Biomedical Engineering and Bioengineering Commons^™

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

Use Of Surface-Enhanced Raman Scattering (Sers) Probes To Detect Fatty Acid Receptor Activity In A Microfluidic Device, Han Zhang, Wei Zhang, Lifu Xiao, Yan Liu, Timothy A. Gilbertson, Anhong Zhou

Biological Engineering Faculty Publications

In this study, 4-mercaptobenzoic acid (MBA)-Au nanorods conjugated with a GPR120 antibody were developed as a highly sensitive surface-enhanced Raman spectroscopy (SERS) probe, and were applied to detect the interaction of fatty acids (FA) and their cognate receptor, GPR120, on the surface of human embryonic kidney cells (HEK293-GPRR120) cultured in a polydimethylsiloxane (PDMS) microfluidic device. Importantly, the two dominant characteristic SERS peaks of the Raman reporter molecule MBA, 1078 cm⁻¹ and 1581 cm⁻¹, do not overlap with the main Raman peaks from the PDMS substrate when the appropriate spectral scanning range is selected, which effectively avoided the …

Improved Production Of Antifungal Angucycline Sch47554 By Manipulating Three Regulatory Genes In Streptomyces Sp. Scc-2136, Ozkan Fidan, Riming Yan, Du Zhu, Jixun Zhan

Biological Engineering Faculty Publications

Sch47554 and Sch47555 are two angucyclines with antifungal activities against various yeasts and dermatophytes from Streptomyces sp. SCC‐2136. The schgene cluster contains several putative regulatory genes. Both schA4 and schA21were predicted as the TetR family transcriptional regulators, whereas schA16shared significant similarity to the AraC family transcriptional regulators. Although Sch47554 is the major product of Streptomyces sp. SCC‐2136, its titer is only 6.72 mg/L. This work aimed to increase the production of this promising antifungal compound by investigating and manipulating the regulatory genes in the Sch47554 biosynthetic pathway. Disruption of schA4and schA16 led to a significant increase …

Fluoride Removal From Water Using A 3d Printed Calcium Carbonate Filter, Sophia Bakar, David Kahler, Benjamin S. Goldschmidt

Undergraduate Research and Scholarship Symposium

Groundwater containing high concentrations of fluoride is the most common source of drinking water in rural areas in parts of east Africa, India, and China. The elevated levels of fluoride cause skeletal and dental fluorosis, which is the weakening and decay of bone structures due to the leeching of calcium from the body as calcium and fluoride bond by the process of adsorption. Over 150 million people are suffering from some form of fluorosis due to the consumption of groundwater. Calcium carbonate has been demonstrated to influence fluoride removal in several forms. To make fluoride removal a cost-effective and user-friendly …

Quantifying Iron Overload Using Mri, Active Contours, And Convolutional Neural Networks, Andrea Sajewski, Stacey Levine

Undergraduate Research and Scholarship Symposium

Iron overload, a complication of repeated blood transfusions, can cause tissue damage and organ failure. The body has no regulatory mechanism to excrete excess iron, so iron overload must be closely monitored to guide therapy and measure treatment response. The concentration of iron in the liver is a reliable marker for total body iron content and is now measured noninvasively with magnetic resonance imaging (MRI). MRI produces a diagnostic image by measuring the signals emitted from the body in the presence of a constant magnetic field and radiofrequency pulses. At each pixel, the signal decay constant, T2*, can be calculated, …

Novel Calibrated Short Tr Recovery (Castrr) Method For Brain-Blood Partition Coefficient Correction Enhances Gray-White Matter Contrast In Blood Flow Measurements In Mice, Scott W. Thalman, David K. Powell, Ai-Ling Lin

Biomedical Engineering Faculty Publications

The goal of the study was to develop a novel, rapid Calibrated Short TR Recovery (CaSTRR) method to measure the brain-blood partition coefficient (BBPC) in mice. The BBPC is necessary for quantifying cerebral blood flow (CBF) using tracer-based techniques like arterial spin labeling (ASL), but previous techniques required prohibitively long acquisition times so a constant BBPC equal to 0.9 mL/g is typically used regardless of studied species, condition, or disease. An accelerated method of BBPC correction could improve regional specificity in CBF maps particularly in white matter. Male C57Bl/6N mice (n = 8) were scanned at 7T using CaSTRR …

Kinematics During Knee Extension, Lunge, And Chair Rise, Center For Orthopaedic Biomechanics, Kevin Shelburne, Phd, Michael D. Harris, Phd, Vasiliki Kefala, Donald R. Hume, Bradley S. Davidson, A. J. Cyr, R. H. Kim, A. A. Ali, E. M. Mannen

Living Kinematics of the Knee

No abstract provided.

