Chemistry Commons^™

Simpol.1: A Simple Group Contribution Method For Predicting Vapor Pressures And Enthalpies Of Vaporization Of Multifunctional Organic Compounds, James F. Pankow, William E. Asher

Physics Faculty Publications and Presentations

The SIMPOL.1 group contribution method is developed for predicting the liquid vapor pressure p^o_L (atm) and enthalpy of vaporization Δ H_vap (kJ mol^-1) of organic compounds as functions of temperature (T). For each compound i, the method assumes log₁₀p^o_L,i (T)=∑_kν_k,ib_k(T) where ν_k,i is the number of groups of type k, and b_k (T) is the contribution to log₁₀p^o_L,i (T) by each group of type k. A …

Iron(Iii)-Salophene: An Organometallic Compound With Selective Cytotoxic And Anti-Proliferative Properties In Platinum-Resistant Ovarian Cancer Cells, Thilo S. Lange, Kyu Kwang Kim, Rakesh K. Singh, Robert M. Strongin, Carolyn Mccourt, Laurent Brard

Chemistry Faculty Publications and Presentations

Background: In this pioneer study to the biological activity of organometallic compound Iron(III)-salophene (Fe-SP) the specific effects of Fe-SP on viability, morphology, proliferation, and cell-cycle progression on platinum-resistant ovariancancer cell lines were investigated.

Methodology/Principal Findings: Fe-SP displayed selective cytotoxicity against SKOV-3 and OVCAR-3 (ovarian epithelial adenocarcinoma) cell lines at concentrations between 100 nM and 1 μM, while the viability of HeLa cells (epithelial cervix adenocarcinoma) or primary lung or skin fibroblasts was not affected. SKOV-3 cells in contrast to fibroblasts after treatment with Fe-SP revealed apparent hallmarks of apoptosis including densely stained nuclear granular bodies within fragmented nuclei, highly condensed …

Towards The Rational Design Of Mri Contrast Agents: Electron Spin Relaxation Is Largely Unaffected By The Coordination Geometry Of Gadolinium(Iii)–Dota-Type Complexes, Alain Borel, Jonathan F. Bean, Robert B. Clarkson, Lothar Helm, Loïck Moriggi, A. Dean Sherry, Mark Woods

Chemistry Faculty Publications and Presentations

Electron‐spin relaxation is one of the determining factors in the efficacy of MRI contrast agents. Of all the parameters involved in determining relaxivity it remains the least well understood, particularly as it relates to the structure of the complex. One of the reasons for the poor understanding of electron‐spin relaxation is that it is closely related to the ligand‐field parameters of the Gd³⁺ ion that forms the basis of MRI contrast agents and these complexes generally exhibit a structural isomerism that inherently complicates the study of electron spin relaxation. We have recently shown that two DOTA‐type ligands could be …

Determination Of Enantiomeric Compositions Of Analytes Using Novel Fluorescent Chiral Molecular Micelles And Steady State Fluorescence Measurements, Alicia A. Williams, Sayo O. Fakayode, Onur Alptürk, Christina M. Jones, Mark Lowry, Robert M. Strongin, Isiah M. Warner

Chemistry Faculty Publications and Presentations

Novel fluorescent chiral molecular micelles (FCMMs) were synthesized, characterized, and employed as chiral selectors for enantiomeric recognition of non-fluorescent chiral molecules using steady state fluorescence spectroscopy. The sensitivity of the fluorescence technique allowed for investigation of low concentrations of chiral selector (3.0 x 10(-5) M) and analyte (5.0 x 10(-6) M) to be used in these studies. The chiral interactions of glucose, tartaric acid, and serine in the presence of FCMMs poly(sodium N-undecanoyl-L-tryptophanate) [poly-L-SUW], poly(sodium N-undecanoyl-L-tyrosinate) [poly-L-SUY], and poly(sodium N-undecanoyl-L-phenylalininate) [poly-SUF] were based on diastereomeric complex formation. Poly-L-SUW had a significant fluorescence emission spectral difference as compared to poly-L-SUY and …

