Physical Sciences and Mathematics | Open Access Articles

Multi-Species On-Road Remote Sensing Of Vehicle Emissions In Van Nuys, California – August 2010, Gary A. Bishop, Brent G. Schuchmann, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Azlactone-Functionalized Polymers As Reactive Templates For Parallel Polymer Synthesis: Synthesis And Screening Of A Small Library Of Cationic Polymers In The Context Of Dna Delivery, Bin Sun, Xianghui Liu, Maren E. Buck, David M. Lynn

Chemistry: Faculty Publications

Azlactone-functionalized polymers are used as reactive templates for the synthesis of a library of amine-functionalized polymers of interest in the context of DNA delivery and other applications.

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On-Road Emission Measurements Of Reactive Nitrogen Compounds From Three California Cities, Gary A. Bishop, Allison Peddle, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

The three California cities of San Jose, Fresno and West Los Angeles (wLA) were visited during March 2008 to collect on-road emission measurements of reactive nitrogen compounds from light-duty vehicles. At the San Jose and wLA sites comparison with historical measurements showed that emissions of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO) continue to decrease in the on-road fleet yet the ratio of nitrogen dioxide (NO₂) to NO in new diesel vehicles appears to be under going large increases. A small fleet of 2007 diesel ambulances measured in Fresno was found to have more than 60% …

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Ribosome Recycling Step In Yeast Cytoplasmic Protein Synthesis Is Catalyzed By Eef3 And Atp, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

After each round of protein biosynthesis, the posttermination complex (PoTC) consisting of a ribosome, mRNA, and tRNA must be disassembled into its components for a newround of translation. Here, we show that a Saccharomyces cerevisiae model PoTC was disassembled by ATP and eukaryotic elongation factor 3 (eEF3). GTP or ITP functioned with less efficiency and adenosine 5γ′-(β,γ-imido)triphosphate did not function at all. The kcat of eEF3 was 1.12 min-1, which is comparable to that of the in vitro initiation step. The disassembly reaction was inhibited by aminoglycosides and cycloheximide. The subunits formed from the yeast model PoTC remained separated under …

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The 5'-7-Methylguanosine Cap On Eukaryotic Mrnas Serves Both To Stimulate Canonical Translation Initiation And To Block An Alternative Pathway, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

Translational control is frequently exerted at the stage of mRNA recruitment to the initiating ribosome. We have reconstituted mRNA recruitment to the 43S preinitiation complex (PIC) using purified S. cerevisiae components. We show that eIF3 and the eIF4 factors not only stabilize binding of mRNA to the PIC, they also dramatically increase the rate of recruitment. Although capped mRNAs require eIF3 and the eIF4 factors for efficient recruitment to the PIC, uncapped mRNAs can be recruited in the presence of eIF3 alone. The cap strongly inhibits this alternative recruitment pathway, imposing a requirement for the eIF4 factors for rapid and …

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Observations Of Elevated Formaldehyde Over A Forest Canopy Suggest Missing Sources From Rapid Oxidation Of Arboreal Hydrocarbons, Nicole Bouvier-Brown

Chemistry and Biochemistry Faculty Works

To better understand the processing of biogenic VOCs (BVOCs) in the pine forests of the US Sierra Nevada, we measured HCHO at Blodgett Research Station using Quantum Cascade Laser Spectroscopy (QCLS) during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) of late summer 2007. Four days of the experiment exhibited particularly copious HCHO, with midday peaks between 15–20 ppbv, while the other days developed delayed maxima between 8–14 ppbv in the early evening. From the expansive photochemical data set, we attempt to explain the observed HCHO concentrations by quantifying the various known photochemical production and loss terms in its …

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What Is Wrong With Water Barometers?, Dan Sullivan, Robert W. Smith, E. J. Kemnitz, Kevin Barton, Robert M. Graham, Raymond A. Guenther, Larry Webber

Chemistry Faculty Publications

Every student who studies atmospheric pressure in physics or chemistry learns the principles behind the construction of barometers. Cistern barometers, such as those found in most laboratories, consist of a long glass tube containing an inverted column of liquid having an open end in a cistern of the liquid. Students learn that the column of liquid is supported by air pressure and is equal in weight to a column of air of the same diameter.

