Matching Items (21)
Filtering by
- All Subjects: Chemistry
- All Subjects: healthcare
- Creators: School of Molecular Sciences
- Member of: Theses and Dissertations
- Resource Type: Text
Description
Increasing concentrations of carbon dioxide in the atmosphere will inevitably lead to long-term changes in climate that can have serious consequences. Controlling anthropogenic emission of carbon dioxide into the atmosphere, however, represents a significant technological challenge. Various chemical approaches have been suggested, perhaps the most promising of these is based on electrochemical trapping of carbon dioxide using pyridine and derivatives. Optimization of this process requires a detailed understanding of the mechanisms of the reactions of reduced pyridines with carbon dioxide, which are not currently well known. This thesis describes a detailed mechanistic study of the nucleophilic and Bronsted basic properties of the radical anion of bipyridine as a model pyridine derivative, formed by one-electron reduction, with particular emphasis on the reactions with carbon dioxide. A time-resolved spectroscopic method was used to characterize the key intermediates and determine the kinetics of the reactions of the radical anion and its protonated radical form. Using a pulsed nanosecond laser, the bipyridine radical anion could be generated in-situ in less than 100 ns, which allows fast reactions to be monitored in real time. The bipyridine radical anion was found to be a very powerful one-electron donor, Bronsted base and nucleophile. It reacts by addition to the C=O bonds of ketones with a bimolecular rate constant around 1* 107 M-1 s-1. These are among the fastest nucleophilic additions that have been reported in literature. Temperature dependence studies demonstrate very low activation energies and large Arrhenius pre-exponential parameters, consistent with very high reactivity. The kinetics of E2 elimination, where the radical anion acts as a base, and SN2 substitution, where the radical anion acts as a nucleophile, are also characterized by large bimolecular rate constants in the range ca. 106 - 107 M-1 s-1. The pKa of the bipyridine radical anion was measured using a kinetic method and analysis of the data using a Marcus theory model for proton transfer. The bipyridine radical anion is found to have a pKa of 40±5 in DMSO. The reorganization energy for the proton transfer reaction was found to be 70±5 kJ/mol. The bipyridine radical anion was found to react very rapidly with carbon dioxide, with a bimolecular rate constant of 1* 108 M-1 s-1 and a small activation energy, whereas the protonated radical reacted with carbon dioxide with a rate constant that was too small to measure. The kinetic and thermodynamic data obtained in this work can be used to understand the mechanisms of the reactions of pyridines with carbon dioxide under reducing conditions.
ContributorsRanjan, Rajeev (Author) / Gould, Ian R (Thesis advisor) / Buttry, Daniel A (Thesis advisor) / Yarger, Jeff (Committee member) / Seo, Dong-Kyun (Committee member) / Arizona State University (Publisher)
Created2015
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
This study investigates how the patient-provider relationship between lesbian, gay, and bisexual women and their healthcare providers influences their access to, utilization of, and experiences within healthcare environments. Nineteen participants, ages 18 to 34, were recruited using convenience and snowball sampling. Interviews were conducted inquiring about their health history and their experiences within the healthcare system in the context of their sexual orientation. The data collected from these interviews was used to create an analysis of the healthcare experiences of those who identify as queer. Although the original intention of the project was to chronicle the experiences of LGB women specifically, there were four non-binary gender respondents who contributed interviews. In an effort to not privilege any orientation over another, the respondents were collectively referred to as queer, given the inclusive and an encompassing nature of the term. The general conclusion of this study is that respondents most often experienced heterosexism rather than outright homophobia when accessing healthcare. If heterosexism was present within the healthcare setting, it made respondents feel uncomfortable with their providers and less likely to inform them of their sexuality even if it was medically relevant to their health outcomes. Gender, race, and,socioeconomic differences also had an effect on the patient-provider relationship. Non-binary respondents acknowledged the need for inclusion of more gender options outside of male or female on the reporting forms often seen in medical offices. By doing so, medical professionals are acknowledging their awareness and knowledge of people outside of the binary gender system, thus improving the experience of these patients. While race and socioeconomic status were less relevant to the context of this study, it was found that these factors have an affect on the patient-provider relationship. There are many suggestions for providers to improve the experiences of queer patients within the healthcare setting. This includes nonverbal indications of acknowledgement and acceptance, such as signs in the office that indicate it to be a queer friendly space. This will help in eliminating the fear and miscommunication that can often happen when a queer patient sees a practitioner for the first time. In addition, better education on medically relevant topics to queer patients, is necessary in order to eliminate disparities in health outcomes. This is particularly evident in trans health, where specialized education is necessary in order to decrease poor health outcomes in trans patients. Future directions of this study necessitate a closer look on how race and socioeconomic status have an effect on a queer patient's relationship with their provider.
