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its rate of carbon uptake is greater than its rate of release. Therefore, investigating what will happen to this carbon sink is necessary for understanding future environmental change. We used the Community Land Model version 4 (CLM4CN) and ran 8 simulations with varying atmospheric changes. Half of the simulations were run with present climate, using Qian atmospheric forcing data for 1948 to 2004, and half were run with climate from 2075 to 2100, with the atmospheric forcing data coming from the Representative Concentration Pathways 8.5 scenario (RCP8.5). One run from each group was forced with an increased carbon dioxide (CO2) concentration of 937.87 parts per million (ppm); another was forced with an increased tropospheric ozone (O3) concentration projected at the year 2100 with the Community Atmosphere Model (CAM) and RCP8.5 scenario; the third included a combination of increased O3
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and CO2 concentrations; and the fourth was a control. We are using the National Center for Atmospheric Research Command Language (NCL) to analyze these simulations. We expect carbon pools to increase in scenarios where carbon fertilization plays a large role due to increased CO2, and we expect changes due to increased tropospheric O3 and climate change. Our results will show which simulations will be most favorable in maintaining the Pacific Northwest’s status as a carbon sink.
CHEMISTRY (EXCEPT BIOCHEMISTRY)
DEVELOPMENT OF SMALL-MOLECULE INHIBITORS OF CYTOKINE-INDUCED BETA CELL APOPTOSIS WITH
IMPROVED METABOLIC STABILITYAngel Placeres, Stephen Scully, Alicia Tang, Bridget Wagner.
Broad Institute of Harvard and MIT, Cambridge, MA.
Diabetes is a metabolic disorder characterized by high blood glucose levels. It affects 8.3% of the population in the United States and is one of the leading causes of death. In type 1 diabetes (T1D), autoimmune destruction of pancreatic beta cells leads to lowered production of insulin, an essential hormone for the regulation of glucose. To discover novel therapies for T1D, our group screened for small molecules that inhibit immune-mediated death of beta cells for the recovery of insulin levels. BRD0476, a small molecule developed by diversity-oriented synthesis (DOS), was found to be an effective inhibitor of cytokine-induced beta-cell apoptosis. In the present study, we describe the design and synthesis of analogs of BRD0476 with increased metabolic stability. This is associated with the susceptibility of compounds to undergo biotransformation for the selection and development of drugs with favorable pharmacokinetic properties. In particular, we describe the design of naphthyl analogs with incorporation of electronwithdrawing groups to prevent oxidative metabolism mediated by CYP450 enzymes. The development of biologically active analogs of BRD0476 that are metabolically stable may prove to be a novel intervention for the treatment of type 1 diabetes.
RECOGNITION OF SACCHARIDE BIOMARKERS VIA A FLUORESCENT PROBE BASED ON BORONIC ACID
APPENDED BIPYRIDINIUM SALTSIsaac Banda, Angel Resendez, Kelsey Clarke, Bakthan Singaram.
University of California, Santa Cruz, Santa Cruz, CA.
Gastrointestinal barrier dysfunction is now recognized as an early event in the pathogenesis of several problematic diseases such as inflammatory bowel disease (IBD), Parkinson’s disease, Crohn’s disease, celiac disease, and type 1, 2 diabetes mellitus. Gastrointestinal permeability can be assessed noninvasively by analyzing saccharide biomarkers in urine such as sucrose for upper GI permeability, lactulose and mannitol for small intestine permeability, and the synthetic sweetener sucralose for colon. Current methods for analyzing these biomarkers require expensive and time-consuming instrumentation such as high performance liquid chromatography/mass spectrometry (LC/MS).
Currently, there is a need for rapidly quantifying these biomarkers in a high-throughput, low-cost effective manner.
Using a 2-component system that utilizes a fluorescent probe that serves as the reporter signal and boronic acid substituted bipyridinium salts that serves as the receptor, the detection of the saccharide biomarkers mannitol and lactulose were examined in a buffered solution. Results indicate the bis-substituted viologen receptor has a greater fluorescence restoration whereas the mono-substituted viologen has slightly higher discriminatory properties.
