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Full-Text Articles in Engineering

Sodium Hyaluronate Based Drug Delivery To The Outer And Inner Ear, Emma Barrett-Catton Jan 2023

Sodium Hyaluronate Based Drug Delivery To The Outer And Inner Ear, Emma Barrett-Catton

Graduate Student Theses, Dissertations, & Professional Papers

We have developed two projects using sodium hyaluronate (HA)-based systems for drug delivery to the ear. First, we investigated an HA-based hydrogel for use as a single use antibiotic treatment for otitis externa. Otitis externa, also known as outer ear infection, is a frequent affliction in both humans and animals. The most prevalent treatment for otitis externa is ear drops, but it is difficult to adhere properly to this treatment, causing poor patient compliance and the potential for complications. As a result, we have developed an HA-based hydrogel for use as a single application treatment for otitis externa to increase …


Evaluation Of Changes In Cellular Behavior Upon Exposure To Selected Analytes Used In Synthetic Applications, Olivia L. Rose Jan 2023

Evaluation Of Changes In Cellular Behavior Upon Exposure To Selected Analytes Used In Synthetic Applications, Olivia L. Rose

Graduate Theses, Dissertations, and Problem Reports (ETD)

Metal-organic frameworks (MOFs) are organic crystalline hybrids that have been used for a variety of applications from catalysis to gas storage and drug delivery. Studies have shown that generally, while such frameworks are more biocompatible than similar aspect ratio nanostructures, they are also more prone to transformation and disintegration due to their flexible and fragile nature as resulted from the structure assembly and implemented structure-function relationships. With extensive previous literature showing that materials with nano dimensions such as carbon nanotubes, quantum dots and other nanomaterials have unique physicochemical properties that lead to increased biosystems’ reactivity. With increasing concerns regarding adverse …


Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell Jan 2023

Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electron paramagnetic resonance (EPR), and its molecular imaging modality, is a powerful tool to noninvasively map various biological and chemical markers within objects of interest. Reliable data acquisition is a major impeding factor for longitudinal hands-off measurements. Measurements are especially challenging in biomedical applications, as live objects are not static. Frequent changes occur that require constant fine recalibration of the EPR detection system, called the resonator. To enable longitudinal imaging, a technology permitting automatic digital control of resonator coupling, tuning, and EPR data acquisition was developed. Automation was achieved through the utilization of a microcontroller and digital peripheral components such …


Advancing Medical Technology For Motor Impairment Rehabilitation: Tools, Protocols, And Devices, Matthew Yough Jan 2023

Advancing Medical Technology For Motor Impairment Rehabilitation: Tools, Protocols, And Devices, Matthew Yough

Graduate Theses, Dissertations, and Problem Reports (ETD)

Excellent motor control skills are necessary to live a high-quality life. Activities such as walking, getting dressed, and feeding yourself may seem mundane, but injuries to the neuromuscular system can render these tasks difficult or even impossible to accomplish without assistance. Statistics indicate that well over 100 million people are affected by diseases or injuries, such as stroke, Parkinson’s Disease, Multiple Sclerosis, Cerebral Palsy, peripheral nerve injury, spinal cord injury, and amputation, that negatively impact their motor abilities. This wide array of injuries presents a challenge to the medical field as optimal treatment paradigms are often difficult to implement due …


Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi Jan 2023

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …


Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu Jan 2023

Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu

College of Graduate Studies: Theses & Dissertations

This project focuses on the design and fabrication of an experimental setup for orthopedic-tool testing, tailored for a surgical instrumentation company. The multifaceted project encompasses a literature review, conceptual design, prototyping, and rigorous testing, resulting in a versatile control system capable of assessing various orthopedic tools, including bone drills, saws, burrs, and power handpieces.

