger surface water fraction to improve the analysis of its characteristics. Differential scanning calorimetry (DSC) was performed to determine the characteristics of surface water. These properties include the amount of surface water, the layer thickness, density, specific heat of the surface water above and below the freezing point of water, melting point depression of free water, effect of charge density and particle size. The charge density on the CUP surface was varied as well as the molecular weight …
Ti2ctx Mxene-Based All-Optical Modulator, Jun Yi, Jie Li, Shuohan Huang, Longyu Hu, Lili Miao, Chujun Zhao, Shuangchun Wen, Vadym Mochalin, Apparao M. Rao
Ti2ctx Mxene-Based All-Optical Modulator, Jun Yi, Jie Li, Shuohan Huang, Longyu Hu, Lili Miao, Chujun Zhao, Shuangchun Wen, Vadym Mochalin, Apparao M. Rao
Chemistry Faculty Research & Creative Works
MXenes, a new class of 2D transition metal carbides, nitrides, and carbonitrides, have attracted much attention due to their outstanding properties. Here, we report the broadband spatial self-phase modulation of Ti2CTx MXene nanosheets dispersed in deionized water in the visible to near-infrared regime, highlighting the broadband nonlinear optical (NLO) response of Ti2CTx MXene. Using ultrafast pulsed laser excitation, the nonlinear refractive index n2 and the third-order nonlinear susceptibility (Formula presented.) of Ti2CTx MXene were measured to be ∼10−13 m2/W and ∼ 10−10 esu, respectively. Leveraging the large optical nonlinearity of Ti …
A Cascade Reaction Of Cinnamyl Azides With Acrylates Directly Generates Tetrahydro-Pyrrolo-Pyrazole Heterocycles, Angela S. Carlson, En Chih Liu, Joseph J. Topczewski
A Cascade Reaction Of Cinnamyl Azides With Acrylates Directly Generates Tetrahydro-Pyrrolo-Pyrazole Heterocycles, Angela S. Carlson, En Chih Liu, Joseph J. Topczewski
Chemistry Faculty Research & Creative Works
Developing reactions to generate complex and modular building blocks in a concise and direct fashion remains a contemporary synthetic challenge. This work describes a stereoselective cascade reaction between allylic azides and acrylates that directly generates tetrahydro-pyrrolo-pyrazole ring systems. These products contain up to four contiguous stereocenters, two of which may be tetrasubstituted carbon atoms attached to a nitrogen atom. Over 30 examples are provided with an average isolated yield of 71% (ranging from 40% to 94%). The reaction was easily scaled to use more than one gram of starting material, and the products can be readily diversified.
The Microbiota-Gut-Brain Axis Heart Shunt Part I: The French Paradox, Heart Disease And The Microbiota, M. Obrenovich, B. Siddiqui, B. Mccloskey, Prakash Reddy
The Microbiota-Gut-Brain Axis Heart Shunt Part I: The French Paradox, Heart Disease And The Microbiota, M. Obrenovich, B. Siddiqui, B. Mccloskey, Prakash Reddy
Chemistry Faculty Research & Creative Works
It has been well established that a vegetarian and polyphenol-rich diet, including fruits, vegetables, teas, juices, wine, indigestible fiber and whole grains, provide health-promoting phytochemicals and phytonutrients that are beneficial for the heart and brain. What is not well-characterized is the affect these foods have when co-metabolized within our dynamic gut and its colonizing flora. The concept of a heart shunt within the microbiota-gut-brain axis underscores the close association between brain and heart health and the so-called "French paradox" offers clues for understanding neurodegenerative and cerebrovascular diseases. Moreover, oxidation-redox reactions and redox properties of so-called brain and heart-protective foods are …
Gram-Scale Synthesis Of 2,5-Difluoro-7,7,8,8-Tetracyanoquinodimethane (F2-Tcnq), En Chih Liu, Joseph J. Topczewski
Gram-Scale Synthesis Of 2,5-Difluoro-7,7,8,8-Tetracyanoquinodimethane (F2-Tcnq), En Chih Liu, Joseph J. Topczewski
Chemistry Faculty Research & Creative Works
The molecule 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane (F2-TCNQ) is an organic semiconductor with many promising properties, including high charge mobility (μ). However, an efficient gram-scale synthesis of F2-TCNQ has not been fully documented. Herein, we report a synthesis of F2-TCNQ via a three-step sequence that affords F2-TCNQ in 58% cumulative yield. This synthesis was used to prepare more than 1 g of F2-TCNQ.