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The Efficacy Of Chemistry Outreach Programs On Middle School Students, Erica M. Dumeyer

Mahurin Honors College Capstone Experience/Thesis Projects

The current project was designed to determine if science outreach programs affect the attitude of the students toward science and increase the science content knowledge of the students participating in the program. Students from middle schools surrounding the Bowling Green area participated in the project. The data set includes a total of 850 students from 7th and 8th grade. Students were given a pre-test (taken several days before the presentation) and a post-test (taken several days after the presentation). The tests contain both subjective, affective as well as objective, content questions. The individual student pre-/post-tests were index numbered to protect …

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Dna Linking Number Change Induced By Sequence-Specific Dna-Binding Proteins, Bo Chen, Yazhong Xiao, Chang Liu, Chen-Zhong Li, Fenfei Leng

Department of Chemistry and Biochemistry

Sequence-specific DNA-binding proteins play a key role in many fundamental biological processes, such as transcription, DNA replication and recombination. Very often, these DNA-binding proteins introduce structural changes to the target DNA-binding sites including DNA bending, twisting or untwisting and wrapping, which in many cases induce a linking number change (ΔLk) to the DNA-binding site. Due to the lack of a feasible approach, ΔLk induced by sequence-specific DNA-binding proteins has not been fully explored. In this paper we successfully constructed a series of DNA plasmids that carry many tandem copies of a DNA-binding site for one sequence-specific DNA-binding …

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Immobilization Of The Aminopeptidase From Aeromonas Proteolytica On Mg2+/Al3+ Layered Double Hydroxide Particles, Steven T. Frey, Stephanie L. Guilmet, Richard G. Egan Iii, Alyssa Bennett, Sarah R. Soltau, Richard C. Holz

Chemistry Faculty Research and Publications

A novel biomaterial formed by the immobilization of the Aminopeptidase from Aeromonas proteolytica (AAP) on synthetic Mg²⁺ and Al³⁺ ion-containing layered double hydroxide (LDH) particles was prepared. Immobilization of AAP on the LDH particles in a buffered, aqueous mixture is rapid such that the maximum loading capacity, 1 × 10⁻⁹ moles of AAP/mg LDH, is achieved in a few minutes. X-ray powder diffraction of LDH samples before and after treatment with AAP indicates that the enzyme does not intercalate between the layers of LDH, but instead binds to the surface. Treatment of AAP/LDH with various amounts of …

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Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, Dorjderem Nyamjav, Sergey Rozhok, Richard C. Holz

Chemistry Faculty Research and Publications

A strategy to bind bacterial cells to surfaces in a directed fashion via dip-pen nanolithography (DPN) is presented. Cellular attachment to pre-designed DPN generated microarrays was found to be dependent on the shape and size of the surface feature. While this observation is likely due in part to a dense, well formed mercaptohexadecanoic acid (MHA) monolayer generated via DPN, it may also simply be due to the physical shape of the surface structure. Motile Pseudomonas aeruginosa bacterial cells were observed to bind to DPN generated mercaptohexadecanoic acid/poly-L-lysine (MHA/PLL) line patterns, 'blocks' made up of eight lines with 100 nm spacings, …

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A Shortened Synthesis Of Optically Pure Tricarbonyl[Methyl (2e,4e)-6-Oxo-2,4-Hexadienoate]Iron Leading To Improved Yield, Rajesh K. Pandey, Sergey Lindeman, William Donaldson

Chemistry Faculty Research and Publications

The (+)- and (–)-enantiomers of tricarbonyl[methyl (2E,4E)-6-oxo-2,4-hexadienoate]iron are prepared in 4 steps from commercially available hexadienal (26% and 25% yields, respectively).

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Infrared Spectroelectrochemical Reduction Of Iron Porphyrin Complexes, Zhongcheng Wei, Michael D. Ryan

Chemistry Faculty Research and Publications

The spectroelectrochemistry of iron porphinones and their nitrosyl complexes were examined by infrared spectroscopy, as well as ferrous octaethylporphyrin nitrosyl. With the use of d₈-THF, the solvent was transparent down to 1200 cm⁻¹. For the porphinones, the reduction of the macrocycle ring could be observed by the changes in the ν_CO band and, for the nitrosyl complex, the changes in the nitrosyl ligand were directly observable from the ν_NO band. Formation of the ferrous complexes led to a small downshift in the ν_CO band. Further reduction to the formal Fe(“I”) complex led to …

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Thermal Degradation Studies On Pmma–Het Acid Based Oligoesters Blends, Thangamani Rajkumar, Chinnaswamy Thangavel Vijayakumar, Palanichamy Sivasamy, Bojja Sreedhar, Charles A. Wilkie

Chemistry Faculty Research and Publications

Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented. The main volatile degradation products identified are CO, HCl, CO₂, H₂O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is also presented.

