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Full-Text Articles in Engineering

การพัฒนาเท้าเทียมแบบปรับความแข็งสปริงสำหรับผู้พิการขาขาดระดับกิจกรรมต่ำ, ธิติธรรม์ ธรรมวินทร Jan 2019

การพัฒนาเท้าเทียมแบบปรับความแข็งสปริงสำหรับผู้พิการขาขาดระดับกิจกรรมต่ำ, ธิติธรรม์ ธรรมวินทร

Chulalongkorn University Theses and Dissertations (Chula ETD)

ผู้พิการขาขาดมีความแข็งสปริงข้อเท้าเทียมที่เหมาะสมกับตนเองแตกต่างกันไปด้วยสาเหตุจากน้ำหนัก รองเท้า ลักษณะการใช้ชีวิต และความชอบส่วนบุคคุล ในกลุ่มนี้มีผู้พิการขาขาดระดับกิจกรรมต่ำ K-level 1และ2 ซึ่งมีแนวโน้มเพิ่มขึ้นตามสัดส่วนผู้สูงอายุที่จะเพิ่มขึ้นในอนาคต ปัญหาเหล่านี้นำมาสู่การสร้างงานวิจัยภายใต้วัตถุประสงค์ว่าออกแบบและผลิตเท้าเทียมแบบปรับความแข็งสปริง(Stiffness)สำหรับผู้พิการระดับกิจกรรมต่ำ K-level 1 หรือ 2 ด้วยพลังงานปลดปล่อย(Return Energy)ที่เหมาะสม แนวคิด 2 แนวทางได้รับการต่อยอดมาสู่การออกแบบเท้าเทียม งานชิ้นแรกคือเท้าเทียมโมเดล A ใช้สปริงก้นหอย 2 ชิ้นทำหน้าที่เป็นข้อเท้า ชิ้นหนึ่งสำหรับการกระดกเท้าขึ้น(Dorsiflexion)ส่วนอีกชิ้นทำหน้าที่กระดกเท้าลง(Plantarflexion) แต่ละชิ้นจะมีช่องสล็อตสำหรับสอดแท่งพินที่มีส่วนในการปรับความแข็งสปริงเชิงมุม เท้าเทียมได้รับการพัฒนาและจำลองการทำงานด้วยโปรแกรมวิธีการทางไฟไนต์เอลิเมนต์ ผลที่ได้คือสามารถปรับความแข็งสปริงได้ในช่วงกว้าง อย่างไรก็ตามเกิดความเค้นสูงบริเวณสปริงทั้งสอง รวมถึงขนาดของเท้าเทียมที่ใหญ่เกินกว่าจะสวมเข้ายางหุ้มเท้าได้ ถัดมาจึงได้ทำการออกแบบเท้าเทียมโมเดล B ที่ใช้การปรับความแข็งสปริงเชิงเส้นของส่วนForefootและHeel โดยมีชิ้นStopperคั่นระหว่าง Leaf springกับForefoot และมีStopperอีกชิ้นคั่นระหว่างLeaf springกับHeel การเปลี่ยนตำแหน่งStopperหมายถึงการปรับความแข็งสปริงไปด้วย ด้วยวิธีการประมวลผลคำนวณเช่นเดียวโมเดลก่อนหน้านี้ ผลลัพธ์ที่ได้คือช่วงความแข็งสปริงที่ปรับได้น่าพึงพาใจและความเค้นมีค่าต่ำบนชิ้นงานที่งอตัวได้ พลังงานสะสมต่ำ(Storage Energy)ในระดับความแข็งสปริงสูง เหมาะกับผู้พิการระดับกิจกรรมต่ำ K-level 1 และ 2 นอกจากนี้แล้วยังมีแนวโน้มสวมเข้าเท้ายางได้ ด้วยเหตุนี้เท้าเทียมโมเดล B จึงได้ถูกเลือกให้มาดำเนินการผลิต หลังจากทำการผลิตเท้าเทียมโมเดล B จึงได้ทำการทดสอบทางกลเพื่อตรวจสอบความปลอดภัยที่แรงกระทำปกติ และเมื่อนำไปเปรียบเทียบกับเท้าเทียมที่ขายเชิงพาณิชย์ พบกว่าเท้าเทียมโมเดล B มีค่าความแข็งสปริงเชิงเส้นครอบคลุมกลุ่มเท้าเทียมดังกล่าวที่มีขนาดเดียวกัน และมีค่าใกล้เคียงเท้าเทียมSACHและSingle Axis ในการทดสอบการใช้งานจริง ได้อาสาสมัครผู้พิการขาขาดระดับล่างข้างเดียว 1 คนมาทดลองเดินด้วยเท้าเทียมโมเดล B พร้อมลองปรับค่าความแข็งสปริง จากผลการทดสอบได้ว่ากลไกสามารถทำงานได้ และผู้พิการสามารถเลือกความแข็งสปริงที่เหมาะสมกับตนเองได้ สำหรับงานวิจัยในอนาคต มีความจำเป็นยิ่งทีต้องพัฒนาให้มีความคงทนมากยิ่งขึ้น


