Engineering Commons^™

Resolving The Three-Dimensional Rotational And Translational Dynamics Of Single Molecules Using Radially And Azimuthally Polarized Fluorescence, Oumeng Zhang, Weiyan Zhou, Jin Lu, Tingting Wu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We report a radially and azimuthally polarized (raPol) microscope for high detection and estimation performance in single-molecule orientation-localization microscopy (SMOLM). With 5000 photons detected from Nile red (NR) transiently bound within supported lipid bilayers (SLBs), raPol SMOLM achieves 2.9 nm localization precision, 1.5° orientation precision, and 0.17 sr precision in estimating rotational wobble. Within DPPC SLBs, SMOLM imaging reveals the existence of randomly oriented binding pockets that prevent NR from freely exploring all orientations. Treating the SLBs with cholesterol-loaded methyl-β-cyclodextrin (MβCD-chol) causes NR’s orientational diffusion to be dramatically reduced, but curiously NR’s median lateral displacements drastically increase from 20.8 to …

Development Of Radiochemical Quality Control Methods For Ra-223 And Th-227 Radiotherapies, Abigail Hasson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Introduction. Radiolabeled molecules for use in disease detection and targeted treatment are a mainstay of patient management. The majority of radiopharmaceuticals deployed to date undergo a single radioactive transition (decay) to reach a stable ground state. Complex emitters, which produce a series of daughter radionuclides, are emerging as novel radiopharmaceuticals, and there is a need for the proper validation of content and purity using common quality control instrumentation. Hypothesis. There is a need for proper characterization of complex emitters for more accurate quality control on readily available equipment. Here, we demonstrate the novel characterization of Th-227 and Ra-223 using a …

Control Flow Integrity For Real-Time Embedded Systems, Yuqian Huo

McKelvey School of Engineering Graduate Student Theses & Dissertations

Devices built on embedded systems are widely used in our daily lives. Nowadays, firmware typically uses C and C++ for efficiency and durability. However, those languages are unsafe which can lead to many software and system security issues. Attackers can easily corrupt a system by issuing various memory corruption attacks on a vulnerable program. Control-flow integrity is one of the most prevalent mechanisms used to protect against memory corruption. Most research papers and prototypes focus on using CFI on high-performance chips such as Intel and ARM Cortex-A. However, many embedded systems targeting time critical services are built on resource constrained …

Identifying Structures For Ion Channel Kinetic Models, Kathryn Mangold

McKelvey School of Engineering Graduate Student Theses & Dissertations

Voltage-gated ion channels carry transmembrane current and underlie the voltages changes seen during the action potential. The ion channels open and close precisely, or gate, in response to voltage to create the specific cellular action potential waveform. The first models of voltage-gated ion channels gating dynamics were described by Hodgkin and Huxley when studying the neuronal action potential in the squid giant axon. While the probabilistic gating variables cleverly imagined by Hodgkin and Huxley to describe channel gating are still used today to describe cardiac ionic currents, Markov (or state-dependent) models provide a more accurate representation of channel dynamics. As …

Laser Stimulated Dynamic Thermal Imaging System For Tumor Detection, Hongyu Meng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Laser stimulated dynamic thermal imaging system for tumor detectionby Hongyu Meng Doctor of Philosophy in Biomedical Engineering Washington University in St. Louis, 2021 Professor Samuel Achilefu, Chair Recent advances in infrared sensor technology have enabled the rapid application of thermal imaging in materials science, security and medicine. Relying on the infrared characteristics of living systems, thermal imaging has been used to generate individual heat maps, detect inflammation and tumor. As an imaging system, thermal imaging has the advantages of portability, real-time, non-invasive, and non-contact. But the low specificity of thermal imaging hinders its wide clinical application.

