Multi-principle component alloys (MPCAs) differ from traditional alloys in that they consist of four or more elements or components each with concentrations of 5–35 at. %. Since the first eutectic ...multi-principle component alloy (MPCA) was produced in 2008, there has been a growing number of papers on developing eutectic MPCAs as potential structural materials. Eutectic MPCAs can show high ambient temperature yield strengths that increase with decreasing interlamellar spacing, λ, according to either λ−1/2 or λ−1, similar to that observed in pearlitic steels, with a tradeoff between this increased strength and reduced tensile ductility. Ambient temperature tensile ductility has been observed in eutectic MPCAs only when one phase is f.c.c. and when the harder second phase is itself deformable. The yield strength in eutectic MPCAs has been shown to decrease with increasing temperature, and, limited data suggest that, this is related to the softening of the harder phase. Annealing of as-cast eutectic MPCAs, which are not typically at equilibrium, can produce precipitation of fine particles that further increase the strength, and which often reduce the ductility. Both thermo-mechanical processing and nitriding can increase the strengths of eutectic MPCAs by transforming the lamellar eutectic into equi-axed grains and producing fine AlN particles (in aluminum-containing MPCAs), respectively. The properties of eutectic MPCAs can largely be explained by models used for traditional alloys. While a number of different elements have been used to produce eutectic MPCAs, the design of eutectic MPCAs for structural applications should avoid the use of expensive elements like cobalt and niobium, which have often been used.
Room temperature yield strengths have been shown to increase with decreasing f.c.c. interlamellar spacing, λ, in lamellar eutectic FeNiMnAl alloys (shown right) according to either λ 1 or λ 1/2, with a resulting trade-off between increased strength and reduced tensile ductility. Display omitted
•The microstructures and mechanical properties of eutectic/eutectoid multi-principle component alloys (MPCAs) are critically reviewed.•The yield strength and interlamellar spacing, λ, of eutectic/eutectoid MPCAs obey a Hall-Petch-type relationship with either a λ−1 or λ-1/2 relationship.•Thermo-mechanical treatments transform the lamellar eutectic into equi-axed two-phase grain structures, leading to either increases or decreases in strength.•Traditional models which relate strength and ductility to the lamellae spacing of the hard and soft phases in mild steels can explain the trade-off between increased yield strength and reduced tensile ductility in eutectic MCPAs.
Patients with limited English proficiency (LEP) experience poorer quality care and more adverse events in hospital. Consequently, there is interest in understanding the role of professional medical ...interpreters in efforts to improve patient safety.
To describe the views of professional medical interpreters on their role in the delivery of safe patient care.
Qualitative analysis of in-depth semi-structured interviews.
15 professional medical interpreters affiliated with the Healthcare Interpretation Network in Toronto, Canada.
Participants' views on their role in patient safety were analyzed and organized into themes.
Professional medical interpreters described being uniquely situated to identify and prevent adverse events involving patients with LEP by: 1) facilitating communication and enhancing patients' comprehension, 2) giving voice to patients, and 3) speaking up about safety concerns. Participants described a tension between 'speaking up' and interpreters' ethical imperative to remain impartial. Interpreters also highlighted several challenges, including 4) medical hierarchy and healthcare providers' limited knowledge of the role of interpreters. These challenges introduced safety issues if providers asked interpreters to act outside of their scope of practice.
Our study found that professional medical interpreters view their work as integral to the delivery of safe care to patients with LEP. In order to effectively engage in patient safety efforts together, interpreters and providers require a mutual understanding of their roles. Team hierarchy and limited provider knowledge of the role of interpreters can introduce safety concerns. In addition, interpreters describe a tension between "speaking up" about patient safety and the need for interpreters to remain impartial when facilitating communication. Healthcare institutions, providers, and interpreters must engage in discussion on how to best to "speak up" and integrate interpreters into safety efforts. Importantly, the benefits of partnering with interpreters can only be realized when providers consistently use their services.