Automated Atrial Fibrillation Detection From Electrocardiogram, Senbao Lu

Bioengineering Master's Theses

In this study, a novel Atrial Fibrillation (AFib) detection algorithm is presented based on Electrocardiography (ECG) signals. In particular, the spectrogram of ECG signal is used as an input to a Convolutional Neural Network (CNN) to classify normal and AFib ECG signals. This model is shown to perform well with an accuracy of 92.91% and a value of 0.9789 for the area under the ROC curve (AUC). This study demonstrated the potential of using image classification methods and CNN model to detect abnormal biosignals with noise.

Assessment Of Hand Gestures Using Wearable Sensors And Fuzzy Logic, Angel Cardenas, Ryan Messersmith, Will Newcomb

Bioengineering Senior Theses

Hand dexterity and motor control are critical in our everyday lives because a significant portion of the daily motions we perform are with our hands and require some degree of repetition and skill. Therefore, development of technologies for hand and extremity rehabilitation is a significant area of research that will directly help patients recovering from hand debilities sustained from causes ranging from stroke and Parkinson’s disease to trauma and common injuries. Cyclic activity recognition and assessment is appropriate for hand and extremity rehabilitation because a majority of our essential motions are cyclic in their nature. For a patient on the …

Nebuflask: Advancing Usability Of Nebulizers To Increase Patient Compliance, Murray Bartho, Michael Breshock, Megan Nolte

Bioengineering Senior Theses

Nebulizers are ubiquitous in the world of medicine. Any patient diagnosed with asthma, pneumonia, cystic fibrosis, chronic obstructive pulmonary disorder (COPD), or any other severe lung disease often use a nebulizer in order to deliver medication to the lungs. Although these technologies are quite common, they are surprisingly outdated. The most commonly used nebulizers today are bulky, loud, awkward to carry around, and must be plugged into an outlet. These aspects of the nebulizer make it a nuisance to use in general and almost impossible to use outside of the home or clinic. The ultrasonic and mesh nebulizers do address …

High-Throughput, Portable Microfluidic Aptamer Assay, Atticus Mccoy, Matthew Curtin

Bioengineering Senior Theses

Aptamer-based assays are a powerful platform for sensing a wide variety of biochemical targets, including drugs, disease biomarker, and biomolecules. However, aptamer assays often lack rapid identification and high-throughput screening. Performing an aptamer-based assay on a microfluidic device is a promising solution to increase throughput, portability, and sensitivity. In this paper, we present a microfluidic device capable of running aptamer-based assays. Our device utilizes normally-closed valves and a central micropump to move fluids throughout the chip. One chip could theoretically be scaled up to run multiple assays, and multiple of these microfluidic devices could be run in parallel to increase …

Noninvasive Screening Of A Fecal Biomarker For Human Necrotizing Enterocolitis (Nec), Daniela Campa, Kyle Sullivan

Bioengineering Senior Theses

Necrotizing enterocolitis (NEC) is a disease that predominantly affects preterm infants. Of the 10% of preterm neonates that develop NEC, about one in four cases results in death. The pathophysiology presents as inflammation of intestinal epithelial cell lining and subsequent tissue death, sometimes resulting in intestinal perforations. The underlying mechanisms have yet to be comprehensively identified. Diagnosis--the rate limiting step in reducing critical disease-onset-to-treatment time--is based on relatively nonspecific signs, impeding early and accurate diagnosis. This project, a collaborative effort between Santa Clara and Stanford Universities, aims to improve current diagnostic methods by identifying the first verifiable and useful fecal …

Regularized Fourier Ptychographic Microscopy, Shiqi Xu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Quantitative phase image (QPI) is a popular microscopy technique for studying cell morphology. Recently, Fourier ptychographic microscopy (FPM) has emerged as a low-cost computational microscopy technique for forming high-resolution wide-field QPI images by taking multiple images from different illumination angles. However, the applicability of FPM to dynamic imaging is limited by its high data requirement. In this thesis, we propose new methods for highly compressive FPM imaging using a data-adaptive sparse coding and an online plug-and-play (PnP) method with non-local priors based on the fast iterative shrinkage/threshold algorithm (FISTA). We validate the proposed method on both simulated and experimental data …

