Matching Items (4)
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Description
Micro-electro-mechanical systems (MEMS) film bulk acoustic resonator (FBAR) demonstrates label-free biosensing capabilities and is considered to be a promising alternative of quartz crystal microbalance (QCM). FBARs achieve great success in vacuum, or in the air, but find limited applications in liquid media because squeeze damping significantly degrades quality factor (Q)

Micro-electro-mechanical systems (MEMS) film bulk acoustic resonator (FBAR) demonstrates label-free biosensing capabilities and is considered to be a promising alternative of quartz crystal microbalance (QCM). FBARs achieve great success in vacuum, or in the air, but find limited applications in liquid media because squeeze damping significantly degrades quality factor (Q) and results in poor frequency resolution. A transmission-line model shows that by confining the liquid in a thickness comparable to the acoustic wavelength of the resonator, Q can be considerably improved. The devices exhibit damped oscillatory patterns of Q as the liquid thickness varies. Q assumes its maxima and minima when the channel thickness is an odd and even multiple of the quarter-wavelength of the resonance, respectively. Microfluidic channels are integrated with longitudinal-mode FBARs (L-FBARs) to realize this design; a tenfold improvement of Q over fully-immersed devices is experimentally verified. Microfluidic integrated FBAR sensors have been demonstrated for detecting protein binding in liquid and monitoring the Vroman effect (the competitive protein adsorption behavior), showing their potential as a promising bio-analytical tool. A contour-mode FBAR (C-FBAR) is developed to further improve Q and to alleviate the need for complex integration of microfluidic channels. The C-FBAR consists of a suspended piezoelectric ring made of aluminum nitride and is excited in the fundamental radial-extensional mode. By replacing the squeeze damping with shear damping, high Qs (189 in water and 77 in human whole blood) are obtained in semi-infinite depth liquids. The C-FBAR sensors are characterized by aptamer - thrombin binding pairs and aqueous glycerine solutions for mass and viscosity sensing schemes, respectively. The C-FBAR sensor demonstrates accurate viscosity measurement from 1 to 10 centipoise, and can be deployed to monitor in-vitro blood coagulation processes in real time. Results show that its resonant frequency decreases as the viscosity of the blood increases during the fibrin generation process after the coagulation cascade. The coagulation time and the start/end of the fibrin generation are quantitatively determined, showing the C-FBAR can be a low-cost, portable yet reliable tool for hemostasis diagnostics.
ContributorsXu, Wencheng (Author) / Chae, Junseok (Thesis advisor) / Phillips, Stephen (Committee member) / Cao, Yu (Committee member) / Kozicki, Michael (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Microfluidics has shown great potential in rapid isolation, sorting, and concentration of bioparticles upon its discovery. Over the past decades, significant improvements have been made in device fabrication techniques and microfluidic methodologies. As a result, considerable microfluidic-based isolation and concentration techniques have been developed, particularly for rapid pathogen detection. Among

Microfluidics has shown great potential in rapid isolation, sorting, and concentration of bioparticles upon its discovery. Over the past decades, significant improvements have been made in device fabrication techniques and microfluidic methodologies. As a result, considerable microfluidic-based isolation and concentration techniques have been developed, particularly for rapid pathogen detection. Among all microfluidic techniques, dielectrophoresis (DEP) is one of the most effective and efficient techniques to quickly isolate and separate polarizable particles under inhomogeneous electric field. To date, extensive studies have demonstrated that DEP devices are able to precisely manipulate cells ranging from over 10 μm (mammalian cells) down to about 1 μm (small bacteria). However, very limited DEP studies on manipulating submicron bioparticles, such as viruses, have been reported.

In this dissertation, rapid capture and concentration of two different and representative types of virus particles (Sindbis virus and bacteriophage M13) with gradient insulator-based DEP (g-iDEP) has been demonstrated. Sindbis virus has a near-spherical shape with a diameter ~68 nm, while bacteriophage M13 has a filamentous shape with a length ~900 nm and a diameter ~6 nm. Under specific g-iDEP experimental conditions, the concentration of Sindbis virus can be increased two to six times within only a few seconds, using easily accessible voltages as low as 70 V. A similar phenomenon is also observed with bacteriophage M13. Meanwhile, their different DEP behavior predicts the potential of separating viruses with carefully designed microchannels and choices of experimental condition.

