Hyperthermia has been a modality to treat cancer for thousands of years. During this time, intensive efforts are concentrated on determining the dose of the proper treatment, but the dominantly in vitro induced cellul...Hyperthermia has been a modality to treat cancer for thousands of years. During this time, intensive efforts are concentrated on determining the dose of the proper treatment, but the dominantly in vitro induced cellular death does not provide enough confidence for the clinical dosing. The cell-death by heat-monotherapy applications in laboratory experiments is difficult to apply in the complementary therapies in clinical applications. The newly developed nanotechnologies offer completely new possibilities in this field as well. Modulated electro-hyperthermia (mEHT, trade-name Oncothermia) is a nanoheating technology that has selective effects on membrane rafts and on the transmembrane proteins. This effect is thermal. The thermal action is in nanoscopic range which makes the phenomenon special. Our objective is to show the dose concept on this emerging method.展开更多
The Chinese Academy of Science has launched a thorium-based molten-salt reactor(TMSR)research project with a mission to research and develop a fission energy system of the fourth generation.The TMSR project intends to...The Chinese Academy of Science has launched a thorium-based molten-salt reactor(TMSR)research project with a mission to research and develop a fission energy system of the fourth generation.The TMSR project intends to construct a liquid fuel molten-salt reactor(TMSR-LF),which uses fluoride salt as both the fuel and coolant,and a solid fuel molten-salt reactor(TMSR-SF),which uses fluoride salt as coolant and TRISO fuel.An optimized 2 MWth TMSR-LF has been designed to solve major technological challenges in the Th-U fuel cycle.Preliminary conceptual shielding design has also been performed to develop bulk shielding.In this study,the radiation dose and temperature distribution of the shielding bulk due to the core were simulated and analyzed by performing Monte Carlo simulations and computational fluid dynamics(CFD)analysis.The MCNP calculated dose rate and neutron and gamma spectra indicate that the total dose rate due to the core at the external surface of the concrete wall was 1.91μSv/h in the radial direction,1.16μSv/h above and 1.33μSv/h below the bulk shielding.All the radiation dose rates due to the core were below the design criteria.Thermal analysis results show that the temperature at the outermost surface of the bulk shielding was 333.86 K,which was below the required limit value.The results indicate that the designed bulk shielding satisfies the radiation shielding requirements for the 2 MWth TMSR-LF.展开更多
为探究电子束剂量率对充氮包装冷鲜牛肉蛋白结构和理化性质的影响,用高能电子加速器辐照处理黄牛背最长肌,然后于4℃条件贮藏25 d,以2.5 k Gy辐照剂量,研究辐照组(辐照剂量率分别为30、150、300 k Gy/min)和对照组对肌原纤维蛋白二级结...为探究电子束剂量率对充氮包装冷鲜牛肉蛋白结构和理化性质的影响,用高能电子加速器辐照处理黄牛背最长肌,然后于4℃条件贮藏25 d,以2.5 k Gy辐照剂量,研究辐照组(辐照剂量率分别为30、150、300 k Gy/min)和对照组对肌原纤维蛋白二级结构、肌肉热稳定性和相关理化性质的影响。结果表明:辐照组和对照组相比,表面活性巯基质量摩尔浓度显著下降,在贮藏第0天,辐照组的活性巯基质量摩尔浓度分别下降了19.05%、22.00%和22.60%,差异显著(P<0.05);电子束处理使肌原纤维蛋白疏水性和溶解度下降,α-螺旋和β-折叠结构含量减少,无规卷曲和β-转角结构含量增加,蛋白质的无序程度增加;电子束处理组肌球蛋白氧化变性降解,对热稳定性下降。电子束处理改变了牛肉肌原纤维蛋白的结构,由此导致其某些理化性质发生变化,进而对其品质产生一定的影响,而150 k Gy/min剂量率的处理对牛肉蛋白结构和品质的影响相对较小。展开更多
文摘Hyperthermia has been a modality to treat cancer for thousands of years. During this time, intensive efforts are concentrated on determining the dose of the proper treatment, but the dominantly in vitro induced cellular death does not provide enough confidence for the clinical dosing. The cell-death by heat-monotherapy applications in laboratory experiments is difficult to apply in the complementary therapies in clinical applications. The newly developed nanotechnologies offer completely new possibilities in this field as well. Modulated electro-hyperthermia (mEHT, trade-name Oncothermia) is a nanoheating technology that has selective effects on membrane rafts and on the transmembrane proteins. This effect is thermal. The thermal action is in nanoscopic range which makes the phenomenon special. Our objective is to show the dose concept on this emerging method.
基金Supported by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(No.XD02005002)
文摘The Chinese Academy of Science has launched a thorium-based molten-salt reactor(TMSR)research project with a mission to research and develop a fission energy system of the fourth generation.The TMSR project intends to construct a liquid fuel molten-salt reactor(TMSR-LF),which uses fluoride salt as both the fuel and coolant,and a solid fuel molten-salt reactor(TMSR-SF),which uses fluoride salt as coolant and TRISO fuel.An optimized 2 MWth TMSR-LF has been designed to solve major technological challenges in the Th-U fuel cycle.Preliminary conceptual shielding design has also been performed to develop bulk shielding.In this study,the radiation dose and temperature distribution of the shielding bulk due to the core were simulated and analyzed by performing Monte Carlo simulations and computational fluid dynamics(CFD)analysis.The MCNP calculated dose rate and neutron and gamma spectra indicate that the total dose rate due to the core at the external surface of the concrete wall was 1.91μSv/h in the radial direction,1.16μSv/h above and 1.33μSv/h below the bulk shielding.All the radiation dose rates due to the core were below the design criteria.Thermal analysis results show that the temperature at the outermost surface of the bulk shielding was 333.86 K,which was below the required limit value.The results indicate that the designed bulk shielding satisfies the radiation shielding requirements for the 2 MWth TMSR-LF.
文摘为探究电子束剂量率对充氮包装冷鲜牛肉蛋白结构和理化性质的影响,用高能电子加速器辐照处理黄牛背最长肌,然后于4℃条件贮藏25 d,以2.5 k Gy辐照剂量,研究辐照组(辐照剂量率分别为30、150、300 k Gy/min)和对照组对肌原纤维蛋白二级结构、肌肉热稳定性和相关理化性质的影响。结果表明:辐照组和对照组相比,表面活性巯基质量摩尔浓度显著下降,在贮藏第0天,辐照组的活性巯基质量摩尔浓度分别下降了19.05%、22.00%和22.60%,差异显著(P<0.05);电子束处理使肌原纤维蛋白疏水性和溶解度下降,α-螺旋和β-折叠结构含量减少,无规卷曲和β-转角结构含量增加,蛋白质的无序程度增加;电子束处理组肌球蛋白氧化变性降解,对热稳定性下降。电子束处理改变了牛肉肌原纤维蛋白的结构,由此导致其某些理化性质发生变化,进而对其品质产生一定的影响,而150 k Gy/min剂量率的处理对牛肉蛋白结构和品质的影响相对较小。
