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SiC fiber-bonded ceramics (FBCs), as a new thermal-structural material obtained by hot-pressing sintering of SiC fiber, has low porosity, high fiber volume fraction, high temperature resistance, oxidation resistance and high strength. It is an excellent candidate material for high temperature components such as turbine blades and rotors of aero-engine. The research progresses of FBCs were systematically reviewed in this paper. The structural characteristics and preparation methods of two types of FBCs (Tyranohex and SA Tyranohex) were introduced, the relationships among the composition, structure and performance of FBCs were discussed. It was noted that the interface carbon layer plays a crucial role in the performance of FBCs. The mechanical properties of SA-Tyranohex at room temperature and high temperature were highlighted, and the reasons for its excellent high temperature performance were analysed. The examination, verification and application development were summarized. The difficulties of FBCs in forming complex components were pointed out, and the future development trends and research directions were prospected. Finally, it was proposed that conducting research on SiC fiber-bonded ceramics is of great significance for the development of new materials for high-temperature resistant components in China.

A strong and tough Ta/TaHfC2‐laminated composite was proposed and investigated in terms of its thermoablative behavior under plasma flame for a medium–long time (30–120 s) beyond 2517 K. In comparison to TaHfC2, the composite performed a better thermal shock resistance but an equivalent linear ablation rate (−5.40 vs. −4.08 μm/s) after ablation for 30 s. With extending the ablation time, the linear ablation rate of the composite increases. Combined with the characterization results of the ablative layer and the established volatile phase diagram at 2273 K, it was found that the composite mainly undergoes active oxidation, passive oxidation, and dissolution of oxygen during the ablation, whereas its ablative layer mainly experiences the sintering, solid solution, and loss processes of oxides. The reason the composite possesses a good ablation resistance is because the introduction of Ta‐foil‐improved toughness as well as protective effect of the ablative layer of TaHfC2. [ABSTRACT FROM AUTHOR]

Ta‐Hf‐C ternary ceramics are good candidates for structural components used in extreme thermal environment. However, intrinsic brittleness greatly restricts their applications in reality. Here, we report a novel TaHfC2‐based composite with superior strength and toughness by employing Ta foil as interlayers to generate a multi‐scale laminated structure together with the in situ formed Ta2C MXene during sintering. Owing to the unique composition and microstructure, the tensile strength, shear strength, fracture toughness (KIC), and work of fracture of Ta/TaHfC2 have reached 233 ± 12 MPa, 64 ± 6 MPa, 13.16 ± 0.03 MPa·m1/2, and 1726 ± 448 J/m2 simultaneously, and all showed substantial increments when compared with TaHfC2 monolithic ceramic and related Ta‐Hf‐C materials as showed in literatures. This study significantly improved the toughness of TaHfC2, and it provides a new high‐performance thermal structural material for the aerospace industry as well as a new idea for toughening ultra‐high temperature ceramics (UHTCs) of transition metal carbides. [ABSTRACT FROM AUTHOR]

The effects of Citri Reticulatae Pericarpium (CRP) and grapefruit juice (GFJ) on the pharmacokinetics of omeprazole were investigated in this study. Sprague–Dawley rats were pretreated with CRP decoction or GFJ for 28 consecutive days. After a single intragastric administration of 6.0 mg/kg, the concentration of omeprazole in the plasma was determined by high‐performance liquid chromatography (HPLC), and the pharmacokinetic parameters were calculated by Kinetica software 5.0. A high‐performance liquid chromatography‐quadrupole‐time‐of‐flight mass spectrometry (HPLC‐Q‐TOF‐MS) method was established to identify the chemical components in CRP decoction and GFJ. The results showed that the AUCt–∞ was significantly increased when coadministrated with CRP. The AUC0‐t and AUC0–∞ was remarkably increased; the Cl was decreased when coadministrated with GFJ. A total of 31 and 28 bioactive compounds were identified in the CRP decoction and GFJ, respectively. Flavonoids and furanocoumarins, including hesperidin, hesperetin, naringenin, sinensetin, tangeretin, nobiletin, and 6′,7′‐dihydroxybergamottin, were simultaneously identified in CRP decoction and GFJ. This study indicates that the increased bioavailability of omeprazole may be due to the inhibition of hepatic cytochrome P450 enzymes, and the systemic exposure should be monitored when concomitant administration with CRP and GFJ. Practical applications: Citri Reticulatae Pericarpium (CRP) has been widely consumed as a daily condiment, functional food, and a traditional Chinese medicine. Omeprazole, primary metabolized by CYP450 enzymes, was usually coadministered with CRP for the treatment of gastrointestinal disease. Studies have confirmed that much fruit juices, including grapefruit juice, may affect drug metabolism enzymes. CRP and grapefruit (Citrus paradisi Macf.) belong to the genus Citrus and family Rutaceae with different species. Therefore, the pharmacokinetic interaction of CRP decoction and grapefruit juice with omeprazole is worthy of attention. The results of this study can provide basic pharmacological data support for the safe and effective clinical use of omeprazole. It can also provide a theoretical basis for the development of new functional products and daily application of CRP. [ABSTRACT FROM AUTHOR]

