Water Exchange Rate Across The Blood-Brain Barrier Is Associated With Csf Amyloid-Β 42 In Healthy Older Adults, Brian T. Gold, Xingfeng Shao, Tiffany L. Sudduth, Gregory A. Jicha, Donna M. Wilcock, Elayna R. Seago, Danny J. J. Wang

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: We tested if water exchange across the blood-brain barrier (BBB), estimated with a noninvasive magnetic resonance imaging (MRI) technique, is associated with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and neuropsychological function.

METHODS: Forty cognitively normal older adults (67–86 years old) were scanned with diffusion‐prepared, arterial spin labeling (DP‐ASL), which estimates water exchange rate across the BBB (k_w). Participants also underwent CSF draw and neuropsychological testing. Multiple linear regression models were run with kw as a predictor of CSF concentrations and neuropsychological scores.

RESULTS: In multiple brain regions, BBB kw was positively associated ...

Development Of An Intraperitoneal Catheter Placement Device For Use On The Battlefield, Riley Reynolds

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

The objective of this project was to simplify peritoneal cavity access so an Airforce field medic can safely infuse oxygen microbubbles (OMBs) into the intraperitoneal space for the emergency treatment of hypoxia due to lung damage. To solve this problem, we created an intraperitoneal catheter placement device for use on the battlefield. The three common methods and some of the most common devices for peritoneal cavity access were reviewed. Injury frequencies for each of the three methods were analyzed. The results showed that each of the access techniques gives a similar rate of iatrogenic injury.

The battlefield conditions where the ...

Biomethanation And Alkaline Wet Air Oxidation Of Water Hyacinth (Pontederia Crassipes) From Ozama River, Dominican Republic, Yessica A. Castro

All Graduate Theses and Dissertations

Obtaining valuable products from environmental remediation waste is a sustainable approach that contributes to the ecological well-being of developing countries. In the present work, the feasibility of the water hyacinth anaerobic digestion as a post-weed management practice in the Ozama River (Dominican Republic) was demonstrated. The estimated energy required for harvesting was lower than that produced during digestion. The biomethanation of water hyacinth was improved by Alkaline Wet Air Oxidation (AWAO), a thermochemical pretreatment process that almost doubled the methane production rate and increased the yield by 24% when conducted at high temperatures. At lower temperatures, the methane yield of ...

Involvement Of The Ino80 Chromatin Remodeling Complex In Cell Division And Genomic Stability, Ethan Chen

Biomedical Engineering Undergraduate Honors Theses

Cell division is a vital biological process for growth and development in both single and multi-cellular organisms—whereby the cell must duplicate its organelles and genome in entirety and appropriately distribute the copied contents to the daughter cells. Cells undergo a cycle of two distinct phases: interphase and mitosis. During interphase, the cell replicates its genomic DNA (in the form of chromosomes) located within the nucleus. DNA replication is carried out in a euchromatin state, where the chromosome structure is loose and easily accessible by DNA polymerase and other replication enzymes. Upon the completion of replication, chromatin is condensed into ...

Guide Rnas Preparation For In-Vitro Crispr-Cas9 Complex Delivery Targeting Genes That Affect Wound Healing., Prashant Khatiwada

Biomedical Engineering Undergraduate Honors Theses

CRISPR-Cas9 technology has widely been used as a viable genome engineering platform to make site-specific insertion, deletion, and breaks. The nuclease dead version of Cas9 or dCas9 can be used for the activation and repression of target gene sites using specific activation or repression domains. In this study, CRISPR guide RNAs were designed for a CRISPR inhibition approach to repress the transcriptional activity of the target genes. An expression plasmid vector composed of a U6 promoter sequence, BbsI restriction sites, and a chimeric gRNA sequence was digested, and the phosphorylated forward and reverse gRNAs were ligated with the plasmid vector ...

Development Of An Integrated Salt Cartridge-Reverse Electrodialysis (Red) Device To Increase Electrolyte Concentrations Of Human Blood Flow To Power Biomedical Devices, Caroline Campbell

Chemical Engineering Undergraduate Honors Theses

Emerging technologies in nanotechnology and biomedical sciences have led to an increase in biomedical implantable devices including cardiac pacemakers, artificial organs, drug pumps, and sensors. These devices require continuous stable and reliable power to operate, which creates the demand for the need to find a safe, reliable, and stable power source. A promising avenue for a power source for these devices is a miniaturized reverse electrodialysis (RED) biopower cell design that utilizes the salinity differences between bloodstreams that flow inside the human body. Initial results of the RED system demonstrate that higher gradient salinity differences between streams lead to a ...