Prediction Of Lncrna-Protein Interactions Based On Deep Learning Model, Natsuda Navamajiti Jan 2019

Prediction Of Lncrna-Protein Interactions Based On Deep Learning Model, Natsuda Navamajiti

Chulalongkorn University Theses and Dissertations (Chula ETD)

One main function of long non-coding RNAs (lncRNAs) is to act as a scaffold facilitating multiple proteins to form complexes. Most of available prediction models for protein-RNA interactions, however, were proposed as a binary classifier, which limited on predicting the interaction between the non-coding RNAs and each individual RNA-binding protein (RBP). Hence, to predict if a lncRNA is acting as a scaffold, we consider this problem as a multiclass multilabel classification problem. To solve this problem, the high confident CLIP-seq data were selected from the POSTAR2 database with an augmentation of the data for the RBP classes with a small …


Msg-Fast: Metagenomic Shotgun Data Fast Annotation Using Microbial Gene Catalogs, Stuart M. Brown, Hao Chen, Yuhan Hao, Bobby P. Laungani, Thahmina A. Ali, Changsu Dong, Carlos Lijeron, Baekdoo Kim, Claudia Wultsch, Zhiheng Pei, Konstantinos Krampis Jan 2019

Msg-Fast: Metagenomic Shotgun Data Fast Annotation Using Microbial Gene Catalogs, Stuart M. Brown, Hao Chen, Yuhan Hao, Bobby P. Laungani, Thahmina A. Ali, Changsu Dong, Carlos Lijeron, Baekdoo Kim, Claudia Wultsch, Zhiheng Pei, Konstantinos Krampis

Publications and Research

Background: Current methods used for annotating metagenomics shotgun sequencing (MGS) data rely on a computationally intensive and low-stringency approach of mapping each read to a generic database of proteins or reference microbial genomes.

Results: We developed MGS-Fast, an analysis approach for shotgun whole-genome metagenomic data utilizing Bowtie2 DNA-DNA alignment of reads that is an alternative to using the integrated catalog of reference genes database of well-annotated genes compiled from human microbiome data. This method is rapid and provides high-stringency matches (>90% DNA sequence identity) of the metagenomics reads to genes with annotated functions. We demonstrate the use of this …


The Role Of Kras In Mechanosensing In Non-Small Cell Lung Cancer, Krista M. Powell Jan 2019

The Role Of Kras In Mechanosensing In Non-Small Cell Lung Cancer, Krista M. Powell

Theses and Dissertations

Lung cancer is the number one cause of cancer related death worldwide, with more than 1.6 million fatalities each year. Non-small cell lung cancer (NSCLC) accounts for 80-85% of all lung cancers, with KRAS being one of the most prevalent oncogenic driver mutations. Therapeutic approaches for KRAS-mutated NSCLC have been extensively explored due to the US National Cancer Institute RAS Initiative, but methods of directly targeting KRAS or downstream effectors, such as MEK, still have poor results. Previous reports have shown that KRAS-mutated NSCLC activate distinct receptor tyrosine kinases (RTKs) depending on the epithelial or mesenchymal state. Epithelial-to-mesenchymal transition (EMT) …


A Computational Assessment Of Lisfranc Injuries And Their Surgical Repairs, Michael Perez Jan 2019

A Computational Assessment Of Lisfranc Injuries And Their Surgical Repairs, Michael Perez

