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Monitoring Changes In Hemodynamics Following Optogenetic Stimulation, Seth Thomas Frye 2014 University of Wisconsin Milwaukee

Monitoring Changes In Hemodynamics Following Optogenetic Stimulation, Seth Thomas Frye

Theses and Dissertations

The brain is composed of billions of neurons, all of which connected through a vast network. After years of study and applications of different technologies and techniques, there are still more questions than answers when it comes to the fundamental functions of the brain. This project aims to provide a new tool which can be used to gain a better understanding of the fundamental mechanisms that govern neurological processes inside the brain. In order for neural networks to operate, blood has to be supplied through neighboring blood vessels. As such, the increase or decrease in the blood supply has been ...


Injectable, Magnetic Plum Pudding Hydrogel Composites For Controlled Pulsatile Drug Release, Danielle Maitland 2014 McMaster University

Injectable, Magnetic Plum Pudding Hydrogel Composites For Controlled Pulsatile Drug Release, Danielle Maitland

Open Access Dissertations and Theses

Injectable, in-situ gelling magnetic plum pudding hydrogel composites were fabricated by entrapping superparamagnetic iron oxide nanoparticles (SPIONs) and thermosensitive N-isopropylacrylamide (NIPAM)-co–N-isopropylmethacrylamide (NIPMAM) microgels in a pNIPAM-hydrazide/carbohydrate-aldehyde hydrogel matrix. The resulting composites exhibited significant, repeatable pulsatile release of 4 kDa FITC-dextran upon exposure to an alternating magnetic field. The pulsatile release from the composites could be controlled by altering the volume phase transition temperatures of the microgel particles (with VPTTs over 37°C corresponding to improved pulsatile release) and changing the microgel content of the composite (with higher microgel content corresponding to higher pulsatile release). By changing the ...


A Multi-Well Concentration Gradient Drug Delivery Microfluidic Device For High-Content And High-Throughput Screening, Michael M. Nelson 2014 McMaster University

A Multi-Well Concentration Gradient Drug Delivery Microfluidic Device For High-Content And High-Throughput Screening, Michael M. Nelson

Open Access Dissertations and Theses

A microfluidic device capable of drug delivery to multiple wells in a concentration gradient was designed for automated high content and high throughput screening. The design was proposed to utilize a nanoporous polycarbonate membrane to spatially and temporally control drug dosage from the microchannels below to the wells above. Microchannels were to hold to the drugs or reagents, while wells were to culture cells. An array of 16 wells was to fit in the equivalent area of a single well of a 96 well plate. Two simpler devices were created to validate electrokinetic drug delivery to a single well and ...


Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu 2014 University of Nebraska - Lincoln

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Mechanical & Materials Engineering Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by ...


Design And Assessment Of An Experimental Test Setup For Use In Studies On The Vibrational Response Of The Head To Impact, Claudia M. Blandford 2014 Western University

Design And Assessment Of An Experimental Test Setup For Use In Studies On The Vibrational Response Of The Head To Impact, Claudia M. Blandford

University of Western Ontario - Electronic Thesis and Dissertation Repository

With the mortality, disability and socioeconomic costs associated with head injury, head impact biomechanics is important to developing injury criterions and safety tolerances. However, the current state of knowledge is contradictory and vague. This thesis will contribute to research done on the vibrational response of the head to impact by discussing two studies. The first will describe the design, implementation and validation of a head impactor setup specific for the study of the frequency response of the skull. An impactor capable of producing sub-5ms duration, sub-fracture impacts was successfully designed. The apparatus was validated by comparing the results of a ...


