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Cytotoxicity of polymethyl methacrylate cement on primary cultured metastatic spinal cells
Ji Fang,Jieliang Shen,Wei Jiang,Wen Dong,Zhenming Hu,Zhenming Hu 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.2
Polymethyl methacrylate (PMMA) bone cement has been commonly used for percutaneous injection into collapsed vertebral bodies due to malignant tumor. The purpose of this study was to investigate the possible mechanisms of PMMA’s cytotoxcity on primary cultured spinal metastastic cells (SMCs) in vitro. PMMA specimens were prepared in standard discs made of dough and polymerization stages, and the eluates were prepared following the ISO standard. Primary SMCs were obtained and isolated from 7 patients with spinal metastatic tumors undergoing vertebroplasty. Primary cultured SMCs were treated with PMMA specimens of different stages for 24 h, or co-cultured with extracted medium for successive 3 days. The temperatures in two locations from cement discs were recorded by K-type thermocouples. Furthermore, cell proliferation, apoptosis and cycles were determined by MTT and flow cytometry, respectively. The modulation of apoptotic proteins (bcl- 2, bax, caspase-3, caspase-8, Fas and PARP) and cell cycle proteins (cyclin D1, P21 and P27) were analyzed by western blot and real time PCR. The results of this study demonstrated that PMMA treatment was able to suppress SMCs proliferation, induce cell apoptosis and inhibit cell cycle arrest when compared to the control group in vitro (P<0.05). Simultaneously, the temperature recorded at the periphery of the PMMA specimen was not high enough to casue thermal injury. Furthermore, molecular markers of apoptosis including Fas, caspase-3 and caspase-9 activated, and Bcl-2/Bax dysregulated in the SMCs with PMMA stimulation. In addition, PMMA treatment showed decreased expression of cyclin D1 that induces cell cycle and increased epxression of inhibitory protein P21, with no significant difference of P27 expression. In summary, the present study confirms that PMMA cement can compromise the vitality and apoptosis of SMCs. This cytotoxic effect may be regulated by the biomarkers Fas, Bcl-2, Bax, caspase-3, caspase-9, cyclin D1 and P21, but not on account of thermal damage.
Total ionizing dose effect on graphene field effect transistors
Li Ji-fang,Guo Hong-Xia,Ma Wu-ying,Song Hong-jia,Zhong Xiang-li,Zhang Feng-qi,Li Yangfan,Bai Ruxue,Lu Xiaojie 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.12
In this work, the total-ionizing-dose (TID) efects on graphene feld efect transistors (GFETs) were investigated using 10 keV X-ray irradiation under various gate biases in irradiation environment. For reliability applications, the Dirac voltage (VDirac) shifted negatively during irradiation as the hole mobility (μh) and electron mobility (μe) declined under the positive gate and zero bias. Under negative gate bias, the Dirac voltage (VDirac) moved in a positive direction, reducing hole mobility (μh) and electron mobility (μe). Thus, we can conclude that the positive gate bias is the worst bias of GFETs by contrasting the experimental outcomes under various biases. During the recovery time of 9 h and 24 h after irradiation, and it became clear that the Dirac voltage (VDirac) shifted in a positive direction. Notably, the emergence of trap charges caused by irradiation, and the accumulation of trap charges can be used to explain these phenomena. The recovery time outcome data indicate that radiation damage was caused by the trap charge created during irradiation. Therefore, this work assists in the implementation of GFETs in challenging environments.