Theses and Dissertations

While Lisfranc injuries in the mid foot are less common than other ankle and mid foot injuries, they pose challenges in both properly identifying them and treating them. When Lisfranc injuries are ligamentous and do not include obvious fractures, they are very challenging for clinicians to identify unless weight bearing radiographs are used. The result is that 20%-40% of Lisfranc injuries are missed in the initial evaluation. Even when injuries are correctly identified the outcomes of surgical procedures remain poor. Existing literature has compared the different surgical procedures but has not had a standard approach or procedures across studies. This …


The Role Of The Mechanical Environment On Cd117+ Endothelial Cell Angiogenesis, Patrick Link Jan 2019

The Role Of The Mechanical Environment On Cd117+ Endothelial Cell Angiogenesis, Patrick Link

Theses and Dissertations

Angiogenesis is a complex process coordinating cell migration, proliferation, and lumen formation. Changes to the microenvironment regulate angiogenesis through mechanotransduction and cytokine signals. In pulmonary hypertension, something in the process becomes abnormal, resulting in changes to the microenvironment and the formation of a glomerulus of dysfunctional capillaries, called a plexiform lesion. Endothelial cells, expressing CD117 (CD117+ EC clones) increase in the plexiform lesions of pulmonary hypertension, independent of pro-angiogenic VEGF signaling. We hypothesize that the mechanical environment and the macromolecular composition of the extracellular matrix, both, contribute to the aberrant angiogenesis. When we changed the mechanical environment, we changed the …


Engineering The Alveolar Gas Exchange Barrier With Extracellular Matrix Coatings For Bioengineered Lungs, Bethany M. Young Jan 2019

Engineering The Alveolar Gas Exchange Barrier With Extracellular Matrix Coatings For Bioengineered Lungs, Bethany M. Young

Theses and Dissertations

Lower respiratory diseases are currently the third leading cause of death worldwide. For many end-stage patients with these diseases, there is no cure and a shortage of donor organs available for transplant. A promising solution is to design regenerative scaffolds or complete bioengineered lungs, using decellularized lung tissues as a template for regeneration. Recent advances in the field have made significant strides towards developing a transplantable lung. However, the current technology has not produced a functional lung for in vivo transplant due to immature gas exchange barriers. The mechanisms driving alveolar barrier maturation and role that extracellular matrix (ECM) plays …


Eralpha Isoforms Modulate The Tumorigenicity Of 24r,25(Oh)2d3 In Estrogen-Responsive Cancer, Anjali Verma Jan 2019

Eralpha Isoforms Modulate The Tumorigenicity Of 24r,25(Oh)2d3 In Estrogen-Responsive Cancer, Anjali Verma

Theses and Dissertations

Over 200,000 cases of breast cancer are diagnosed every year. Nearly 20% of these patients supplement their diets with some form of vitamin D. This high frequency of vitamin D supplement use may be due in part to research suggesting that cancer patients with higher serum vitamin D3 levels have better prognoses than patients with low serum vitamin D3. However, double-blind clinical trials on the efficacy of vitamin D3 supplementation in breast cancer have been inconclusive. A recent meta-analysis showed evidence of reduced cancer recurrence in patients taking vitamin D3 supplements who had ‘estrogen receptor positive’ …


Mechanochemical Regulation Of Epithelial Tissue Remodeling: A Multiscale Computational Model Of The Epithelial-Mesenchymal Transition Program, Lewis Scott Jan 2019

Mechanochemical Regulation Of Epithelial Tissue Remodeling: A Multiscale Computational Model Of The Epithelial-Mesenchymal Transition Program, Lewis Scott

Theses and Dissertations

Epithelial-mesenchymal transition (EMT) regulates the cellular processes of migration, growth, and proliferation - as well as the collective cellular process of tissue remodeling - in response to mechanical and chemical stimuli in the cellular microenvironment. Cells of the epithelium form cell-cell junctions with adjacent cells to function as a barrier between the body and its environment. By distributing localized stress throughout the tissue, this mechanical coupling between cells maintains tensional homeostasis in epithelial tissue structures and provides positional information for regulating cellular processes. Whereas in vitro and in vivo models fail to capture the complex interconnectedness of EMT-associated signaling networks, …


Development Of An Eye Movement Based Predictive Model For Discrimination Of Parkinson's Disease From Other Parkinsonisms And Controls, Mary Anisa Kannan Jan 2019

Development Of An Eye Movement Based Predictive Model For Discrimination Of Parkinson's Disease From Other Parkinsonisms And Controls, Mary Anisa Kannan

