Biomedical Engineering and Bioengineering Commons^™

Directional Solidification Of Al - 7 Wt Si Alloy, Ravi Shanker Rajamure

ETD Archive

Al - 7 wt Si alloy has been directionally solidified from an aluminum single crystal seed with its [100] orientation parallel to the growth direction with a positive thermal gradient of 40 K/cm and over the range of growth speeds. Growth speed dependence of primary Dendrite Spacing and Primary Dendrite trunk Diameter has been analyzed during the step increase and step decrease in the growth speeds. Frequency distribution of Nearest Neighbor dendrites obtained from the statistical analysis shows the hexagonal distribution of dendrites. The interdendritic convection was present in the form of transverse macrosegregation and non uniform distribution of dendrites …

A Theoretical Model Of The Effect Of Bone Defects On Anterior Shoulder Instability: A Finite Element Approach, Piyush Walia

ETD Archive

Presence of either a Hill Sachs or a Bony Bankart lesion has been indicated as a possible cause of subluxation and anterior shoulder dislocation. Previous studies have investigated only effects of these isolated lesions on the glenohumeral instability of the shoulder. The purpose of this thesis was to investigate the effect of both Bony Bankart lesion and Hill-Sachs lesion in the glenohumeral joint on the stability of the shoulder. We hypothesize that as the size of the lesion increases, the glenohumeral joint's stability will decrease. We further hypothesize that the presence of both defects together will reduce the glenohumeral joint's …

Application Of Differential Scanning Calorimetry To Characterize Thin Film Deposition Processes, Andrew John Roger Snell

ETD Archive

With the recent increase in awareness on the environmental impact of industrial coating processes, chromate-based coating processes have been elevated to the rank of the technologies targeted by the EPA for rapid replacement by environmentally friendly processes. Therefore, there is a clear need for advances in coating technologies to identify alternative industrial practices. This thesis characterizes a process developed at Cleveland State University as an alternative deposition technique to generate uniform coatings onto solid substrates. A kinetic analysis to extract scale up parameters involved in the reaction kinetics leading to high-performance coatings is demonstrated in this research. The work consists …

Raman Spectroscopic Modeling Of T- Lymphocyte Activation And Detection Of Acute Renal Allograft Rejection, Kristian L. Brown

Wayne State University Dissertations

ABSTRACT

RAMAN SPECTROSCOPIC MODELING OF T-LYMPHOCYTE ACTIVATION AND DETECTION OF ACUTE RENAL ALLOGRAFT REJECTION

By

KRISTIAN L. BROWN

2010

Advisor: Gregory Auner, PhD

Major: Biomedical Engineering

Degree: Doctor of Philosophy

Despite the advances made in the area of kidney transplantation, the disparity between the demand and available donated organs remains a dominant and unresolved issue. Given the paucity of available renal allografts the preservation of existing grafts is vital. One factor that has negatively impacted renal allograft survival is acute rejection (AR). Traditionally, kidney transplant centers have used elevations in serum creatinine as a screening tool for detecting AR. However, …

Identification Of Neuroblastoma And Its Prognostic Markers Using Raman Spectroscopy, Rachel Kast

Wayne State University Dissertations

Introduction: Neuroblastoma is the most common cancer of infancy. It is one of several peripheral nervous system tumors, including ganglioneuroma, peripheral nerve sheath tumor, and pheochromocytoma. It is commonly situated on the adrenal gland. It displays similar histology to other small round blue cell tumors, including non-Hodgkin lymphoma, rhabdomyosarcoma, and Ewing sarcoma. One method of judging neuroblastoma aggressiveness uses tumor histology factors, including mitosis-karyorrhexis index, Schwannian stromal development, degree of differentiation, and patient age. Tumor aggressiveness can also be judged based on the amplification of certain genes, including MYCN. Raman spectroscopy is a physics-based method which identifies the biochemical …

Understanding The Molecular Dynamics Of Ypel3 And Fhit Gene Expression, Kevin Daniel Kelley

Browse all Theses and Dissertations

A comprehensive understanding of the molecular signaling pathways that regulate cell growth and proliferation is essential in the realization of new therapeutic options to facilitate early detection and eradication of malignancy. Understanding the transcriptional regulation of the YPEL3 and FHIT genes forms the basis of this dissertation. YPEL3, or Yippee-like 3, is a newly identified p53 target gene that inhibits tumor cell growth and is thus itself, a novel tumor suppressor gene. FHIT, or Fragile histidine triad, is a well known tumor suppressor gene and is regulated at the transcriptional level by another growth inhibitory protein, FOXO3a, a Forkhead box …