Fiber-Optic Micro-Probes For Measuring Acidity Level, Temperature, And Antigens, Yinfa Ma, Honglan Shi, Qingbo Yang, Hai Xiao
Fiber-Optic Micro-Probes For Measuring Acidity Level, Temperature, And Antigens, Yinfa Ma, Honglan Shi, Qingbo Yang, Hai Xiao
Chemistry Faculty Research & Creative Works
A pH micro-probe, a temperature micro-probe, and an immuno-based micro-probe each include a shaft for transmuting an input light signal and a tip for inserting into a cell or other substance for measuring pH, temperature, and/or antigens. The pH micro-probe and the temperature micro-probe each include a luminescent material positioned on the tip of the micro-probe. The light signal excites the luminescent material so that the luminescent material emits a luminescent light signal. The luminescent light signal has a property value dependent on the pH or temperature being measured and reflects back through the shaft for being measured by a …
A Neuro-Ontology For The Neurological Examination, Daniel B. Hier, Steven U. Brint
A Neuro-Ontology For The Neurological Examination, Daniel B. Hier, Steven U. Brint
Chemistry Faculty Research & Creative Works
Background: The Use of Clinical Data in Electronic Health Records for Machine-Learning or Data Analytics Depends on the Conversion of Free Text into Machine-Readable Codes. We Have Examined the Feasibility of Capturing the Neurological Examination as Machine-Readable Codes based on UMLS Metathesaurus Concepts. Methods: We Created a Target Ontology for Capturing the Neurological Examination using 1100 Concepts from the UMLS Metathesaurus. We Created a Dataset of 2386 Test-Phrases based on 419 Published Neurological Cases. We Then Mapped the Test-Phrases to the Target Ontology. Results: We Were Able to Map All of the 2386 Test-Phrases to 601 Unique UMLS Concepts. a …
Polyphenols In Alzheimer’S Disease And In The Gut–Brain Axis, V. Prakash Reddy, Puspa Aryal, Sara Robinson, Raheemat Rafiu, Mark Obrenovich, George Perry
Polyphenols In Alzheimer’S Disease And In The Gut–Brain Axis, V. Prakash Reddy, Puspa Aryal, Sara Robinson, Raheemat Rafiu, Mark Obrenovich, George Perry
Chemistry Faculty Research & Creative Works
Polyphenolic antioxidants, including dietary plant lignans, modulate the gut–brain axis, which involves transformation of these polyphenolic compounds into physiologically active and neuroprotector compounds (called human lignans) through gut bacterial metabolism. These gut bacterial metabolites exert their neuroprotective effects in various neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), and also have protective effects against other diseases, such as cardiovascular diseases, cancer, and diabetes. For example, enterolactone and enterodiol, the therapeutically relevant polyphenols, are formed as the secondary gut bacterial metabolites of lignans, the non-flavonoid polyphenolic compounds found in plant-based foods. These compounds are also acetylcholinesterase inhibitors and …
Revealing The Hidden Hyperfine Interactions In Ε-Iron, Dimitrios Bessas, Ilya Sergueev, Konstantin Glazyrin, Cornelius Strohm, Ilya Kupenko, Daniel G. Merkel, Gary J. Long, Fernande Grandjean, Aleksandr I. Chumakov, Rudolf Ruffer
Revealing The Hidden Hyperfine Interactions In Ε-Iron, Dimitrios Bessas, Ilya Sergueev, Konstantin Glazyrin, Cornelius Strohm, Ilya Kupenko, Daniel G. Merkel, Gary J. Long, Fernande Grandjean, Aleksandr I. Chumakov, Rudolf Ruffer
Chemistry Faculty Research & Creative Works
Herein, evidence for the long-sought finite hyperfine interaction in the high-pressure hexagonal close-packed ε-iron is gained through synchrotron radiation perturbed angular correlation spectroscopy. This method yields an energy splitting of 3.5(5)neV between the mIe= ± 1/2 and mIe = ± 3/2 nuclear sublevels of the iron-57 14.412-keV nuclear excited state at 30(1)GPa and room temperature. This energy splitting is related to a nuclear quadrupole hyperfine interaction with an electric field gradient of eq=1.2(2) x 1016V/cm2. However, there is still a possibility that the splitting of the iron-57 nuclear levels is related …
