Matching Items (277)
Description
With the development of technology, using photographs to measure plate waste is an increasing
trend. These photographs are later analyzed when the data is being entered into a form or
system. Previously, these forms or systems have not been assessed for usability. This research
study looks at three iterations of a digital plate waste observation system developed for the
School Lunch Study at Arizona State University. The System Usability Scale was used to
understand the functionality of the digital plate waste observation system. An area for free
responses was used to understand aspects of the system that were liked by research assistants
and what technical difficulties the research assistants encountered. These responses were used to
develop the next version of the digital plate waste observation system. Time to complete a task
was calculated to see the trends across all versions of the system. With each version, the System
Usability Scale scores increased along with the time to complete a task. This study found that
following the workflow of research assistants, being able to manipulate a photograph, having
menu items populated, and decreasing the amount of typing performed by adding selections to be
useful design aspects. Future digital plate waste observation systems can implement the
successful design aspects of this system, be aware of errors experienced, and implement helpful
features not found in this system. Future studies can look at the effect proctored training sessions
have on the time to complete a task and the relation of System Usability Scale scores with the
success of data entry.
trend. These photographs are later analyzed when the data is being entered into a form or
system. Previously, these forms or systems have not been assessed for usability. This research
study looks at three iterations of a digital plate waste observation system developed for the
School Lunch Study at Arizona State University. The System Usability Scale was used to
understand the functionality of the digital plate waste observation system. An area for free
responses was used to understand aspects of the system that were liked by research assistants
and what technical difficulties the research assistants encountered. These responses were used to
develop the next version of the digital plate waste observation system. Time to complete a task
was calculated to see the trends across all versions of the system. With each version, the System
Usability Scale scores increased along with the time to complete a task. This study found that
following the workflow of research assistants, being able to manipulate a photograph, having
menu items populated, and decreasing the amount of typing performed by adding selections to be
useful design aspects. Future digital plate waste observation systems can implement the
successful design aspects of this system, be aware of errors experienced, and implement helpful
features not found in this system. Future studies can look at the effect proctored training sessions
have on the time to complete a task and the relation of System Usability Scale scores with the
success of data entry.
ContributorsStott, Dahlia (Author) / Adams, Marc (Thesis director) / Barto, Henry (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
Description
The rise in community-associated methicillin-resistant Staphylococcus aureus (MRSA) infections and the ability of the organism to develop resistance to antibiotics necessitate new treatment methods for MRSA. Geopolymers (GPs) are cheap, porous materials that have demonstrated adsorptive capabilities. In this study, GPs were investigated for their ability to adsorb whole MRSA cells and MRSA secreted proteins [culture filtrate proteins (CFPs)] as a complementary method of controlling MRSA infections. GPs have been synthesized with variable pore sizes (meso/macro scale) and further modified with stearic acid (SA) to increase surface hydrophobicity. Four GPs (SA-macroGP, macroGP, SA-mesoGP, and mesoGP) were incubated with whole cells and with CFPs to quantify GP adsorption capabilities. Following MRSA culture incubation with GPs, unbound MRSA cells were filtered and plated to determine cell counts. Following CFP incubation with GPs, unbound CFPs were separated via SDS-PAGE, stained with SYPRO Ruby, and analyzed using densitometry. Results indicate that macroGP was the most effective at adsorbing whole MRSA cells. Visual banding patterns and densitometry quantitation indicate that SA-mesoGP was the most effective at adsorbing CFP. Ultimately, GP-based products may be further developed as nonselective or selective adsorbents and integrated into fibrous materials for topical applications.
