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Description
Filtration for microfluidic sample-collection devices is desirable for sample selection, concentration, preprocessing, and downstream manipulation, but microfabricating the required sub-micrometer filtration structure is an elaborate process. This thesis presents a simple method to fabricate polydimethylsiloxane (PDMS) devices with an integrated membrane filter that will sample, lyse, and extract the DNA from microorganisms in aqueous environments. An off-the-shelf membrane filter disc was embedded in a PDMS layer and sequentially bound with other PDMS channel layers. No leakage was observed during filtration. This device was validated by concentrating a large amount of cyanobacterium Synechocystis in simulated sample water with consistent performance across devices. After accumulating sufficient biomass on the filter, a sequential electrochemical lysing process was performed by applying 5VDC across the filter. This device was further evaluated by delivering several samples of differing concentrations of cyanobacterium Synechocystis then quantifying the DNA using real-time PCR. Lastly, an environmental sample was run through the device and the amount of photosynthetic microorganisms present in the water was determined. The major breakthroughs in this design are low energy demand, cheap materials, simple design, straightforward fabrication, and robust performance, together enabling wide-utility of similar chip-based devices for field-deployable operations in environmental micro-biotechnology.
ContributorsLecluse, Aurelie (Author) / Meldrum, Deirdre (Thesis advisor) / Chao, Joseph (Thesis advisor) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2011
Description
Single cell phenotypic heterogeneity studies reveal more information about the pathogenesis process than conventional bulk methods. Furthermore, investigation of the individual cellular response mechanism during rapid environmental changes can only be achieved at single cell level. By enabling the study of cellular morphology, a single cell three-dimensional (3D) imaging system can be used to diagnose fatal diseases, such as cancer, at an early stage. One proven method, CellCT, accomplishes 3D imaging by rotating a single cell around a fixed axis. However, some existing cell rotating mechanisms require either intricate microfabrication, and some fail to provide a suitable environment for living cells. This thesis develops a microvorterx chamber that allows living cells to be rotated by hydrodynamic alone while facilitating imaging access. In this thesis work, 1) the new chamber design was developed through numerical simulation. Simulations revealed that in order to form a microvortex in the side chamber, the ratio of the chamber opening to the channel width must be smaller than one. After comparing different chamber designs, the trapezoidal side chamber was selected because it demonstrated controllable circulation and met the imaging requirements. Microvortex properties were not sensitive to the chambers with interface angles ranging from 0.32 to 0.64. A similar trend was observed when chamber heights were larger than chamber opening. 2) Micro-particle image velocimetry was used to characterize microvortices and validate simulation results. Agreement between experimentation and simulation confirmed that numerical simulation was an effective method for chamber design. 3) Finally, cell rotation experiments were performed in the trapezoidal side chamber. The experimental results demonstrated cell rotational rates ranging from 12 to 29 rpm for regular cells. With a volumetric flow rate of 0.5 µL/s, an irregular cell rotated at a mean rate of 97 ± 3 rpm. Rotational rates can be changed by altering inlet flow rates.
ContributorsZhang, Wenjie (Author) / Frakes, David (Thesis advisor) / Meldrum, Deirdre (Thesis advisor) / Chao, Shih-hui (Committee member) / Wang, Xiao (Committee member) / Arizona State University (Publisher)
Created2011
Description
Laboratory automation systems have seen a lot of technological advances in recent times. As a result, the software that is written for them are becoming increasingly sophisticated. Existing software architectures and standards are targeted to a wider domain of software development and need to be customized in order to use them for developing software for laboratory automation systems. This thesis proposes an architecture that is based on existing software architectural paradigms and is specifically tailored to developing software for a laboratory automation system. The architecture is based on fairly autonomous software components that can be distributed across multiple computers. The components in the architecture make use of asynchronous communication methodologies that are facilitated by passing messages between one another. The architecture can be used to develop software that is distributed, responsive and thread-safe. The thesis also proposes a framework that has been developed to implement the ideas proposed by the architecture. The framework is used to develop software that is scalable, distributed, responsive and thread-safe. The framework currently has components to control very commonly used laboratory automation devices such as mechanical stages, cameras, and also to do common laboratory automation functionalities such as imaging.