A Square Channel Vanadium Phosphite Framework As A High Voltage Cathode For Li- And Na-Ion Batteries, Prashanth Sandineni, Pranal Madria, Kartik Ghosh, Amitava Choudhury
A Square Channel Vanadium Phosphite Framework As A High Voltage Cathode For Li- And Na-Ion Batteries, Prashanth Sandineni, Pranal Madria, Kartik Ghosh, Amitava Choudhury
Chemistry Faculty Research & Creative Works
A vanadium phosphite compound, LiV(HPO3)2, has been synthesized using low-melting flux composed of phosphorous acid and lithium hydroxide. The crystal structure of the compound as refined using the Rietveld method matched with the previously reported unit cell parameters (space group: I42d, a = b = 10.5987(4), c = 9.9843(5) Å). It has a 3-dimensional open-framework structure with intersecting channels. Eight-membered ring square channels can be viewed along the c-axis and 6-membered ring channels along the a- and b-axis. The Li-ions are located in the six-membered ring channels exactly at the opening window to the eight-membered ring channels. The magnetic property …
Two Algorithms For The Reorganisation Of The Problem List By Organ System, Daniel B. Hier, Joshua Pearson
Two Algorithms For The Reorganisation Of The Problem List By Organ System, Daniel B. Hier, Joshua Pearson
Chemistry Faculty Research & Creative Works
Objective Long Problem Lists Can Be Challenging to Use. Reorganization of the Problem List by Organ System is a Strategy for Making Long Problem Lists More Manageable. Methods in a Small-Town Primary Care Setting, We Examined 4950 Unique Problem Lists over 5 Years (24 033 Total Problems and 2170 Unique Problems) from Our Electronic Health Record. All Problems Were Mapped to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) and SNOMED CT Codes. We Developed Two Different Algorithms for Reorganizing the Problem List by Organ System based on Either the ICD-10-CM or the SNOMED CT Code. Results the …
Cuinse₂ Nanotube Arrays For Efficient Solar Energy Conversion, Wipula Priya Liyanage, Manashi Nath
Cuinse₂ Nanotube Arrays For Efficient Solar Energy Conversion, Wipula Priya Liyanage, Manashi Nath
Chemistry Faculty Research & Creative Works
Highly uniform and vertically aligned p-type CuInSe2 (CISe) nanotube arrays were fabricated through a unique protocol, incorporating confined electrodeposition on lithographically patterned nanoelectrodes. This protocol can be readily adapted to fabricate nanotube arrays of other photoabsorber and functional materials with precisely controllable design parameters. Ternary CISe nanotube arrays were electrodeposited congruently from a single electrolytic bath and the resulting nanotube arrays were studied through powder X-ray diffraction as well as elemental analysis which revealed compositional purity. Detailed photoelectrochemical (PEC) characterizations in a liquid junction cell were also carried out to investigate the photoconversion efficiency. It was observed that the …
Facile One-Pot Synthesis Of Nico₂Se₄-Rgo On Ni Foam For High Performance Hybrid Supercapacitors, Bahareh Golrokh Amin, Jahangir Masud, Manashi Nath
Facile One-Pot Synthesis Of Nico₂Se₄-Rgo On Ni Foam For High Performance Hybrid Supercapacitors, Bahareh Golrokh Amin, Jahangir Masud, Manashi Nath
Chemistry Faculty Research & Creative Works
A facile, innovative synthesis for the fabrication of NiCo2Se4-rGO on a Ni foam nanocomposite via a simple hydrothermal reaction is proposed. The as-prepared NiCo2Se4-rGO@Ni foam electrode was tested through pxrd, TEM, SEM, and EDS to characterize the morphology and the purity of the material. The bimetallic electrode exhibited outstanding electrochemical performance with a high specific capacitance of 2038.55 F g-1 at 1 A g-1. NiCo2Se4-rGO@Ni foam exhibits an extensive cycling stability after 1000 cycles by retaining 90% of its initial capacity. A superior energy density …
