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25,466 full-text articles. Page 661 of 682.

Recognition Mediated Encapsulation And Isolation Of Flavin-Polymer Conjugates Using Dendritic Guest Moieties, C Subramani, G Yesilbag, BJ Jordan, XN Li, A Khorasani, G Cooke, A Sanyal, VM Rotello 2010 University of Massachusetts - Amherst

Recognition Mediated Encapsulation And Isolation Of Flavin-Polymer Conjugates Using Dendritic Guest Moieties, C Subramani, G Yesilbag, Bj Jordan, Xn Li, A Khorasani, G Cooke, A Sanyal, Vm Rotello

Vincent Rotello

Diaminopyridine dendritic scaffolds encapsulate polymeric flavin via non-covalent interactions and demonstrate isolation of the redox moiety.


Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, MH Park, XX Duan, Y Ofir, B Creran, D Patra, XY Ling, J Huskens, VM Rotello 2010 University of Massachusetts - Amherst

Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, Mh Park, Xx Duan, Y Ofir, B Creran, D Patra, Xy Ling, J Huskens, Vm Rotello

Vincent Rotello

Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.


Water-Soluble Soa From Alkene Ozonolysis: Composition And Droplet Activation Kinetics Inferences From Analysis Of Ccn Activity, A. Asa-Awuku, A. Nenes, Song Gao, R. C. Flagan, John H. Seinfeld 2010 Georgia Institute of Technology

Water-Soluble Soa From Alkene Ozonolysis: Composition And Droplet Activation Kinetics Inferences From Analysis Of Ccn Activity, A. Asa-Awuku, A. Nenes, Song Gao, R. C. Flagan, John H. Seinfeld

Chemistry and Physics Faculty Articles

Cloud formation characteristics of the water-soluble organic fraction (WSOC) of secondary organic aerosol (SOA) formed from the ozonolysis of alkene hydrocarbons (terpinolene, 1-methlycycloheptene and cycloheptene) are studied. Based on size-resolved measurements of CCN activity (of the pure and salted WSOC samples) we estimate the average molar volume and surface tension depression associated with the WSOC using Köhler Theory Analysis (KTA). Consistent with known speciation, the results suggest that the WSOC are composed of low molecular weight species, with an effective molar mass below 200 g mol−1. The water-soluble carbon is also surface-active, depressing surface tension 10–15% from that ...


Thermal Degradation Of High-Temperature Fluorinated Polyimide And Its Carbon Fiber Composite, Andrea D. Adamczak, Adam A. Spriggs, Danielle M. Fitch, Walid Awad, Charles A. Wilkie, Jaime C. Grunlan 2010 Texas A & M University - College Station

Thermal Degradation Of High-Temperature Fluorinated Polyimide And Its Carbon Fiber Composite, Andrea D. Adamczak, Adam A. Spriggs, Danielle M. Fitch, Walid Awad, Charles A. Wilkie, Jaime C. Grunlan

Chemistry Faculty Research and Publications

No abstract provided.


Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson 2010 Virginia Polytechnic Institute and State University

Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy and the quartz crystal microbalance measurements are used to examine the ability of potential applied to a substrate to create, in situ, conditions favorable for the electrostatic deposition of polyelectrolytes onto a gold substrate modified by the self-assembly of cysteine. Cysteine is a zwitterionic compound that, when confined to a substrate, has the ability to establish either a net positive or a net negative interfacial charge, depending on the conditions. As such, cysteine modified interfaces could possibly be used as a versatile substrate for deposition of either cationic or anionic polyelectrolytes. The potential of zero charge of ...


Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel 2010 John Carroll University

Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel

Paul R. Challen

No abstract provided.


The Power Of The Weak: Recognition Of Ion Pairs In Water Using A Simple Array Sensor, Yuan-li Liu, Manuel A. Palacios, Pavel Anzenbacher 2010 Bowling Green State University

The Power Of The Weak: Recognition Of Ion Pairs In Water Using A Simple Array Sensor, Yuan-Li Liu, Manuel A. Palacios, Pavel Anzenbacher

Pavel Anzenbacher

An array sensor comprising six off-the-shelf indicators doped in a poly(ether-urethane) recognizes five cations, seven anions and thirty-five ion pairs at pH 5-9 in water. Such a discrimination capacity and recognition efficiency (6:35) with >= 93% accuracy is rare. Low cost and wide availability of various polymers and indicators could make this approach useful in numerous applications.