Design Of Control Logic And The Human-Machine Interface For A Demonstration Plant Growth Chamber Implemented On A Programmable Logic Controller, Rachael Koehler

Biological and Agricultural Engineering Undergraduate Honors Theses

This honors thesis covers the planning, development, and implementation of system controls and human-machine interface (HMI) for a demonstration plant growth chamber. The work is a continuation of an ongoing project to be used as an educational and recruiting tool manifesting the skills acquired from the Biological and Agricultural Engineering Department at the University of Arkansas’ College of Engineering. This work includes emergency controls, overall design interface, and controls for both the aeration and lighting subsystems of the growth chamber. Overall design interface controls established included development of two user modes, Administrator and Visitor. The Administrator user will have full ...

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive ...

Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell

Biological and Agricultural Engineering Undergraduate Honors Theses

Photovoltaic solar panels convert sunlight to electricity in the form of direct current; therefore, a necessary component of every photovoltaic system is an inverter to convert the electricity to usable alternating current. There are various commercially available inverter technologies manufactured today such as microinverters, string inverters, and central inverters, as well as module level power electronic devices such as DC optimizers that are capable of improving system performance in string and central inverter systems. This thesis compares the performance and economics of five different inverter and module level power electronic systems through model simulation using Helioscope software. The five alternatives ...

Immunomodulatory Biomaterials For Cancer Immunotherapy, Larry Donnell Stokes Jr

Honors Theses

Cancer immunotherapy has become an effective treatment in the toolbox of oncologists. Immunotherapy offers a less toxic alternative to standard cancer treatments such as chemotherapy and can have prolonged curative effects to decrease cancer recurrence. Today, many drugs and biological agents have been developed that target the immune system and elicit an antitumor/cancer response. These agents are known collectively as cancer immunotherapies. While immunotherapies have radically improved treatment outcomes for many cancer patients, there are drawbacks to using these treatments. Immunotherapy treatments have poor clinical responses in patients with tumors that lack immunogenicity. Some of the treatments also pose ...

Analyzing The Effects Of E-Hook Peptides On Kinesin-1, Ashton Ward Murrah, Baylee Hope Howard

Honors Theses

Cancer is the second leading cause of death in the United States. Cancerous growth is a result of oncogenes, or mutated genes that increase the rate of cell division in an uncontrolled manner. Cell division, which consists of mitosis and cytokinesis phases, is dependent upon the active movement of kinesin motor proteins along microtubules to rearrange the cytoskeleton for equitable distribution of genetic material to daughter cells. As kinesins are vital to this process, if we could prevent kinesin from binding to the microtubules, cell division would cease.

The goal of this study is to develop a method to prevent ...

Molecular Mechanisms Of Oxidative Stress On Molecular Motors, Addison Caspari-Linhardt

Honors Theses

Astronauts encounter many forms of ionizing radiation during space travel. Ionizing radiation has been seen to cause cancer, cataracts, radiation sickness, tissue damage, hereditary effects, and damage to the central nervous system. Ionizing radiation can damage DNA molecules through oxidation, as well as other vital proteins like molecular motors. Kinesin-1 is a molecular motor protein that essential to intracellular transport. Microtubules serve as the “roadway” for kinesin transport, where kinesin converts chemical energy from ATP hydrolysis into mechanochemical “steps” to move along the microtubules. Optical trapping has been used in previous research to measure single kinesin motor properties. We have ...

Design Of An Undergraduate Laboratory Experiment Utilizing A Stirred-Tank, Jacketed Bioreactor, Brennen Middleton

Honors Theses

Bioreactors are utilized in many industries, such as the food, alternative fuel, and pharmaceutical industries, to design and manufacture products. Unlike the similar chemical batch reactors utilized in many chemical processing facilities, bioreactor utilization requires engineers to consider a wider range of operating conditions and parameters. This results in a more complex reaction system and controls network. Due to this, it is imperative for chemical and biomedical engineering students to not only understand the theory surrounding these reactor systems, but also understand how to properly design and perform operating procedures with these systems. Thus, it was determined to create an ...

Nitinol Robotic Arm, Brandon Cousino, Connor Sweatt

Thinking Matters Symposium

The goal of our project is to create a remotely controlled robotic arm using a nickel-titanium alloy (Nitinol) that exhibits “shape memory” tendencies and a 9-lumen tube. The arm must be able to move in all for directions (forward, left, right, backwards) with the control of a joystick and return to an upright position upon halting user input (thus requiring a two-way shape memory ability). The final product must operate without any unwanted twisting of the arm, crosstalk between the different nitinol wires due to heating, and be easily manufacturable. Easy replacement of the arm from the main mechanism is ...

