Chemistry Recent Senior Research Projects

Mariam Khalifeh "The Effects of Water Soluble Fiber Combined with Poly- and Monounsaturated Fatty Acids on Plasma Lipoprotein Levels in Hypercholesterolemic Rats." 2011 Pennsylvania Academy of Science Oral Presentation.

Abstract: Hypercholesterolemia is a metabolic disorder characterized by elevated concentrations of circulating plasma low density lipoproteins (LDL). Hypercholesterolemia is directly associated with an increased risk for coronary artery disease. Pharmacological treatments for hypercholersterolemia result in adverse side effects and have been associated with potential carcinogenicity. Recent research has suggested that natural approaches and nonpharmacologic interventions, consisting largely of dietart modifications, are advocated as a firstline treatment for hypercholesterolemia. Olive oil, fish oil, and rice bran oil are rich in monounsaturated (MUFA) and polyunsaturated fatty acids(PUFA), which affectplasma cholesterol metabolism via different mechanisms. Furthermore, oat bran, an important source of water-soluble fiber, is recognized as a potential hypercholesterolemic dietary component. This study investigated the efficacy of three diets, combining each of the unsaturated oils with oat bran, in lowering plasma cholesterol levelsin hypercholesterolemic rats. In order the determine the effectiveness of each diet, plasma samples were collected from the rats, and quantitative ananalysis of plasma lipoproteins was performed using high performance gel filtration chromatography (HPGC). The results of this study will provide insights about how PUFAs, MUFAs, and water-soluble fiber may be used in combination diets to reduce plasma cholesterol concentrations in hypercholesterolemic patients.

Megan Dennis "Comparing Vitellogenin Induction by 17β-estradiol in Male Danio rerio Through a Tritrophic Bioaccumulation Model and a Bioconcentration Model." 2011 Pennsylvania Academy of Science Oral Presentation.

Abstract: The steroid hormone 17β-estradiol (E2) is excreted into the water by humans and is not filtered by sewage treatment plants. Its presence in the aquatic ecosystem is causing a disruption of the functioning ability of many aquatic organisms. Being lipophilic allows 17β-estradiol to be stored in primary producers, giving E2 the ability to possibly bioaccumulate up the food chain. The chemical E2 can also bioconcentrate in aquatic species, specifically fish, which implies it can be accumulated through non-dietary routes. A tritrophic model, using diatoms (Navicula radiosa), daphnia (Daphnia pulex), and zebrafish (Danio rerio) will serve to evaluate the bioaccumulation and potential trophic transfer by exposing diatoms to E2. A second bioconcentration model will determine the ability of E2 to concentrate in D. rerio via direct exposure of water treated with E2. In both of these experiments, quantification of vitellogenin (Vtg) production by D. rerio will be compared between treatments using an ELISA. It is expected that elevated Vtg levels will be found in the D. rerio treated with E2, in both models. The results obtained will be analyzed by a multi-variable ANOVA and Bonferroni post hoc.

Capulet Williams “Detectable Limits of Blood Using Luminal Following Exposure to Extreme Heat of Fire.” 2010 Pennsylvania Academy of Science Poster Presentation.

CWilliams image.jpg Abstract: Luminal, which produces chemiluminescence upon oxidation, is frequently used to detect blood at crime scenes as only one per per milliom (ppm) of blood is necessary for a detectable signal. Forensic scientists and law enforcement officers often encounter situations where attempts have been made to cover up or destroy evidence by the use of arson. In this study, the detection limit of blood following exposure to the extreme heat of fire was investigated. Fluorimetry was utilized to determine whether the intensity of chemiluminescence was linearly related to concentration of blood and to determine whether the intensity of chemiluminescence changed when blood was exposed to heat. Trends indicate that blood exposed to heat produces a higher intensity of chemiluminescence verses blood that has not been exposed to heat. Blood at various dilutions (0.01 ppm – 100 ppm) was then qualitatively analyzed before and after exposure to the extreme heat of fire. A controlled burn of wood pallets treated with the same dilutions of blood was done in cooperation with the Franklin County Public Safety and FireTraining Center. The pallets will be treated with luminal and examined qualitatively and quantitatively using a digital fluorescence imaging system.

Ashley Mudd. "An Inquiry into the Existence of a Relationship between β-carotene and Tetrachloroisophthalonitrile Fungicide Residue levels in Raphanus sativus." 2009 Pennsylvania Academy of Science Oral Presentation.

Abstract: The lipophilic compound β-carotene serves as a precursor to vitamin A (retinol) in animals, which is essential in the proper functioning of light-sensitive nerve cells in the retina. Prior studies have focused primarily on the increase of phytochemical bioavailability within the human system, but have not examined the potentiality of a positive correlation between the non-polar phytochemical, β-carotene and bioaccumulation of non-polar biocides. Over 11 million pounds of the non-polar fungicide tetrachloroisophthalonitrile are applied annually to vegetables and fruits in the U.S. as a deterrent for fungal diseases. Tetrachloroisophthalonitrile was applied weekly to four varieties of Raphanus sativus (Rainbow, Zlata, Mooli, Mantanghong). Variables affecting plant stress and health were monitored, including soil pH, moisture, temperature and light-exposure. Foliage and root samples were analyzed for β-carotene content using HPLC/UV-vis and tetrachloroisophthalonitrile content using an enzyme immuno assay.