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Limiting global warming to 1.5-2 °C requires a 50-90% reduction in CO2 emissions in 2050, depending on different scenarios, and carbon capture, utilization, and storage is a promising technology that can help reach this objective. Calcium oxide (CaO) carbon capture is an appealing choice because of its affordability, large potential capacity, and ability to withstand the high temperatures of flue gases. However, the structural instability and capacity fading challenge its large-scale industrial applications. Here, we design a reversible reaction shuttle in CaO-based sorbents to improve the structure stability by changing the initial alumina phases. Diverse alumina phases (x-Al2O3) are first synthesized and utilized as the aluminum source for creating CaO@x-Al2O3 composites. As expected, the CaO@δ-Al2O3 composite demonstrates a carbon capture capacity of 0.43 g-CO2/g-sorbent after 50 cycles, with an impressive capacity retention of 82.7%. Combined characterizations and calculations reveal that this stability improvement is attributed to a transition shuttle between Ca3Al2O6 and Ca5Al6O14, which can effectively restrain the complete decompositions of those structure-stabilized intermediate phases. An economic assessment further identifies the significance of heat transfer efficiency improvement upon cycles, and control of capital/operation cost, energy price and carbon tax for a future cost-effective commercialization of current strategy. Distinct alumina phases lead to various intermediate phases in the CaO@x-Al2O3 composites. Here authors show that δ-Al2O3 induces a transition shuttle between Ca3Al2O6 and Ca5Al6O14 in a classical CaO-Al2O3 system, thus improving its carbon capture stabilities. [ABSTRACT FROM AUTHOR]

The elemental distributions among various phases in vanadium-bearing slags have been quantified toward high-efficiency separation and extraction by calcium roasting using electron probe X-ray microanalysis. The roles of the roasting conditions were clarified, including roasting temperature, roasting time, and calcium amount. It was found that, with increasing roasting temperature, the V2O5 concentration in the target vanadium-enriched phase, predominantly in a form of 2(Ca,Mn)O·V2O5, decreased along with more SiO2 and Fe2O3 in this phase; while, with increasing roasting time, the V2O5 concentration in the vanadium-enriched phase increased due to a more complete reaction. However, a higher calcium addition induced a lower V2O5 concentration in the vanadium-enriched phase and, therefore, a CaO/V2O5 weight ratio of 0.6 was employed. In addition to the vanadium-enriched phase, the solubilities, especially V2O5 in the SiO2 and Fe2O3 solid solutions under varying roasting conditions, were also identified for a reduction of vanadium loss. Based on those quantitative results, the main principles to target to adjust the elemental distributions among various phases during the calcium roasting of vanadium-bearing slags are discussed toward a low-cost and high-efficiency vanadium extraction. [ABSTRACT FROM AUTHOR]

Chromium, broadly present in metallurgical systems such as stainless steel slags and vanadium-bearing slags, tends to be in a trivalent form bound in spinel phases due to their ultrahigh stability. To explore the stability of chromium bearing spinels with different divalent cations, herein ACr2O4 (A=Mg, Zn, Mn) spinels were synthesized and stability-tested under both alkaline and acidic environments. X-ray diffraction (XRD) and refinement results reveal that MnCr2O4 exhibited the largest lattice parameters. X-ray photoelectron spectroscopy (XPS) results show that MnCr2O4 had the highest oxygen vacancy concentration, potentially triggering structural instability, consistent with the Fourier-transform infrared (FTIR) and Raman analyses. To further investigate the stability of ACr2O4 spinels in alkaline and acidic environments, we introduced CaO and SiO2, respectively, for high temperature calcinations. XRD analyses reveal that ACr2O4 spinels exhibited a high instability under an alkaline condition, with an increasing degree of instability for MgCr2O4, ZnCr2O4, and MnCr2O4 successively. We further quantified the relationship between the oxygen vacancy concentrations and the divalent cations containing in spinels as well as the spinel stabilities under an alkaline environment. Under an acidic condition, all ACr2O4 spinels demonstrated a relatively strong structural stability. The understanding of formation and stability of chromium bearing spinels under different conditions could contribute to potential modifications and applications of spinels especially with regard to resource recycling in metallurgy. [ABSTRACT FROM AUTHOR]

Purpose: We used proteomic sequencing and experimental verification to identify the potential ferroptosis-related proteins in ameloblastoma. Methods: Samples of ameloblastoma (n = 14) and normal gingival tissues (n = 5) were collected for proteomic sequencing to identify differentially expressed proteins (DEPs) in ameloblastoma. Ferroptosis-related genes were downloaded from FerrDb V2, which were then compared with DEPs to obtain ferroptosis-related DEPs (FR-DEPs). A functional enrichment analysis was performed, and a protein–protein interaction network was built. The hub proteins were screened using the Cytoscape software, and potential drugs targeting them were retrieved from the DrugBank database. A hub protein was selected for immunohistochemical validation, and its expression was assessed in ameloblastomas, odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. The primary ameloblastoma cells were cultured to explore the effect of the protein on the migratory properties of the tumour cells. Results: A total of 58 FR-DEPs were screened, and six hub proteins were identified: mTOR, NFE2L2, PRKCA, STAT3, EGFR, and CDH1. Immunohistochemical analysis showed that mTOR expression was upregulated in ameloblastomas compared with that in odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. p-mTOR was highly expressed in ameloblastomas, with a positivity rate of 83.3%. In addition, rapamycin, an inhibitor of mTOR, can inhibit the migratory capacity of primary cultured ameloblastoma cells. Conclusion: Our results revealed the ferroptosis-related proteins in ameloblastomas and their underlying biological processes. Additionally, mTOR was overexpressed and was found to be associated with the aggressiveness of ameloblastomas, which may be a potential target for future treatments. [ABSTRACT FROM AUTHOR]