ContributorsRajan, Sindhu (Co-author) / Bradley, Arianna (Co-author) / Larson, Michelle (Co-author) / Alvarado, Aimee (Co-author) / Ingram-Waters, Mary (Thesis director) / Arnold, Michelle (Committee member) / School of Molecular Sciences (Contributor) / School of Social Transformation (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / College of Public Service and Community Solutions (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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
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
This research will focus on identifying healthcare disparities among different groups of people in Maricopa County, with a focus on the Phoenix area. It takes form in a combination of a review of previously existing data, surveying pregnant women about their health insurance situations before their pregnancies, and surveying college students in Maricopa County about their past and current health insurance situations. The pregnant women who were interview were part of a study called Metabolism Tracking During Pregnancy through the School of Nutrition and Health Promotion at Arizona State University. College students who were interviewed were recruited online and all participants were choosing to respond. This research paper will focus on policies currently in place to try to address healthcare disparities and establishing the presence of healthcare disparities that are preexisting, and using individual responses from a small sample size of minorities and women to represent the larger Phoenix population. Differences in healthcare spending for different groups of people will also be analyzed in order to establish disparities present. This research is significant because if healthcare equality is the goal, then spending distribution to each should be proportional to the size of each subpopulation.
ContributorsGeiser, Rachel (Author) / Reifsnider, Elizabeth (Thesis director) / Cortese, Denis (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this project is to develop a risk assessment tool for the University of California, Riverside (UCR). UCR is health enterprise that manages operations under an environment of innate and uncontrollable risks. Therefore, a risk assessment tool is highly advisable under California State Laws and federal laws. In the case of overlapping laws, federal law will always prevail unless State law explicitly states otherwise. California Health Information Privacy Manual states that California must follow numerous state guidelines and a federal set of guidelines called HIPAA (Health Insurance Portability and Accountability Act of 1996). HIPAA is put in place to protect and serve as an organizational tool to develop a stronger and more secure infrastructure of security measures within healthcare enterprises. Under HIPAA is a Security and Privacy Rule that was implemented by The U.S. Department of Health and Human Services (HHS) and will serve as the basis for the risk assessment tool I developed. The Security and Privacy Rule's main goal is to set a national standard of how electronic protected health information (ePHI) will be appropriately used and disclosed by organizations subject to this rule, also known covered entities. Covered entities include health plans, health care providers and health care clearinghouses unless specifically stated otherwise. Permitted uses and disclosures of PHI or ePHI are outlined in detail and covered entities are expected to follow all aspects of it that pertain to their role within a healthcare system. Under HHS, the Office of Civil Rights (OCR) strictly enforces the Security and Privacy Rules and can issue civil money penalties and/or other major consequences making this a sizable and critical issue in healthcare environments. Each risk and impact must be assessed to determine an overall risk score. This score will then determine what risks need to be immediately addressed and which risks are most critical to UCR. To do this, potential impacts were determined for each section. The impact score can be decided by using a chart that will be discussed in the development section. The likeliness of the risk can be determined by a UCR professional via the provided chart and an overall risk score can be assigned. From here, an action plan can be set and carried out to eliminate possible hazards and imminent risks. Once a Risk Assessment tool is developed, potential risks can be indentified and dealt with appropriately in regard to level of impact and the likelihood of the risk occurring. By reducing risk, a healthcare enterprise can gain greater financial stability, decrease loss and protect vital information that is critical to the success organization.
ContributorsAustin, Hannah N. (Author) / Riley, William (Thesis director) / Hackman, Paul (Committee member) / School of Molecular Sciences (Contributor) / W.P. Carey School of Business (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 two chapters of this thesis focus on different aspects of DNA and the properties of nucleic acids as the whole. Chapter 1 focuses on the structure of DNA and its relationship to enzymatic efficiency. Chapter 2 centers itself on threose nucleic acid and optimization of a step in the path to its synthesis. While Chapter 1 discusses DNA and Uracil-DNA Glycosylase with regards to the base excision repair pathway, Chapter 2 focuses on chemical synthesis of an intermediate in the pathway to the synthesis of TNA, an analogous structure with a different saccharide in the sugar-phosphate backbone.