KINETIC SPECTROPHOTOMETRY AND FLUORESCENCE FOR NEW QUANTIFICATION OF ROCKET FUELRESIDUES Geri Bigtacion, Henry Largo, Andrew Jones, Trinh Nguyen, Mian Jiang.
University of Houston-Downtown, Houston, TX.
Residues from rocket launching are unavoidable by-products of human space exploration. These residues are usually oxidizing species. To quantify them has significance to drinking water compliance, waste minimization, and hunting for life-sustaining exoplanets. In this work we developed a new assay for these oxidants by using fluorescence direct and indirect determination. Our results showed that the indirect approach (i.e., fluorescence quenching) is more sensitive
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than the direct luminescence. We systematically examined the staining dyes and pigments used in cell biochemical study and their fluorescence and found thiazine-containing dyes are quenching upon introducing the oxidants. By utilizing kinetic analysis, this quenching can be developed into a new assay for the oxidants. The preliminary study revealed the complicated responding mechanism. While these oxidants (analytes) can directly oxidize these dyes, they actually play a role more like the quenchers to the existent fluorescence of the dyes impacted by a stronger third oxidizer agent. The follow-up study optimized the analytical system. The highest sensitivity has been obtained in acidic media with ternary component system matrix. Our new protocols for nitrite and hypochlorite are representative and can be extended into other oxidizers which adds new meaning to the existent analytical arsenal in addressing environmental protection and space exploration. [This work was supported by NASA-TSGC-NIP, SACP-UARP, Starter-award of UARP, and Welch Grant ( BJ-0027 )].
STUDY OF THE THERMOTROPIC AND LIGHT-EMITTING PROPERTIES OF POLYPYRIDINIUM SALTS DERIVED
FROM NAPTHDINEDat Truong, Robin Jose.
University of Houston-Downtown, Houston, TX.
A novel polymer was synthesized from 4,4′-(1,4-phenylene)bis(2,6-diphenylpyrilium) tosylate and 3,3′-dimethylnaphthidine. Tosylate counterion was exchanged with triflimide, 1-napthalene sulfonate, and 2-napthalene sulfonate to yield 4 polypyridinium salts. The structures and purities of those polymers were established by Fourier transform infrared (FTIR), Fourier transform nuclear magnetic resonance (FTNMR), and elemental analyses. Molecular weights of those polymers were determined by gel permeation chromatography (GPC). Their thermotropic properties were studied by using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Their light-emitting properties were determined by UV-visible (UV-Vis) spectroscopies and fluorescence. The results show more liquid crystalline phases during melting transitions, electroluminescent properties, and improved solubility in polar solvents of those polypyridinium salts. The results also show that the thermotropic properties of these polymers can be tuned by the nature of the counterions. On the other hand, the light-emitting properties of those polymers are independent from these counterions, and thus the emission maxima of those polymers are not influenced.
PREPARATION OF PROTEIN-BRANCHED GLYCOPOLYMER CONJUGATESMaltish Lorenzo, Nicholas Matsumoto, Heather Maynard.
University of California, Los Angeles, Los Angeles, CA.
Protein-polymer conjugates are of interest in the development of new biologically-based therapeutic agents. Currently, protein-poly(ethylene glycol) (PEG) conjugates are employed in the treatment of hepatitis and cancer. We have recently reported the conjugation of trehalose-based synthetic glycopolymers to proteins. The protein-trehalose polymer conjugates were demonstrated to retain biological activity after being exposed to extreme environmental conditions that are known to decrease protein activity, such as prolonged heating and multiple lyophilization cycles.
Polymer architecture may influence the activity of bioconjugates. Most polymers used for conjugation to proteins are limited to linear architectures, and there are few examples of the preparation and study of protein-branched polymer conjugates. Our research is focused on developing a methodology for the preparation of branched trehalose glycopolymer-protein conjugates. The strategy involves a 2-step approach. First, a linear polymer scaffold containing multiple atom transfer radical polymerization (ATRP) initiators will be grafted to the protein. The linear scaffold will be prepared by nitroxide-mediated co-polymerization (NMP) of styrenyl trehalose monomer and an ATRP-initiating monomer. Second, ATRP will be employed to graft styrenyl trahalose from the protein-polymer scaffold to produce the branched glycopolymer conjugate. The branched and linear glycopolymer conjugates will be compared with respect to activity and stability to elucidate the effects of polymer architecture on these parameters.
