308 research outputs found

    Debinding process of ss316L metal injection moulding under argon atmosphere

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    Solvent and thermal debinding acted as binder in removing Restaurant Waste Lipid (RWL) and Polypropylene (PP) from the stainless steel 316L. This investigation was carried out to determine the effect of thermal debinding variables on density, shrinkage and surface morphology of the brown parts other than to remove the binder from the SS316L under the Argon atmosphere with flow rate of 5 ml/min. The parameter used for solvent debinding process was solvent temperature at 60°C for six hours, while thermal debinding process was conducted at various temperature of 400°C, 500°C and 600°C, heating rate of 10 °C/min, 20 °C/min and 30 °C/min, dwell time of 30 min, 60 min and 90 min, and cooling rate of 5 °C/min, 10 °C/min and 15 °C/min. Analysis of weight loss percentage was done on the brown part after the solvent debinding and thermal debinding processes. Scanning Electron Microscope (SEM) was used to confirm the removal of RWL and PP from the compacts based on the porosity form, and attachment of PP in the powder particles. This investigation showed that debinding parameters were important in terms of their effects on the physical properties. Based on the observation through SEM and consideration of the factors that affected the physical properties of the parts, it was found that RWL was completely extracted out at 60°C for six hours, while the thermal temperature of 500°C with heating rate of 10 °C/min, dwell time of 60 min and cooling rate of 15 °C/min were the optimal thermal debinding parameters in PP removal

    Solar Jet Hunter: a citizen science initiative to identify coronal jets in EUV data sets

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    Context. Solar coronal jets seen in EUV are ubiquitous on the Sun, have been found in and at the edges of active regions, at the boundaries of coronal holes, and in the quiet Sun. Jets have various shapes, sizes, brightness, velocities and duration in time, which complicates their detection by automated algorithms. So far, solar jets reported in the Heliophysics Event Knowledgebase (HEK) have been mostly reported by humans looking for them in the data, with different levels of precision regarding their timing and positions. Aims. We create a catalogue of solar jets observed in EUV at 304 {\AA} containing precise and consistent information on the jet timing, position and extent. Methods. We designed a citizen science project, "Solar Jet Hunter", on the Zooniverse platform, to analyze EUV observations at 304 {\AA} from the Solar Dynamic Observatory/Atmospheric Imaging Assembly (SDO/AIA). We created movie strips for regions of the Sun in which jets have been reported in HEK and ask the volunteers to 1) confirm the presence of at least one jet in the data and 2) report the timing, position and extent of the jet. Results. We report here the design of the project and the results obtained after the analysis of data from 2011 to 2016. 365 "coronal jet" events from HEK served as input for the citizen science project, equivalent to more than 120,000 images distributed into 9,689 "movie strips". Classification by the citizen scientists resulted with only 21% of the data containing a jet, and 883 individual jets being identified. Conclusions. We demonstrate how citizen science can enhance the analysis of solar data with the example of Solar Jet Hunter. The catalogue of jets thus created is publicly available and will enable statistical studies of jets and related phenomena. This catalogue will also be used as a training set for machines to learn to recognize jets in further data sets

    Community owned solutions for fire management in tropical ecosystems:case studies from Indigenous communities of South America

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    Fire plays an increasingly significant role in tropical forest and savanna ecosystems, contributing to greenhouse gas emissions and impacting on biodiversity. Emerging research shows the potential role of Indigenous land use practices for controlling deforestation and reducing CO2 emissions. Analysis of satellite imagery suggests that Indigenous lands have the lowest incidence of wildfires, significantly contributing to maintaining carbon stocks and enhancing biodiversity. Yet, acknowledgement of Indigenous peoples’ role in fire management and control is limited, and in many cases dismissed, especially in policy-making circles. In this paper, we review existing data on Indigenous fire management and impact, focusing on examples from tropical forest and savanna ecosystems in Venezuela, Brazil and Guyana. We highlight how the complexities of community owned solutions for fire management are being lost as well as undermined by continued efforts on fire suppression and firefighting, and emerging approaches to incorporate Indigenous fire management into market, incentive-based for climate change mitigation. Our aim is to build a case for supporting Indigenous fire practices within all scales of decision-making by strengthening Indigenous knowledge systems to ensure more effective and sustainable fire management

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Antioxidant activity and hepatoprotective potential of agaro-oligosaccharides in vitro and in vivo