ContributorsKuppuswamy, Venkataramanan (Author) / Meldrum, Deirdre (Thesis advisor) / Collofello, James (Thesis advisor) / Sarjoughian, Hessam S. (Committee member) / Johnson, Roger (Committee member) / Arizona State University (Publisher)
Created2012
Description
Single cell analysis has become increasingly important in understanding disease onset, progression, treatment and prognosis, especially when applied to cancer where cellular responses are highly heterogeneous. Through the advent of single cell computerized tomography (Cell-CT), researchers and clinicians now have the ability to obtain high resolution three-dimensional (3D) reconstructions of single cells. Yet to date, no live-cell compatible version of the technology exists. In this thesis, a microfluidic chip with the ability to rotate live single cells in hydrodynamic microvortices about an axis parallel to the optical focal plane has been demonstrated. The chip utilizes a novel 3D microchamber design arranged beneath a main channel creating flow detachment into the chamber, producing recirculating flow conditions. Single cells are flowed through the main channel, held in the center of the microvortex by an optical trap, and rotated by the forces induced by the recirculating fluid flow. Computational fluid dynamics (CFD) was employed to optimize the geometry of the microchamber. Two methods for the fabrication of the 3D microchamber were devised: anisotropic etching of silicon and backside diffuser photolithography (BDPL). First, the optimization of the silicon etching conditions was demonstrated through design of experiment (DOE). In addition, a non-conventional method of soft-lithography was demonstrated which incorporates the use of two positive molds, one of the main channel and the other of the microchambers, compressed together during replication to produce a single ultra-thin (<200 µm) negative used for device assembly. Second, methods for using thick negative photoresists such as SU-8 with BDPL have been developed which include a new simple and effective method for promoting the adhesion of SU-8 to glass. An assembly method that bonds two individual ultra-thin (<100 µm) replications of the channel and the microfeatures has also been demonstrated. Finally, a pressure driven pumping system with nanoliter per minute flow rate regulation, sub-second response times, and < 3% flow variability has been designed and characterized. The fabrication and assembly of this device is inexpensive and utilizes simple variants of conventional microfluidic fabrication techniques, making it easily accessible to the single cell analysis community.
ContributorsMyers, Jakrey R (Author) / Meldrum, Deirdre (Thesis advisor) / Johnson, Roger (Committee member) / Frakes, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
I conducted a qualitative, comparative study on the nursing education systems in the United Kingdom and the United States, focusing on two universities—Arizona State University in Phoenix, Arizona and Leeds Beckett University in Leeds, England. The goals of my thesis included comparing the educational, economic, and cultural aspects of the countries and how those aspects impact nursing students on both sides of the pond. The educational and economic aspects were compared by utilizing existing literature and open data sources such as the university websites and publications from comparative education journals, while the cultural differences were evaluated by conducting short, one-on-one interviews with students enrolled in the Adult Health courses at both universities. The findings from the interviews were transcribed and coded, and findings from the sites were compared. While there is an extensive amount of research published regarding comparative education, there has not been much published comparing these developed countries. While there is a significant difference in the structure and cost of the nursing programs, there are more similarities than differences in culture between nursing students interviewed in the US and those interviewed in the UK.
ContributorsTahiliani, Shreja (Author) / Hagler, Debra (Thesis director) / Allen, Angela (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The goal of this creative project is to explain the different roles of advanced practice nursing as well as the role of a registered nurse. Advanced practice nursing roles include Certified Nurse Practitioner, Certified Registered Nurse Anesthetist, Certified Clinical Nurse Specialist, and Certified Nurse Midwife. The role of the registered nurse is included in this website because this role is the foundation for becoming an advanced practice nurse and is an equally important role. The target audience for the website is potential nursing students, current nursing students, and licensed nurses who desire to advance their career and are looking for more information about each role. This comprehensive website includes the scope of practice, salary, educational programs, and an interview with a nurse in each role. The description of each advanced practice role includes audio and visual aids to appeal to different types of learners. In depth education regarding advanced practice nursing roles will make current and future nurses more aware of the endless possibilities of a career in nursing. Nurses provide education to patients every day, but there is rarely adequate education provided to nurses regarding their profession or professional advancement opportunities. Nursing is a patient-focused career and sometimes nurses forget to focus on their own personal growth while caring for others. This one-stop website promotes nurse to nurse education by thoroughly explaining each advanced practice role. All of the information in this website is publically available through the internet and this website is meant solely for educational purposes.
ContributorsThompson, Rachel (Co-author) / Banchik, Jennifer (Co-author) / Peterson, Katherine (Thesis director) / Kriz, Lindsey (Committee member) / Spahr, Nancy (Committee member) / School of Community Resources and Development (Contributor) / School of Social Transformation (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
Colorectal cancer (CRC) is the third most prevalent form of cancer in both genders and second highest cause of cancer-related death in the United States. Despite the availability of preventative CRC screening, Latinos as a group are of particular concern for CRC as they tend to have a lower screening rate, contributing to the possibility of late-stage diagnosis or even death. However, little is known about the perceptions of CRC screening and factors which contribute to beliefs about CRC in Latinos. Most studies are quantitative and rarely include a qualitative approach focusing on cultural aspects and communication with physicians. The purpose of this study was to explore participants' perceived facilitators and barriers to CRC screening, as well as perspectives on physician recommendation and fatalism, using a qualitative approach. A convenience and snowball sampling were used to collect the data. Eight English-speaking Latino individuals (M age=56 years; 75% female) in the Phoenix, Arizona area were invited to 60-90 minute in-depth interviews on perceptions of the colorectal cancer screening process. Ten major themes emerged from the interviews: (1) lacking awareness and knowledge of CRC screening, (2) attitude toward CRC and screening, (3) availability of preventive care, (4) physician trust, (5) fear, (6) desire for increased information, (7) personal learning, (8) lifestyle factors, (9) cultural impact, and (10) willingness to change lifestyle. Results indicated varying levels of perceived knowledge of colorectal cancer, little perceived risk of diagnosis, desire for more information, and a high level of physician trust. Implications for nursing included increased need for CRC screening educational resources, as well as further investigation of the influence of fatalistic belief in CRC screening compliance for the Latino population.