Theses and Dissertations

Purpose: Due to the neurological aspects of Parkinson’s Disease (PD) and the sensitivity of eye movements to neurological issues, eye tracking has the potential to be an objective biomarker with higher accuracy in diagnosis than current clinical standards. Currently when PD is diagnosed clinically, there is an accuracy of 74% when diagnosed by a general practitioner and 82% when diagnosed by a movement disorder specialist. This study was designed to: 1. Assess eye movements as a potential biomarker for Parkinson’s Disease. 2. Determine if eye movements can distinguish between Parkinson’s Disease and commonly confounded movement disorders with parkinsonian symptoms. 3. …


Assessment Of Access Methods For Mobile Maps For Individuals Who Are Blind Or Visually Impaired, David Parker Jan 2019

Assessment Of Access Methods For Mobile Maps For Individuals Who Are Blind Or Visually Impaired, David Parker

Theses and Dissertations

When people go to a mall, museums, or other such locations they tend to rely on maps to find their way around. However, for people who are blind or visually impaired (BVI) maps are not easily accessible and they depend on other means, such as a guide, to get around. Research has only just begun to investigate providing maps for people who are BVI on touch screen devices. Many different types of feedback have been used: audio (sound), tactile (touch), audio-tactile, and multitouch. Some research has been conducted on the benefit of using multiple fingers (multitouch) and has found conflicting …


Aptamer Functionalized Zinc Oxide Field Effect Transistors For Odor Detection, Michael D. Aldridge Jan 2019

Aptamer Functionalized Zinc Oxide Field Effect Transistors For Odor Detection, Michael D. Aldridge

Graduate Theses, Dissertations, and Problem Reports (ETD)

Odor detection and identification are complex processes, and tasks that currently only animals do well. There is a pressing need for an electronic nose, or eNose, with good sensitivity, selectivity, and speed that mimics that ability. Food quality control operations, environmental sensing, occupational safety, and the defense sectors all require systems that can rapidly and reliably detect trace levels of volatile organic compounds. The goal of this work is to create a biologically inspired device which can accurately detect and identify odors at concentrations consistent with the most sensitive biological systems.

In order to mimic a natural olfactory system, we …


Textured Contact Lens Based Iris Presentation Attack In Uncontrolled Environment, Daksha Yadav Jan 2019

Textured Contact Lens Based Iris Presentation Attack In Uncontrolled Environment, Daksha Yadav

Graduate Theses, Dissertations, and Problem Reports (ETD)

The widespread use of smartphones has spurred the research in mobile iris devices. Due to their convenience, these mobile devices are also utilized in unconstrained outdoor conditions. At the same time, iris recognition in the visible spectrum has developed into an active area of research. These scenarios have necessitated the development of reliable iris recognition algorithms for such an uncontrolled environment. Additionally, iris presentation attacks such as textured contact lens pose a major challenge to current iris recognition systems.

Motivated by these factors, in this thesis, a detailed analysis of the effect of textured contact lenses on iris recognition in …


A Biomimetic Approach To Controlling Restorative Robotics, Matthew T. Boots Jan 2019

A Biomimetic Approach To Controlling Restorative Robotics, Matthew T. Boots

Graduate Theses, Dissertations, and Problem Reports (ETD)

Movement is the only way a person can interact with the world around them. When trauma to the neuromuscular systems disrupts the control of movement, quality of life suffers. To restore limb functionality, active robotic interventions and/or rehabilitation are required. Unfortunately, the primary obstacle in a person’s recovery is the limited robustness of the human-machine interfaces. Current systems rely on control approaches that rely on the person to learn how the system works instead of the system being more intuitive and working with the person naturally. My research goal is to design intuitive control mechanisms based on biological processes termed …


Spatiotemporal Modeling And Model Restructuration Approaches In Studies Of Intracellular Signalling Pathways, Md Shahinuzzaman Jan 2019

Spatiotemporal Modeling And Model Restructuration Approaches In Studies Of Intracellular Signalling Pathways, Md Shahinuzzaman

Doctoral Dissertations

"The main focus of the research is to understand the complex phenomena of cell transduction pathways and cell biology in a single cell. Mathematical modeling and experimental evaluation are widely used approaches for this kind of research. Firstly, A multiscale framework for protein-protein interaction has been established using Brownian dynamics algorithm. Sit specific feature, steric collision, diffusion, co-localization and complex formation with time and space has been included in this spatial modeling framework. By implementation of the time adaptive feature in this framework, the computation time reduces in an order of magnitude compared with traditional modeling framework. This multiscale Brownian …


