Boston University Theses & Dissertations
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This is the master collection of contemporary BU theses and dissertations. We plan to consolidate school- and college-specific collections into this one, and add school- and college-specific metadata to enable users to browse appropriately.
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Item Comparison of surgical techniques to accelerate orthodontic tooth movement: a review(2024) Lemoine, Jesse Abreu; Kernitsky, Jeremy; Price, AlbertBACKGROUND: Accelerating orthodontic treatment is a priority for clinicians and patients aiming to reduce treatment duration and associated discomforts. This systematic literature review assesses the current evidence regarding the efficacy of surgically assisted acceleration techniques in orthodontics. MATERIALS AND METHODS: In November 2021, an extensive search was conducted across EMBASE, Cochrane, and PubMed databases, yielding a total of 2,022 articles. After application of selection criteria and full text analysis the articles for review, were narrowed down to a total of 26 entries. These studies included Piezocision, Propel, Micro-osteoperforations (MOP), Periodontally Assisted Osteogenic Orthodontics (PAOO), and laser-assisted techniques as interventions. RESULTS: The scrutinized literature revealed that 75% of articles on Piezocision reported a favorable impact on treatment time, whereas MOP was found effective in half of the related articles. The Propel system was deemed beneficial in only 25% of the studies examined. In contrast, both articles evaluating PAOO unanimously found it to be an effective method for accelerating orthodontic tooth movement. CONCLUSION: Our review indicates a significant variance in the success rates of surgically assisted orthodontic acceleration methods, with Piezocision and PAOO displaying the highest efficacy, 1.5-2x faster than control groups. Risk of bias assessment revealed moderate to high risk across our selected studies, with the most common issues including lack of blinding of participants and assessors as well as inconsistent reporting of outcomes.Item Shear bond strength of different cements to printed resins and zirconia(2024) Allanqawi, Rawan Taleb; Giordano, RussellOBJECTIVES: This in-vitro study aimed to measure bonding of multi and single step cements to printed resins and Layzir zirconia. Evaluate the effect of different material combinations on shear bond strength, and to evaluate the effect of thermocycling on shear bond strength of different materials combinations. MATERIALS AND METHODS: Rectangular specimens (N= 384) were prepared from PacDent Rodin Sculpture 2.0 (RS), SprintRay Ceramic Crown (SCC), Rodin Titan (RT), and Layzir Zirconia (LZ), and were divided into 16 groups according to material combinations, static or thermal aging process. Stainless-steel rods (Shofu Dental Corporation) of 4 mm diameter were used for this in-vitro study. Shear bond strength (SBS) test was performed on all static and thermocycled groups. The final dimension of each plate was about 15 mm in length, 2mm thick, and 15 mm in width. 3D printing of resins was done using the Asiga 3D printer. Layzir Zirconia specimens were prepared by sectioning the zirconia disc using the Isomet 5000 sectioning machine. Zirconia specimens were dried in the oven and sintered using a high temperature furnace (Zircar). All materials were surface treated based on material recommendations. All stainless-steel rods and Layzir Zirconia were sandblasted, PacDent Rodin Sculpture 2.0 and Rodin Titan were etched with hydrofluoric acid 5%, and SprintRay Ceramic Crown was sandblasted and etched using 5% Hydrofluoric acid. In the last stage of specimen preparation, the framework plate was placed on a flat surface, then the adhesive resin cement was injected to fill the bonding area. Excess cement was removed around the rod border with a plastic instrument and a micro brush, and the bonded plate/rod was kept under a static load of 1.4 kg for 10 minutes. Half of the specimens were tested in a control/static condition, and another half were thermal aged for 5000 cycles before shear bond testing was done. A shear bond test was performed on all static and thermocycled specimens by using the universal testing machine (Instron Model 5566A). The crown material was secured into a jig and a flat shear blade was used to shear the pins. The blade had a perpendicular contact at the interface between the rod and the plate. A load was applied at the adhesive interface between the plate/rod during the testing. The shear bond strength was calculated in MPa by load of failure over the area of the bond. The maximum shear load was recorded at debonding. Specimens were examined to determine failure location, load to failures values were also analyzed as well as the mode of failures. RESULTS: This study showed a significant difference in shear bond strength between the printed resin groups compared to Layzir Zirconia group (P<.0002). Layzir Zirconia group showed the lowest SBS mean values among the tested groups (16.18 MPa). SprintRay bonded with Panavia SA materials produced the highest shear bond strength mean values (32.07MPa), followed by Rodin Titan bonded with Panavia V5 and Clearfil (30.91MPa) and Panavia SA (29.50 MPa), and PacDent Rodin Sculpture 2.0 Bonded with Panavia SA (25.51 MPa). The lowest shear bond strength mean values were recorded in SprintRay bonded with Clearfil and Panavia V5 (17.26 MPa), Layzir Zirconia bonded with Rodin bond and Panavia V5 (15.06 MPa), and Pacdent Sculpture 2 bonded with Clearfil and Panavia V5 (13.62 MPa). There was a significant difference in SBS between control and treated (thermal cycle) groups (decrease in treated group than control group) (P<.0001). There’s a significant difference between SBS values for specimens bonded with Panavia SA compared to other resin cements used (P<.0001). CONCLUSION: Significant differences were found between 3D printed resins compared to Layzir Zirconia groups. Layzir Zirconia groups showed the lowest SBS among all tested groups. Thermal aging significantly decreased SBS values of thermocycled groups. Adhesive failure was the primary mode of failure among all SBS tested groups. Material surface topography, filler