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A COMPARISON OF ENDODONTIC ROOT-END FILLING TECHNIQUES: A MICRO-COMPUTED TOMOGRAPHY (micro-CT) ANALYSIS PART II
Full text linkAbstract
A COMPARISON OF ENDODONTIC ROOT-END FILLING TECHNIQUES: A MICRO-COMPUTED TOMOGRAPHY ANALYSIS
Andrew Marra, D.D.S.
Introduction: Researchers have compared many endodontic root-end filling techniques for porosity, though few have used a micro-computed tomography analysis for comparisons. The purpose of this study was to evaluate total porosity volume of three different bio-ceramics filling materials with two techniques--hand compaction versus hand/ultrasonic compaction at an ultrasonic setting of 5% using Micro-CT Analysis.
Methods: Seventy-two human single canaled extracted teeth were selected for the study. All were subjected to orthograde endodontic treatment followed by root tip resection at 3-mm from the apex with a 90° slice to the long axis of the root. A standard retrograde preparation of 3-mm depth was created with an ultrasonic tip with a setting of 5%. Samples were assigned to six groups (n = 12 per group) according to the filling material and method used: ProRoot® MTA compacted by hand alone; ProRoot® MTA compacted by hand/ultrasonic compaction; Biodentine® compacted by hand alone; Biodentine® compacted by hand/ultrasonic compaction; EndoSequence® BC putty compacted by hand alone; and EndoSequence® BC compacted by hand/ultrasonic compaction. Teeth were scanned with micro-CT to evaluate total porosity volume. A Wilcoxon test was conducted to determine if there was a difference between the groups compacted by hand alone and the hand/ultrasonic compaction group.
Results: The results did not show a significant difference between the total of hand compaction alone versus the hand/ultrasonic compaction (p-value = 0.603). There was no significant difference between each material when comparing hand compaction alone versus hand/ultrasonic compaction. MTA (hand compaction alone versus hand/ultrasonic compactions) yielded a p-value of 0.318, BD (hand compaction alone versus hand/ultrasonic compactions) yielded a p-value of 0.443, and BC (hand compaction alone versus hand/ultrasonic compactions) yielded a p-value of 0.378.
Conclusion: Within the limitations of this in vitro study, both hand compaction alone and hand/ultrasonic compaction resulted in similar total porosity volume
Individual and collective properties of tunable photochemical Belousov-Zhabotinsky micro-reactors
Full text linkCell-like model chemical systems are powerful tools that can be used to explore the role of intercellular coupling on population level behaviors in communities of biological cells. Firstly, we present a new method for fabricating such micro-reactors using the photosensitive Belousov–Zhabotinsky (BZ) reaction system employed in silica microparticles. These BZ micro-reactors have a tunable response to photochemical coupling, varying from a fully excitatory response to a fully inhibitory response. Their response can be tuned through variations in either the reactive mixture or, on an individual micro-reactor level, by changes in the synthesis temperature used during the fabrication of the silica micro-reactors. We observe fully inhibitory behavior for micro-reactors synthesized at 22 °C and fully excitatory behavior for micro-reactors synthesized at temperatures ≥ 40 °C. A five-variable photosensitive Oregonator model is used to explore the physicochemical properties of the microparticles that lead to their tunable behavior.
We then investigate collective behaviors associated with coupling inhibitory and excitatory micro-reactor networks using light. In this work we utilize the inhibitory properties of MOs synthesized at 22 °C and excitatory properties of MOs synthesized at 40 °C. Bi-stable synchronization and cluster states are observed with small networks consisting of two and three globally coupled oscillator networks. The dimensionless three-variable Zhabotinsky-Buchholtz-Kiyatin-Epstein (ZBKE) model of the BZ chemical system is used in simulations.