ContributorsMagdaleno, Claire Rose (Author) / Kim, Sunny (Thesis director) / McNulty, Julie (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
This past summer, I met a young lady named Ashley (name has been changed) who has been diagnosed with chronic Lyme disease. Upon researching this condition in greater detail, I learned that many medical providers who base their practice on the best evidence do not support treating patients for a chronic Lyme infection, the existence of which has not been substantially supported with research. I inquired about the process that led her to seek treatment for chronic Lyme disease at Jemsek Specialty Clinic. I learned that after many inaccurate diagnoses and years of unhelpful treatments, Ashley finally rejected the help offered by traditional medical doctors because she felt they were uncaring and inattentive, and went somewhere she felt heard. What she deserved, however, was both care that was based in scientific research and care that felt compassionate, as has been promoted by the nursing field. Despite the lack of a confirmed medical diagnosis, Ashley's day to day symptoms and struggles could be addressed with nursing care. I then constructed a nursing care plan to be implemented by Ashley's family and friends to help her feel her best and live a fulfilling life despite chronic disease. Patients should not have to choose between a healthcare provider who utilizes the strongest scientific evidence and one they feel understands them, though many do. Nursing can unite these mindsets by alleviating the daily challenges patients face. Please see the website http://careplanforashley.blogspot.com
ContributorsKnochel, Amanda Marie (Author) / Panchmatia, Bella (Thesis director) / Mishark, Kenneth (Committee member) / Barrett, The Honors College (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor)
Created2014-05
Description
The purpose of this study was to determine whether a peer nursing student who presents a longitudinal case study on warfarin in a pharmacology course classroom influences prelicensure and postbaccalaureate nursing students' knowledge and perceived knowledge about warfarin. The study was a descriptive design that used a convenience sample of baccalaureate nursing students enrolled in two pharmacology courses. All participating students answered warfarin case-study questions and completed a self-demographic questionnaire, a knowledge pretest and posttest, and a self-efficacy questionnaire after the activity, which evaluated students' knowledge and perceived knowledge on 11 warfarin concepts. For all students (N = 89), the number of correct answers improved significantly between pretests and posttests for Items 2-11 (p < .0001; Wilcoxon signed-rank tests), which evaluated students' knowledge on warfarin's site of action, associated laboratory values, use of vitamin K, and food-drug interactions. However, no significant difference was seen in the number of correct answers for warfarin's mechanism of action. Comparing prelicensure and postbaccalaureate groups by Mann-Whitney tests, no significant difference was seen for pretest total scores (median 7.00, n = 55; median 7.50, n = 34; respectively; p = .399). Similarly, no difference was seen for posttest total scores by groups (prelicensure: median = 9.00, n =54; postbaccalaureate: median = 10.00, n = 32; p = .344). Overall, students in both groups agreed that they could identify and explain all 11 warfarin concepts. The Pearson correlation between the total posttest and total self-efficacy scores for the combined group was .338 (p = .003), demonstrating a low but significant correlation between students' posttest total scores and their perceived warfarin knowledge, as evaluated by the self-efficacy questionnaire.
ContributorsLam, Wing Tung (Author) / Vana, Kimberly (Thesis director) / Holcomb, Cynthia (Committee member) / Silva, Graciela (Committee member) / Barrett, The Honors College (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / W. P. Carey School of Business (Contributor)
Created2014-12
Description
The S.T.O.M.P. (Supporting Teen Outcomes Mentorship Program) program has been developed to provide assistance for the adolescent parenting dynamic. The purpose of S.T.O.M.P. is to serve as an additional aid to support a number of adolescent mothers participating in a group-based support program at Chandler Regional Medical Center, but to initiate core values, skills, and social networks for the young mothers. A collection of current literature in support of one-on-one mentorship programs, comprehensive needs as identified by the adolescent pregnant population, personal experience and findings, as well as collaborative discussions amongst health educators has supported the identification of the core objectives of this creative project; the development of a one-on-one mentorship program.
ContributorsThompson, Sarah Lynn (Author) / Jasper, Marcia (Thesis director) / Murphy, Ana Orrantia (Committee member) / Barrett, The Honors College (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor)
Created2014-05