Matching Items (14)
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- All Subjects: electrochemistry
- Creators: Harrington Bioengineering Program
Description
An increasing number of military veterans are enrolling in college, primarily due to the Post-9/11 GI Bill, which provides educational benefits to veterans who served on active duty since September 11, 2001. With rigorous training, active combat situations, and exposure to unexpected situations, the veteran population is at a higher risk for traumatic brain injury (TBI), Post Traumatic Stress Disorder (PTSD), and depression. All of these conditions are associated with cognitive consequences, including attention deficits, working memory problems, and episodic memory impairments. Some conditions, particularly mild TBI, are not diagnosed or treated until long after the injury when the person realizes they have cognitive difficulties. Even mild cognitive problems can hinder learning in an academic setting, but there is little data on the frequency and severity of cognitive deficits in veteran college students. The current study examines self-reported cognitive symptoms in veteran students compared to civilian students and how those symptoms relate to service-related conditions. A better understanding of the pattern of self-reported symptoms will help researchers and clinicians determine the veterans who are at higher risk for cognitive and academic difficulties.
ContributorsAllen, Kelly Anne (Author) / Azuma, Tamiko (Thesis director) / Gallagher, Karen (Committee member) / Department of Speech and Hearing Science (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
DescriptionMy main goal for my thesis is in conjunction with the research I started in the summer of 2010 regarding the creation of a TBI continuous-time sensor. Such goals include: characterizing the proteins in sensing targets while immobilized, while free in solution, and while in free solution in the blood.
ContributorsHaselwood, Brittney (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Cook, Curtiss (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2011-12
Description
The purpose of this project was to examine the viability of protein biomarkers in pre-symptomatic detection of lung cancer. Regular screening has been shown to vastly improve patient survival outcome. Lung cancer currently has the highest occurrence and mortality of all cancers and so a means of screening would be highly beneficial. In this research, the biomarker neuron-specific enolase (Enolase-2, eno2), a marker of small-cell lung cancer, was detected at varying concentrations using electrochemical impedance spectroscopy in order to develop a mathematical model of predicting protein expression based on a measured impedance value at a determined optimum frequency. The extent of protein expression would indicate the possibility of the patient having small-cell lung cancer. The optimum frequency was found to be 459 Hz, and the mathematical model to determine eno2 concentration based on impedance was found to be y = 40.246x + 719.5 with an R2 value of 0.82237. These results suggest that this approach could provide an option for the development of small-cell lung cancer screening utilizing electrochemical technology.
ContributorsEvans, William Ian (Author) / LaBelle, Jeffrey (Thesis director) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
As the United States' military presences in Afghanistan and Iraq are being minimized, an increasing number of veterans are transitioning from the military to pursue higher education opportunities. Due to the military's organizational characteristics, socialization procedures, and performance requirements, this population of students likely faces unique barriers to success in traditional models of higher education. The increase of this unique population necessitates research to evaluate their educationally related social and relational needs so that institutions of higher education will be better able to assist in achieving their academic goals. The student-teacher relationship is a key predictor in students' academic success (Yoon, J. S., 2002). Using survey research, this project examines veteran students' perceptions of their relationships with instructors, characteristics of the organization, communication apprehension with professors and peers, and perceived self-esteem. With the assistance of the Pat Tillman Veterans Center at Arizona State University, approximately 3800 veteran students, in both undergraduate and graduate programs, were invited to participate in the research. The study identified significant relationships between a veteran-student's length of time since separating from military service, their feelings of success as a student, self-esteem, and apprehension of communication with professors. There was also a significant relationships on length of military service, self-esteem, and apprehension of communication with professors.
ContributorsMcconnaughy, Ryan Michael (Author) / Adame, Bradley (Thesis director) / Franks, Tara (Committee member) / Bernard, Daniel (Committee member) / Barrett, The Honors College (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / School of Social and Behavioral Sciences (Contributor) / Hugh Downs School of Human Communication (Contributor)
Created2015-05
Description
In this paper, β-estradiol was characterized utilizing electrochemical impedance spectroscopy (EIS) techniques for the purpose of developing a multi-marker fertility sensor. β-estradiol was immobilized onto the surface of gold disk electrodes to find the optimal binding frequency of estradiol and its respective antibody, anti-17β-estradiol, which was determined to be 37.46Hz. At this frequency a logarithmic relationship between concentration and impedance (Z/ohm) was established creating a concentration calibration curve with a slope of 211 ohm/ln(pg mL-1), an R-squared value of 0.986 and a lower limit of detection of 742 fg mL-1. The specificity and cross-reactivity of the antibody with other hormones was tested through interferent and non-target experiments. Signal-to-noise ratio analysis verified that anti-17β-estradiol exhibited minimal chemical reactions with other hormones (SNR< 3) in non-target experiments. Additionally, there were minimal changes in the amount of signal collected during interferent testing, with albumin and follicle stimulating hormone having SNR values greater than 3. These results, along with the unique frequency response of the antibody-target binding reaction, allow for the possibility of using anti-17β-estradiol and β-estradiol for detecting multiple fertility biomarkers on a single sensor.
