Quantification and Scavenging Ability of Antioxidants in Bottled Tea

Bottled tea is made from brewed leaves of the Camelia sinensis plant. These leaves contain molecules called polyphenols that have aromatic rings with many alcohol groups. Different fermentation processes of the leaves lead to different types of tea, including black, oolong, green, and white tea. The polyphenols present in bottled tea have antioxidant properties, which have been seen to prevent certain types of diseases. Antioxidants work by stabilizing highly unstable free radicals, which are missing an electron in their orbital. Different studies have concluded contradictory results about which type of tea contains the highest quantity of antioxidants. There has been limited research in the activity of antioxidants in commercially brewed tea. The goal of our research is to analyze the quantity of different antioxidants present in bottled tea, and then analyze their effectiveness by examining their activity. Quantification is conducted with UV-Vis Photospectrometry to look at the total polyphenol content as well as individual classes of compounds. Reactivity is conducted to mimic a cellular response to the presence of a radical when there are polyphenols present, and to oxidize the polyphenols to measure their capacity for oxidation

Progress of a new instrument to study molecular dynamics of interstellar ion-neutral reactions

Astrochemistry, a relatively young field of research, addresses a gap in our understanding of molecular evolution in space. With many space missions gathering data, the number of unresolved spectral lines is growing rapidly. Each year there are about three new molecules that are identified in the interstellar medium (ISM). However, our understanding of molecular processes, branching ratios, and rates are at a beginner level. For instance, we do not yet understand the chemical processes associated with the creation and evolution of even the most basic molecules such as water and methanol in space. One of the important steps toward understanding the chemistry of the ISM is to identify, through laboratory and theoretical work, a list of potential target molecules that are likely to exist in the ISM. This work describes experimental progress towards building a spectrometer that is able to produce complex cold ions that will react with cooled neutral molecules under conditions similar to those in space. I plan to present the astrochemical needs that motivated my research, how the new instrument will meet those needs, and the present status of the instrument and measurements in my lab

bodies-cities:exploring embodied knowledge of urban sites through interactive virtual reality experiences

bodies-cities presents the multi-sensory complexity of embodied mapmaking as a layered, interactive virtual reality (VR) palimpsest. A palimpsest is a space that holds multiple layers of knowledge, and this research takes the urban public site of St James Town in downtown Toronto for its exploration. The research process exemplifies the entanglement of people, places, methodology, and methods to reflect the complex nature of embodied spatial knowledge. This entanglement is presented through the application of Karen Barad’s feminist new materialist theory and the apparatus of sensory ethnography for virtual reality. The virtual reality experience draws on the interactive affordances of VR and reconfigures film montage and architecture techniques to present the entangled elements of embodied knowledge emerging from residents’ relationship to the site

Detection and Quantification of Lead and Copper in Firearm Harvested Ground Venison Intended for Human Consumption

Most White-tailed Deer (Odocoileus virginianus) in Illinois are harvested with firearms that use lead or copper shotgun slugs or muzzleloader bullets, which may fragment when they strike bone. Lead is a neurotoxin to both humans and animals that scavenge deer that have escaped from hunters, and excess amounts of copper ingestion can impair lipid and DNA function. In a preliminary study in 2014, packets of ground venison from firearm and bow hunters in Illinois were x-rayed, and six out of ten firearm-harvested packets contained possible metal fragments. The purpose of this study is to utilize Anodic Stripping Voltammetry (ASV) and Atomic Absorption Spectroscopy to identify the presence and concentration of lead and copper in ground venison meat meant for human consumption. Current research and manipulation of test parameters and solutions has yielded ASV standard addition curves for both lead and copper solutions. Using this method we have been able detect lead in solution at levels of 300 µg/L, with predicted detections limits of 50-100 µg/L. This protocol will be used to analyze ground venison collected during the 2013 and 2014 deer hunting seasons

Instrumentation for Determining Prebiotic Species in the Interstellar Medium

Oral presentation abstract

Characterization of Phthalate Exposure among Pregnant Women Assessed by Repeat Air and Urine Samples