Magnetic Resonance Spectroscopy Study Of Metabolic Profiles In Brain Tumors, Aditya Manoj Patel

Bioengineering Theses - Archive

Metabolic profiles in brain tumors were measured using proton (1H) magnetic resonance spectroscopy (MRS) at 3T. Spectra were obtained from normal tissues and tumor mass regions of 6 low-grade gliomas, 7 anaplastic astrocytomas and 23 glioblastoma (GBM) patients, using PRESS at two echo times (TE = 54 and 112 ms). Glutamate (Glu), glutamine (Gln) and lactate (Lac) were well resolved at TE = 112 ms. The ratio of Gln and Glu concentrations, [Gln]/[Glu], was elevated significantly (p < 0.05) in all the tumor types compared to normal tissue. Elevation of Gln was confirmed through [Gln]/[water]; the ratio was increased in all the three tumor types but the increase was significant only in GBM. Glycine (Gly) was increased significantly in GBM. Alanine was detectable from GBM only, indicating its elevation for most malignant tumor. Other observations included significant increases in choline (Cho) and Lac (p < 0.05) and decrease in NAA (N-acetylaspartate), in consistent with prior studies. The creatine to water ratio was observed to decrease in tumor patients but was not significant. Myo-inositol (mIns) was observed to decrease in low grade patients as compared to normal tissue, but was seen to increase with grade of tumor, but was not significant. [Lac]/[water] was significantly higher and [Cho]/[Lac] significantly lower for GBM patients indicating the increase in Lac as compared to normal tissue.Treatment had a significant impact on tumor cells. After radiation therapy the Lac was observed to be elevated significantly and decrease after bevacizumab treatment. [Cho]/[Cr], [Cho]/[NAA], [Gln]/[Glu] and [Cho]/[Gly] was reduced significantly after the bevacizumab treatment. Gly was not detectable after Bevacizumab treatment. Some of the patients showed no infiltrating tumor cells after successful surgery and therapy with ratios close to that of normal tissue. These observations can help in characterizing the effect of various therapies on brain metabolites and tumor cells.

Targeted Delivery Of Carbon Nanotubes To Cancer Cells, Pavitra Chakravarty

Bioengineering Dissertations - Archive

CD22 is broadly expressed on human B cell lymphomas. Monoclonal anti-CD22 antibodies (MAbs) alone, or coupled to toxins, have been used to selectively target these tumors both in severe combined immunodeficient (SCID) mice with xenografted human lymphomas and in patients. Single-walled carbon nanotubes (CNTs) attached to antibodies or peptides represent another approach to targeting cancer cells. CNTs convert absorbed near-infrared (NIR) light into heat, which can thermally ablate cells in the vicinity of the CNTs. We have made MAb-CNT constructs where the MAb was either noncovalently or covalently coupled to CNTs, and investigated their ability to bind specifically to cells …

Post-Operative Renal Function Analysis Using Visible Dlp® Hyperspectral Imaging System, Abhas Thapa

Bioengineering Theses - Archive

Surgical and clinical settings in medical hospitals strive to keep up with technological innovations in order to improve the current healthcare scenario. Hyperspectral imaging (HSI) is a novel technology that addresses this problem. HSI is a non-invasive imaging technique that can provide information on both structural and functional conditions of tissue. This information is very useful particularly in live surgical procedures wherein the surgeons can get real-time feedback of the anatomical and functional changes of tissue, as they perform the operation. Currently available HSI systems are extremely slow and thus impractical for time restricted surgical or clinical uses. Hence, DLP® …

Enhanced Endothelialization On Surface Modified Poly(L-Lactic Acid), Hao Xu

Bioengineering Dissertations - Archive

Current synthetic vascular grafts and polymer-coated drug-eluting stents (DES) have certain limitations, such as thrombosis and restenosis due to the incomplete recovery of vascular endothelial cells on their luminal sides. Surface modification of these materials is a viable method to enhance the endothelialization on them. In this study, we proposed several way to modify poly(L-lactic acid) (PLLA), a promising material for vascular prostheses to enhance the endothelialization on its surface. In the first method, we modified the material surface with deposition of poly(vinylacetic acid) (PVAA) using plasma polymerization. PVAA having different surface densities of -COOH group or film thickness were …

