Biomedical Engineering and Bioengineering Commons^™

Characterization Of The Intrinsic Neural Timescale Indices As A Reliable Fingerprint Of Brain Dynamics, Helya Honarpisheh

Dissertations and Theses

Intrinsic neural timescales (INTs) characterize the persistence of neural activity over time and offer insight into the brain’s temporal hierarchy. This thesis evaluates and compares six autocorrelation-based INT metrics—AR(1) Coefficient (Autoregressive Coefficient at 1), First Zero Lag, Lag at ACF = 1/e, Sum of Positive ACFs, ACF at Half Lag, Exponential Decay Constant (τ)— using resting-state fMRI data from 400 cortical regions across a large, lifespan sample (ages 6– 85) from the NKI-Rockland dataset. A discriminability analysis revealed that the AR(1) coefficient provided the highest test-retest reliability and individual specificity across repeated scans, establishing it as the most reliable INT …

Generation And Characterization Of Human Blood-Brain Barrier Models For Investigating Neuropsychiatric Disorders And Tumor Metastasis, Yunfei Li

Dissertations and Theses

The blood–brain barrier (BBB) is important in the normal function of the central nervous system (CNS). An altered BBB has been described in various neuropsychiatric disorders. The brain-specific microvascular endothelial cell (BMEC) is an essential structural component of the BBB. To test if integrity of the BBB formed by BMECs is compromised in 22q11.2 deletion syndrome (also called DiGeorge syndrome), which is one of the validated genetic risk factors for schizophrenia, a 2D iBBB (induced BBB) on a Transwell filter was generated from human microvascular endothelial cells (HBMECs) derived from the induced pluripotent stem cells (iPSCs) out of patients with …

In Vitro Comparative Study Of Composite Coatings For Magnesium-Based Bone Implants, Abdelrahman Amin, Bryce Williams, Thomas Mcgehee, Alyssandra Navarro, Vipul Patil, Mostafa Elsaadany, Hanna Ibrahim

Biomedical Engineering Faculty Publications and Presentations

This study provides a comparative assessment of the corrosion, morphology, and biological properties of four of the most promising coating methods for magnesium in biomedical applications, namely micro-arc oxidation (MAO), graphene oxide (GO)-containing MAO coating, MAO/sol-gel composite coating, and MAO/polycaprolactone (PCL) polymer dip coating approaches. Despite the abundance of research focused on these promising coating approaches, there is a notable lack of comparative studies evaluating their properties. To this end, the investigated composite coatings are ZK60+MAO, ZK60+MAO/GO, ZK60+MAO/Sol-gel, and ZK60+MAO/PCL composite coating. Several tests were used to assess various properties of the prepared groups such as in vitro corrosion characteristics, …

Interfacing Neural Models: Biocompatibility And Fabrication Of A Flexible, Self-Folding Microelectrode Array, Fernando A. Pesantez Torres

Electronic Theses & Dissertations (2024 - present)

Neurodegenerative diseases pose a formidable challenge in modern medicine, necessitating the development of advanced research tools that can elucidate their complex pathophysiology. Recent advancements in neurodegenerative disease research have led to the development of three-dimensional (3D) neurodegenerative organoids using human induced pluripotent stem cells (hiPSCs). These organoids closely mimic human brain architecture and functionality, providing a valuable tool for understanding complex diseases. Additionally, the ability to generate and study brain organoids consistently and in large quantities holds potential for a controlled in vitro setting and high-throughput drug screening. However, these models are complex systems requiring specialized maintenance, analysis, and manipulation …

Modeling Synergistic Effects Of Integrin And Tgf-Β Signaling In Epithelial Mesenchymal Transition, Prerak Thakkar

Theses and Dissertations

The induction of Epithelial Mesenchymal Transition (EMT) is initiated by a

number of protiens and growth factors, one of which is the profibrotic cytokine Trans-

forming Growth Factor β (TGF-β). Within the extracellular matrix (ECM), TGF-β

is found in a latent, inactive form bound to proteins such as fibronectin (FN). For

