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- All Subjects: Chemistry
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Description
Applications of non-traditional stable isotope variations are moving beyond geosciences to biomedicine, made possible by advances in multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) technology. Mass-dependent isotope variation can provide information about the sources of elements and the chemical reactions that they undergo. Iron and calcium isotope systematics in biomedicine are relatively unexplored but have great potential scientific interest due to their essential nature in metabolism. Iron, a crucial element in biology, fractionates during biochemically relevant reactions. To test the extent of this fractionation in an important reaction process, equilibrium iron isotope fractionation during organic ligand exchange was determined. The results show that iron fractionates during organic ligand exchange, and that isotope enrichment increases as a function of the difference in binding constants between ligands. Additionally, to create a mass balance model for iron in a whole organism, iron isotope compositions in a whole mouse and in individual mouse organs were measured. The results indicate that fractionation occurs during transfer between individual organs, and that the whole organism was isotopically light compared with food. These two experiments advance our ability to interpret stable iron isotopes in biomedicine. Previous research demonstrated that calcium isotope variations in urine can be used as an indicator of changes in net bone mineral balance. In order to measure calcium isotopes by MC-ICP-MS, a chemical purification method was developed to quantitatively separate calcium from other elements in a biological matrix. Subsequently, this method was used to evaluate if calcium isotopes respond when organisms are subjected to conditions known to induce bone loss: 1) Rhesus monkeys were given an estrogen-suppressing drug; 2) Human patients underwent extended bed rest. In both studies, there were rapid, detectable changes in calcium isotope compositions from baseline - verifying that calcium isotopes can be used to rapidly detect changes in bone mineral balance. By characterizing iron isotope fractionation in biologically relevant processes and by demonstrating that calcium isotopes vary rapidly in response to bone loss, this thesis represents an important step in utilizing these isotope systems as a diagnostic and mechanistic tool to study the metabolism of these elements in vivo.
ContributorsMorgan, Jennifer Lynn Louden (Author) / Anbar, Ariel D. (Thesis advisor) / Wasylenki, Laura E. (Committee member) / Jones, Anne K. (Committee member) / Shock, Everett (Committee member) / Arizona State University (Publisher)
Created2011
Description
A new challenge on the horizon is to utilize the large amounts of protein found in the atmosphere to identify different organisms from which the protein originated. Included here is work investigating the presence of identifiable patterns of different proteins collected from the air and biological samples for the purposes of remote identification. Protein patterns were generated using high performance liquid chromatography (HPLC). Patterns created could identify high-traffic and low-traffic indoor spaces. Samples were collected from the air using air pumps to draw air through a filter paper trapping particulates, including large amounts of shed protein matter. In complimentary research aerosolized biological samples were collected from various ecosystems throughout Ecuador to explore the relationship between environmental setting and aerosolized protein concentrations. In order to further enhance protein separation and produce more detailed patterns for the identification of individual organisms of interest; a novel separation device was constructed and characterized. The separation device incorporates a longitudinal gradient as well as insulating dielectrophoretic features within a single channel. This design allows for the production of stronger local field gradients along a global gradient allowing particles to enter, initially transported through the channel by electrophoresis and electroosmosis, and to be isolated according to their characteristic physical properties, including charge, polarizability, deformability, surface charge mobility, dielectric features, and local capacitance. Thus, different types of particles are simultaneously separated at different points along the channel distance given small variations of properties. The device has shown the ability to separate analytes over a large dynamic range of size, from 20 nm to 1 μm, roughly the size of proteins to the size of cells. In the study of different sized sulfate capped polystyrene particles were shown to be selectively captured as well as concentrating particles from 103 to 106 times. Qualitative capture and manipulation of β-amyloid fibrils were also shown. The results demonstrate the selective focusing ability of the technique; and it may form the foundation for a versatile tool for separating complex mixtures. Combined this work shows promise for future identification of individual organisms from aerosolized protein as well as for applications in biomedical research.
