Two-step sinter-crystallization of K2O–CaO–P2O5–SiO2 (45S5-K) bioactive glass

Bioactive glasses and glass-ceramics (GCs) effectively regenerate bone tissue, however most GCs show improved mechanical properties. In this work, we developed and tested a rarely studied bioactive glass composition (24.4K₂O-26.9CaO-46.1SiO₂-2.6P₂O₅ mol%, identified as 45S5-K) with different particle sizes and heating rates to obtain a sintered GC that combines good fracture strength, low elastic modulus, and bioactivity. We analyzed the influence of the sintering processing conditions in the elastic modulus, Vickers microhardness, density, and crystal phase formation in the GC. The best GC shows improved properties compared with its parent glass. This glass achieves a good densification degree with a two-step viscous flow sintering approach and the resulting GC shows as high bioactivity as that of the standard 45S5 Bioglass®. Furthermore, the GC elastic modulus (56 GPa) is relatively low, minimizing stress shielding. Therefore, we unveiled the glass sintering behavior with concurrent crystallization of this complex bioactive glass composition and developed a potential GC for bone regeneration.     

Update on the Diagnostic Pitfalls of Autopsy and Post-Mortem Genetic Testing in Cardiomyopathies

Inherited cardiomyopathies are frequent causes of sudden cardiac death (SCD), especially in young patients. Despite at the autopsy they usually have distinctive microscopic and/or macroscopic diagnostic features, their phenotypes may be mild or ambiguous, possibly leading to misdiagnoses or missed diagnoses. In this review, the main differential diagnoses of hypertrophic cardiomyopathy (e.g., athlete’s heart, idiopathic left ventricular hypertrophy), arrhythmogenic cardiomyopathy (e.g., adipositas cordis, myocarditis) and dilated cardiomyopathy (e.g., acquired forms of dilated cardiomyopathy, left ventricular noncompaction) are discussed. Moreover, the diagnostic issues in SCD victims affected by phenotype-negative hypertrophic cardiomyopathy and the relationship between myocardial bridging and hypertrophic cardiomyopathy are analyzed. Finally, the applications/limits of virtopsy and post-mortem genetic testing in this field are discussed, with particular attention to the issues related to the assessment of the significance of the genetic variants.     

Sliding-wear resistance of pure near fully-dense B4C under lubrication with water,diesel fuel,and paraffin oil

The sliding-wear resistance of pure near fully-dense B₄C is investigated, and the wear mode/mechanisms identified, under lubrication with water, diesel fuel, and paraffin oil. It is found that the wear is mild in the three cases, with specific wear rates (SWRs) of 10^?16–10^?17 m³/N m. Nonetheless, the wear resistance of the B₄C ceramic is one order of magnitude greater under oil lubrication (10¹⁶ N m/m³) than under water lubrication (10¹⁵ N m/m³), and twice as great for the specific case of paraffin oil than diesel fuel, attributable to the lubricant’s viscosity. It is also found that the wear mode is always abrasion, and that the wear mechanisms are plastic deformation and localized fracture with grain pullout. However, in agreement with the macro-wear data, the severity of the wear damage is lower under lubrication with paraffin oil, followed by diesel fuel, and lastly water. Finally, microstructural considerations are discussed with a view to enhancing the sliding-wear resistance of B₄C triboceramics.     

Solvent Extraction of Copper from Sulfate–Chloride Solutions Using LIX 84-IC and LIX 860-IC

ABSTRACT

The effect of chloride ions on the copper extraction equilibria, the rate of extraction, copper/iron selectivity, and chloride extraction was studied for organic phases containing pure ketoxime (LIX 84-IC) and pure nonylaldoxime (LIX 860N-IC). In these systems, the used aqueous phase contained total chloride concentrations from 0 to 110 g/l. It was determined that the chloride ions in the aqueous solution had a large negative effect on the extraction equilibria for LIX 84-IC and a small effect for LIX 860N-IC. This deleterious effect is attributed to an increase in the hydrogen ion activity coefficient in the presence of chloride ions. The chloride accelerated the rate of copper extraction even though the reaction was fast in all the tested conditions. An increase in the temperature from 25°C to 35°C affected positively the extraction equilibria for LIX 84-IC.     

