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Abstract This study explores cold sintering of naturally occurring minerals as supplementary cementitious materials (SCM) or cement analogs, which have the potential to transform the traditional high‐energy, high‐emission cement manufacturing pathways. Diopside (MgCaSi₂O₆), a natural inosilicate, is used as the model system. As diopside is hard for cold sintering directly (by itself), this study demonstrates that the addition of amorphous silica nanoparticles can enable cold sintering of diopside. The cold‐sintered diopside–silica composites are characterized by X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The effect of the relative weight percentage of silica added is examined. The relative density of the cold‐sintered composite reaches nearly 90% at 400 MPa and 200°C in 60 min. For specimens with the addition of 30 wt% or more of amorphous SiO₂, cold sintering also induces partial crystallization, converting a fraction of amorphous silica to quartz. The crystallization kinetics exhibits a stochastic nature. The Vickers hardness of the cold‐sintered diopside–silica composite increases with increasing amount of silica, whichpromotes cold sintering, reaching ∼3 GPa with 20 wt% or more silica. The diopside–silica composites studied here serve as a model system for metal‐leached silicate mine tailings, which are expected to have nanoporous amorphous silica shells on silicate particles to enable the silica‐assisted cold sintering mechanism discovered in this study. 

Non-stoichiometric perovskite oxides have been studied as a new family of redox oxides for solar thermochemical hydrogen (STCH) production owing to their favourable thermodynamic properties. However, conventional perovskite oxides suffer from limited phase stability and kinetic properties, and poor cyclability. Here, we report a strategy of introducing A-site multi-principal-component mixing to develop a high-entropy perovskite oxide, (La1/6Pr1/6Nd1/6Gd1/6Sr1/6Ba1/6)MnO3 (LPNGSB_Mn), which shows desirable thermodynamic and kinetics properties as well as excellent phase stability and cycling durability. LPNGSB_Mn exhibits enhanced hydrogen production (∼77.5 mmol/mol-oxide) compared to (La2/3Sr1/3)MnO3 (∼53.5 mmol / mol-oxide) in a short 1 hour redox duration and high STCH and phase stability for 50 cycles. LPNGSB_Mn possesses a moderate enthalpy of reduction (252.51–296.32 kJ / mol-oxide), a high entropy of reduction (126.95–168.85 J / mol-oxide), and fast surface oxygen exchange kinetics. All A-site cations do not show observable valence changes during the reduction and oxidation processes. This research preliminarily explores the use of one A-site high-entropy perovskite oxide for STCH. 

Abstract Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide an excellent platform for potential clinical and research applications. Identifying abnormal Ca²⁺transients is crucial for evaluating cardiomyocyte function that requires labor-intensive manual effort. Therefore, we develop an analytical pipeline for automatic assessment of Ca²⁺transient abnormality, by employing advanced machine learning methods together with an Analytical Algorithm. First, we adapt an existing Analytical Algorithm to identify Ca²⁺transient peaks and determine peak abnormality based on quantified peak characteristics. Second, we train a peak-level Support Vector Machine (SVM) classifier by using human-expert assessment of peak abnormality as outcome and profiled peak variables as predictive features. Third, we train another cell-level SVM classifier by using human-expert assessment of cell abnormality as outcome and quantified cell-level variables as predictive features. This cell-level SVM classifier can be used to assess additional Ca²⁺transient signals. By applying this pipeline to our Ca²⁺transient data, we trained a cell-level SVM classifier using 200 cells as training data, then tested its accuracy in an independent dataset of 54 cells. As a result, we obtained 88% training accuracy and 87% test accuracy. Further, we provide a free R package to implement our pipeline for high-throughput CM Ca²⁺analysis.