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Articles 121 - 150 of 174
Full-Text Articles in Other Chemistry
Patent: Fusion Proteins For Treating Metabolic Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Norio Hamamatsu, Stuart Licht, Stephen Craig Weldon
Patent: Fusion Proteins For Treating Metabolic Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Norio Hamamatsu, Stuart Licht, Stephen Craig Weldon
Chemistry Faculty Publications
The invention relates to the identification of fusion proteins comprising polypeptide and protein variants of fibroblast growth factor 21 (FGF21) with improved pharmaceutical properties. Also disclosed are methods for treating FGF21 associated disorders, including metabolic conditions.
Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan
Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan
Chemistry Faculty Publications
The current article reports in detail the preparation of two phosphonoterephthalic acids: 2-phosphonoterephthalic acid (1) and 2,5-diphosphonoterephthalic acid (2). Efficient, scalable syntheses have been developed for both compounds based on Pd-catalyzed coupling reactions of iodinated terephthalate esters. Phosphonoterephthalic acids are potentially useful as flame-retardant additives or as monomers for the construction of acid-pendant polymer chains.
Reaction Between Polyol-Esters And Phosphate Esters In The Presence Of Metal Carbides, David W. Johnson, Carolyn Iacullo, John E. Hils
Reaction Between Polyol-Esters And Phosphate Esters In The Presence Of Metal Carbides, David W. Johnson, Carolyn Iacullo, John E. Hils
Chemistry Faculty Publications
The reaction of metal carbides with polyol esters found in aerospace lubricants and phosphate esters commonly used as additives was investigated. Carbides were of particular interest since modern materials under consideration at high temperature bearings have surfaces that are primarily metal carbides. Vanadium and chromium carbide were found to react with the ester and phosphate ester by a transesterification reaction, producing an alkyl phosphate which is less stable than the aromatic phosphate esters. In the process, the metal carbide is converted to the metal phosphate and metal polyphosphate, evidenced by the infrared and Raman spectra of the solid residue and …
Broadband Fourier Transform Rotational Spectroscopy For Structure Determination: The Water Heptamer, Cristóbal Pérez, Simon Lobsiger, Nathan A. Seifert, Daniel P. Zaleski, Berhane Temelso, George C. Shields, Zbigniew Kisiel, Brooks H. Pate
Broadband Fourier Transform Rotational Spectroscopy For Structure Determination: The Water Heptamer, Cristóbal Pérez, Simon Lobsiger, Nathan A. Seifert, Daniel P. Zaleski, Berhane Temelso, George C. Shields, Zbigniew Kisiel, Brooks H. Pate
Faculty Journal Articles
Over the recent years chirped-pulse, Fourier-transform microwave (CP-FTMW) spectrometers have chan- ged the scope of rotational spectroscopy. The broad frequency and large dynamic range make possible structural determinations in molecular systems of increasingly larger size from measurements of heavy atom (13C, 15N, 18O) isotopes recorded in natural abundance in the same spectrum as that of the parent isotopic species. The design of a broadband spectrometer operating in the 2–8 GHz frequency range with further improvements in sensitivity is presented. The current CP-FTMW spectrometer performance is benchmarked in the analyses of the rotational spectrum of the water …
Controlled Transformation Of Nanoparticles With Tunable Surface Plasmon Resonance, Nimer Murshid
Controlled Transformation Of Nanoparticles With Tunable Surface Plasmon Resonance, Nimer Murshid
Theses and Dissertations (Comprehensive)
This thesis reports key findings in the synthesis and transformation of silver nanoparticles (AgNPs) with pentagonal symmetries. The main focus of the thesis work is on the synthesis of silver decahedral nanoparticles (AgDeNPs) and their transformation into larger AgDeNPs and silver pentagonal rod nanoparticles (AgPRNPs). In another direction, produced AgNPs were stabilized by gold plating. In a one-stage photochemical synthesis of AgDeNPs (pentagonal bipyramid, J13 solid), oxidative etching by hydrogen peroxide was implemented to achieve complete conversion of the small silver platelet precursor NPs. For convenient laboratory synthesis of high-purity size-selected AgDeNPs, we have also adapted LEDs as a …
Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman
Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman
Chemistry Faculty Publications
The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …
Patent: Methods Of Treating Fgf21-Associated Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Bernhard Hubert Geierstanger, Norio Hamamatsu, Stuart Licht, Andreas Loew, Stephen Craig Weldon
Patent: Methods Of Treating Fgf21-Associated Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Bernhard Hubert Geierstanger, Norio Hamamatsu, Stuart Licht, Andreas Loew, Stephen Craig Weldon
Chemistry Faculty Publications
The invention relates to the identification of new polypeptide and protein variants of fibroblast growth factor 21 (FGF21) that have improved pharmaceutical properties. Also disclosed are methods for treating FGF21-associated disorders, includ ing metabolic conditions.
Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown
Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown
Symposium 2012
Community associated Staphylococcus aureus (strain MSSA476) is a gram positive cocci capable of infecting many different parts of the body and known to cause serious infections that can be fatal, such as bacterial arthritis and acute endocarditis. To find effective ways of fighting against CA-MRSA strains we must learn more about their ability to infect. The focus of this study was cloning and characterization of a protein referred to as SAS0754. The size of SAS0754 is 340 amino acids and the gene sequence is 1023 nucleotides. The hypothetical function of this protein is that it is an extracellular matrix binding …
A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch
A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch
Symposium 2012
In our synthetic efforts toward the alkaloid phantasmidine, we required a convenient source of the title compound. Herein, we describe a short synthesis of 2,6-dichlorohomonicotinic acid by direct allylation of 2,6-dichloropyridine with LDA/allyl chloride, followed by permanganate oxidation of the side chain [figure1]. Yields for the allylation are high, while permanganate oxidation required more adjustment. Successful conditions require the modest acidification of the mixture with acetic acid and cleanup by acid base workup. No chromatography is needed.
Convenient Parallel Synthesis Of Alkyl- And Aryl-S-Tert-Butyl Thiothers, Rebecca Norcross, Jessica Stanfield, Richard W. Fitch
Convenient Parallel Synthesis Of Alkyl- And Aryl-S-Tert-Butyl Thiothers, Rebecca Norcross, Jessica Stanfield, Richard W. Fitch
Symposium 2012
While preparing novel cysteine derivatives as oxidation catalysts, we needed S-tert-butylcysteine. We also examined acid-promoted tert-butylation of thiols using tert-butanol as reagent and solvent. While cysteine and aminoethanethiol work well using tBuOH in 4M HCl, other thiols fail in the aqueous environment and aerobic conditions. We examined a variety of aliphatic and aromatic thiols in tBuOH with H2SO4 catalysis and found that argon sparging and the use of 1 eq of acid led to good yields in a parallel format.
Dynamic Light Scattering And Microelectrophoresis: Main Prospects And Limitations, Vuk Uskoković
Dynamic Light Scattering And Microelectrophoresis: Main Prospects And Limitations, Vuk Uskoković
Pharmacy Faculty Articles and Research
Microelectrophoresis based on the dynamic light scattering (DLS) effect has been a major tool for assessing and controlling the conditions for stability of colloidal systems. However, both the DLS methods for characterization of the hydrodynamic size of dispersed submicron particles and the theory behind the electrokinetic phenomena are associated with fundamental and practical approximations that limit their sensitivity and information output. Some of these fundamental limitations, including the spherical approximation of DLS measurements and an inability of microelectrophoretic analyses of colloidal systems to detect discrete charges and differ between differently charged particle surfaces due to rotational diffusion and particle orientation …
Pegylated Silicon Nanowire Coated Silica Microparticles For Drug Delivery Across Intestinal Epithelium, Vuk Uskoković, Phin-Peng Lee, Laura Walsh, Kathleen Fischer, Tejal Dasai
Pegylated Silicon Nanowire Coated Silica Microparticles For Drug Delivery Across Intestinal Epithelium, Vuk Uskoković, Phin-Peng Lee, Laura Walsh, Kathleen Fischer, Tejal Dasai
Pharmacy Faculty Articles and Research