Contaminants such as heavy metals and polycyclic aromatic hydrocarbons (PAHs) can be released from asphalt pavement and transported through stormwater runoff to nearby water bodies, leading to water ...pollution and potential harm to living aquatic animals. This study characterizes the heavy metal and PAH leaching from various asphalt paving materials and their potential ecotoxicological effects on zebrafish Danio rerio. Artificial runoffs were prepared in the laboratory concerning the effects of water, temperature, and traffic. The concentrations of heavy metals and PAHs in the leachates were quantified, while the toxicity assessment encompassed mortality, metal stress, PAH toxicity, inflammation, carcinogenicity, and oxidative damage. Gene expressions of related proteins or transcription factors were assessed, including metallothionines, aryl hydrocarbon receptors, interleukin-1β, interleukin-10, nuclear factor-κB, tumor necrosis factor-α, tumor suppressor p53, heat shock protein 70, and reactive oxygen species (ROS). The findings demonstrate that leachates from asphalt pavements containing waste bottom ash, crumb rubber, or specific chemicals could induce notable stress and inflammation responses in zebrafish. In addition, potential carcinogenic effects and the elevation of ROS were identified within certain treatment groups. This study represents the first attempt to assess the ecotoxicity of pavement leachates employing a live fish model, thereby improving the current understanding of the environmental impact of asphalt pavements.
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•Pollutant leaching from asphalt pavements under near-true conditions was simulated.•Ecotoxicological effects of leachates on aquatic vertebrates were assessed.•The integration of bottom ash induced pro-inflammatory responses in zebrafish.•The incorporation of waste rubber chemicals induced considerable stress in zebrafish.•Potential carcinogenic effects were identified that need further investigation.
In large-scale assessments, such as state-wide testing programs, national sample-based assessments, and international comparative studies, there are many steps involved in the measurement and ...reporting of student achievement. There are always sources of inaccuracies in each of the steps. It is of interest to identify the source and magnitude of the errors in the measurement process that may threaten the validity of the final results. Assessment designers can then improve the assessment quality by focusing on areas that pose the highest threats to the results. This paper discusses the relative magnitudes of three main sources of error with reference to the objectives of assessment programs: measurement error, sampling error, and equating error. A number of examples from large-scale assessments are used to illustrate these errors and their impact on the results. The paper concludes by making a number of recommendations that could lead to an improvement of the accuracies of large-scale assessment results. Author abstract
Ceramides contribute to the lipotoxicity that underlies diabetes, hepatic steatosis, and heart disease. By genetically engineering mice, we deleted the enzyme dihydroceramide desaturase 1 (DES1), ...which normally inserts a conserved double bond into the backbone of ceramides and other predominant sphingolipids. Ablation of DES1 from whole animals or tissue-specific deletion in the liver and/or adipose tissue resolved hepatic steatosis and insulin resistance in mice caused by leptin deficiency or obesogenic diets. Mechanistic studies revealed ceramide actions that promoted lipid uptake and storage and impaired glucose utilization, none of which could be recapitulated by (dihydro)ceramides that lacked the critical double bond. These studies suggest that inhibition of DES1 may provide a means of treating hepatic steatosis and metabolic disorders.
The microstructure and mechanical properties studies of a series of two-phase f.c.c./B2 (ordered b.c.c.) lamellar-structured, high entropy alloys (HEA) Fe36Ni18Mn33Al13Tix with x up to 6 at. % Ti ...have been investigated. X-ray microanalysis in a TEM showed that the Ti resided mostly in the B2 phase. The lamellar spacing decreased significantly with increasing Ti content from 1.56 μm for the undoped alloy to 155 nm with an addition of 4 at. % Ti, leading to a sharp increase in room-temperature yield strength,σy, from 270 MPa to 953 MPa, but with a concomitant decrease in ductility from 22% elongation to 2.3%. Annealing at 1173 K for 20 h greatly increased the lamellar spacing of Fe36Ni18Mn33Al13Ti4 to 577 nm, producing a corresponding decrease in σy to 511 MPa. The yield strengths of all the doped alloys decreased significantly when tensile tested at 973 K with a concomitant increase in ductility due to softening of the B2 phase. The fracture mode changed from cleavage at room temperature to a ductile dimple-type rupture at 973 K. The results are discussed in terms of the Hall-Petch-type relationship.
•The lamellar spacing decreased significantly with increasing Ti content.•Ti resided mostly in the B2 phase.•Ti led to a sharp increase in room-temperature yield strength (up to 953 MPa).•The strengthening effect of Ti on the yield strength can be described by a Hall-Petch-type relationship.
