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The aim of achieving integration of lightweight, high strength, high‐temperature resistant, and satisfactory electromagnetic (EM) wave absorption was successfully accomplished in the present study by synthesizing TiC–TiB2 fibers reinforced Si3N4 composites, which were pressureless sintered at 1650°C for 2 h. The preparation of TiC–TiB2 fibers was conducted through a chloride‐assisted carbothermic method. This work focused on investigating the effects of incorporating TiC–TiB2 fibers on the mechanical properties and EM wave absorption characteristics of the composites. The 30 wt% TiC–TiB2/Si3N4 composite displayed the bulk density of 1.89 g/cm3, bending strength of 93.11 ± 3.91 MPa, fracture toughness of 1.81 ± 0.10 MPa m1/2, minimum reflection loss of −38.87 dB, and effective absorption bandwidth of 1.43 GHz in the Ku‐band, respectively. The as‐synthesized TiC–TiB2/Si3N4 composites are promising candidates for EM wave absorbing load‐bearing materials due to their outstanding mechanical properties and microwave absorption properties. [ABSTRACT FROM AUTHOR]

In view of the lack of conformal, load‐bearing, light‐weight, and high temperature‐resistant integrated wave‐absorbing composites suitable for extremely complex conditions, the gel‐casting process was successfully applied to porous Si3N4 wave‐absorbing composites in this work. A universal low‐slurry for gel casting was prepared by using two dispersants acting together (tetramethylammonium hydroxide solution and sodium lauryl sulfate), which ensured the smooth completion of the gel casting process. Combining the thermogravimetric and differential thermal gravity curves of the composite green body, reasonable parameters of the rubber discharge process are given to avoid the problem of the green body swelling and cracking. The porous TiC/Si3N4 composites were successfully prepared by holding them at 1650°C for 3 h. The bending strength, density, minimum reflection loss, absorption bandwidth, and matched thickness in the P‐band of the composites with 30 wt.% TiC addition were 54.08 ± 3.02 MPa, 1.906 g/cm3, ‐37.75 dB, 1.9 GHz, and 4.1 mm, respectively. The electromagnetic wave loss mechanisms of the composites are a combination of conductivity loss, multiple reflections and scattering, interfacial polarization, and defect polarization. [ABSTRACT FROM AUTHOR]

The boron nitride nanosheets (BNNSs)/aluminum nitride (AlN) composites were prepared by hot press sintering at 1600°C. The microstructure, mechanical properties, and thermal conductivity of the samples were measured, and the effect of adding BNNSs to AlN ceramics on the properties was studied. It is found that the addition of BNNSs can effectively improve the mechanical properties of AlN. When the additional amount is 1 wt%, the bending strength of the sample reaches the maximum value of 456.6 MPa, which is 23.1% higher than that of the AlN sample without BNNSs. The fracture toughness of the sample is 4.47 MPa m1/2, a 68.7% improvement over the sample without BNNSs. The composites obtained in the experiment have brilliant mechanical properties. [ABSTRACT FROM AUTHOR]

Upconversion (UC) luminescence modulation is quite important in controlling and processing light for active components of light sources, photoswitches, optical memories, and optical sensing devices. In this work, we reported one kind of novel phosphor, Ho3+/Yb3+‐doped SrBi4Ti4O15 ceramics, which displayed both strong UC luminescence and obvious photochromic (PC) reaction. The UC luminescence, PC effect, and the modulation of UC performance based on PC behavior were investigated in detail. By alternating visible light irradiation and thermal stimulus, the UC luminescence could be reversibly regulated. Meanwhile, the modulation was unveiled to tightly rely on the irradiation time and thermal treatment processes. Excellent reproducibility was also achieved. In addition, as an alternative method to thermal treatment, the manipulation of luminescence by electric field was also explored. Finally, the mechanism related to the UC luminescence manipulation was illustrated. The results indicate that these samples could be potentially utilized in optical data storage and anti‐counterfeiting security fields. [ABSTRACT FROM AUTHOR]

Objectives Emerging studies have demonstrated that micro RNAs (mi RNAs) play crucial roles in carcinogenesis of many developing human tumours. However, the functions and mechanisms of miR-297 in lung cancer have, up to now, been largely undefined. Materials and methods Here, miR-297 expression was measured in lung adenocarcinoma tissues and cell lines, using qRT- PCR. Lung adenocarcinoma cell line was treated with an miR-297 mimic. MTT and colony analysis were performed to detect cell proliferation and colony formation. The direct target gene of miR-297 was assessed by qRT- PCR, Western blotting and luciferase assays. Results We demonstrated that miR-297 expression was upregulated in lung adenocarcinomas compared to adjacent normal tissues. Expression of miR-297 was also upregulated in tested lung adenocarcinoma cell lines. Ectopic expression of miR-297 enhanced lung adenocarcinoma cell proliferation and colony formation. Furthermore, overexpression of miR-297 promoted cell migration and invasion. In addition, we identified Glypican-5 ( GPC5) as a direct target gene of miR-297 in lung adenocarcinoma cells. Expression of GPC5 was downregulated in both lung adenocarcinoma tissues and cell lines. Moreover, expression of GPC5 was inversely associated with expression of miR-297 in lung adenocarcinoma tissues. Conclusions These results suggest that miR-297 acted as an oncogenic mi RNA, partly by targeting GPC5, adenocarcinoma of the lung. [ABSTRACT FROM AUTHOR]