Progenitor Cell Isolation From Mouse Epididymal Adipose Tissue and Sequencing Library Construction

Here, we present a protocol to isolate progenitor cells from mouse epididymal visceral adipose tissue and construct bulk RNA and assay for transposase-accessible chromatin with sequencing (ATAC-seq) libraries. We describe steps for adipose tissue collection, cell isolation, and cell staining and sorting. We then detail procedures for both ATAC-seq and RNA sequencing library construction. This protocol can also be applied to other tissues and cell types directly or with minor modifications. For complete details on the use and execution of this protocol, please refer to Liu et al. (2023).1 *1 Liu, Q., Li, C., Deng, B., Gao, P., Wang, L., Li, Y., ... & Fu, X. (2023). Tcf21 marks visceral adipose mesenchymal progenitors and functions as a rate-limiting factor during visceral adipose tissue development. Cell reports, 42(3) 112166. https://doi.org/10.1016/j.celrep.2023.11216

Dietary Sea Buckthorn Pomace Induces Beige Adipocyte Formation in Inguinal White Adipose Tissue in Lambs

The sea buckthorn contains substantial amounts of bioactive compounds. The objective of this study was to investigate the effects of dietary sea buckthorn pomace (SBP) on sheep beige adipocyte formation. A total of thirty lambs were equally divided into three groups and fed with diets containing different levels of SBP: 0% SBP (Control), 7.8% SBP (7.8SBP), and 16.0% SBP (16SBP). The results showed that dietary SBP affected inguinal adipocytes’ size distribution, and increased both UCP1 protein content (p < 0.05) and mitochondrial numbers (p < 0.05). mRNA expression of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), nuclear respiratory factor 1, and mitochondrial transcription factor A were increased when animals were subjected to 16% SBP (p < 0.05). Supplementation with 16% SBP increased CCAAT/enhancer-binding protein β content (p < 0.05) and PR domain containing 16 mRNA abundance (p < 0.05). Consistently, inguinal white adipose tissue (iWAT) from the 16SBP group exhibited increased insulin sensitivity, which was associated with elevated glucose transporter 4 abundance (p < 0.05). Importantly, AMP-activated protein kinase (AMPK) was activated in the 16SBP group (p < 0.05). Collectively, these results suggest that dietary SBP promotes iWAT browning in lambs, which might be through the activation of the AMPK–PGC-1α–UCP1 signaling pathway

Recent development of high-entropy transitional carbides: a review

The high-entropy carbides (HECs) are reviewed in terms of the crystal structure, powder synthesis, densification, and mechanisms in this article. The inter-diffusion rate of binary carbide is mainly analyzed and predicted based on lattice parameters. During the solid solution formation progress, the densification methods usually adopted were hot pressing and spark plasma sintering. It was found that the distribution of metal atoms was more uniform in high-entropy powders derived from binary carbide raw materials. HECs displayed higher hardness, elastic modulus, and oxidation resistance, and meanwhile exhibited lower thermal conductivity compared to binary carbides. HECs are expected to be used as high-speed atmospheric re-entry vehicles. (C) 2020 The Ceramic Society of Japan. All rights reserved

Harmonized toughening and strengthening in pressurelessly reactive-sintered Ta0.8Hf0.2C-SiC composite

Ta0.8Hf0.2C-27 vol%SiC (99.0% in relative density) composite was toughened and strengthened via pressurelessly in-situ reactive sintering process. HfC and beta-SiC particles were formed after reaction of HfSi2 and carbon black at 1650 degrees C. Ta0.8Hf0.2C was obtained from solid solutioning of HfC and commercial TaC. The beta-alpha phase transformation of SiC proceeded below 2200 degrees C. High aspect ratio, platelet-like alpha-SiC grains formed and interconnected as interlocking structures. Toughness and flexural strength values of 5.4 +/- 1.2 MPa m(1/2) and 443 +/- 22 MPa were measured respectively. The toughening mechanisms by highly directional growth of discontinuous alpha-SiC grains were crack branching, bridging and deflection behaviors

Harmonized toughening and strengthening in pressurelessly reactive-sintered Ta0.8Hf0.2C-SiC composite

Ta0.8Hf0.2C-27 vol%SiC (99.0% in relative density) composite was toughened and strengthened via pressurelessly in-situ reactive sintering process. HfC and beta-SiC particles were formed after reaction of HfSi2 and carbon black at 1650 degrees C. Ta0.8Hf0.2C was obtained from solid solutioning of HfC and commercial TaC. The beta-alpha phase transformation of SiC proceeded below 2200 degrees C. High aspect ratio, platelet-like alpha-SiC grains formed and interconnected as interlocking structures. Toughness and flexural strength values of 5.4 +/- 1.2 MPa m(1/2) and 443 +/- 22 MPa were measured respectively. The toughening mechanisms by highly directional growth of discontinuous alpha-SiC grains were crack branching, bridging and deflection behaviors