Applications Of Machine Learning In Nuclear Imaging And Radiation Detection, Shaikat Mahmood Galib Jan 2019

Applications Of Machine Learning In Nuclear Imaging And Radiation Detection, Shaikat Mahmood Galib

Doctoral Dissertations

"The main focus of this work is to use machine learning and data mining techniques to address some challenging problems that arise from nuclear data. Specifically, two problem areas are discussed: nuclear imaging and radiation detection. The techniques to approach these problems are primarily based on a variant of Artificial Neural Network (ANN) called Convolutional Neural Network (CNN), which is one of the most popular forms of 'deep learning' technique.

The first problem is about interpreting and analyzing 3D medical radiation images automatically. A method is developed to identify and quantify deformable image registration (DIR) errors from lung CT scans …


Development Of An Impedance-Controlled Hot Snare Polypectomy Device To Minimize Tissue Damage, Curtislee Thornton Jan 2019

Development Of An Impedance-Controlled Hot Snare Polypectomy Device To Minimize Tissue Damage, Curtislee Thornton

College of Graduate Studies: Theses & Dissertations

This study explores the ability to measure the changing impedance, ex vivo, of a porcine colon sample while undergoing a high-frequency alternating current from an Olympus PSD-30 electrosurgical unit and stop the applied current before excessive tissue damage ensues. The causes of the thermal damage are first examined, followed by the construction and testing of the impedance-controlled feedback device. Perforation was observed to occur when the impedance of the tissue sample increased by 25% or more. Using this information, the device was tested for five power settings ranging from 10W-50W. In each trial, the feedback device stopped the applied current …


Ct Automated Exposure Control Using A Generalized Detectability Index, P. Khobragade, Franco Rupcich, Jiahua Fan, Dominic J. Crotty, Naveen M. Kulkarni, Stacy D. O'Connor, W. Dennis Foley, Taly Gilat Schmidt Jan 2019

Ct Automated Exposure Control Using A Generalized Detectability Index, P. Khobragade, Franco Rupcich, Jiahua Fan, Dominic J. Crotty, Naveen M. Kulkarni, Stacy D. O'Connor, W. Dennis Foley, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose

Identifying an appropriate tube current setting can be challenging when using iterative reconstruction due to the varying relationship between spatial resolution, contrast, noise, and dose across different algorithms. This study developed and investigated the application of a generalized detectability index (d'gen) to determine the noise parameter to input to existing automated exposure control (AEC) systems to provide consistent image quality (IQ) across different reconstruction approaches.

Methods

This study proposes a task‐based automated exposure control (AEC) method using a generalized detectability index (d'gen). The proposed method leverages existing AEC methods that are based on a prescribed …


Spatial And Temporal Influences On Discrimination Of Vibrotactile Stimuli On The Arm, Valay Shah, Maura Casadio, Robert A. Scheidt, Leigh A. Mrotek Jan 2019

Spatial And Temporal Influences On Discrimination Of Vibrotactile Stimuli On The Arm, Valay Shah, Maura Casadio, Robert A. Scheidt, Leigh A. Mrotek

Biomedical Engineering Faculty Research and Publications

Body–machine interfaces (BMIs) provide a non-invasive way to control devices. Vibrotactile stimulation has been used by BMIs to provide performance feedback to the user, thereby reducing visual demands. To advance the goal of developing a compact, multivariate vibrotactile display for BMIs, we performed two psychophysical experiments to determine the acuity of vibrotactile perception across the arm. The first experiment assessed vibration intensity discrimination of sequentially presented stimuli within four dermatomes of the arm (C5, C7, C8, and T1) and on the ulnar head. The second experiment compared vibration intensity discrimination when pairs of vibrotactile stimuli were presented simultaneously vs. sequentially …


Attitudes Toward Failure In Capstone Design Projects, Jay R. Goldberg Jan 2019

Attitudes Toward Failure In Capstone Design Projects, Jay R. Goldberg

Biomedical Engineering Faculty Research and Publications

While working in industry during the 1980s and 1990s, project failures were to be avoided at all costs. For engineers in the medical device industry, these failures could be in the form of: 1) an idea for a new product or feature that eventually failed due to technical infeasibility, regulatory hurdles, lack of market interest, or difficulty in manufacturing; 2) a prototype that did not function as required; or 3) an animal or human clinical study that yielded poor results. They typically resulted in significant project delays, wasted time and money, and lost revenues, and often led to lower raises, …