ContributorsStaton, Sarah J. R (Author) / Hayes, Mark A. (Committee member) / Anbar, Ariel D (Committee member) / Shock, Everett (Committee member) / Williams, Peter (Committee member) / Arizona State University (Publisher)
Created2011
Description
Though schizophrenia was categorized as a mental illness over 100 years ago, there is a plethora of knowledge that continues to perplex the scientific and medical community alike. This tragic mental disorder affects approximately 1% of the general population, and many of these individuals are homeless if left untreated. Each schizophrenia patient has a different set of symptoms, so all of these patients experience a variety of positive and negative symptoms. Negative symptoms are called so as they are in absence, and some examples include apathy, anhedonia, lack of motivation, reduced social drive, and reduced cognitive functioning. Positive behavior, on the other hand, is a change in behavior or thoughts such as visual or auditory hallucinations, delusions, confused thoughts, disorganized speech, and trouble concentrating. Because schizophrenia patients do not share the exact same set of symptoms, research in schizophrenia requires a tremendous amount of medical resources. Over the last few years, new studies have started in the field of schizophrenia involving proteomics, or the study of proteins and their function. This new frontier gives doctors and scientists alike a new opportunity to improve the quality of life of schizophrenia patients by providing a potential method through which patients would receive individualized treatment based on their specific symptoms.
ContributorsPeterson, Rozabel (Author) / Brian, Jennifer (Thesis director) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Tempe Town Lake is the site of fifteen years’ worth of chemical data collection by ASU researchers. In 2018 the dataSONDE, an instrument capable of measuring different water quality parameters every thirty minutes for a month at a time was installed in the lake. The SONDE has the potential to completely reduce the need for sampling by hand. Before the SONDE becomes the sole means of gathering data, it is important to verify its accuracy. In this study, the measurements gathered by the SONDE (pH, dissolved oxygen, temperature, conductivity and colored dissolved organic matter) were compared to measurements gathered using the verified methods from the past fifteen years.
ContributorsSauer, Elinor Rayne (Author) / Hartnett, Hilairy (Thesis director) / Glaser, Donald (Committee member) / Shock, Everett (Committee member) / Historical, Philosophical & Religious Studies (Contributor) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
Enzyme Replacement Therapy (ERT) is a treatment often used for patients with disorders that affect the production of various enzymes within the body, such as Cystic Fibrosis and Fabry Disease. ERT involves the use of artificially-produced enzymes, which can be derived from humans, pigs, and bacteria. Generally, enzymes derived from porcine and bacterial sources are much less expensive and more accessible than those derived from a human source. This, and the ethical implications that porcine enzymes carry, make the decision of choosing treatment simple to some and complex to others. Ethically, human-derived enzymes are often considered more ethical, while not conflicting with religious beliefs and practices as porcine-derived enzymes do.
In order to further compare porcine and human-derived enzymes, a determination of the enzyme effectiveness was done via digestion simulation. The digestion for both the human and porcine-derived enzymes consisted of three steps: oral, gastric, and intestinal. After the digestion, the absorbance for each enzyme class as well as a dilution curve of the formula used was read and recorded. Using the standard dilution curve and the absorbance values for each unknown, the formula and thus enzyme concentration that was lost through the reaction was able to be calculated.
The effectiveness of both the human and porcine enzymes, determined by the percent of formula lost, was 18.2% and 19.7%, respectively, with an error of 0.6% from the spectrophotometer, and an error of about 10% from the scale used for measuring the enzymes. This error was likely due to the small mass required of the enzymes and can be prevented in the future by performing the experiment at a larger scale.
In order to further compare porcine and human-derived enzymes, a determination of the enzyme effectiveness was done via digestion simulation. The digestion for both the human and porcine-derived enzymes consisted of three steps: oral, gastric, and intestinal. After the digestion, the absorbance for each enzyme class as well as a dilution curve of the formula used was read and recorded. Using the standard dilution curve and the absorbance values for each unknown, the formula and thus enzyme concentration that was lost through the reaction was able to be calculated.