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Sulfur K-Edge Photo-Fragmentation Of Ethylene Sulfide, Wayne C. Stolte, Gunnar Ohrwall

Chemistry and Biochemistry Faculty Research

We have investigated the photofragmentation properties of the three-membered ring heterocyclic molecule ethylene sulfide or thiirane, C₂H₄S, by time-of-flight mass spectroscopy. Positive ions have been collected as a function of photon energy around the S K ionization threshold. Branching ratios were derived for all detected ions, which are informative of the decay dynamics and photofragmentation patterns of the core-excited species. We present a new assignment of the spectral features around the S K-edge.

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An Improved Synthesis Of A Ring-C Precursor To Cobyric Acid, Hui Wang, Peter A. Jacobi

Dartmouth Scholarship

Alkyne acid 10 was prepared in enantioselective fashion from allylic ester derivative (R)-18 via an E-selective Ireland-Claisen rearrangement followed by Si-assisted elimination of HBr. The present route offers significant advantages in terms of both scalability and overall yield compared to that previously described. Alkyne acid 10 is an attractive ring-C precursor for an ongoing synthesis of cobyric acid.

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Correlation Of The Real-Time Particulate Matter Emissions Measurements Of A Esp Remote Sensing Device (Rsd) And A Dekati Electronic Tailpipe Sensor (Etaps) With Gravimetrically Measured Pm From A Total Exhaust Dilution Tunnel System, Mridul Gautam, Donald H. Stedman, Daniel K. Carder, Benjamin Shade, Nigel Clark, Gregory Thompson, Scott Wayne, Gary A. Bishop, Brent G. Schuchmann, Dan Pope, Niranjan Vescio, Gary Full, Peter Mcclintock, Drew Rau

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Transition-Metal Ion Exchange Using Poly(Ethylene Glycol) Oligomers As Solvents, Gina M. Canfield, Michael Bizimis, Susan E. Latturner

Faculty Publications

Poly(ethylene glycol) oligomers have been found to be effective as alternative solvents for the ion exchange of Mn2þ , Fe2 þ , and Co2þ into hydrated and dehydrated Zeolite X (Na80Al80Si112- O384 3 nH2O). When attempted in aqueous solutions, the exchange of these cations quickly leads to destruction of the zeolite structure within 1-2 exchange cycles. However, in PEG oligomer solvents, the structure can be maintained and exchanges of 48% (Co2þ ), 80% (Mn2þ ), and 91% (Fe2þ ) are observed after one cycle under hydrated conditions. When rigorous steps are taken to remove all water from the zeolite before …

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Enantioselective Synthesis Of Bicarbocyclic Structures With An All-Carbon Quaternary Stereocenter Through Sequential Cross Metathesis And Intramolecular Rauhut-Currier Reaction, Yuan Qiao, Sanjeev Kumar, William Paul Malachowski

Chemistry Faculty Research and Scholarship

A new extension of the Birch-Cope sequence is described which allows the efficient enantioselective construction of highly functionalized, fused bicarbocyclic structures with an all-carbon quaternary stereo-center in two steps. The two-step sequence includes a cross metathesis between a terminal alkene and a polarized alkene followed by an intramolecular Rauhut-Currier reaction with a trialkylphosphine catalyst.

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Noninnocent Dithiolene Ligands: A New Oxomolybdenum Complex Possessing A Donor-Acceptor Dithiolene Ligand, Kelly G. Matz, Regina P. Mtei, Belinda Leung, Sharon J. Nieter Burgmayer, Martin L. Kirk

Chemistry Faculty Research and Scholarship

No abstract provided.

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Polystyrene-Supported Aluminum Chloride As An Efficient And Reusable Catalyst For Condensation Of Indole With Various Carbonyl Compounds, Bahman Tamami, Amir Nasrolahi Shirazi, Kaveh Parvanak Borujeni

Pharmacy Faculty Articles and Research

Crosslinked polystyrene-supported aluminum chloride (PS-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford diindolylmethanes. In addition, PS-AlCl3 shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, PS-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling …

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Major Challenges For The Modern Chemistry In Particular And Science In General, Vuk Uskoković

Pharmacy Faculty Articles and Research

In the past few hundred years, science has exerted an enormous influence on the way the world appears to human observers. Despite phenomenal accomplishments of science, science nowadays faces numerous challenges that threaten its continued success. As scientific inventions become embedded within human societies, the challenges are further multiplied. In this critical review, some of the critical challenges for the field of modern chemistry are discussed, including: (a) interlinking theoretical knowledge and experimental approaches; (b) implementing the principles of sustainability at the roots of the chemical design; (c) defining science from a philosophical perspective that acknowledges both pragmatic and realistic …

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Full-Text Articles in Physical Sciences and Mathematics