TGF-β to contribute to EMT induction, it has to be extracted from the latent com-

plexes into a soluble form. This soluble, activated TGF-β can then bind to receptors

on the cell membrane, which causes the transduction of signals that begin EMT. Re-

search has shown that the release …

Strength Imbalances And Shoulder Pain In Manual Wheelchair Users Stratified By Age Of Spinal Cord Injury/Disorder (Sci/D) Onset, Ashlyn M. Jones

Theses and Dissertations

Introduction The majority of manual wheelchair users (MWUs) with spinal cord injury or disorder (SCI/D) develop shoulder pain. In adults with SCI/D, there is evidence that upper limb strength imbalances are associated with shoulder pain. However, strength imbalances may indicate protective compensatory strategies, and other factors may be important contributors to pain. Currently, personalized prevention and management of pain is limited, little is known about joint strength imbalances and pain in children who use manual wheelchairs, and the effect of the age of SCI/D onset is poorly understood. The purpose of this study was to assess the effect of age …

Molecular Characterization Of Leptin Gene In Sheep (Ovis Aries), Shahenda M. Hegazy, Mohamed Fouda, Ahmed Ateya, Huda A. El Emam

Mansoura Veterinary Medical Journal

INTRODUCTION: Advances in molecular genetic techniques have simplified the process of identifying individual differences at the DNA level. Genetic polymorphisms at candidate genes controlling economic features have recently drawn a lot of scholarly attention due to their potential as a tool for genetic selection and the identification of evolutionary linkages in livestock. OBJECTIVE: This work aimed to detect nucleotide sequence variants in Lep gene as genetic markers for growth and heat tolerance traits in Barki and Abudeleik sheep using PCR-DNA sequencing approach in search of single nucleotide polymorphisms (SNPs). METHODS: 30 female ewes, 15 of each breed (Barki and Aboudeleik) …

Intercellular Mitochondrial Transfer Contributes To Microenvironmental Redirection Of Cancer Cell Fate, Julie Sofie Bjerring, Yara Khodour, Emilee Anne Peterson, Patrick Christian Sachs, Robert David Bruno

School of Medical Diagnostics & Translational Sciences Publications

The mammary microenvironment has been shown to suppress tumor progression by redirecting cancer cells to adopt a normal mammary epithelial progenitor fate in vivo. However, the mechanism(s) by which this alteration occurs has yet to be defined. Here, we test the hypothesis that mitochondrial transfer from normal mammary epithelial cells to breast cancer cells plays a role in this redirection process. We evaluate mitochondrial transfer in 2D and 3D organoids using our unique 3D bioprinting system to produce chimeric organoids containing normal and cancer cells. We demonstrate that breast cancer tumoroid growth is hindered following interaction with mammary epithelial cells …

Systematic Co-Culture Of Ipsc-Cm And Ipsc-An Promote Co-Maturation In Vitro, William Gregory Terrell Jr.

Graduate Dissertations and Theses

The cardiac microenvironment is a complex system of multicellular interactions that enables proper heart function. In native heart muscle, sympathetic neurons (SN) and parasympathetic neurons (PSN) modulate the beat rate of cardiomyocytes (CM) to maintain homeostasis. Pluripotent stem cells can differentiate into CM, but differentiated CMs are fetal-like, with a high beat rate, and lack organized sarcomeric structure. Recent reports of co-cultured pluripotent CM/SN pairs have reported electrophysiological changes in the SN (increased upstroke velocity). However, interpretation of these results are obscured by the differences in co-culture parameters between studies (stage of development, co-culture duration, etc.). The goal of this …

Your Foot Is Not A Brick: Using A Multi-Segment Foot Model To Explore The Actions Of The Ankle-Foot Complex During Uneven Terrain Gait., Tayler Jon Hoekstra

Dissertations and Theses

The field of biomechanics has seen continued development of models to be used and circumstances to be considered. An increasing number of more complex models for the foot known as multi-segment foot models (MSFMs) have created opportunities to better understand the compensatory motion of this vital portion of human anatomy. This research seeks to utilize one such MSFM model to increase understanding in how human ambulation changes in uneven terrain environments. Unique inner-foot joints defined by the Rizzoli foot model (RFM) were measured for and compared for subjects traversing both even and uneven terrain to quantify joints that experienced significant …

