Margaret Phillips
New College of Florida
Michl Group
Project Title: 10-Vertex Carborane Derivatives for
Evaluation as Molecular Insulators
Abstract: Synthesis and full characterization of the 10-vertex carborane derivitives (1,10-dicarba-closo-decaboranes) are reported. These compounds may serve as molecular electronic insulators when coupled between donor and acceptor molecules.
Aron Fast
Southwestern College
Vaida Group
Project Title: Physical Chemistry of Organic Films on Aqueous Solutions
Abstract: Our research explores the physical chemical properties of organic
films on aqueous solutions. The monolayer is a two dimensional representation
of the surface of an organic atmospheric aerosol.
Atmospheric processing through kinetic pathways may affect
its optical properties and chemical pathway. We examined the molecular
competition in binary mixtures of short and long-chain organic acids.
Our data shows that long-chain carboxylic acids are favored
over short-chain acids through time in a mixed organic monolayer.
The second part of our research examined the solubility of
small organics in a stearic acid monolayer.
Data from isoprene, a water insoluble molecule, suggests small
organics may be transported to the troposphere on aerosols without chemical
processing.
Matt Larson
Ohio State University
Lineberger Group
Project Title: GRENOUILLE Characterization of Ultrashort Laser Pulses
Abstract: The burgeoning growth of ultrafast laser applications in industry, medicine, and academic research over the past decade has necessitated advancements in ultrashort laser pulse characterization. The interaction of an ultrashort pulse with a chemical or biological system depends on the nature of the pulse. For example, by varying the duration and repetition rate of ultrashort pulses, an ultrafast laser can be used to make ablations in tissue at precise, variable depths. Through ultrashort laser pulse characterization, a “fingerprint” of the generated pulse is obtained, allowing for the determination of the temporal profile, frequency spectrum, and phase structure of the pulse.
Wellesley College
Phillips Group
Project Title: Asymmetric Synthesis of Streptenol A
Abstract: (+)-Streptenol A [fig 1] was isolated from
the Streptomyces species of bacteria by Keller-Schierlein, W.
et al by a fermentation process.
It is closely related to Streptenol B, C, and D, which, including A, show
inhibition of cholesterol biosynthesis.
Streptenol A is unique in that it possesses anti-tumor and immuno-stimulating
activity as well. (+)-Streptenol
A also is a useful building block in chiral organic synthesis .
Previous syntheses of Streptenol A have been demonstrated in two
instances by Enders et al and Blechert et al.
The synthesis shown in this paper is significantly shorter than
either of the previous.
Bates College
Jonas Group
Project Title: Temperature Dependence of Polar Solvation Dynamics
Abstract: Polar and non- polar dynamics are probed using structurally similar molecules. Temperature dependent absorption measurements of IR144, a polar molecule, were compared to HDITCP, a structurally similar non-polar molecule. The absorption spectra of IR144 shows a blue shift for decreasing temperature values. In comparison the HDITCP shows a red shift. The red shift in HDITCP has been accounted for by non-polar polarizability solvation when both temperature and solvent are varied. For IR144, polar orientational solvation accounts for the solvent dependence of the electronic behavior however temperature dependence is dominated by changes in the solute-solvent distance.
University of Cincinnati
Kuchta Group
Project Title: The Study of Primase-Helicase in Herpes
Abstract: The herpes family includes a wide array of viruses including herpes simplex, varicella zoster and the cytomegalovirus. Herpes simplex 1 usually causes only minor irritations in healthy patients, but to those with weakened immune systems, such as newborns, the elderly, and AIDS patients, the virus can blind and even kill. Modern drug therapy has primarily focused on targeting the herpes DNA polymerase. As an alternative mode of therapy, we seek to understand the mechanism behind another enzyme essential for DNA replication: the helicase-primase complex. This unit is a single protein with two distinct activities. The effects of three nucleotide analogs were studied-- Ara ATP, Benzimidazole Triphosphate and Difluoro Benzimidazole Triphosphate-- as potential inhibitors of herpes primase. Earlier research suggested nucleotide analogs activated herpes primase activity prior to inhibition. Our research aimed at verifying this activation as a function of these two enzyme activities. Instead, we found no indication of initial stimulation before inhibition of the primase enzyme. This approach at targeting the activity of the primase helicase enzyme could potentially lead to new drug therapy to combat the herpes virus.
North Carolina State University
Tolbert Group
Project Title: Hygroscopic Behavior of Ammonium Sulfate/Organic Bulk Solutions
Abstract: Studies show that organic compounds may influence the water uptake of many inorganic aerosols, such as ammonium sulfate. In the laboratory, organics mixed with inorganic aerosols have been found to lower the deliquescence of many inorganics found in the troposphere. However, influences on hygroscopic growth from organic fractions mixed with inorganics beyond the deliquescence point are still uncertain. This study used eutonic mixtures to represent aerosol particle growth beyond the deliquescence point. The solutions were diluted by adding aliquots of water and then measuring their vapor pressures in an evacuated glass line system. We found that glutaric, malonic, and L-malic acid eutonic mixtures took up less water than pure ammonium sulfate at high relative humidities.
University of Colorado, Boulder
Nesbitt Group
Project Title:
Abstract: The high resolution infrared spectrum of 1,3-butadiene was
measured at 12 K in the range of 3010 to 3045 cm-1 using a difference frequency
laser generation spectrometer and slit jet expansion. A vibrational band
of the trans conformer was discovered in this region. A least squares fit
of the data yielded rotational constants in the ground state of 41.6818 GHz,
4.4334 GHz, and 4.0079 GHz.
Rowlen Group
Abstract: The fluorescence signal for stained, free-floating DNA is quenched with salt in order to determine the number of virus particles in a contaminated solution. A Hitachi F-2000 Fluorescence Spectrophotometer was used to measure the fluorescence intensity of DNA at different concentrations (ng/ml). The DNA was then combined with a salt solution at different concentrations (mM), stained and the fluorescence signal was measured in order to determine the extent of salt-induced fluorescence quenching. The results were processed as a Stern-Volmer quenching plot. The quenching constant kq for NaCl was found to be 0.0383 and the quenching constant kq for MgCl2 was 0.1178. The effective quenching of fluorescence, obtained from staining free-floating DNA, with salt may help explain why viruses can be effectively counted in flow cytometry.
Cumberland College
Rowlen Group
Project Title: Surface Enhanced Raman Scattering on Silver and Gold Colloidal Particles
Abstract:
Southern Oregon University
Liu Group
Project Title: Purification and Characterization of Smad4 Complexes
Abstract: Smad proteins are intracellular mediators of the transforming
growth factor-b superfamily. We have developed a purification method that
allows for the
isolation of Smad4 complexes being expressed at endogenous levels in mammalian
cells. A Smad4 cassette that includes two consecutive IgG-binding sites,
a TEV
cleavage site, and an M2 binding site was inserted into the genome of mouse-myoblast
cells. Cells that expressed endogenous levels of Smad4 were
selected and cultured. Two steps of Fast Protein Liquid Chromatography
(FPLC) were used to segregate the Smad4 complexes from a majority of cellular
proteins
and nucleic acids, followed by immunoprecipitation to complete the complex
isolation. We have found that, prior to immunoprecipitation, endogenous Smad4
elutes in tandem with recombinant Smad4, yet immunoprecipitation allows
for the selection of complexes that contain recombinant Smad4.