Unfortunately, label-free DTI is …

Interfacial Engineering And Photoelectrochemistry Of Patterned Metal/Semiconductor Heterostructures, Che Tan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoelectrochemical (PEC) cells enable the conversion of solar energy into storable fuels, which is critical in overcoming the intermittent nature of this largest renewable source. However, the majority of semiconductors used as photoelectrodes in these cells have low conversion efficiencies and/or stabilities. Silicon (Si) is an attractive semiconductor material for photoelectrodes, but the development of efficient Si-based photoanodes is challenging due to their instability in alkaline solutions. Thus, one focus of this dissertation is the design and fabrication of highly stable nickel (Ni)-patterned Si photoanodes through interfacial engineering of the barrier heights. Recently, hot carriers in plasmonic metal nanostructures have …

Advancements In Pressurized Oxy-Combustion Process: Pollutant Control And Process Development, Piyush Kumar Verma

McKelvey School of Engineering Graduate Student Theses & Dissertations

The emission of carbon dioxide from the power industry is one of the major causes of climate change. However, it is well established that the development of human societies across the globe depends on reliable and dispatchable power, which are generally the source of these emissions. There has been a recent growth in the integration of intermittent sources such as wind and solar which are carbon free. But these intermittent sources have significant temporal changes in power production and thus lack reliability and dispatchablity. This is a complicated problem to solve. However, flexible power plants with carbon capture and storage, …

Plasmonically-Enhanced Dna-Rna Hybrid-Based Bioassay For Amplification-Free Quantification Of Sars-Cov-2, Yuxiong Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Corona Virus Disease 2019 (COIVD-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly infectious respiratory illness. Within just a few months, it spread around the whole world and became a global pandemic. Real-time reverse-transcription polymerase chain reaction (RT-PCR) works as a gold standard method diagnosing COVID-19 with high sensitivity and specificity. But due to the programs of RT-PCR, it usually takes more than 24 hours to get the results while specialized devices are also required. False-negative results can happen as well using RT-PCR which increase the risk of spreading coronavirus. To promote quicker detection of COVID-19, …

Numerical Investigations Of Logic Gates And Transistors In Quantum And Classical Information Processing, Anthony Corbin

McKelvey School of Engineering Graduate Student Theses & Dissertations

The development of numerical analysis techniques for electromagnetics and quantum mechanics problems has dramatically increased the rate of new discoveries. Propelled by the exponential growth of computers over the past decades, numerical software has brought the ability to reliably experiment with new ideas and predict new phenomena, even before the physical realizations of these ideas in the labs. This work will demonstrate the application of this capability by applying numerical analysis techniques to design and analyze new devices. First, a system of optical logic gates using a nonlinear metallodielectric grating is completely designed and simulated using numerical analysis. Second, the …

Quantifying Components Of Protein Translation And Metabolite Heterogeneity In Isogenic Microbial Populations, Alexander Schmitz

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cell-to-cell variation in gene expression and metabolite levels have a significant impact on ensemble productivity of microbial bioproduction. New metabolic engineering tools and approaches are needed that consider cell cultures as an amalgam of uniquely behaving individuals to improve the slow commercialization of metabolically engineered systems. Stochastic cellular process including gene expression, metabolism, and growth lead to phenotypic variation between genetically identical cells. Understanding and the ability to control microbial phenotypic variation is key to improving microbial bioproduction metrics. During protein translation, codon usage strongly influences ensemble gene expression but the effect on the variation of gene expression was not …

Zebrafish Models Of Katp Channelopathies, Soma S. Singareddy

McKelvey School of Engineering Graduate Student Theses & Dissertations

Much work has been carried out to understand the composition, structure, and function of ATP-sensitive potassium (KATP) channels in mammalian tissues, as well as the molecular basis of the channelopathies that result from loss-of-function or gain-of-function mutations in these channels. These studies have also highlighted that the available pharmacology to treat such diseases is limited. To overcome such limitations, a better understanding of the tissue specificity of expression, the exact mechanisms linking the molecular dysfunction to the development of complex pathophysiology, the potential for reducing cross-reactivity of drugs, and ultimately more specific therapies are needed. The work described in this …