content, surface pretreatment and adhesive techniques, as well as thermal aging impact the bonding and as a result SBS values of specimens.Item Investigations of novel endodontic sealers and modifications of existing bioceramic sealers(2024) Gunarajasingam, Ayinkeran; Giordano, RussellThe advent of modern bioactive sealers have introduced the ease of obturation with sealers that possess bioactive properties when used to obturate an endodontically treated canal. With increase use comes increased questions about the efficacy that these sealers have in obturating canals (1). From unpredictable setting time to questions about their ability to obturate and occlude dentinal tubules many questions and criticisms have arisen with their increased popularity. In light of these concerns this study sought to find if there alternative materials with bioactive properties that might adequately obturate an endodontically treated canal. The second part of this project sought to determine if the particle size of an existing bioceramic sealer and determine if the particles of the premixed bioceramic sealer could be reduced to size small enough to potentially obturate dentinal tubules (25). Objective 1. : The first objective of this study was to determine if commercially available pulpal liners and crown and bridge cements could be used to seal endodontically treated canals. Objective 2: the second objective of this project was to determine if reduction in particle size could improve the properties of an existing sealer. Materials and Methods: One pulpal liner, Activa (Pulpadent), one crown and bridge cement Ceramir (Doxa), and EndoSequence BC sealer (Brasseler) were evaluated to determine if the repurposed materials could seal an endodontically treated canal with Endosequence as the control. The second part of this study modified a commercially available powder and liquid sealer, BioRoot (Septodont) BC sealer, to decrease its particle size and evaluated if this modification had any affect on its physical properties. 45 single-rooted teeth were decoronated, endodontically treated, and obturated using one of the commercially available products (n=3) Activa, Ceramir, Endosequence. The modified sealers were separated into groups by the time the powdered sealer was milled using a Speedmixer: 0 seconds (control), 40 seconds, 60 seconds, 120 seconds, and 240 seconds. Data was analyzed using a one-way ANOVA and all pairs comparison using a post-hoc Tukey-Kramer HSD test. Results: Of the repurposed materials Activa showed the most promising results with a setting time of 2.5 ± 0.9 hours as well as the best performance in terms of flow, film thickness, bond strength, and leakage resistance. For the modified sealers the mechanical properties increased as the milling times were increased for all except shear bond, where bond strength peaked at 7.9 ± 6.9 MPa for 120 seconds of milling time. Conclusion: we were able to determine that Activa a pulpal liner demonstrates superior performance in terms of shear bond strength, dye-leakage prevention, setting time, film thickness, flow compared to EndoSequence bioceramic sealer. We were also able to successfully decrease the particle size of an existing bioceramic sealer and were able to show that this improved the setting time, film thickness, flow, and dye-leakage prevention, we were not able to show that it appreciably increased the bond strength of BioRoot bioceramic sealer to dentine in the root canal space.Item Evaluation of the mechanical and the physical properties for resin 3D printed material and machinable composite(2024) Alhussain, Musstafa Musa; Giordano II, Russell; Fan, YuweiOBJECTIVES: This in vitro study assessed the mechanical and physical properties of various 3D-printed resin materials and a machinable hybrid resin. MATERIALS AND METHODS: Eight 3D printing resin materials were selected for evaluation: Pac-Dent Rodin Sculpture 2.0 (RS), Pac-Dent Rodin Titan (RT), BEGO VarseoSmile Crown Plus (BVS), Desktop Health Flexcera Smile Ultra Plus (DHF), SprintRay OnX tough 2 (SROnX), SprintRay Ceramic Crown (SCC), Saremco Crowntec (SC), GC Dental Cerasmart Universal 270 (CS). These materials were tested to evaluate their flexural strength, flexural modulus, biaxial flexural strength, thermocycling, fatigue, fracture toughness, and wear resistance. The specimens still intact after thermocycling and fatigue were subjected to a biaxial flexural strength test. A DLP 3D printer, Asiga Max, was used to print 12 specimens from each printable material to determine three-point flexural strength, biaxial flexural strength, and fracture toughness using a single-edge V-notched beam. and wear resistance was measured using a pin on plate two-body system. The pins acted as test material, and VitaMKII was used as the tooth analog plate material. For the machinable block, bar specimens were prepared by sectioning with an Isomet 5000 diamond saw. A core drill press was also used to prepare pins of the specimens for wear resistance testing and discs for biaxial flexural strength, thermocycling, and fatigue tests. The filler weight percentage of each material was determined using the ash-burning method. The microstructure of a wear rod from each material was examined under a scanning electron microscope (SEM), and the elemental composition was investigated by Energy Dispersive Spectroscopy (EDS). To compare means, a one-way ANOVA (α=0.05) with Tukey's HSD posthoc tests was performed using Excel 365 and JMP Pro 17. RESULTS: Utilizing the three-point method, the flexural strength test results reveal significant differences among the materials tested. The flexural modulus also exhibited significant differences, with the highest to the lowest average observed in CS, RS, SCC, SC, RT, BVS, SROnX and DHF, measuring 8.23, 8.20, 7.33, 6.70, 6.63, 5.65, 4.84 and 4.47 GPa, respectively. The resin materials with the highest biaxial flexural strength were DHF, which demonstrated the highest mean value of 236.89 MPa, followed by CS 229.13 MPa and SROnX 216.85 MPa, with no significant distinction. CS exhibited the highest biaxial flexural strength at 205.52 MPa, while BVS demonstrated the lowest at 117.29 MPa. The thermocycling test presented no significant differences in strength between