Effect of volume ratio on the performance of mid-wave infrared transparent Gd2O3–MgO composite ceramics

Gd2O3–MgO composite ceramics are promising candidates for preparing protective mid-wave infrared (MWIR) windows. However, owing to the different crystal structures of Gd2O3 and MgO after the sintering process, the volume ratio of the two phases must be controlled more precisely to achieve optimum performance. In this study, a nitrate-citrate combustion method was used to prepare Gd2O3–MgO nanopowders with different volume ratios, and composite ceramics were then fabricated via low-temperature pre-sintering and subsequent hot isostatic pressing (HIP). The effect of the Gd2O3:MgO volume ratio on the sintering behaviour, microstructures and optical, thermal and mechanical properties of the composite ceramics was studied in detail. A comprehensive assessment of the above-mentioned properties indicated that the Gd2O3–MgO composite ceramic with a volume ratio of 2:3, which exhibited a transmittance of 80.1–85.8% in the range of 3–5 μm, thermal conductivity of 17.5 W m−1 K−1, Vickers hardness of 9.8 GPa and toughness of 1.84 MPa m1/2, displays the optimum application performance for MWIR windows

Shrinkage features, microstructure evolution and properties of Gd2O3-MgO optical composite ceramics with Zr as phase stabilizer

A novel composite ceramic, composed of equal-volumetric Zr-stabilized Gd2O3 and MgO phases, was prepared to be transparent in mid-wave infrared range. Zr stabilized Gd2O3 is proved to have a lower lattice parameter (10.7516Å) using XRD refinement. Pressureless sintering behavior of Gd2O3-MgO with/without 2at.% Zr-doping (naming ZGM and GM) was studied via the real-time observation technique. The shrinkage of ZGM green body proceeds steadily up to 1400°C while that of the undoped one shrinks sharply at 1250°C due to Gd2O3 phase transition. The segregation of Zr element along the grain boundaries of Zr-Gd2O3 creates a synergized effect on the grain refinement with pinning effect. Dense ZGM ceramics exhibit superior transmittance of 78.3%‐85.6% at 3-5 μm, which show good consistency with the calculated values. The refractive index of Zr- Gd2O3 varies from 1.87 at 3 μm to 1.80 at 5 μm, which is smaller than those of monoclinic Gd2O3

Thermal properties and calcium-magnesium-alumino-silicate (CMAS) interaction of novel γ-phase ytterbium-doped yttrium disilicate (γ-Y1.5Yb0.5Si2O7) environmental barrier coating material

Rare-earth disilicates are promising candidates for thermal and environmental barrier coatings (TEBC) in gas turbines that safeguard SiCf/SiC ceramic matrix composites (CMCs) from thermal degradation and environmental attacks. Here, we report a systematic investigation on novel TEBC material, γ-Y1.5Yb0.5Si2O7. The γ-phase quarter molar ytterbium–doped yttrium disilicate exhibited low thermal conductivity (1.72 W·m−1·K−1 at 1200 °C) and reduced intrinsic thermal expansion (3.17 ± 0.22 × 10−6 K−1 up to 1000 °C), ensuring promisingly effective thermal insulation and minimized thermal stress with CMC substrates. Using density functional theory (DFT), the heat capacity of γ-Y1.5Yb0.5Si2O7 was predicted higher than that of undoped γ-Y2Si2O7. Comparing these predictions to results calculated using the Neumann–Kopp (NK) rule revealed only minor variations. A metastable CMAS interaction byproduct, cyclosilicate phase Ca3RE2(Si3O9)2, was identified based on energy dispersive X-ray spectrometer (EDS) and electron backscatter diffraction (EBSD) techniques, appearing at 1300 °C but disappearing at 1400 °C. The γ-Y1.5Yb0.5Si2O7 exhibited good CMAS resistance on both dense pellets and sprayed coatings, forming a protective apatite (Ca2RE8(SiO4)6O2) interlayer that effectively hindered CMAS infiltration at evaluated temperatures. The relatively higher Y:Yb atomic ratio (> 3) in the apatite grains indicate differential reactivity with molten CMAS and provides crucial insights into the CMAS corrosion mechanism. These findings highlight the potential of γ-Y1.5Yb0.5Si2O7 as a CMC coating material, emphasizing the need for tailored microstructural optimization as a thermal sprayed coating to enhance long-term performance in extreme gas turbine environments