Background: Although urinary concentrations of phthalate metabolites are frequently used as biomarkers in epidemiologic studies, variability during pregnancy has not been characterized. Methods: We measured phthalate metabolite concentrations in spot urine samples collected from 246 pregnant Dominican and African-American women. Twenty-eight women had repeat urine samples collected over a 6-week period. We also analyzed 48-hr personal air samples (n = 96 women) and repeated indoor air samples (n = 32 homes) for five phthalate diesters. Mixed-effects models were fit to evaluate reproducibility via intraclass correlation coefficients (ICC). We evaluated the sensitivity and specificity of using a single specimen versus repeat samples to classify a woman’s exposure in the low or high category. Results: Phthalates were detected in 85–100% of air and urine samples. ICCs for the unadjusted urinary metabolite concentrations ranged from 0.30 for mono-ethyl phthalate to 0.66 for monobenzyl phthalate. For indoor air, ICCs ranged from 0.48 [di-2-ethylhexyl phthalate (DEHP)] to 0.83 [butylbenzyl phthalate (BBzP)]. Air levels of phthalate diesters correlated with their respective urinary metabolite concentrations for BBzP (r = 0.71), di-isobutyl phthalate (r = 0.44), and diethyl phthalate (DEP; r = 0.39). In women sampled late in pregnancy, specific gravity appeared to be more effective than creatinine in adjusting for urine dilution. Conclusions: Urinary concentrations of DEP and DEHP metabolites in pregnant women showed lower reproducibility than metabolites for di-n-butyl phthalate and BBzP. A single indoor air sample may be sufficient to characterize phthalate exposure in the home, whereas urinary phthalate biomarkers should be sampled longitudinally during pregnancy to minimize exposure misclassification

Electronic spectroscopy and dissociation dynamics of gas-phase transition metal containing cations and dications

Studies of gas-phase ionic clusters have become an integral component in understanding microsolvation and catalysis by transition metal cations. Further interest in this field is due to the possibility of bridging the gap between the condensed and gas phases by developing our understanding of clusters and the possibility that small clusters can have unique chemical and catalytic properties. Most gas phase studies have focused on singly charged ions. Electrospray allows for the production of multiply charged ions solvated by a few solvent molecules. Understanding smaller reactive species such as metal centered clusters with well-defined, gas phase conditions also allows for detailed comparison between theory and experiments. In these studies the main focus is to understand bond activation by transition metal cations and solvation of transition metal dications. The gas phase ions of interest are studied using an electrospray-ionization or laser-ablation dual time-of-flight mass spectrometer and are characterized using photofragment spectroscopy in the visible and ultraviolet regions of the spectrum. Photofragment spectroscopy is a powerful method that can be used in gas phase studies to gather a wealth of information on the ions’ bond strengths, spectroscopic constants, and dissociation kinetics and dynamics. The study of TiO+(CO2) spectroscopy (Chapter 3) was a result of study of CO2 bond activation by Ti+ that went on to provide a wealth of information on the spectroscopy and dissociation kinetics of this molecule. An electronic transition of the TiO+ chromophore was observed, 2Π←2Δ, revealing new information about the excited state and the effect of TiO + electronic state on the metal-CO2 ligand interaction. The photodissociation spectrum of this molecule is well resolved and shows progressions in the covalent Ti-O stretch and metal-ligand stretch and rock. The lifetime of electronically excited TiO+(CO 2) was measured, and depends strongly on vibrational energy. Calculations on TiO+ and TiO+(CO2) were combined with experimental results on TiO+(CO2) to predict spectroscopic transitions of TiO+, an astrophysically interesting molecule. The photodissociation dynamics of M2+(CH3CN)n(H 2O)m where M = Co and Ni, (Chapter 4) is important in understanding the gas phase microsolvation of metal dications. The coordination number and type of solvent affect the dissociation pathways. M2+(CH 3CN)n (n\u3e2) primarily lose a solvent molecule. Electron transfer is a minor channel for n=3 and is the only channel observed for n=2. Mixed clusters M2+(CH3CN)n(H2O)m preferentially lose water. Loss of acetonitrile is a minor channel, as is proton transfer. Water is the proton donor. Replacing acetonitrile with water increases the proton transfer channel. Nickel and cobalt complexes show similar dissociation dynamics, with proton transfer more likely for nickel complexes. Methane activation by transition metal catalysts is industrially important as it can be used to produce gasoline from natural gas. We studied the products and intermediates of the reaction of laser-ablated platinum atoms with methane (Chapter 5). Photoionization efficiency curves were measured for PtCH 2 and the [H-Pt-CH3] insertion intermediate using tunable vacuum ultraviolet light. The resulting ionization energies were combined with bond strengths for the cations to derive bond strengths for the neutrals. These were used to construct a potential energy surface for methane activation by platinum atoms

Sinhala: හිවලුන් සහ මිදි [hivalun saha midi] The Fox and the Grapes

Based on the classic Aesop fable, this story has the following moral: There are many who pretend to despise and belittle that which is beyond their reach.https://digitalcommons.iwu.edu/globalstorytelling/1012/thumbnail.jp