Design And Development Of A Miniature In Vivo Surgical Robot With Distributed Motor Control For Laparoendoscopic Single-Site Surgery, Eric J. Markvicka 2014 University of Nebraska - Lincoln

Design And Development Of A Miniature In Vivo Surgical Robot With Distributed Motor Control For Laparoendoscopic Single-Site Surgery, Eric J. Markvicka

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Paradigm shifts in invasiveness, recovery time, cosmesis, and cost have been seen within the field of general surgery through major advances in surgical technology. Some of the most advanced types of general surgery now include Minimally Invasive Surgery (MIS), LaparoEndoscopic Single-Site (LESS) surgery, and Natural Orifice Translumenal Endoscopic Surgery (NOTES). One of the newest and rapidly developing catalysts is robotic platforms. Such platforms have improved ergonomics and control, increased workspace and dexterity, and have surpassed the efficacy of many non-robotic platforms such as traditional laparoscopic surgical tools. This thesis presents the design and development of a four-degree-of-freedom (4- DOF) miniature ...


Improvements To Uhmwpe, Brooke McKelvogue 2014 Minnesota State University, Mankato

Improvements To Uhmwpe, Brooke Mckelvogue

Journal of Undergraduate Research at Minnesota State University, Mankato

Ultra high molecular weight polyethylene (UHMWPE) is a material used in artificial implants for articular joint replacements. However, these implants have a limited lifespan in which the patient will be pain-free due to the wear of the UHMWPE components. Recently crosslinking, or exposing the material to radiation, has been used to extend the wear resistance of UHMWPE. Crosslinking introduces another set of drawbacks; mainly the reduction of the fracture toughness of UHMWPE and the generation of free radicals, which leave the polymer vulnerable to damage from oxidation. Currently, research is being conducted on other methods to increase the wear resistance ...


Computational Model Of A Left Ventricle: Showing The Effects Of Inertia On Cardiac Dyssynchrony, Andrew McNally, Matthew Korpela, Erin Lamke, Matthew Hudson 2014 Minnesota State University, Mankato

Computational Model Of A Left Ventricle: Showing The Effects Of Inertia On Cardiac Dyssynchrony, Andrew Mcnally, Matthew Korpela, Erin Lamke, Matthew Hudson

Journal of Undergraduate Research at Minnesota State University, Mankato

In an effort to research heart failure, a leading cause of death in the industrialized world, this research team has developed a segmented lumped parameter model of the left ventricle. The computations model developed focuses on dyssynchrony, a heart condition where some regions of the heart vary significantly in properties like internal muscle resistance, mass, or elastance. Inertial effects are often assumed as negligible by cardiovascular models. One primary function of this model is to investigate inertial effects as they relate to mechanical cardiac dyssynchrony. An added dimension of this analysis is to observe the thermodynamics of the cardiac cycle ...


Rapid Segmentation Techniques For Cardiac And Neuroimage Analysis, Martin Rajchl 2014 Western University

Rapid Segmentation Techniques For Cardiac And Neuroimage Analysis, Martin Rajchl

University of Western Ontario - Electronic Thesis and Dissertation Repository

Recent technological advances in medical imaging have allowed for the quick acquisition of highly resolved data to aid in diagnosis and characterization of diseases or to guide interventions. In order to to be integrated into a clinical work flow, accurate and robust methods of analysis must be developed which manage this increase in data. Recent improvements in in- expensive commercially available graphics hardware and General-Purpose Programming on Graphics Processing Units (GPGPU) have allowed for many large scale data analysis problems to be addressed in meaningful time and will continue to as parallel computing technology improves. In this thesis we propose ...


Laser-Assisted Surface Modification Of Hybrid Hydrogels To Prevent Bacterial Contamination And Protein Fouling, Guobang Huang 2014 Western University

Laser-Assisted Surface Modification Of Hybrid Hydrogels To Prevent Bacterial Contamination And Protein Fouling, Guobang Huang

University of Western Ontario - Electronic Thesis and Dissertation Repository

Silicone hydrogels have been extensively studied in the fields of contact lenses, tissue engineering, and drug delivery due to their good biocompatibility, high oxygen permeability, and proper light transmission. However, their applications in biomedical devices are limited by protein adsorption and bacterial contamination because of the hydrophobic surface of silicone, which will cause more irreversible protein adsorption. Several physical methods can be applied to create a hydrophilic surface on hydrogels, such as spin coating, physical vapor deposition, dip coating, drop casting, etc. Compared to the conventional methods, the matrix assisted pulsed laser evaporation (MAPLE) is suitable to produce biopolymer/polymer ...