Short-Term Memory And Olfactory Signal Processing, Lijun Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Modern neural recording methodologies, including multi-electrode and optical recordings, allow us to monitor the large population of neurons with high temporal resolution. Such recordings provide rich datasets that are expected to understand better how information about the external world is internally represented and how these representations are altered over time. Achieving this goal requires the development of novel pattern recognition methods and/or the application of existing statistical methods in novel ways to gain insights into basic neural computational principles. In this dissertation, I will take this data-driven approach to dissect the role of short-term memory in olfactory signal processing in …

Addressing Pragmatic Challenges In Utilizing Ai For Security Of Industrial Iot, Maede Zolanvari

McKelvey School of Engineering Graduate Student Theses & Dissertations

Industrial control systems (ICSs) are an essential part of every nation's critical infrastructure and have been utilized for a long time to supervise industrial machines and processes. Today’s ICSs are substantially different from the information technology (IT) devices a decade ago. The integration of internet of things (IoT) technology has made them more efficient and optimized, improved automation, and increased quality and compliance. Now, they are a sub (and arguably the most critical) part of IoT's domain, called industrial IoT (IIoT).

In the past, to secure ICSs from malicious outside attack, these systems were isolated from the outside world. However, …

Development And Application Of A Novel Acoustic Microfluidic Technology For Single Cell Per Well Trapping And High-Resolution Analysis Of Cilia Motion In Chlamydomonas Reinhardtii, Mingyang Cui

McKelvey School of Engineering Graduate Student Theses & Dissertations

Acoustic manipulation of cells and microorganisms is a label-free and contact-free technique with promise for biological and biomedical applications. When exposed to an ultrasonic standing wave field, particles suspended in microfluidic channels will be moved to pressure minima (nodes) or maxima (antinodes) due to the acoustic impedance mismatch between particles and the suspension medium. Cilia motion is fundamental to understanding biological and biomedical problems related to dysfunctional human cilia, including primary ciliary dyskinesia, blindness, and male infertility. However, in vivo and ex vivo mammalian ciliated cell research is laborious and time-consuming due to difficulty in growing, maintaining, and imaging these …

Photoacoustic Imaging Of Colorectal Cancer And Ovarian Cancer, Xiandong Leng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoacoustic (PA) imaging is an emerging hybrid imaging technology that uses a short-pulsed laser to excite tissue. The resulting photoacoustic waves are used to image the optical absorption distribution of the tissue, which is directly related to micro-vessel networks and thus to tumor angiogenesis, a key process in tumor growth and metastasis. In this thesis, the acoustic-resolution photoacoustic microscopy (AR-PAM) was first investigated on its role in human colorectal tissue imaging, and the optical-resolution photoacoustic microscopy (OR-PAM) was investigated on its role in human ovarian tissue imaging.Colorectal cancer is the second leading cause of cancer death in the United States. …

Acoustic Radiation Force And Its Application For Cell Manipulation And Ion Channels Activation, Xiangjun Peng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Sound is a stress wave that carries energy and momentum flux. Scattered sound waves can generate acoustic radiation force that can be used to manipulate particles or cells. This dissertation demonstrates the physics behind cell manipulation by ultrasound. The work begins with a detailed analysis of the mechanics of using standing surface acoustic waves to fabricate acoustic tweezers for contactless particle manipulation using acoustic radiation force. Models to design and analyze acoustic radiation force have traditionally relied on plane wave theories that cannot predict how standing surface acoustic waves can levitate cells in the direction perpendicular to the substrate. We …

Anion Exchange Membranes In Electrochemical Energy Systems, Yunzhu Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Non-CO2-emitting sources of renewable energy, such as solar and wind, have become quite popular in recent years, and their electricity generation cost at scale has become comparable with that of gas- and coal-fired power plants. However, their intermittent output makes the resultant electricity hard to dispatch in a reliable manner in the absence of grid-scale electrical energy storage (EES) technologies. Redox-flow batteries (RFBs) are promising devices for medium- to large-scale electric energy storage. They are safe, reliable, and portable, and are designed with decoupled power and energy modules, which makes it easy and cost-effective to scale their output to meet …