Discrete Sums For The Rapid Determination Of Exponential Decay Constants, Michael A. Everest, Dean B. Atkinson

Chemistry Faculty Publications and Presentations

Several computational methods are presented for the rapid extraction of decay time constants from discrete exponential data. Two methods are found to be comparably fast and highly accurate. They are corrected successive integration and a method involving the Fourier transform (FT) of the data and the application of an expression that does not assume continuous data. FT methods in the literature are found to introduce significant systematic error owing to the assumption that data are continuous. Corrected successive integration methods in the literature are correct, but we offer a more direct way of applying them which we call linear regression …

Modulation Of Water Exchange In Europium(Iii) Dota–Tetraamide Complexes Via Electronic Substituent Effects, S. James Ratnakar, Mark Woods, Angelo J.M. Lubag, Zoltan Kovacs, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The chemical exchange saturation transfer (CEST) efficiency for a series Eu³⁺-based tetraamide complexes bearing p-substituents on a single coordinating pendant arm is highly sensitive to water exchange rates. The CEST effect increases in the order Me < MeO < F ∼ CO₂^tBu < CN ≪ H. These results show that CEST contrast can be modulated by changes in electron density at a single ligating atom, and this forms the basis of creating imaging agents that respond to chemical oxidation and reduction.

Chiral Recognition Of Amino Acids By Use Of A Fluorescent Resorcinarene, Gerald I. Richard, Hadi M. Marwani, Shan Jiang, Sayo O. Fakayode, Mark Lowry, Robert M. Strongin, Isiah M. Warner

Chemistry Faculty Publications and Presentations

The spectroscopic properties of a chiral boronic acid based resorcinarene macrocycle employed for chiral analysis were investigated. Specifically, the emission and excitation characteristics of tetraarylboronate resorcinarene macrocycle (TBRM) and its quantum yield were evaluated. The chiral selector TBRM was investigated as a chiral reagent for the enantiomeric discrimination of amino acids using steady-state fluorescence spectroscopy. Chiral recognition of amino acids in the presence of the macrocycle was based on diastereomeric complexes. Results demonstrated that TBRM had better chiral discrimination ability for lysine as compared to the other amino acids. Partial least squares regression modeling (PLS-1) of spectral data for macrocycle-lysine …

An Embarrassment Of Riches: The Enzymology Of Rna Modification, Dirk Iwata-Reuyl

Chemistry Faculty Publications and Presentations

The maturation of transfer RNA (tRNA) involves extensive chemical modification of the constituent nucleosides and results in the introduction of significant chemical diversity to tRNA. Many of the pathways to these modified nucleosides are characterized by chemically complex transformations, some of which are unprecedented in other areas of biology. To illustrate the scope of the field, recent progress in understanding the enzymology leading to the formation of two distinct classes of modified nucleosides, the thiouridines and queuosine, a 7-deazaguanosine, is reviewed. In particular, recent data validating the involvement of several proposed intermediates in the formation of thiouridines are discussed, including …

Unsymmetric Aryl–Alkyl Disulfide Growth Inhibitors Of Methicillin-Resistant Staphylococcus Aureus And Bacillus Anthracis, Edward Turos, Kevin D. Revell, Praveen Ramaraju, Danielle A. Gergeres, Kerriann Greenhalgh, Ashley Young, Nalini Sathyanarayan, Sonja Dickey, Daniel Lim, Mamoun M. Alhamadsheh, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

This study describes the antibacterial properties of synthetically-produced mixed aryl alkyl disulfide compounds as a means to control the growth of Staphylococcus aureus and Bacillus anthracis. Some of these compounds exerted strong in vitro bioactivity. Our results indicate that among the twelve different aryl substituents examined, nitrophenyl derivatives provide the strongest antibiotic activities. This may be the result of electronic activation of the arylthio moiety as a leaving group for nucleophilic attack on the disulfide bond. Small alkyl residues on the other sulfur provide the best activity as well, which for different bacteria appears to be somewhat dependent on …