Fluid Powered Miniature In-Vivo Robots For Minimally Invasive Surgery (Mis), Abolfazl Pourghodrat 2014 University of Nebraska - Lincoln

Fluid Powered Miniature In-Vivo Robots For Minimally Invasive Surgery (Mis), Abolfazl Pourghodrat

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Minimizing the invasiveness of surgery is believed to improve patient outcomes. Bleeding, infection, and pain are major concerns in surgery afflicting patients for decades. Minimally invasive techniques have come into play to reduce these concerns and smooth the evolution of abdominal surgery to a scarless process where nearly all surgeries can be performed without a skin incision. Technology continually advances the frontier of development of novel surgical devices to implement less invasive surgical techniques.

Fusion of robotics and Minimally Invasive Surgery (MIS) has created new opportunities to develop diagnostic and therapeutic tools. Surgical robotics is advancing from externally actuated systems ...


Curcumin-Loaded Magnetic Nanoaggregates Conjugated With Folic Acid For Targeted Cancer Treatment, Melessa Salem 2014 Western University

Curcumin-Loaded Magnetic Nanoaggregates Conjugated With Folic Acid For Targeted Cancer Treatment, Melessa Salem

University of Western Ontario - Electronic Thesis and Dissertation Repository

Cancer has been, and still remains, one of the most complicated diseases to treat. As a result of the side effects experienced from current cancer treatment methods, there has been a growing interest in the development of targeted drug delivery systems that can destroy cancer cells, but render healthy tissue unharmed. To address this challenge, magnetite nanoaggregates were synthesized through the precipitation of iron oxide in the presence of polymers, conjugated with folic acid for folate targeting, and loaded with curcumin for cancer treatment. The resulting magnetite nanoparticles were 10 – 20 nm in size and the aggregates formed varied in ...


Some Analytic And Finite Element Solutions Of The Graphene Euler Beam, Dongming Wei 2014 University of New Orleans

Some Analytic And Finite Element Solutions Of The Graphene Euler Beam, Dongming Wei

Dongming Wei

No abstract provided.


Rapid Prototyping Amphiphilic Polymer/Hydroxyapatite Composite Scaffolds With Hydration-Induced Self-Fixation Behavior, Artem B. Kutikov, Anvesh Gurijala, Jie Song 2014 University of Massachusetts Medical School

Rapid Prototyping Amphiphilic Polymer/Hydroxyapatite Composite Scaffolds With Hydration-Induced Self-Fixation Behavior, Artem B. Kutikov, Anvesh Gurijala, Jie Song

GSBS Student Publications

Two major factors hampering the broad use of rapid prototyped biomaterials for tissue engineering applications are the requirement for custom-designed or expensive research-grade three-dimensional (3-D) printers and the limited selection of suitable thermoplastic biomaterials exhibiting physical characteristics desired for facile surgical handling and biological properties encouraging tissue integration. Properly designed thermoplastic biodegradable amphiphilic polymers can exhibit hydration-dependent hydrophilicity changes and stiffening behavior, which may be exploited to facilitate the surgical delivery/self-fixation of the scaffold within a physiological tissue environment. Compared to conventional hydrophobic polyesters, they also present significant advantages in blending with hydrophilic osteoconductive minerals with improved interfacial adhesion ...


Human Metaphase Chromosome Analysis Using Image Processing, Akila M.S Subasinghe Arachchige 2014 Western University

Human Metaphase Chromosome Analysis Using Image Processing, Akila M.S Subasinghe Arachchige

University of Western Ontario - Electronic Thesis and Dissertation Repository

Development of an effective human metaphase chromosome analysis algorithm can optimize expert time usage by increasing the efficiency of many clinical diagnosis processes. Although many methods exist in the literature, they are only applicable for limited morphological variations and are specific to the staining method used during cell preparation. They are also highly influenced by irregular chromosome boundaries as well as the presence of artifacts such as premature sister chromatid separation.

Therefore an algorithm is proposed in this research which can operate with any morphological variation of the chromosome across images from multiple staining methods. The proposed algorithm is capable ...


