Bi-doped barium ferrite decorated polythiophene nanocomposite: influence of Bi-doping on structure, morphology, thermal and EMI shielding behavior for X-band
JOURNAL OF MATERIALS SCIENCE
Authors: Iqbal, Sajid; Khatoon, Halima; Kotnala, R. K.; Ahmad, Sharif
Abstract
The electronic and communication devices such as mobile, laptop, and radio ease our day-to-day life. However, these devices emit harmful radiation, which affects human health and the environment. Therefore, to prevent such radiation-based pollution and provide a safer working environment, viable and promising EMI shielding materials have been investigated. Keeping this in mind, the present work reports the relatively low-temperature synthesis of bismuth-doped barium ferrite (BaBixFe12-xO19, Bi-BFO) nanoparticles and their nanocomposite via sol-gel and in situ emulsion polymerization approaches for their application in EMI shielding material. The influence of Bi-doping on phase purity, morphology, structure, and thermal behavior has been explored. The EMI shielding properties of these materials have been investigated in the X-band (8.2-12.4 GHz) region. The composite (Bi-BFO:PT = 2:1 Bi-BFO/PTh-21) with 1 mm thickness exhibited maximum shielding effectiveness (SE) of - 47.12 dB in the X-band region. The high shielding activity is mainly due to the efficient complementarities between the magnetic and dielectric loss. The doping of Bi in barium ferrite results in the increase in electrical polarization that led to the high dielectric loss, causing higher absorption of electromagnetic (EM) waves. These studies suggest that the nanocomposite may find its scope as an excellent microwave absorber for a wide frequency region. [GRAPHICS] .
PTH(1-34) activates the migration and adhesion of BMSCs through the rictor/mTORC2 pathway
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
Authors: Lv, Zhong; Muheremu, Aikeremujiang; Bai, Xiaochun; Zou, Xuenong; Lin, Tao; Chen, Bailing
Abstract
The ability of intermittent parathyroid hormone (1-34) [PTH(1-34)] treatment to enhance bone-implant osseo-integration was recently demonstrated in vivo. However, the mechanisms through which PTH (1-34) regulates bone marrow-derived stromal cells (BMSCs) remain unclear. The present study thus aimed to investigate the effects of PTH(1-34) on the migration and adhesion of, and rictor/mammalian target of rapamycin complex 2 (mTORC2) signaling in BMSCs. In the present study, BMSCs were isolated from Sprague-Dawley rats treated with various concentrations of PTH(1-34) for different periods of time. PTH(1-34) treatment was performed with or without an mTORC1 inhibitor (20 nM rapamycin) and mTORC1/2 inhibitor (10 mu M PP242). Cell migration was assessed by Transwell cell migration assays and wound healing assays. Cell adhesion and related mRNA expression were investigated through adhesion assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively. The protein expression of chemokine receptors (CXCR4 and CCR2) and adhesion factors [intercellular adhesion molecule 1 (ICAM-1), fibronectin and integrin beta 1] was examined by western blot analysis. The results revealed that various concentrations (1, 10, 20, 50 and 100 nM) of PTH(1-34) significantly increased the migration and adhesion of BMSCs, as well as the expression of CXCR4, CCR2, ICAM-1, fibronectin and integrin beta 1. In addition, the p-Akt and p-S6 levels were also upregulated by PTH(1-34). BMSCs subjected to mTORC1/2 signaling pathway inhibition or rictor silencing exhibited a markedly reduced PTH-induced migration and adhesion, while no such effect was observed for the BMSCs subjected to mTORC1 pathway inhibition or raptor silencing. These results indicate that PTH(1-34) promotes BMSC migration and adhesion through rictor/mTORC2 signaling in vitro. Taken together, the results of the present study reveal an important mechanism for the therapeutic effects of PTH(1-34) on bone-implant osseointegration and suggest a potential treatment strategy based on the effect of PTH(1-34) on BMSCs.