The Implementation And Miniaturization Of A New Current Source Into The Consolidated Layout Of An Electrical Impedance Tomography Probe With A Novel Approach To Electrode Layout, Katherine M. Bullion

Dartmouth College Master’s Theses

Prostate cancer is the most highly diagnosed form of cancer in male subjects in the United States. As a result, over 100,000 radical prostatectomies are performed annually in the US [1]. However, it is currently very difficult for surgeons to confirm that all impacted tissues have been effectively removed from the patient. Positive surgical margins are an independent risk factor for the recurrence of cancer, yet currently there is no method to efficiently, intraoperatively assess the status of surgical margins during a radical prostatectomy. There is a need for a new tool that is small enough to fit into a …

Laser-Induced Graphene For Early Disease Detection: A Review, Sri Ramulu Torati, Gymama Slaughter

Center for Bioelectronics Publications

Electrochemical biosensors have been instrumental in early disease detection, facilitating effective monitoring and treatment. The emergence of graphene has significantly advanced sensor technology in various fields, including biomedicine, electronics, and energy. In this landscape, laser‐induced graphene (LIG) has emerged as a superior alternative to conventional graphene synthesis methods. Its straightforward fabrication process and compatibility with wearable devices boost its practicality and potential for real‐world applications. This review highlights the transformative potential of LIG in biosensing, showcasing its contributions to the development of next‐generation diagnostic tools for early disease detection. An overview of the LIG synthesis process and its applications in …

Cost-Effective Hierarchical Cobalt Nanostructured Laser-Induced Graphene For Enhanced Uric Acid Detection, Anju Joshi, Gymama Slaughter

Center for Bioelectronics Publications

This study presents an innovative, cost-effective strategy to develop a flexible, enzyme-free biosensor for the sensitive detection of uric acid (UA). Utilizing electrochemically modified cobalt nanostructured on laser-induced graphene electrodes (CoNCs/LIG), this approach surpasses traditional noble metal-based electrocatalysts in sensitivity and affordability. The one-step electrochemical modification method is efficient and straightforward, enabling the uniform deposition of hierarchical flower-like cobalt nanostructures. These structures synergistically enhance the performance of the LIG, resulting in a broad detection range of 5 to 700 µM with a sensitivity of 6.75 µA µM^-¹ cm^-² and a low detection limit of 3.66 µM for UA. …

Molecular Imprinting And Nanomaterial Synergy For Lactate Detection, Christopher Animashaun, Gymama Slaughter

Center for Bioelectronics Publications

Molecularly imprinted polymer (MIP)-based electrochemical sensors have emerged as promising non-enzymatic platforms for the selective and stable detection of clinically and environmentally relevant biomarkers. This review provides a critical, comprehensive analysis of recent advances in MIP-based lactate sensing, with particular emphasis on hybrid systems that integrate conductive nanomaterials including gold and silver nanoparticles, laser-induced graphene, and reduced graphene oxide. These synergistic combinations leverage enhanced surface area, electrical conductivity, and molecular recognition to improve sensor sensitivity, selectivity, and long-term operational stability. Key fabrication strategies, such as electropolymerization, green nanomaterial synthesis, and surface imprinting, are critically examined for their roles in optimizing …

Advances In Bacterial Cellulose-Based Scaffolds For Tissue Engineering: Review, Rewati Raman Ujjwal, Gymama Slaughter

Center for Bioelectronics Publications

Bacterial cellulose (BC) has emerged as a highly versatile and promising biomaterial in tissue engineering, with potential applications across skin, bone, cartilage, and vascular regeneration. Its exceptional properties like high mechanical strength, superior biocompatibility, excellent moisture retention, and inherent ability to support cell adhesion and proliferation, make BC particularly effective for wound healing and skin regeneration. These attributes accelerate tissue repair and foster new tissue formation, highlighting its value in skin-related applications. Additionally, BC's capacity to support osteogenic differentiation, combined with its mechanical robustness, positions it as a strong candidate for bone tissue engineering, facilitating regeneration and repair. Recent advancements …