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    BACKGROUND: Agaro-oligosaccharides derived from red seaweed polysaccharide have been reported to possess antioxidant activity. In order to assess the live protective effects of agar-oligosaccharides, we did both in vitro and in vivo studies based on own-made agaro-oligosaccharides, and the structural information of this oligosaccharide was also determined. METHOD: Structure of agaro-oligosaccharides prepared with acid hydrolysis on agar was confirmed by matrix-assisted ultraviolet laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) and NMR. The antioxidant effect of agaro-oligosaccharides on intracellular reactive oxygen species (ROS) was assessed by 2', 7'-dichlorofluorescin diacetate. Carbon tetrachloride was used to induce liver injury, some index including SOD, GSH-Px, MDA, AST, ALT were examined to determine the hepatoprotective effect of agaro-oligosaccharides. RESULTS: Agaro-oligosaccharides we got were composed of odd polymerizations with molecular weights ranged from 500 to 2500. Results from intracellular test indicated that agaro-oligosaccharides could significantly scavenge the level of oxidants in the hepatocytes, more beneficially, also associated with the improvement of cell viability In vivo studies of the antioxidant effects on tissue peroxidative damage induced by carbon tetrachloride in rat model indicated that agaro-oligosaccharides could elevate the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and decrease the level of malondialdehyde (MDA), glutamate oxaloacetate transaminase (AST), glutamic pyruvic transaminase (ALT) significantly. At 400 mg/kg, MDA level reduced 44 % and 21 % in liver and heart, SOD and GSH-Px increased to highest in liver and serum, while ALT level decreased 22.16 % in serum. CONCLUSION: Overall, the results of the present study indicate that agaro-oligosaccharides can exert their in vitro and in vivo hepatoprotective effect through scavenging oxidative damage induced by ROS

    Identification of metabolic engineering targets through analysis of optimal and sub-optimal routes

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    Identification of optimal genetic manipulation strategies for redirecting substrate uptake towards a desired product is a challenging task owing to the complexity of metabolic networks, esp. in terms of large number of routes leading to the desired product. Algorithms that can exploit the whole range of optimal and suboptimal routes for product formation while respecting the biological objective of the cell are therefore much needed. Towards addressing this need, we here introduce the notion of structural flux, which is derived from the enumeration of all pathways in the metabolic network in question and accounts for the contribution towards a given biological objective function. We show that the theoretically estimated structural fluxes are good predictors of experimentally measured intra-cellular fluxes in two model organisms, namely, Escherichia coli and Saccharomyces cerevisiae. For a small number of fluxes for which the predictions were poor, the corresponding enzyme-coding transcripts were also found to be distinctly regulated, showing the ability of structural fluxes in capturing the underlying regulatory principles. Exploiting the observed correspondence between in vivo fluxes and structural fluxes, we propose an in silico metabolic engineering approach, iStruF, which enables the identification of gene deletion strategies that couple the cellular biological objective with the product flux while considering optimal as well as sub-optimal routes and their efficiency.This work was supported by the Portuguese Science Foundation [grant numbers MIT-Pt/BS-BB/0082/2008, SFRH/BPD/44180/2008 to ZS] (http://www.fct.pt/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Impact of episiotomy on pelvic floor disorders and their influence on women's wellness after the sixth month postpartum: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>The role of episiotomy as a protective factor against pelvic floor disorders postpartum has been debated for many years, but its routine use has been hitherto discouraged in the literature. Comparisons between restrictive and routine use of episiotomy in existent literature, however, fail to include any consideration relating to quality of life. The aim of this study, therefore, is to state the role of episiotomy in preserving the perineum from damage, in order to prevent the influence of pelvic floor disorders on women's psycho-physical wellness after the sixth month postpartum.</p> <p>Methods</p> <p>A follow-up telephone interview was performed among 377 primiparous and secondiparous Caucasian women who had a child by spontaneous or operative vaginal delivery in 2006 using a self-created questionnaire and King's Health Questionnaire (KHQ).</p> <p>Results</p> <p>The mean age at delivery was 35.26 (±4.68) years and episiotomy was performed in 59.2% of women. Multivariate linear regression shows episiotomy associated to higher quality of life after the sixth month postpartum by correlating with inferior values of King's Health Questionnaire (p < 0.05).</p> <p>Conclusions</p> <p>Episiotomy appears to be a protective factor for women's wellness. Women who had episiotomy and who experienced perineal symptoms have a better psycho-physical health status in the 12.79 months (±3.3) follow-up.</p

    Population Pharmacokinetics of Alemtuzumab (Campath) in Pediatric Hematopoietic Cell Transplantation: Towards Individualized Dosing to Improve Outcome

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    BACKGROUND AND OBJECTIVE: Alemtuzumab (Campath®) is used to prevent graft-versus-host disease and graft failure following pediatric allogeneic hematopoietic cell transplantation. The main toxicity includes delayed immune reconstitution, subsequent viral reactivations, and leukemia relapse. Exposure to alemtuzumab is highly variable upon empirical milligram/kilogram dosing. METHODS: A population pharmacokinetic (PK) model for alemtuzumab was developed based on a total of 1146 concentration samples from 206 patients, aged 0.2-19 years, receiving a cumulative intravenous dose of 0.2-1.5 mg/kg, and treated between 2003 and 2015 in two centers. RESULTS: Alemtuzumab PK were best described using a two-compartment model with a parallel saturable and linear elimination pathway. The linear clearance pathway, central volume of distribution, and intercompartmental distribution increased with body weight. Blood lymphocyte counts, a potential substrate for alemtuzumab, did not impact clearance. CONCLUSION: The current practice with uniform milligram/kilogram doses leads to highly variable exposures in children due to the non-linear relationship between body weight and alemtuzumab PK. This model may be used for individualized dosing of alemtuzumab
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