Open Notebook Science Challenge Solubilities Of Organic Compounds In Organic Solvents, Andrew Lang, Jean-Claude Bradley, Cameron Neylon, Rajarshi Guha, Antony J. Williams, Bill Hooker, Brent Friesen 2010 Drexel University

Open Notebook Science Challenge Solubilities Of Organic Compounds In Organic Solvents, Andrew Lang, Jean-Claude Bradley, Cameron Neylon, Rajarshi Guha, Antony J. Williams, Bill Hooker, Brent Friesen

College of Science and Engineering Faculty Research and Scholarship

The Open Notebook Science Solubility Challenge Solubility is an important consideration for many chemistry applications. Synthetic chemists usually use a solvent to perform reactions and knowledge of the solubility of the starting materials or products can be very useful to pick an appropriate solvent. Analytical chemists can use solubility to design separation techniques and factor in dynamic range considerations. Physical chemists can create and evaluate their models of how molecules interact in the solubilization and precipitation processes. Solubility data can be obtained from a variety of online and offline sources. As with all chemical data, it can be a challenge ...


Dual-Action Hygienic Coatings: Benefits Of Hydrophobicity And Silver Ion Release And Surface Analysis, Niall Stobie, Brendan Duffy, John Colreavy, Patrick McHale, Steven Hinder, Declan McCormack 2010 Technological University Dublin

Dual-Action Hygienic Coatings: Benefits Of Hydrophobicity And Silver Ion Release And Surface Analysis, Niall Stobie, Brendan Duffy, John Colreavy, Patrick Mchale, Steven Hinder, Declan Mccormack

Articles

Coatings that demonstrate reduced attachment of crystalline precipitates and the medical device colonising Staphylococcus epidermidis were prepared by the immobilisation of silver doped perfluoropolyether–urethane siloxane thin films on glass substrates. The presence of stratified hydrophobic perfluoropolyether groups protects the coating surface from the attachment of crystalline hydrophilic species such as chlorides and phosphates, whilst silver ion release inhibited attachment of S. epidermidis and subsequent biofilm formation in vitro. The release of silver ions protects the perfluoro groups from the hydrophobic interactions of S. epidermidis cells, which can reduce the hydrophobicity of the protective coating. These coatings also exhibited significant ...


An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos 2010 University of Missouri–St. Louis

An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos

James Chickos

No abstract provided.


Hyperbranched Conjugated Polymers: Postfunctionalization, C Kub, J Tolosa, AJ Zucchero, PL McGrier, C Subramani, A Khorasani, VM Rotello, UHF Bunz 2010 University of Massachusetts - Amherst

Hyperbranched Conjugated Polymers: Postfunctionalization, C Kub, J Tolosa, Aj Zucchero, Pl Mcgrier, C Subramani, A Khorasani, Vm Rotello, Uhf Bunz

Vincent Rotello

Out on a limb: Sonogashira coupling of a suitable AB(2) monomer containing two iodine and one alkyne group forms a hyperbranched conjugated polymer that is studded with iodine end groups (see picture: I purple). These iodine groups are a perfect handle for convenient, efficient, and high-yielding post-functionalization to access hyperbranched, fluorescent poly(phenyleneethynylene)s.


Methods And Kit For Determination Of Prostacyclin In Plasma, Sylvia Daunert, Michael Poon, Urvee Desai, Sapna K. Deo 2010 University of Kentucky

Methods And Kit For Determination Of Prostacyclin In Plasma, Sylvia Daunert, Michael Poon, Urvee Desai, Sapna K. Deo

Chemistry Faculty Patents

A solid-phase immunoassay for 6-keto-Prostaglandin F, the stable hydrolysis product of prostacyclin (Prostaglandin I2) is disclosed. Prostacyclin, a potent vasodilator with anti-platelet and anti-proliferative properties is an effective treatment for primary pulmonary hypertension and pulmonary arterial hypertension associated with scleroderma and scleroderma-like syndrome. Levels of 6-keto-Prostaglandin F can be directly correlated with levels of prostacyclin. Therefore, 6-keto-Prostaglandin F has become the indicator of choice to measure prostacyclin levels. The single step immunoassay for 6-keto-Prostaglandin F uses the bioluminescent protein, aequorin as a label. Analyte-label conjugates were constructed by linking the carboxyl group of 6-keto-Prostaglandin F ...