Orthopedic surgical procedures (which include cutting and/or drilling into bone) often need to be performed on bones for faster recovery. The drilling and cutting process can cause an increase in temperature at the cutting site which can cause bone necrosis. The tools also need to be …


Development Of A Solution Synthesis Of Poly(Sebacic Anhydride) With The Activating Agent 4-Toluenesulfonyl Chloride: Understanding The Effect Of Different Bases On The Reaction Products, Patricia Poley Jan 2023

Development Of A Solution Synthesis Of Poly(Sebacic Anhydride) With The Activating Agent 4-Toluenesulfonyl Chloride: Understanding The Effect Of Different Bases On The Reaction Products, Patricia Poley

Honors Theses

The overall goal of this honors thesis was to develop a solution synthesis of Poly(Sebacic Anhydride) with the activating agent 4-toluenesulfonyl chloride and understand the effects of varying temperature, bases, and the addition order of reagents on the reaction.

Polyanhydrides are a class of hydrophobic, degradable polymers used in controlled drug delivery for 30 years. They are synthesized through three general methods: melt polycondensation, solution polycondensation, and ring-opening polymerization. Of these three methods, solution polycondensation typically results in products with lower molecular weight. Previous work in the Vogel lab identified two new ways to synthesize anhydrides using solution polycondensation reactions …


The Effects Of Dental Hygiene Instrument Handles On Muscle Activity Production, Jessica R. Suedbeck, Daniel Russell, Cortney Armitano Lago, Emily A. Ludwig Jan 2023

The Effects Of Dental Hygiene Instrument Handles On Muscle Activity Production, Jessica R. Suedbeck, Daniel Russell, Cortney Armitano Lago, Emily A. Ludwig

Dental Hygiene Faculty Publications

Purpose The objective of this study was to compare the effects of ten commercially available instrument handle designs’ mass and diameter on forearm muscle activity during a simulated periodontal scaling experience.

Methods A convenience sample of 25 registered dental hygienists were recruited for this IRB-approved study. Ten commercially available instruments were categorized into four groups based on their masses and diameters: large diameter/light mass, small diameter/light mass, large diameter/heavy mass, and small diameter/heavy mass. Participants were randomized to four instruments with one from each group. Participants scaled with each instrument in a simulated oral environment while muscle activity was collected …


Exploring Ph Gradient Phenomena In Non-Linear Electrokinetic Microfluidic Devices, Azade Tahmasebi Jan 2023

Exploring Ph Gradient Phenomena In Non-Linear Electrokinetic Microfluidic Devices, Azade Tahmasebi

Dissertations, Master's Theses and Master's Reports

Electrokinetic microfluidics is a versatile technology utilized within lab on a chip (LOC) devices for diagnostic and analytical applications; advantages include reduced resource demands, flexibility, and simplicity of use. Dielectrophoresis (DEP) is a precision nonlinear electrokinetic tool utilized within microfluidic microdevices to induce polarization and control bioparticle motions for applications that range from hemoglobin separations to cancer cell isolation and detection. Despite promising results, undesired side phenomena can occur in electrokinetic systems which impede reproducibility and accuracy. These unfavorable phenomena have not been comprehensively explored in the literature. Prior preliminary research suggests the fundamental phenomena originate from microelectrodes utilized in …


An Acute Respiratory Distress Syndrome Drug Development Collaboration Stimulated By The Virginia Drug Discovery Consortium, John S. Lazo, Ruben M.L. Colunga-Biancatelli, Pavel A. Solopov, John D. Catravas Jan 2023

An Acute Respiratory Distress Syndrome Drug Development Collaboration Stimulated By The Virginia Drug Discovery Consortium, John S. Lazo, Ruben M.L. Colunga-Biancatelli, Pavel A. Solopov, John D. Catravas

Bioelectrics Publications

The genesis of most older medicinal agents has generally been empirical. During the past one and a half centuries, at least in the Western countries, discovering and developing drugs has been primarily the domain of pharmaceutical companies largely built upon concepts emerging from organic chemistry. Public sector funding for the discovery of new therapeutics has more recently stimulated local, national, and international groups to band together and focus on new human disease targets and novel treatment approaches. This Perspective describes one contemporary example of a newly formed collaboration that was simulated by a regional drug discovery consortium. University of Virginia, …


Editorial: Pulsed Electric Field Based Technologies For Oncology Applications, Siqi Guo, Gregor Sersa, Richard Heller Jan 2023

Editorial: Pulsed Electric Field Based Technologies For Oncology Applications, Siqi Guo, Gregor Sersa, Richard Heller

Bioelectrics Publications

No abstract provided.


Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar Jan 2023

Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar

Chemistry & Biochemistry Faculty Publications

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …


Calpains In The Peripheral Nerve And During Demyelination And Degeneration In Rodents, John A. Miller Jan 2023

Calpains In The Peripheral Nerve And During Demyelination And Degeneration In Rodents, John A. Miller

Browse all Theses and Dissertations

Myelin formed around axons ensures rapid and efficient action potential propagation. Disruption of myelinated axons in the peripheral nervous system (PNS) often causes nerve conduction failure, neurological symptoms and can lead to long-term disability. Calpains are calcium dependent cysteine proteases that play many roles during both normal physiology and pathogenesis. Calpain-1 (CAPN1) and calpain-2 (CAPN2) are key calpain paralogs found in the nervous system and potentially have opposing roles, with CAPN2 having a more neurodegenerative function. In the central nervous system (CNS), calpains have a role in developmental myelination as well as in the pathological demyelination of multiple sclerosis and …


Mouthpiece For Patients With Neuromuscular Disorders, Rebekah Starkey, Carissa Thompson, Michael Dickens, Andrew Pero Jan 2023

Mouthpiece For Patients With Neuromuscular Disorders, Rebekah Starkey, Carissa Thompson, Michael Dickens, Andrew Pero

Williams Honors College, Honors Research Projects

Neuromuscular Disorders (NMDs) impact people throughout the world. An early hallmark of these disorders includes some degree of facial muscle weakness. Respiratory testing is important to evaluate the progression of these patients’ NMDs. However, these tests require that the patient purses their lips around a mouthpiece to create a tight seal. This is a difficult task for one with facial muscle degeneration. This often leads to results that fail to reflect the patient’s true respiratory ability and prevents their physician from providing the appropriate degree of care. The objective of this project was to develop a face mask or mouthpiece …


Verification Of Proton Range Predictions In Proton Treatment Planning Using X-Ray Ct Or Proton Ct Imaging, Nicholas S. Yee Jan 2023

Verification Of Proton Range Predictions In Proton Treatment Planning Using X-Ray Ct Or Proton Ct Imaging, Nicholas S. Yee

Graduate Research Theses & Dissertations

The objective of this paper is to compare the range errors for two treatment plans; one using x-ray CT and the other using proton CT for calculating dose distributions in an animal tissue phantom. We shot 150 MeV proton beam through a meat phantom to a film stack to measure the exponential drop of dose at the Bragg peak until zero dose remained. Plotting the depth dose curves and performing gamma analyses are two ways to quantify the proton range errors when comparing them to depth dose curves from film measurements in the phantom. The depth dose curves give us …


Neonatal Intraocular Injection And Delivery System, Nina Treacher, Cory Ramsey, Marie Kosco, Jackson Carrell Jan 2023

Neonatal Intraocular Injection And Delivery System, Nina Treacher, Cory Ramsey, Marie Kosco, Jackson Carrell

Williams Honors College, Honors Research Projects

The proposed project is a way to deliver liquid medicine into the neonatal eye to prevent retinal detachment with lower risk for bacterial infection and drug misplacement. Currently, ophthalmologists use diabetic needles to introduce medication to the neonate eye. They estimate the injection location with hand-held calipers. This may allow the medicine to be misplaced from poor needle placement and introduce preventable error. The goal is to improve the delivery system ophthalmologists currently use by investigating ways to alter or enhance commonly used injection systems to make the procedure safer and more effective.