Wide Field Of View Imaging Of Premotor And Sensorimotor Cortex Activation Patterns By Functional Near Infrared Spectroscopy, Pankaj Chand

Bioengineering Theses - Archive

Functional near infrared spectroscopy (fNIRS) is a non-invasive optical technique which can measure concentration changes of oxygenated (HbO), deoxygenated (HbR), and total hemoglobin (HbT) in brain tissue that are induced by neuronal activation. A major hindrance at present for brain optical imaging research is the limited field of view (FOV) size, which is restricted due to the limited number of source-detector pairs that current fNIRS hardware technology and cost considerations allow. As a result it is challenging to simultaneously capture hemodynamic changes in the premotor, motor and sensory cortex as some of these activations can occur outside the available FOV. …

Novel Animal Model And In Vivo Imaging System To Study Inflammatory Response-Mediated Cancer Metastasis, Cheng-Yu Ko

Bioengineering Dissertations - Archive

Cancer metastasis is the leading cause of death in cancer patients. A vast majority of cancer-related mortality is attributed to this rather than the primary tumor itself, making the understanding of cancer metastasis critically important. Inflammatory responses have been implicated to play an important role in cancer metastasis. However, the investigation of the relationship between inflammation and cancer cell migration is limited by the lack of a reproducible cancer metastasis animal model. To fill the gap, we have recently developed an animal model. This model is composed of a two-step procedure. First, poly-L lactic acid (PLA) microspheres were implanted subcutaneously …

Mechanisms Of Biomaterial Mediated Fibrotic Responses And Strategies To Improve Tissue Reactions To Biomaterial Implants, Paul Todd Thevenot

Bioengineering Dissertations - Archive

Despite considerable advancements in biomaterial synthesis and modification techniques, most tissue engineering scaffolds elicit fibrotic reactions resulting in implant encapsulation, secluding cells and/or therapeutic agents within a thick collagenous matrix. Therefore, strategies to minimize these responses while improving the functionality of recruited/transplanted cells are required. This work set out to improve the host response to biomaterials and identify what cellular responses were attributed to biomaterial-mediated fibrosis. Two strategies were investigated involving two different targets. In the first approach, PLGA scaffolds were RFGD modified to bear -NH2 (amine), -COOH (carboxyl), and -OH (hydroxyl) groups altering surface wettability and charge properties. Surface …

Investigation Of End-Tidal Carbon Dioxide (Etco₂) And Heart Rate Variations During Sleep Apnea, Aditya Bashaboyina

Bioengineering Theses - Archive

Sleep Apnea is a sleep disorder where limitation or cessation of breathing occurs. It is characterized by abnormalities in the respiratory pattern and quantity of ventilation during sleep. According to a study 4% of men and 2% of women have sleep apnea, which is a sizable sector of the adult population. To analyze end-tidal CO₂ and heart hate variations due to apnea, 8 hr polysomnography (Sleep Consultant. Inc, Fort Worth, Texas) was performed on limited sleep apnea subjects and breath hold maneuvers were performed in awake subjects. In the simulated apnea study, 16 volunteer subjects (age: 29 ± 5 yrs, …

Multi-Ligand Nanoparticles For Targeted Drug Delivery To The Injured Vascular Wall, Soujanya Kona

Bioengineering Dissertations - Archive

Pathological conditions like coronary artery disease, acute myocardial infarction, stroke, and peripheral artery diseases as well as cardiovascular interventions used in the treatment of coronary artery diseases such as angioplasty and stenting, damage/injure the blood vessel wall, leading to inflamed or activated endothelial cells that have been implicated in events leading to thrombosis, inflammation, and restenosis. Oral administration of anti-coagulant and anti-inflammatory drugs causes systemic toxicity, bleeding, patient incompliance, and inadequate amounts of drugs at the injured area. Though drug-eluting stents have shown therapeutic benefits, complications such as in-stent restenosis and late thrombosis still remain and are a cause for …

Development Of Orchestrated Stem Cell-Based Regeneration (Oscer) -Strategies To Recruit And Differentiate Autologous Stem Cells For Tissue Regeneration, Ashwin Nair