The Relative Contribution Of Fixation Features, Activity, And Tibiofemoral Conformity On Initial Stability Of Cementless Tibial Trays, James Sullivan Deacy Jan 2019

The Relative Contribution Of Fixation Features, Activity, And Tibiofemoral Conformity On Initial Stability Of Cementless Tibial Trays, James Sullivan Deacy

Electronic Theses and Dissertations

Initial stability of cementless total knee replacements (TKR) is critical to implant success as excessive motion between the bone and implant prevents bony ingrowth that is critical to the long-term survivability of cementless implants. Prior studies have shown that excessive micromotion causes fibrous tissue growth instead of beneficial bony growth. There are many factors that influence initial stability including the design of the tibial tray and the tibiofemoral articulations. Understanding the impacts of these design features on micromotion between the bone and implants is crucial to improving the performance of cementless TKR. Prior studies only tested for the effect of …


Nanostructured Materials For Food Applications: Spectroscopy, Microscopy And Physical Properties, Shubham Sharma, Swana Jaiswal, Brendan Duffy, Amit Jaiswal Jan 2019

Nanostructured Materials For Food Applications: Spectroscopy, Microscopy And Physical Properties, Shubham Sharma, Swana Jaiswal, Brendan Duffy, Amit Jaiswal

Articles

Nanotechnology deals with the matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, the thermal stability of the nanoparticle, and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterize the size, shape, and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning …


Design And Development Of Artificial Spinal Ligaments For Paediatric Synthetic Spine, Nor Amalina Muhayudin, Khairul Salleh Basaruddin, Fiona Mcevoy, Anthony Tansey Jan 2019

Design And Development Of Artificial Spinal Ligaments For Paediatric Synthetic Spine, Nor Amalina Muhayudin, Khairul Salleh Basaruddin, Fiona Mcevoy, Anthony Tansey

Articles

A synthetic spine is a model fabricated from artificial materials consisting of the vertebrae, intervertebral discs and ligaments for spinal testing. The synthetic spine overcomes many difficulties associated with biological specimens such as handling, biohazard concerns, high costs, and limited availability of specimens, quality and large inter-specimen variability. This paper presents the design and development of spinal ligaments to mimic the stiffness of the paediatric ligaments for use in the synthetic spine. Spinal ligaments are uniaxial structures in the spine that carry tensile loads along the direction of the fibres. Early in the research, silicone materials were used to cover …


Magnetic Composite Biomaterials For Neural Regeneration, Jessica L. Funnell, Bailey Balouch, Ryan J. Gilbert Jan 2019

Magnetic Composite Biomaterials For Neural Regeneration, Jessica L. Funnell, Bailey Balouch, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Nervous system damage caused by physical trauma or degenerative diseases can result in loss of sensory and motor function for patients. Biomaterial interventions have shown promise in animal studies, providing contact guidance for extending neurites or sustained release of various drugs and growth factors; however, these approaches often target only one aspect of the regeneration process. More recent studies investigate hybrid approaches, creating complex materials that can reduce inflammation or provide neuroprotection in addition to stimulating growth and regeneration. Magnetic materials have shown promise in this field, as they can be manipulated non-invasively, are easily functionalized, and can be used …


Spatial Fingerprinting Of Biogenic And Anthropogenic Volatile Organic Compounds In An Arid Unsaturated Zone, Christopher T. Green, Wentai Luo, Christopher H. Conaway, Karl B. Haase, Ronald J. Baker Jan 2019

Spatial Fingerprinting Of Biogenic And Anthropogenic Volatile Organic Compounds In An Arid Unsaturated Zone, Christopher T. Green, Wentai Luo, Christopher H. Conaway, Karl B. Haase, Ronald J. Baker

Chemistry Faculty Publications and Presentations

Subsurface volatile organic compounds (VOCs) can pose risks to human and environmental health and mediate biological processes. Volatile organic compounds have both anthropogenic and biogenic origins, but the relative importance of these sources has not been explored in subsurface environments. This study synthesized 17 yr of VOC data from the Amargosa Desert Research Site in Nevada with the goal of improving understanding of spatial and temporal variations that distinguish sources of VOCs from a landfill and from ambient sources including biogenic VOCs (bVOCs). Gas samples were collected from 1999 to 2016 from an array of shallow sample points (0.5- and …