Side Cutting Biopsy Needle For Endoscopes, Cade Smarr, Ella B. Brinkman, Christine Skakun, Vincent Grosso Jan 2023

Side Cutting Biopsy Needle For Endoscopes, Cade Smarr, Ella B. Brinkman, Christine Skakun, Vincent Grosso

Williams Honors College, Honors Research Projects

Develop a side cutting biopsy needle that fits through the working channel of the endoscope similar to stereotactic needle with syringe suction to overcome the small biopsy samples due to instrument size limitations. The problem users are facing is that the biopsy samples through the endoscope are small secondary to instrument size limitations. The idea for this problem is to develop a side cutting biopsy needle that fits through the working channel of the endoscope similar to stereotactic needle, syringe suction.


Enhancing Dental Aligners With Direct 3d Printing Manufacturing, Erin Clark, Lauren Ickes, Tyler Madison Jan 2023

Enhancing Dental Aligners With Direct 3d Printing Manufacturing, Erin Clark, Lauren Ickes, Tyler Madison

Williams Honors College, Honors Research Projects

Replacement of thermoforming with direct 3d printed aligners, molding appliances for dental and alveolar movement. Currently the process involved requires 3d printing models and plastic thermoforming, trimming and polishing to fabricate the end product. If possible a product that could be 3d printed that had stress retention, crack resistance, and stain resistance properties delivered in thickness between .030 and .040 inches.


Frostflex, Isaac Edmondson, Caleb Edmondson, Joey Esker, Nadine Salem Jan 2023

Frostflex, Isaac Edmondson, Caleb Edmondson, Joey Esker, Nadine Salem

Williams Honors College, Honors Research Projects

Research has shown that the majority of heat lost during physical exercise leaves the body through the hands, feet, and the face. Our design project seeks to develop cooling glove technology to increase the rate at which heat leaves the body during recovery from physical exertion. The goal of this project was to investigate different ways in which heat absorption through various mediums can be manipulated and scaled into an adaptable, flexible design in which athletes of all levels, from recreational to professional, can improve their physical performance with the use of our gloves. Deliverables include a functional prototype, product …


Kv2.1 Dysfunction Underlies The Onset Of Symptoms In Sod1-G93a Mouse Model Of Als, Andrew J. Deutsch Jan 2023

Kv2.1 Dysfunction Underlies The Onset Of Symptoms In Sod1-G93a Mouse Model Of Als, Andrew J. Deutsch

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease which targets motoneurons (MNs), yet underlying disease mechanisms are not well understood. Evaluating the intrinsic excitability of MNs in ALS could lead to a better understanding of mechanisms causing neurodegeneration. The SOD1-G93A (SOD) model is the most commonly studied animal model of ALS. However, past studies have shown highly conflicting results on SOD MN excitability. Interestingly, I show that depending on the level of membrane depolarization, SOD MNs show opposite results of both hyper- and hypo-excitability. This reveals that differences in the methodology of measuring excitability can heavily impact the study results. …


Lipin1 Improves Membrane Integrity In Dystrophic Muscles Of Mdx Mice, Abdulrahman Jama Jan 2023

Lipin1 Improves Membrane Integrity In Dystrophic Muscles Of Mdx Mice, Abdulrahman Jama

Browse all Theses and Dissertations

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder that affects 1 in 3500 male births worldwide. It is characterized by mutations in the dystrophin gene that results in the loss of functional dystrophin. Dystrophin deficiency leads to instability of the sarcolemma alongside increased inflammation, necrosis and fibrosis resulting in membrane rupture and eventual muscle fiber death. There are currently no effective treatments for DMD. Here we show that Lipin1 expression is significantly downregulated at the mRNA and protein levels in gastrocnemius muscle of mdx mice, the DMD mouse model. Lipin1 has a dual function as a phosphatidic acid phosphatase …


Dna Instability At (Attct) Microsatellites In Human Cells, Venicia Alhawach Jan 2023

Dna Instability At (Attct) Microsatellites In Human Cells, Venicia Alhawach

Browse all Theses and Dissertations

Microsatellites are short tandem repeats of DNA (1-9 nucleotides) that are unstable in the genome. They can expand and contract which leads to mutations and rearrangements that jeopardize genomic integrity. When encountered by a replication fork, repeats of these microsatellites can form non-B DNA structures which cause replication forks to stall and collapse eventually leading to double stranded breaks (DSBs) and replication stress. One form of repair of replication dependent DSBs happens via break induced replication (BIR), a highly mutagenic repair pathway. The main objective of this study is to understand how ATTCT pentanucleotide repeats affect replication and chromosomal instability …