Synthesis And Characterization Of Novel Chiral Ionic Liquids And Investigation Of Their Enantiomeric Recognition Properties, David K. Bwambok, Hadi M. Marwani, Vivian E. Fernand, Sayo O. Fakayode, Mark Lowry, Ioan Negulescu, Robert M. Strongin, Isiah M. Warner

Chemistry Faculty Publications and Presentations

We report the synthesis and characterization of amino acid ester based chiral ionic liquids, derived from L- and D-alanine tert butyl ester chloride. The synthesis was accomplished via an anion metathesis reaction between commercially available L- and D-alanine tert butyl ester chloride using a variety of counterions such as lithium bis (trifluoromethane) sulfonimide, silver nitrate, silver lactate, and silver tetrafluoroborate. Both enantiomeric forms were obtained as confirmed by bands of opposite sign in the circular dichroism spectra. The L- and D-alanine tert butyl ester bis (trifluoromethane) sulfonimide were obtained as liquids at room temperature and intriguingly exhibited the highest thermal …

Electrical Detection Of The Temperature Induced Melting Transition Of A Dna Hairpin Covalently Attached To Gold Interdigitated Microelectrodes, Greg P. Brewood, Yaswanth Rangineni, Daniel J. Fish, Ashwini Bhandiwad, David R. Evans, Raj Solanki, Albert S. Benight

Chemistry Faculty Publications and Presentations

The temperature induced melting transition of a self-complementary DNA strand covalently attached at the 5' end to the surface of a gold interdigitated microelectrode (GIME) was monitored in a novel, label-free, manner. The structural state of the hairpin was assessed by measuring four different electronic properties of the GIME (capacitance, impedance, dissipation factor and phase angle) as a function of temperature from 25 degrees C to 80 degrees C. Consistent changes in all four electronic properties of the GIME were observed over this temperature range, and attributed to the transition of the attached single-stranded DNA (ssDNA) from an intramolecular, folded …

The Cis-Δ2,3-Double Bond Of Phoslactomycins Is Generated By A Post-Pks Tailoring Enzyme, Nadaraj Palaniappan, Mamoun M. Alhamadsheh, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The antifungal phoslactomycins (PLM A-F), produced by Streptomyes sp HK803, are structurally unusual in that three of their four double bonds are in the cis form (Δ^12,13, Δ^14,15, Δ^2,3). The PLM polyketide synthase (PKS) has the predicted dehydratase catalytic domain in modules 1,2 and 5 required for establishing two of these cis double bonds (Δ^12,13Δ^14,15), as well as the only trans Δ^6,7double bond. By contrast, the formation of the cis Δ^2,3 in the unsaturated lactone moiety of PLMs has presented an enigma because the predicted dehydratase domain …

The Characterization Of Trna Modifying Enzymes S-Adenosylmethionine : Trna Ribosyltransferase-Isomerase (Quea) And A Novel Type I Gtp Cyclohydrolase, Shilah Amal Bonnett

Dissertations and Theses

Queuosine is a hypermodified nucleoside located in the wobble position of bacterial and eukaryotic tRNAs coding for Asp, Tyr, His and Asn. The biosynthesis involves the participation of S-adenosyl-methionine:tRNA ribosyltransferase-isomerase (QueA) and a GTP Cyclohydrolase-I. QueA catalyzes the transfer and isomerization of the ribosyl moiety from AdoMet to preQ1 modified tRNA. Substrate analogs of AdoMet were used to elucidate important substrate-enzyme interactions and to test key steps in the proposed chemical mechanism. Replacing AdoMet with SeAdoMet had little effect upon substrate binding but exhibited 30-fold reduction in kcat, consistent with deprotonation at C-5' as the first catalytic step. 7-deazaAdoMet failed …