SROnX, DHF, CS, SC, and SCC. In contrast, BVS displayed the statistically lowest biaxial flexural strength. The fracture toughness test presented no significant differences between CS, RT, and SCC, with values of 3.18, 2.74, and 2.63 MPa·m^0.5, respectively, exceeding the remaining materials. In the wear test, SC showed the least weight loss of 0.0025 g, and SC exhibited the smallest height reduction of 0.040 mm after undergoing the same number of cycles. In contrast, SROnX experienced the highest weight loss of 0.0051 g and height reduction of 0.091mm after 200k cycles. CONCLUSION: The study results demonstrate significant differences in the mechanical properties of 3D-printed resin materials compared to machined hybrid resin materials. These properties included flexural strength, flexural modulus fracture toughness, wear resistance, biaxial flexural strength before and after thermocycling, and cyclic fatigue.Item Oral health among children with failure to thrive(2024) Milaeh, Rua Sameer A.; Discepolo, Keri; Chiao, ChristineThis study investigated the relationship between Failure to Thrive (FTT) and oral health in children, focusing on the influence of medical, dietary, and environmental factors on Early Childhood Caries (ECC) and Severe Early Childhood Caries (S-ECC). A significant gap in U.S. studies concerning the relationship between nutritional status and dental caries, particularly in children aged 0-5 years, highlights the need for more focused and diverse research. A retrospective evaluation of medical records from Boston Medical Center's Growth Clinic examined children diagnosed with FTT from January 2018 to December 2022 and investigated the prevalence of dental caries in these children. The control group consisted of typically developing children matched by age, gender, and insurance status. Data analysis included descriptive statistics and Chi-Square tests to explore differences in demographics, dietary factors, and oral health outcomes between the groups. Results indicated similar gender ratios and predominant public insurance usage in both groups. The FTT group showed a higher incidence of environmental factors contributing to their condition, a greater dependency on bottle feeding and soft diets, and poorer oral hygiene. These factors also correlated with a significantly higher prevalence of ECC and S-ECC compared to the control group. The study uncovered significant environmental and dietary influences on the oral health of children with FTT. It underscored the importance of integrating oral health evaluations and treatments into care strategies for children with FTT given the strong association between FTT and adverse dental outcomes. Limitations of the retrospective approach and sample size are discussed, with recommendations for future prospective studies and larger sample sizes. Applications for clinical practice focused on enhancing healthcare accessibility and integrating updated training for providers to ensure effective management of FTT in children.Item Fabrication of polymer infused multiphase glass ceramic block(2024) Kantikosum, Kirana; Giordano, Russell A.OBJECTIVES: This study aims to fabricate polymer infused multiphase glass ceramic block and explore mechanical properties, optical properties and physical properties of the ceramic block. MATERIALS AND METHODS: Polymer Infused Multiphase glass ceramic specimens were prepared with the slip-casting technique. The specimens were divided into 3 groups based on different sintering temperatures: Group 1) 850 °C, 2) 880 °C, and 3) 900 °C. After sintering, density before resin infiltration of specimens was measured and calculated. All specimens were immersed in silane solution and infused with resin solution then cured under Hydraulic press. Specimens were examined for physical optical and mechanical properties including microstructure, crystal characterization, biaxial flexural strength, translucency parameter and contrast ratio. All data underwent one-way of variance (ANOVA) and Tukey HSD test for comparisons with a significance threshold set at a p-value of <0.05. RESULTS: A slip casting technique was effectively employed to fabricate a multiphase glass ceramic material, followed by resin infusion and curing under isostatic pressure. Biaxial flexural strength variations were observed among specimens subjected to different sintering temperatures, as evidenced by testing with a universal testing machine. Additionally, spectrophotometer analysis revealed no statistically significant differences in translucency parameter and contrast ratio among groups of specimens sintered at varying temperatures before polymer infiltration. However, there is a statistically significant difference among groups after polymer infiltration. Scanning Electron Microscope images confirmed the presence of resin interpenetrating networks within the specimens. Notably, the properties of the specimens were significantly influenced by the sintering temperature. CONCLUSION: 1. Polymer Infused Multiphase glass ceramic material can be fabricated from the combination of resin infused ceramic and feldspathic porcelain. 2. Different sintering temperatures show no influence on the density of polymer infused multiphase glass ceramic materials, both before and after resin infiltration. 3. Different sintering temperatures show no influence on translucency parameter, contrast ratio of polymer infused multiphase glass ceramic materials before resin infiltration. 