Finally, we investigate the effect of temperature on the photochemistry of the BZ reaction. We demonstrate a change in the phase response as the BZ reaction temperature is increased. For BZ mixtures which show excitatory and mixed behavior at 0 °C, a change to close to inhibitory behavior is observed when the BZ reaction temperature is changed to 20 °C
Extending Effects of the Good Behavior Game with Mixed Schedules
Full text linkStudent disruptive behavior in the classroom can adversely affect both students and teachers. The Good Behavior Game (GBG) is a well-established classroom management strategy used to reduce disruption. However, its use remains limited due to implementation barriers reported by teachers, such as effort associated with delivering feedback, and the limited generalization of the GBG effects to times when the game is not in place. The current study had two main objectives: (a) to evaluate whether a modified version of the GBG implemented on a mixed-schedule-like arrangement (MIX GBG) could reduce student disruption as effectively as the standard version (MULT GBG), and (b) to examine if the effects of the MIX GBG extended to periods in which the game was not in place. Both versions of the GBG were implemented in two elementary school classrooms. Results showed that MIX GBG produced reductions in overall disruption only in one classroom, while MULT GBG was effective in both classrooms. Teachers and students preferred MULT GBG over MIX GBG. Further research should investigate the effectiveness of MIX GBG and continue to evaluate the individual role of each component of the GBG to improve contextual fit and reduce implementation barriers
Efficacy of Salmonella Surrogate Enterococcus Faecium in Poultry and Mash Broiler Feed
Full text linkThis dissertation investigates the efficacy of Enterococcus faecium as a surrogate for Salmonella in validating thermal inactivation processes during poultry feed manufacturing and meat processing. The research encompassed three studies evaluating microbial kinetics in mash broiler feed, reconstructed ground chicken, and predictive modeling approaches to improve food safety interventions. In the first study, the thermal resistance of nalidixic acid-resistant Salmonella Typhimurium and E. faecium was compared in mash broiler feed heated at 75–95°C. Results demonstrated that E. faecium exhibited significantly greater heat resistance than Salmonella, with longer shoulder times, greater tailing effects, and higher D-values, supporting its use as a conservative surrogate for validating feed pelleting processes. The second study examined the effects of temperature and salt concentrations on the thermal inactivation of both microorganisms in reconstructed ground chicken meat. Heating at 62–74°C revealed that increased salt levels enhanced Salmonella’s thermal resistance at lower temperatures but reduced survival at higher temperatures. Across all treatments, E. faecium consistently showed higher resistance, reinforcing its suitability as a surrogate. Machine learning models, including Random Forest and Support Vector Regression, effectively predicted microbial reductions, highlighting temperature and exposure time as the most critical factors influencing inactivation. Collectively, these findings provide robust evidence that E. faecium can serve as a reliable, conservative surrogate for Salmonella in both poultry feed and meat products. The kinetic models and predictive tools developed herein offer the poultry industry practical guidance for designing and validating thermal processing interventions aimed at reducing foodborne pathogen risks and enhancing consumer safety
Identifying Factors Associated with Time to Diagnosis for Symptomatic Intestinal Malrotation in Pediatric Patients
Full text linkIntestinal malrotation is a rare condition in which the intestines rotate improperly during embryonic development. Intestinal malrotation is typically diagnosed in pediatric patients with an upper gastrointestinal imaging (UGI) series. Longer time to diagnosis of intestinal malrotation increases the risk of mortality and severe morbidity. While the need for timely diagnosis is well-established in the literature, the correlates of time to diagnosis are largely unknown. The classic medical presentation for intestinal malrotation is an infant presenting with green bilious emesis. I hypothesize that time to diagnosis of intestinal malrotation will be longer in symptomatic pediatric patients when they present differently from the classic presentation (i.e., older pediatric patients not presenting with green bilious emesis) or those who lack access to an UGI due to living in a rural area. This retrospective secondary data analysis project will use the Intestinal Malrotation Outcomes and Wellness Registry (IMPOWER) data to identify factors associated with time to diagnosis of IM from symptom onset in pediatric patients. The rationale for this project is that once the factors associated with time to diagnosis of intestinal malrotation are identified, they can be used to create interventions to reduce time to diagnosis and identify alternative diagnostic screening methods
A Quality Improvement Project to Assess the Impact of a Patient Acuity Tool on Nurse Satisfaction in Equitable Patient Assignments in Nurse Workload and Perceived Quality Care Provided
Full text linkBackground: Traditional nursing staffing models used to create patient-care assignments do not account for patient acuity. As patient acuity increases, nurse workload increases. When patient-care assignments do not account for acuity, nurses are unable to provide quality care to patients. Utilizing a patient acuity tool (PAT) has been shown to improve nurse satisfaction and equity in assignments while also enhancing the ability for nurses to provide quality care.
