June 27, 2003
Chen, Yian. 2003. Synthesis of New Naphthalimide for Tissue-Bonding in the Meniscus. (Dr. Robert Kane - Chemistry).
Tissue-bonding is an area of research into methods for cross-linking of proteins in human tissue. One of the most debilitating disorders of the knee, a torn meniscus, may potentially be treated with agents that induce tissue-bonding. The meniscus is a floating layer of cartilage contained in the knee; it does not receive adequate blood flow and therefore cannot heal properly on its own. Often, surgical procedures are required to repair or remove it. However, certain compounds called naphthalimides have shown the potential to induce protein cross-linking when exposed to light. As our research project, we synthesized a new anionic naphthalimide with the purpose of testing its effectiveness as a cross-linking agent. This was completed in a three-stage synthesis process beginning with the starting material 1,8-naphthalic anhydride. From there, we added and removed different functional groups before finally ending with the product, a naphthalimide that has not yet been tested. Because organic reactions do not always display perceptible changes between starting material and product, we utilized thin-layer chromatography and nuclear magnetic resonance imaging as tools for the purpose of detecting reaction completion. Following the synthesis, we tested the product using gel electrophoresis. Our final product is unique because it is anionic in buffer solution and has carboxylic acid groups attached to it.
Gupta, Ankur. 2003. Synthesis of Combretastatin Analog as a Vascular Targeting Agent. (Dr. Kevin G. Pinney - Organic Chemistry).
Cancer is a devastating disease which has remained relatively unscathed by conventional treatments. Cancer's severity has inspired many new fields of research and several potential methods of curing the disease. One such method is Vascular Targeting. The general approach of this method is to deprive tumors of the nutrients required for proliferation, and thus, to eliminate them. This is accomplished by synthesizing molecules that selectively target the immature endothelial cells lining newly formed blood vessels that tumors create through angiogenesis. After being incorporated by the endothelial cells, these molecules, namely Combretastatin A-4P and its closely related analogs, link to the beta subunits of tubulin molecules in the Microtubule Organizing Center. Then, they disrupt the microtubule-based cytoskeleton and induce morphology changes in the cells. Among the morphology changes is a widening of the endothelial cells along the blood vessels, which in turn occludes the vessels and prevents blood flow. This seems to be a certain cure to cancer. However, these compounds do not have complete specificity for tumor vasculature or sufficient therapeutic windows; thus, they have a certain level of cytotoxicity and inefficacy. To optimize the molecules' functionality, the Pinney Research Group, among many collaborators worldwide, synthesizes carefully conceived analogs of Combretastatin. Among these was 3-Methoxy-8-(3,4,5-trimethoxy-phenyl)-6,7-dihydro-5H-benzocycloheptene. Closely related to other clinically successful compounds, it was synthesized using 5 major reactions with a 34% yield. Once synthesized, this and other novel molecules are sent off for testing and clinical trials. These clinical trials determine the compound's ability as a Vascular Targeting Agent.
Juloori, Aditya. 2003. Nidogen and Stress Factors in Caenorhabditis elegans. (Dr. Myeongwoo Lee - Biology).
The Extracellular Matrix (ECM) plays an important role in the function of cells of all organisms, including the nematode, C. elegans. ECM functions to provide structural support for the cell and to allow a medium for cell migration and interaction. One type of highly specialized ECM is the basement membrane (BM). Lying between epithelial and muscle tissue, the basement membrane is made up chiefly of laminin, type IV collagen, proteoglycan, and nidogen. Like any other proteins, these each have respective genes in the C. elegans genome to control their function. When any of the major BM proteins loses function because of genetic alteration, the C. elegans organism dies. This is, except for nidogen. Even when nidogen loses its function, the organism continues to live on. Our research group wanted to know more about nidogen's purpose in the ECM. Three strains of organisms were used: N2 (wild type), CH118 (truncated nidogen), and CH119 (deleted nidogen). We subjected the 3 strains of C. elegans to heat and ultraviolet stress. Both experiments showed that the wild-type strain lived longer than the mutants, which lacked fully functioning nidogen. Thus, nidogen provides the ECM and therefore the cell with the ability to handle stress and survive. A generally accepted idea in biology is that organisms best equipped to survive stress are the ones that will live the longest. In essence, by providing cells with the means of withstanding stress factors, nidogen is playing a role in prolonging the lives of C. elegans.