4. Resin infiltrated networks sintered at 900°C exhibit lower biaxial flexural strength and translucency parameter compared to polymer infused multiphase glass ceramic material sintered at 850°C and 880°C. 5. Resin infiltrated networks sintered at 900°C exhibit superior contrast ratio compared to polymer infused multiphase glass ceramic material sintered at 850°C and 880°C. 6. Scanning Electron Microscope images reveals interpenetrating networks in the polymer infused multiphase glass ceramic material.Item Econometric analysis of heterogeneity in financial markets using quantile regressions(2018) Tian, Yuan; Qu, ZhongjunThis dissertation studies heterogeneity in financial markets using quantile regressions. The first chapter develops uniform confidence bands for the linear quantile regression estimator in a time series setting. The confidence bands are important for estimating the precision at different quantiles of the conditional distribution. The inference procedure is carried out through bootstrapping and allows for serially correlated error terms. An empirical application to the relationship between stock returns and investor sentiments suggests the method can be informative. The second chapter analyzes the heterogeneity of firm characteristics on returns to capital. It develops a theoretical model under a utility maximization framework with imperfect insurance and credit markets constraints. From the model, the returns to capital are derived as a function of the parameters, which affects the production function of the firm and the entrepreneur utility form. Quantile regression is applied to analyze the field experiment data from the Sri Lanka Micro Enterprises Project (2005-2010). Empirical evidence shows that returns vary across different quantiles of firm profits. Further, the ability/risk aversion of entrepreneurs affect the returns differently at different quantiles. The third chapter examines capital account liberalization and its effect on price volatility in the Chinese housing market. The chapter assesses the extent to which: a) short-term capital flows and foreign direct investment may have impacted prices and volatility in the Chinese housing market; and b) whether 2006 Capital Account Regulations on foreign purchases of Chinese real estate were effective in reducing the level and volatility of prices in the housing market. The results show that hot money magnified the impacts of capital flows on housing prices during upward surges in housing prices. Quantile regression provides quantitative evidence that the more volatile the housing market was, the larger the impact short-term capital flows had on accentuating such volatility. Furthermore, the 2006 CAR continued to have a strong impact on reducing volatility in the Chinese housing market during the period under study.Item Economic imperialism on the global frontier: William Henry Jackson’s photographs for the World’s Transportation Commission, 1894-1897(2023) Monroe, Casey Cameron; Sichel, KimThis dissertation investigates William Henry Jackson’s photographs for an international scouting and fact-finding mission, the World’s Transportation Commission, and the multivalent meaning the images possessed for period patrons and audiences in four contexts. I argue that Jackson visually constructed a homogenous global frontier of economic imperialism that channeled and advanced burgeoning expansionist ideologies in American cultural and political realms during the 1890s. Organized under the auspices of the Field Columbian Museum, the World’s Transportation Commission consisted of five members, including Jackson, who traveled the world between October 1894 and March 1896 seeking information and artifacts regarding railroad history for display at the museum. The Commission also received funding from five major American railroad tycoons, as well as from Harper’s Weekly, which published forty-five articles between February 1895 and August 1897 that featured 372 Jackson photographs. After returning, Jackson presented these pictures as colored lantern slides in a stereopticon lecture series in Colorado throughout spring 1897. Each chapter of this dissertation focuses on one of the four patrons and contexts for which Jackson intended his images and in which they were seen. Chapter One investigates the intended function of these images as didactic objects within a public context for the Field Columbian Museum. The second chapter positions Jackson’s work for five industrialist patrons as an imperial scouting report that studied existing colonial railway systems as models for possible future deployment of corporate interventions throughout Latin America. Chapter Three analyzes the popular cultural dissemination of Jackson’s photographs in Harpers Weekly and the complicated intersections between photographer and editors working to captivate armchair tourists while forwarding notions of ostensible American moral superiority and global hegemony. Chapter Four examines Jackson’s stereopticon lecture tour and his presentation of a hand-colored spectacle within the context of personal entrepreneurial gain. In this final, unmediated venue, Jackson shifted his photographic focus towards a seemingly candid, snapshot approach. My analysis of these four contexts and applications demonstrate how Jackson pictorially destroyed existing worlds of indigenous customs and perspectives, and replaced them with a new, unified vision of an international commercial frontier ripe for exploitation.Item Louis Douglas and Jonny spielt auf: performing Blackness in interwar Germany(2018) Edwards, Paul Johnson; Mizruchi, Susan; Zatlin, JonathanThis dissertation, “Louis Douglas and Jonny spielt auf: Performing Blackness in Interwar Germany,” traces the reception of traveling and expatriate Black American performers in Germany during the interwar period and the cultural productions made by Germans in response to this interaction with the New Negro Renaissance. The performances of Black Americans challenged German views of the European colonizer and the colonized Other. Blackness played an important role in altering conceptions of race and culture during one of the greatest transitions in modern Germany, framed by the extraordinarily open and heterogeneous aesthetic of the Weimar era on one end and the harsh racial stratification of the Nazi regime on the other. Black arts provided a deeply decentering experience, forcing Germans to reassess their conceptions of Black people. Chapter One offers a theory of Black performance that explores how blackface minstrelsy became the referent for Black performance in the twentieth century. Chapter Two examines satirical magazines which introduced working and middle class Germans to Black people in the period between the German Empire and the Weimar Republic. Chapter Three reveals how the first Black American traveling revue, The Chocolate Kiddies, altered German conceptions of Black identity through performances that highlighted the importance of the Great Migration and the performance culture of Harlem. Chapter Four introduces Louis