Purpose: The project aims to assess the impact of a PAT to improve nurse satisfaction in equitable patient assignments based on nurse workload and perception of quality of care provided to patients by 25% in a three-month period, following the implementation of a revised PAT.
Intervention: Revise the collection process of previously implemented PAT to include bedside and charge nurses and evaluate improvement by pre-and post-surveys assessing perception of equitable patient assignments and nurse satisfaction. Nursing staff was educated on the revised PAT and collection process.
Methods: This project was conducted on a 24-26 bed medical-surgical long-term antibiotic unit at J.W. Ruby Memorial Hospital, in Morgantown, West Virginia. Participants included all consented nursing staff on the unit. The IHI model for quality improvement was used to develop and guide the quality improvement project to improve nurse satisfaction.
Results: The post-survey analysis demonstrated over 25% improvement in nurse satisfaction following the PAT intervention in creating equitable patient assignments in nurse workload and improved perception of quality care provided.
Conclusion: The implementation of a unit specific nurse-driven PAT is a cost-effective tool that incorporates input from both bedside nurses’ and charge nurses on patient acuity and workload. A PAT assists in decision-making to create equitable patient assignments in relationship to workload and quality care provided to improve nurse satisfaction
Long-term trends in Brook Trout production and large wood in West Virginia headwater streams
Full text linkProjects which monitor long-term trends in ecosystems are uncommon but extremely important in the management of fish and wildlife populations. By assessing the health of a population or community over multiple temporal scales, these projects provide true insight into population success that cannot be elucidated through short-term studies. Long-term projects are also instrumental in assessing the effects of disturbance events as they provide valuable baseline information which can be compared to data collected post-disturbance. Even more importantly, long-term studies can help identify crucial changes in the health and success of imperiled and invaluable species to improve and focus conservation efforts.
One such species, the Brook Trout, Salvelinus fontinalis, was the focus of this thesis. In the central Appalachians, few fish are as beloved or as important, economically and ecologically, as the Brook Trout. The only stream trout native to the eastern United States, Brook Trout are desirable and iconic target for anglers. The species is also a top predator in headwater stream ecosystems and impacts the biotic community at multiple levels. However, anthropogenic disturbance over the past century has resulted in significant declines in the abundance and distribution of Brook Trout across their range. To conserve the species, managers must have accurate information regarding the long-term health of Brook Trout populations and the ways in which those populations vary across the landscape. In fisheries management, metrics like abundance and biomass are often used to evaluate population success in this way; however, other metrics are available which may be able to measure the health of Brook Trout populations more accurately.
Secondary production, the biomass produced in an area over time, is a useful but underutilized metric for the evaluation of fish populations. As it is a rate, it naturally encompasses temporal changes in population health better than static metrics like abundance. However, as each production estimate requires multiple sampling events and detailed information about cohort size, production is rarely calculated by agencies or used to make management decisions. As such, typical Brook Trout production estimates and the factors that might affect production in the region are unknown. Likewise, prior to this thesis study, it was not yet known whether the broad decline in Brook Trout abundance documented throughout their range had impacted Brook Trout production in headwater central Appalachian streams. Therefore, the overarching aim of this thesis was to evaluate changes in Brook Trout production over the past two decades and in response to various changes in their environment. To do this I used data collected as part of a long-term Brook Trout monitoring project which began in 2003. This project encompassed 25 headwater Brook Trout streams in east-central West Virginia which were sampled annually to quantify their biotic community and the availability and quality of fish habitat. The breadth of this long-term monitoring project, both spatially and temporally, provided unique insight into the spatial and temporal variability that Brook Trout populations in the region experience.
In my first chapter, I aimed to fill current knowledge gaps by quantifying annual Brook Trout production in the 25 study sites monitored annually and in two additional larger sites which also contained Brook Trout. Then, I used environmental data collected as part of the longterm project or collected by other agencies also monitoring the study sites to determine what factors were driving variability in Brook Trout production over time and across the landscape. Mean annual Brook Trout production in the study sites was 0.920 g/m2 /yr, much lower than many other published estimates of salmonid production and indicative of low overall productivity in the study sites. I also detected significant declines in Brook Trout production over time, driven primarily by changes in summer precipitation and increased Beaver Castor canadensis activity. Spatial variability in production was primarily driven by surficial geology, though additional factors like elevation, canopy cover, and habitat played a role.