ContributorsGanser, Collin (Co-author, Co-author) / Haydel, Shelley E. (Thesis director) / Seo, Don (Committee member) / Borges, Chad (Committee member) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
White-nose syndrome (WNS) is a fungal infection devastating bat populations throughout eastern North America. WNS is caused by a fungus, Pseudogymnoascus destructans (Pd), that invades the skin of hibernating bats. While there are a number of treatments being researched, there is currently no effective treatment for WNS that is deployed in the field, except a few being tested on a limited scale. Bats have lowered immune function and response during hibernation, which may increase susceptibility to infection during the winter months. Antimicrobial peptides (AMPs) are a crucial component of the innate immune system and serve as barriers against infection. AMPs are constitutively expressed on skin and facilitate wound healing, stimulate other immune responses, and may also stay active on bat skin during hibernation. AMPs are expressed by all tissues, have direct killing abilities against microbes, and are a potential treatment for bats infected with Pd. In this investigation, the fungicidal activity of several readily available commercial AMPs were compared, and killing assay protocols previously investigated by Frasier and Lake were replicated to establish a control trial for use in future killing assays. Another aim of this investigation was to synthesize a bat-derived AMP for use in the killing assay. Sequences of bat-derived AMPs have been identified in bat skin samples obtained from a large geographic sampling of susceptible and resistant species. Contact was made with GenScript Inc., the company from which commercially available AMPs were purchased, to determine the characteristics of peptide sequences needed to synthesize an AMP for lab use. Based on recommendations from GenScript Inc., peptide sequences need to have a hydrophobicity of less than 50% and a sequence length of less than 50 amino acids. These criteria serve as a potential barrier because none of the known bat-derived sequences analyzed satisfy both of these requirements. The final aim of this study was to generate a conceptual model of the immune response molecules activated when bats are exposed to a fungal pathogen such as Pd. Overall, this work investigated sources of variability between trials of the killing assay, analyzed known bat-derived peptide sequences, and generated a conceptual model that will serve as a guideline for identification of immune response molecules on the skin of bats in future proteomics work.
ContributorsBarton, Madisen L (Author) / Moore, Marianne (Thesis director) / Penton, Christopher (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The purpose of this thesis creative project was to create an educational video to present research findings on the increasingly important issue of human biospecimen preanalytic variables. When a human biospecimen, such as blood, urine, or tissue, is removed from the body, it is subjected to a plethora of variables that are not recorded or regulated in a vast majority of cases. Frequently, these samples arrive at the research or pathology lab with an unknown history, then undergo analysis for translational research purposes, or to guide clinical management decisions. Thus, compromised specimen quality caused by preanalytic variables has substantial, and potentially devastating, downstream effects. To identify the preanalytic variables with the greatest impact on blood and tissue specimen quality, 45 articles were gathered using PubMed and Google Scholar databases and cited. Based on the articles, the top five variables with the most detrimental effects were identified for both blood and tissue samples. Multiple sets of parameters ensuring specimen fitness were compared for each of the five variables for each specimen type. Then, specific parameters guaranteeing the fitness of the greatest number of analytes were verified. To present the research findings in greater detail, a paper was written that focused on identifying the top variables and key parameters to ensure analyte fitness. To present the overall issue in an easy-to-digest format, a storyboard and script were created as a guideline for a final video project. Ultimately, two alternate versions of the video were created to pertain to the audience of choice (one version for patients, one version for professionals). It is the hope that these videos will be used as educational tools to continue efforts to standardize and enforce human biospecimen preanalytic variable parameters. This is a necessary step to improve the accuracy of our biomedical research data and the healthcare of patients worldwide.
ContributorsAzcarate, Heather (Author) / Compton, Carolyn (Thesis director) / LaBaer, Joshua (Committee member) / Borges, Chad (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2018-12
Description
While non-invasive breast cancer treatments may be considered less costly in the short-term, over the course of a lifetime, a more aggressive treatment can be overall less costly, especially with recurrence cases; however, these more aggressive treatments are not necessarily covered by insurance and are difficult to discuss in the short amount of time in physician consultations. This analysis studied data from 982 women diagnosed with breast cancer over a five-year period to evaluate monetary costs associated with treatment options and incorporated five in-depth interviews to understand experiences and non-monetary costs. Data showed the most expensive option was a unilateral mastectomy with radiation therapy and the least costly option was breast conserving surgery. Interviews determined each woman evaluated the monetary costs with each treatment but most heavily focused on personal values, biases and recommended opinions when deciding on a treatment. The use of prompt sheets before physician appointments and consultations, along with the addition of financial counselor meeting with each patient can improve patient satisfaction and alleviate stress by simplifying a woman's choice in deciding a treatment. In addition, increased insurance coverage to include every treatment chosen by women (rather than on a case-by-case basis), specifically contralateral prophylactic mastectomy and additional screening options, could decrease long term costs \u2014 both monetarily and in quality of life for patients.