Well-Ordered Mesoporous Silica And Bioactive Glasses: Promise For Improved Hemostasis, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Mark R. Towler Jan 2019

Well-Ordered Mesoporous Silica And Bioactive Glasses: Promise For Improved Hemostasis, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediate control of uncontrolled bleeding and infection are essential for saving lives in both combat and civilian arenas. Inorganic well-ordered mesoporous silica and bioactive glasses have recently shown great promise for accelerating hemostasis and infection control. However, to date, there has been no comprehensive report assessing their specific mechanism of action in accelerating the hemostasis process and exerting an antibacterial effect. After providing a brief overview of the hemostasis process, this review presents a critical overview of the recently developed inorganic mesoporous silica and bioactive glass-based materials proposed for hemostatic clinical applications and specifically investigates their unique characteristics that render …


Cardiac Regenerative Medicine: Insights From Healthy And Diseased Engineered Tissues, Pamela Grace Hitscherich Dec 2018

Cardiac Regenerative Medicine: Insights From Healthy And Diseased Engineered Tissues, Pamela Grace Hitscherich

Dissertations

Cardiovascular disease remains the leading cause of mortality in the United States. Current tissue engineering approaches have fallen short of promoting fully functional cardiovascular cells and the post-myocardial infarction microenvironment is still not well understood. These gaps in knowledge are addressed in this dissertation through the development of in vitro engineered cardiac tissues using electroactive materials to enhance the differentiation of pluripotent stem cell derived cardiomyocytes and through the development of in vitro myocardial inflammation models dedicated to understanding cardiomyocytes and macrophages interactions.

Specifically, piezoelectric poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) supports the attachment and survival of mouse embryonic stem cell derived …


Gait Rehabilitation Using Functional Electrical Stimulation Induces Changes In Ankle Muscle Coordination In Stroke Survivors: A Preliminary Study, Jessica L. Allen, Lena H. Ting, Trisha M. Kesar Dec 2018

Gait Rehabilitation Using Functional Electrical Stimulation Induces Changes In Ankle Muscle Coordination In Stroke Survivors: A Preliminary Study, Jessica L. Allen, Lena H. Ting, Trisha M. Kesar

Faculty & Staff Scholarship

No abstract provided.


Quantifying Mg 2+ Binding To Ssdna Oligomers: A Self-Consistent Field Theory Study At Varying Ionic Strengths And Grafting Densities, Merina Jahan, Mark J. Uline Dec 2018

Quantifying Mg 2+ Binding To Ssdna Oligomers: A Self-Consistent Field Theory Study At Varying Ionic Strengths And Grafting Densities, Merina Jahan, Mark J. Uline

Faculty Publications

The performance of aptamer-based biosensors is crucially impacted by their interactions with physiological metal ions, which can alter their structures and chemical properties. Therefore, elucidating the nature of these interactions carries the utmost importance in the robust design of highly efficient biosensors. We investigated Mg 2+ binding to varying sequences of polymers to capture the effects of ionic strength and grafting density on ion binding and molecular reorganization of the polymer layer. The polymers are modeled as ssDNA aptamers using a self-consistent field theory, which accounts for non-covalent ion binding by integrating experimentally-derived binding constants. Our model captures the typical …


Effect Of Strong Electrolyte Containing Gelling Aids On The Sol-Gel Transition Temperature Of Hypromellose 2910, Elnaz Sadeghi Dec 2018

Effect Of Strong Electrolyte Containing Gelling Aids On The Sol-Gel Transition Temperature Of Hypromellose 2910, Elnaz Sadeghi

Biomedical Engineering ETDs

Hypromellose, or hydroxypropyl methylcellulose (HPMC) - has been widely used for biomedical and pharmaceutical applications due to its advantages, including that it is modifiable in terms of viscosity, and it has the ability to form thermally reversible hydrogels. The thermal gelation temperature (TGel) of a given HPMC solution strongly depends on its characteristic grade and the solution concentration. Applying certain additives can modify the TGel even further; depending on their nature and concentration. With the addition of said additives, a lower or higher TGel can be obtained. For example, the addition of sodium chloride (NaCl) reduces …