MESOPOROUS MATERIALS FOR THE DESULFURIZATION OF JET FUELJoshua Gardner1, Jessica St John2.
Cabrillo College, Santa Cruz, CA, 2University of California, Santa Cruz, Santa Cruz, CA.
1 Jet fuel with ultra-low sulfur content is a promising feedstock for use in hydrogen fuel cells. Current desulfurization techniques, such as hydrodesulfurization, are ineffective on these fuels which has given rise to the field of adsorptive
desulfurization. Mesoporous inorganic materials loaded with metals that have high affinities for sulfur have been shown to be promising for desulfurization. We can synthesize these materials using surfactants as templating agents and metal alkoxides as precursors; the templates are then removed, leaving a porous material that can be loaded with a metal such as silver. Various metal-loaded mesoporous materials were created for testing against a model jet fuel to ascertain which metals and frameworks had the highest adsorption capacities. Mesoporous silica loaded with silver was found to be a promising sorbant for desulfurization of jet fuel.
COMPUTATIONAL STUDIES OF MANGANESE-ENHANCED MAGNETIC RESONANCE IMAGING CONTRASTAGENTS Mariana Cortes, Maria Benavides.
University of Houston-Downtown, Houston, TX.
Manganese-enhanced magnetic resonance imaging (MEMRI) agents are emerging in the market as alternative contrasting agents to the more commonly used Gd complexes. These manganese-based complexes are increasingly used in imaging, from the nervous system to the kidneys, due to the metal shortening the T1 as well as the T2 relaxation times of surrounding water. Manganese chloride (MnCl2) is commonly used in brain imaging due to the agent being able to identify cytoarchitecture within the brain, as studied in rats. Although MnCl2 is not FDA approved, a contrasting agent on the market that is approved is manganese dipyridoxaldiphosphate, or mangafodipir (MnDPDP).
This complex is commonly used for imaging the liver or cardiac ischemia. To further understand these complexes, we examined various properties of these two agents using Gaussview 09 and Gaussian 09. Both molecules were optimized and had their frequencies found at ground state using the density functional theory with the functional B3LYP and basis state SDD. We found that MnDPDP was highly polar with a dipole moment of over 10 debye, while MnCl2∙4H2O was nonpolar having a dipole moment of 0 debye. When comparing our computed data with experimental results, we found that our infrared spectra had very similar peaks and almost identical fingerprints to the literature.
Along with the similar IR spectra, the bond distances and angles were over 95% in agreement to those found experimentally. We are further analyzing our complexes in order to better understand their chemical nature.
NEW PLATINUM(II) COMPLEXES FOR THE INVESTIGATION OF COPPER-MEDIATED DEGRADATION IN PTBOUND RNA CLICK REACTIONSLindsay Guzman, Victoria DeRose.
University of Oregon, Eugene, OR.
Small-molecule binders, such as the platinum(II) [(Pt(II)] anticancer drug cisplatin, can be used to probe cellular RNA structures and functions. We are focusing on the functionalization of Pt complexes with azide and alkyne moieties that may allow for the subsequent purification and high-throughput sequencing of Pt-RNA adducts in the coppercatalyzed Huisgen cycloaddition reaction. Because of the reactive nature of the necessary Cu catalyst, it is speculated that Cu is facilitating observed RNA degradation in model reactions, thus lowering the efficiency and usefulness of the post-treatment click modifications. Three new Pt(II) complexes that vary in linker length from the platinum center to the copper-catalyzed click reaction site will be synthesized to probe the possible influence of click-mediated Cu recruitment on cleavage of the oligonucleotide. This will allow for further investigation of additional and undesired copper-mediated reactivity and improved yield of Pt-bound RNA click reactions.
SIZE SELECTION OF HIGH DIELECTRIC NANOPARTICLESKatia Nava, Justin Cortez, Brittnee Veldman.
California State University Channel Islands, Camarillo, CA.