An Anatomical Basis Of The Differential Cholinergic Modulation Of Valence-Specific Pyramidal Neurons In The Basolateral Amygdala, Nguyen Vu

Theses and Dissertations

Emotion is a crucial component of the decision-making process. The amygdala, known as the “orchestrator” of the emotion circuit, associates emotional valence with incoming sensory stimuli and thus contributes to decision- making. Within the basolateral nucleus of the amygdala (BLA), spatially segregated and genetically distinct pyramidal neurons (PNs) have been identified based on their correspondence to distinct behavioral stimuli. These PNs project to several brain regions mediating different aspects of the emotional spectrum.

For example, BLA PNs projecting to prelimbic (PL) and infralimbic (IL) cortex are involved in fear acquisition and fear extinction, respectively. However, the mechanism by which these …

Soft Palate Modification Using A Collagen Crosslinking Reagent For Equine Dorsal Displacement Of The Soft Palate And Other Upper Airway Breathing Disorders, Stephanie Hunt, Jonathan Kuo, Fabio A Aristizabal, Matt Brown, Abhijit R. Patwardhan, Thomas Hedman

Biomedical Engineering Faculty Publications

The mechanical properties of the soft palate can be associated with breathing abnormalities. Dorsal displacement of the soft palate (DDSP) is a naturally occurring equine soft palate disorder caused by displacement of the caudal edge of the soft palate. Snoring and a more serious, sometimes life-threatening, condition called obstructive sleep apnea (OSA) are forms of sleep-related breathing disorders in humans which may involve the soft palate. The goal of this study was to investigate the effect of injecting the protein crosslinker genipin into the soft palate to modify its mechanical properties for the treatment of equine DDSP with potential implications …

Primitive Palms: A Density Study On The Impacts Of Harvesting Natural Materials For Construction Purposes On Sumak Allpa Of The Amazon Rainforest, Zachary Bull

Independent Study Project (ISP) Collection

In an effort to better understand how rural construction techniques affect a surrounding environment, this study combines a density test of the natural building materials used in the construction of a school on Sumak Allpa island of the Orellana Province in the Amazon basin of Ecuador. The focus of the study measures the density of the bamboo species Guadua angustifolia and the Panama hat plant Carludovica palmata on the island while noting a comprehensive compilation of the techniques and materials used in the building process. Using a mix of plots and transects, a comparison of harvested material to remaining material …

Implementation Of A Particle Image Velocimetry System For Evaluation Of Microfluidic Chip Flows, Sheila Mallenahalli

Honors Capstones

No abstract provided.

Material Analysis Of A Tympanostomy Myringotomy Simulator, Abishek Stanley

Honors Capstones

No abstract provided.

Human-Centered Electric Prosthetic (Help) Hand, Jamie Ferris, Shiyin Lim, Michael Mehta, Evan Misuraca

Interdisciplinary Design Senior Theses

Through a partnership with Indian non-profit Bhagwan Mahaveer Viklang Sahayata Samiti, we designed a functional, robust, and and low cost electrically powered prosthetic hand that communicates with unilateral, transradial, urban Indian amputees through a biointerface. The device uses compliant tendon actuation, a small linear servo, and a wearable garment outfitted with flex sensors to produce a device that, once placed inside a prosthetic glove, is anthropomorphic in both look and feel. The prosthesis was developed such that future groups can design for manufacturing and distribution in India.

Generation Of Silver Nanoparticle Pharmacokinetic Profiles In A Lung Model, Rachel Galaska

Honors Theses

Nanomaterial technologies are becoming increasingly prevalent in consumer and industrial applications, including drug delivery, energy harvesting, environmental applications, and medicine due to their unique physiochemical properties. As nanomaterial use increases, so too does human exposure. This has made it progressively more important to understand the toxicological effects of nanomaterials and their interactions with the human body. Silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials due to their antibacterial properties. As inhalation is one of the most common exposure routes, understanding the toxicity of these AgNPs on lung tissue was studied. Using A549 cells for a lung tissue …