Excited-State Intramolecular Hydrogen Atom Transfer Of Curcumin In Surfactant Micelles, Ramkrishna Adhikary, Philip J. Carlson, Tak W. Lee, Jacob W. Petrich 2010 Iowa State University

Excited-State Intramolecular Hydrogen Atom Transfer Of Curcumin In Surfactant Micelles, Ramkrishna Adhikary, Philip J. Carlson, Tak W. Lee, Jacob W. Petrich

Chemistry Publications

Femtosecond fluorescence upconversion experiments were performed on the naturally occurring medicinal pigment, curcumin, in anionic, cationic, and neutral micelles. In our studies, the micelles are composed of sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and triton X-100 (TX-100). We demonstrate that the excited-state kinetics of curcumin in micelles have a fast (3−8 ps) and slow (50−80 ps) component. While deuteration of curcumin has a negligible effect on the fast component, the slow component exhibits a pronounced isotope effect of ∼1.6, indicating that micelle-captured curcumin undergoes excited-state intramolecular hydrogen atom transfer. Studies of solvation dynamics of ...


Mesoporous Silica Microparticles Enhance The Cytotoxicity Of Anticancer Platinum Drugs, Zhimin Tao, Bonnie Toms, Jerry Goodisman, Tewodros Asefa 2010 Syracuse University

Mesoporous Silica Microparticles Enhance The Cytotoxicity Of Anticancer Platinum Drugs, Zhimin Tao, Bonnie Toms, Jerry Goodisman, Tewodros Asefa

Chemistry - Faculty Scholarship

We report on the endocytosis and the time-dependent enhanced cytotoxicity of anticancer platinum drugs when the drugs are combined with (or loaded into) one of the two most common types of mesoporous silica materials, MCM-41 or SBA-15. The anticancer drug cisplatin and its isomer transplatin, when loaded on MCM-41 and SBA-15 microparticles, were less cytotoxic to leukemia cells than the drugs alone after 12 h exposure. However, the drug-loaded microparticles exhibited unprecedented enhanced cytotoxicity to the cancerous cells after 24 h of exposure. This cytotoxicity of the drug-loaded microparticles was even higher than of the pure drugs in solutions, suggesting ...


Intracellular Delivery Of A Membrane-Impermeable Enzyme In Active Form Using Functionalized Gold Nanoparticles, P Ghosh, XC Yang, R Arvizo, ZJ Zhu, SS Agasti, ZH Mo, VM Rotello 2010 University of Massachusetts - Amherst

Intracellular Delivery Of A Membrane-Impermeable Enzyme In Active Form Using Functionalized Gold Nanoparticles, P Ghosh, Xc Yang, R Arvizo, Zj Zhu, Ss Agasti, Zh Mo, Vm Rotello

Vincent Rotello

Gold nanoparticles were coated with a short peptide to promote intracellular delivery of membrane-impermeable proteins. Through microscopy and enzyme assays, we demonstrated the particles were able to transport functional enzymes into a variety of cell lines. Significantly, the transported proteins were able to escape from endosomes. Moreover, these particles showed no apparent cytotoxicity.


The Heat Capacity And Thermodynamic Properties Of The Iron Oxides And Their Relation To The Mineral Core Of The Iron Storage Protein Ferritin, Claine Lindsey Morton Snow 2010 Brigham Young University - Provo

The Heat Capacity And Thermodynamic Properties Of The Iron Oxides And Their Relation To The Mineral Core Of The Iron Storage Protein Ferritin, Claine Lindsey Morton Snow

Theses and Dissertations

The iron oxides are a group of materials with geological, biological, and technological importance. A thermodynamic understanding of these materials is important because it provides information about their relative stabilities, chemical reactivity, and transformations. This study provides the heat capacity of a nanocrystalline magnetite (Fe3O4) sample, bulk hematite (α-Fe2O3), nanocrystalline hematite, akaganéite (β-FeOOH), and lepidocrocite (γ-FeOOH) at temperatures as low as 0.5 K. These measurements were fit to theoretical functions at temperatures lower than 15 K, and the respective thermophysical properties of these materials are discussed. Also the molar entropies of bulk hematite and hydrous nanocrystalline hematite as well ...