Chemomechanical Polymers As Sensors And Actuators For Biological And Medicinal Applications, Hans-Jörg Schneider, Kazuaki Kato, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Changes in the chemical environment can trigger large motions in chemomechanical polymers. The unique feature of such intelligent materials, mostly in the form of hydrogels, is therefore, that they serve as sensors and actuators at the same time, and do not require any measuring devices, transducers or power supplies. Until recently the most often used of these materials responded to changes in pH. Chemists are now increasingly using supramolecular recognition sites in materials, which are covalently bound to the polymer backbone. This allows one to use a nearly unlimited variety of guest (or effector) compounds in the environment for a …

Potentiometric And Relaxometric Properties Of A Gadolinium-Based Mri Contrast Agent For Sensing Tissue Ph, Ferenc K. Kálmán, Mark Woods, Peter Caravan, Paul Jurek, Marga Spiller, Gyula Tircso, Róbert Király, Ernő Brücher, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The pH-sensitive contrast agent, GdDOTA-4AmP (Gd1) has been successfully used to map tissue pH by MRI. Further studies now demonstrate that two distinct chemical forms of the complex can be prepared depending upon the pH at which Gd³⁺ is mixed with ligand 1. The desired pH-sensitive form of this complex, referred to here as a Type II complex, is obtained as the exclusive product only when the complexation reaction is performed above pH 8. At lower pH values, a second complex is formed that, by analogy with an intermediate formed during the preparation of GdDOTA, we tentatively assign …

Albumin-Binding Paracest Agents, M. Meser Ali, Mark Woods, Eul Hyun Suh, Zoltan Kovacs, Gyula Tircsó, Piyu Zhao, Vikram D. Kodibagkar, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Lanthanide complexes (Eu³⁺, Gd³⁺ and Yb³⁺) of two different 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid tetraamide derivatives containing two (2) and four (3) O-benzyl-L-serine amide substituents were synthesized and their chemical exchange saturation transfer (CEST) and relaxometric properties were examined in the presence and absence of human serum albumin (HSA). Both Eu2 and Eu3 display a significant CEST effect from a single slowly exchanging Eu³⁺-bound water molecule, making these PARACEST complexes potentially useful as vascular MRI agents. Yb2 also showed a detectable CEST effect from both the Yb³⁺-bound water protons and the …

A Bridge To Coordination Isomer Selection In Lanthanide(Iii) Dota-Tetraamide Complexes, Jeff Vipond, Mark Woods, Piyu Zhao, Gyula Tircsó, Jimin Ren, Simon G. Bott, Doug Ogrin, Garry Kiefer, Zoltan Kovacs, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Interest in macrocyclic lanthanide complexes such as DOTA is driven largely through interest in their use as contrast agents for MRI. The lanthanide tetraamide derivatives of DOTA have shown considerable promise as PARACEST agents, taking advantage of the slow water exchange kinetics of this class of complex. We postulated that water exchange in these tetraamide complexes could be slowed even further by introducing a group to sterically encumber the space above the water coordination site, thereby hindering the departure and approach of water molecules to the complex. The ligand 8O₂-bridged-DOTAM was synthesized in a 34% yield from cyclen. …

The Structure And Function Of Small Nucleolar Ribonucleoproteins, Steve Reichow, Tomoko Hamma, Adrian R. Ferré-D’Amaré, Gabriele Varani

Chemistry Faculty Publications and Presentations

Eukaryotes and archaea use two sets of specialized ribonucleoproteins (RNPs) to carry out sequencespecific methylation and pseudouridylation of RNA, the two most abundant types of modifications of cellular RNAs. In eukaryotes, these protein–RNA complexes localize to the nucleolus and are called small nucleolar RNPs (snoRNPs), while in archaea they are known as small RNPs (sRNP). The C/D class of sno(s)RNPs carries out ribose- 20-O-methylation, while the H/ACA class is responsible for pseudouridylation of their RNA targets. Here, we review the recent advances in the structure, assembly and function of the conserved C/D and H/ACA sno(s)RNPs. Structures of each of the …

