9 research outputs found

    Design Optimization of DR3AM Vapor Polishing Device for ABS 3D-Printed Parts

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    3D printing is an additive manufacturing method that turns digital design into an actual product. A 3D-printed part sometimes requires post-processing to enhance its physical and mechanical properties. Acetone vapor polishing is one of those techniques which is highly beneficial in smoothing ABS 3D-printed parts. Previously, an acetone vapor polishing device has been developed which uses a mist maker. However, for a more efficient polishing method, an optimized vapor polishing device using heat has been fabricated in this study. To assess the efficiency of this device, the researchers test the dimensional accuracy, surface roughness, tensile strength, and impact strength of polished and unpolished ABS 3D-printed specimens. The findings showed that the surface smoothness of the polished cube specimens did not significantly alter its physical geometry. The tensile test reveals that the overall elasticity of the polished tensile specimen has increased significantly while the impact test also shows that the polished specimens have the capacity to sustain a resistive impact from a swinging pendulum. Thus, all testing procedures indicated that post-processing using the optimized vapor polishing device has improved the overall physical and mechanical properties of the polished specimens

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Odanacatib for the treatment of postmenopausal osteoporosis : Results of the LOFT multicentre, randomised, double-blind, placebo-controlled trial and LOFT Extension study

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    Background Odanacatib, a cathepsin K inhibitor, reduces bone resorption while maintaining bone formation. Previous work has shown that odanacatib increases bone mineral density in postmenopausal women with low bone mass. We aimed to investigate the efficacy and safety of odanacatib to reduce fracture risk in postmenopausal women with osteoporosis. Methods The Long-term Odanacatib Fracture Trial (LOFT) was a multicentre, randomised, double-blind, placebo-controlled, event-driven study at 388 outpatient clinics in 40 countries. Eligible participants were women aged at least 65 years who were postmenopausal for 5 years or more, with a femoral neck or total hip bone mineral density T-score between −2·5 and −4·0 if no previous radiographic vertebral fracture, or between −1·5 and −4·0 with a previous vertebral fracture. Women with a previous hip fracture, more than one vertebral fracture, or a T-score of less than −4·0 at the total hip or femoral neck were not eligible unless they were unable or unwilling to use approved osteoporosis treatment. Participants were randomly assigned (1:1) to either oral odanacatib (50 mg once per week) or matching placebo. Randomisation was done using an interactive voice recognition system after stratification for previous radiographic vertebral fracture, and treatment was masked to study participants, investigators and their staff, and sponsor personnel. If the study completed before 5 years of double-blind treatment, consenting participants could enrol in a double-blind extension study (LOFT Extension), continuing their original treatment assignment for up to 5 years from randomisation. Primary endpoints were incidence of vertebral fractures as assessed using radiographs collected at baseline, 6 and 12 months, yearly, and at final study visit in participants for whom evaluable radiograph images were available at baseline and at least one other timepoint, and hip and non-vertebral fractures adjudicated as being a result of osteoporosis as assessed by clinical history and radiograph. Safety was assessed in participants who received at least one dose of study drug. The adjudicated cardiovascular safety endpoints were a composite of cardiovascular death, myocardial infarction, or stroke, and new-onset atrial fibrillation or flutter. Individual cardiovascular endpoints and death were also assessed. LOFT and LOFT Extension are registered with ClinicalTrials.gov (number NCT00529373) and the European Clinical Trials Database (EudraCT number 2007-002693-66). Findings Between Sept 14, 2007, and Nov 17, 2009, we randomly assigned 16 071 evaluable patients to treatment: 8043 to odanacatib and 8028 to placebo. After a median follow-up of 36·5 months (IQR 34·43–40·15) 4297 women assigned to odanacatib and 3960 assigned to placebo enrolled in LOFT Extension (total median follow-up 47·6 months, IQR 35·45–60·06). In LOFT, cumulative incidence of primary outcomes for odanacatib versus placebo were: radiographic vertebral fractures 3·7% (251/6770) versus 7·8% (542/6910), hazard ratio (HR) 0·46, 95% CI 0·40–0·53; hip fractures 0·8% (65/8043) versus 1·6% (125/8028), 0·53, 0·39–0·71; non-vertebral fractures 5·1% (412/8043) versus 6·7% (541/8028), 0·77, 0·68–0·87; all p<0·0001. Combined results from LOFT plus LOFT Extension for cumulative incidence of primary outcomes for odanacatib versus placebo were: radiographic vertebral fractures 4·9% (341/6909) versus 9·6% (675/7011), HR 0·48, 95% CI 0·42–0·55; hip fractures 1·1% (86/8043) versus 2·0% (162/8028), 0·52, 0·40–0·67; non-vertebral fractures 6·4% (512/8043) versus 8·4% (675/8028), 0·74, 0·66–0·83; all p<0·0001. In LOFT, the composite cardiovascular endpoint of cardiovascular death, myocardial infarction, or stroke occurred in 273 (3·4%) of 8043 patients in the odanacatib group versus 245 (3·1%) of 8028 in the placebo group (HR 1·12, 95% CI 0·95–1·34; p=0·18). New-onset atrial fibrillation or flutter occurred in 112 (1·4%) of 8043 patients in the odanacatib group versus 96 (1·2%) of 8028 in the placebo group (HR 1·18, 0·90–1·55; p=0·24). Odanacatib was associated with an increased risk of stroke (1·7% [136/8043] vs 1·3% [104/8028], HR 1·32, 1·02–1·70; p=0·034), but not myocardial infarction (0·7% [60/8043] vs 0·9% [74/8028], HR 0·82, 0·58–1·15; p=0·26). The HR for all-cause mortality was 1·13 (5·0% [401/8043] vs 4·4% [356/8028], 0·98–1·30; p=0·10). When data from LOFT Extension were included, the composite of cardiovascular death, myocardial infarction, or stroke occurred in significantly more patients in the odanacatib group than in the placebo group (401 [5·0%] of 8043 vs 343 [4·3%] of 8028, HR 1·17, 1·02–1·36; p=0·029, as did stroke (2·3% [187/8043] vs 1·7% [137/8028], HR 1·37, 1·10–1·71; p=0·0051). Interpretation Odanacatib reduced the risk of fracture, but was associated with an increased risk of cardiovascular events, specifically stroke, in postmenopausal women with osteoporosis. Based on the overall balance between benefit and risk, the study's sponsor decided that they would no longer pursue development of odanacatib for treatment of osteoporosis
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