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NCUR 2021 Proceedings A Diffusion Approach for Plasma Synthesis of Superhard Tantalum Borides Physics/Astronomy - Time: Tue 3:30pm-4:30pm - Session Number: 745 Aaditya Rau, Dr. Aaron Catledge, Department of Physics, The University of Alabama at Birmingham, 1720 2nd Ave S, Birmingham, Alabama 35294 Aaditya Rau Tantalum borides are a set of refractory metal compounds that have become of interest due to their desirable mechanical, thermal, and electrical properties. While these compounds have been previously synthesized in a variety of methods, key issues related to sample size, sample integrity, and implementation feasibility limit their use. In this study, a microwave plasma chemical vapor deposition (MPCVD) reactor was used to diffuse boron into tantalum substrates using a feedgas mixture of hydrogen and diborane. Specifically, the role of substrate temperature and substrate bias in influencing the chemical composition and mechanical properties of the borided tantalum was investigated. X-ray diffraction shows that high substrate temperature is favorable for TaB2 formation, with samples made at great than 775°C having a mean surface hardness of 40 GPa along with increased strain in the tantalum body-centered cubic lattice. Once the strained tantalum becomes locally supersaturated with boron, TaB and TaB2 precipitate. The combination of precipitation hardening as well as solid solution hardening may help explain the measured superhardness, as measured by nanoindentation. Application of a negative bias voltage to the substrate during the CVD process was not found to further increase the hardness, and in some cases decreased the measured hardness significantly, possibly due to etching effects from increased ion bombardment. These results show that MPCVD is a viable method for synthesis of superhard borides based on plasma-assisted diffusion. Tantalum borides are a set of refractory metal compounds that have become of interest due to their desirable mechanical, thermal, and electrical properties. While these compounds have been previously synthesized in a variety of methods, key issues related to sample size, sample integrity, and implementation feasibility limit their use. In this study, a microwave plasma chemical vapor deposition (MPCVD) reactor was used to diffuse boron into tantalum substrates using a feedgas mixture of hydrogen and diborane. Specifically, the role of substrate temperature and substrate bias in influencing the chemical composition and mechanical properties of the borided tantalum was investigated. X-ray diffraction shows that high substrate temperature is favorable for TaB2 formation, with samples made at great than 775°C having a mean surface hardness of 40 GPa along with increased strain in the tantalum body-centered cubic lattice. Once the strained tantalum becomes locally supersaturated with boron, TaB and TaB2 precipitate. The combination of precipitation hardening as well as solid solution hardening may help explain the measured superhardness, as measured by nanoindentation. Application of a negative bias voltage to the substrate during the CVD process was not found to further increase the hardness, and in some cases decreased the measured hardness significantly, possibly due to etching effects from increased ion bombardment. These results show that MPCVD is a viable method for synthesis of superhard borides based on plasma-assisted diffusion. Comparison of Operative Techniques for Closed Reduction of Supracondylar Humerus Fractures in Children Health & Human Development - Time: Tue 3:30pm-4:30pm - Session Number: 5097 Chimelie Chibututu, R. Jay Lee M.D., Department of Orthopaedic Surgery at Johns Hopkins School of Medicine (department of my faculty mentor), Johns Hopkins University, 480 Wallenberg Crescent, Mississauga, Ontario, Canada, L5B 3M1 Chimelie Chibututu Background: Fractures of the supracondylar are among the most common fractures in children. Despite their ubiquity there is no agreement on the ideal technique for surgical reduction. While some believe the cross-pins technique provides greater stability and minimizes loss of reduction, it has been associated with higher risk of post-operative neuropathy. As a result, others are in favor the lateral-entry technique – which avoids the ulnar nerve but has been associated with lower stability. Past work has indicated that if differences in outcomes between the two techniques exist, they may be related to degree of elbow flexion during pin placement as well as the greater stability of the cross-pins construct. Thus, the goal of this review is to compare prone position cross-pins constructs, supine position cross-pins constructs, and mini-medial cross-pins constructs to lateral-entry constructs in terms of loss