Microsatellite Induced Genomic Instability And Mutagenesis Through Break Induced Replication, Rujuta Yashodhan Gadgil Jan 2023

Microsatellite Induced Genomic Instability And Mutagenesis Through Break Induced Replication, Rujuta Yashodhan Gadgil

Browse all Theses and Dissertations

Faithful DNA replication is essential to maintain genomic integrity. Compromises in this process are among the prime causes of cancer and other genetic disorders. Among several factors that can interfere with error-free DNA replication, the formation of non-B DNA structures by microsatellite sequences is critical. Microsatellites are 1-9 bp long tandem repetitive regions that can form secondary structures like hairpins, triplex, Gquadruplex etc. and undergo expansions due to replication fork stalling to cause several diseases. Hairpin forming microsatellites have been shown to induce DNA DSBs and lead to genetic instability and mutagenesis. The goal of this study is to understand …


Increased Liver Stiffness Promotes Hepatitis B Progression By Impairing Innate Immunity In Ccl4-Induced Fibrotic Hbv+ Transgenic Mice, Grace Bybee, Youra Moeun, Weimin Wang, Kusum K. Kharbanda, Larisa Y. Poluektova, Srivatsan Kidambi, Natalia A. Osna, Murali Ganesan Jan 2023

Increased Liver Stiffness Promotes Hepatitis B Progression By Impairing Innate Immunity In Ccl4-Induced Fibrotic Hbv+ Transgenic Mice, Grace Bybee, Youra Moeun, Weimin Wang, Kusum K. Kharbanda, Larisa Y. Poluektova, Srivatsan Kidambi, Natalia A. Osna, Murali Ganesan

Department of Chemical and Biomolecular Engineering: Faculty Publications

Background: Hepatitis B virus (HBV) infection develops as an acute or chronic liver disease, which progresses from steatosis, hepatitis, and fibrosis to end-stage liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). An increased stromal stiffness accompanies fibrosis in chronic liver diseases and is considered a strong predictor for disease progression. The goal of this study was to establish the mechanisms by which enhanced liver stiffness regulates HBV infectivity in the fibrotic liver tissue. Methods: For in vitro studies, HBV-transfected HepG2.2.15 cells were cultured on polydimethylsiloxane gels coated by polyelectrolyte multilayer films of 2 kPa (soft) or 24 kPa (stiff) …


Mesenchymal Stromal Cells And Alpha-1 Antitrypsin Have A Strong Synergy In Modulating Inflammation And Its Resolution, Li Han, Xinran Wu, Ou Wang, Xiao Luan, William Velander, Michael Aynardi, E. Scott Halstead, Anthony S. Bonavia, Rong Jin, Guohong Li, Yulong Li, Yong Wang, Cheng Dong, Yuguo Lei Jan 2023

Mesenchymal Stromal Cells And Alpha-1 Antitrypsin Have A Strong Synergy In Modulating Inflammation And Its Resolution, Li Han, Xinran Wu, Ou Wang, Xiao Luan, William Velander, Michael Aynardi, E. Scott Halstead, Anthony S. Bonavia, Rong Jin, Guohong Li, Yulong Li, Yong Wang, Cheng Dong, Yuguo Lei

Department of Chemical and Biomolecular Engineering: Faculty Publications

Rationale: Trauma, surgery, and infection can cause severe inflammation. Both dysregulated inflammation intensity and duration can lead to significant tissue injuries, organ dysfunction, mortality, and morbidity. Anti-inflammatory drugs such as steroids and immunosuppressants can dampen inflammation intensity, but they derail inflammation resolution, compromise normal immunity, and have significant adverse effects. The natural inflammation regulator mesenchymal stromal cells (MSCs) have high therapeutic potential because of their unique capabilities to mitigate inflammation intensity, enhance normal immunity, and accelerate inflammation resolution and tissue healing. Furthermore, clinical studies have shown that MSCs are safe and effective. However, they are not potent enough, alone, to …