Composite particles made by growing nanoscopic silicon wires from the surface of monodispersed, microsized silica beads were tested in this study for their ability to affect the integrity and permeability of an epithelial cell layer. Polyethylene glycol (PEG) is known to sterically stabilize particles and prevent protein binding; as such, it is a routine way to impart in vivo longevity to drug carriers. The effect of the silica beads, both with and without silicon nanowires and PEG, on the disruption of the tight junctions in Caco-2 cells was evaluated by means of: (a) analysis of the localization of zonula occludens-1 …
Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan
Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan
Chemistry Faculty Publications
The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were successfully employed in the preparation of phosphonic and boronic esters and acids. The latter were tested for heat release with a microcombustion calorimeter (ASTM D7309) to determine the potential for heat release reduction of these flame retardant molecules. The results showed that the addition of boronic or phosphonic acids greatly lowered the heat release, due to a condensed phase (char formation) mechanism. Adding ester groups to the boronic acids or …
A New, Simple, Green And One-Pot Four-Component Synthesis Of Bare And Poly(Α, Γ, L-Glutamic Acid) Capped Silver Nanoparticles, Magdalena Stevanović, Igor Savanović, Vuk Uskoković, Srečo D. Škapin, Ines Bračko, Uroš Jovanović, Dragan Uskoković
A New, Simple, Green And One-Pot Four-Component Synthesis Of Bare And Poly(Α, Γ, L-Glutamic Acid) Capped Silver Nanoparticles, Magdalena Stevanović, Igor Savanović, Vuk Uskoković, Srečo D. Škapin, Ines Bračko, Uroš Jovanović, Dragan Uskoković
Pharmacy Faculty Articles and Research
A simple and green chemical method has been developed to synthesize stable bare and capped silver nanoparticles based on the reduction of silver ions by glucose and capping by poly(α,γ,Lglutamic acid) (PGA). The use of ammonia during synthesis was avoided. PGA has had a dual role in the synthesis and was used as a capping agent to make the silver nanoparticle more biocompatible and to protect the nanoparticles from agglomerating in the liquid medium. The synthesized PGA-capped silver nanoparticles in the size range 5–45 nm were stable over long periods of time, without signs of precipitation. Morphological examination has shown …
The Tetrafluoroborate Salt Of 4-Methoxybenzyl N-2-(Dimethylamino)Ethyl-N-Nitrosocarbamate: Synthesis, Crystal Structure And Dft Calculations, Helene Hedian, Vladimir Benin
The Tetrafluoroborate Salt Of 4-Methoxybenzyl N-2-(Dimethylamino)Ethyl-N-Nitrosocarbamate: Synthesis, Crystal Structure And Dft Calculations, Helene Hedian, Vladimir Benin
Chemistry Faculty Publications
The tetrafluoroborate salt of 4-methoxybenzyl N-2-(dimethylamino)ethyl-N-nitrosocarbamate was prepared in two steps, via the corresponding carbamate. Its crystal structure is monoclinic, space group P21/c. The unit cell dimensions are: a = 19.499(8) Å, b = 5.877(3) Å, c = 15.757(7) Å, α = 90°, β = 110.019(7)°, γ = 90°, V = 1696.5(12) Å3, Z = 4. The structure exhibits an unexpected, pseudo-gauche conformation with respect to the C2–C3 bond, due to a stabilizing hydrogen bond between the carbonyl oxygen (O1) and the hydrogen atom at the trialkylammonium center (H3n), with a distance between them of …
Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson
Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson
Chemistry Faculty Publications
Recent advances in lasers and detector technologies and the development of low-cost instruments and fiber-optic probes have brought about an explosion in the lubrication systems being studied by Raman spectroscopy. This article provides examples of the use of Raman spectroscopy in the study of lubrication phenomena, including the characterization of liquid lubricants, lubricant additives, and solid lubricants; the study of vapor-phase lubrication; and the use of coated nanoparticles as lubricants.