Enhanced Piezoresponse And Nonlinear Optical Properties Of Fluorinated Self-Assembled Peptide Nanotubes, Soma Khanra, Sandra V. Vassiliades, Wendel A. Alves, Kaidi Yang, Rainer Glaser, Kartik Ghosh, Payal Bhattacharya, Ping Yu, Suchismita Guha
Enhanced Piezoresponse And Nonlinear Optical Properties Of Fluorinated Self-Assembled Peptide Nanotubes, Soma Khanra, Sandra V. Vassiliades, Wendel A. Alves, Kaidi Yang, Rainer Glaser, Kartik Ghosh, Payal Bhattacharya, Ping Yu, Suchismita Guha
Chemistry Faculty Research & Creative Works
Self-assembled L,L-diphenylalanine (FF) nanostructures offer an attractive platform for photonics and nonlinear optics. The nonlinear optical (NLO) coefficients of FF nanotubes depend on the diameter of the tube [S. Khanra et al. Phys. Chem. Chem. Phys. 19(4), 3084-3093 (2017)]. To further enhance the NLO properties of FF, we search for structural modifications. Here, we report on the synthesis of fluorinated FF dipeptides by replacing one ortho-hydrogen atom in each of the phenyl groups of FF by a fluorine atom. Density-functional theoretical calculations yield insights into minimum energy conformers of fluorinated FF (Fl-FF). Fl-FF self-assembles akin to FF into micron-length tubes. …
Novel Highly Porous Ceramic And Metal Aerogels From Xerogel Powder Precursors, And Methods For Their Production And Use, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed, Parwani Rewatkar, Tahereh Taghvaee
Novel Highly Porous Ceramic And Metal Aerogels From Xerogel Powder Precursors, And Methods For Their Production And Use, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed, Parwani Rewatkar, Tahereh Taghvaee
Chemistry Faculty Research & Creative Works
The present invention discloses novel methods for producing highly porous ceramic and/or metal aerogel monolithic objects that are hard, sturdy, and resistant to high temperatures. These methods comprise preparing nanoparticulate oxides of metals and/or metalloids via a step of vigorous stirring to prevent gelation, preparing polymer-modified xerogel powder compositions by reacting said nanoparticulate oxides with one or more polyfunctional monomers, compressing said polymer-modified xerogel powder compositions into shaped compacts, and carbothermal conversion of the shaped xerogel compacts via pyrolysis to provide the highly porous ceramic and/or metal aerogel monolithic objects that have the same shapes as to their corresponding xerogel …
Co-Localization Of Dna I-Motif-Forming Sequences And 5-Hydroxymethyl-Cytosines In Human Embryonic Stem Cells, Yogini P. Bhavsar-Jog, Eric Van Dornshuld, Tracy A. Brooks, Gregory S. Tschumper, Randy M. Wadkins
Co-Localization Of Dna I-Motif-Forming Sequences And 5-Hydroxymethyl-Cytosines In Human Embryonic Stem Cells, Yogini P. Bhavsar-Jog, Eric Van Dornshuld, Tracy A. Brooks, Gregory S. Tschumper, Randy M. Wadkins
Chemistry Faculty Research & Creative Works
G-quadruplexes (G4s) and i-motifs (iMs) are tetraplex DNA structures. Sequences capable of forming G4/iMs are abundant near the transcription start sites (TSS) of several genes. G4/iMs affect gene expression in vitro. Depending on the gene, the presence of G4/iMs can enhance or suppress expression, making it challenging to discern the underlying mechanism by which they operate. Factors affecting G4/iM structures can provide additional insight into their mechanism of regulation. One such factor is epigenetic modification. The 5-hydroxymethylated cytosines (5hmCs) are epigenetic modifications that occur abundantly in human embryonic stem cells (hESC). The 5hmCs, like G4/iMs, are known to participate in …