Dna Multiplex Hybridization On Microarrays And Thermodynamic Stability In Solution: A Direct Comparison, Daniel J. Fish, M. Todd Horne, Greg P. Brewood, Jim P. Goodarzi, Saba Alemayehu, Ashwini Bhandiwad, Robert P. Searles, Albert S. Benight

Chemistry Faculty Publications and Presentations

Hybridization intensities of 30 distinct short duplex DNAs measured on spotted microarrays, were directly compared with thermodynamic stabilities measured in solution. DNA sequences were designed to promote formation of perfect match, or hybrid duplexes containing tandem mismatches. Thermodynamic parameters DeltaH degrees , DeltaS degrees and DeltaG degrees of melting transitions in solution were evaluated directly using differential scanning calorimetry. Quantitative comparison with results from 63 multiplex microarray hybridization experiments provided a linear relationship for perfect match and most mismatch duplexes. Examination of outliers suggests that both duplex length and relative position of tandem mismatches could be important factors contributing to …

Modular Polyketide Synthases And Cis Double Bond Formation:  Establishment Of Activated Cis-3-Cyclohexylpropenoic Acid As The Diketide Intermediate In Phoslactomycin Biosynthesis, Mamoun M. Alhamadsheh, Nadaraj Palaniappan, Suparna Daschouduri, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The majority of modular polyketide synthase (PKS) systems which generate unsaturated products do so with trans double bonds. Phoslactomycin B (PLM B) presents a class of antitumor and antiviral natural polyketide products that have unique structural features, including a linear unsaturated backbone with one trans and three cis double bonds. There is substantial evidence that trans double bonds are established by ketoreductase-dehydratase (KR-DH) didomains within a PKS module. In cases where modules containing these didomains appear to generate product containing a cis double bond there is no experimental evidence to determine if they do so directly, or if they also …

Antibacterial Targets In Fatty Acid Biosynthesis, H. Tonie Wright, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The fatty acid biosynthesis pathway is an attractive but still largely unexploited target for development of new anti-bacterial agents. The extended use of the anti-tuberculosis drug isoniazid and the antiseptic triclosan, which are inhibitors of fatty acid biosynthesis, validates this pathway as a target for anti-bacterial development. Differences in subcellular organization of the bacterial and eukaryotic multi-enzyme fatty acid synthase systems offer the prospect of inhibitors with host vs. target specificity. Platensimycin, platencin, and phomallenic acids, newly discovered natural product inhibitors of the condensation steps in fatty acid biosynthesis, represent new classes of compounds with antibiotic potential. An almost complete …

Probing Reactivity And Substrate Specificity Of Both Subunits Of The Dimeric Mycobacterium Tuberculosis Fabh Using Alkyl-Coa Disulfide Inhibitors And Acyl-Coa Substrates, Sarbjot Sachdeva, Faik Musayev, Mamoun M. Alhamadsheh, J. Neel Scarsdale, H. Tonie Wright, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The dimeric Mycobacterium tuberculosis FabH (mtFabH) catalyses a Claisen-type condensation between an acyl-CoA and malonyl-acyl carrier protein (ACP) to initiate the Type II fatty acid synthase cycle. To analyze the initial covalent acylation of mtFabH with acyl-CoA, we challenged it with mixture of C6-C20 acyl-CoAs and the ESI-MS analysis showed reaction at both subunits and a strict specificity for C12 acyl CoA. Crystallographic and ESI-MS studies of mtFabH with a decyl-CoA disulfide inhibitor revealed a decyl chain bound in acyl-binding channels of both subunits through disulfide linkage to the active site cysteine. These data provide the first unequivocal evidence that …