Background: Asthma imposes a heavy burden due to its high prevalence. Forkhead box O4 (FoxO4) proteins participate in the modulation of cell progression. However, the role and mechanism of FoxO4 in asthma remains uncharted., Methods: An allergic asthma model was constructed by the induction of ovalbumin and interleukin (IL)-4 in mice and monocyte/macrophage-like Raw264.7 cells, respectively. The role and mechanism of FoxO4 in asthma was determined by pathological staining, immunofluorescence assay, measurement of inflammatory cells in the blood, reverse transcription quantitative polymerase chain reaction (RT-qPCR), Western blot analysis, and flow cytometry., Results: Ovalbumin treatment triggered an obvious inflammatory cell infiltration with a prominent increase in F4/80 + cell numbers. The relative messenger RNA (mRNA) and protein expressions of FoxO4 were increased in both ovalbumin-induced mice and interleukin-4 (IL-4)-induced Raw264.7 cells. Inhibition of FoxO4 via AS1842856 reduced inflammatory cell infiltration, the number of Periodic Acid Schiff+ (PAS+) goblet cells, the numbers of inflammatory cells in the blood, and the airway resistance in ovalbumin-induced mice. Besides, interference of FoxO4 decreased the number of F4/80 + CD206 + cells, and the relative protein expressions of CD163 and Arg1 in vivo and in vitro . Mechanically, suppression of FoxO4 diminished the relative mRNA and protein expressions of LXA4R in both ovalbumin-induced mice and IL-4-induced Raw264.7 cells. Overexpression of LXA4R reversed the outcomes caused by repression of FoxO4, including airway resistance, the number of F4/80+ cells, the proportion of CD206+ cells in ovalbumin-induced mice, and the proportion of F4/80 + CD206 + cells in IL-4-induced Raw264.7 cells., Conclusion: FoxO4/LXA4R axis mediated macrophage M2 polarization in allergic asthma., Competing Interests: The authors state that there were no conflicts of interest to disclose.Tong Yua, Yiping Yua, Yingyu Mab, Guoqing Chen

Background: Pediatric asthma is a common chronic disease of childhood with airway inflammation. Cyclic adenosine monophosphate response element binding protein (CREB) plays a significant role in the transcription of proinflammatory genes, but its role in pediatric asthma has remained unclear. Herein, we investigated the functions of CREB in pediatric asthma., Methods: Eosinophils were purified from the peripheral blood of interleukin 5 (IL5) transgenic (IL5T) neonatal mice. The contents of CREB, long-chain fatty-acid-CoA ligase 4, transferrin receptor protein 1, ferritin heavy chain 1, and glutathione peroxidase 4 in eosinophils were examined by Western blot analysis. The viability of eosinophils, and the mean fluorescence intensity of Siglec F, C-C motif chemokine receptor 3 (CCR3), and reactive oxygen species were examined by flow cytometry. The concentration of iron in eosinophils was assessed by a commercial kit. The contents of malondialdehyde, glutathione, glutathione peroxidase, IL-5, and IL-4 were discovered by enzyme-linked-immunosorbent serologic assay. The C57BL/6 mice were randomly divided into four groups: sham, ovalbumin (OVA), OVA+Ad-shNC, and OVA+Ad-shCREB. The bronchial and alveolar structures were evaluated by hematoxylin and eosin staining. Leukocytes and eosinophils in the blood were measured using a HEMAVET 950., Results: The abundance of CREB in eosinophils was enhanced by CREB overexpression vector transfection, but reduced by short hairpin (sh)CREB transfection. Downregulation of CREB triggered the cell death of eosinophils. Knockdown of CREB could obviously contribute to ferroptosis of eosinophils. In addition, downregulation of CREB facilitated dexamethasone (DXMS, a type of glucocorticoid)-induced eosinophils death. Moreover, we established an asthma mouse model by OVA treatment. The CREB was upregulated in OVA group mice, but Ad-shCREB treatment obviously downregulated CREB level. Downregulation of CREB diminished OVA-induced asthmatic airway inflammation by reducing the number of inflammatory cells and the levels of proinflammatory factors. Downregulated CREB enhanced the anti-inflammatory effect of DXMS in OVA-induced mice., Conclusion: Inhibition of CREB promoted the effect of glucocorticoids on airway inflammation in pediatric asthma through promoting ferroptosis of eosinophils., Competing Interests: The authors stated that there was no conflict of interest to disclose.