31 research outputs found
Micro-computed tomographic evaluation of dentinal defects after root canal preparation with hyflex edm and vortex blue rotary systems
To evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography. Mandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar?s test at a significance level of 5%. HyFlex EDM has shown greater increase in post instrumentation dentinal defects. Both rotary systems exhibited increased dentinal defects formation at coronal, middle regions which is statistically significant (P=0.042) when compared to apical region. HyFlex EDM has shown greater increase in post instrumentation dentinal defects followed by Vortex Blue rotary system and hand instrumentation resulted minimal defects
High Fidelity System Simulation of Multiple Components in Support of the UEET Program
The High Fidelity System Simulation effort has addressed various important objectives to enable additional capability within the NPSS framework. The scope emphasized High Pressure Turbine and High Pressure Compressor components. Initial effort was directed at developing and validating intermediate fidelity NPSS model using PD geometry and extended to high-fidelity NPSS model by overlaying detailed geometry to validate CFD against rig data. Both "feedforward" and feedback" approaches of analysis zooming was employed to enable system simulation capability in NPSS. These approaches have certain benefits and applicability in terms of specific applications "feedback" zooming allows the flow-up of information from high-fidelity analysis to be used to update the NPSS model results by forcing the NPSS solver to converge to high-fidelity analysis predictions. This apporach is effective in improving the accuracy of the NPSS model; however, it can only be used in circumstances where there is a clear physics-based strategy to flow up the high-fidelity analysis results to update the NPSS system model. "Feed-forward" zooming approach is more broadly useful in terms of enabling detailed analysis at early stages of design for a specified set of critical operating points and using these analysis results to drive design decisions early in the development process
Probabilistic Integrity and Risk Assessment of Turbine Engines, Phase II
15-G-016This grant supported the efforts of the Federal Aviation Administration (FAA) to develop an enhanced life management process, based on probabilistic damage tolerance principles, to address the threat of material or manufacturing anomalies in high-energy rotating components of aircraft engines. Major research products included formal verification and validation of Design Assessment of Reliability With INspection (DARWIN\uae) stress-intensity factor solutions; enhanced DARWIN capabilities for manual and automatic fracture mechanics modeling, probabilistic methods, and fleet risk methods. Substantial improvements in the speed and robustness of DARWIN for large finite element (FE) models; streamlined methods for deterministic life calculations; a DARWIN Python module to facilitate scripting of multiple DARWIN runs; options to specify or limit optional features or default values available in DARWIN; new advanced visualization capabilities enabling users to define and manipulate regions within three-dimensional FE models; multiple new versions of the DARWIN computer code for technology transfer to industry and the FAA, and a large DARWIN training workshop are also included. The efforts facilitate implementation of official advisory material for axial blade slots, titanium hard alpha anomalies, and circular holes, while also developing improved analysis methods for other applications of deterministic and probabilistic damage tolerance to engine safety
Pleomorphic presentations of IgA nephropathy - postrenal transplantation
IgA nephropathy (IgAN) is a common cause of glomerulonephritis and end-stage renal disease. The recurrence of IgAN postrenal transplant is well documented. IgA recurrence posttransplant manifests as recurrent IgAN, de novo IgAN, and crescentic IgAN. Three cases are described in this article, representing the above-mentioned presentations of IgAN. The first case represents the manifestation of crescentic IgAN in a renal transplant recipient. The patient presented with severe graft dysfunction requiring hemodialysis. Inspite of aggressive immunosuppression and plasmapheresis, the graft kidney could not be salvaged. The second case represents recurrent IgAN. The patient was initiated on antiproteinuric measures and has maintained a stable graft function. The third case presented with de novo IgAN and acute antibody-mediated rejection (AMR). This patient was treated with immunosuppressants and plasmapheresis as per AMR treatment guidelines, following which his graft function improved
Understanding COVID-19 vaccine hesitancy in Meghalaya, India: Multiple correspondence and agglomerative hierarchical cluster analyses
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Table A. Vaccine hesitancy questionnaire Table B. Eigen value and percentage of variance explained by each dimension in the multiple correspondence analysis Fig A. Variable coordinates of multiple correspondence analysis (Dimensions 1 and 3) Fig B. Variable coordinates of multiple correspondence analysis (Dimensions 1 and 4) Fig C. Variable coordinates of multiple correspondence analysis (Dimensions 1 and 5) Fig D. Variable coordinates of multiple correspondence analysis (Dimensions 2 and 3) Fig E. Variable coordinates of multiple correspondence analysis (Dimensions 2 and 4) Fig F. Variable coordinates of multiple correspondence analysis (Dimensions 2 and 5) Fig G. Variable coordinates of multiple correspondence analysis (Dimensions 3 and 4) Fig H. Variable coordinates of multiple correspondence analysis (Dimensions 3 and 5) Fig I. Variable coordinates of multiple correspondence analysis (Dimensions 4 and 5) Table C. Demographic and socioeconomic characteristics of survey respondents in each cluster (DOCX)</p
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Meghalaya, a state in the northeastern region of India, had a markedly low vaccine uptake compared to the other states in the country when COVID-19 vaccines were being rolled out in 2021. This study aimed to characterize the distinct vaccine-hesitant subpopulations in healthcare and community settings in Meghalaya state in the early days of the vaccination program. We used data from a cross-sectional survey that was administered to 200 healthcare workers (HCWs) and 200 community members, who were a priori identified as ‘vaccine-eligible’ and ‘vaccine-hesitant,’ in Shillong city, Meghalaya, in May 2021. The questionnaire collected information on participants’ sociodemographic characteristics, COVID-19 history, and presence of medical comorbidities. Participants were also asked to provide a dichotomous answer to a set of 19 questions, probing the reasons for their hesitancy towards COVID-19 vaccines. A multiple correspondence analysis, followed by an agglomerative hierarchical cluster analysis, was performed to identify the distinct clusters of vaccine-hesitant participants. We identified seven clusters: indecisive HCWs (n = 71), HCWs skeptical of COVID-19 and COVID-19 vaccines (n = 128), highly educated male tribal/clan leaders concerned about infertility and future pregnancies (n = 14), less educated adults influenced by leaders and family (n = 47), older adults worried about vaccine safety (n = 76), middle-aged adults without young children (n = 56), and highly educated ethnic/religious minorities with misinformation (n = 8). Across all the clusters, perceived logistical challenges associated with receiving the vaccine was identified as a common factor contributing to vaccine hesitancy. Our study findings provide valuable insights for local and state health authorities to effectively target distinct subgroups of vaccine-hesitant populations with tailored health messaging, and also call for a comprehensive approach to address the common drivers of vaccine hesitancy in communities with low vaccination rates.</div
Coordinates of all the variables on the first two dimensions of multiple correspondence analysis (MCA).
Coordinates of all the variables on the first two dimensions of multiple correspondence analysis (MCA).</p