Recent multi-principal element, high entropy alloy (HEA) development strategies vastly expand the number of candidate alloy systems, but also pose a new challenge--how to rapidly screen thousands of ...candidate alloy systems for targeted properties. Here we develop a new approach to rapidly assess structural metals by combining calculated phase diagrams with simple rules based on the phases present, their transformation temperatures and useful microstructures. We evaluate over 130,000 alloy systems, identifying promising compositions for more time-intensive experimental studies. We find the surprising result that solid solution alloys become less likely as the number of alloy elements increases. This contradicts the major premise of HEAs--that increased configurational entropy increases the stability of disordered solid solution phases. As the number of elements increases, the configurational entropy rises slowly while the probability of at least one pair of elements favouring formation of intermetallic compounds increases more rapidly, explaining this apparent contradiction.
The northwestern Indian Ocean hosts globally crucial marine biodiversity, which is relatively understudied. There has, however, been significant research and conservation effort focused on marine ...turtles across the region in recent decades. We undertook an exhaustive review of 251 relevant publications to extract and collate the current information concerning marine turtles. To ensure completeness, we received input on a preliminary draft from a large group of experts who have worked extensively in the region. Data presented here are from all 13 countries with significant coastlines in the region (Bahrain, Djibouti, Egypt, Eritrea, Iran, Kuwait, Oman, Qatar, Saudi Arabia, Somalia, Sudan, United Arab Emirates, and Yemen) on occurrence, nesting biology, morphology, foraging areas, population status, threats, and relevant national legislation and international conservation strategies. The experts independently provided details on what they felt were the (1) most significant threats to marine turtles, (2) most critical knowledge gaps for marine turtle ecology, (3) impediments to practical conservation, and (4) essential strengths and opportunities in the region.
Direct determination of exposed grain surface area is a difficult task to achieve since the exposed surface area of grains in multiphase particles can only be accurately analyzed in three dimensions. ...Now, due to advances in high resolution X-ray microtomography (HRXMT), with a voxel resolution of ~1μm it is possible to identify dispersed grains as small as 5μm in multiphase particles and quantify their surface area exposure in 3D. In this paper, the development of procedures for detailed analysis to quantify the extent of grain surface area exposure using HRXMT is described. Image analysis procedures, including preprocessing of the 3D tomographic images, correction for the partial volume effect (PVE), and the use of a new algorithm for determination of exposed grain surface area measurement, are discussed.
Application of the procedure is illustrated with the analysis of flotation products from HydroFloat (HF) experiments for an auriferous pyrite ore. The results demonstrate that two levels of analysis are appropriate for understanding the flotation of locked particles. First, the particle distribution with respect to exposed grain surface area, expressed as a percentage of the total particle surface area, should be considered. Second, the grain distribution with respect to actual exposed surface area should be considered in order to account for the stability of attached bubbles and recovery of such multiphase particles in the concentrate.
With the development of appropriate image processing procedures, determination of exposed grain surface area of multiphase particles is now possible from high resolution X-ray tomography data. Display omitted
•3D exposed grain surface area algorithm developed for multiphase particles•New algorithm was used to evaluate flotation products.•Exposed grain surface area analysis explains coarse particle flotation.
Global increases in beach sand temperatures are predicted to skew hatchling sex ratios of marine turtle populations towards female bias. Currently, shade structures and freshwater irrigation are ...management strategies used to cool nest temperatures, but require resources that are limited at remote rookeries. Here, we report on a novel investigation that used seawater irrigation as a sand-cooling method. Various volumes of seawater were applied to sand to determine the optimal application required to lower sand temperatures at nest depth to produce male-biased sex ratios. We performed these experiments during the 2019-2020 nesting season at Heron Island on the southern Great Barrier Reef, Australia, and at Panasesa Island, Papua New Guinea. We found the amount of cooling at nest depth was site dependent and varied with the seawater irrigation regime used. At Heron Island, we used a one-off application of the equivalent of 120 mm of rainfall either as freshwater or seawater to the sand above incubating clutches 18 d after oviposition to determine whether this affected the hatching success of green turtle
Chelonia mydas
eggs. Both treatments had higher hatching success (83.8 ± 3.5% and 71.2 ± 6.3%, respectively, means ± SE) compared to control clutches (63.5 ± 6.0%). Our results indicate that a one-off application of seawater may be an effective management option for reducing nest temperatures during the sex-determining period of marine turtle clutches incubating
in situ
. Seawater irrigation could be used in areas where populations are at highest risk of feminisation caused by a hot drying climate where freshwater is not available for irrigation.
Over the last four decades, a substantial body of national survey material has been collected in the US concerning the public understanding of science and technology. Using this body of research, ...this analysis outlines the major trends from 1957 to 1999 and discusses their implications for public understanding of, and attitudes toward, scientific research. The analysis found that although the rate of civic scientific literacy in the US is only now approaching 20 percent, there is a strong and continuing public belief in the value of scientific research for economic prosperity and for the quality of life. Even though there are some continuing reservations about the pace of change engendered by science and technology and the relationship between science and faith, the public consistently reconciles these differing perceptions in favor of science.
A case report involving a 34-year-old white male who was found dead at home by his roommate is presented. At the time of his death, he was being treated with tramadol/acetaminophen, metaxalone, ...oxycodone, and amitriptyline. The decedent's mother stated that he had been taking increasing amounts of pain medication in order to sleep at night. There were no significant findings at autopsy; however, toxicology results supported a cause and manner of death resulting from suicidal mixed tramadol and amitriptyline toxicity. This case reports the tissue and fluid distribution of tramadol, amitriptyline, and their metabolites in an acutely fatal ingestion in an effort to document concentrations of these analytes in 12 matrices with respect to one another to assist toxicologists in difficult interpretations.
Background & Aims The ability to obtain unlimited numbers of human hepatocytes would improve the development of cell-based therapies for liver diseases, facilitate the study of liver biology, and ...improve the early stages of drug discovery. Embryonic stem cells are pluripotent, potentially can differentiate into any cell type, and therefore could be developed as a source of human hepatocytes. Methods To generate human hepatocytes, human embryonic stem cells were differentiated by sequential culture in fibroblast growth factor 2 and human activin-A, hepatocyte growth factor, and dexamethasone. Functional hepatocytes were isolated by sorting for surface asialoglycoprotein-receptor expression. Characterization was performed by real-time polymerase chain reaction, immunohistochemistry, immunoblot, functional assays, and transplantation. Results Embryonic stem cell–derived hepatocytes expressed liver-specific genes, but not genes representing other lineages, secreted functional human liver–specific proteins similar to those of primary human hepatocytes, and showed human hepatocyte cytochrome P450 metabolic activity. Serum from rodents given injections of embryonic stem cell–derived hepatocytes contained significant amounts of human albumin and α1-antitrypsin. Colonies of cytokeratin-18 and human albumin–expressing cells were present in the livers of recipient animals. Conclusions Human embryonic stem cells can be differentiated into cells with many characteristics of primary human hepatocytes. Hepatocyte-like cells can be enriched and recovered based on asialoglycoprotein-receptor expression and potentially could be used in drug discovery research and developed as therapeutics.
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