ContributorsOsumi, Alana (Author) / LaRosa, Julia (Thesis director) / Sivanantham, Jai (Committee member) / Barrett, The Honors College (Contributor) / W.P. Carey School of Business (Contributor)
Created2018-12
Description
The objective of this study was to evaluate and compare the content of nutrition marketing materials within the cafeterias of schools in Central Arizona. By collecting photographs of marketing material from three elementary schools, one K-8 school, three middle schools and three high schools, 59 pieces of nutrition marketing were gathered. The schools chosen were a convenience sample and selected from schools that were already participating in ASU' s School Lunch Study. The photographs were sorted by grade level and then coded quantitatively and qualitatively for their purpose, visual components, strategies used and relevance. Results from this novel study provided insight into prevalence, size, textual content, educational content, strategies for fruit and vegetable marketing, messaging and overall design of existing nutrition marketing within the sample schools. This study found that the prevalence of nutrition marketing within all school cafeterias appeared to be low, particularly within elementary and middle schools. Diverse types of messaging were present among elementary, middle and high schools and a variety of appeals were utilized with little consistency. Many of the strategies used in the nutrition marketing appeared disconnected from the population it was intended to appeal to. Educational components were notably lacking within middle school cafeterias but were often effectively integrated into high school nutrition marketing. The results are unique to this population, and further research is required to evaluate the content of existing nutrition material on a larger scale, so efforts can be made to improve the persuasiveness of nutrition marketing in promoting fruit and vegetable consumption.
ContributorsXavier, Raevyn Francine (Author) / Bruening, Meg (Thesis director) / Adams, Marc (Committee member) / School of Nutrition and Health Promotion (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Background
African American women report insufficient physical activity and are disproportionally burdened by associated disease conditions; indicating the need for innovative approaches to promote physical activity in this underserved population. Social media platforms (i.e. Facebook) and text messaging represent potential mediums to promote physical activity. This paper reports the results of a randomized pilot trial evaluating a theory-based (Social Cognitive Theory) multi-component intervention using Facebook and text-messages to promote physical activity among African American women.
Methods
Participants (N = 29) were randomly assigned to receive one of two multi-component physical activity interventions over 8 weeks: a culturally-relevant, Social Cognitive Theory-based, intervention delivered by Facebook and text message (FI) (n = 14), or a non-culturally tailored print-based intervention (PI) (n = 15) consisting of promotion brochures mailed to their home. The primary outcome of physical activity was assessed by ActiGraph GT3X+ accelerometers. Secondary outcomes included self-reported physical activity, physical activity-related psychosocial variables, and participant satisfaction.
Results
All randomized participants (N = 29) completed the study. Accelerometer measured physical activity showed that FI participants decreased sedentary time (FI = −74 minutes/week vs. PI = +118 minute/week) and increased light intensity (FI = +95 minutes/week vs. PI = +59 minutes/week) and moderate-lifestyle intensity physical activity (FI = + 27 minutes/week vs. PI = −34 minutes/week) in comparison to PI participants (all P’s < .05). No between group differences for accelerometer measured moderate-to-vigorous intensity physical activity were observed (P > .05). Results of secondary outcomes showed that in comparison to the PI, FI participants self-reported greater increases in moderate-to-vigorous physical activity (FI = +62 minutes/week vs. PI = +6 minutes/week; P = .015) and had greater enhancements in self-regulation for physical activity (P < .001) and social support from family for physical activity (P = .044). Satisfaction with the FI was also high: 100% reported physical activity-related knowledge gains and 100% would recommend the program to a friend.