Communication: Bubbles, Crystals, And Laser-Induced Nucleation, Brandon C. Knott, Jerry L. Larue, Alec M. Wodtke, Michael F. Doherty, Baron Peters
Communication: Bubbles, Crystals, And Laser-Induced Nucleation, Brandon C. Knott, Jerry L. Larue, Alec M. Wodtke, Michael F. Doherty, Baron Peters
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Short intense laser pulses of visible and infrared light can dramatically accelerate crystal nucleation from transparent solutions; previous studies invoke mechanisms that are only applicable for nucleation of ordered phases or high dielectric phases. However, we show that similar laser pulses induce CO2bubblenucleation in carbonated water. Additionally, in water that is cosupersaturated with argon and glycine, argon bubbles escaping from the water can induce crystal nucleation without a laser. Our findings suggest a possible link between laser-induced nucleation of bubbles and crystals.
A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride, Scott Simmons, Albert Fratini, Vladimir Benin
A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride, Scott Simmons, Albert Fratini, Vladimir Benin
Chemistry Faculty Publications
The title compound, sodium bis(6-carboxy-1-hydroxy-3-oxo-1,3-dihydro-2,1-benzoxaborol-1-yl)oxidanium, Na+·C16H15B2O13-, was prepared in two steps from 2-bromo-p-xylene. Its crystal structure was determined at 140 K and has triclinic (P) symmetry. The compound presents a unique structural motif, including two units of the cyclic anhydride of boronoterephthalic acid, joined by a protonated, and thereby trivalent, oxonium center. Association in the crystal is realized by complementary hydrogen bonding of the carboxyl groups, as well as by coordination of the sodium cations to the oxygen centers on the five-membered rings.
Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin
Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin
Chemistry Faculty Publications
Moringa oleifera, sometimes called the “Miracle Tree,” has received international attention for its potential to improve health in impoverished tropical areas. In addition to high vitamin content in the leaves and pods, the tree contains compounds with antioxidant and antibacterial properties. This study focused on the theoretical investigation of the suggested structure of one antibacterial compound, “pterygospermin,” whose existence was proposed after some studies of the roots of M. oleifera. The structure of pterygospermin was first proposed by a research group working in the 1950s, but later studies have not found evidence of this compound and have instead …
Dynamic Light Scattering And Zeta Potential Of Colloidal Mixtures Of Amelogenin And Hydroxyapatite In Calcium And Phosphate Rich Ionic Milieus, Vuk Uskoković, Roselyn Odsinada, Sonia Djordjevic, Stefan Habelitz
Dynamic Light Scattering And Zeta Potential Of Colloidal Mixtures Of Amelogenin And Hydroxyapatite In Calcium And Phosphate Rich Ionic Milieus, Vuk Uskoković, Roselyn Odsinada, Sonia Djordjevic, Stefan Habelitz
Pharmacy Faculty Articles and Research
The concept of zeta-potential has been used for more than a century as a basic parameter in controlling the stability of colloidal suspensions, irrespective of the nature of their particulate ingredients – organic or inorganic. There are prospects that self-assembly of peptide species and the protein-mineral interactions related to biomineralization may be controlled using this fundamental physicochemical parameter. In this study, we have analyzed the particle size and zeta-potential of the full-length recombinant human amelogenin (rH174), the main protein of the developing enamel matrix, in the presence of calcium and phosphate ions and hydroxyapatite (HAP) particles. As calcium and phosphate …
The Impact Of Driving Conditions On Phev Battery Performance, Nathan Christensen, John Patten, Steven Srivastava, Gary P. Nola
The Impact Of Driving Conditions On Phev Battery Performance, Nathan Christensen, John Patten, Steven Srivastava, Gary P. Nola
Green Manufacturing Research Journal
The battery performance of a modified Prius with a 5 kWh plug-in battery was documented for a year to determine the impact of environmental conditions and user attributes on vehicle performance. Both fuel economy and pure electrical efficiency were compared to ambient temperature. The fuel economy has a positive relationship with ambient temperature until approximately 70˚F where the efficiency begins to drop. Electrical performance has a positive linear relationship with ambient temperature. With the emergence of electric vehicles (EVs) and PHEVs from a variety of automotive manufacturers, information on EV and PHEV performance for consumers will become more important.