of reduction, and incidence of post-operative neuropathy. Methods: A review of the literature from 2000 – October 2020 was performed using Science, PubMed, Google Scholar and the Journal of Pediatric Orthopedics using keywords “lateral-entry”, “supracondylar humerus fracture”, “closed reduction” and “ulnar nerve injury.” Randomized clinical trials were given priority but cohort studies were also included. We will perform a statistical analysis of the rates of loss of reduction and post-operative neuropathy for each technique. Results: Given the recent success of prone position cross-pins constructs we predict that the incidence of post-operative neuropathy will be lower in this group than in the supine position or lateral-entry groups. Conclusions: Modifications to the current techniques for fracture fixation may result in lower incidence of ulnar nerve damage while still retaining optimal stability. Background: Fractures of the supracondylar are among the most common fractures in children. Despite their ubiquity there is no agreement on the ideal technique for surgical reduction. While some believe the cross-pins technique provides greater stability and minimizes loss of reduction, it has been associated with higher risk of post-operative neuropathy. As a result, others are in favor the lateral-entry technique – which avoids the ulnar nerve but has been associated with lower stability. Past work has indicated that if differences in outcomes between the two techniques exist, they may be related to degree of elbow flexion during pin placement as well as the greater stability of the cross-pins construct. Thus, the goal of this review is to compare prone position cross-pins constructs, supine position cross-pins constructs, and mini-medial cross-pins constructs to lateral-entry constructs in terms of loss of reduction, and incidence of post-operative neuropathy. Methods: A review of the literature from 2000 – October 2020 was performed using Science, PubMed, Google Scholar and the Journal of Pediatric Orthopedics using keywords “lateral-entry”, “supracondylar humerus fracture”, “closed reduction” and “ulnar nerve injury.” Randomized clinical trials were given priority but cohort studies were also included. We will perform a statistical analysis of the rates of loss of reduction and post-operative neuropathy for each technique. Results: Given the recent success of prone position cross-pins constructs we predict that the incidence of post-operative neuropathy will be lower in this group than in the supine position or lateral-entry groups. Conclusions: Modifications to the current techniques for fracture fixation may result in lower incidence of ulnar nerve damage while still retaining optimal stability. Electronic Nicotine Delivery System Induced Inflammatory Responses and Related Risk of COVID-19: A Literature Review Biology - Time: Mon 4:30pm-5:30pm - Session Number: 3129 Kriti Bomb, Dr. Kenneth Witwer, and Dr. Zhaohao Liao, Witwer Lab, Johns Hopkins University, 733 N Broadway, Baltimore, MD 21205 Kriti Bomb Electronic nicotine delivery systems (ENDS) have recently gained popularity as “healthy” alternatives to smoking cigarettes. However, the mechanism of use and the chemicals in ENDS are severely damaging, especially in adolescents and immunocompromised persons. Most ENDS devices contain e-liquid cartridges that are heated to produce aerosolized vapors, and inhaling these vapors can result in inflammation, pulmonary cytotoxicity, and vaping-associated lung injury. Increased ENDS use is a pandemic of its own, with limited research into its biological consequences, especially in younger users. Here, we examine why ENDS users might be at greater risk for developing COVID-19 complications, primarily focusing on inflammatory responses induced by aerosol inhalation. This literature review was limited to studies of ENDS users, excluding nicotine/tobacco products such as cigarettes. Only SARS-CoV-2 studies were considered, excluding other coronavirus infections. After thorough assessment of around n=50 articles with ENDS and COVID-19 keywords, n=10 papers satisfied all consideration criteria. Patients with severe cases of COVID-19 may present with inflammation-related complications such as acute respiratory distress syndrome (ARDS) and acute respiratory pneumonia, and aerosol vapors can aggravate such inflammation. If an ENDS user is exposed to SARS-CoV-2, inflammasome complexes may be activated. Release of extracellular vesicles (EVs) from exposed pulmonary epithelium or platelets may initiate an inflammatory cascade or trigger a cytokine storm. Further, in ENDS users, there is increased expression of the angiotensin-converting enzyme-2 (ACE-2) receptor in the lungs, which is also upregulated by smoking and acts as the viral receptor for SARS-CoV-2.