Rare Titin (TTN) Variants in Diseases Associated with Sudden Cardiac Death

A leading cause of death in western countries is sudden cardiac death, and can be associated with genetic disease. Next-generation sequencing has allowed thorough analysis of genes associated with this entity, including, most recently, titin. We aimed to identify potentially pathogenic genetic variants in titin. A total of 1126 samples were analyzed using a custom sequencing panel including major genes related to sudden cardiac death. Our cohort was divided into three groups: 432 cases from patients with cardiomyopathies, 130 cases from patients with channelopathies, and 564 post-mortem samples from individuals showing anatomical healthy hearts and non-conclusive causes of death after comprehensive autopsy. None of the patients included had definite pathogenic variants in the genes analyzed by our custom cardio-panel. Retrospective analysis comparing the in-house database and available public databases also was performed. We identified 554 rare variants in titin, 282 of which were novel. Seven were previously reported as pathogenic. Of these 554 variants, 493 were missense variants, 233 of which were novel. Of all variants identified, 399 were unique and 155 were identified at least twice. No definite pathogenic variants were identified in any of genes analyzed. We identified rare, mostly novel, titin variants that seem to play a potentially pathogenic role in sudden cardiac death. Additional studies should be performed to clarify the role of these variants in sudden cardiac death.     

Assessment of Mineralogical,Textural, and Water Chemistry Changes During Long-Distance Tailings-Slurry Transport

An exploratory study demonstrated that subtle changes in solids and process water were caused by long-distance turbulent transport of tailings from the concentrator to the impoundment of a Cu (Mo) porphyry copper deposit. Slurry water chemical analysis was complemented by modelling potential phase precipitation or dissolution and speciation of dissolved metals. It was found that transport did not affect major insoluble mineral phases. However, the degrees of liberation of several phyllosilicates, as determined by automated mineralogy, were reduced close to the impoundment, which points to separation of clay particles from tectosilicate surfaces by the turbulence; this also was observed by SEM examination of micro-aggregate specimens. Reduction of maximum particle sizes, increased N2 monolayer adsorption, and resultant specific surface areas indicate that transport modified the micro-aggregates. Major element water chemistry is controlled by the presence of soluble mineral phases, such as gypsum, and reagents, such as lime, in the flotation process. Changes in the dissolved concentrations of some elements could potentially affect tailings deportment in the impoundment. Increased concentrations of Al may affect the clay settling behaviour, while Mo and As levels will require treatment prior to the discharge of water from the tailings impoundment. This study demonstrated that systematic scrutiny of tailings slurries leaving the concentrator and before entering the impoundment can be potentially useful, though care will have to be exercised to replicate sample handling and analytical conditions, during any long-term monitoring.     

Mathematical foundations of moral preferences

One-shot anonymous unselfishness in economic games is commonly explained by social preferences, which assume that people care about the monetary pay-offs of others. However, during the last 10 years, research has shown that different types of unselfish behaviour, including cooperation, altruism, truth-telling, altruistic punishment and trustworthiness are in fact better explained by preferences for following one''s own personal norms—internal standards about what is right or wrong in a given situation. Beyond better organizing various forms of unselfish behaviour, this moral preference hypothesis has recently also been used to increase charitable donations, simply by means of interventions that make the morality of an action salient. Here we review experimental and theoretical work dedicated to this rapidly growing field of research, and in doing so we outline mathematical foundations for moral preferences that can be used in future models to better understand selfless human actions and to adjust policies accordingly. These foundations can also be used by artificial intelligence to better navigate the complex landscape of human morality.