Functional Co-Substituted Poly[(Amino Acid Ester)Phosphazene] Biomaterials, Amanda L. Baillargeon 2014 Western University

Functional Co-Substituted Poly[(Amino Acid Ester)Phosphazene] Biomaterials, Amanda L. Baillargeon

University of Western Ontario - Electronic Thesis and Dissertation Repository

The development of new and improved biomaterials is essential for tissue engineering and regenerative medicine applications. Amino acid-based polyphosphazenes are being explored as scaffold materials for tissue engineering applications due to their non-toxic degradation products and tunable material properties. This work focuses on the synthesis of non-functional and novel functional poly[(amino acid ester)phosphazene]s using a facile method of thermal ring opening polymerization followed by one-pot room temperature substitution. The family of polyphosphazenes developed in this work is based on L-alanine (PNEAs), L-phenylalanine (PNEFs), and L-methionine (PNEMs) with L-glutamic acid imparting the functionality. Characterization of these materials demonstrated ...


Perspectives For Titanium-Derived Fillers Usage On Denture Base Composite Construction, Nidal Elshereksi 2014 SelectedWorks

Perspectives For Titanium-Derived Fillers Usage On Denture Base Composite Construction, Nidal Elshereksi

Nidal Elshereksi

Poly(methyl methacrylate) (PMMA) is an extensively used material in dentistry because of its aesthetics, processability, and reparability. However, PMMA is still far from being ideal in fulfilling the mechanical requirements of prosthesis. PMMA-based denture base polymers exhibit low fracture resistance and radiopacity behavior. Efforts to improve the mechanical and radiopacity properties of denture base materials through inclusion of silica-based fillers are ongoing. Although silane-treated siliceous fillers are commonly used, they are not sufficiently strong.They also exhibit cracks, which either cut through the glass fillers or propagate around the filler particles. This defect occurs when the dental composites are ...


Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson 2014 University of Nebraska - Lincoln

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Mechanical & Materials Engineering Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further ...


Frontal White Matter Integrity In Adults With Down Syndrome With And Without Dementia, David K. Powell, Allison Caban-Holt, Greg A. Jicha, William C. Robertson, Roberta Davis, Brian T. Gold, Frederick A. Schmitt, Elizabeth Head 2014 University of Kentucky

Frontal White Matter Integrity In Adults With Down Syndrome With And Without Dementia, David K. Powell, Allison Caban-Holt, Greg A. Jicha, William C. Robertson, Roberta Davis, Brian T. Gold, Frederick A. Schmitt, Elizabeth Head

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Adults with Down syndrome (DS) are at high risk for developing Alzheimer's disease after the age of 40 years. To detect white matter (WM) changes in the brain linked to dementia, fractional anisotropy (FA) from diffusion tensor imaging was used. We hypothesized that adults with DS without dementia (DS n = 10), DS with dementia (DSAD n = 10) and age matched non-DS subjects (CTL n = 10) would show differential levels of FA and an association with scores from the Brief Praxis Test and the Severe Impairment Battery. WM integrity differences in DS compared with CTL were found predominantly in the ...


Preliminary Test Of A Real-Time, Interactive Silent Speech Interface Based On Electromagnetic Articulograph, Jun Wang, Ashok Samal, Jordan R. Green 2014 University of Nebraska - Lincoln

Preliminary Test Of A Real-Time, Interactive Silent Speech Interface Based On Electromagnetic Articulograph, Jun Wang, Ashok Samal, Jordan R. Green

CSE Conference and Workshop Papers

A silent speech interface (SSI) maps articulatory movement data to speech output. Although still in experimental stages, silent speech interfaces hold significant potential for facilitating oral communication in persons after laryngectomy or with other severe voice impairments. Despite the recent efforts on silent speech recognition algorithm development using offline data analysis, online test of SSIs have rarely been conducted. In this paper, we present a preliminary, online test of a real-time, interactive SSI based on electromagnetic motion tracking. The SSI played back synthesized speech sounds in response to the user’s tongue and lip movements. Three English talkers participated in ...


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