Vibrationally Promoted Electron Emission At A Metal Surface: Electron Kinetic Energy Distributions, Jerry L. Larue, Tim Schäfer, Daniel Matsiev, Luis Velarde, N. Hendrick Nahler, Daniel J. Auerbach, Alec M. Wodtke
Vibrationally Promoted Electron Emission At A Metal Surface: Electron Kinetic Energy Distributions, Jerry L. Larue, Tim Schäfer, Daniel Matsiev, Luis Velarde, N. Hendrick Nahler, Daniel J. Auerbach, Alec M. Wodtke
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We report the first direct measurement of the kinetic energy of exoelectrons produced by collisions of vibrationally excited molecules with a low work function metal surface exhibiting electron excitations of 64% (most probable) and 95% (maximum) of the initial vibrational energy. This remarkable efficiency for vibrational-to-electronic energy transfer is in good agreement with previous results suggesting the coupling of multiple vibrational quanta to a single electron.
Site-Specific Photocatalytic Splitting Of Methanol On Tio2(110), Chuanyao Zhou, Zefeng Ren, Shijing Tan, Zhibo Ma, Xinchun Mao, Dongxu Dai, Hongjun Fan, Xueming Yang, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Zhou Wang, Zhenyu Li, Bing Wang, Jinlong Yang, Jianguo Hou
Site-Specific Photocatalytic Splitting Of Methanol On Tio2(110), Chuanyao Zhou, Zefeng Ren, Shijing Tan, Zhibo Ma, Xinchun Mao, Dongxu Dai, Hongjun Fan, Xueming Yang, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Zhou Wang, Zhenyu Li, Bing Wang, Jinlong Yang, Jianguo Hou
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Clean hydrogen production is highly desirable for future energy needs, making the understanding of molecular-level phenomena underlying photocatalytic hydrogen production both fundamentally and practically important. Water splitting on pure TiO2 is inefficient, however, adding sacrificial methanol could significantly enhance the photocatalyzed H2 production. Therefore, understanding the photochemistry of methanol on TiO2 at the molecular level could provide important insights to its photocatalytic activity. Here, we report the first clear evidence of photocatalyzed splitting of methanol on TiO2 derived from time-dependent two-photon photoemission (TD-2PPE) results in combination with scanning tunneling microscopy (STM). STM tip induced molecular manipulation …
A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang
A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
A surface femtosecond two-photon photoemission (2PPE) spectrometer devoted to the study of ultrafast excited electron dynamics and photochemical kinetics on metal and metal oxide surfaces has been constructed. Low energy photoelectrons are measured using a hemispheri- cal electron energy analyzer with an imaging detector that allows us to detect the energy and the angular distributions of the photoelectrons simultaneously. A Mach-Zehnder interferom- eter was built for the time-resolved 2PPE (TR-2PPE) measurement to study ultrafast surface excited electron dynamics, which was demonstrated on the Cu(111) surface. A scheme for measuring time-dependent 2PPE (TD-2PPE) spectra has also been developed for studies of …
Beta-Peptides With Improved Affinity For Hdm2 And Hdmx, Elizabeth A. Harker, Douglas S. Daniels, Danielle A. Guarracino, Alanna S. Schepartz
Beta-Peptides With Improved Affinity For Hdm2 And Hdmx, Elizabeth A. Harker, Douglas S. Daniels, Danielle A. Guarracino, Alanna S. Schepartz
Chemistry Faculty Publications
We previously described a series of 314-helical β-peptides that bind the hDM2 protein and inhibit its interaction with a p53-derived peptide in vitro. Here we present a detailed characterization of the interaction of these peptides with hDM2 and report two new β-peptides in which non-natural side chains have been substituted into the hDM2-recognition epitope. These peptides feature both improved affinity and inhibitory potency in fluorescence polarization and ELISA assays. Additionally, one of the new β-peptides also binds the hDM2-related protein, hDMX, which has been identified as another key therapeutic target for activation of the p53 pathway in tumors.
