Digital Commons Network^™

Aminooxy Reagents In Nanomedicine And Bioanalysis., Stephanie Mattingly

Electronic Theses and Dissertations

The development of nanomaterials as medical diagnostic and therapeutic agents is a rapidly expanding field. A brief search of the literature revealed that roughly half of all articles related to nanoparticle-based drug delivery were published after the onset of this thesis research, over the past 4 years. A few nano-based formulations have entered into clinical use, including liposomal drug formulations, protein-linked drugs, and nanoparticle-based MRI contrast agents. The chemistry that enables conjugation of a functional cargo, whether a drug, a targeting element, or a radionucleotide, to a nanocarrier is thus a critical component for development. Oximation is one of the …

Development Of A Thin-Film Porous-Microelectrode Array (P-Mea) For Electrical Stimulation Of Engineered Cardiac Tissue., Hiren Vrajlal Trada 1977-

Electronic Theses and Dissertations

Electrical stimulation has been increasingly used by research groups to enhance and increase maturation of cells in an engineered cardiac tissue (ECT). Current methods are based on using off-the-shelf wires or electrodes to deliver a stimulus voltage to the in-vitro tissue in culture medium. A major issue with this approach is the generation of byproducts in the medium due to the voltage levels required, which are typically in the range of 5V-10V. No solution currently exists that can accomplish electrical stimulation of cells in an ECT at a low voltage level. Therefore, in this study a novel, porous, thinfilm, microelectrode …

Post Fatigue Changes In The Stability Of Cervical Spine, Majed M. Zreiqat

Graduate Theses, Dissertations, and Problem Reports

Musculoskeletal disorders (MSDs) of the neck or cervical spine are a common problem in the modern workforce. An annual prevalence of 30% to 50% for neck pain among the general adult population was reported by the Task Force of Bone and Joint Decade on Neck Pain. Physical work demands, such as sustained static postures, sub-maximal repetitive arm exertions, and forceful arm exertions are consistently identified as possible risk factors for cervical spine MSDs. Most of these exertions induce neck muscle fatigue which may affect the stability of the cervical spine. A less stable spine can be both a cause and …

Development Of Biomechanical Analysis Techniques For Fatigue Of Transtibial Prosthetic Socket And Pylon Interactions, Thomas Z. Sudbury

Honors Theses

The lack of formal, engineering based information is prevalent in the prosthetic industry. Currently, very few prosthetic manufacturing companies can definitively tell their patients how long their products will last. Because of this lack of information, many amputee patients will experience failure of their transtibial prosthetic device during daily activities. One such failure occurs from the fatigue of everyday use. Fatigue failures originate from the repeated application of certain loading conditions. These repeated loads usually occur for millions of cycles before a transtibial prosthetic catastrophically fails. The purpose of this study is to develop a testing procedure and apparatus that …

Dependence Of The Abdominal Wall-Mesh Interfacial Strength On The Fixation Method For Ventral Hernia Repair, Hummad Mohammad Tasneem

Electronic Theses and Dissertations

Hernia occurrence is on the rise. The most common approach to repair today is a hernioplasty repair using a surgical mesh for permanent reinforcement after repairing the hernia defect. Different fixation techniques using materials such as tacks, staples, sutures, or adhesives are utilized to provide initial fixation until tissue ingrowth occurs. Currently, regarding ventral hernia mesh repair operations there is inadequate amount of information available regarding the efficiency of a mesh repair using adhesives. Consequently, this study compares the interface strength between mesh and tissue when mesh is fixed with either of the two following techniques: a) adhesives or b) …

A Novel Controlled Release Platform For In Situ Vascular Tissue Engineering, Joseph Thomas Patterson

Yale Medicine Thesis Digital Library

Autologous tissue engineered vascular grafts (TEVGs) are limited by graft stenosis. Small diameter TEVGs implanted as unseeded scaffolds are prone to failure by occlusive luminal proliferation of smooth muscle cells derived from endothelial precursors within a critical period of two weeks. The development, validation, and application novel platform for controlling TEVG performance by local delivery of peptide and/or small molecule therapeutic agents from the TEVG scaffold is presented with insights into the autologous TEVG biology and development.