Australia has declared its ambition to be within the 'top five' in the Programme for International Student Assessment (PISA) by 2025. So serious is it about this ambition, that the Australian ...Government has incorporated it into the Australian Education Act, 2013. Given this focus on PISA results and rankings, we go beyond average scores to take a close look at Australia's performance in PISA, examining rankings by different geographical units, by item content and by test completion. Based on this analysis and using data from interviews with measurement and policy experts, we show how uninformative and even misleading the 'average performance scores', on which the rankings are based, can be. We explore how a more nuanced understanding would point to quite different policy actions. After considering the PISA data and Australia's 'top five' ambition closely, we argue that neither the rankings nor such ambitions should be given much credence.
The alumina-forming austenitic stainless steel Fe-20Cr-30Ni-2 Nb-5Al was given a solutionizing anneal at 1250 °C followed by anneals at 800 °C for 0, 2.4, 24, 240 h to produce B2 (ordered b.c.c.) and ...Laves phase precipitates of different sizes with different extents of grain boundary coverage. Both tensile tests and constant-stress (43 MPa) creep tests were performed on the heat-treated materials and on the as-cast alloy at 760 °C. The precipitates grew during the creep testing. In addition, L12 (ordered f.c.c.) precipitates nucleated and grew during the creep testing to similar particle sizes after 500 h independent of the prior heat treatment at 800 °C. The specimens given the shortest heat treatment of 2.4 h, which had the smallest initial particle sizes, showed both the highest yield strength and the smallest creep strain after 500 h. The extent of grain boundary coverage by precipitates did not appear to affect the creep rates. No grain boundary cracking or precipitate cracking was found in the heat-treated specimens after creep testing, but the as-cast material failed around 600 h.
Food emulsifiers like glycerol monostearate (G) and Tween 80 (TW) are commonly used to help formation and maintain stability of emulsions. However, certain food contaminants and emulsifiers often ...co-occur in the same food item due to food culture and cooking methods. For this reason, the present study investigated interaction of toxic effect of emulsifiers (G and TW) and process contaminants (acrylamide (AA) and benzo apyrene (BAP)) on zebrafish. Adult zebrafish were exposed to emulsifiers, food contaminants, or the combination through diet for 2 h and 7 days. Oxidative stress and inflammation caused by food contaminants were increased when food emulsifiers were present. These combined treatments also induced more severe morphological changes than the contaminant alone treatments. In the gut, disruption of villi structure and increased number of goblet cells was observed and in the liver there were increased lipid deposition, infiltration of immune cells, glycogen depletion and focal necrosis. Increased accumulation of AA and BAP in the liver and gut were detected after addition of emulsifiers, suggesting that emulsifiers can enhance absorption of diet-borne contaminants. Our results showed food emulsifiers and contaminants can interact synergistically and increase risk.
Hyperglucagonemia is implicated in the pathophysiology of hyperglycemia. Antagonism of the glucagon receptor (GCGR) thus represents a potential approach to diabetes treatment. Herein we report the ...characterization of GRA1, a novel small-molecule GCGR antagonist that blocks glucagon binding to the human GCGR (hGCGR) and antagonizes glucagon-induced intracellular accumulation of cAMP with nanomolar potency. GRA1 inhibited glycogenolysis dose-dependently in primary human hepatocytes and in perfused liver from hGCGR mice, a transgenic line of mouse that expresses the hGCGR instead of the murine GCGR. When administered orally to hGCGR mice and rhesus monkeys, GRA1 blocked hyperglycemic responses to exogenous glucagon. In several murine models of diabetes, acute and chronic dosing with GRA1 significantly reduced blood glucose concentrations and moderately increased plasma glucagon and glucagon-like peptide-1. Combination of GRA1 with a dipeptidyl peptidase-4 inhibitor had an additive antihyperglycemic effect in diabetic mice. Hepatic gene-expression profiling in monkeys treated with GRA1 revealed down-regulation of numerous genes involved in amino acid catabolism, an effect that was paralleled by increased amino acid levels in the circulation. In summary, GRA1 is a potent glucagon receptor antagonist with strong antihyperglycemic efficacy in preclinical models and prominent effects on hepatic gene-expression related to amino acid metabolism.
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