Defining The Role Of Elastic Fibers In Tendon Mechanics, Jeremy D. Eekhoff

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tendons serve as a linking component of the musculoskeletal system by transferring forces between muscle and bone. As such, the structural proteins of the tendon extracellular matrix are of vital importance for the tissue to function properly and maintain its mechanical integrity. Collagen is the principal constituent of tendon and makes up its aligned hierarchical organization. Other structural proteins, such as elastin, are in comparison understudied and not well understood in relation to tendon function. Elastin, the main component of elastic fibers, has unique mechanical properties including high extensibility, fatigue resistance, and elasticity; these properties are important for elastin-rich tissues …

Predicting Patient Outcomes With Machine Learning For Diverse Health Data, Dingwen Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

As digitized clinical and health data become ubiquitous, machine learning techniques have shown promise in predicting various clinical outcomes. In this thesis research, we exploit three types of data including (1) data collected through wearables outside hospitals, (2) electronic health records (EHR) data of inpatient in general hospital wards, (3) intraoperative data collected during surgery. This thesis work investigates machine learning approaches for the diverse clinical and health data with distinctive characteristics and challenges in the context of real-world clinical applications. Specifically, this thesis makes the following contributions to the state of the art of clinical machine learning.

Extracting informative …

A Case Study On Hls Portability From Intel To Xilinx Fpgas, Zhili Xiao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Field-programmable gate arrays (FPGAs) are a hardware accelerator option that is growing in popularity. However, FPGAs are notoriously hard to program. To this end, high-level synthesis (HLS) tools have been developed to allow programmers to design hardware accelerators with FPGAs using familiar software languages. The two largest FPGA vendors, Intel and Xilinx, support both C/C++ and OpenCL C to construct kernels. However, little is known about the portability of designs between these two platforms. In this work, we evaluate the portability and performance of Intel and Xilinx kernels. We conduct a case study, porting the Needleman-Wunsch application from the Rodinia …

Deep Learning For Automatic Microscopy Image Analysis, Shenghua He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Microscopy imaging techniques allow for the creation of detailed images of cells (or nuclei) and have been widely employed for cell studies in biological research and disease diagnosis in clinic practices.Microscopy image analysis (MIA), with tasks of cell detection, cell classification, and cell counting, etc., can assist with the quantitative analysis of cells and provide useful information for a cellular-level understanding of biological activities and pathology. Manual MIA is tedious, time-consuming, prone to subject errors, and are not feasible for the high-throughput cell analysis process. Thus, automatic MIA methods can facilitate all kinds of biological studies and clinical tasks. Conventional …

Improving Resource Efficiency In Cloud Computing, Jiayi Song

McKelvey School of Engineering Graduate Student Theses & Dissertations

Customers inside the cloud computing market are heterogeneous in several aspects, e.g., willingness to pay and performance requirement. By taking advantage of trade-offs created by these heterogeneities, the service provider can realize a more efficient system. This thesis is concerned with methods to improve the utilization of cloud infrastructure resources, and with the role of pricing in realizing those improvements and leveraging heterogeneity. Towards improving utilization, we explore methods to optimize network usage through traffic engineering. Particularly, we introduce a novel optimization framework to decrease the bandwidth required by inter-data center networks through traffic scheduling and shaping, and then propose …

Effects Of Tendon Viscoelasticity On The Distribution Of Forces Across Sutures In A Model Tendon-To-Bone Repair, Yuxuan Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tears to the rotator cuff often require surgical repair. These repairs often culminate in re-tearing when sutures break through the tendon in the weeks following repair. Numerous studies have been performed to identify suturing strategies that reduce this risk by balancing forces across sutures. However, the structural engineering basis for these approaches is still emerging, and the effects of tendon mechanics on load balancing is still unclear. Specifically, the effects of the viscoelastic nature of tendon on load sharing have not been established. With the aim of providing insight into this problem, this thesis studies how tendon viscoelasticity, tendon stiffness, …