We hypothesized that inhibition of TGF-βR1 by local delivery of SB-431542, a competitive inhibitor of ALK5/TGFβR1 signaling, is superior to systemic administration of …

Identification Of Novel Anti-Brain Tumor-Initiating Cell Compounds Using High-Throughput Screening, Garth William Strohbehn

Yale Medicine Thesis Digital Library

Glioblastoma multiforme is the most common malignant primary intracranial tumor in adults. Despite years of advances in basic science knowledge about this disease including but not limited to cellular hierarchy, genetics, and mechanisms of proliferation and spread, overall survival of patients has remained unmoved for the past fifteen years, and long-term survivors are nearly nonexistent. Barriers to improved treatment occur in the realms of engineering and drug discovery: creation of an efficient delivery vehicle and identification of novel, efficacious small molecule compounds are necessary to achieve survival benefit in this disease.

In the following thesis, I describe efforts made by …

Potential Optimal Gait Performance Of Mauch S-N-S Prosthetic Knee Configurations As Predicted By Dynamic Modeling, Chih-Hao Chien

ETD Archive

Patients with prosthetic legs routinely suffer from abnormal gait patterns which can cause health issues and eventually lower the quality of their lives. Despite the half-century advance in the technology of prosthetic knees, from the purely mechanical to microprocessor controlled systems, patient testing suggests that very little progress has been made in the quality of the kinetics and kinematics of amputee gait. Moreover, the cost of microprocessor controlled prosthetic knees may be 10 times more than the purely mechanical knees. While prosthetic knees have become more complex and expensive, it is not proven that the prosthetic knee is a central …

Design Of Recombinant Tenebrio Molitor Antifreeze Protein For Purification Using Elastin-Like Polypeptide Tag, Joongseok Oh

ETD Archive

Fusion protein technologies can aid to improve solubility of recombinant protein from microorganisms and help recombinant protein purification. Elastin-like polypeptides (ELP) as a fusion tag can be utilized to facilitate the purification of recombinant proteins because ELP can provide its thermally responsive behavior to ELP tagged proteins. An ELP tag can be used as the purification carrier through inverse transition cycling (ITC), which is a simple and non chromatographic separation process. The purification through ITC can reduce cost and can be quickly performed compared to other purification methods. However, we further considered ELP tag removal because it may possibly hinder …

Evolutionary Optimization Of Atrial Fibrillation Diagnostic Algorithms, Aref Smiley

ETD Archive

The goal of this research is to introduce an improved method for detecting atrial fibrillation (AF). The foundation of our algorithm is the irregularity of the RR intervals in the electrocardiogram (ECG) signal, and their correlation with AF. Three statistical techniques, including root mean squares of successive differences (RMSSD), turning points ratio (TPR), and Shannon entropy (SE), are used to detect RR interval irregularity. We use the Massachusetts Institution of Technology / Beth Israel Hospital (MIT-BIH) atrial fibrillation databases and their annotations to tune the parameters of the statistical methods by biogeography-based optimization (BBO), which is an evolutionary optimization algorithm. …

Evaluation And Characterization Of The Biomechanical Properties Of Tissue Engineered Vascular Grafts Implanted In The Arterial Circulation, Brooks Van Udelsman

Yale Medicine Thesis Digital Library

We used a murine model to assess the in vivo evolving biomechanical properties of tissue engineered vascular grafts (TEVGs) implanted in the arterial circulation. The initial polymeric tubular scaffold was fabricated from (poly)lactic acid (PLA) and coated with a 50:50 copolymer of (poly)caprolactone and (poly)lactic acid (P[PC/LA]). Following seeding with syngeneic bone marrow derived mononuclear cells, the TEVGs (n=50) were implanted as aortic interposition grafts in wild-type mice and monitored serially using ultrasound. A custom biaxial mechanical testing device was used to quantify in vitro the circumferential and axial mechanical properties of grafts explanted at 3 or 7 months. At …