Wang, Joyce. 2003. Cracking Hydrogen Gas. (Dr. Kenneth T. Park - Laboratory for Surface Analysis and Modification).
Surface science is the study of the chemical composition, the physical structure and appearance, and the level of trace impurities of the outermost layer of the sample being examined. In order to study the pure samples, hydrogen is applied onto the surface of the sample being studied; however since the hydrogen molecule will not be readily adsorbed, the dissociation of hydrogen is necessary. The purpose of adsorbing hydrogen onto the surface of sample is for semiconductor substrate cleaning and passivity. After the atomic hydrogen is adsorbed, scientists study the interaction of hydrogen with the surface of the sample, and that information allows manufacturers to create better products in modern technologies such as electronics. In order to achieve this, I designed and constructed a thermal gas cracker that cracked hydrogen through direct heating of the filament. Because my thermal gas cracker tested negative for cracking hydrogen, I developed another thermal gas cracker that cracked hydrogen through electron bombardment heating. Due to the lack of time, I was not able to build my latter design but hope that it will have the ability to crack hydrogen.
Chen, Melissa. 2003. Time Scales Calculus. (Dr. John Davis - Mathematics).
Time scales calculus is a theory invented by Stefan Hilger in his 1988 Ph.D. dissertation. Differential calculus describes continuous case while difference calculus describes discrete cases. Time scales calculus unifies and extends both of these theories and provides a framework for so-called "time scales" which have both discrete and continuous parts. In this project, we compare and contrast the different types of calculus and mention some applications of time scales. We also include examples of various time scales. Finally, we solve the prototypical dynamic equation: the delta derivative of y=y, on an arbitrary time scale and show that the solution is a generalized exponential function.
Kadakia, Vishal. 2003. Lattice Structure, Wave Dispersion, and Inter-particle interactions in Complex Plasmas. (Dr. Truell Hyde and Dr. Lorin Matthews - Physics).
Plasma, the fourth state of matter, has become the focus of much scientific inquiry. At the head of these explorations is complex plasma. Complex Plasma is normal plasma amalgamated with comparatively large colloidal particles. The gas, from which the plasma is created, separates into ions and electrons by a potential difference. Since the electrons have a smaller mass and therefore a higher velocity, they assail the colloidal particles-which in this case are small dust particles-at a higher frequency; consequentially, the dust particles accumulate a negative charge. These negatively charged dust particles influence the ions, electrons, and other dust particles surrounding it. This influence can be modeled theoretically-by computer-and experimentally. Using a quaternary data tree the computer calculations are done rapidly and accurately. Examining wave propagation along the lattice is the most useful purpose of the computer analysis. The cell, where the experimental analysis is done, places the negatively charged particles into an electric field to levitate them above the lower electrode. A monolayer of these levitated particles can be compared to the characteristics of the theoretical particle predictions: lattice structure, wave dispersion, and inter-particle forces are examples of such comparisons. For accuracy, Argon gas is used in experimentation. Argon, a non-reactive noble gas, is heavy which makes the ions heavier; consequentially, the dust particle obtains a higher negative charge than it would for a lighter noble gas. In the end, various undetermined effects can be determined from the inconsistencies between theoretical predictions and experimental findings.
