1,846 research outputs found

    Development of Prediction Method for Dimensional Stability of 3D-Printed Objects

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    Fused deposition modeling (FDM), as one of the additive manufacturing processes, is known for strong layer adhesion suitable for prototypes and end-use items. This study used a multiple regression model and statistical analysis to explore the dimensional accuracy of FDM objects. Factors such as inclination angle, layer thickness, support space, and raster angle were examined. Machine learning models (Gaussian process regression (GPR), support vector machines (SVM), and artificial neural network (ANN)) predicted dimensions using 81 datapoints. The mean squared dimensional error (MSDE) between the measured and designed surface profiles was selected as an output for the dimensional accuracy. Support spacing, layer thickness, and raster angle were determined to be statistically significant, and all factors were confirmed as significant predictors. The coefficients of determination for multiple linear regression, GPR, SVM, and ANN models were 76%, 98%, 93%, and 99%, respectively. The mean absolute errors (MAEs)—errors between the measured and the predicted MSDEs—were 0.020 mm and 0.034 mm, respectively, for GPR and SVM models. The MAEs for ANN models were 0.0055 mm for supporting cases and 2.1468 x 10 -5 mm for non-supporting cases

    Strain-induced delamination of edge-grafted graphite

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    Edge-selectively grafted graphite (EGG) with poly(ether-ketone) was prepared by the Friedel-Crafts acylation in a mild polyphosphoric acid (PPA)-phosphorous pentoxide (P2O5) mixture. The homogeneous reaction dope was coagulated in air moisture at different temperatures. The morphology of expanded EGG was changed from balls, balls/rods and rods with respect to coagulation temperatures of 80, 60, 40 and 25 degrees C, respectively.close1

    Small-cell neuroendocrine carcinoma of the breast

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    A small-cell carcinoma is one of the histologic subtypes of primary neuroendocrine carcinomas of the breast. A small-cell carcinoma is a rare entity of the breast and exhibits similar morphologic features as neuroendocrine tumors of the gastrointestinal tract and lung. We present the imaging and pathologic findings of a primary small-cell neuroendocrine carcinoma of the breast. This is the first report of a primary small-cell carcinoma arising from the breast in Korea

    Prediction of Plaque Progression in Coronary Arteries Based on a Novel Hemodynamic Index Calculated From Virtual Stenosis Method

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    RationalePredicting the sites in coronary arteries that are susceptible to plaque deposition is essential for the development of clinical treatment strategies and prevention. However, to date, no physiological biomarkers for this purpose have been developed. We hypothesized that the possibility of plaque deposition at a specific site in the coronary artery is associated with wall shear stress (WSS) and fractional flow reserve (FFR).Background and ObjectiveWe proposed a new biomarker called the stenosis susceptibility index (SSI) using the FFR and WSS derived using virtual stenosis method. To validate the clinical efficacy of this index, we applied the method to actual pilot clinical cases. This index non-invasively quantifies the vasodilation effects of vascular endothelial cells relative to FFR variation at a specific coronary artery site.Methods and ResultsUsing virtual stenosis method, we computed maximum WSS and FFR according to the variation in stenotic severity at each potential stenotic site and then plotted the variations of maximum WSS (y-axis) and FFR (x-axis). The slope of the graph indicated a site-specific SSI value. Then we determined the most susceptible sites for plaque deposition by comparing SSI values between the potential sites. Applying this method to seven patients revealed 71.4% in per-patient basis analysis 77.8% accuracy in per-vessel basis analysis in percutaneous coronary intervention (PCI) site prediction.ConclusionThe SSI index can be used as a predictive biomarker to identify plaque deposition sites. Patients with relatively smaller SSI values also had a higher tendency for myocardial infarction. In conclusion, sites susceptible to plaque deposition can be identified using the SSI index

    Pre-Pregnancy Body Mass Index Is Associated with Dietary Inflammatory Index and C-Reactive Protein Concentrations during Pregnancy

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    There have been a limited number of studies examining the association between pre-pregnancy body mass index (BMI) and dietary inflammation during pregnancy. Our aim is to examine the association between pre-pregnancy BMI and the Dietary Inflammatory Index (DII)™ and C-reactive protein (CRP) concentrations during pregnancy. The study included 631 pregnant American women from the National Health and Nutrition Examination Survey (NHANES) cross-sectional examinations from 2003 to 2012. Pre-pregnancy BMI was calculated based on self-reported pre-pregnancy weight and measured height. The cut-offs of \u3c18.5 (underweight), 18.5–24.9 (normal), 25.0–29.9 (overweight), and ≥30 kg/m2 (obese) were used to categorize the weight status of pregnant women prior to pregnancy. The DII, a literature-based dietary index to assess the inflammatory properties of diet, was estimated based on a one-day 24-h recall. Multivariable linear and logistic regressions were performed to estimate beta coefficients and the adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) on the association of pre-pregnancy BMI categories with the DII and CRP concentrations during pregnancy. After controlling for variables including: race/ethnicity, family poverty income ratio, education, marital status, month in pregnancy, and smoking status during pregnancy; women who were obese before pregnancy (n = 136) had increased odds for being in the highest tertile of the DII and CRP concentrations compared to women with normal weight (AORs 2.40, 95% CIs 1.01–5.71; AORs 24.84, 95% CIs 6.19–99.67, respectively). These findings suggest that women with pre-pregnancy obesity had greater odds of reporting higher DII and having elevated CRP. In conclusion, high pre-pregnancy BMI was associated with increased odds of pro-inflammatory diet and elevated CRP levels during pregnancy in the USA

    Efficacy and Tolerability of GCSB-5 for Hand Osteoarthritis: A Randomized, Controlled Trial

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    AbstractPurposeThe aim of this study was to investigate the efficacy and tolerability of GCSB-5, a mixture of 6 purified herbal extracts, in treating hand osteoarthritis (OA).MethodsA randomized, double-blind, placebo-controlled trial enrolled 220 patients with hand OA who had baseline a visual analog scale joint pain score of >30 of 100 mm at 3 hospitals between September 2013 and November 2014. After randomization, patients were allocated to receive oral GCSB-5 600 mg or placebo, bid for 12 weeks. The primary end point was the change in the Australian/Canadian OA Hand Index (AUSCAN)-defined pain score at 4 weeks relative to baseline. Secondary end points included the frequency Outcome Measures in Rheumatology–OA Research Society International (OMERACT-OARSI)-defined response at 4, 8, 12, and 16 weeks after randomization.FindingsThe allocated treatment was received by 109 and 106 patients in the GCSB-5 and placebo groups, respectively. At 4 weeks, the median (interquartile range) change in AUSCAN pain score relative to baseline was significantly greater in the GCSB-5 group than in the placebo group (–9.0 [–23.8 to –0.4] vs –2.2 [–16.7 to 6.0]; P = 0.014), with sustained improvement at 8, 12, and 16 weeks (P = 0.039). The GCSB-5 group also had a significantly greater OMERACT-OARSI–defined response rate than did the placebo group at 4 weeks (44.0% vs 30.2%), 8 weeks (51.4% vs 35.9%), 12 weeks (56.9% vs 40.6%), and 16 weeks (50.5% vs 37.7%) (P = 0.0074). The 2 treatments exhibited comparable safety profiles.ImplicationsGCSB-5 was associated with improved symptoms of hand OA, with good tolerability, in these patients. GCSB-5 may be a well-tolerated alternative of, or addition to, the treatment of hand OA. ClinicalTrials.gov identifier: NCT01910116
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