AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms.METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L ...AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms.METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L for 24 h and at 0.125 and 0.25 nmol/L for 48 h before irradiation. Radiation doses were given from 0 to 10 Gy. Cell survival was measured by a standard clonogenic assay after a 9-d incubation. The reactive oxygen species (ROS) and glutathione (GSH) are detected after being given the same dose of docetaxel for the same time. RESULTS: The sensitization enhancement ratios (SER) for SMMC-7721 cells determined at the 50% survival level were 1.15, 1.21 and 1.49 at 0.125, 0.25, and 0.5 nmol/L for pre-incubation of 24 h, respectively; the SER were 1.42, 1.67 at 0.125 and 0.25 nmol/L, for pre-incubation of 48 h, respectively. The ROS of SMMC-7721 cells increased and GSH decreased after pretreatment with the same doses of docetaxel for 24 or 48 h.CONCLUSION: A radiosensitizing effect of docetaxel could be demonstrated unambiguously in this cell line used. In addition, our data showed that the mechanism of radiopotentiation by docetaxel probably does not involve a G2/M block in SMMC-7721 cells, and ROS generation and GSH deletion may play a key role in the radiosensitizing effect of docetaxel.展开更多
介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS...介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS工艺制造,测试验证结果表明,产品在满足使用要求的同时,具备抗电离总剂量3×10~3 Gy(Si)、抗中子注量0.6×10^(14) n·cm^(-2)的性能,适用于核辐射环境。辐射测试结果证明了设计的正确性。展开更多
文摘AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms.METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L for 24 h and at 0.125 and 0.25 nmol/L for 48 h before irradiation. Radiation doses were given from 0 to 10 Gy. Cell survival was measured by a standard clonogenic assay after a 9-d incubation. The reactive oxygen species (ROS) and glutathione (GSH) are detected after being given the same dose of docetaxel for the same time. RESULTS: The sensitization enhancement ratios (SER) for SMMC-7721 cells determined at the 50% survival level were 1.15, 1.21 and 1.49 at 0.125, 0.25, and 0.5 nmol/L for pre-incubation of 24 h, respectively; the SER were 1.42, 1.67 at 0.125 and 0.25 nmol/L, for pre-incubation of 48 h, respectively. The ROS of SMMC-7721 cells increased and GSH decreased after pretreatment with the same doses of docetaxel for 24 or 48 h.CONCLUSION: A radiosensitizing effect of docetaxel could be demonstrated unambiguously in this cell line used. In addition, our data showed that the mechanism of radiopotentiation by docetaxel probably does not involve a G2/M block in SMMC-7721 cells, and ROS generation and GSH deletion may play a key role in the radiosensitizing effect of docetaxel.
文摘介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS工艺制造,测试验证结果表明,产品在满足使用要求的同时,具备抗电离总剂量3×10~3 Gy(Si)、抗中子注量0.6×10^(14) n·cm^(-2)的性能,适用于核辐射环境。辐射测试结果证明了设计的正确性。