Moore, Marianne. 2003. Environmental Enrichment of Two Primate Species at the Cameron Park Zoo. (Heidi Marcum - Environmental Studies)
While it is impossible to determine if a captive animal is "happy," it is thought that the more a captive animal behaves like its counterparts in the wild, the more psychologically healthy it is. However, most captive animals are not given the opportunity to exhibit behaviors they would normally exhibit in the wild. Natural behaviors such as foraging, social interactions, and antipredator behavior are impossible in the traditional zoo enclosure, where animals are housed singly or in small groups, food is pre-processed and placed in bowls and the animals are free from predation. A relatively new field, called environmental enrichment, attempts to encourage more species-specific natural behaviors in captive individuals. We worked with two species at the Cameron Park Zoo, working to promote the psychological well-being of two primate species: the white-handed gibbons (Halobates lar) and the squirrel monkeys (Squimiri sciureus). We first observed the gibbons and squirrel monkeys, to determine which problems exist in their enclosures that may discourage natural behavior. We them determined some possible solutions, and introduced our various ideas to the animals. The enrichment devices we introduced were aimed at increasing the amount of time the primates spent foraging and moving, while decreasing inactivity and stress. We provided them with puzzle feeders, toys and other novel objects, and changed the architecture of their enclosures to allow them to get the most out of the space. Our results showed that relatively minor changes and activities increased the animals' locomotion and foraging, showing that primates can benefit from environmental enrichment.
Degnan, Andrew and Rushita Patel. 2003. Sulfur Dioxide-Impregnation of Biomass for Ethanol Production. Baylor University. (Dr. G. Peter van Walsum - Environmental Studies).
Escalating oil prices, reliance on foreign reserves, and environmental concerns over nonrenewable resources have sparked interest in alternative sources of energy. One rapidly emerging and practical fuel source is ethanol, which is easily produced from sugar and starch sources. However, ethanol from more fibrous plant material is still in the nascent stages of research, facing many challenges in enhancing the yield of sugars, especially glucose, from the cellulosic biomass. Pretreatment has been shown to greatly augment the efficacy of sugar conversion, thereby enhancing the fermentation process and overall ethanol productivity. One pretreatment method is sulfur dioxide-impregnation, but the facets of this catalyzed hydrolysis step are not fully understood as no thermodynamic predictions are available at high temperatures. In this experiment, room temperature predictions were analyzed and compared with the observed behavior of sulfur dioxide when used on samples of corn stover, a plausible source for future ethanol production. We tried to develop a means to accurately predict the pH of corn stover in the pretreatment step. To relate this to the pretreatment process, a variety of xylan solutions were tested in different reaction conditions to determine the nature of sulfur dioxde in relation to the values of sulfuric acid. A series of pretreatments was also conducted with corn stover. From these studies, it is possible to elucidate that sulfur dioxide-impregnation can be used as a substitute for the more commonly used sulfuric acid in the pretreatment stage of the biomass to ethanol process.
Gupta, Ekta. A Study of Retention Times in Gas Chromatography. ( Dr. Charles Garner - Chemistry).
Gas chromatography is a technique for analyzing and purifying small organic compounds. I have been using capillary GC columns, which are extremely long, narrow tubes made of fused silica, do not cause decomposition of compounds, and can withstand higher temperatures. Each capillary GC is equipped with a flame ionization detector that is sensitive to organic compounds and records a peak when the compound is detected. Using the split injection method and quickly applying my compounds to the column, I was able to obtain sharp peaks that gave me retention times (the number of minutes it takes the compound to pass through the GC). Starting at octane and eventually reaching tetracontane, a chain of 40 carbons, we recorded peaks for each alkane. By changing initial temperatures and increasing the temperature by five degrees every minute (ramp rate), we created a chart that may be used to save time and predict the retention time of compounds, especially if the users do not have any experience with the GC. Later, we ran compounds that had other atoms in them such as oxygen and nitrogen in order to calculate the carbon equivalent of these atoms, and we added the values to the chart. Therefore, by examining the behavior of a wide range of organic compounds, I hope the research I have done with it will benefit future chemists.