Preparation And Characterization Of Some Substituted Benzyl N-Nitrosocarbamates Containing An N-2-(Methylthio)Ethyl Or A Bis(2-Aminoethyl)Sulfide Functionality, Satya Venkata, Eric Shamo, Vladimir Benin
Preparation And Characterization Of Some Substituted Benzyl N-Nitrosocarbamates Containing An N-2-(Methylthio)Ethyl Or A Bis(2-Aminoethyl)Sulfide Functionality, Satya Venkata, Eric Shamo, Vladimir Benin
Chemistry Faculty Publications
The synthesis and characterization of some substituted benzyl N-nitrosocarbamates with an N-2-(methylthio)ethyl or a bis(2-aminoethyl)sulfide functionality is reported, as a part of a long-term goal to design and prepare novel photolabile structures that could be used as substances for controlled release of alkylating and/or crosslinking agents. The synthesis was accomplished by reaction of benzyl chloroformates with the corresponding amines, resulting in the preparation of carbamates. The latter were subsequently nitrosated, utilizing two different N-nitrosation methods, to yield the target structures.
Patent: Cell-Permeable Miniature Proteins, Alanna S. Schepartz, Douglas S. Daniels, Betsy Smith
Patent: Cell-Permeable Miniature Proteins, Alanna S. Schepartz, Douglas S. Daniels, Betsy Smith
Chemistry Faculty Publications
Abstract: The present invention generally relates to miniature proteins, including miniature proteins that are permeable to cells. Certain aspects of the invention are generally related to miniature proteins, such as avian pancreatic polypeptide (aPP), modified such that the miniature proteins are permeable to cells. For instance, a portion of the aPP, such as the alpha helix region and/or the type II polyproline helix region, may be modified to render the region substantially cationic. As an example, one or more residues may be substituted with cationic amino acid residues such as arginine. The miniature proteins may also have additional functions, such …
Inverse Velocity Dependence Of Vibrationally Promoted Electron Emission From A Metal Surface, N. H. Nahler, J. D. White, Jerry L. Larue, Daniel J. Auerbach, Alec M. Wodtke
Inverse Velocity Dependence Of Vibrationally Promoted Electron Emission From A Metal Surface, N. H. Nahler, J. D. White, Jerry L. Larue, Daniel J. Auerbach, Alec M. Wodtke
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
All previous experimental and theoretical studies of molecular interactions at metal surfaces show that electronically nonadiabatic influences increase with molecular velocity. We report the observation of a nonadiabatic electronic effect that follows the opposite trend: The probability of electron emission from a low–work function surface—Au(111) capped by half a monolayer of Cs—increases as the velocity of the incident NO molecule decreases during collisions with highly vibrationally excited NO(X2π½, V = 18; V is the vibrational quantum number of NO), reaching 0.1 at the lowest velocity studied. We show that these results are consistent with a vibrational …
The Work Function Of Submonolayer Cesium-Covered Gold: A Photoelectron Spectroscopy Study, Jerry L. Larue, J. D. White, N. H. Nahler, Z. Liu, Y. Sun, P. A. Pianetta, Daniel J. Auerbach, Alec M. Wodtke
The Work Function Of Submonolayer Cesium-Covered Gold: A Photoelectron Spectroscopy Study, Jerry L. Larue, J. D. White, N. H. Nahler, Z. Liu, Y. Sun, P. A. Pianetta, Daniel J. Auerbach, Alec M. Wodtke
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Using visible and x-ray photoelectron spectroscopy, we measured the work function of a Au(111) surface at a well-defined submonolayer coverage of Cs. For a Cs coverage producing a photoemission maximum with a He–Ne laser, the work function is , consistent with previous assumptions used to analyze vibrationally promoted electron emission. A discussion of possible Cs layer structures is also presented.
Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis
Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis
Chemistry Faculty Publications
Chlorination and bromination reactions of thiazolo[5,4-d]thiazole led to the generation of its mono- and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4-d]thiazole ring system. X-ray analysis demonstrates that both 2-bromothiazolo[5,4-d]-thiazole and 2,5-dibromothiazolo[5,4-d]thiazole are planar structures, with strongly manifested π-stacking in the solid state. Theoretical analysis of the pyridine-catalyzed halogenation (MP2/6-31+G(d) and B3LYP/6-31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C-halogenation with N-halopyridine as electrophile; …