DEP-based microfluidics also shows great potential in manipulating blood samples, specifically rapid separations of blood cells and proteins. To investigate the ability of g-iDEP device in blood sample manipulation, some proofs of principle work was accomplished including separating two cardiac disease-related proteins (myoglobin and heart-type fatty acid binding protein) and red blood cells (RBCs). Consistent separation was observed, showing retention of RBCs and passage of the two spiked protein biomarkers. The numerical concentration of RBCs was reduced (~70 percent after one minute) with the purified proteins available for detection or further processing. This study explores and extends the use of the device from differentiating similar particles to acting as a sample pretreatment step.
ContributorsDing, Jie (Author) / Hayes, Mark A. (Thesis advisor) / Ros, Alexandra (Committee member) / Buttry, Daniel A (Committee member) / Arizona State University (Publisher)
Created2017
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Description
Blood donations today undergo extensive screening for transfusion transmitted infections (TTI) since the discovery of the first infectious agent in the early 1900s. Nucleic Acid Testing (NAT) is a serological test used widely in disease detection. NAT is known to rapidly and effectively detect pathogenic genomic material in blood by

Blood donations today undergo extensive screening for transfusion transmitted infections (TTI) since the discovery of the first infectious agent in the early 1900s. Nucleic Acid Testing (NAT) is a serological test used widely in disease detection. NAT is known to rapidly and effectively detect pathogenic genomic material in blood by reducing the "window period" of infection. However, NAT produces false negative results for disease positive samples posing a risk of disease transmission. Therefore, NAT is used in conjunction with the Enzyme-Linked Immunosorbent Assay (ELISA) to mitigate these risks. However, the ELISA assay also poses the same risk as NAT. This study proposes immunosignaturing as an alternative serological test that may combat this risk and investigates whether it would be more effective than other standardized serological tests in disease detection. Immunosignaturing detects antibodies by utilizing a microarray of randomized peptide sequences. Immunosignaturing provides information about an individual's immune health from the pattern of reactivity of antibody-peptide binding. Unlike ELISA and NAT, immunosignaturing can be programmed to detect any disease and detect multiple diseases simultaneously. Using ELISA, NAT, and immunosignaturing, immune profiles of asymptomatic patients were constructed for 10 different classes of blood borne diseases. A pattern of infection was identified for each disease and the sensitivity and specificity of these assays were assessed relative to each other. Results indicate that immunosignaturing can be a viable diagnostic tool in blood testing. Immunosignatures demonstrated increased sensitivity and specificity compared to ELISA and NAT in discerning disease positive and negative samples within and across different classes of disease.
ContributorsSharma, Megumi (Author) / McFadden, Grant (Thesis director) / Nickerson, Cheryl (Committee member) / Green, Alex (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description

This thesis focuses on Bram Stoker’s 1897 British novel 'Dracula' and its association of medical technology with a myriad of Victorian British societal anxieties, facilitating an examination of current and historical fears about medical intervention and medical innovation. Dracula’s parallel yet opposite portrayals of blood transfusion and vampirism allow fears

This thesis focuses on Bram Stoker’s 1897 British novel 'Dracula' and its association of medical technology with a myriad of Victorian British societal anxieties, facilitating an examination of current and historical fears about medical intervention and medical innovation. Dracula’s parallel yet opposite portrayals of blood transfusion and vampirism allow fears of medical technology to be exaggerated and explored within the realm of the supernatural. In Dracula and today, the desire to restore the health of ourselves and our loved ones is accompanied by fears that medical treatment will cause harm; will reshape our conceptualization of death and thus our relationship with death; and, as new technologies with unestablished consequences are employed, that medical intervention may in fact erode our basic identity and humanity.

ContributorsBoyden, Autumn (Author) / Agruss, David (Thesis director) / MacCord, Katherine (Committee member) / Soares, Rebecca (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05