Multi-Species On-Road Remote Sensing Of Vehicle Emissions In Van Nuys, California – August 2010, Gary A. Bishop, Brent G. Schuchmann, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Azlactone-Functionalized Polymers As Reactive Templates For Parallel Polymer Synthesis: Synthesis And Screening Of A Small Library Of Cationic Polymers In The Context Of Dna Delivery, Bin Sun, Xianghui Liu, Maren E. Buck, David M. Lynn

Chemistry: Faculty Publications

On-Road Emission Measurements Of Reactive Nitrogen Compounds From Three California Cities, Gary A. Bishop, Allison Peddle, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Ribosome Recycling Step In Yeast Cytoplasmic Protein Synthesis Is Catalyzed By Eef3 And Atp, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

The 5'-7-Methylguanosine Cap On Eukaryotic Mrnas Serves Both To Stimulate Canonical Translation Initiation And To Block An Alternative Pathway, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

Observations Of Elevated Formaldehyde Over A Forest Canopy Suggest Missing Sources From Rapid Oxidation Of Arboreal Hydrocarbons, Nicole Bouvier-Brown

Chemistry and Biochemistry Faculty Works

What Is Wrong With Water Barometers?, Dan Sullivan, Robert W. Smith, E. J. Kemnitz, Kevin Barton, Robert M. Graham, Raymond A. Guenther, Larry Webber

Chemistry Faculty Publications

The Efficacy Of Chemistry Outreach Programs On Middle School Students, Erica M. Dumeyer

Mahurin Honors College Capstone Experience/Thesis Projects

Dna Linking Number Change Induced By Sequence-Specific Dna-Binding Proteins, Bo Chen, Yazhong Xiao, Chang Liu, Chen-Zhong Li, Fenfei Leng

Department of Chemistry and Biochemistry

Immobilization Of The Aminopeptidase From Aeromonas Proteolytica On Mg2+/Al3+ Layered Double Hydroxide Particles, Steven T. Frey, Stephanie L. Guilmet, Richard G. Egan Iii, Alyssa Bennett, Sarah R. Soltau, Richard C. Holz

Chemistry Faculty Research and Publications

Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, Dorjderem Nyamjav, Sergey Rozhok, Richard C. Holz

Chemistry Faculty Research and Publications

A Shortened Synthesis Of Optically Pure Tricarbonyl[Methyl (2e,4e)-6-Oxo-2,4-Hexadienoate]Iron Leading To Improved Yield, Rajesh K. Pandey, Sergey Lindeman, William Donaldson

Chemistry Faculty Research and Publications

Infrared Spectroelectrochemical Reduction Of Iron Porphyrin Complexes, Zhongcheng Wei, Michael D. Ryan

Chemistry Faculty Research and Publications

Thermal Degradation Studies On Pmma–Het Acid Based Oligoesters Blends, Thangamani Rajkumar, Chinnaswamy Thangavel Vijayakumar, Palanichamy Sivasamy, Bojja Sreedhar, Charles A. Wilkie

Chemistry Faculty Research and Publications

Sulfur K-Edge Photo-Fragmentation Of Ethylene Sulfide, Wayne C. Stolte, Gunnar Ohrwall

Chemistry and Biochemistry Faculty Research

An Improved Synthesis Of A Ring-C Precursor To Cobyric Acid, Hui Wang, Peter A. Jacobi

Dartmouth Scholarship

Fuel Efficiency Automobile Test Publications

Transition-Metal Ion Exchange Using Poly(Ethylene Glycol) Oligomers As Solvents, Gina M. Canfield, Michael Bizimis, Susan E. Latturner

Faculty Publications

Enantioselective Synthesis Of Bicarbocyclic Structures With An All-Carbon Quaternary Stereocenter Through Sequential Cross Metathesis And Intramolecular Rauhut-Currier Reaction, Yuan Qiao, Sanjeev Kumar, William Paul Malachowski

Chemistry Faculty Research and Scholarship

Noninnocent Dithiolene Ligands: A New Oxomolybdenum Complex Possessing A Donor-Acceptor Dithiolene Ligand, Kelly G. Matz, Regina P. Mtei, Belinda Leung, Sharon J. Nieter Burgmayer, Martin L. Kirk

Chemistry Faculty Research and Scholarship

Polystyrene-Supported Aluminum Chloride As An Efficient And Reusable Catalyst For Condensation Of Indole With Various Carbonyl Compounds, Bahman Tamami, Amir Nasrolahi Shirazi, Kaveh Parvanak Borujeni

Pharmacy Faculty Articles and Research

Major Challenges For The Modern Chemistry In Particular And Science In General, Vuk Uskoković

Pharmacy Faculty Articles and Research