Conclusions
A culturally-relevant Facebook and text message delivered physical activity program was associated with several positive outcomes, including decreased sedentary behavior, increased light- and moderate-lifestyle intensity physical activity, enhanced psychosocial outcomes, and high participant satisfaction. Future studies with larger samples are warranted to further explore the efficacy of technology-based approaches to promote physical activity among African American women.
African American women report insufficient physical activity and are disproportionally burdened by associated disease conditions; indicating the need for innovative approaches to promote physical activity in this underserved population. Social media platforms (i.e. Facebook) and text messaging represent potential mediums to promote physical activity. This paper reports the results of a randomized pilot trial evaluating a theory-based (Social Cognitive Theory) multi-component intervention using Facebook and text-messages to promote physical activity among African American women.
Methods
Participants (N = 29) were randomly assigned to receive one of two multi-component physical activity interventions over 8 weeks: a culturally-relevant, Social Cognitive Theory-based, intervention delivered by Facebook and text message (FI) (n = 14), or a non-culturally tailored print-based intervention (PI) (n = 15) consisting of promotion brochures mailed to their home. The primary outcome of physical activity was assessed by ActiGraph GT3X+ accelerometers. Secondary outcomes included self-reported physical activity, physical activity-related psychosocial variables, and participant satisfaction.
Results
All randomized participants (N = 29) completed the study. Accelerometer measured physical activity showed that FI participants decreased sedentary time (FI = −74 minutes/week vs. PI = +118 minute/week) and increased light intensity (FI = +95 minutes/week vs. PI = +59 minutes/week) and moderate-lifestyle intensity physical activity (FI = + 27 minutes/week vs. PI = −34 minutes/week) in comparison to PI participants (all P’s < .05). No between group differences for accelerometer measured moderate-to-vigorous intensity physical activity were observed (P > .05). Results of secondary outcomes showed that in comparison to the PI, FI participants self-reported greater increases in moderate-to-vigorous physical activity (FI = +62 minutes/week vs. PI = +6 minutes/week; P = .015) and had greater enhancements in self-regulation for physical activity (P < .001) and social support from family for physical activity (P = .044). Satisfaction with the FI was also high: 100% reported physical activity-related knowledge gains and 100% would recommend the program to a friend.
Conclusions
A culturally-relevant Facebook and text message delivered physical activity program was associated with several positive outcomes, including decreased sedentary behavior, increased light- and moderate-lifestyle intensity physical activity, enhanced psychosocial outcomes, and high participant satisfaction. Future studies with larger samples are warranted to further explore the efficacy of technology-based approaches to promote physical activity among African American women.
ContributorsJoseph, Rodney (Author) / Keller, Colleen (Author) / Adams, Marc (Author) / Ainsworth, Barbara (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor)
Created2015-03-27
Description
Background
Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country.
Methods
Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported.
Results
Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries.
Conclusion
There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries.
Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country.
Methods
Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported.
Results
Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries.
Conclusion
There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries.
ContributorsDing, Ding (Author) / Adams, Marc (Author) / Sallis, James F. (Author) / Norman, Gregory J. (Author) / Hovell, Melbourn F. (Author) / Chambers, Christina D. (Author) / Hofstetter, C. Richard (Author) / Bowles, Heather R. (Author) / Hagstromer, Maria (Author) / Craig, Cora L. (Author) / Fernando Gomez, Luis (Author) / De Bourdeaudhuij, Ilse (Author) / Macfarlane, Duncan J. (Author) / Ainsworth, Barbara (Author) / Bergman, Patrick (Author) / Bull, Fiona C. (Author) / Carr, Harriette (Author) / Klasson-Heggebo, Lena (Author) / Inoue, Shigeru (Author) / Murase, Norio (Author) / Matsudo, Sandra (Author) / Matsudo, Victor (Author) / McLean, Grant (Author) / Sjostrom, Michael (Author) / Tomten, Heidi (Author) / Lefevre, Johan (Author) / Volbekiene, Vida (Author) / Bauman, Adrian E. (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-05-14
Description
Background
Neighborhood environment studies of physical activity (PA) have been mainly single-country focused. The International Prevalence Study (IPS) presented a rare opportunity to examine neighborhood features across countries. The purpose of this analysis was to: 1) detect international neighborhood typologies based on participants’ response patterns to an environment survey and 2) to estimate associations between neighborhood environment patterns and PA.