Bioengineering Dissertations - Archive

Stem cell therapy has shown great promise in curing diseases. However, clinical application of stem cell therapy is often hindered by the lack of reliable sources and convenient methods to recover stem cells. Our laboratory has recently discovered that adult stem cells can be actively recruited via inflammatory chemokines/growth factor. My research was aimed towards the development of a new technology - "Orchestrated Stem Cell-based Regeneration" or OSCeR - to induce stem cell-mediated tissue regeneration by blending stem cell therapy and tissue engineering technology. This work has led to a series of interesting findings as listed below. Shortly after implantation, …

Quantitative Variation Of Blood Pressure Dynamics During Sleep Apnea, Raichel Mary Alex

Bioengineering Theses - Archive

Sleep Apnea is one of the major sleep disorders characterized by complete cessation or decline in breathing for about 10s or more during sleep, thereby adversely affecting the quality of sleep. Studies show that about 6 % of the US adult population suffers from obstructive sleep apnea, which in turn plays a major role in the development of hypertension, heart failure, stroke and is also responsible for reduced performance in everyday activities due to lack of quality sleep. In this study the physiological response to sleep apnea were determined using beat to beat blood pressure in both healthy subjects and …

Innovations In ¹H Mr Tissue Oximetry: New Probes And Pulses, Ujjawal Rastogi

Bioengineering Theses - Archive

Low oxygenation level (hypoxia) of tissue leads to cellular dysfunction, damage and poor response to therapy. Quantitative measurement of tissue oxygenation is critical not only for the study of tissue physiology, but could also help improve efficacy of therapeutic procedures. Our group has previously developed and implemented a novel approach to quantify oxygen tension in tissue using ¹H MRI, known as “PISTOL” (Proton Imaging of Siloxanes to map Tissue Oxygenation Levels). It exploits a linear relationship between the longitudinal relaxation rate (R1) and oxygen tension (pO₂) of a reporter molecule (probe). Due to close proximity of fat (~ 1 ppm) …

A Study Of The Physiological Effects Of Sleep Apnea On Cerebral Blood Flow Velocity, Gauri Bhave

Bioengineering Theses - Archive

It is estimated that sleep apnea is prevalent in the US in about 18 million people. The prevalence rate is approximately 6% in the US. Sleep apnea reduces the quality of life of patients. Sleep apnea is characterized by repetitive pauses in breathing during sleep. Recent studies also show loss of gray matter in people diagnosed with sleep apnea. To study the physiological effects of sleep apnea on cerebral blood flow velocity (CBFV), CBFV was measured in subjects simulating apnea. Sixteen volunteers (29 ± 5 yr and BMI 24.1±4.8, 9M and 7F) were recruited as control subjects. We measured CBFV …

An Investigation Of Peripheral Blood Volume And Oxygen Saturation Change In Obstructive Sleep Apnea, Swathi Iyer

Bioengineering Theses - Archive

Obstructive sleep apnea (OSA) is a type of sleep disordered breathing in which the airway collapse partially or fully and causes arousal to resume breathing. In a 2009 National sleep foundation poll of 1000 people, 63% of men and 50% of the females showed signs of sleep apnea. It also showed that subjects with sleep apnea have high risk of high blood pressure, stroke and mental disorders such as depression especially in female. Also by another group of researcher it has been shown that the prevalence of OSA is 4% in male and 2% in female. It has been also …

In Vivo Tracking Of Mesenchymal Stem Cell Recruitment To Tissue Scaffolds, Manwu Sun

Bioengineering Theses - Archive

The term "Stem cells" has been extensively used to describe precursor undifferentiated cells that have the capacity to self-renew and can also give rise to multiple tissue types. Many studies have been shown improved functional outcome after treated with stem cell therapy. However, almost all of these investigations were analyzed based on histological evaluations which are time-consuming, expensive and fail to provide 3 dimensional and real-time information about stem cell responses. Therefore, there is a need for the development of new method to investigate the migration of stem cells in vivo. Recent evidence supports that fluorescence imaging system offer both …

Attenuation Based Quantification Of Interstitial Lung Disease Using High Resolution Computed Tomography And Correlation With Pulmonary Function Tests, Snehal S. Watharkar