Electrochemistry Of Illusive Barbosalite, Fe²⁺Fe³⁺ 2(Po₄)₂(Oh)₂: An Iron Phosphate Related To Lipscombite Structure, Prashanth Sandineni, Kartik Ghosh, Amitava Choudhury
Electrochemistry Of Illusive Barbosalite, Fe²⁺Fe³⁺ 2(Po₄)₂(Oh)₂: An Iron Phosphate Related To Lipscombite Structure, Prashanth Sandineni, Kartik Ghosh, Amitava Choudhury
Chemistry Faculty Research & Creative Works
Barbosalite, an iron hydroxy-phosphate belonging to the family of Lazulite has been synthesized using hydrothermal route and its electrochemical property is investigated for the first time with respect to Li-ion batteries. The structure, as determined from single-crystal X-ray diffraction data, built up of undulating layers of FeO6 octahedra, consisting of trimers and PO4 tetrahedral units. Magnetic susceptibility measurements show predominant overall anti-ferromagnetic interactions and room temperature 57Fe Mössbauer spectroscopic studies confirm the mixed 3+ and 2+ oxidation states of Fe in the compound. The compound is stable up to 400°C and undergo facile electrochemical lithium insertion. Galvanostatic charge-discharge …
State-To-State Inelastic Rotational Cross Sections In Five-Atom Systems With The Multiconfiguration Time Dependent Hartree Method, Steve Ndengue, Yohann Scribano, Fabien Gatti, Richard Dawes
State-To-State Inelastic Rotational Cross Sections In Five-Atom Systems With The Multiconfiguration Time Dependent Hartree Method, Steve Ndengue, Yohann Scribano, Fabien Gatti, Richard Dawes
Chemistry Faculty Research & Creative Works
We present a MultiConfiguration Time Dependent Hartree (MCTDH) method as an attractive alternative approach to the usual quantum close-coupling method that approaches some computational limits in the calculation of rotational excitation (and de-excitation) between polyatomic molecules (here collisions between triatomic and diatomic rigid molecules). We have performed a computational investigation of the rotational (de-)excitation of the benchmark rigid rotor H2O-H2 system on a recently developed Potential Energy Surface of the complex using the MCTDH method. We focus here on excitations and de-excitations from the 000, 111, and 110 states of H2 …
Double-Click Enables Synthesis Of Chemical Libraries For Drug Discovery, Joseph J. Topczewski, En Chih Liu
Double-Click Enables Synthesis Of Chemical Libraries For Drug Discovery, Joseph J. Topczewski, En Chih Liu
Chemistry Faculty Research & Creative Works
No abstract provided.
Low-Cost, Ambient-Dried, Superhydrophobic, High Strength, Thermally Insulating, And Thermally Resilient Polybenzoxazine Aerogels, Sadeq Malakooti, Guoqiang Qin, Chandana Mandal, Rushi Soni, Tahereh Taghvaee, Yao Ren, Huiluo Chen, Nicholas Tsao, James Shiao, Shameek Sushil Kulkarni, Chariklia Sotiriou-Leventis, Nicholas Leventis, Hongbing Lu
Low-Cost, Ambient-Dried, Superhydrophobic, High Strength, Thermally Insulating, And Thermally Resilient Polybenzoxazine Aerogels, Sadeq Malakooti, Guoqiang Qin, Chandana Mandal, Rushi Soni, Tahereh Taghvaee, Yao Ren, Huiluo Chen, Nicholas Tsao, James Shiao, Shameek Sushil Kulkarni, Chariklia Sotiriou-Leventis, Nicholas Leventis, Hongbing Lu
Chemistry Faculty Research & Creative Works
A family of ambient-dried poly benzoxazine aerogels is prepared with a facile and scalable process as a high-performance polymeric aerogel with strong and robust thermomechanical properties at elevated temperatures. Those materials are inherently flame-retardant and superhydrophobic over the entire bulk density range (0.24-0.46 g cm-3). In addition, they are mechanically strong with strengths (e.g., 1 MPa at 0.24 g cm-3 at room temperature) higher than those of other high-performance aerogels of similar density, including polyimide and polyamide (Kevlar-like) aerogels as well as polymer-cross-linked X-silica and X-Vanadia aerogels, at a significantly lower cost. Furthermore, unlike most other glassy polymeric materials, the …