Statistical Thermodynamics And Kinetics Of Dna Multiplex Hybridization Reactions, Albert S. Benight, M. T. Horne, D. J. Fish

Chemistry Faculty Publications and Presentations

A general analytical description of the equilibrium and reaction kinetics of DNA multiplex hybridization has been developed. In this approach, multiplex hybridization is considered to be a competitive multichannel reaction process: a system wherein many species can react both specifically and nonspecifically with one another. General equations are presented that can consider equilibrium and kinetic models of multiplex hybridization systems comprised, in principle, of any number of targets and probes. Numerical solutions to these systems for both equilibrium and kinetic behaviors are provided. Practical examples demonstrate clear differences between results obtained from more common simplex methods, in which individual hybridization …

Europium(Iii) Macrocyclic Complexes With Alcohol Pendant Groups As Chemical Exchange Saturation Transfer Agents, Mark Woods, Donald E. Woessner, Piyu Zhao, Azhar Pasha, Meng-Yin Yang, Ching-Hui Huang, Olga Vasalatiy, Janet R. Morrow, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Paramagnetic lanthanide(III) complexes that contain hyperfine-shifted exchangeable protons offer considerable advantages over diamagnetic molecules as chemical exchange saturation transfer (CEST) agents for MRI. As part of a program to investigate avenues to improve the sensitivity of such agents, the CEST characteristics of europium(III) macrocyclic complexes having appended hydroxyethyl groups were investigated. The CEST spectrum of the asymmetrical complex, EuCNPHC³⁺, shows five distinct peaks for each magnetically nonequivalent exchangeable proton in the molecule. The CEST spectra of this complex were fitted to NMR Bloch theory to yield exchange rates between each of six exchanging proton pools (five on the …

Comments On The Mechanism Of Aging Of Antimony Doped Tin Oxide Based Electrochromic Devices, Joo C. Chan, Nicole A. Hannah, Shankar B. Rananavare, Laura Yeager, Liviu Dinescu, Ashok Saraswat, Pradeep Iyer, James P. Coleman

Chemistry Faculty Publications and Presentations

Electrochromic effects of antimony doped tin oxide (ATO) nanoparticles are investigated to probe device yellowing (degradation). Voltage vs contrast ratio curves exhibit hysteresis, i.e., image-sticking phenomena due to irreversible charge insertion. X-ray, impedance and optical b* studies suggest that the yellowing/charge trapping is nanoparticle size-dependent with 4 nm size particles exhibiting the least yellowing. Yellowing results in increased impedances of electrode–electrolyte interface and electrode corrosion. Plausible sources of discoloration are formation of insulating complex alkali oxide film, carrier inversion (n-to-p type) through electrochemical Li doping, redeposition of the corroded electrode material and perhaps residual concentration of charge-transfer species.

Structural And Chiroptical Properties Of The Two Coordination Isomers Of Ybdota-Type Complexes, Lorenzo Di Bari, Gennaro Pescitelli, A. Dean Sherry, Mark Woods

Chemistry Faculty Publications and Presentations

Studies of the structural, physical, and chemical properties of the lanthanide(III) complexes of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and related ligands are often complicated by the presence of two coordination isomers in solution. Since these coordination isomers are in exchange and cannot be separated, many techniques offer information only on the weighted average of the two isomers. Lanthanide ion complexes formed with the ligands S(RRRR)NO₂BnDOTMA and S(SSSS)NO₂BnDOTMA preferentially adopt only one of the two common coordination isomers in solution, so the ytterbium complexes of these ligands offer a unique opportunity to study …

Effects Of Gramicidin-A On The Adsorption Of Phospholipids To The Air–Water Interface, Samares C. Biswas, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