The second chapter of this thesis focused on the response of Brook Trout populations and instream habitat to a significant disturbance event. Superstorm Sandy, a major Atlantic hurricane, struck the study sites in October of 2012, midway through the monitoring project. A previous study on the impact of superstorm Sandy found significant increases in large wood (LW) loads in the study sites immediately following the storm. I examined long-term trends in LW loads and Brook Trout production in the study sites based on the magnitude of those impacts and found no long-term difference in either parameter when comparing streams significantly impacted by Sandy and those hardly touched. However, I also identified a slight but significant decline in LW loads in the study sites over the past two decades, possibly driven by historic changes to the riparian forest from widespread logging in the early 20th century. These results serve as valuable baseline data for the conservation of Brook Trout in central Appalachia and highlight the value of long-term monitoring projects. Without two decades of relevant data, the trends in fish populations and their habitat I detected would have been difficult, if not impossible, to identify. Moving forward, other studies evaluating the production of Brook Trout or other species present in the region will have comparable literature to reference. Conservation efforts can now be focused on those streams and populations most at risk of habitat loss and population decline
Xanthine Oxidoreductase, Uric Acid, and Iron Homeostasis: Discovering a Therapeutic Vulnerability in Breast Cancer
No full textBreast cancer remains the most frequently diagnosed malignancy and the leading cause of cancer related deaths in women. This is primarily due to distant metastases, which highlight the necessity to understand factors that contribute to breast cancer progression. Emerging evidence associates decreased tumor xanthine oxidoreductase (XOR) expression with a poorer prognosis, increased recurrence, and a more aggressive phenotype. While healthy liver, intestines, kidneys, and breast tissue have robust XOR expression and activity, there is a tendency for this to be ablated in carcinogenesis. This dissertation investigates XOR\u27s role in breast cancer and identifies its product, uric acid (UA), as possessing anticancer properties. Previous studies indicate UA has antioxidant roles, including chelation of iron, an essential nutrient for cancer cell survival. Our study establishes that clinically relevant concentrations of UA decrease breast cancer cell proliferation, migration, and survival, which is restored by iron supplementation. These effects were not observed in nontumorigenic or primary mammary epithelial cells, which indicates a cancer cell specific vulnerability to UA. Additionally, inhibiting the UA efflux transporter ABCG2, also known as BCRP, sensitized the breast cancer cells to lower concentrations of UA, affirming its promise as a therapeutic target. These findings support the hypothesis that breast cancer cells downregulate XOR expression to decrease intracellular UA accumulation and mitigate iron sequestration. In addition, our work highlights the therapeutic potential of targeting ABCG2 alone or as a combination therapy. Furthermore, we have confirmed that our observations in breast cancer cells extend to hepatocellular carcinoma, where we reveal HepG2 cells lack XOR expression and activity. When taken together, this thesis reveals a novel fundamental mechanism for altering cancer cell growth by modulating intracellular UA levels
3D Printed Microfluidic Platforms for ELISA-Based Diagnostics: Advancing Toward Point of Care
No full textProtein biomarker detection is a critical analytical method for quantifying proteins in biological samples. It is relevant not only in medical diagnostics and research but also numerous other fields such as environmental monitoring, pharmacology, food safety, and biotechnology. Sensitive detection at picogram-per-milliliter (pg/mL) levels is essential for diagnosing diseases, monitoring progression, and tailoring treatments, especially for low-abundance biomarkers like troponin, interleukin 6, carcinoembryonic antigen (CEA), activin A, and vascular endothelial growth factor (VEGF). Immunoassays, particularly enzyme-linked immunosorbent assays (ELISAs), are the gold standard for protein biomarker detection due to their high specificity and sensitivity. The development of point-of-care (POC) diagnostic platforms capable of delivering rapid, accessible, and cost-effective results outside traditional laboratory settings enables timely interventions and expanding diagnostic capabilities to resource-limited areas. The advancement of POC immunoassays relies heavily on innovative device design and surface chemistry to enhance sensitivity, specificity, and usability. The field of 3D printing has been greatly growing over the last decade in terms of device fabrication and application. This fabrication technique offers many advantages over traditional methods that can be taken advantage of to further improve biomarker detection. This work collectively explores the development of 