Douglas, a Black American performer who helped to bring Josephine Baker to Europe, and created a revue designed to present Black Americans to French and German audiences. Chapter Five explores how Louis Douglas developed a persona of the modern Black dancer in Germany following Baker’s return to France. Chapter Six examines Ernst Krenek’s blackface “jazz opera” Jonny spielt auf as an exemplary German appropriation of the Black American male body showing how Krenek’s opera created a transnational discourse on the modern Black American man.Item Establishing optimized histology focused methods to study lung cancer using limited biospecimens(2023) Green, Emily Jordan; Mazzilli, SarahLung cancer is the leading cause of cancer deaths worldwide due to the late stage of diagnosis as most patients do not present symptoms until late-stage disease. The two most common forms of non-small cell lung cancer are adenocarcinoma followed by squamous cell carcinoma, which differ in location, appearance and molecular phenotypes and require different approaches for treatment. Prior to the development of invasive lung cancer, premalignant lesions, or regions of abnormal cellular architecture, are often present in the lung. Understanding the pathologic heterogeneity and cellular and molecular alterations in premalignant lesions that precede or are adjacent to invasive carcinomas may help identify the earliest changes in lung carcinogenesis that could be used to identify biomarkers of progression and targets for intervention. Previous work by our group profiling endobronchial biopsies by bulk mRNA sequencing identified gene expression alterations associated with high grade squamous premalignant lesion histology and progression towards advanced histology. Molecular profiling combined with careful pathologic assessment of premalignant lesions are important steps in uncovering the biological processes that are dysregulated in premalignant lesions that progress; however, lung tissue is often limited and fixed. Biopsies of lung tissue, obtained using forceps or needles, are an important diagnostic and prognostic clinical tool although, only tiny amounts of tissue may be left for research. As a result, it is important to work closely with pathologists to review clinical pathology samples and optimize methodologies to use the limited biospecimens available to study these early changes associated with the development of lung cancer. My thesis work focused on the detailed pathologic annotation of lung premalignant lesion biopsies and whole tumor samples and the development of methodologies to profile these small biospecimens to advance lung cancer interception research. Lung squamous cell carcinoma is thought to originate from bronchial premalignant lesions that progress through a series of histological grades to dysplasia (mild, moderate, and severe), carcinoma in situ, and invasive carcinoma. Endobronchial biopsies of these premalignant lesions have heterogeneous pathologic features, and it is not known which features are associated with progression to cancer. In Aim 1 of my thesis, in collaboration with thoracic pathologists, whole slide biopsy images were annotated to identify the histologic grades of surface epithelium, including the presence of angiogenic squamous dysplasia, and stromal features such as the presence of a fibrotic basal membrane under the epithelium. Analyzing these annotations across 284 biopsies identified a significant association between former smokers and the presence of a fibrotic basal membrane. Additionally, we found that when exposed to asbestos, approximately two thirds of patients developed angiogenic dysplasia, while those who were never exposed had a 50% chance of developing it. We also observed a reserve cell dysplasia-like pattern characterized by its nuclear uniformity through all layers, increased nucleus to cytoplasm ratio, hyperchromia, and presence of cilia. This type of dysplasia is not described in the lung to date but is well described in the cervix as a transitional subtype between reserve cell hyperplasia and squamous dysplasia. We quantified the percentage of each histologic grade present in the epithelium of each biopsy and found that there was a weak, but significant, negative correlation between the percentage of normal epithelium and reserve cell dysplasia-like epithelium. The results suggest that reserve cell dysplasia in the lung may be worthy of more study, as it is found to be only inversely correlated with normal epithelium. More studies must be done to elucidate its true role in the premalignant to malignant process. To complement the pathologic analysis of endobronchial biopsies in Aim 2, we examined 31 lung cancer resection cases where premalignant lesions were present in the tumor margins. Our goal was to profile the RNA and DNA of multiple regions within each case to identify molecular alterations associated with the transition from premalignant to tumor tissue. The 31 cases were stained with H&E and mIHC panels using markers corresponding to epithelial, immune, and stromal cell types. We annotated the H&E stains alone and together with the mIHC stains and found that we annotated significantly more unique regions when considering both data modalities. We captured the annotated regions using an optimized laser capture microdissection (LCM) protocol. The goal of Aim 3 was to first optimize the LCM and isolation protocols for limited FFPE lung samples. We accomplished this using a smaller group of eight samples, of which six were LCM’d, by comparing different DNA and RNA isolation kits to select the kit that offered the highest quality and greatest amount of isolated DNA and RNA. The LCM tissue from the 31 cases is currently undergoing RNA and DNA sequencing and we hope the data analysis will identify unique tissue microenvironments associated with premalignant lesion progression. These findings contribute to existing lung cancer and premalignancy research, which, as a field, aims to identify progressing lesions and treat patients at earlier stages to decrease mortality. My thesis work has focused on characterizing the pathologic features of lung squamous premalignant lung lesions and their associations with premalignant progression to cancer and other clinical covariates