Electrochemical And Nanomaterial Based Strategies For Nonenzymatic Glucose Detection: A Review, Reagan Aviha, Gymama Slaughter

Center for Bioelectronics Publications

Electrochemical glucose sensing technologies have undergone significant evolution, with continual advancements aimed at improving sensitivity, selectivity, and user convenience. This review systematically explores the development of emerging nonenzymatic glucose sensor designs. Nonenzymatic sensors are critically evaluated for their ability to overcome enzymatic limitations, leveraging novel materials and catalytic mechanisms. Additionally, the emergence of smartphone-integrated glucose monitoring systems is highlighted as the fifth generation, representing a paradigm shift toward personalized, real-time healthcare management. Emphasis is placed on the strategies employed to reduce the working electrode potential and enhance analytical performance. Key analytical metrics and real-sample applicability are evaluated, and persistent challenges …

Gold Nanoparticle-Enhanced Molecularly Imprinted Polymer Electrode For Non-Enzymatic Lactate Sensing, Christopher Animashaun, Abdellatif Ait Lahcen, Gymama Slaughter

Center for Bioelectronics Publications

We are reporting the development of a high-performance, non-enzymatic electrochemical biosensor for selective lactate detection, integrating laser-induced graphene (LIG), gold nanoparticles (AuNPs), and a molecularly imprinted polymer (MIP) synthesized from poly(3,4-ethylenedioxythiophene) (PEDOT). The LIG electrode offers a highly porous, conductive scaffold, while electrodeposited AuNPs enhance catalytic activity and signal amplification. The PEDOT-based MIP layer, electropolymerized via cyclic voltammetry, imparts molecular specificity by creating lactate-specific binding sites. Cyclic voltammetry confirmed successful molecular imprinting and enhanced interfacial electron transfer. The resulting LIG/AuNPs/MIP biosensor demonstrated a wide linear detection range from 0.1 µM to 2500 µM, with a sensitivity of 22.42 µA/log(µM) and …

Automation To Autonomy: Temporal Dynamics Of Trust And Visual Attention Allocation Did Not Evolve, Tetsuya Sato, Eric Chancey, Yusuke Yamani

Psychology Faculty Publications

Emerging work environments are expected to implement autonomy that performs various functions without human input. Previous works has shown that trust in automation is negatively correlated with visual attention allocation, indicating that trust is a dynamic construct. Moreover, trust in automation and trust in autonomy appears to evolve in similar ways. However, recent work has demonstrated differences between trust in automation and trust in autonomy within Kaber’s (2018) theoretical framework (Sato et al., 2023b). Yet, it is uncertain whether the development of trust and visual attention allocation differs between automation and autonomy. The present study examined the temporal dynamics of …

3d Bioprinting Technology Innovation In Female Reproductive System, Siyao Chen, Tongxin Wang, Jiaqi Chen, Mingxing Sui, Luyao Wang, Xueyu Zhao, Jianqiao Sun, Yingli Lu

Department of Obstetrics & Gynecology Faculty Publications

Several diseases affect the female reproductive system, and both disease factors and treatments impact its integrity and function. Consequently, understanding the mechanisms of disease occurrence and exploring treatment methods are key research focuses in obstetrics and gynecology. However, constructing accurate disease models requires a microenvironment closely resembling the human body, and current animal models and 2D in vitro cell models fall short in this regard. Thus, innovative in vitro female reproductive system models are urgently needed. Additionally, female reproductive system diseases often cause tissue loss, yet effective tissue repair and regeneration have long been a bottleneck in the medical field. …

Viscoelastic Property Analysis Of A Magnetorheological Elastomer Micropump For Insulin Delivery In Type 1 Diabetes, Victor Buitimea

College of Graduate Studies: Theses & Dissertations

Over two decades, there has been a significant rise in awareness regarding Type 1 Diabetes (T1D), leading to a deeper comprehension of numerous variables, including hereditary factors, patterns of occurrence, and health challenges. According to the Type 1 Diabetic Index, around 8.7 million people worldwide are affected by this chronic autoimmune illness marked by a lack of insulin and hyperglycemia. The introduction of artificial pancreas systems could save more than half a million patients by 2040. Despite the availability of various insulin delivery technologies that are offered to diabetic patients, many still are skeptical of this modern system. The issues …