Bioengineering Theses - Archive

Interstitial lung disease (ILD) is a chronic and progressive pulmonary disease of the lung parenchyma resulting in fibrotic scar formation of the pulmonary alveoli. The pathologic changes in the lung result in restrictive impairment of lung function. High resolution computed tomography (HRCT) of the chest has become an essential technique in diagnosing and assessing the extent of ILD. Clinical evaluation by HRCT is usually qualitative, leading to inter-observer variability particularly in detecting early disease. We propose a quantitative attenuation-based analysis to standardize the assessment of regional lung disease. We hypothesize that early ILD is associated with greater regional heterogeneity than …

Transgenic Rat Model Of Neurodegeneration Caused By Mutation In The Tdp Gene, Hongxia Zhou, Cao Huang, Han Chen, Dian Wang, Carlisle P. Landel, Pedro Yuxing Xia, Robert Bowser, Yong-Jian Liu, Xu Gang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons …

Effect Of Magnetron Frequency On Heating Pattern In Domestic Oven, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

In this study a computer model was developed to simulate microwave heating of a model food with a range of magnetron frequencies. The range was decided upon performing the frequency spectrum analysis of microwave leakage from the microwave oven. Simulation results showed that the magnetron input as sinusoidal frequency from 2.44 GHz to 2.48 GHz generates different heating profiles. The simulated heating profiles were compared with experimental heating profiles obtained by using an IR camera. None of simulations with individual frequency exactly matches with experimental temperature profile. The closet match between simulated and observed temperature profiles was found with 2.46 …

Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Coastal Bermuda grass was pretreated with NaOH at concentrations from 0.5% to 3% (w/v) for a residence time from 15 to 90 minutes at 121 °C. The pretreatments were evaluated based on total lignin removal and production of total reducing sugars, glucose and xylose from enzymatic hydrolysis of the pretreated biomass. Up to 86% lignin removal was observed. The optimal NaOH pretreatment conditions at 121 °C for total reducing sugars production as well as glucose and xylose yields are 15 minutes and 0.75% NaOH. Under these optimal pretreatment conditions, total reducing sugars yield was about 71% of the theoretical maximum, …

Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study used two different approaches to model changes in biomass composition during microwave-based pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the pretreatment. Training and testing data sets for development and validation of the models were obtained from pretreatment experiments conducted using 1–3% w/v NaOH (sodium hydroxide) and pretreatment times ranging from 5 to 20 minutes. The kinetic modeling approach for lignin …

Dual-Stage Sugar Substitution In Strawberries With A Stevia-Based Sweetener, Juan Garcia-Noguera, Curtis L. Weller, Francisca I. P. Oliveira, Sueli Rodrigues, Fabiano A. N. Fernandes

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The present study introduces and analyzes a new process denominated dual-stage sugar substitution (D3S). This process aims to induce sugar substitution in strawberries. In a first stage, high-calorie sugars (sucrose, fructose and glucose) are partially removed from the fruit samples and in a second stage, low-calorie sugar (stevioside and rebaudioside) is incorporated to the fruit to maintain its sweetness. The process was evaluated by studying the use of ultrasound application in one or both stages of the D3S process. Best performance of the process was obtained by subjecting the fruit samples to ultrasound in the sugar removal stage followed by …

Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This paper reports a new method of cross-linking electrospun zein fibers using citric acid as a non-toxic cross-linker to enhance the water stability and cytocompatibility of zein fibers for tissue engineering and other medical applications. The electrospun structure has many advantages over other types of structures and protein-based biomaterials possess unique properties preferred for tissue engineering and other medical applications. However, ultrafine fiber matrices developed from proteins have poor mechanical properties and morphological stability in the aqueous environments required for medical applications. Efforts have been made to improve the water stability of electrospun protein scaffolds using cross-linking and other approaches, …

Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave-based alkali pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 minutes. Simons’ stain method was used to quantify changes in biomass porosity as a result of the pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and xylose. …

Retrofit Of Distillation Columns In Biodiesel Production Plants, Nghi Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Column grand composite curves and the exergy loss profiles produced by the Column-Targeting Tool of the Aspen Plus simulator are used to assess the performance of the existing distillation columns, and reduce the costs of operation by appropriate retrofits in a biodiesel production plant. Effectiveness of the retrofits is assessed by means of thermodynamics and economic improvements. We have considered a biodiesel plant utilizing three distillation columns to purify biodiesel (fatty acid methyl ester) and byproduct glycerol as well as reduce the waste. The assessments of the base case simulation have indicated the need for modifications for the distillation columns. …