such as smoking status and carcinogenic exposures. To fully understand these pathologic features, I have developed methods to isolate high quality RNA and DNA from these limited biospecimens to allow for the identification of the molecular alterations underpinning the pathological changes.Item Effects of interprofessional education on patient satisfaction(2023) Wong, Natalie; Wisco, Johnathan J.; Weinstein, John R.Interprofessional education (IPE) is a well-known topic in the healthcare field as patient care and medicine becomes increasingly more complex especially in specific populations. IPE can take varying forms and can be implemented in healthcare didactic schooling, student run clinics, or in continuing education. The benefits of interprofessional education and collaboration are well known, including improving teamwork and mutual respect, awareness of the roles and responsibilities of the healthcare team, and patient outcomes. Though IPE have been extensively studied, there still exists gaps in research especially in terms of patient populations, types of IPE curriculum or training, and types of patient outcomes. The proposed project aims to assess if a single day, interprofessional education specified training workshop conducted to inpatient internal medicine healthcare teams can improve patient satisfaction. This study can provide additional data for the benefit of implementing IPE in patient care settings.Item Biofluid identification in mock sexual assault samples using a semi-automated, extraction-free microRNA gene expression profiling method(2023) Yang, Xiaomeng; Brodeur, Amy N.Biofluid identification plays a pivotal role in forensic case investigation, as it assists in crime scene reconstruction and provides guidance for subsequent analysis. Current forensic biofluid detection techniques, such as alternate light sources, catalytic color tests, and lateral flow immunochromatographic assays, exhibit limitations in terms of sensitivity and specificity, and most can only detect one biofluid at a time. Developing a multiplex and confirmatory assay will significantly benefit forensic biofluid identification, with nucleic acid-based assays emerging as the most promising candidates. Among various nucleic acids, microRNAs boast biofluid specificity and exceptional stability, rendering them an optimal choice for biofluid identification assay and the focal point of this study. In this study, we investigated a semi-automated, extraction-free microRNA gene expression profiling method developed by HTG Molecular Diagnostics, Inc., namely HTG EdgeSeq microRNA Whole Transcriptome Assay, utilizing seven biofluid types frequently encountered in sexual assault cases, including peripheral blood, menstrual blood, saliva, vaginal fluid, and semen with varying sperm counts. The research focused on three aspects: the assay’s compatibility with whole blood samples and dried biofluid swab samples, its ability to identify and classify different biofluid types based on their microRNA expression patterns, and its potential to differentiate biofluids within mixtures. Our results demonstrate that HTG EdgeSeq microRNA Whole Transcriptome Assay effectively identified several differentially expressed microRNAs in each biofluid. Examples that align with the existing literature include miR-451a and 486-5p for all kinds of blood, miR-185-5p for peripheral blood, and miR-888-5p and 891a-5p for semen. Previously unreported microRNAs with biofluid-specific expressions were also discovered, such as miR-4306 for peripheral blood and miR-184 for saliva. The scatter plots and heat maps generated from experimental data exhibit distinctive microRNA expression profiles for different biofluid types, potentially enabling their identification and classification. Furthermore, the analysis of mixtures reveals that differentially expressed microRNAs in mixtures corresponded to those detected in the single-source biofluids, signifying the assay’s capacity to resolve biofluid mixtures. The assay also yields optimal results for whole blood and dried biofluid swab samples, displaying its compatibility with sample types frequently found in forensic casework. The outcomes from this study suggest the potential of HTG EdgeSeq microRNA Whole Transcriptome Assay to be employed in forensic biofluid identification, as it demonstrates high reproducibility, multiplex capacities, and compatibility with common forensic casework samples. Future studies encompassing a broader spectrum of biofluid types, and a greater number of individuals are required to validate the findings in this study and optimize the workflow for applying the assay in forensic laboratories.Item Assessing reactive attachment disorder screening tools in foster care children: a comparative study(2023) Wiseman, Aurora; Augustyn, Marilyn C.Although foster care was created as a safeguard for children in difficult circumstances, it is often associated with negative impacts on their relationships, development, and overall mental health. Those children placed into foster care often have experienced trauma early in life, putting their pivotal early attachment at risk and thus increasing their risk of developing attachment disorders such as reactive attachment disorder (RAD). For many years, researchers have repurposed mental health assessment tools for application in screening for RAD. Recently, researchers have begun to develop and trial tools using the RAD diagnostic criteria to screen for RAD. However, there is a need for more research on applying these screening techniques within the foster care population. This thesis aims to evaluate and compare screening instruments for Reactive Attachment Disorder (RAD) in young foster care children to improve early identification and reliability. This proposal adopts a cross-section design to investigate and evaluate the use of three RAD specific screening instruments in young foster care children: the Reactive Attachment Disorder Checklist (RAD-C), Reactive Attachment Disorder Questionnaire (RAD-Q), and Reactive Attachment Disorder Screening Instrument (RADSI). The study reinforces the conclusion that targeted screening tools designed explicitly for RAD can lead to more accurate and early identification of symptoms in this population. Consequently, the