Fusarium Graminearum Effector Fgnls1 Targets Plant Nuclei To Induce Wheat Head Blight, Guixia Hao, Todd A. Naumann, Hui Chen, Guihua Bai, Susan Mccormick, Hye-Seon Kim, Bin Tian, Harold N. Trick, Michael J. Naldrett, Robert Proctor Jan 2023

Fusarium Graminearum Effector Fgnls1 Targets Plant Nuclei To Induce Wheat Head Blight, Guixia Hao, Todd A. Naumann, Hui Chen, Guihua Bai, Susan Mccormick, Hye-Seon Kim, Bin Tian, Harold N. Trick, Michael J. Naldrett, Robert Proctor

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most devastating diseases of wheat and barley worldwide. Effectors suppress host immunity and promote disease development. The genome of F. graminearum contains hundreds of effectors with unknown function. Therefore, investigations of the functions of these effectors will facilitate developing novel strategies to enhance wheat resistance to FHB. We characterized a F. graminearum effector, FgNls1, containing a signal peptide and multiple eukaryotic nuclear localization signals. A fusion protein of green fluorescent protein and FgNls1 accumulated in plant cell nucleiwhen transiently expressed in Nicotiana benthamiana. FgNls1 suppressed …


Brain Activity Associated With Taste Stimulation: A Mechanism For Neuroplastic Change?, Angela M. Dietsch, Ross M. Westemeyer, Douglas H. Schultz Jan 2023

Brain Activity Associated With Taste Stimulation: A Mechanism For Neuroplastic Change?, Angela M. Dietsch, Ross M. Westemeyer, Douglas H. Schultz

Department of Special Education and Communication Disorders: Faculty Publications

Purpose: Neuroplasticity may be enhanced by increasing brain activation and bloodflow in neural regions relevant to the target behavior.We administered precisely formulated and dosed taste stimuli to determine whether the associated brain activity patterns included areas that underlie swallowing control.

Methods: Five taste stimuli (unflavored, sour, sweet-sour, lemon, and orange suspensions) were administered in timing-regulated and temperature-controlled 3 mL doses via a customized pump/tubing system to 21 healthy adults during functional magnetic resonance imaging (fMRI). Whole-brain analyses of fMRI data assessed main effects of taste stimulation as well as differential effects of taste profile.

Results: Differences in …


การพัฒนาไฮโดรเจลเจลาตินที่มีอนุภาคนาโนทองคำ สำหรับการวัดปริมาณรังสี, ภาวิณี ชูสินธ์ Jan 2023