Prior studies suggest that the hydrophobic surfactant proteins, SP-B and SP-C, promote adsorption of the lipids in pulmonary surfactant to an air–water interface by stabilizing a negatively curved rate-limiting structure that is intermediate between bilayer vesicles and the surface film. This model predicts that other peptides capable of stabilizing negative curvature should also promote lipid adsorption. Previous reports have shown that under appropriate conditions, gramicidin-A (GrA) induces dioleoyl phosphatidylcholine (DOPC), but not dimyristoyl phosphatidylcholine (DMPC), to form the negatively curved hexagonal-II (HII) phase. The studies reported here determined if GrA would produce the same effects on adsorption of DMPC and …

Towards The Rational Design Of Mri Contrast Agents: A Practical Approach To The Synthesis Of Gadolinium Complexes That Exhibit Optimal Water Exchange, Mark Woods, Mauro Botta, Stefano Avedano, Jing Wang, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The gadolinium(III) complex of S-SSSS-NO₂BnDOTMA exhibits water exchange kinetics that are optimal for use in high relaxivity or targeted contrast agents. However, the synthesis of this ligand is hampered by the steric encumbrance imparted upon the cyclen ring by the nitrobenzyl substituent. A relatively simple modification has been used to enable the synthesis of larger quantities of a bifunctional ligand that retains similar fast water exchange properties. The gadolinium complex of S-SSS-NO₂BnDO3MA-1A is shown to retain the rapid water exchange kinetics characteristic of a twisted square antiprismatic (TSAP) …

The Reno Aerosol Optics Study: An Evaluation Of Aerosol Absorption Measurement Methods, Patrick J. Sheridan, W. Patrick Arnott, John A. Ogren, Elisabeth Andrews, Dean B. Atkinson, David S. Covert, Hans Moosmüller, Andreas Petzold, Beat Schmid, Anthony W. Strawa, Ravi Varma, Aki Virkkula

Chemistry Faculty Publications and Presentations

The Reno Aerosol Optics Study (RAOS) was designed and conducted to compare the performance of many existing and new instruments for the in situ measurement of aerosol optical properties with a focus on the determination of aerosol light absorption. For this study, simple test aerosols of black and white particles were generated and combined in external mixtures under low relative humidity conditions and delivered to each measurement system. The aerosol mixing and delivery system was constantly monitored using particle counters and nephelometers to ensure that the same aerosol number concentration and amount reached the different instruments. The aerosol light-scattering measurements …

The Subsystems Approach To Genome Annotation And Its Use In The Project To Annotate 1000 Genomes, Ross Overbeek, Tadhg Begley, Ralph M. Butler, Jomuna V. Choudhuri, Han-Yu Chuang, Matthew Cohoon, Valérie De Crécy-Lagard, Naryttza Diaz, Terry Disz, Robert Edwards, Michael Fonstein, Ed D. Frank, Svetlana Gerdes, Elizabeth M. Glass, Alexander Goesmann, Andrew Hanson, Dirk Iwata-Reuyl, Roy Jensen, Neema Jamshidi, Lutz Krause, Michael Kubal, Niels Larsen, Burkhard Linke, Alice C. Mchardy, Folker Meyer, Heiko Neuweger, Gary Olsen, Robert Olson, Andrei Osterman, Vasiliy Portnoy, Gordon D. Pusch, Dmitry A. Rodionov, Christian Rückert, Jason Steiner, Rick Stevens, Ines Thiele, Olga Vassieva, Yuzhen Ye, Olga Zagnitko, Veronika Vonstein

Chemistry Faculty Publications and Presentations

The release of the 1000^th complete microbial genome will occur in the next two to three years. In anticipation of this milestone, the Fellowship for Interpretation of Genomes (FIG) launched the Project to Annotate 1000 Genomes. The project is built around the principle that the key to improved accuracy in high through put annotation technology is to have experts annotate single subsystems over the complete collection of genomes, rather than having an annotation expert attempt to annotate all of the genes in a single genome. Using the subsystems approach, all of the genes implementing the subsystem are analyzed by …