Chapter 1 covers the research under Dr. Levitus. Four oligonucleotides were reacted for zero, five, and thirty minutes with uracil-DNA glycosylase and subsequent addition of piperidine. These oligonucleotides were chosen based on their torsional rigidities as predicted by past research and predictions. The objective was to better understand the relationship between the sequence of DNA surrounding the incorrect base and the enzyme’s ability to remove said base in order to prepare the DNA for the next step of the base excision repair pathway. The first pair of oligonucleotides showed no statistically significant difference in enzymatic efficiency with p values of 0.24 and 0.42, while the second pair had a p value of 0.01 at the five-minute reaction. The second pair is currently being researched at different reaction times to determine at what point the enzyme seems to equilibrate and react semi-equally with all sequences of DNA.
Chapter 2 covers the research conducted under Dr. Chaput. Along the TNA synthesis pathway, the nitrogenous base must be added to the threofuranose sugar. The objective was to optimize the original protocol of Vorbrüggen glycosylation and determine if there were better conditions for the synthesis of the preferred regioisomer. This research showed that toluene and ortho-xylene were more preferable as solvents than the original anhydrous acetonitrile, as the amount of preferred isomer product far outweighed the amount of side product formed, as well as improving total yield overall. The anhydrous acetonitrile reaction had a final yield of 60.61% while the ortho-xylene system had a final yield of 94.66%, an increase of approximately 32%. The crude ratio of preferred isomer to side product was also improved, as it went from 18% undesired in anhydrous acetonitrile to 4% undesired in ortho-xylene, both values normalized to the preferred regioisomer.
Chapter 1 covers the research under Dr. Levitus. Four oligonucleotides were reacted for zero, five, and thirty minutes with uracil-DNA glycosylase and subsequent addition of piperidine. These oligonucleotides were chosen based on their torsional rigidities as predicted by past research and predictions. The objective was to better understand the relationship between the sequence of DNA surrounding the incorrect base and the enzyme’s ability to remove said base in order to prepare the DNA for the next step of the base excision repair pathway. The first pair of oligonucleotides showed no statistically significant difference in enzymatic efficiency with p values of 0.24 and 0.42, while the second pair had a p value of 0.01 at the five-minute reaction. The second pair is currently being researched at different reaction times to determine at what point the enzyme seems to equilibrate and react semi-equally with all sequences of DNA.
Chapter 2 covers the research conducted under Dr. Chaput. Along the TNA synthesis pathway, the nitrogenous base must be added to the threofuranose sugar. The objective was to optimize the original protocol of Vorbrüggen glycosylation and determine if there were better conditions for the synthesis of the preferred regioisomer. This research showed that toluene and ortho-xylene were more preferable as solvents than the original anhydrous acetonitrile, as the amount of preferred isomer product far outweighed the amount of side product formed, as well as improving total yield overall. The anhydrous acetonitrile reaction had a final yield of 60.61% while the ortho-xylene system had a final yield of 94.66%, an increase of approximately 32%. The crude ratio of preferred isomer to side product was also improved, as it went from 18% undesired in anhydrous acetonitrile to 4% undesired in ortho-xylene, both values normalized to the preferred regioisomer.
ContributorsTamirisa, Ritika Sai (Author) / Levitus, Marcia (Thesis director) / Stephanopoulos, Nicholas (Committee member) / Windman, Todd (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Circular Dichroism (CD) and electron paramagnetic resonance (EPR) were used to investigate the metal-binding sites of five different four-helix bundles, which have slight differences in the population of their side chains. Of the four-helix bundles, three have central dinuclear metal binding sites; two of these three also have outer dinuclear metal binding sites. The other two peptides have two identical, non-central, dinuclear metal binding sites. The CD spectra showed changes in the secondary structure of the peptides, and X-band EPR spectra of these peptides revealed the unique four peak signal of Cu(II). These findings improve our understanding of the metal binding environments of these peptides.
ContributorsCanarie, Elizabeth Rose (Author) / Allen, James (Thesis director) / Wolf, George (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05