3D-printed microdevices integrated with novel surface modification strategies to improve ELISA for POC applications. In Chapter 2, we establish a surface modification protocol involving air plasma activation followed by GLYMO-labeled streptavidin incubation, which significantly enhances antibody immobilization on various commercial photocurable resins. This strategy improves ELISA performance on both microwells of varying size and microchannels, achieving detection limits comparable to conventional commercial plates. Building on this, Chapter 3 presents a 3D-printed cPlate device coupled with the surface modification method that eliminates the need for magnetic beads, enabling both single biomarker analysis and multiplexed detection within a single device. The immobilization of GLYMO-modified streptavidin and capture antibodies along with the 3D printed fluid manipulation achieved with the cPlate design simplifies ELISA protocols for users and advances the potential for multiplexed POC diagnostics. To address challenges in nonspecific binding and washing steps crucial for POC use, Chapter 4 introduces a liquid-infused surface (LIS) treatment alongside a “key” and well device fabricated through high-resolution LCD printing. This design enables controlled reagent incubation and washing without complex user actions. Functional ELISAs for Activin A detection were optimized on the 3D printed POC ELISA device through the use of the GLYMO surface modification strategy, confirming reproducible, semi-quantitative biomarker detection. Together, these integrated advances in surface chemistry, device architecture, and assay protocols mark significant progress toward practical, sensitive, and user-friendly 3D printed POC ELISA platforms for biomarker detection in healthcare diagnostics. However, in Chapter 5, future directions are discussed on how to further advance this research. One focus would be on the integration of the LID surface with the GLYMO surface modification strategy in the 3D printed POC ELISA device to investigate the capability of going beyond semi-quantitative analysis. Eventually studies will also look into the possibility of adapting the readout methods so that no complex instrumentation is required for the POC setting. Lastly, the potential to turn this into a feasible POC diagnostic test would also then require more investigation of scalability and long-term stability
An Investigation into Energy Consumption and V2G Potential of an Electric School Bus Fleet
No full textThe transition towards sustainable public transportation demands detailed evaluation of alternative fuel technologies. This thesis presents a comprehensive energy assessment and comparative analysis of diesel and electric school buses (ESBs) operating within the Monongalia County school district, its Vehicle-to-Grid (V2G) potential, and efficiency analysis of charging system. Utilizing real-world operational data collected from buses running identical routes, the study quantifies and compares their mileage specific energy consumption. The analysis reveals an average fuel economy of approximately 6.17 miles per gallon (MPG) for the conventional diesel school bus, contrasted with an average energy consumption rate of 0.46 miles per kilowatt-hour (miles/kWh) for the ESB based on the evaluation period of September,2024 – December,2024. Further investigation into the effect of environmental factors shows the dependency of MPG and miles/kWh to ambient temperature; ESB energy efficiency (measured in miles per kWh) showed a tendency to slightly improve with increasing temperatures (Tair\u3c 30 °F), whereas diesel bus MPG exhibited a decrease, potentially due to increased auxiliary loads such as air conditioning systems. However, the carbon dioxide emissions per mile from ESBs are slightly higher than that of diesel buses mainly due to coal-based electricity in West Virginia.
Beyond direct energy consumption, the research investigates the technical and economic potential of V2G system through the detailed analysis of EV fleet focusing on energy, carbon emissions, and cost savings using bi-directional charging technology. The full electrification of fleet has the potential to deliver 14, 929 kWh of electricity when charged from 20% and 80% SOC and provide 14,929 kW Stable electricity with V2G when the electricity is discharged back to the grid in one hour. The ESB fleet showed strong V2G potential with 7.34 million cost for bilateral chargers affects financial viability. Addition to that, the study assessed the performance of charging infrastructure with direct measurement of a 120 kW Level 3 DC fast charger which yielded a grid-to-vehicle energy transfer efficiency of 95.21% providing important data on energy losses during the charging process. The long idle time of L3 DC charge will negatively affect the energy utilization efficiency of EV chargers.
Collectively, these findings provide an overall picture of operational performance, environmental dependencies, grid interaction potential, and charging efficiency associated with ESBs in a real-world setting and will serve as a valuable reference for assessing the viability of ESB, and V2G capable ESB fleet