improved ability to identify RAD in foster care children can lead to earlier intervention and support, ultimately aiming to improve long-term outcomes.Item Screening for undiagnosed atrial fibrillation to prevent stroke(2023) Varley-Barrett, Dorrie; DiPetrillo, Melissa D.; Weinstein, John R.BACKGROUND: AF is a growing epidemic in the United States that will continue to worsen as risk factors become more prevalent in the population. The arrhythmia often persists asymptomatically before presenting as a stroke or when the disease has progressed to cause permanent cardiac restructuring. The gold standard for diagnosis is ECG. The current treatment consists of rate control, rate control, and stroke prevention with anticoagulation. LITERATURE REVIEW: Recent studies have shown that screening for AF does result in an increase in AF diagnosis. A current gap in literature remains regarding if that increase in AF diagnosis leads to a stroke reduction in the screened population. PROPOSED PROJECT: The proposed project is a randomized control trial that will compare AF diagnosis in a control group to a group that is screened for AF using a 30-day cardiac monitor. The statistical analysis will reveal if there is a reduction in stroke and other cardiac sequelae in the screened group compared to the control group. CONCLUSION/SIGNIFICANCE: Should the study reveal that screening for AF in an at-risk population reduces the risk of stroke, it could assist the USTF in addressing the gap in literature required to either recommend for or against AF screening in the United States.Item Principal component analysis of gasoline DART-MS data for forensic source attribution(2023) Vanderfeen, Allison M.; Hall, Adam B.Rapid and reliable techniques are necessary for the analysis of accelerants, including gasoline, from fire debris evidence in forensic arson investigations. Gasoline additives can be used as chemical attribute signatures (CAS) to distinguish between source locations due to the variation in additives used. Source attribution using CAS is needed in forensic chemistry, as the determination of a single gasoline source could be a potential investigation tool for law enforcement and other agencies conducting arson investigation. Direct analysis in real time-mass spectrometry (DART-MS) has had increasing popularity in the field of forensic chemistry for chemical analysis, and it has been applied to fire debris analysis. DART-MS has great capacity for gasoline source attribution due to its ionization technique and inclusion of higher molecular weight ions, which correspond to the CAS in gasoline. To test the hypothesis of gasoline source attribution, 21 gasoline samples were collected across Massachusetts, New Hampshire, and Connecticut. DART-MS data were generated for each sample of gasoline in replicates of 10. The data were grouped based on geographical location and evaluated by Principal Component Analysis (PCA). PCA was used to evaluate the similarities and differences in gasoline DART-MS data by generating and classifying the gasoline sample groups formed. Leave-one-out cross-validation (LOOCV) was performed on each geographical group after PCA. LOOCV was used as the validation technique to determine the validity of the model and asses its capability at classifying unknown gasoline samples. DART-MS data across geographical groups was found to have varying levels of similarity and difference through visual inspection of the mass spectra. PCA showed distinct groupings of individual gasoline samples across all tested geographical groups, with 3 out of 6 geographical groups showing no overlap between gasoline sample classifications. Two groups showed minimal overlapping, while 1 group had overlapping between multiple gasoline sample classifications. Three groups had a LOOCV of 100% with no misclassifications. The other LOOCV were 98%, 96.67%, and 85%. The PCA and comparison of DART-MS data provides evidence of successful differentiation between gasoline samples of the same brand across Massachusetts, New Hampshire, and Connecticut. This research aims to provide an overview and understanding of chemometrics and DART-MS and how these techniques may be applied for forensic source attribution purposes.Item The relationship between patient BMI and the choice of total hip arthroplasty approach(2023) Torrence, Corey Alexandra; Weinstein, John; Smith, MichaelMany people across the world suffer from joint pain with age. The degeneration of the space between bones, osteoarthritis, is an extremely common disease, known to affect around 7% of the global population. Two of the most common risk factors to the development of osteoarthritis is body weight and inactivity. These factors are usually the first target of lifestyle changes that are recommended when a patient presents to an orthopedic clinic with joint pain, specifically knee or hip. This is because the weight of the body puts pressure on the joints and leads to breakdown of the joint spaces, causing arthritis to develop and progress. Many treatment options are available for people that suffer from joint pain -- medications, injections, physical therapy, and lifestyle changes. However, the gold standard treatment option for the gradual degeneration of joint spaces is a total or partial joint replacement depending on the severity of the disease and how compromised the patient’s day to day life is at that time. Many orthopedic surgeons prefer to exhaust more conservative treatment options prior to approving surgery, however, many patients eventually require a joint replacement due to disease relentlessness. There are two main approaches to hip replacement surgeries, anterior and posterior approach. The posterior approach has been used in practice for the longest amount of time and was the initial surgical option. However, more recently, the anterior approach has been introduced and is on the rise due to several factors that make it favorable to many providers and patients over the long-standing posterior approach. Given that many patients who eventually require joint replacement are overweight or lead a lifestyle that is very sedentary, this study will investigate whether a patient’s body mass index should influence whether the anterior approach should be used based