Search

Calcium pyroniobate (Ca2Nb2O7) as a kind of lead‐free piezoelectric material has been applied for different fields, but the study of isothermal and non‐isothermal growth behaviors of Ca2Nb2O7 in the molten slag is infrequent. In this paper, the in situ thermal analyzer with a single hot thermocouple technique (SHTT) is used to study the growth behaviors of Ca2Nb2O7 in molten slag. In the isothermal temperatures, the Ca2Nb2O7 presents two kinds of growth morphology, including three dimensional (3D) rhombus growth and fibrous one dimensional (1D) growth. The 3D rhombus is grown under the range of 1608 to 1628 K. When the temperature further decreases to 1593 K, the growth behavior of Ca2Nb2O7 becomes fibrous in 1D. Growth velocity affected by the degree of supercooling may account for the phenomenon of two kinds of growth behaviors in different temperatures. In the non‐isothermal growth process, the cooling rate over 10 K min−1 contributes to multiple crystal nucleuses growth of Ca2Nb2O7. The cooling rate below 5 K min−1 leads to single nuclear growth. This paper provides a control guideline for Ca2Nb2O7 growth. [ABSTRACT FROM AUTHOR]

Phase relationships of the Nb2O5-MgO-SiO2 system in equilibrium at 1673 K and 1523 K in air have been investigated by the high-temperature equilibration/quenching method. The compositions of equilibrium phase were determined by electron-probe X-ray microanalysis (EPMA) and X-ray diffraction (XRD). In this study, no ternary compounds were observed. The isothermal section of the system at 1673 K was triangulated into seven three-phase regions: SiO2-Nb2O5-Mg2/3Nb34/3O29, SiO2-Mg2/3Nb34/3O29-MgNb2O6, SiO2-MgSiO3-MgNb2O6, MgO-Mg2SiO4-Mg4Nb2O9, Mg2SiO4-MgNb2O6-Mg5Nb4O15, MgSiO3-Mg2SiO4-MgNb2O6, and Mg2SiO4-Mg5Nb4O15-Mg4Nb2O9. Similarly, the isothermal section at 1523 K was triangulated into six three-phase regions: SiO2-Nb2O5-MgNb2O6 region, SiO2-MgSiO3-MgNb2O6 region, MgO-Mg2SiO4-Mg4Nb2O9 region, Mg2SiO4-MgNb2O6-Mg5Nb4O15 region, MgSiO3-Mg2SiO4-MgNb2O6 region, and Mg2SiO4-Mg5Nb4O15-Mg4Nb2O9 region. The determination of the Nb2O5-MgO-SiO2 ternary system further enriches the thermodynamic databases of silicates and niobates. [ABSTRACT FROM AUTHOR]

The redox homeostasis system regulates many biological processes, intracellular antioxidant production and redox signaling. However, long noncoding RNAs (lncRNAs) involved in redox regulation have rarely been reported. Herein, we reported that downregulation of MAGI2-AS3 decreased the superoxide level in Human fibroblasts (Fbs), a replicative aging model, as detected by the fluorescent probes dihydroethidium (DHE) and MitoSOX™ Red. RNA pulldown combined with mass spectrometry showed that HSPA8 is a novel interacting protein of MAGI2-AS3, which was further confirmed by photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP). Downregulation of MAGI2-AS3 decreased the hydrogen peroxide (H 2 O 2 ) content by stabilizing the HSPA8 protein level via inhibiting the protesome degradation of HSPA8. Further evidence showed that MAGI2-AS3 interacted with the C-terminal domain (CTD) of HSPA8. Downregulation of MAGI2-AS3 delayed cell senescence, while this antiaging effect was abolished by HSPA8 knockdown. The underlying molecular mechanism by which MAGI2-AS3 knockdown inhibited cell senescence was mediated via suppression of the ROS/MAP2K6/p38 signaling pathway. Taken together, these findings revealed that downregulation of lncRNA MAGI2-AS3 decreased the H 2 O 2 content and delayed cell senescence by stabilizing the HSPA8 protein level, identifying a potential antiaging application., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Interfacial photogenerated charge separation and transport have demonstrated great influence on photocatalytic performance. Herein, the composite photocatalysts of methylammonium lead iodide perovskite (MAPbI 3 ) in TiO 2 with a hollow multishell structure (HoMS) are designed and synthesized. The results indicate that the heterogeneous interface within the MAPbI 3 /Pt/TiO 2 -HoMS can help enhance the separation of photogenerated charges. HoMSs assembled with multiple shells can not only support large surfaces available for building a heterogeneous interface and photocatalytic reactions but also improve the light absorption capability of photocatalysts. Besides, the thin shell structure can also reduce the transmission distance of carriers so as to hinder charge recombination and improve charge utilization. As a result, samples of MAPbI 3 /Pt/triple-shelled TiO 2 hollow structure displayed a H 2 yield of 6856.2 μmol h -1 g -1 under visible light, which is greatly better than that of bare MAPbI 3 (268.6 μmol h -1 g -1 ).