Synthesis And Assessment Of Biobased Acrylated Epoxidized Soybean Oil Resins For Stereolithography 3d Printing Of Microfluidic Devices, Natalie S. Romero Figueroa

College of Graduate Studies: Theses & Dissertations

This research focuses on the development and characterization of a biobased photocurable resin synthesized from soybean oil for use in stereolithography (SLA) 3D printing of microfluidic devices. The study explores a sustainable alternative to petroleum-based resins by performing an acrylation reaction on epoxidized soybean oil (ESO) to produce acrylated epoxidized soybean oil (AESO), which was then formulated into a photocurable resin with the addition of a photo initiator. The fabrication process involved designing microfluidic molds in SolidWorks and printing them using an Elegoo Mars 4 SLA printer under various exposure and layer thickness parameters. The printed samples consisted of microchannels …

Enhancing The Mechanical Properties Of Sla 3d-Printed Bio-Resin From Linseed Oil Using Cellulose And Lignin Biopolymers, Chukwunonso A. Ikedionu

College of Graduate Studies: Theses & Dissertations

Abstract

This research explores the development of bio resin from linseed oil by the process of epoxidation and acrylation to produce acrylated epoxidized linseed oil (AELO). Lignin and cellulose biopolymers were added as reinforcement at varying weight fractions of 1 wt.%, 2.5 wt.%, and 5 wt.%, and their mechanical performance was compared against pure AELO. The formulations were printed using an Elegoo SLA 3D printer to create standardized test specimens like tensile bars, compression cylinders, and hardness blocks, which were all prepared according to the ASTM testing standard.

The results indicate that reinforcement effects depend on both filler type and …

Optimization Of Small-Scale Bioreactors For Increased Pdna Production And Yield, Laura M. Hills

Honors Theses and Capstones

No abstract provided.

Synthesis Of Bio-Orthogonal Hydrogels For 3d Cell Culture Via Penicillamine Β-Thiolactone-Mediated Native Chemical Ligation, Kaelin E. Marshall, Matthew E. Currier, Nathan J. Oldenhuis

Honors Theses and Capstones

Many hydrogel systems designed to mimic the extracellular matrix (ECM) employ thiol-based chemistries with undesirable functional groups, including vinyl sulfones and methacrylates. In downstream applications, any unreacted functional groups are problematic and render hydrogels non-viable for human use. Here, we introduce modifications to the Native Chemical Ligation (NCL) mechanism, exploring the elimination of cytotoxic byproducts and increased reaction rate by using a β-thiolactone. The inclusion of the β-thiolactone results in retention of the thiol within the gel, as well as enhanced kinetics due to the thermodynamic favorability of the ring opening and amide formation. We achieved this by functionalizing 4-arm …

Coldstartcpi: Induced-Fit Theory-Guided Dti Predictive Model With Improved Generalization Performance, Qichang Zhao, Haochen Zhao, Linyuan Gao, Kai Zheng, Yajie Li, Qiao Ling, Jing Tang, Yaohang Li, Jianxin Wang

Computer Science Faculty Publications

Predicting compound-protein interactions (CPIs) plays a crucial role in drug discovery. Traditional methods, based on the key-lock theory and rigid docking, often fail with novel compounds and proteins due to their inability to account for molecular flexibility and the high sparsity of CPI data. Here, we introduce ColdstartCPI, a framework inspired by induced-fit theory, which leverages unsupervised pre-training features and a Transformer module to learn both compound and protein characteristics. ColdstartCPI treats proteins and compounds as flexible molecules during inference, aligning with biological insights. It outperforms state-of-the-art sequence-based models, particularly for unseen compounds and proteins, and shows strong generalization capability …

Insights In Adaptation: Examining Self-Reflection Strategies Of Job Seekers With Visual Impairments In India, Akshay Kolgar Nayak, Yash Prakash, Sampath Jayarathna, Hae-Na Lee, Vikas Ashok