การพัฒนาไฮโดรเจลเจลาตินที่มีอนุภาคนาโนทองคำ สำหรับการวัดปริมาณรังสี, ภาวิณี ชูสินธ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัจจุบันรังสีรักษามีบทบาทสำคัญในการช่วยรักษาโรคมะเร็ง โดยการให้ปริมาณรังสีสูงสุดที่เนื้อเยื่อมะเร็ง และก่อให้เกิดผลกระทบต่อเนื้อปกติน้อยที่สุด ดังนั้นความถูกต้องของปริมาณรังสีจึงเป็นสิ่งสำคัญ การวัดปริมาณรังสีเป็นสิ่งหนึ่งที่ช่วยยืนยันและสร้างความมั่นใจให้ผู้ป่วยได้ การศึกษาวิจัยนี้ได้พัฒนาอุปกรณ์การวัดปริมาณรังสีในรูปแบบไฮโดรเจลชนิดใหม่ สำหรับการวัดปริมาณรังสี ที่มีคุณลักษณะเฉพาะตัวในการขึ้นรูปได้หลายมิติ และมีความเข้ากันได้ทางชีวภาพจากพอลิเมอร์ธรรมชาติ เช่น เจลาตินและอะกราโรส ผสมกับสารละลายทองคำ โดยอาศัยนวัตกรรมนาโนเทคโนโลยี และการเปลี่ยนแปลงปฏิกิริยาทางเคมีของไฮโดรเจลเมื่อมีการฉายรังสี ทำให้เกิดการสังเคราะห์อนุภาคนาโนทองคำที่มีคุณสมบัติทางแสงที่โดดเด่นและเฉพาะตัวเชิงพื้นผิว ทำให้มองเห็นการเกิดการเปลี่ยนแปลงสีของไฮโดรเจลด้วยสายตาเปล่าได้อย่างรวดเร็วภายใน 10 นาที ภายหลังจากการได้รับรังสี รวมทั้งวัดค่าการดูดกลืนแสงในช่วงปริมาณรังสี 0-5 Gy ด้วยเทคนิคสเปกโตรโฟโตเมตรีที่ความยาวคลื่นดูดกลืนสูงสุดที่ 540 nm พบว่า ปฏิกิริยาทางเคมีภายในไฮโดรเจลเกิดขึ้นได้สมบูรณ์เมื่อได้รับรังสีผ่านไปแล้ว 2 ชั่วโมง โดยมีขีดความสามารถในวัดต่ำสุด คือ 0.37 Gy โดยมีความคงตัวของค่าการดูดกลืนแสงหลังจากได้รับรังสีไปแล้วนานถึง 7-14 วัน รวมทั้งให้ค่าความสัมพันธ์เชิงเส้นตรงของไฮโดรเจลเจลาตินและไฮโดรเจลเจลาตินผสมอะกราโรส เท่ากับ 0.9996 และ 0.9994 ตามลำดับ จากผลการทดลองนี้แสดงให้เห็นถึงความสามารถของไฮโดรเจลชนิดนี้ในการตอบสนองต่อรังสีที่รวดเร็ว ในช่วงปริมาณรังสีต่ำที่ใช้ทางคลินิค ที่มีความคงตัวและความถูกต้องแม่นยำสูง เหมาะสำหรับการนำไปประยุกต์ใช้ในงานรังสีรักษาต่อไป


Measurement Of Fluid Movement Throughout The Brain Via Multiple Magnetic Resonance Imaging Techniques During High-Definition Transcranial Direct Current Stimulation, Jack W. Beaty Mr Jan 2023

Measurement Of Fluid Movement Throughout The Brain Via Multiple Magnetic Resonance Imaging Techniques During High-Definition Transcranial Direct Current Stimulation, Jack W. Beaty Mr

Dissertations and Theses

Transcranial Direct Current Stimulation (tDCS) is a non-invasive method of neuromodulation with applications in neuroscience, clinical care, and biomedical engineering. tDCS has been well established as a safe method of applying low amplitude current between two or more electrodes to alter excitation thresholds and neuroplasticity. Recently, in-vitro and clinical studies have suggested that DC stimulation can induce a transient, polarity-specific, effect of increased water exchange across the blood-brain barrier (BBB). The electroosmotic effect, the proposed phenomenon driving water exchange, is a biophysical response of charged ions moving across an oppositely-charged surface, i.e., the tight junction, when subjected to an electric …


Assessment Of Material Properties In Bone Surrounding Microdamage, Niovi Dollas Jan 2023

Assessment Of Material Properties In Bone Surrounding Microdamage, Niovi Dollas

Dissertations and Theses

Bisphosphonates [BPs] are the mainstay for osteoporosis treatment. They suppress bone resorption/remodeling, preventing bone loss. However, BPs also suppress the beneficial bone remodeling that replaces microscopically damaged bone that occurs from normal mechanical wear-and-tear or fatigue, leading to impaired tissue material properties and in some instances atypical femoral fractures.

In these studies, we assessed the effects of acute fatigue, fatigue induced remodeling, and fatigue microdamage with remodeling suppression using the clinical BP, alendronate [ALN], on local bone material properties. Studies were performed on cortical bone sections from rat ulnae into which fatigue damage had been introduced in vivo. Rat …