on patient outcomes and success from the two approaches.Item Characterization of blood and vaginal fluid using a microRNA expression profiling method(2023) Tan Palanca, Isabel Luisa N.; Cotton, Robin W.MicroRNAs (miRNAs) are short non-coding sequences that function in maintaining tissue and cell specificity. These characteristics have made them ideal candidiates for body fluid identification. This study aims to determine if miRNA expression profiles can be used to differentiate vaginal fluid samples collected at different time points within a single menstrual cycle, as well as miRNA markers that can be used to differentiate menstrual blood from peripheral blood. The HTG EdgeSeq® workflow was used to prepare and analyze the samples. The HTG Reveal software was used to analyze the expression profiles of these samples by conducting pairwise comparisons. The top differentially expressed probes based on “rawP” values were assessed for observable trends in their fold changes. Potential miRNA markers for vaginal fluid, peripheral blood, and menstrual blood in this study and those from existing literature were identified. Week 3 appears to be the most different among the vaginal fluid only samples within the menstrual cycle. Minimal differences were observed between the samples of Weeks 1 and 2, thus the identified differentially expressed probes could not be reliably used to differentiate all timepoints in the menstrual cycle. MiR-200b-3p is the only probe out of four possible menstrual blood markers with supporting evidence from the data collected in this study and in literature. Several other miRNAs (miR-106a, miR-144-3p, miR-16-5p, miR-25-3p, miR-451a, miR-486-5p, and miR-93-5p) show potential as blood markers without distinguishing between peripheral and menstrual blood. Possible miRNA markers for vaginal fluid in general were also determined: miR-124-3p, miR-128-1-5, mir-147b, miR-193b-5p, miR-5585-3p, and miR-612.Item Identification of D-dimer in postmortem blood(2023) Tsai, Tai-Hua; Brodeur, Amy N.D-dimer, a type of fibrin degradation product, has been reported to be elevated in postmortem and menstrual blood as well as in peripheral blood of individuals with certain medical conditions. Clinically, D-dimer is used as a target for identifying fibrinolysis activity. In the forensic field, the presence of D-dimer has shown a high potential as a screening tool for distinguishing postmortem blood from antemortem blood at a crime scene. This research explores four methods for detecting D-dimer in liquid and dried human blood – UV-Vis spectroscopy, a rapid latex agglutination assay, a latex-enhanced immunoturbidimetric assay, and a lateral flow immunochromatographic assay – and evaluates the feasibility of targeting D-dimer as an indicator for postmortem blood. Of the four methods used in this research for detecting D-dimer in postmortem blood, the SERATEC® PMB immunochromatographic test showed the most promising results with a positive reaction rate of 97%. Postmortem and menstrual blood samples both showed elevated D-dimer levels compared to antemortem samples, however, to increase the sensitivity of the test, a reading time extended to 60 minutes is recommended for suspected low-concentration samples. Additionally, the approximate concentration of D-dimer as determined by the latex agglutination assays had no correlation with the postmortem interval of the samples. In conclusion, while D-dimer shows potential for distinguishing postmortem blood, factors such as medical history, age, and the possibility of menstrual blood must be considered when interpreting results.Item Alterations in white matter of the brain after spinal cord injury(2023) Tran, Diana Ngo; Offner, Gwynneth; Linnman, ClasThis study investigated potential alterations in brain white matter after spinal cord injury (SCI). Individuals with SCI underwent magnetic resonance diffusion tensor imaging (DTI) and alterations were assessed based on dynamic changes in fractional anisotropy (FA) and apparent diffusion coefficient (ADC) parameters. Three contrast analyses compared FA and ADC values between person with SCI and healthy controls for the Boston cohort, the Denver cohort, and the grouped cohort. Persons with SCI were found to have lower FA and higher ADC values than health controls across all cohorts. These results are consistent with established correlations between DTI values and alteration of brain white matter in other chronic neurodegenerative conditions. This suggests that DTI is a useful tool for measuring white matter changes in the brain following SCI.Item Alteration of the gut microbiome by scutellaria-coptis herb couple and metformin in type 2 diabetes(2023) Tran, Kelley; Weber, H. Christian; Weinstein, John R.There is a rising global prevalence of type 2 diabetes (T2D), which poses both health and economic burdens. Effective research on T2D and clinical interventions can decrease the impact of these burdens and fill knowledge gaps in their efficacy, safety, and long-term outcomes. This comprehensive literature-based review examines the role of the gut microbiome in T2D and treatments, such as metformin and scutellaria radix-coptidis rhizoma (SC) herb couple, for gut microbiome (GM) modulation and improvement in T2D. For the purposes of this thesis, the GM is defined as a healthy nondiabetic GM, whereas dysbiosis, a deviation from a healthy GM maybe associated with the pathogenesis of T2D in terms of glucose metabolism, insulin sensitivity and inflammatory pathways and dysbiosis has been observed in individuals with a diagnosis of T2D. Microbial metabolites, such as short chain fatty acids and bile acids, and inflammatory processes have been associated with diabetes-related outcomes. Metformin, a traditional first line antidiabetic agent, as well as the traditional Chinese medicine herb couple, SC, modulate the composition of the GM in alleviating T2D. Based on the current body of knowledge, we propose to further investigate the effect of metformin and SC on the GM in T2D alleviation and measure the composition of the GM before and after an interventional clinical trial period. Investigating the effects of these study drugs and their relation to the GM may provide new insights on the pathogenesis and management of T2D.