Computer Science Faculty Publications

Significant changes in the digital employment landscape, driven by rapid technological advancements and the COVID-19 pandemic, have introduced new opportunities for blind and visually impaired (BVI) individuals in developing countries like India. However, a significant portion of the BVI population in India remains unemployed despite extensive accessibility advancements and job search interventions. Therefore, we conducted semi-structured interviews with 20 BVI persons who were either pursuing or recently sought employment in the digital industry. Our findings reveal that despite gaining digital literacy and extensive training, BVI individuals struggle to meet industry requirements for fulfilling job openings. While they engage in self-reflection …

Optical Methods For Time-Resolved Dosimetry And Oximetry Of Ultra-High Dose Rate Radiation Therapy, Megan A. Clark

Dartmouth College Ph.D Dissertations

Radiotherapy (RT) is a cornerstone method used to treat over 50% of the 2 million new cancer diagnoses each year in the United States. The success of RT directly relies on an optimal balance between maximizing the dose to the tumor while minimizing dose to surrounding normal tissues. Achieving this balance is often challenging due to underlying radiation transport and the presence of anatomical constraints that limit the beam delivery geometry. In turn, minimizing healthy tissue toxicity prevents use of a more aggressive tumor killing approach, and even in curative cases may decrease the patient’s quality of life due to …

Benchmarking Batch-Effect Correction Methods Towards The Construction Of A Triple-Negative Breast Cancer Cell Atlas, Peter Scheible, Amy H. Tang, Jing He, Jiangwen Sun

Computer Science Faculty Publications

Triple-negative breast cancer (TNBC) requires detailed cellular mapping given its aggressive nature, immense tumor heterogeneity and genetic diversity. We integrated 156,794 cells from six scRNA-seq datasets—including tumors, metastases, and cell lines—to build a TNBC scRNA cell atlas, focusing on batch effect mitigation while maintaining biological and molecular details. Preprocessing f ilters noise, normalizes data, and leverages PCA for integration readiness. We utilized scANVI, a semi-supervised tool, to align datasets, preserving TNBC’s complex tumor heterogeneity via marker annotations [1]. UMAPs demonstrate biological clustering in integrated data, contrasted with datasetdriven unintegrated patterns. Assessments verifying effective batch correction. This method aligns with NASA’s …

Non-Invasive Glucose Monitoring Using Ppg, Ai, And Iot-Driven Mobile Integration For Real-Time Diabetes Management, Mostafa Abdelaziz, Amr Refaie

Mechanical Engineering

Diabetes mellitus patients must regularly monitor their blood glucose levels to manage glycaemia, typically requiring capillary tests at least three times daily and laboratory tests one to two times per month. These conventional methods involve finger pricking, causing significant discomfort and stress. This study introduces an innovative non-invasive glucose monitoring approach by integrating photoplethysmography (PPG) technology with an artificial intelligence (AI) algorithm, complemented by a mobile application using Flutter, IoT systems, and Firebase cloud for real-time data access. Among the AI models tested, polynomial regression demonstrated superior accuracy in glucose prediction, achieving a Mean Squared Error (MSE) of 14.76 and …

Comparative Analysis Of Electrode Encapsulation Reliability: Planar Vs. Thermoformed Interdigitated Neural Electrodes In Biomedical Engineering, Tatum Peyerl

Graduate Theses, Dissertations, and Problem Reports (ETD)

Durable dielectric encapsulation is crucial for the long-term function of implantable neural electrodes; however, the reliability of curved, thermoformed coatings remains underexplored. This study addresses that gap by comparing planar (non-thermoformed) and thermoformed interdigitated neural electrodes (IDEs) encapsulated in Polyimide-2611. Both device types underwent accelerated in vitro aging in phosphate‑buffered saline (PBS) at 67 °C for approximately 91 days, simulating two years of physiological exposure. Post-accelerated aging evaluation included electrochemical impedance spectroscopy (EIS) from 0.1 Hz to 100 kHz to monitor moisture‑induced leakage, and high‑voltage breakdown testing under saline immersion to assess dielectric strength. After aging, all electrodes maintained impedance …