Nevr: Learning Continuous Neural Video Representation With Local Feature Codes For Video Interpolation, Wentao Shangguan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Video frame interpolation aims to synthesis a non-exists intermediate frame guided by two successive frames. Recently, some work shows excellent results in learning continuous representation of temporally-varying 3D objects with neural field (NF), which could be used for interpolating the original video. However, these methods require several videos from different viewing angles, the information of camera poses, learning for each specific scene, and achieving sub-optimal results for video frame interpolation. To this end, we propose a new learning neural field representation-based model, Neural Video Representation (NeVR) to learn a continuous representation of videos for high-quality video interpolation. Unlike the traditional …

Toward Lignin Valorization: Development Of Rhodococcus Opacus Pd630 As A Chassis For Triacylglycerol (Tag) Production From Recalcitrant Aromatic Feedstocks, Rhiannon R. Carr

McKelvey School of Engineering Graduate Student Theses & Dissertations

The advent of the industrial era was precipitated by the discovery of fossil fuels, and ushered in unprecedented changes for humanity included but not limited to the development of rapid transit and communications, improvements to food distribution and preservation, the mass production of goods, and a radical rearrangement of communities from relatively small enclaves to metropolises. With all the benefits, however, come considerable costs, especially to the global environment. Greenhouse gas emissions, built up over centuries of unregulated combustion, have precipitated a rate of global temperature change unparalleled in the 4.5 billion-year history of this planet. In order to preserve …

Single-Molecule Localization Microscopy Of 3d Orientation And Anisotropic Wobble Using A Polarized Vortex Point Spread Function, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Within condensed matter, single fluorophores are sensitive probes of their chemical environments, but it is difficult to use their limited photon budget to image precisely their positions, 3D orientations, and rotational diffusion simultaneously. We demonstrate the polarized vortex point spread function (PSF) for measuring these parameters, including characterizing the anisotropy of a molecule’s wobble, simultaneously from a single image. Even when imaging dim emitters (∼500 photons detected), the polarized vortex PSF can obtain 12 nm localization precision, 4°–8° orientation precision, and 26° wobble precision. We use the vortex PSF to measure the emission anisotropy of fluorescent beads, the wobble dynamics …

Mems 411: Safely Capturing Giant African Pouch Rats, Anthony Brown, John Christensen, Jared Harrison

Mechanical Engineering Design Project Class

We were tasked with designing a trap to safely capture Giant African Pouch Rats. The traps are used in both urban and rural environments that include city streets, basements, farms, river beds, and bushes among other locations. Pouch rats are much larger than most rats and are a very ferocious species; they will harm themselves if there are any non-smooth surfaces when captured. It is very important that we designed a trap with this safety top of mind.

Mems 411: Rowing Force Plate, Mae Hubel, Taylor Southwick, Miles Petersen

Mechanical Engineering Design Project Class

The Rowing Force Plate is a device that is designed to measure a rower’s force
over time so that they can understand how hard they are rowing. Most rowing
aids communicate the speed at which someone is rowing, which is variant on water
speed, wind speed, and other inconsistent environmental and situational factors.
Force, however, can be consistently measured and is a better indicator of effort a
rower is exerting. Other products that measure force do exist, but use complex and
expensive technology, unlike our design.
After brainstorming and analyzing multiple possible designs, we concluded to use
four force sensors …

Mems 411: Lost Grains Thresher, Alicia Gupte, Sophie Fox, Dan Heikes, Andrew Waldherr

Mechanical Engineering Design Project Class

The Lost Grains Thresher project aims to design and implement a device that can successfully separate the seed and chaff from various grains that are native to the greater St. Louis area. This project is designed for Dr. Natalie Mueller at Washington University in St. Louis to replace her current method of separating plant seeds from chaff by hand. This project focused on three main performance goals: 1) the device should work on a minimum of two types of seeds and thresh them to an acceptable quality, 2) the device should be easily cleaned and reset within three minutes, and …

Mems 411: Q.T. B-Bar, Gambian Pouched Rat Trap, Benjamin W. Horine Jr., Ileane Ho, Sarangi Pathirana

Mechanical Engineering Design Project Class

To design and build an improved rat trap that will effectively capture a Gambian Pouched Rat of larger size ensuring the rodents' safety, easy deployment in natural environments, simple mechanical release mechanisms, and cost-effectiveness.