ContributorsSmith, Victoria Ann (Author) / LaBelle, Jeffrey (Thesis director) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Diabetes mellitus is a disease characterized by many chronic and acute conditions. With the prevalence and cost quickly increasing, we seek to improve on the current standard of care and create a rapid, label free sensor for glycated albumin (GA) index using electrochemical impedance spectroscopy (EIS). The antibody, anti-HA, was fixed to gold electrodes and a sine wave of sweeping frequencies was induced with a range of HA, GA, and GA with HA concentrations. Each frequency in the impedance sweep was analyzed for highest response and R-squared value. The frequency with both factors optimized is specific for both the antibody-antigen binding interactions with HA and GA and was determined to be 1476 Hz and 1.18 Hz respectively in purified solutions. The correlation slope between the impedance response and concentration for albumin (0 \u2014 5400 mg/dL of albumin) was determined to be 72.28 ohm/ln(mg/dL) with an R-square value of 0.89 with a 2.27 lower limit of detection. The correlation slope between the impedance response and concentration for glycated albumin (0 \u2014 108 mg/dL) was determined to be -876.96 ohm/ln(mg/dL) with an R-squared value of 0.70 with a 0.92 mg/dL lower limit of detection (LLD). The above data confirms that EIS offers a new method of GA detection by providing unique correlation with albumin as well as glycated albumin. The unique frequency response of GA and HA allows for modulation of alternating current signals so that several other markers important in the management of diabetes could be measured with a single sensor. Future work will be necessary to establish multimarker sensing on one electrode.
ContributorsEusebio, Francis Ang (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Acetaminophen, commonly found in Tylenol and other over the counter (OTC) pharmaceuticals, was electrochemically characterized on custom made, flexible, screen printed electrodes (SPEs) to serve as a model target pharmaceutical found in flowing water lines. Carbon, silver/silver chloride, and insulator paste inks were printed onto polyethylene naphthalateolyester (PEN) using custom made stencils for a 4x1 array of 3-electrode electrochemical cells. Cyclic voltammetry was performed to find the electrical potential corresponding to the greatest current response and the experiments were conducted using amperometric current-time mode (AMP*i-t). The physical limitations of SPEs as well as the detection limitations of the target, such as pH and temperature were tested. A concentration gradient of the target was fitted with a linear curve (R2 0.99), and a lower limit of detection of 14.5 μM. It was also found that both pH and temperature affect the current produced by acetaminophen at a fixed concentration, and that the sensors can detect target in a continuous flow. A flow apparatus consisting of an inlet and effluent pipe served as the flow model into which a rolled up flexible electrode array was inserted. The broader goal of this research is to develop a highly sensitive electrode array on flexible substrates which can detect multiple targets simultaneously. Acetaminophen was chosen due to its electro-active properties and its presence in most public water lines in the United States.
ContributorsMaxwell, Stephanie Ann (Author) / LaBelle, Jeffrey (Thesis director) / Allee, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Concussions and traumatic brain injuries are mechanical events which can derive from no specific activity or event. However, these injuries occur often during athletic and sporting events but many athletes experiencing these symptoms go undiagnosed and continue playing without proper medical attention. The current gold standard for diagnosing athletes with concussions is to have medical professionals on the sidelines of events to perform qualitative standardized assessments which may not be performed frequently enough and are not specialized for each athlete. The purpose of this report is to discuss a study sanctioned by Arizona State University's Project HoneyBee and additional affiliations to validate a third-party mouth guard device product to recognize and detect force impacts blown to an athlete's head during athletic activity. Current technology in health monitoring medical devices can allow users to apply this device as an additional safety mechanism for early concussion awareness and diagnosis. This report includes the materials and methods used for experimentation, the discussion of its results, and the complications which occurred and areas for improvement during the preliminary efforts of this project. Participants in the study were five non-varsity ASU Wrestling athletes who volunteered to wear a third-party mouth guard device during sparring contact at practice. Following a needed calibration period for the devices, results were recorded both through visual observation and with the mouth guard devices using an accelerometer and gyroscope. This study provided a sound understanding for the operation and functionality of the mouth guard devices. The mouth guard devices have the capability to provide fundamental avenues of research for future investigations.
ContributorsTielke, Austin Wyatt (Author) / Ross, Heather (Thesis director) / LaBelle, Jeffrey (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Electrochemical sensors function by detecting electroactive species at the electrode surface of a screen printed sensor. As more force is applied, the concentration of electroactive species at the surface of the sensor increases and a larger current is measured. Thus, when all conditions including voltage are made constant, as in Amp i-t, a quantifiable current can be read and the force applied can be calculated. Two common electrochemical techniques in which current is measured, cyclic voltammetry(CV) and amperometric i-t(Amp i-t), were used. A compressible sensor capable of transducing a force and acquiring feedback was created.
ContributorsFeldman, Austin Marc (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Santello, Marco (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
Development of a rapid and label-free Electrochemical Impedance Spectroscopy (EIS) biosensor for Cardiovascular Disease (CVD) detection based on Inerluekin-18 (IL-18) sensitivity was proposed to fill the technology gap between rapid and portable CVD point-of-care diagnosis. IL-18 was chosen for this CVD biosensor due to its ability to detect plaque vulnerability of the heart. Custom (hand) made sensors, which utilized a three electrode configuration with a gold disk working electrode, were created to run EIS using both IL-18 and anti-IL-18 molecules in both purified and blood solutions. The EIS results for IL-18 indicated the optimal detection frequency to be 371Hz. Blood interaction on the working electrode increased the dynamic range of impedance values for the biosensor. Future work includes Developing and testing prototypes of the biosensor along with determining if a Nafion based coating on the working electrode will reduce the dynamic range of impedance values caused by blood interference.
ContributorsJha, Amit (Author) / LaBelle, Jeffrey (Thesis director) / Mossman, Kenneth (Committee member) / Frakes, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / Department of Management (Contributor)
Created2013-05