Methods
A Latent Class Analysis (LCA) was conducted on pooled IPS adults (N=11,541) aged 18 to 64 years old (mean=37.5 ±12.8 yrs; 55.6% women) from 11 countries including Belgium, Brazil, Canada, Colombia, Hong Kong, Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S. This subset used the Physical Activity Neighborhood Environment Survey (PANES) that briefly assessed 7 attributes within 10–15 minutes walk of participants’ residences, including residential density, access to shops/services, recreational facilities, public transit facilities, presence of sidewalks and bike paths, and personal safety. LCA derived meaningful subgroups from participants’ response patterns to PANES items, and participants were assigned to neighborhood types. The validated short-form International Physical Activity Questionnaire (IPAQ) measured likelihood of meeting the 150 minutes/week PA guideline. To validate derived classes, meeting the guideline either by walking or total PA was regressed on neighborhood types using a weighted generalized linear regression model, adjusting for gender, age and country.
Results
A 5-subgroup solution fitted the dataset and was interpretable. Neighborhood types were labeled, “Overall Activity Supportive (52% of sample)”, “High Walkable and Unsafe with Few Recreation Facilities (16%)”, “Safe with Active Transport Facilities (12%)”, “Transit and Shops Dense with Few Amenities (15%)”, and “Safe but Activity Unsupportive (5%)”. Country representation differed by type (e.g., U.S. disproportionally represented “Safe but Activity Unsupportive”). Compared to the Safe but Activity Unsupportive, two types showed greater odds of meeting PA guideline for walking outcome (High Walkable and Unsafe with Few Recreation Facilities, OR= 2.26 (95% CI 1.18-4.31); Overall Activity Supportive, OR= 1.90 (95% CI 1.13-3.21). Significant but smaller odds ratios were also found for total PA.
Conclusions
Meaningful neighborhood patterns generalized across countries and explained practical differences in PA. These observational results support WHO/UN recommendations for programs and policies targeted to improve features of the neighborhood environment for PA.
Neighborhood environment studies of physical activity (PA) have been mainly single-country focused. The International Prevalence Study (IPS) presented a rare opportunity to examine neighborhood features across countries. The purpose of this analysis was to: 1) detect international neighborhood typologies based on participants’ response patterns to an environment survey and 2) to estimate associations between neighborhood environment patterns and PA.
Methods
A Latent Class Analysis (LCA) was conducted on pooled IPS adults (N=11,541) aged 18 to 64 years old (mean=37.5 ±12.8 yrs; 55.6% women) from 11 countries including Belgium, Brazil, Canada, Colombia, Hong Kong, Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S. This subset used the Physical Activity Neighborhood Environment Survey (PANES) that briefly assessed 7 attributes within 10–15 minutes walk of participants’ residences, including residential density, access to shops/services, recreational facilities, public transit facilities, presence of sidewalks and bike paths, and personal safety. LCA derived meaningful subgroups from participants’ response patterns to PANES items, and participants were assigned to neighborhood types. The validated short-form International Physical Activity Questionnaire (IPAQ) measured likelihood of meeting the 150 minutes/week PA guideline. To validate derived classes, meeting the guideline either by walking or total PA was regressed on neighborhood types using a weighted generalized linear regression model, adjusting for gender, age and country.