The effectiveness of both the human and porcine enzymes, determined by the percent of formula lost, was 18.2% and 19.7%, respectively, with an error of 0.6% from the spectrophotometer, and an error of about 10% from the scale used for measuring the enzymes. This error was likely due to the small mass required of the enzymes and can be prevented in the future by performing the experiment at a larger scale.
ContributorsBlevins, Brianna R (Author) / Martin, Thomas (Thesis director) / McILwraith, Heide (Committee member) / College of Integrative Sciences and Arts (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
As a child passes through the birth canal, they become inoculated with vital gram positive and gram-negative bacteria, aerobes and anaerobes. Breast milk helps to support this growing microbiome by providing oligosaccharides that support its proliferation. Breast milk can be considered the most nutritious source of food available to a growing infant by providing the necessary nutrients, growth hormones and antibodies to promote digestive health, growth, and a strong immune system. The Developmental Origins of Health and Disease Theory (DOHaD) is a theory that suggests a growing fetus and nursing child's nutrients and immune system are dependent on the mother's exposure to nutrients and toxins. Studies have shown a positive correlation between the length of nursing and a child's overall health through life. In addition, consuming an enriched diet after weaning builds a strong immunological and nutritional basis from which the child can grow. This leads to improvements in a child's overall health, which has beneficial long-term effects on morbidity and mortality. This project applied the theory to two Middle Horizon (AD500-1100) individuals from Akapana, Tiwanaku, in the Lake Titicaca Basin, Bolivia. Stable nitrogen and carbon isotope analysis was applied to first molar serial samples of these two individuals to determine weaning age and early childhood diet. Both individuals were male; one male died in adolescence between the age of 9-15 years, and the other died as an elderly adult around the age of 50-59 years. The results showed that the male who died in adulthood was provisioned with supplemental and post-weaning foods high in animal protein, and received breast milk until around 37 months of age. The adolescent male was weaned between 11-12 months and consumed a diet dominated by C4 plants \u2014 most likely maize \u2014 with much less protein. The correlation between prolonged access to breast milk and a healthier and more nutritious childhood diet and longevity are consistent with the theory discussed above.
ContributorsCampbell, Sibella Sweelin (Author) / Knudson, Kelly (Thesis director) / Marsteller, Sara (Committee member) / Greenwald, Alexandra (Committee member) / School of Human Evolution & Social Change (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Iron (Fe) scarcity limits biological productivity in high-nutrient low-chlorophyll (HNLC) ocean regions. Thus, the input, output and abundance of Fe in seawater likely played a critical role in shaping the development of modern marine ecosystems and perhaps even contributed to past changes in Earth’s climate. Three sources of Fe—wind-blown dust, hydrothermal activity, and sediment dissolution—carry distinct Fe isotopic fingerprints, and can therefore be used to track Fe source variability through time. However, establishing the timing of this source variability through Earth’s history remains challenging because the major depocenters for dissolved Fe in the ocean lack well-established chronologies. This is due to the fact that they are difficult to date with traditional techniques such as biostratigraphy and radiometric dating. Here, I develop age models for sediments collected from the International Drilling Program Expedition 329 by measuring the Os (osmium) isotopic composition of the hydrogenous portion of the clays. These extractions enable dating of the clays by aligning the Os isotope patterns observed in the clays to those in a reference curve with absolute age constraints through the Cenozoic. Our preliminary data enable future development of chronologies for three sediment cores from the high-latitude South Pacific and Southern Oceans, and demonstrate a wider utility of this method to establish age constraints on pelagic sediments worldwide. Moreover, the preliminary Os isotopic data provides a critical first step needed to examine the changes in Fe (iron) sources and cycling on millions of years timescales. Fe isotopic analysis was conducted at the same sites in the South Pacific and demonstrates that there are significant changes in the sources of Fe to the Southern Ocean over the last 90 Ma. These results lay the groundwork for the exploration of basin-scale sources to Fe source changes, which will have implications for understanding how biological productivity relates to Fe source variability over geological timescales.