The Construction And Optimization On An Ion Mobility Spectrometer For The Analysis Of Explosives And Drugs, Hanh Tuyet Lai 2010 Florida International University

The Construction And Optimization On An Ion Mobility Spectrometer For The Analysis Of Explosives And Drugs, Hanh Tuyet Lai

FIU Electronic Theses and Dissertations

Today, over 15,000 Ion Mobility Spectrometry (IMS) analyzers are employed at worldwide security checkpoints to detect explosives and illicit drugs. Current portal IMS instruments and other electronic nose technologies detect explosives and drugs by analyzing samples containing the headspace air and loose particles residing on a surface. Canines can outperform these systems at sampling and detecting the low vapor pressure explosives and drugs, such as RDX, PETN, cocaine, and MDMA, because these biological detectors target the volatile signature compounds available in the headspace rather than the non-volatile parent compounds of explosives and drugs. In this dissertation research volatile signature ...


Proton Disorder And The Dielectric Constant Of Type Ii Clathrate Hydrates, Steven W. Rick 2010 University of New Orleans

Proton Disorder And The Dielectric Constant Of Type Ii Clathrate Hydrates, Steven W. Rick

Chemistry Faculty Publications

Computational studies are presented examining the degree of proton disorder in argon and molecular hydrogen sII clathrate hydrates. Results are presented using a variety of model potentials for the dielectric constant, the proton order parameter, and the molecular volume for the clathrate systems. The dielectric constant for the clathrate systems is found to be lower than the dielectric constant of ice in all models. The ratio of the clathrate to ice dielectric constant correlates well with the ratio of the densities, which is not the case for comparisons to the liquid, so that differences in the dielectric constants between ice ...


Investigation Of Deactivation Of Transition Metal Oxide Catalysts Supported On Γ-Al2o3 During Catalytic Oxidation Of Some Oxygen Containing Vocs In A Tubular Reactor, Hosein Afshary 2010 University of Tabriz

Investigation Of Deactivation Of Transition Metal Oxide Catalysts Supported On Γ-Al2o3 During Catalytic Oxidation Of Some Oxygen Containing Vocs In A Tubular Reactor, Hosein Afshary

Hosein Afshary

It is necessary to decrease the emission of Volatile organic compound ( VOCs ) to air and among of all destructive techniques used for decreasing these compounds, Catalytic Oxidation is considered a suitable technique but deactivation of catalysts through catalytic processes is one of the major problems and most be studied. In this Project, at First, gamma alumina supported metal oxide catalysts were made and also industrial Pt catalyst was prepared. Then structure of these catalysts was studied using XRD, SEM and FT-IR techniques. These techniques approved the nanostructure of catalysts. The amount of supported metals in each catalyst was determined by ...


A Natural Missing Link Between Activated And Downhill Protein Folding Scenarios, Feng Liu, Caroline Maynard, Gregory E. Scott, Artem Melnykov, Kathleen B. Hall, Martin Gruebele 2010 University of Illinois at Urbana-Champaign

A Natural Missing Link Between Activated And Downhill Protein Folding Scenarios, Feng Liu, Caroline Maynard, Gregory E. Scott, Artem Melnykov, Kathleen B. Hall, Martin Gruebele

Chemistry and Biochemistry

We propose protein PTB1:4W as a good candidate for engineering into a downhill folder. PTB1:4W has a probe-dependent thermal unfolding curve and sub-millisecond T-jump relaxation kinetics on more than one time scale. Its refolding rate in denaturant is a non-linear function of denaturant concentration (curved chevron plot). Yet at high denaturant concentration its unfolding is probe-independent, and the folding kinetics can be fitted to a single exponential decay. The domain appears to fold via a mechanism between downhill folding and activated folding over several small barriers, and when denaturant is added, one of these barriers greatly increases and ...


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