Results
A 5-subgroup solution fitted the dataset and was interpretable. Neighborhood types were labeled, “Overall Activity Supportive (52% of sample)”, “High Walkable and Unsafe with Few Recreation Facilities (16%)”, “Safe with Active Transport Facilities (12%)”, “Transit and Shops Dense with Few Amenities (15%)”, and “Safe but Activity Unsupportive (5%)”. Country representation differed by type (e.g., U.S. disproportionally represented “Safe but Activity Unsupportive”). Compared to the Safe but Activity Unsupportive, two types showed greater odds of meeting PA guideline for walking outcome (High Walkable and Unsafe with Few Recreation Facilities, OR= 2.26 (95% CI 1.18-4.31); Overall Activity Supportive, OR= 1.90 (95% CI 1.13-3.21). Significant but smaller odds ratios were also found for total PA.
Conclusions
Meaningful neighborhood patterns generalized across countries and explained practical differences in PA. These observational results support WHO/UN recommendations for programs and policies targeted to improve features of the neighborhood environment for PA.
ContributorsAdams, Marc (Author) / Ding, Ding (Author) / Sallis, James F. (Author) / Bowles, Heather R. (Author) / Ainsworth, Barbara (Author) / Bergman, Patrick (Author) / Bull, Fiona C. (Author) / Carr, Harriette (Author) / Craig, Cora L. (Author) / De Bourdeaudhuij, Ilse (Author) / Fernando Gomez, Luis (Author) / Hagstromer, Maria (Author) / Klasson-Heggebo, Lena (Author) / Inoue, Shigeru (Author) / Lefevre, Johan (Author) / Macfarlane, Duncan J. (Author) / Matsudo, Sandra (Author) / Matsudo, Victor (Author) / McLean, Grant (Author) / Murase, Norio (Author) / Sjostrom, Michael (Author) / Tomten, Heidi (Author) / Volbekiene, Vida (Author) / Bauman, Adrian (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-03-07
Description
In the development of personalized medicine and many other clinical studies, biospecimen integrity serves as the prerequisite for not only the accurate derivation of patient- and disease-specific molecular data from biological specimens but the meaningful downstream validation of biomarkers. However, a large number of preanalytical variables may influence the quality of biospecimens in an undesired way and ultimately render the samples unsuitable for molecular analysis. The limited ability to directly reduce discrepancies caused by preanalytical variables gives rise to the need for development and retrospective application of appropriate tests for assessment of biospecimen integrity. Nevertheless, the most standard approaches to assessing biospecimen integrity involve nontrivial procedures. Thus, the need for quality control tools or tests that are readily applicable and can produce results in a straightforward way becomes critical. As one of the major ex vivo biomolecular degradation mechanisms, oxidation that occurs when blood plasma and serum samples are exposed to thawed states during storage and processing is hard to forestall and detect. In an attempt to easily detect and monitor the degree of oxidation, the technique of Fluorescence Resonance Energy Transfer (FRET) was examined to determine whether this concept could be employed to monitor exposure of samples to thawed conditions when controlled by spontaneous oxidative disulfide bonding. The intended mode of usage was envisioned as a fluorescence liquid being stored in a separate compartment but within the same test tube as archived plasma and serum samples. This would allow the assessment of sample integrity by direct visualization of fluorescence under a hand-held black light. The fluorescent dynamic range as well as kinetic control of the reaction were studied. While the addition of Cu(II) proved to facilitate excellent dynamic range with regard to fluorescence quenching, the kinetics of the reaction were too rapid for practical use. Further investigation revealed that the fluorescence quenching mechanism might have actually occurred via Intramolecular Charge Transfer (ICT) rather than FRET mediated by oxidative disulfide bond formation. Introduction of Cu(II) via copper metal slowed fluorescence quenching to the point of practical utility; facilitating demonstration that storing at room temperature, refrigerating or freezing the samples delayed fluorescence quenching to different extents. To establish better kinetic control, future works will focus on establishing controlled, thoroughly understood kinetic release of Cu(II) from copper metal.
ContributorsZhang, Zihan (Author) / Borges, Chad (Thesis director) / Emady, Heather (Committee member) / Williams, Peter (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12