Mems Directional Acoustic Sensors, Colby Damren

Thinking Matters Symposium

The purpose of my project is to test and verify two Micro-Electro-Mechanical-System (MEMS) microphones. The two MEMS devices are biomimetic microphones that imitate the eardrums of the Ormia Ochracea, a parasitic fly that listens for host crickets to lay their eggs. The MEMS microphones mimic the eardrum spacing of the Ormia Ochracea with a spacing of 1000um. This is roughly twice the opening of the Ormia Ochracea. The microphones will be tested for directionality inside a wooden box. This box will be lined with beveled foam to prevent any echo or outside noise from interfering with the results. These results ...

Design, Simulation And Testing Of Biomimetic Directional Acoustic Sensors, Brendan Francis

Thinking Matters Symposium

The Ormia ochracea, a species of parasitic fly, has become the focal point in sound localization research because of its finely tuned hearing abilities. The female of this species uses its super highly directional hearing to pinpoint the call of a host cricket, with hypersensitivity of frequency and phase difference, to reach and dispose of its eggs on the host. The goal of this study was to further the research of a previous Project in Professor Guvench’s group which implemented MEMS (Micro Electro-Mechanical System) technology on a chip to replicate these abilities. In this iteration, however, some commercially available ...

Biomedical Applications And Syntheses Of Selected Anthraquinone Dyes, Richard Sirard

Senior Honors Theses

Anthraquinones are aromatic organic compounds that have multiple applications in the biomedical field. Some anthraquinone-based compounds are used as fluorophores to contrast cell nuclei while others act as chemotherapeutic agents. However, there are not many fluorescent anthraquinone cell stains currently available. In this study, commercially available anthraquinone dyes, in addition to other dye families and compounds, were reviewed for their unique properties, advantages, and drawbacks. The development and characterization of three novel anthraquinone fluorophores revealed promising photophysical characteristics, like large Stokes shifts. One of the compounds, RBS3, was chosen for fixed and live cell staining and exhibited desirable biomedical properties ...

A Brief Bibliometric Survey Of Explainable Ai In Medical Field, Nilkanth Mukund Deshpande, Shilpa Shailesh Gite

Library Philosophy and Practice (e-journal)

_{^{Background: This study aims to analyze the work done in the field of explainability related to artificial intelligence, especially in the medical field from 2004 onwards using the bibliometric methods.}}

_{^{Methods: different articles based on the topic leukemia detection were retrieved using one of the most popular database- Scopus. The articles are considered from 2004 onwards. Scopus analyzer is used for different types of analysis including documents by year, source, county and so on. There are other different analysis tools such as VOSviewer Version 1.6.15. This is used for the analysis of different units such as co-authorship, co-occurrences ...}}

Catechol-Containing Copolymers As An Active Ingredient For Denture Adhesives, Vincent Ying Wun Kong

Electronic Thesis and Dissertation Repository

Moisture inside the mouth adds challenge to making denture adhesives formulations. Some formulations have zinc to enhance adhesion on wet skin despite knowing the health hazards. Inspired by mussel foot proteins’ catechol unit’s strong underwater adhesion, nine catechol-containing copolymers (P1A-P3C) were synthesized by free radical polymerization of 3,4-dimethoxystyrene (3,4- DMS) with different styrene derivatives followed by deprotection. P1A-P3C were used to make Fn(P)-C-PBS denture adhesive formulations which had suitable shear stresses around ≥ 5 kPa satisfying ISO 10873. In-situ NMR studies of free radical polymerization of 3,4 - DMS and styrene derivatives allowed computation of their ...

Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber

Biological Systems Engineering--Dissertations, Theses, and Student Research

High resolution, long-term monitoring of key biological analytes would improve patient outcomes by providing earlier detection of disease states and improved efficacy of treatment. One class of biosensors that have gained much attention in recent years are optical biosensors. Optical probes are attractive biosensors due to their noninvasive nature of detection, as certain light can pass through tissue, water, and blood. Single walled carbon nanotubes (SWNT) are a specific type of optical biosensor that fluoresce in the near infrared range of the electromagnetic spectrum and offer unparalleled spatial and temporal resolution. SWNT have been applied as biosensors in vitro, ex ...