Computational Study Of The Ro-Vibrational Spectrum Of Co-Co₂, Eduardo Castro-Juarez, Xiao-Gang Wang, Tucker Carrington Jr., Ernesto Quintas-Sánchez, Richard Dawes
Computational Study Of The Ro-Vibrational Spectrum Of Co-Co₂, Eduardo Castro-Juarez, Xiao-Gang Wang, Tucker Carrington Jr., Ernesto Quintas-Sánchez, Richard Dawes
Chemistry Faculty Research & Creative Works
An accurate ab initio ground-state intermolecular potential energy surface (PES) was determined for the CO-CO2 van der Waals dimer. The Lanczos algorithm was used to compute rovibrational energies on this PES. For both the C-in and O-in T-shaped isomers, the fundamental transition frequencies agree well with previous experimental results. We confirm that the in-plane states previously observed are geared states. In addition, we have computed and assigned many other vibrational states. The rotational constants we determine from J = 1 energy levels agree well with their experimental counterparts. Planar and out-of-plane cuts of some of the wavefunctions we compute …
Enhanced Flocculation Using Drinking Water Treatment Plant Sedimentation Residual Solids, Sandhya Rao Poleneni, Enos Inniss, Honglan Shi, John Yang, Bin Hua, Joseph Clamp
Enhanced Flocculation Using Drinking Water Treatment Plant Sedimentation Residual Solids, Sandhya Rao Poleneni, Enos Inniss, Honglan Shi, John Yang, Bin Hua, Joseph Clamp
Chemistry Faculty Research & Creative Works
Inefficient removal of total organic carbon (TOC) leads to the formation of carcinogenic disinfection by-products (DBPs) when a disinfectant is added. This study is performed in an effort to develop a simple, non-invasive, and cost-effective technology that will effectively lower organic precursors by having water utilities reuse their treatment residual solids. Jar tests are used to simulate drinking water treatment processes with coagulants-aluminum sulfate (alum), poly-aluminum chloride (PACl), and ferric chloride and their residual solids. Ten coagulant-to-residual (C/R) ratios are tested with water from the Missouri River at Coopers Landing in Columbia, MO versus alluvial ground waters. This treatment results …
The Ideal And Real Gas Heat Capacity Of Cesium Atoms At High Temperatures, Louis Biolsi, Michael Biolsi
The Ideal And Real Gas Heat Capacity Of Cesium Atoms At High Temperatures, Louis Biolsi, Michael Biolsi
Chemistry Faculty Research & Creative Works
The Ideal Gas Heat Capacity, Cp, of Cesium Atoms is Calculated to High Temperatures using Statistical Mechanics. There Are a Large Number of Electronic States in the State Sum that Determines the Partition Function: 174 Known Levels for Cesium Atoms Below the First Ionization Potential. Thus, at High Temperatures, Cp Becomes Very Large Unless the Number of Contributing States is Constrained. Two Arguments Are Used to Do This. First, at High Temperatures, the Increased Size of the Atoms Constrains the Sum (Bethe Method). Second, the Existence of Interacting Charged Species at Higher Temperatures, Which Lowers the Ionization …
Additive-Free Palladium-Catalyzed Decarboxylative Cross-Coupling Of Aryl Chlorides, Ryan A. Daley, En Chih Liu, Joseph J. Topczewski
Additive-Free Palladium-Catalyzed Decarboxylative Cross-Coupling Of Aryl Chlorides, Ryan A. Daley, En Chih Liu, Joseph J. Topczewski
Chemistry Faculty Research & Creative Works
The cross-coupling of sodium (hetero)aryl carboxylates with (hetero)aryl chlorides proceed with 1 mol % palladium catalyst and does not require inorganic base, silver salts, or copper salts. This coupling uses two low energy partners, and the only stoichiometric byproducts are carbon dioxide and sodium chloride. The substrate scope includes less activated aryl chlorides and carboxylates (>25 examples). The palladium loading could be reduced to 0.1 mol %, and Buchwald-style precatalysts could be used.