ContributorsTegler, Logan Ashley (Author) / Anbar, Ariel (Thesis director) / Herckes, Pierre (Committee member) / Romaniello, Stephen (Committee member) / Department of English (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This study seeks to determine whether female and male students in general chemistry courses differ in exam and course-based performance. Using data from previous semesters of CHM 101 (Marks), CHM 101 (Bauer), CHM 114 (Seo, Windman), CHM 113/116 (Cabirac), and CHM 117/118 (Williams) courses taught at Arizona State University, the total exam scores and final course grades for each student were recorded and analyzed. The results of this study differ greatly by course type, as each course corresponded to a different STEM major. While CHM 113/116, the pre-medicinal majors course, saw evidence of stereotype threat via lower female exam performance, the other courses saw no statistical difference between male and female performance on their exam scores or overall course grades. For CHM 101, this was understandable, as the majority of students were nursing majors, who likely did not experience tokenism or feel stereotyped negatively in their science classes. However, CHM 114, the engineering majors course, and CHM 117/118, the research science course, saw parity with respect to male and female student performance. This suggests the possibility that female students face adversity in science and math courses before college that cause only those with high self-efficacy to advance to a career in these fields.
ContributorsWoner, Victoria Elaine (Author) / Gould, Ian (Thesis director) / Saenz, Delia (Committee member) / Austin, Ara (Committee member) / Department of Psychology (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The free-base tetra-tolyl-porphyrin and the corresponding cobalt and iron porphyrin complexes were synthesized and characterized to show that this class of compound can be promising, tunable catalysts for carbon dioxide reduction. During cyclic voltammetry experiments, the iron porphyrin showed an on-set of ‘catalytic current’ at an earlier potential than the cobalt porphyrin’s in organic solutions gassed with carbon dioxide. The cobalt porphyrin yielded larger catalytic currents, but at the same potential as the electrode. This difference, along with the significant changes in the porphyrin’s electronic, optical and redox properties, showed that its capabilities for carbon dioxide reduction can be controlled by metal ions, allotting it unique opportunities for applications in solar fuels catalysis and photochemical reactions.
ContributorsSkibo, Edward Kim (Author) / Moore, Gary (Thesis director) / Woodbury, Neal (Committee member) / School of Molecular Sciences (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Non-canonical amino acids (NCAAs) can be used in protein chemistry to determine their structures. A common method for imaging proteins is cryo-electron microscopy (cryo-EM) which is ideal for imaging proteins that cannot be obtained in large quantities. Proteins with indistinguishable features are difficult to image using this method due to the large size requirements, therefore antibodies designed specifically for binding these proteins have been utilized to better identify the proteins. By using an existing antibody that binds to stilbene, NCAAs containing this molecule can be used as a linker between proteins and an antibody. Stilbene containing amino acids can be integrated into proteins to make this process more access able. In this paper, synthesis methods for various NCAAs containing stilbene were proposed. The resulting successfully synthesized NCAAs were E)-N6-(5-oxo-5-((4-styrylphenyl) amino) pentanoyl) lysine, (R,E)-2-amino-3-(5-oxo-5-((4-styrylphenyl)amino)pentanamido)propanoic acid, (E)-2-amino-5-(5-oxo-5-((4-styrylphenyl) amino) pentanamido) pentanoic acid. A synthesis for three more shorter amino acids, (R,E)-2-amino-3-(3-oxo-3-((4-styrylphenyl) amino) propanamido) propanoic acid, (E)-2-amino-5-(3-oxo-3-((4-styrylphenyl) amino) propanamido) pentanoic acid, and (E)-N6-(3-oxo-3-((4-styrylphenyl) amino) propanoyl) lysine, is also proposed.
ContributorsJenkins, Bryll (Author) / Mills, Jeremy (Thesis director) / Ghirlanda, Giovanna (Committee member) / Nannenga, Brent (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor)
Created2022-05