Kinetic Resolution Of Cyclic Secondary Azides, Using An Enantioselective Copper-Catalyzed Azide-Alkyne Cycloaddition, Juliana R. Alexander, Amy A. Ott, En Chih Liu, Joseph J. Topczewski
Kinetic Resolution Of Cyclic Secondary Azides, Using An Enantioselective Copper-Catalyzed Azide-Alkyne Cycloaddition, Juliana R. Alexander, Amy A. Ott, En Chih Liu, Joseph J. Topczewski
Chemistry Faculty Research & Creative Works
An enantioselective copper-catalyzed azide-alkyne cycloaddition (E-CuAAC) is reported by kinetic resolution. Chiral triazoles were isolated in high yield with limiting alkyne (up to 97:3 enantiomeric ratio (er)). A range of substrates were tolerated (>30 examples), and the reaction was scaled to >1 g. The er of a triazole product could be enhanced by recrystallization and the recovered scalemic azide could be racemized and recycled. Recycling the azide allows efficient use of the undesired azide enantiomer.
The Transformative Possibilities Of The Microbiota And Mycobiota For Health, Disease, Aging, And Technological Innovation, Lucas Jones, Jessica Kumar, Adil Mistry, Thriveen Sankar Chittoor Mana, George Perry, Prakash Reddy, Mark Obrenovich
The Transformative Possibilities Of The Microbiota And Mycobiota For Health, Disease, Aging, And Technological Innovation, Lucas Jones, Jessica Kumar, Adil Mistry, Thriveen Sankar Chittoor Mana, George Perry, Prakash Reddy, Mark Obrenovich
Chemistry Faculty Research & Creative Works
The gut microbiota is extremely important for the health of the host across its lifespan. Recent studies have elucidated connections between the gut microbiota and neurological disease and disorders such as depression, anxiety, Alzheimer's disease (AD), autism, and a host of other brain illnesses. Dysbiosis of the normal gut flora can have negative consequences for humans, especially throughout key periods during our lifespan as the gut microbes change with age in both phenotype and number of bacterial species. Neurologic diseases, mental disorders, and euthymic states are influenced by alterations in the metabolites produced by gut microbial milieu. We introduce a …
Facile And Label-Free Electrochemical Biosensors For Microrna Detection Based On Dna Origami Nanostructures, Shuo Han, Wenyan Liu, Shuo Yang, Risheng Wang
Facile And Label-Free Electrochemical Biosensors For Microrna Detection Based On Dna Origami Nanostructures, Shuo Han, Wenyan Liu, Shuo Yang, Risheng Wang
Chemistry Faculty Research & Creative Works
MicroRNAs (miRNAs) have emerged as the promising molecular biomarkers for early diagnosis and enhanced understanding of the molecular pathogenesis of cancers as well as certain diseases. Here, a facile, label-free, and amplification-free electrochemical biosensor was developed to detect miRNA by using DNA origami nanostructure-supported DNA probes, with methylene blue (MB) serving as the hybridization redox indicator, for the first time. Specifically, the use of cross-shaped DNA origami nanostructures containing multiple single-stranded DNA probes at preselected locations on each DNA nanostructure could increase the accessibility and the recognition efficiency of the probes (due to the rational controlled density of DNA probes). …
Iron Detection And Remediation With A Functionalized Porous Polymer Applied To Environmental Water Samples, Sumin Lee, Adam Uliana, Mercedes K. Taylor, Gary J. Long, Fernande Grandjean, For Full List Of Authors, See Publisher's Website.
Iron Detection And Remediation With A Functionalized Porous Polymer Applied To Environmental Water Samples, Sumin Lee, Adam Uliana, Mercedes K. Taylor, Gary J. Long, Fernande Grandjean, For Full List Of Authors, See Publisher's Website.
Chemistry Faculty Research & Creative Works
Iron is one of the most abundant elements in the environment and in the human body. As an essential nutrient, iron homeostasis is tightly regulated, and iron dysregulation is implicated in numerous pathologies, including neuro-degenerative diseases, atherosclerosis, and diabetes. Endogenous iron pool concentrations are directly linked to iron ion uptake from environmental sources such as drinking water, providing motivation for developing new technologies for assessing iron(ii) and iron(iii) levels in water. However, conventional methods for measuring aqueous iron pools remain laborious and costly and often require sophisticated equipment and/or additional processing steps to remove the iron ions from the original …